FIPS DRBG digest/hmac/CTR

17 files changed, 3990 insertions, 0 deletions

diff --git a/crypto/src/crypto/IEntropySource.cs b/crypto/src/crypto/IEntropySource.cs
new file mode 100644
index 000000000..33ce1b801
--- /dev/null
+++ b/crypto/src/crypto/IEntropySource.cs
@@ -0,0 +1,29 @@
+using System;
+
+namespace Org.BouncyCastle.Crypto
+{
+	/// <summary>
+	/// Base interface describing an entropy source for a DRGB.
+	/// </summary>
+	public interface IEntropySource
+	{
+		/// <summary>
+		/// Return whether or not this entropy source is regarded as prediction resistant.
+		/// </summary>
+		/// <value><c>true</c> if this instance is prediction resistant; otherwise, <c>false</c>.</value>
+		bool IsPredictionResistant { get; }
+
+		/// <summary>
+		/// Return a byte array of entropy.
+		/// </summary>
+		/// <returns>The entropy bytes.</returns>
+		byte[] GetEntropy();
+
+		/// <summary>
+		/// Return the number of bits of entropy this source can produce.
+		/// </summary>
+		/// <value>The size, in bits, of the return value of getEntropy.</value>
+		int EntropySize { get; }
+	}
+}
+
diff --git a/crypto/src/crypto/IEntropySourceProvider.cs b/crypto/src/crypto/IEntropySourceProvider.cs
new file mode 100644
index 000000000..990c6497b
--- /dev/null
+++ b/crypto/src/crypto/IEntropySourceProvider.cs
@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Org.BouncyCastle.Crypto
+{
+    /// <summary>
+    /// Base interface describing a provider of entropy sources.
+    /// </summary>
+    public interface IEntropySourceProvider
+    {
+        /// <summary>
+        /// Return an entropy source providing a block of entropy.
+        /// </summary>
+        /// <param name="bitsRequired">The size of the block of entropy required.</param>
+        /// <returns>An entropy source providing bitsRequired blocks of entropy.</returns>
+        IEntropySource Get(int bitsRequired);
+    }
+}
diff --git a/crypto/src/crypto/prng/CtrSP800Drbg.cs b/crypto/src/crypto/prng/CtrSP800Drbg.cs
new file mode 100644
index 000000000..089cd17cd
--- /dev/null
+++ b/crypto/src/crypto/prng/CtrSP800Drbg.cs
@@ -0,0 +1,495 @@
+using System;
+
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Utilities.Encoders;
+
+namespace Org.BouncyCastle.Crypto.Prng.Drbg
+{
+	/**
+	 * A SP800-90A CTR DRBG.
+	 */
+	public class CtrSP800Drbg: SP80090Drbg
+	{
+	    private static readonly long       TDEA_RESEED_MAX = 1L << (32 - 1);
+		private static readonly long       AES_RESEED_MAX = 1L << (48 - 1);
+		private static readonly int        TDEA_MAX_BITS_REQUEST = 1 << (13 - 1);
+		private static readonly int        AES_MAX_BITS_REQUEST = 1 << (19 - 1);
+
+	    private IEntropySource        _entropySource;
+	    private IBlockCipher          _engine;
+	    private int                   _keySizeInBits;
+	    private int                   _seedLength;
+	    private int                   _securityStrength;
+
+	    // internal state
+	    private byte[]                _Key;
+	    private byte[]                _V;
+	    private long                  _reseedCounter = 0;
+	    private bool                  _isTDEA = false;
+
+	    /**
+	     * Construct a SP800-90A CTR DRBG.
+	     * <p>
+	     * Minimum entropy requirement is the security strength requested.
+	     * </p>
+	     * @param engine underlying block cipher to use to support DRBG
+	     * @param keySizeInBits size of the key to use with the block cipher.
+	     * @param securityStrength security strength required (in bits)
+	     * @param entropySource source of entropy to use for seeding/reseeding.
+	     * @param personalizationString personalization string to distinguish this DRBG (may be null).
+	     * @param nonce nonce to further distinguish this DRBG (may be null).
+	     */
+	    public CtrSP800Drbg(IBlockCipher engine, int keySizeInBits, int securityStrength, IEntropySource entropySource, byte[] personalizationString, byte[] nonce)
+	    {
+	        _entropySource = entropySource;
+	        _engine = engine;     
+	        
+	        _keySizeInBits = keySizeInBits;
+	        _securityStrength = securityStrength;
+	        _seedLength = keySizeInBits + engine.GetBlockSize() * 8;
+	        _isTDEA = isTDEA(engine);
+
+	        if (securityStrength > 256)
+	        {
+	            throw new ArgumentException("Requested security strength is not supported by the derivation function");
+	        }
+
+	        if (getMaxSecurityStrength(engine, keySizeInBits) < securityStrength)
+	        {
+	            throw new ArgumentException("Requested security strength is not supported by block cipher and key size");
+	        }
+
+	        if (entropySource.EntropySize < securityStrength)
+	        {
+	            throw new ArgumentException("Not enough entropy for security strength required");
+	        }
+
+	        byte[] entropy = getEntropy();  // Get_entropy_input
+
+	        CTR_DRBG_Instantiate_algorithm(entropy, nonce, personalizationString);
+	    }
+
+	    private void CTR_DRBG_Instantiate_algorithm(byte[] entropy, byte[] nonce,
+	            byte[] personalisationString)
+	    {
+	        byte[] seedMaterial = Arrays.Concatenate(entropy, nonce, personalisationString);
+	        byte[] seed = Block_Cipher_df(seedMaterial, _seedLength);
+
+	        int outlen = _engine.GetBlockSize();
+
+	        _Key = new byte[(_keySizeInBits + 7) / 8];
+	        _V = new byte[outlen];
+
+	         // _Key & _V are modified by this call
+	        CTR_DRBG_Update(seed, _Key, _V); 
+
+	        _reseedCounter = 1;
+	    }
+
+	    private void CTR_DRBG_Update(byte[] seed, byte[] key, byte[] v)
+	    {
+	        byte[] temp = new byte[seed.Length];
+	        byte[] outputBlock = new byte[_engine.GetBlockSize()];
+	        
+	        int i=0;
+	        int outLen = _engine.GetBlockSize();
+
+	        _engine.Init(true, new KeyParameter(expandKey(key)));
+	        while (i*outLen < seed.Length)
+	        {
+	            addOneTo(v);
+	            _engine.ProcessBlock(v, 0, outputBlock, 0);
+
+	            int bytesToCopy = ((temp.Length - i * outLen) > outLen)
+	                    ? outLen : (temp.Length - i * outLen);
+	            
+	            Array.Copy(outputBlock, 0, temp, i * outLen, bytesToCopy);
+	            ++i;
+	        }
+
+	        XOR(temp, seed, temp, 0);
+
+	        Array.Copy(temp, 0, key, 0, key.Length);
+	        Array.Copy(temp, key.Length, v, 0, v.Length);
+	    }
+	    
+	    private void CTR_DRBG_Reseed_algorithm(byte[] additionalInput)
+	    {
+	        byte[] seedMaterial = Arrays.Concatenate(getEntropy(), additionalInput);
+
+	        seedMaterial = Block_Cipher_df(seedMaterial, _seedLength);
+
+	        CTR_DRBG_Update(seedMaterial, _Key, _V);
+
+	        _reseedCounter = 1;
+	    }
+
+	    private void XOR(byte[] output, byte[] a, byte[] b, int bOff)
+	    {
+				for (int i=0; i< output.Length; i++) 
+	        {
+					output[i] = (byte)(a[i] ^ b[i+bOff]);
+	        }
+	    }
+	    
+	    private void addOneTo(byte[] longer)
+	    {
+	        int carry = 1;
+	        for (int i = 1; i <= longer.Length; i++) // warning
+	        {
+	            int res = (longer[longer.Length - i] & 0xff) + carry;
+	            carry = (res > 0xff) ? 1 : 0;
+	            longer[longer.Length - i] = (byte)res;
+	        }
+	    } 
+
+	    private byte[] getEntropy()
+	    {
+	        byte[] entropy = _entropySource.GetEntropy();
+	        if (entropy.Length < (_securityStrength + 7) / 8)
+	        {
+	            throw new InvalidOperationException("Insufficient entropy provided by entropy source");
+	        }
+	        return entropy;
+	    }
+
+	    // -- Internal state migration ---
+	    
+	    private static readonly byte[] K_BITS = Hex.Decode("000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F");
+
+	    // 1. If (number_of_bits_to_return > max_number_of_bits), then return an
+	    // ERROR_FLAG.
+	    // 2. L = len (input_string)/8.
+	    // 3. N = number_of_bits_to_return/8.
+	    // Comment: L is the bitstring represention of
+	    // the integer resulting from len (input_string)/8.
+	    // L shall be represented as a 32-bit integer.
+	    //
+	    // Comment : N is the bitstring represention of
+	    // the integer resulting from
+	    // number_of_bits_to_return/8. N shall be
+	    // represented as a 32-bit integer.
+	    //
+	    // 4. S = L || N || input_string || 0x80.
+	    // 5. While (len (S) mod outlen)
+	    // Comment : Pad S with zeros, if necessary.
+	    // 0, S = S || 0x00.
+	    //
+	    // Comment : Compute the starting value.
+	    // 6. temp = the Null string.
+	    // 7. i = 0.
+	    // 8. K = Leftmost keylen bits of 0x00010203...1D1E1F.
+	    // 9. While len (temp) < keylen + outlen, do
+	    //
+	    // IV = i || 0outlen - len (i).
+	    //
+	    // 9.1
+	    //
+	    // temp = temp || BCC (K, (IV || S)).
+	    //
+	    // 9.2
+	    //
+	    // i = i + 1.
+	    //
+	    // 9.3
+	    //
+	    // Comment : i shall be represented as a 32-bit
+	    // integer, i.e., len (i) = 32.
+	    //
+	    // Comment: The 32-bit integer represenation of
+	    // i is padded with zeros to outlen bits.
+	    //
+	    // Comment: Compute the requested number of
+	    // bits.
+	    //
+	    // 10. K = Leftmost keylen bits of temp.
+	    //
+	    // 11. X = Next outlen bits of temp.
+	    //
+	    // 12. temp = the Null string.
+	    //
+	    // 13. While len (temp) < number_of_bits_to_return, do
+	    //
+	    // 13.1 X = Block_Encrypt (K, X).
+	    //
+	    // 13.2 temp = temp || X.
+	    //
+	    // 14. requested_bits = Leftmost number_of_bits_to_return of temp.
+	    //
+	    // 15. Return SUCCESS and requested_bits.
+	    private byte[] Block_Cipher_df(byte[] inputString, int bitLength)
+	    {
+	        int outLen = _engine.GetBlockSize();
+	        int L = inputString.Length; // already in bytes
+	        int N = bitLength / 8;
+	        // 4 S = L || N || inputstring || 0x80
+	        int sLen = 4 + 4 + L + 1;
+	        int blockLen = ((sLen + outLen - 1) / outLen) * outLen;
+	        byte[] S = new byte[blockLen];
+	        copyIntToByteArray(S, L, 0);
+	        copyIntToByteArray(S, N, 4);
+	        Array.Copy(inputString, 0, S, 8, L);
+	        S[8 + L] = (byte)0x80;
+	        // S already padded with zeros
+
+	        byte[] temp = new byte[_keySizeInBits / 8 + outLen];
+	        byte[] bccOut = new byte[outLen];
+
+	        byte[] IV = new byte[outLen]; 
+	        
+	        int i = 0;
+	        byte[] K = new byte[_keySizeInBits / 8];
+	        Array.Copy(K_BITS, 0, K, 0, K.Length);
+
+	        while (i*outLen*8 < _keySizeInBits + outLen *8)
+	        {
+	            copyIntToByteArray(IV, i, 0);
+	            BCC(bccOut, K, IV, S);
+
+	            int bytesToCopy = ((temp.Length - i * outLen) > outLen)
+	                    ? outLen
+	                    : (temp.Length - i * outLen);
+	            
+	            Array.Copy(bccOut, 0, temp, i * outLen, bytesToCopy);
+	            ++i;
+	        }
+
+	        byte[] X = new byte[outLen];
+	        Array.Copy(temp, 0, K, 0, K.Length);
+	        Array.Copy(temp, K.Length, X, 0, X.Length);
+
+	        temp = new byte[bitLength / 2];
+
+	        i = 0;
+	        _engine.Init(true, new KeyParameter(expandKey(K)));
+
+	        while (i * outLen < temp.Length)
+	        {
+	            _engine.ProcessBlock(X, 0, X, 0);
+
+	            int bytesToCopy = ((temp.Length - i * outLen) > outLen)
+	                    ? outLen
+	                    : (temp.Length - i * outLen);
+
+	            Array.Copy(X, 0, temp, i * outLen, bytesToCopy);
+	            i++;
+	        }
+
+	        return temp;
+	    }
+
+	    /*
+	    * 1. chaining_value = 0^outlen    
+	    *    . Comment: Set the first chaining value to outlen zeros.
+	    * 2. n = len (data)/outlen.
+	    * 3. Starting with the leftmost bits of data, split the data into n blocks of outlen bits 
+	    *    each, forming block(1) to block(n). 
+	    * 4. For i = 1 to n do
+	    * 4.1 input_block = chaining_value ^ block(i) .
+	    * 4.2 chaining_value = Block_Encrypt (Key, input_block).
+	    * 5. output_block = chaining_value.
+	    * 6. Return output_block. 
+	     */
+	    private void BCC(byte[] bccOut, byte[] k, byte[] iV, byte[] data)
+	    {
+	        int outlen = _engine.GetBlockSize();
+	        byte[] chainingValue = new byte[outlen]; // initial values = 0
+	        int n = data.Length / outlen;
+
+	        byte[] inputBlock = new byte[outlen];
+
+	        _engine.Init(true, new KeyParameter(expandKey(k)));
+
+	        _engine.ProcessBlock(iV, 0, chainingValue, 0);
+
+	        for (int i = 0; i < n; i++)
+	        {
+	            XOR(inputBlock, chainingValue, data, i*outlen);
+	            _engine.ProcessBlock(inputBlock, 0, chainingValue, 0);
+	        }
+
+	        Array.Copy(chainingValue, 0, bccOut, 0, bccOut.Length);
+	    }
+
+	    private void copyIntToByteArray(byte[] buf, int value, int offSet)
+	    {
+	        buf[offSet + 0] = ((byte)(value >> 24));
+	        buf[offSet + 1] = ((byte)(value >> 16));
+	        buf[offSet + 2] = ((byte)(value >> 8));
+	        buf[offSet + 3] = ((byte)(value));
+	    }
+
+	    /**
+	     * Return the block size (in bits) of the DRBG.
+	     *
+	     * @return the number of bits produced on each internal round of the DRBG.
+	     */
+	    public int BlockSize
+	    {
+			get {
+				return _V.Length * 8;
+			}
+	    }
+
+	    /**
+	     * Populate a passed in array with random data.
+	     *
+	     * @param output output array for generated bits.
+	     * @param additionalInput additional input to be added to the DRBG in this step.
+	     * @param predictionResistant true if a reseed should be forced, false otherwise.
+	     *
+	     * @return number of bits generated, -1 if a reseed required.
+	     */
+	    public int Generate(byte[] output, byte[] additionalInput, bool predictionResistant)
+	    {
+	        if (_isTDEA)
+	        {
+	            if (_reseedCounter > TDEA_RESEED_MAX)
+	            {
+	                return -1;
+	            }
+
+	            if (Utils.isTooLarge(output, TDEA_MAX_BITS_REQUEST / 8))
+	            {
+	                throw new ArgumentException("Number of bits per request limited to " + TDEA_MAX_BITS_REQUEST);
+	            }
+	        }
+	        else
+	        {
+	            if (_reseedCounter > AES_RESEED_MAX)
+	            {
+	                return -1;
+	            }
+
+	            if (Utils.isTooLarge(output, AES_MAX_BITS_REQUEST / 8))
+	            {
+	                throw new ArgumentException("Number of bits per request limited to " + AES_MAX_BITS_REQUEST);
+	            }
+	        }
+
+	        if (predictionResistant)
+	        {
+	            CTR_DRBG_Reseed_algorithm(additionalInput);
+	            additionalInput = null;
+	        }
+
+	        if (additionalInput != null)
+	        {
+	            additionalInput = Block_Cipher_df(additionalInput, _seedLength);
+	            CTR_DRBG_Update(additionalInput, _Key, _V);
+	        }
+	        else
+	        {
+	            additionalInput = new byte[_seedLength];
+	        }
+
+	        byte[] tmp = new byte[_V.Length];
+
+	        _engine.Init(true, new KeyParameter(expandKey(_Key)));
+
+				for (int i = 0; i <= output.Length / tmp.Length; i++)
+	        {
+					int bytesToCopy = ((output.Length - i * tmp.Length) > tmp.Length)
+						? tmp.Length
+	                    : (output.Length - i * _V.Length);
+
+	            if (bytesToCopy != 0)
+	            {
+	                addOneTo(_V);
+
+						_engine.ProcessBlock(_V, 0, tmp, 0);
+
+						Array.Copy(tmp, 0, output, i * tmp.Length, bytesToCopy);
+	            }
+	        }
+
+	        CTR_DRBG_Update(additionalInput, _Key, _V);
+
+	        _reseedCounter++;
+
+	        return output.Length * 8;
+	    }
+
+	    /**
+	      * Reseed the DRBG.
+	      *
+	      * @param additionalInput additional input to be added to the DRBG in this step.
+	      */
+	    public void Reseed(byte[] additionalInput)
+	    {
+	        CTR_DRBG_Reseed_algorithm(additionalInput);
+	    }
+
+	    private bool isTDEA(IBlockCipher cipher)
+	    {
+	        return cipher.AlgorithmName.Equals("DESede") || cipher.AlgorithmName.Equals("TDEA");
+	    }
+
+	    private int getMaxSecurityStrength(IBlockCipher cipher, int keySizeInBits)
+	    {
+	        if (isTDEA(cipher) && keySizeInBits == 168)
+	        {
+	            return 112;
+	        }
+	        if (cipher.AlgorithmName.Equals("AES"))
+	        {
+	            return keySizeInBits;
+	        }
+
+	        return -1;
+	    }
+
+	    byte[] expandKey(byte[] key)
+	    {
+	        if (_isTDEA)
+	        {
+	            // expand key to 192 bits.
+	            byte[] tmp = new byte[24];
+
+	            padKey(key, 0, tmp, 0);
+	            padKey(key, 7, tmp, 8);
+	            padKey(key, 14, tmp, 16);
+
+	            return tmp;
+	        }
+	        else
+	        {
+	            return key;
+	        }
+	    }
+
+	    /**
+	     * Pad out a key for TDEA, setting odd parity for each byte.
+	     *
+	     * @param keyMaster
+	     * @param keyOff
+	     * @param tmp
+	     * @param tmpOff
+	     */
+	    private void padKey(byte[] keyMaster, int keyOff, byte[] tmp, int tmpOff)
+	    {
+	        tmp[tmpOff + 0] = (byte)(keyMaster[keyOff + 0] & 0xfe);
+	        tmp[tmpOff + 1] = (byte)((keyMaster[keyOff + 0] << 7) | ((keyMaster[keyOff + 1] & 0xfc) >> 1));
+	        tmp[tmpOff + 2] = (byte)((keyMaster[keyOff + 1] << 6) | ((keyMaster[keyOff + 2] & 0xf8) >> 2));
+	        tmp[tmpOff + 3] = (byte)((keyMaster[keyOff + 2] << 5) | ((keyMaster[keyOff + 3] & 0xf0) >> 3));
+	        tmp[tmpOff + 4] = (byte)((keyMaster[keyOff + 3] << 4) | ((keyMaster[keyOff + 4] & 0xe0) >> 4));
+	        tmp[tmpOff + 5] = (byte)((keyMaster[keyOff + 4] << 3) | ((keyMaster[keyOff + 5] & 0xc0) >> 5));
+	        tmp[tmpOff + 6] = (byte)((keyMaster[keyOff + 5] << 2) | ((keyMaster[keyOff + 6] & 0x80) >> 6));
+	        tmp[tmpOff + 7] = (byte)(keyMaster[keyOff + 6] << 1);
+
+	        for (int i = tmpOff; i <= tmpOff + 7; i++)
+	        {
+	            int b = tmp[i];
+	            tmp[i] = (byte)((b & 0xfe) |
+	                            ((((b >> 1) ^
+	                            (b >> 2) ^
+	                            (b >> 3) ^
+	                            (b >> 4) ^
+	                            (b >> 5) ^
+	                            (b >> 6) ^
+	                            (b >> 7)) ^ 0x01) & 0x01));
+	        }
+	    }
+	}
+}
diff --git a/crypto/src/crypto/prng/HMacSP800Drbg.cs b/crypto/src/crypto/prng/HMacSP800Drbg.cs
new file mode 100644
index 000000000..b2903766f
--- /dev/null
+++ b/crypto/src/crypto/prng/HMacSP800Drbg.cs
@@ -0,0 +1,196 @@
+using System;
+
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Prng.Drbg
+{
+	/**
+	 * A SP800-90A HMAC DRBG.
+	 */
+	public class HMacSP800Drbg: SP80090Drbg
+	{
+	    private readonly static long       RESEED_MAX = 1L << (48 - 1);
+		private readonly static int        MAX_BITS_REQUEST = 1 << (19 - 1);
+
+	    private byte[] _K;
+	    private byte[] _V;
+	    private long   _reseedCounter;
+	    private IEntropySource _entropySource;
+	    private IMac _hMac;
+	    private int _securityStrength;
+
+	    /**
+	     * Construct a SP800-90A Hash DRBG.
+	     * <p>
+	     * Minimum entropy requirement is the security strength requested.
+	     * </p>
+	     * @param hMac Hash MAC to base the DRBG on.
+	     * @param securityStrength security strength required (in bits)
+	     * @param entropySource source of entropy to use for seeding/reseeding.
+	     * @param personalizationString personalization string to distinguish this DRBG (may be null).
+	     * @param nonce nonce to further distinguish this DRBG (may be null).
+	     */
+	    public HMacSP800Drbg(IMac hMac, int securityStrength, IEntropySource entropySource, byte[] personalizationString, byte[] nonce)
+	    {
+	        if (securityStrength > Utils.getMaxSecurityStrength(hMac))
+	        {
+	            throw new ArgumentException("Requested security strength is not supported by the derivation function");
+	        }
+
+	        if (entropySource.EntropySize < securityStrength)
+	        {
+	            throw new ArgumentException("Not enough entropy for security strength required");
+	        }
+
+	        _securityStrength = securityStrength;
+	        _entropySource = entropySource;
+	        _hMac = hMac;
+
+	        byte[] entropy = getEntropy();
+	        byte[] seedMaterial = Arrays.Concatenate(entropy, nonce, personalizationString);
+
+	        _K = new byte[hMac.GetMacSize()];
+	        _V = new byte[_K.Length];
+	        Arrays.Fill(_V, (byte)1);
+
+	        hmac_DRBG_Update(seedMaterial);
+
+	        _reseedCounter = 1;
+	    }
+
+	    private void hmac_DRBG_Update(byte[] seedMaterial)
+	    {
+	        hmac_DRBG_Update_Func(seedMaterial, (byte)0x00);
+	        if (seedMaterial != null)
+	        {
+	            hmac_DRBG_Update_Func(seedMaterial, (byte)0x01);
+	        }
+	    }
+
+	    private void hmac_DRBG_Update_Func(byte[] seedMaterial, byte vValue)
+	    {
+	        _hMac.Init(new KeyParameter(_K));
+
+	        _hMac.BlockUpdate(_V, 0, _V.Length);
+	        _hMac.Update(vValue);
+
+	        if (seedMaterial != null)
+	        {
+	            _hMac.BlockUpdate(seedMaterial, 0, seedMaterial.Length);
+	        }
+
+	        _hMac.DoFinal(_K, 0);
+
+	        _hMac.Init(new KeyParameter(_K));
+	        _hMac.BlockUpdate(_V, 0, _V.Length);
+
+	        _hMac.DoFinal(_V, 0);
+	    }
+
+	    /**
+	     * Return the block size (in bits) of the DRBG.
+	     *
+	     * @return the number of bits produced on each round of the DRBG.
+	     */
+	    public int BlockSize
+	    {
+			get {
+				return _V.Length * 8;
+			}
+	    }
+
+	    /**
+	     * Populate a passed in array with random data.
+	     *
+	     * @param output output array for generated bits.
+	     * @param additionalInput additional input to be added to the DRBG in this step.
+	     * @param predictionResistant true if a reseed should be forced, false otherwise.
+	     *
+	     * @return number of bits generated, -1 if a reseed required.
+	     */
+	    public int Generate(byte[] output, byte[] additionalInput, bool predictionResistant)
+	    {
+	        int numberOfBits = output.Length * 8;
+
+	        if (numberOfBits > MAX_BITS_REQUEST)
+	        {
+	            throw new ArgumentException("Number of bits per request limited to " + MAX_BITS_REQUEST);
+	        }
+
+	        if (_reseedCounter > RESEED_MAX)
+	        {
+	            return -1;
+	        }
+
+	        if (predictionResistant)
+	        {
+	            Reseed(additionalInput);
+	            additionalInput = null;
+	        }
+
+	        // 2.
+	        if (additionalInput != null)
+	        {
+	            hmac_DRBG_Update(additionalInput);
+	        }
+
+	        // 3.
+	        byte[] rv = new byte[output.Length];
+
+	        int m = output.Length / _V.Length;
+
+	        _hMac.Init(new KeyParameter(_K));
+
+	        for (int i = 0; i < m; i++)
+	        {
+	            _hMac.BlockUpdate(_V, 0, _V.Length);
+	            _hMac.DoFinal(_V, 0);
+
+	            Array.Copy(_V, 0, rv, i * _V.Length, _V.Length);
+	        }
+
+	        if (m * _V.Length < rv.Length)
+	        {
+					_hMac.BlockUpdate(_V, 0, _V.Length);
+	            _hMac.DoFinal(_V, 0);
+
+	            Array.Copy(_V, 0, rv, m * _V.Length, rv.Length - (m * _V.Length));
+	        }
+
+	        hmac_DRBG_Update(additionalInput);
+
+	        _reseedCounter++;
+
+	        Array.Copy(rv, 0, output, 0, output.Length);
+
+	        return numberOfBits;
+	    }
+
+	    /**
+	      * Reseed the DRBG.
+	      *
+	      * @param additionalInput additional input to be added to the DRBG in this step.
+	      */
+	    public void Reseed(byte[] additionalInput)
+	    {
+	        byte[] entropy = getEntropy();
+	        byte[] seedMaterial = Arrays.Concatenate(entropy, additionalInput);
+
+	        hmac_DRBG_Update(seedMaterial);
+
+	        _reseedCounter = 1;
+	    }
+
+	    private byte[] getEntropy()
+	    {
+	        byte[] entropy = _entropySource.GetEntropy();
+
+	        if (entropy.Length < (_securityStrength + 7) / 8)
+	        {
+	            throw new InvalidOperationException("Insufficient entropy provided by entropy source");
+	        }
+	        return entropy;
+	    }
+	}
+}
diff --git a/crypto/src/crypto/prng/HashSP800Drbg.cs b/crypto/src/crypto/prng/HashSP800Drbg.cs
new file mode 100644
index 000000000..b2b386f17
--- /dev/null
+++ b/crypto/src/crypto/prng/HashSP800Drbg.cs
@@ -0,0 +1,295 @@
+using System;
+using System.Collections;
+
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Prng.Drbg
+{
+	/**
+	 * A SP800-90A Hash DRBG.
+	 */
+	public class HashSP800Drbg: SP80090Drbg
+	{
+	    private readonly static byte[]     ONE = { 0x01 };
+
+		private readonly static long       RESEED_MAX = 1L << (48 - 1);
+		private readonly static int        MAX_BITS_REQUEST = 1 << (19 - 1);
+
+		private static readonly IDictionary seedlens = Platform.CreateHashtable();
+
+		static HashSP800Drbg()
+	    {
+				seedlens.Add("SHA-1", 440);
+				seedlens.Add("SHA-224", 440);
+				seedlens.Add("SHA-256", 440);
+				seedlens.Add("SHA-512/256", 440);
+				seedlens.Add("SHA-512/224", 440);
+				seedlens.Add("SHA-384", 888);
+				seedlens.Add("SHA-512", 888);
+
+	    }
+
+	    private IDigest        _digest;
+	    private byte[]         _V;
+	    private byte[]         _C;
+	    private long           _reseedCounter;
+	    private IEntropySource _entropySource;
+	    private int            _securityStrength;
+	    private int            _seedLength;
+
+	    /**
+	     * Construct a SP800-90A Hash DRBG.
+	     * <p>
+	     * Minimum entropy requirement is the security strength requested.
+	     * </p>
+	     * @param digest  source digest to use for DRB stream.
+	     * @param securityStrength security strength required (in bits)
+	     * @param entropySource source of entropy to use for seeding/reseeding.
+	     * @param personalizationString personalization string to distinguish this DRBG (may be null).
+	     * @param nonce nonce to further distinguish this DRBG (may be null).
+	     */
+	    public HashSP800Drbg(IDigest digest, int securityStrength, IEntropySource entropySource, byte[] personalizationString, byte[] nonce)
+	    {
+	        if (securityStrength > Utils.getMaxSecurityStrength(digest))
+	        {
+	            throw new ArgumentException("Requested security strength is not supported by the derivation function");
+	        }
+
+	        if (entropySource.EntropySize < securityStrength)
+	        {
+	            throw new ArgumentException("Not enough entropy for security strength required");
+	        }
+
+	        _digest = digest;
+	        _entropySource = entropySource;
+	        _securityStrength = securityStrength;
+	        _seedLength = (int)seedlens[digest.AlgorithmName];
+
+	        // 1. seed_material = entropy_input || nonce || personalization_string.
+	        // 2. seed = Hash_df (seed_material, seedlen).
+	        // 3. V = seed.
+	        // 4. C = Hash_df ((0x00 || V), seedlen). Comment: Preceed V with a byte
+	        // of zeros.
+	        // 5. reseed_counter = 1.
+	        // 6. Return V, C, and reseed_counter as the initial_working_state
+
+	        byte[] entropy = getEntropy();
+	        byte[] seedMaterial = Arrays.Concatenate(entropy, nonce, personalizationString);
+	        byte[] seed = Utils.hash_df(_digest, seedMaterial, _seedLength);
+
+	        _V = seed;
+	        byte[] subV = new byte[_V.Length + 1];
+	        Array.Copy(_V, 0, subV, 1, _V.Length);
+	        _C = Utils.hash_df(_digest, subV, _seedLength);
+
+	        _reseedCounter = 1;
+	    }
+
+	    /**
+	     * Return the block size (in bits) of the DRBG.
+	     *
+	     * @return the number of bits produced on each internal round of the DRBG.
+	     */
+	    public int BlockSize
+	    {
+			get {
+				return _digest.GetDigestSize () * 8;
+			}
+	    }
+
+	    /**
+	     * Populate a passed in array with random data.
+	     *
+	     * @param output output array for generated bits.
+	     * @param additionalInput additional input to be added to the DRBG in this step.
+	     * @param predictionResistant true if a reseed should be forced, false otherwise.
+	     *
+	     * @return number of bits generated, -1 if a reseed required.
+	     */
+	    public int Generate(byte[] output, byte[] additionalInput, bool predictionResistant)
+	    {
+	        // 1. If reseed_counter > reseed_interval, then return an indication that a
+	        // reseed is required.
+	        // 2. If (additional_input != Null), then do
+	        // 2.1 w = Hash (0x02 || V || additional_input).
+	        // 2.2 V = (V + w) mod 2^seedlen
+	        // .
+	        // 3. (returned_bits) = Hashgen (requested_number_of_bits, V).
+	        // 4. H = Hash (0x03 || V).
+	        // 5. V = (V + H + C + reseed_counter) mod 2^seedlen
+	        // .
+	        // 6. reseed_counter = reseed_counter + 1.
+	        // 7. Return SUCCESS, returned_bits, and the new values of V, C, and
+	        // reseed_counter for the new_working_state.
+	        int numberOfBits = output.Length*8;
+
+	        if (numberOfBits > MAX_BITS_REQUEST)
+	        {
+	            throw new ArgumentException("Number of bits per request limited to " + MAX_BITS_REQUEST);
+	        }
+
+	        if (_reseedCounter > RESEED_MAX)
+	        {
+	            return -1;
+	        }
+
+	        if (predictionResistant)
+	        {   
+	            Reseed(additionalInput);
+	            additionalInput = null;
+	        }
+
+	        // 2.
+	        if (additionalInput != null)
+	        {
+	            byte[] newInput = new byte[1 + _V.Length + additionalInput.Length];
+	            newInput[0] = 0x02;
+	            Array.Copy(_V, 0, newInput, 1, _V.Length);
+	            // TODO: inOff / inLength
+	            Array.Copy(additionalInput, 0, newInput, 1 + _V.Length, additionalInput.Length);
+	            byte[] w = hash(newInput);
+
+	            addTo(_V, w);
+	        }
+	        
+	        // 3.
+	        byte[] rv = hashgen(_V, numberOfBits);
+	        
+	        // 4.
+	        byte[] subH = new byte[_V.Length + 1];
+	        Array.Copy(_V, 0, subH, 1, _V.Length);
+	        subH[0] = 0x03;
+	        
+	        byte[] H = hash(subH);
+	        
+	        // 5.
+	        addTo(_V, H);
+	        addTo(_V, _C);
+	        byte[] c = new byte[4];
+	        c[0] = (byte)(_reseedCounter >> 24);
+	        c[1] = (byte)(_reseedCounter >> 16);
+	        c[2] = (byte)(_reseedCounter >> 8);
+	        c[3] = (byte)_reseedCounter;
+	        
+	        addTo(_V, c);
+
+	        _reseedCounter++;
+
+	        Array.Copy(rv, 0, output, 0, output.Length);
+
+	        return numberOfBits;
+	    }
+
+	    private byte[] getEntropy()
+	    {
+	        byte[] entropy = _entropySource.GetEntropy();
+	        if (entropy.Length < (_securityStrength + 7) / 8)
+	        {
+	            throw new InvalidOperationException("Insufficient entropy provided by entropy source");
+	        }
+	        return entropy;
+	    }
+
+	    // this will always add the shorter length byte array mathematically to the
+	    // longer length byte array.
+	    // be careful....
+	    private void addTo(byte[] longer, byte[] shorter)
+	    {
+	        int carry = 0;
+	        for (int i=1;i <= shorter.Length; i++) // warning
+	        {
+	            int res = (longer[longer.Length-i] & 0xff) + (shorter[shorter.Length-i] & 0xff) + carry;
+	            carry = (res > 0xff) ? 1 : 0;
+	            longer[longer.Length-i] = (byte)res;
+	        }
+	        
+	        for (int i=shorter.Length+1;i <= longer.Length; i++) // warning
+	        {
+	            int res = (longer[longer.Length-i] & 0xff) + carry;
+	            carry = (res > 0xff) ? 1 : 0;
+	            longer[longer.Length-i] = (byte)res;
+	        }
+	    }
+
+	    /**
+	      * Reseed the DRBG.
+	      *
+	      * @param additionalInput additional input to be added to the DRBG in this step.
+	      */
+	    public void Reseed(byte[] additionalInput)
+	    {
+	        // 1. seed_material = 0x01 || V || entropy_input || additional_input.
+	        //
+	        // 2. seed = Hash_df (seed_material, seedlen).
+	        //
+	        // 3. V = seed.
+	        //
+	        // 4. C = Hash_df ((0x00 || V), seedlen).
+	        //
+	        // 5. reseed_counter = 1.
+	        //
+	        // 6. Return V, C, and reseed_counter for the new_working_state.
+	        //
+	        // Comment: Precede with a byte of all zeros.
+	        byte[] entropy = getEntropy();
+	        byte[] seedMaterial = Arrays.Concatenate(ONE, _V, entropy, additionalInput);
+	        byte[] seed = Utils.hash_df(_digest, seedMaterial, _seedLength);
+
+	        _V = seed;
+	        byte[] subV = new byte[_V.Length + 1];
+	        subV[0] = 0x00;
+	        Array.Copy(_V, 0, subV, 1, _V.Length);
+	        _C = Utils.hash_df(_digest, subV, _seedLength);
+
+	        _reseedCounter = 1;
+	    }
+	    
+	    private byte[] hash(byte[] input)
+	    {
+	        byte[] hash = new byte[_digest.GetDigestSize()];
+	        doHash(input, hash);
+	        return hash;
+	    }
+
+	    private void doHash(byte[] input, byte[] output)
+	    {
+	        _digest.BlockUpdate(input, 0, input.Length);
+	        _digest.DoFinal(output, 0);
+	    }
+
+	    // 1. m = [requested_number_of_bits / outlen]
+	    // 2. data = V.
+	    // 3. W = the Null string.
+	    // 4. For i = 1 to m
+	    // 4.1 wi = Hash (data).
+	    // 4.2 W = W || wi.
+	    // 4.3 data = (data + 1) mod 2^seedlen
+	    // .
+	    // 5. returned_bits = Leftmost (requested_no_of_bits) bits of W.
+	    private byte[] hashgen(byte[] input, int lengthInBits)
+	    {
+	        int digestSize = _digest.GetDigestSize();
+	        int m = (lengthInBits / 8) / digestSize;
+
+	        byte[] data = new byte[input.Length];
+	        Array.Copy(input, 0, data, 0, input.Length);
+
+	        byte[] W = new byte[lengthInBits / 8];
+
+	        byte[] dig = new byte[_digest.GetDigestSize()];
+	        for (int i = 0; i <= m; i++)
+	        {
+	            doHash(data, dig);
+
+	            int bytesToCopy = ((W.Length - i * dig.Length) > dig.Length)
+	                    ? dig.Length
+	                    : (W.Length - i * dig.Length);
+	            Array.Copy(dig, 0, W, i * dig.Length, bytesToCopy);
+
+	            addTo(data, ONE);
+	        }
+
+	        return W;
+	    }    
+	}
+}
diff --git a/crypto/src/crypto/prng/SP80090Drbg.cs b/crypto/src/crypto/prng/SP80090Drbg.cs
new file mode 100644
index 000000000..c39cf365f
--- /dev/null
+++ b/crypto/src/crypto/prng/SP80090Drbg.cs
@@ -0,0 +1,33 @@
+namespace Org.BouncyCastle.Crypto.Prng.Drbg
+{
+	/**
+	 * Interface to SP800-90A deterministic random bit generators.
+	 */
+	public interface SP80090Drbg
+	{
+	    /**
+	     * Return the block size of the DRBG.
+	     *
+	     * @return the block size (in bits) produced by each round of the DRBG.
+	     */
+		int BlockSize { get; }
+
+	    /**
+	     * Populate a passed in array with random data.
+	     *
+	     * @param output output array for generated bits.
+	     * @param additionalInput additional input to be added to the DRBG in this step.
+	     * @param predictionResistant true if a reseed should be forced, false otherwise.
+	     *
+	     * @return number of bits generated, -1 if a reseed required.
+	     */
+	    int Generate(byte[] output, byte[] additionalInput, bool predictionResistant);
+
+	    /**
+	     * Reseed the DRBG.
+	     *
+	     * @param additionalInput additional input to be added to the DRBG in this step.
+	     */
+	    void Reseed(byte[] additionalInput);
+	}
+}
diff --git a/crypto/src/crypto/prng/Utils.cs b/crypto/src/crypto/prng/Utils.cs
new file mode 100644
index 000000000..e5fe7d4b2
--- /dev/null
+++ b/crypto/src/crypto/prng/Utils.cs
@@ -0,0 +1,103 @@
+using System;
+using System.Collections;
+
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Prng.Drbg
+{
+	internal class Utils
+	{
+		private static readonly IDictionary maxSecurityStrengths = Platform.CreateHashtable();
+
+		static Utils()
+	    {
+	        maxSecurityStrengths.Add("SHA-1", 128);
+
+	        maxSecurityStrengths.Add("SHA-224", 192);
+	        maxSecurityStrengths.Add("SHA-256", 256);
+	        maxSecurityStrengths.Add("SHA-384", 256);
+	        maxSecurityStrengths.Add("SHA-512", 256);
+
+	        maxSecurityStrengths.Add("SHA-512/224", 192);
+	        maxSecurityStrengths.Add("SHA-512/256", 256);
+	    }
+
+	    internal static int getMaxSecurityStrength(IDigest d)
+	    {
+	        return (int)maxSecurityStrengths[d.AlgorithmName];
+	    }
+
+		internal static int getMaxSecurityStrength(IMac m)
+	    {
+	        string name = m.AlgorithmName;
+
+	        return (int)maxSecurityStrengths[name.Substring(0, name.IndexOf("/"))];
+	    }
+
+	    /**
+	     * Used by both Dual EC and Hash.
+	     */
+	    internal static byte[] hash_df(IDigest digest, byte[] seedMaterial, int seedLength)
+	    {
+	         // 1. temp = the Null string.
+	        // 2. .
+	        // 3. counter = an 8-bit binary value representing the integer "1".
+	        // 4. For i = 1 to len do
+	        // Comment : In step 4.1, no_of_bits_to_return
+	        // is used as a 32-bit string.
+	        // 4.1 temp = temp || Hash (counter || no_of_bits_to_return ||
+	        // input_string).
+	        // 4.2 counter = counter + 1.
+	        // 5. requested_bits = Leftmost (no_of_bits_to_return) of temp.
+	        // 6. Return SUCCESS and requested_bits.
+	        byte[] temp = new byte[(seedLength + 7) / 8];
+
+	        int len = temp.Length / digest.GetDigestSize();
+	        int counter = 1;
+
+	        byte[] dig = new byte[digest.GetDigestSize()];
+
+	        for (int i = 0; i <= len; i++)
+	        {
+	            digest.Update((byte)counter);
+
+	            digest.Update((byte)(seedLength >> 24));
+	            digest.Update((byte)(seedLength >> 16));
+	            digest.Update((byte)(seedLength >> 8));
+	            digest.Update((byte)seedLength);
+
+	            digest.BlockUpdate(seedMaterial, 0, seedMaterial.Length);
+
+	            digest.DoFinal(dig, 0);
+
+	            int bytesToCopy = ((temp.Length - i * dig.Length) > dig.Length)
+	                    ? dig.Length
+	                    : (temp.Length - i * dig.Length);
+	            Array.Copy(dig, 0, temp, i * dig.Length, bytesToCopy);
+
+	            counter++;
+	        }
+
+	        // do a left shift to get rid of excess bits.
+	        if (seedLength % 8 != 0)
+	        {
+	            int shift = 8 - (seedLength % 8);
+                uint carry = 0;
+
+	            for (int i = 0; i != temp.Length; i++)
+	            {
+	                uint b = (uint)(temp[i] & 0xff);
+	                temp[i] = (byte)((b >> shift) | (carry << (8 - shift)));
+	                carry = b;
+	            }
+	        }
+
+	        return temp;
+	    }
+
+	    internal static bool isTooLarge(byte[] bytes, int maxBytes)
+	    {
+	        return bytes != null && bytes.Length > maxBytes;
+	    }
+	}
+}
diff --git a/crypto/src/crypto/prng/drbg/CtrSP800Drbg.cs b/crypto/src/crypto/prng/drbg/CtrSP800Drbg.cs
new file mode 100644
index 000000000..d9595d530
--- /dev/null
+++ b/crypto/src/crypto/prng/drbg/CtrSP800Drbg.cs
@@ -0,0 +1,494 @@
+using System;
+
+using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Utilities.Encoders;
+
+namespace Org.BouncyCastle.Crypto.Prng.Drbg
+{
+	/**
+	 * A SP800-90A CTR DRBG.
+	 */
+	public class CTRSP800Drbg: SP80090Drbg
+	{
+	    private static readonly long       TDEA_RESEED_MAX = 1L << (32 - 1);
+		private static readonly long       AES_RESEED_MAX = 1L << (48 - 1);
+		private static readonly int        TDEA_MAX_BITS_REQUEST = 1 << (13 - 1);
+		private static readonly int        AES_MAX_BITS_REQUEST = 1 << (19 - 1);
+
+	    private IEntropySource        _entropySource;
+	    private IBlockCipher          _engine;
+	    private int                   _keySizeInBits;
+	    private int                   _seedLength;
+	    private int                   _securityStrength;
+
+	    // internal state
+	    private byte[]                _Key;
+	    private byte[]                _V;
+	    private long                  _reseedCounter = 0;
+	    private bool                  _isTDEA = false;
+
+	    /**
+	     * Construct a SP800-90A CTR DRBG.
+	     * <p>
+	     * Minimum entropy requirement is the security strength requested.
+	     * </p>
+	     * @param engine underlying block cipher to use to support DRBG
+	     * @param keySizeInBits size of the key to use with the block cipher.
+	     * @param securityStrength security strength required (in bits)
+	     * @param entropySource source of entropy to use for seeding/reseeding.
+	     * @param personalizationString personalization string to distinguish this DRBG (may be null).
+	     * @param nonce nonce to further distinguish this DRBG (may be null).
+	     */
+	    public CTRSP800Drbg(IBlockCipher engine, int keySizeInBits, int securityStrength, IEntropySource entropySource, byte[] personalizationString, byte[] nonce)
+	    {
+	        _entropySource = entropySource;
+	        _engine = engine;     
+	        
+	        _keySizeInBits = keySizeInBits;
+	        _securityStrength = securityStrength;
+	        _seedLength = keySizeInBits + engine.getBlockSize() * 8;
+	        _isTDEA = isTDEA(engine);
+
+	        if (securityStrength > 256)
+	        {
+	            throw new ArgumentException("Requested security strength is not supported by the derivation function");
+	        }
+
+	        if (getMaxSecurityStrength(engine, keySizeInBits) < securityStrength)
+	        {
+	            throw new ArgumentException("Requested security strength is not supported by block cipher and key size");
+	        }
+
+	        if (entropySource.EntropySize < securityStrength)
+	        {
+	            throw new ArgumentException("Not enough entropy for security strength required");
+	        }
+
+	        byte[] entropy = getEntropy();  // Get_entropy_input
+
+	        CTR_DRBG_Instantiate_algorithm(entropy, nonce, personalizationString);
+	    }
+
+	    private void CTR_DRBG_Instantiate_algorithm(byte[] entropy, byte[] nonce,
+	            byte[] personalisationString)
+	    {
+	        byte[] seedMaterial = Arrays.Concatenate(entropy, nonce, personalisationString);
+	        byte[] seed = Block_Cipher_df(seedMaterial, _seedLength);
+
+	        int outlen = _engine.getBlockSize();
+
+	        _Key = new byte[(_keySizeInBits + 7) / 8];
+	        _V = new byte[outlen];
+
+	         // _Key & _V are modified by this call
+	        CTR_DRBG_Update(seed, _Key, _V); 
+
+	        _reseedCounter = 1;
+	    }
+
+	    private void CTR_DRBG_Update(byte[] seed, byte[] key, byte[] v)
+	    {
+	        byte[] temp = new byte[seed.Length];
+	        byte[] outputBlock = new byte[_engine.getBlockSize()];
+	        
+	        int i=0;
+	        int outLen = _engine.getBlockSize();
+
+	        _engine.init(true, new KeyParameter(expandKey(key)));
+	        while (i*outLen < seed.Length)
+	        {
+	            addOneTo(v);
+	            _engine.processBlock(v, 0, outputBlock, 0);
+
+	            int bytesToCopy = ((temp.Length - i * outLen) > outLen)
+	                    ? outLen : (temp.Length - i * outLen);
+	            
+	            Array.Copy(outputBlock, 0, temp, i * outLen, bytesToCopy);
+	            ++i;
+	        }
+
+	        XOR(temp, seed, temp, 0);
+
+	        Array.Copy(temp, 0, key, 0, key.Length);
+	        Array.Copy(temp, key.Length, v, 0, v.Length);
+	    }
+	    
+	    private void CTR_DRBG_Reseed_algorithm(byte[] additionalInput)
+	    {
+	        byte[] seedMaterial = Arrays.Concatenate(getEntropy(), additionalInput);
+
+	        seedMaterial = Block_Cipher_df(seedMaterial, _seedLength);
+
+	        CTR_DRBG_Update(seedMaterial, _Key, _V);
+
+	        _reseedCounter = 1;
+	    }
+
+	    private void XOR(byte[] output, byte[] a, byte[] b, int bOff)
+	    {
+				for (int i=0; i< output.Length; i++) 
+	        {
+					output[i] = (byte)(a[i] ^ b[i+bOff]);
+	        }
+	    }
+	    
+	    private void addOneTo(byte[] longer)
+	    {
+	        int carry = 1;
+	        for (int i = 1; i <= longer.Length; i++) // warning
+	        {
+	            int res = (longer[longer.Length - i] & 0xff) + carry;
+	            carry = (res > 0xff) ? 1 : 0;
+	            longer[longer.Length - i] = (byte)res;
+	        }
+	    } 
+
+	    private byte[] getEntropy()
+	    {
+	        byte[] entropy = _entropySource.getEntropy();
+	        if (entropy.Length < (_securityStrength + 7) / 8)
+	        {
+	            throw new IllegalStateException("Insufficient entropy provided by entropy source");
+	        }
+	        return entropy;
+	    }
+
+	    // -- Internal state migration ---
+	    
+	    private static final byte[] K_BITS = Hex.decode("000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F");
+
+	    // 1. If (number_of_bits_to_return > max_number_of_bits), then return an
+	    // ERROR_FLAG.
+	    // 2. L = len (input_string)/8.
+	    // 3. N = number_of_bits_to_return/8.
+	    // Comment: L is the bitstring represention of
+	    // the integer resulting from len (input_string)/8.
+	    // L shall be represented as a 32-bit integer.
+	    //
+	    // Comment : N is the bitstring represention of
+	    // the integer resulting from
+	    // number_of_bits_to_return/8. N shall be
+	    // represented as a 32-bit integer.
+	    //
+	    // 4. S = L || N || input_string || 0x80.
+	    // 5. While (len (S) mod outlen)
+	    // Comment : Pad S with zeros, if necessary.
+	    // 0, S = S || 0x00.
+	    //
+	    // Comment : Compute the starting value.
+	    // 6. temp = the Null string.
+	    // 7. i = 0.
+	    // 8. K = Leftmost keylen bits of 0x00010203...1D1E1F.
+	    // 9. While len (temp) < keylen + outlen, do
+	    //
+	    // IV = i || 0outlen - len (i).
+	    //
+	    // 9.1
+	    //
+	    // temp = temp || BCC (K, (IV || S)).
+	    //
+	    // 9.2
+	    //
+	    // i = i + 1.
+	    //
+	    // 9.3
+	    //
+	    // Comment : i shall be represented as a 32-bit
+	    // integer, i.e., len (i) = 32.
+	    //
+	    // Comment: The 32-bit integer represenation of
+	    // i is padded with zeros to outlen bits.
+	    //
+	    // Comment: Compute the requested number of
+	    // bits.
+	    //
+	    // 10. K = Leftmost keylen bits of temp.
+	    //
+	    // 11. X = Next outlen bits of temp.
+	    //
+	    // 12. temp = the Null string.
+	    //
+	    // 13. While len (temp) < number_of_bits_to_return, do
+	    //
+	    // 13.1 X = Block_Encrypt (K, X).
+	    //
+	    // 13.2 temp = temp || X.
+	    //
+	    // 14. requested_bits = Leftmost number_of_bits_to_return of temp.
+	    //
+	    // 15. Return SUCCESS and requested_bits.
+	    private byte[] Block_Cipher_df(byte[] inputString, int bitLength)
+	    {
+	        int outLen = _engine.getBlockSize();
+	        int L = inputString.Length; // already in bytes
+	        int N = bitLength / 8;
+	        // 4 S = L || N || inputstring || 0x80
+	        int sLen = 4 + 4 + L + 1;
+	        int blockLen = ((sLen + outLen - 1) / outLen) * outLen;
+	        byte[] S = new byte[blockLen];
+	        copyIntToByteArray(S, L, 0);
+	        copyIntToByteArray(S, N, 4);
+	        Array.Copy(inputString, 0, S, 8, L);
+	        S[8 + L] = (byte)0x80;
+	        // S already padded with zeros
+
+	        byte[] temp = new byte[_keySizeInBits / 8 + outLen];
+	        byte[] bccOut = new byte[outLen];
+
+	        byte[] IV = new byte[outLen]; 
+	        
+	        int i = 0;
+	        byte[] K = new byte[_keySizeInBits / 8];
+	        Array.Copy(K_BITS, 0, K, 0, K.Length);
+
+	        while (i*outLen*8 < _keySizeInBits + outLen *8)
+	        {
+	            copyIntToByteArray(IV, i, 0);
+	            BCC(bccOut, K, IV, S);
+
+	            int bytesToCopy = ((temp.Length - i * outLen) > outLen)
+	                    ? outLen
+	                    : (temp.Length - i * outLen);
+	            
+	            Array.Copy(bccOut, 0, temp, i * outLen, bytesToCopy);
+	            ++i;
+	        }
+
+	        byte[] X = new byte[outLen];
+	        Array.Copy(temp, 0, K, 0, K.Length);
+	        Array.Copy(temp, K.Length, X, 0, X.Length);
+
+	        temp = new byte[bitLength / 2];
+
+	        i = 0;
+	        _engine.init(true, new KeyParameter(expandKey(K)));
+
+	        while (i * outLen < temp.Length)
+	        {
+	            _engine.processBlock(X, 0, X, 0);
+
+	            int bytesToCopy = ((temp.Length - i * outLen) > outLen)
+	                    ? outLen
+	                    : (temp.Length - i * outLen);
+
+	            Array.Copy(X, 0, temp, i * outLen, bytesToCopy);
+	            i++;
+	        }
+
+	        return temp;
+	    }
+
+	    /*
+	    * 1. chaining_value = 0^outlen    
+	    *    . Comment: Set the first chaining value to outlen zeros.
+	    * 2. n = len (data)/outlen.
+	    * 3. Starting with the leftmost bits of data, split the data into n blocks of outlen bits 
+	    *    each, forming block(1) to block(n). 
+	    * 4. For i = 1 to n do
+	    * 4.1 input_block = chaining_value ^ block(i) .
+	    * 4.2 chaining_value = Block_Encrypt (Key, input_block).
+	    * 5. output_block = chaining_value.
+	    * 6. Return output_block. 
+	     */
+	    private void BCC(byte[] bccOut, byte[] k, byte[] iV, byte[] data)
+	    {
+	        int outlen = _engine.getBlockSize();
+	        byte[] chainingValue = new byte[outlen]; // initial values = 0
+	        int n = data.Length / outlen;
+
+	        byte[] inputBlock = new byte[outlen];
+
+	        _engine.init(true, new KeyParameter(expandKey(k)));
+
+	        _engine.processBlock(iV, 0, chainingValue, 0);
+
+	        for (int i = 0; i < n; i++)
+	        {
+	            XOR(inputBlock, chainingValue, data, i*outlen);
+	            _engine.processBlock(inputBlock, 0, chainingValue, 0);
+	        }
+
+	        Array.Copy(chainingValue, 0, bccOut, 0, bccOut.Length);
+	    }
+
+	    private void copyIntToByteArray(byte[] buf, int value, int offSet)
+	    {
+	        buf[offSet + 0] = ((byte)(value >> 24));
+	        buf[offSet + 1] = ((byte)(value >> 16));
+	        buf[offSet + 2] = ((byte)(value >> 8));
+	        buf[offSet + 3] = ((byte)(value));
+	    }
+
+	    /**
+	     * Return the block size (in bits) of the DRBG.
+	     *
+	     * @return the number of bits produced on each internal round of the DRBG.
+	     */
+	    public int BlockSize
+	    {
+			get {
+				return _V.Length * 8;
+			}
+	    }
+
+	    /**
+	     * Populate a passed in array with random data.
+	     *
+	     * @param output output array for generated bits.
+	     * @param additionalInput additional input to be added to the DRBG in this step.
+	     * @param predictionResistant true if a reseed should be forced, false otherwise.
+	     *
+	     * @return number of bits generated, -1 if a reseed required.
+	     */
+	    public int Generate(byte[] output, byte[] additionalInput, bool predictionResistant)
+	    {
+	        if (_isTDEA)
+	        {
+	            if (_reseedCounter > TDEA_RESEED_MAX)
+	            {
+	                return -1;
+	            }
+
+	            if (Utils.isTooLarge(output, TDEA_MAX_BITS_REQUEST / 8))
+	            {
+	                throw new ArgumentException("Number of bits per request limited to " + TDEA_MAX_BITS_REQUEST);
+	            }
+	        }
+	        else
+	        {
+	            if (_reseedCounter > AES_RESEED_MAX)
+	            {
+	                return -1;
+	            }
+
+	            if (Utils.isTooLarge(output, AES_MAX_BITS_REQUEST / 8))
+	            {
+	                throw new ArgumentException("Number of bits per request limited to " + AES_MAX_BITS_REQUEST);
+	            }
+	        }
+
+	        if (predictionResistant)
+	        {
+	            CTR_DRBG_Reseed_algorithm(additionalInput);
+	            additionalInput = null;
+	        }
+
+	        if (additionalInput != null)
+	        {
+	            additionalInput = Block_Cipher_df(additionalInput, _seedLength);
+	            CTR_DRBG_Update(additionalInput, _Key, _V);
+	        }
+	        else
+	        {
+	            additionalInput = new byte[_seedLength];
+	        }
+
+	        byte[] tmp = new byte[_V.Length];
+
+	        _engine.init(true, new KeyParameter(expandKey(_Key)));
+
+				for (int i = 0; i <= output.Length / tmp.Length; i++)
+	        {
+					int bytesToCopy = ((output.Length - i * tmp.Length) > tmp.Length)
+						? tmp.Length
+	                    : (output.Length - i * _V.Length);
+
+	            if (bytesToCopy != 0)
+	            {
+	                addOneTo(_V);
+
+						_engine.processBlock(_V, 0, tmp, 0);
+
+						Array.Copy(tmp, 0, output, i * tmp.Length, bytesToCopy);
+	            }
+	        }
+
+	        CTR_DRBG_Update(additionalInput, _Key, _V);
+
+	        _reseedCounter++;
+
+	        return output.Length * 8;
+	    }
+
+	    /**
+	      * Reseed the DRBG.
+	      *
+	      * @param additionalInput additional input to be added to the DRBG in this step.
+	      */
+	    public void Reseed(byte[] additionalInput)
+	    {
+	        CTR_DRBG_Reseed_algorithm(additionalInput);
+	    }
+
+	    private boolean isTDEA(BlockCipher cipher)
+	    {
+	        return cipher.AlgorithmName.Equals("DESede") || cipher.AlgorithmName.Equals("TDEA");
+	    }
+
+	    private int getMaxSecurityStrength(BlockCipher cipher, int keySizeInBits)
+	    {
+	        if (isTDEA(cipher) && keySizeInBits == 168)
+	        {
+	            return 112;
+	        }
+	        if (cipher.AlgorithmName.Equals("AES"))
+	        {
+	            return keySizeInBits;
+	        }
+
+	        return -1;
+	    }
+
+	    byte[] expandKey(byte[] key)
+	    {
+	        if (_isTDEA)
+	        {
+	            // expand key to 192 bits.
+	            byte[] tmp = new byte[24];
+
+	            padKey(key, 0, tmp, 0);
+	            padKey(key, 7, tmp, 8);
+	            padKey(key, 14, tmp, 16);
+
+	            return tmp;
+	        }
+	        else
+	        {
+	            return key;
+	        }
+	    }
+
+	    /**
+	     * Pad out a key for TDEA, setting odd parity for each byte.
+	     *
+	     * @param keyMaster
+	     * @param keyOff
+	     * @param tmp
+	     * @param tmpOff
+	     */
+	    private void padKey(byte[] keyMaster, int keyOff, byte[] tmp, int tmpOff)
+	    {
+	        tmp[tmpOff + 0] = (byte)(keyMaster[keyOff + 0] & 0xfe);
+	        tmp[tmpOff + 1] = (byte)((keyMaster[keyOff + 0] << 7) | ((keyMaster[keyOff + 1] & 0xfc) >> 1));
+	        tmp[tmpOff + 2] = (byte)((keyMaster[keyOff + 1] << 6) | ((keyMaster[keyOff + 2] & 0xf8) >> 2));
+	        tmp[tmpOff + 3] = (byte)((keyMaster[keyOff + 2] << 5) | ((keyMaster[keyOff + 3] & 0xf0) >> 3));
+	        tmp[tmpOff + 4] = (byte)((keyMaster[keyOff + 3] << 4) | ((keyMaster[keyOff + 4] & 0xe0) >> 4));
+	        tmp[tmpOff + 5] = (byte)((keyMaster[keyOff + 4] << 3) | ((keyMaster[keyOff + 5] & 0xc0) >> 5));
+	        tmp[tmpOff + 6] = (byte)((keyMaster[keyOff + 5] << 2) | ((keyMaster[keyOff + 6] & 0x80) >> 6));
+	        tmp[tmpOff + 7] = (byte)(keyMaster[keyOff + 6] << 1);
+
+	        for (int i = tmpOff; i <= tmpOff + 7; i++)
+	        {
+	            int b = tmp[i];
+	            tmp[i] = (byte)((b & 0xfe) |
+	                            ((((b >> 1) ^
+	                            (b >> 2) ^
+	                            (b >> 3) ^
+	                            (b >> 4) ^
+	                            (b >> 5) ^
+	                            (b >> 6) ^
+	                            (b >> 7)) ^ 0x01) & 0x01));
+	        }
+	    }
+	}
+}
diff --git a/crypto/src/crypto/prng/drbg/HMacSP800Drbg.cs b/crypto/src/crypto/prng/drbg/HMacSP800Drbg.cs
new file mode 100644
index 000000000..78a710097
--- /dev/null
+++ b/crypto/src/crypto/prng/drbg/HMacSP800Drbg.cs
@@ -0,0 +1,196 @@
+using System;
+
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Prng.Drbg
+{
+	/**
+	 * A SP800-90A HMAC DRBG.
+	 */
+	public class HMacSP800Drbg: SP80090Drbg
+	{
+	    private readonly static long       RESEED_MAX = 1L << (48 - 1);
+		private readonly static int        MAX_BITS_REQUEST = 1 << (19 - 1);
+
+	    private byte[] _K;
+	    private byte[] _V;
+	    private long   _reseedCounter;
+	    private EntropySource _entropySource;
+	    private Mac _hMac;
+	    private int _securityStrength;
+
+	    /**
+	     * Construct a SP800-90A Hash DRBG.
+	     * <p>
+	     * Minimum entropy requirement is the security strength requested.
+	     * </p>
+	     * @param hMac Hash MAC to base the DRBG on.
+	     * @param securityStrength security strength required (in bits)
+	     * @param entropySource source of entropy to use for seeding/reseeding.
+	     * @param personalizationString personalization string to distinguish this DRBG (may be null).
+	     * @param nonce nonce to further distinguish this DRBG (may be null).
+	     */
+	    public HMacSP800Drbg(IMac hMac, int securityStrength, IEntropySource entropySource, byte[] personalizationString, byte[] nonce)
+	    {
+	        if (securityStrength > Utils.getMaxSecurityStrength(hMac))
+	        {
+	            throw new ArgumentException("Requested security strength is not supported by the derivation function");
+	        }
+
+	        if (entropySource.EntropySize < securityStrength)
+	        {
+	            throw new ArgumentException("Not enough entropy for security strength required");
+	        }
+
+	        _securityStrength = securityStrength;
+	        _entropySource = entropySource;
+	        _hMac = hMac;
+
+	        byte[] entropy = getEntropy();
+	        byte[] seedMaterial = Arrays.Concatenate(entropy, nonce, personalizationString);
+
+	        _K = new byte[hMac.GetMacSize()];
+	        _V = new byte[_K.Length];
+	        Arrays.fill(_V, (byte)1);
+
+	        hmac_DRBG_Update(seedMaterial);
+
+	        _reseedCounter = 1;
+	    }
+
+	    private void hmac_DRBG_Update(byte[] seedMaterial)
+	    {
+	        hmac_DRBG_Update_Func(seedMaterial, (byte)0x00);
+	        if (seedMaterial != null)
+	        {
+	            hmac_DRBG_Update_Func(seedMaterial, (byte)0x01);
+	        }
+	    }
+
+	    private void hmac_DRBG_Update_Func(byte[] seedMaterial, byte vValue)
+	    {
+	        _hMac.Init(new KeyParameter(_K));
+
+	        _hMac.BlockUpdate(_V, 0, _V.Length);
+	        _hMac.Update(vValue);
+
+	        if (seedMaterial != null)
+	        {
+	            _hMac.update(seedMaterial, 0, seedMaterial.Length);
+	        }
+
+	        _hMac.DoFinal(_K, 0);
+
+	        _hMac.Init(new KeyParameter(_K));
+	        _hMac.BlockUpdate(_V, 0, _V.Length);
+
+	        _hMac.DoFinal(_V, 0);
+	    }
+
+	    /**
+	     * Return the block size (in bits) of the DRBG.
+	     *
+	     * @return the number of bits produced on each round of the DRBG.
+	     */
+	    public int BlockSize
+	    {
+			get {
+				return _V.Length * 8;
+			}
+	    }
+
+	    /**
+	     * Populate a passed in array with random data.
+	     *
+	     * @param output output array for generated bits.
+	     * @param additionalInput additional input to be added to the DRBG in this step.
+	     * @param predictionResistant true if a reseed should be forced, false otherwise.
+	     *
+	     * @return number of bits generated, -1 if a reseed required.
+	     */
+	    public int Generate(byte[] output, byte[] additionalInput, boolean predictionResistant)
+	    {
+	        int numberOfBits = output.Length * 8;
+
+	        if (numberOfBits > MAX_BITS_REQUEST)
+	        {
+	            throw new IllegalArgumentException("Number of bits per request limited to " + MAX_BITS_REQUEST);
+	        }
+
+	        if (_reseedCounter > RESEED_MAX)
+	        {
+	            return -1;
+	        }
+
+	        if (predictionResistant)
+	        {
+	            reseed(additionalInput);
+	            additionalInput = null;
+	        }
+
+	        // 2.
+	        if (additionalInput != null)
+	        {
+	            hmac_DRBG_Update(additionalInput);
+	        }
+
+	        // 3.
+	        byte[] rv = new byte[output.Length];
+
+	        int m = output.Length / _V.Length;
+
+	        _hMac.Init(new KeyParameter(_K));
+
+	        for (int i = 0; i < m; i++)
+	        {
+	            _hMac.BlockUpdate(_V, 0, _V.Length);
+	            _hMac.DoFinal(_V, 0);
+
+	            Array.Copy(_V, 0, rv, i * _V.Length, _V.Length);
+	        }
+
+	        if (m * _V.Length < rv.Length)
+	        {
+					_hMac.BlockUpdate(_V, 0, _V.Length);
+	            _hMac.DoFinal(_V, 0);
+
+	            Array.Copy(_V, 0, rv, m * _V.Length, rv.Length - (m * _V.Length));
+	        }
+
+	        hmac_DRBG_Update(additionalInput);
+
+	        _reseedCounter++;
+
+	        Array.Copy(rv, 0, output, 0, output.Length);
+
+	        return numberOfBits;
+	    }
+
+	    /**
+	      * Reseed the DRBG.
+	      *
+	      * @param additionalInput additional input to be added to the DRBG in this step.
+	      */
+	    public void Reseed(byte[] additionalInput)
+	    {
+	        byte[] entropy = getEntropy();
+	        byte[] seedMaterial = Arrays.Concatenate(entropy, additionalInput);
+
+	        hmac_DRBG_Update(seedMaterial);
+
+	        _reseedCounter = 1;
+	    }
+
+	    private byte[] getEntropy()
+	    {
+	        byte[] entropy = _entropySource.GetEntropy();
+
+	        if (entropy.Length < (_securityStrength + 7) / 8)
+	        {
+	            throw new IllegalStateException("Insufficient entropy provided by entropy source");
+	        }
+	        return entropy;
+	    }
+	}
+}
diff --git a/crypto/src/crypto/prng/drbg/HashSP800Drbg.cs b/crypto/src/crypto/prng/drbg/HashSP800Drbg.cs
new file mode 100644
index 000000000..868778817
--- /dev/null
+++ b/crypto/src/crypto/prng/drbg/HashSP800Drbg.cs
@@ -0,0 +1,295 @@
+using System;
+using System.Collections;
+
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Prng.Drbg
+{
+	/**
+	 * A SP800-90A Hash DRBG.
+	 */
+	public class HashSP800Drbg: SP80090Drbg
+	{
+	    private readonly static byte[]     ONE = { 0x01 };
+
+		private readonly static long       RESEED_MAX = 1L << (48 - 1);
+		private readonly static int        MAX_BITS_REQUEST = 1 << (19 - 1);
+
+		private static readonly IDictionary seedlens = Platform.CreateHashtable();
+
+		static HashSP800Drbg()
+	    {
+				seedlens.Add("SHA-1", 440);
+				seedlens.Add("SHA-224", 440);
+				seedlens.Add("SHA-256", 440);
+				seedlens.Add("SHA-512/256", 440);
+				seedlens.Add("SHA-512/224", 440);
+				seedlens.Add("SHA-384", 888);
+				seedlens.Add("SHA-512", 888);
+
+	    }
+
+	    private IDigest        _digest;
+	    private byte[]         _V;
+	    private byte[]         _C;
+	    private long           _reseedCounter;
+	    private IEntropySource _entropySource;
+	    private int            _securityStrength;
+	    private int            _seedLength;
+
+	    /**
+	     * Construct a SP800-90A Hash DRBG.
+	     * <p>
+	     * Minimum entropy requirement is the security strength requested.
+	     * </p>
+	     * @param digest  source digest to use for DRB stream.
+	     * @param securityStrength security strength required (in bits)
+	     * @param entropySource source of entropy to use for seeding/reseeding.
+	     * @param personalizationString personalization string to distinguish this DRBG (may be null).
+	     * @param nonce nonce to further distinguish this DRBG (may be null).
+	     */
+	    public HashSP800Drbg(IDigest digest, int securityStrength, IEntropySource entropySource, byte[] personalizationString, byte[] nonce)
+	    {
+	        if (securityStrength > Utils.getMaxSecurityStrength(digest))
+	        {
+	            throw new ArgumentException("Requested security strength is not supported by the derivation function");
+	        }
+
+	        if (entropySource.EntropySize < securityStrength)
+	        {
+	            throw new ArgumentException("Not enough entropy for security strength required");
+	        }
+
+	        _digest = digest;
+	        _entropySource = entropySource;
+	        _securityStrength = securityStrength;
+	        _seedLength = ((Integer)seedlens.get(digest.getAlgorithmName())).intValue();
+
+	        // 1. seed_material = entropy_input || nonce || personalization_string.
+	        // 2. seed = Hash_df (seed_material, seedlen).
+	        // 3. V = seed.
+	        // 4. C = Hash_df ((0x00 || V), seedlen). Comment: Preceed V with a byte
+	        // of zeros.
+	        // 5. reseed_counter = 1.
+	        // 6. Return V, C, and reseed_counter as the initial_working_state
+
+	        byte[] entropy = getEntropy();
+	        byte[] seedMaterial = Arrays.Concatenate(entropy, nonce, personalizationString);
+	        byte[] seed = Utils.hash_df(_digest, seedMaterial, _seedLength);
+
+	        _V = seed;
+	        byte[] subV = new byte[_V.Length + 1];
+	        Array.Copy(_V, 0, subV, 1, _V.Length);
+	        _C = Utils.hash_df(_digest, subV, _seedLength);
+
+	        _reseedCounter = 1;
+	    }
+
+	    /**
+	     * Return the block size (in bits) of the DRBG.
+	     *
+	     * @return the number of bits produced on each internal round of the DRBG.
+	     */
+	    public int BlockSize
+	    {
+			get {
+				return _digest.GetDigestSize () * 8;
+			}
+	    }
+
+	    /**
+	     * Populate a passed in array with random data.
+	     *
+	     * @param output output array for generated bits.
+	     * @param additionalInput additional input to be added to the DRBG in this step.
+	     * @param predictionResistant true if a reseed should be forced, false otherwise.
+	     *
+	     * @return number of bits generated, -1 if a reseed required.
+	     */
+	    public int Generate(byte[] output, byte[] additionalInput, bool predictionResistant)
+	    {
+	        // 1. If reseed_counter > reseed_interval, then return an indication that a
+	        // reseed is required.
+	        // 2. If (additional_input != Null), then do
+	        // 2.1 w = Hash (0x02 || V || additional_input).
+	        // 2.2 V = (V + w) mod 2^seedlen
+	        // .
+	        // 3. (returned_bits) = Hashgen (requested_number_of_bits, V).
+	        // 4. H = Hash (0x03 || V).
+	        // 5. V = (V + H + C + reseed_counter) mod 2^seedlen
+	        // .
+	        // 6. reseed_counter = reseed_counter + 1.
+	        // 7. Return SUCCESS, returned_bits, and the new values of V, C, and
+	        // reseed_counter for the new_working_state.
+	        int numberOfBits = output.Length*8;
+
+	        if (numberOfBits > MAX_BITS_REQUEST)
+	        {
+	            throw new ArgumentException("Number of bits per request limited to " + MAX_BITS_REQUEST);
+	        }
+
+	        if (_reseedCounter > RESEED_MAX)
+	        {
+	            return -1;
+	        }
+
+	        if (predictionResistant)
+	        {   
+	            reseed(additionalInput);
+	            additionalInput = null;
+	        }
+
+	        // 2.
+	        if (additionalInput != null)
+	        {
+	            byte[] newInput = new byte[1 + _V.Length + additionalInput.Length];
+	            newInput[0] = 0x02;
+	            Array.Copy(_V, 0, newInput, 1, _V.Length);
+	            // TODO: inOff / inLength
+	            Array.Copy(additionalInput, 0, newInput, 1 + _V.Length, additionalInput.Length);
+	            byte[] w = hash(newInput);
+
+	            addTo(_V, w);
+	        }
+	        
+	        // 3.
+	        byte[] rv = hashgen(_V, numberOfBits);
+	        
+	        // 4.
+	        byte[] subH = new byte[_V.Length + 1];
+	        Array.Copy(_V, 0, subH, 1, _V.Length);
+	        subH[0] = 0x03;
+	        
+	        byte[] H = hash(subH);
+	        
+	        // 5.
+	        addTo(_V, H);
+	        addTo(_V, _C);
+	        byte[] c = new byte[4];
+	        c[0] = (byte)(_reseedCounter >> 24);
+	        c[1] = (byte)(_reseedCounter >> 16);
+	        c[2] = (byte)(_reseedCounter >> 8);
+	        c[3] = (byte)_reseedCounter;
+	        
+	        addTo(_V, c);
+
+	        _reseedCounter++;
+
+	        Array.Copy(rv, 0, output, 0, output.Length);
+
+	        return numberOfBits;
+	    }
+
+	    private byte[] getEntropy()
+	    {
+	        byte[] entropy = _entropySource.getEntropy();
+	        if (entropy.Length < (_securityStrength + 7) / 8)
+	        {
+	            throw new IllegalStateException("Insufficient entropy provided by entropy source");
+	        }
+	        return entropy;
+	    }
+
+	    // this will always add the shorter length byte array mathematically to the
+	    // longer length byte array.
+	    // be careful....
+	    private void addTo(byte[] longer, byte[] shorter)
+	    {
+	        int carry = 0;
+	        for (int i=1;i <= shorter.Length; i++) // warning
+	        {
+	            int res = (longer[longer.Length-i] & 0xff) + (shorter[shorter.Length-i] & 0xff) + carry;
+	            carry = (res > 0xff) ? 1 : 0;
+	            longer[longer.Length-i] = (byte)res;
+	        }
+	        
+	        for (int i=shorter.Length+1;i <= longer.Length; i++) // warning
+	        {
+	            int res = (longer[longer.Length-i] & 0xff) + carry;
+	            carry = (res > 0xff) ? 1 : 0;
+	            longer[longer.Length-i] = (byte)res;
+	        }
+	    }
+
+	    /**
+	      * Reseed the DRBG.
+	      *
+	      * @param additionalInput additional input to be added to the DRBG in this step.
+	      */
+	    public void Reseed(byte[] additionalInput)
+	    {
+	        // 1. seed_material = 0x01 || V || entropy_input || additional_input.
+	        //
+	        // 2. seed = Hash_df (seed_material, seedlen).
+	        //
+	        // 3. V = seed.
+	        //
+	        // 4. C = Hash_df ((0x00 || V), seedlen).
+	        //
+	        // 5. reseed_counter = 1.
+	        //
+	        // 6. Return V, C, and reseed_counter for the new_working_state.
+	        //
+	        // Comment: Precede with a byte of all zeros.
+	        byte[] entropy = getEntropy();
+	        byte[] seedMaterial = Arrays.Concatenate(ONE, _V, entropy, additionalInput);
+	        byte[] seed = Utils.hash_df(_digest, seedMaterial, _seedLength);
+
+	        _V = seed;
+	        byte[] subV = new byte[_V.Length + 1];
+	        subV[0] = 0x00;
+	        Array.Copy(_V, 0, subV, 1, _V.Length);
+	        _C = Utils.hash_df(_digest, subV, _seedLength);
+
+	        _reseedCounter = 1;
+	    }
+	    
+	    private byte[] hash(byte[] input)
+	    {
+	        byte[] hash = new byte[_digest.GetDigestSize()];
+	        doHash(input, hash);
+	        return hash;
+	    }
+
+	    private void doHash(byte[] input, byte[] output)
+	    {
+	        _digest.BlockUpdate(input, 0, input.Length);
+	        _digest.DoFinal(output, 0);
+	    }
+
+	    // 1. m = [requested_number_of_bits / outlen]
+	    // 2. data = V.
+	    // 3. W = the Null string.
+	    // 4. For i = 1 to m
+	    // 4.1 wi = Hash (data).
+	    // 4.2 W = W || wi.
+	    // 4.3 data = (data + 1) mod 2^seedlen
+	    // .
+	    // 5. returned_bits = Leftmost (requested_no_of_bits) bits of W.
+	    private byte[] hashgen(byte[] input, int lengthInBits)
+	    {
+	        int digestSize = _digest.GetDigestSize();
+	        int m = (lengthInBits / 8) / digestSize;
+
+	        byte[] data = new byte[input.Length];
+	        Array.Copy(input, 0, data, 0, input.Length);
+
+	        byte[] W = new byte[lengthInBits / 8];
+
+	        byte[] dig = new byte[_digest.GetDigestSize()];
+	        for (int i = 0; i <= m; i++)
+	        {
+	            doHash(data, dig);
+
+	            int bytesToCopy = ((W.Length - i * dig.Length) > dig.Length)
+	                    ? dig.Length
+	                    : (W.Length - i * dig.Length);
+	            Array.Copy(dig, 0, W, i * dig.Length, bytesToCopy);
+
+	            addTo(data, ONE);
+	        }
+
+	        return W;
+	    }    
+	}
+}
diff --git a/crypto/src/crypto/prng/drbg/SP80090Drbg.cs b/crypto/src/crypto/prng/drbg/SP80090Drbg.cs
new file mode 100644
index 000000000..c39cf365f
--- /dev/null
+++ b/crypto/src/crypto/prng/drbg/SP80090Drbg.cs
@@ -0,0 +1,33 @@
+namespace Org.BouncyCastle.Crypto.Prng.Drbg
+{
+	/**
+	 * Interface to SP800-90A deterministic random bit generators.
+	 */
+	public interface SP80090Drbg
+	{
+	    /**
+	     * Return the block size of the DRBG.
+	     *
+	     * @return the block size (in bits) produced by each round of the DRBG.
+	     */
+		int BlockSize { get; }
+
+	    /**
+	     * Populate a passed in array with random data.
+	     *
+	     * @param output output array for generated bits.
+	     * @param additionalInput additional input to be added to the DRBG in this step.
+	     * @param predictionResistant true if a reseed should be forced, false otherwise.
+	     *
+	     * @return number of bits generated, -1 if a reseed required.
+	     */
+	    int Generate(byte[] output, byte[] additionalInput, bool predictionResistant);
+
+	    /**
+	     * Reseed the DRBG.
+	     *
+	     * @param additionalInput additional input to be added to the DRBG in this step.
+	     */
+	    void Reseed(byte[] additionalInput);
+	}
+}
diff --git a/crypto/src/crypto/prng/drbg/Utils.cs b/crypto/src/crypto/prng/drbg/Utils.cs
new file mode 100644
index 000000000..b5f3b5830
--- /dev/null
+++ b/crypto/src/crypto/prng/drbg/Utils.cs
@@ -0,0 +1,103 @@
+using System;
+using System.Collections;
+
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Prng.Drbg
+{
+	internal class Utils
+	{
+		private static readonly IDictionary maxSecurityStrengths = Platform.CreateHashtable();
+
+		static Utils()
+	    {
+	        maxSecurityStrengths.put("SHA-1", 128);
+
+	        maxSecurityStrengths.put("SHA-224", 192);
+	        maxSecurityStrengths.put("SHA-256", 256);
+	        maxSecurityStrengths.put("SHA-384", 256);
+	        maxSecurityStrengths.put("SHA-512", 256);
+
+	        maxSecurityStrengths.put("SHA-512/224", 192);
+	        maxSecurityStrengths.put("SHA-512/256", 256);
+	    }
+
+	    internal static int getMaxSecurityStrength(IDigest d)
+	    {
+	        return (int)maxSecurityStrengths[d.AlgorithmName];
+	    }
+
+		internal static int getMaxSecurityStrength(IMac m)
+	    {
+	        String name = m.getAlgorithmName();
+
+	        return (int)maxSecurityStrengths[name.substring(0, name.indexOf("/"))];
+	    }
+
+	    /**
+	     * Used by both Dual EC and Hash.
+	     */
+	    internal static byte[] hash_df(Digest digest, byte[] seedMaterial, int seedLength)
+	    {
+	         // 1. temp = the Null string.
+	        // 2. .
+	        // 3. counter = an 8-bit binary value representing the integer "1".
+	        // 4. For i = 1 to len do
+	        // Comment : In step 4.1, no_of_bits_to_return
+	        // is used as a 32-bit string.
+	        // 4.1 temp = temp || Hash (counter || no_of_bits_to_return ||
+	        // input_string).
+	        // 4.2 counter = counter + 1.
+	        // 5. requested_bits = Leftmost (no_of_bits_to_return) of temp.
+	        // 6. Return SUCCESS and requested_bits.
+	        byte[] temp = new byte[(seedLength + 7) / 8];
+
+	        int len = temp.Length / digest.getDigestSize();
+	        int counter = 1;
+
+	        byte[] dig = new byte[digest.getDigestSize()];
+
+	        for (int i = 0; i <= len; i++)
+	        {
+	            digest.Update((byte)counter);
+
+	            digest.Update((byte)(seedLength >> 24));
+	            digest.Update((byte)(seedLength >> 16));
+	            digest.Update((byte)(seedLength >> 8));
+	            digest.Update((byte)seedLength);
+
+	            digest.BlockUpdate(seedMaterial, 0, seedMaterial.Length);
+
+	            digest.DoFinal(dig, 0);
+
+	            int bytesToCopy = ((temp.Length - i * dig.Length) > dig.Length)
+	                    ? dig.Length
+	                    : (temp.Length - i * dig.Length);
+	            Array.Copy(dig, 0, temp, i * dig.Length, bytesToCopy);
+
+	            counter++;
+	        }
+
+	        // do a left shift to get rid of excess bits.
+	        if (seedLength % 8 != 0)
+	        {
+	            int shift = 8 - (seedLength % 8);
+	            int carry = 0;
+
+	            for (int i = 0; i != temp.Length; i++)
+	            {
+	                uint b = temp[i] & 0xff;
+	                temp[i] = (byte)((b >> shift) | (carry << (8 - shift)));
+	                carry = b;
+	            }
+	        }
+
+	        return temp;
+	    }
+
+	    internal static boolean isTooLarge(byte[] bytes, int maxBytes)
+	    {
+	        return bytes != null && bytes.Length > maxBytes;
+	    }
+	}
+}
diff --git a/crypto/test/src/crypto/prng/test/CtrDrbgTest.cs b/crypto/test/src/crypto/prng/test/CtrDrbgTest.cs
new file mode 100644
index 000000000..e081ec132
--- /dev/null
+++ b/crypto/test/src/crypto/prng/test/CtrDrbgTest.cs
@@ -0,0 +1,524 @@
+using System;
+
+using Org.BouncyCastle.Crypto.Engines;
+using Org.BouncyCastle.Crypto.Prng.Drbg;
+using Org.BouncyCastle.Utilities.Test;
+using Org.BouncyCastle.Utilities.Encoders;
+using NUnit.Framework;
+using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Crypto.Parameters;
+
+namespace Org.BouncyCastle.Crypto.Prng.Test
+{
+    /**
+     * CTR DRBG Test
+     */
+    [TestFixture]
+    public class CtrDrbgTest : SimpleTest
+    {
+        public override String Name {
+            get {
+                return "CTRDRBGTest";
+            }
+        }
+
+        public static void main(String[] args)
+        {
+            RunTest(new CtrDrbgTest());
+        }
+
+        private DRBGTestVector[] createTestVectorData()
+        {
+            return new DRBGTestVector[]
+                {
+                new DRBGTestVector(
+                            new DesEdeEngine(), 168,
+                            new Bit232EntropyProvider().Get(232),
+                            false,
+                            "20212223242526",
+                            112,
+                            new String[]
+                                {
+                                    "ABC88224514D0316EA3D48AEE3C9A2B4",
+                                    "D3D3F372E43E7ABDC4FA293743EED076"
+                                }
+                        ),
+                new DRBGTestVector(
+                            new DesEdeEngine(), 168,
+                            new Bit232EntropyProvider().Get(232),
+                            false,
+                            "20212223242526",
+                            112,
+                            new String[]
+                                {
+                                    "D4564EE072ACA5BD279536E14F94CB12",
+                                    "1CCD9AFEF15A9679BA75E35225585DEA"
+                                }
+                        )
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBC"),
+                new DRBGTestVector(
+                            new DesEdeEngine(), 168,
+                            new Bit232EntropyProvider().Get(232),
+                            false,
+                            "20212223242526",
+                            112,
+                            new String[]
+                                {
+                                    "760BED7D92B083B10AF31CF0656081EB",
+                                    "FD1AC41482384D823CF3FD6F0E6C88B3"
+                                }
+                        )
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C"),
+                new DRBGTestVector(
+                            new DesEdeEngine(), 168,
+                            new Bit232EntropyProvider().Get(232),
+                            false,
+                            "20212223242526",
+                            112,
+                            new String[]
+                                {
+                                    "7A4C1D7ADC8A67FDB50100ED23583A2C",
+                                    "43044D311C0E07541CA5C8B0916976B2"
+                                }
+                        )
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C")
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBC"),
+                new DRBGTestVector(
+                            new DesEdeEngine(), 168,
+                            new Bit232EntropyProvider().Get(232),
+                            true,
+                            "20212223242526",
+                            112,
+                            new String[]
+                                {
+                                    "8FB78ABCA75C9F284E974E36141866BC",
+                                    "9D9745FF31C42A4488CBB771B13B5D86"
+                                }
+                        ),
+                new DRBGTestVector(
+                            new DesEdeEngine(), 168,
+                            new Bit232EntropyProvider().Get(232),
+                            true,
+                            "20212223242526",
+                            112,
+                            new String[]
+                                {
+                                    "0E389920A09B485AA4ABD0CA7E60D89C",
+                                    "F4478EC6659A0D3577625B0C73A211DD"
+                                }
+                        )
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBC"),
+                new DRBGTestVector(
+                            new DesEdeEngine(), 168,
+                            new Bit232EntropyProvider().Get(232),
+                            true,
+                            "20212223242526",
+                            112,
+                            new String[]
+                                {
+                                    "64983055D014550B39DE699E43130B64",
+                                    "035FDDA8582A2214EC722C410A8D95D3"
+                                }
+                        )
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C"),
+                new DRBGTestVector(
+                            new DesEdeEngine(), 168,
+                            new Bit232EntropyProvider().Get(232),
+                            true,
+                            "20212223242526",
+                            112,
+                            new String[]
+                                {
+                                    "A29C1A8C42FBC562D7D1DBA7DC541FFE",
+                                    "0BDA66B049429061C013E4228C2F44C6"
+                                }
+                        )
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C")
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBC"),
+                new DRBGTestVector(
+                            new AesFastEngine(), 128,
+                            new Bit256EntropyProvider().Get(256),
+                            false,
+                            "2021222324252627",
+                            128,
+                            new String[]
+                                {
+                                    "8CF59C8CF6888B96EB1C1E3E79D82387AF08A9E5FF75E23F1FBCD4559B6B997E",
+                                    "69CDEF912C692D61B1DA4C05146B52EB7B8849BD87937835328254EC25A9180E"
+                                }
+                        ),
+                new DRBGTestVector(
+                            new AesFastEngine(), 128,
+                            new Bit256EntropyProvider().Get(256),
+                            false,
+                            "2021222324252627",
+                            128,
+                            new String[]
+                                {
+                                    "E8C74A4B7BFFB53BEB80E78CA86BB6DF70E2032AEB473E0DD54D2339CEFCE9D0",
+                                    "26B3F823B4DBAFC23B141375E10B3AEB7A0B5DEF1C7D760B6F827D01ECD17AC7"
+                                }
+                        )
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBF"),
+                new DRBGTestVector(
+                           new AesFastEngine(), 128,
+                           new Bit256EntropyProvider().Get(256),
+                           false,
+                           "2021222324252627",
+                           128,
+                           new String[]
+                               {
+                                   "18FDEFBDC43D7A36D5D6D862205765D1D701C9F237007030DF1B8E70EE4EEE29",
+                                   "9888F1D38BB1CCE31B363AA1BD9B39616876C30DEE1FF0B7BD8C4C441715C833"
+                               }
+                       )
+               .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F"),
+                new DRBGTestVector(
+                            new AesFastEngine(), 128,
+                            new Bit256EntropyProvider().Get(256),
+                            true,
+                            "2021222324252627",
+                            128,
+                            new String[]
+                                {
+                                    "BFF4B85D68C84529F24F69F9ACF1756E29BA648DDEB825C225FA32BA490EF4A9",
+                                    "9BD2635137A52AF7D0FCBEFEFB97EA93A0F4C438BD98956C0DACB04F15EE25B3"
+                                }
+                        ),
+                new DRBGTestVector(
+                            new AesFastEngine(), 128,
+                            new Bit256EntropyProvider().Get(256),
+                            true,
+                            "2021222324252627",
+                            128,
+                            new String[]
+                                {
+                                    "4573AC8BBB33D7CC4DBEF3EEDF6EAE748B536C3A1082CEE4948CDB51C83A7F9C",
+                                    "99C628CDD87BD8C2F1FE443AA7F761DA16886436326323354DA6311FFF5BC678"
+                                }
+                        )
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBF"),
+                new DRBGTestVector(
+                           new AesFastEngine(), 128,
+                           new Bit256EntropyProvider().Get(256),
+                           true,
+                           "2021222324252627",
+                           128,
+                           new String[]
+                               {
+                                   "F324104E2FA14F79D8AA60DF06B93B3BC157324958F0A7EE1E193677A70E0250",
+                                   "78F4C840134F40DC001BFAD3A90B5EF4DEBDBFAC3CFDF0CD69A89DC4FD34713F"
+                               }
+                       )
+               .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F"),
+                new DRBGTestVector(
+                            new AesFastEngine(), 192,
+                            new Bit320EntropyProvider().Get(320),
+                            false,
+                            "202122232425262728292A2B",
+                            192,
+                            new String[]
+                                {
+                                    "E231244B3235B085C81604424357E85201E3828B5C45568679A5555F867AAC8C",
+                                    "DDD0F7BCCADADAA31A67652259CE569A271DD85CF66C3D6A7E9FAED61F38D219"
+                                }
+                        )
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F6061626364656667"),
+                new DRBGTestVector(
+                        new AesFastEngine(), 192,
+                        new Bit320EntropyProvider().Get(320),
+                        true,
+                        "202122232425262728292A2B",
+                        192,
+                        new String[]
+                            {
+                                "F780D4A2C25CF8EE7407D948EC0B724A4235D8B20E65081392755CA7912AD7C0",
+                                "BA14617F915BA964CB79276BDADC840C14B631BBD1A59097054FA6DFF863B238"
+                            }
+                    )
+            .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F6061626364656667"),
+                new DRBGTestVector(
+                            new AesFastEngine(), 256,
+                            new Bit384EntropyProvider().Get(384),
+                            false,
+                            "202122232425262728292A2B2C2D2E2F",
+                            256,
+                            new String[]
+                                {
+                                    "47111E146562E9AA2FB2A1B095D37A8165AF8FC7CA611D632BE7D4C145C83900",
+                                    "98A28E3B1BA363C9DAF0F6887A1CF52B833D3354D77A7C10837DD63DD2E645F8"
+                                }
+                        )
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F606162636465666768696A6B6C6D6E6F")
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F808182838485868788898A8B8C8D8E8F")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECF"),
+                new DRBGTestVector(
+                            new AesFastEngine(), 256,
+                            new Bit384EntropyProvider().Get(384),
+                            true,
+                            "202122232425262728292A2B2C2D2E2F",
+                            256,
+                            new String[]
+                                {
+                                    "71BB3F9C9CEAF4E6C92A83EB4C7225010EE150AC75E23F5F77AD5073EF24D88A",
+                                    "386DEBBBF091BBF0502957B0329938FB836B82E594A2F5FDD5EB28D4E35528F4"
+                                }
+                        )
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F808182838485868788898A8B8C8D8E8F")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECF"),
+                new DRBGTestVector(
+                            new AesFastEngine(), 256,
+                            new Bit384EntropyProvider().Get(384),
+                            true,
+                            "202122232425262728292A2B2C2D2E2F",
+                            256,
+                            new String[]
+                                {
+                                    "1A2E3FEE9056E98D375525FDC2B63B95B47CE51FCF594D804BD5A17F2E01139B",
+                                    "601F95384F0D85946301D1EACE8F645A825CE38F1E2565B0C0C439448E9CA8AC"
+                                }
+                        )
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F606162636465666768696A6B6C6D6E6F"),
+                new DRBGTestVector(
+                            new AesFastEngine(), 256,
+                            new Bit384EntropyProvider().Get(384),
+                            true,
+                            "202122232425262728292A2B2C2D2E2F",
+                            256,
+                            new String[]
+                                {
+                                    "EAE6BCE781807E524D26605EA198077932D01EEB445B9AC6C5D99C101D29F46E",
+                                    "738E99C95AF59519AAD37FF3D5180986ADEBAB6E95836725097E50A8D1D0BD28"
+                                }
+                        )
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F606162636465666768696A6B6C6D6E6F")
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F808182838485868788898A8B8C8D8E8F")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECF"),
+                new DRBGTestVector(
+                            new AesFastEngine(), 256,
+                            new Bit384EntropyProvider().Get(384),
+                            true,
+                            "202122232425262728292A2B2C2D2E2F",
+                            256,
+                            new String[]
+                                {
+                                    "eae6bce781807e524d26605ea198077932d01eeb445b9ac6c5d99c101d29f46e30b27377",
+                                    "ec51b55b49904c3ff9e13939f1cf27398993e1b3acb2b0be0be8761261428f0aa8ba2657"
+                                }
+                        )
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F606162636465666768696A6B6C6D6E6F")
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F808182838485868788898A8B8C8D8E8F")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECF")
+                };
+        }
+
+        public override void PerformTest()
+        {
+            DRBGTestVector[] tests = createTestVectorData();
+            SP80090Drbg d;
+            DRBGTestVector tv;
+            byte[] output;
+
+            for (int i = 0; i != tests.Length; i++)
+            {
+                tv = tests[i];
+
+                byte[] nonce = tv.nonce();
+                byte[] personalisationString = tv.personalizationString();
+
+                d = new CtrSP800Drbg(tv.getCipher(), tv.keySizeInBits(), tv.securityStrength(), tv.entropySource(), personalisationString, nonce);
+
+                output = new byte[tv.expectedValue(0).Length];
+
+                d.Generate(output, tv.additionalInput(0), tv.predictionResistance());
+
+                byte[] expected = tv.expectedValue(0);
+
+                if (!AreEqual(expected, output))
+                {
+                    Fail("Test #" + (i + 1) + ".1 failed, expected " + Hex.ToHexString(tv.expectedValue(0)) + " got " + Hex.ToHexString(output));
+                }
+
+                output = new byte[tv.expectedValue(0).Length];
+
+                d.Generate(output, tv.additionalInput(1), tv.predictionResistance());
+
+                expected = tv.expectedValue(1);
+                if (!AreEqual(expected, output))
+                {
+                    Fail("Test #" + (i + 1) + ".2 failed, expected " + Hex.ToHexString(tv.expectedValue(1)) + " got " + Hex.ToHexString(output));
+                }
+            }
+
+            // DESede/TDEA key parity test
+            tv = tests[0];
+
+            SP80090Drbg drbg = new CtrSP800Drbg(new KeyParityCipher(tv.getCipher()), tv.keySizeInBits(), tv.securityStrength(), tv.entropySource(), tv.personalizationString(), tv.nonce());
+
+            output = new byte[tv.expectedValue(0).Length];
+
+            drbg.Generate(output, tv.additionalInput(0), tv.predictionResistance());
+
+            // Exception tests
+            try
+            {
+                d = new CtrSP800Drbg(new AesEngine(), 256, 256, new Bit232EntropyProvider().Get(128), null, null);
+                Fail("no exception thrown");
+            }
+            catch (ArgumentException e)
+            {
+                if (!e.Message.Equals("Not enough entropy for security strength required"))
+                {
+                    Fail("Wrong exception", e);
+                }
+            }
+
+            try
+            {
+                d = new CtrSP800Drbg(new DesEdeEngine(), 256, 256, new Bit232EntropyProvider().Get(232), null, null);
+                Fail("no exception thrown");
+            }
+            catch (ArgumentException e)
+            {
+                if (!e.Message.Equals("Requested security strength is not supported by block cipher and key size"))
+                {
+                    Fail("Wrong exception", e);
+                }
+            }
+
+            try
+            {
+                d = new CtrSP800Drbg(new DesEdeEngine(), 168, 256, new Bit232EntropyProvider().Get(232), null, null);
+                Fail("no exception thrown");
+            }
+            catch (ArgumentException e)
+            {
+                if (!e.Message.Equals("Requested security strength is not supported by block cipher and key size"))
+                {
+                    Fail("Wrong exception", e);
+                }
+            }
+
+            try
+            {
+                d = new CtrSP800Drbg(new AesEngine(), 192, 256, new Bit232EntropyProvider().Get(232), null, null);
+                Fail("no exception thrown");
+            }
+            catch (ArgumentException e)
+            {
+                if (!e.Message.Equals("Requested security strength is not supported by block cipher and key size"))
+                {
+                    Fail("Wrong exception", e);
+                }
+            }
+        }
+
+        internal class Bit232EntropyProvider : TestEntropySourceProvider
+        {
+            internal Bit232EntropyProvider() : base(Hex.Decode(
+                   "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C" +
+                   "808182838485868788898A8B8C8D8E8F909192939495969798999A9B9C" +
+                   "C0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDC"), true)
+            { }
+        }
+
+        internal class Bit256EntropyProvider : TestEntropySourceProvider
+        {
+            internal Bit256EntropyProvider(): base(Hex.Decode(
+                    "0001020304050607" +
+                    "08090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F" +
+                    "8081828384858687" +
+                    "88898A8B8C8D8E8F909192939495969798999A9B9C9D9E9F" +
+                    "C0C1C2C3C4C5C6C7" +
+                    "C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDEDF"), true)
+            { }
+       }
+
+        internal class Bit320EntropyProvider : TestEntropySourceProvider
+        {
+            internal Bit320EntropyProvider() : base(Hex.Decode(
+                "000102030405060708090A0B0C0D0E0F" +
+                "101112131415161718191A1B1C1D1E1F2021222324252627" +
+                "808182838485868788898A8B8C8D8E8F" +
+                "909192939495969798999A9B9C9D9E9FA0A1A2A3A4A5A6A7" +
+                "C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF" +
+                "D0D1D2D3D4D5D6D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6E7"), true)
+            { }
+        }
+
+        internal class Bit384EntropyProvider : TestEntropySourceProvider
+        {
+            internal Bit384EntropyProvider() : base(Hex.Decode(
+                "000102030405060708090A0B0C0D0E0F1011121314151617" +
+                "18191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F" +
+                "808182838485868788898A8B8C8D8E8F9091929394959697" +
+                "98999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAF" +
+                "C0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7" +
+                "D8D9DADBDCDDDEDFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEF"), true)
+            { }
+        }
+
+        internal class KeyParityCipher : IBlockCipher
+        {
+            private IBlockCipher cipher;
+
+            internal KeyParityCipher(IBlockCipher cipher)
+            {
+                this.cipher = cipher;
+            }
+
+            public void Init(bool forEncryption, ICipherParameters parameters)
+            {
+                byte[] k = Arrays.Clone(((KeyParameter)parameters).GetKey());
+
+                DesEdeParameters.SetOddParity(k);
+
+                if (!Arrays.AreEqual(((KeyParameter)parameters).GetKey(), k))
+                {
+                    throw new ArgumentException("key not odd parity");
+                }
+
+                cipher.Init(forEncryption, parameters);
+            }
+
+            public String AlgorithmName
+            {
+                get
+                {
+                    return cipher.AlgorithmName;
+                }
+            }
+
+            public bool IsPartialBlockOkay
+            {
+                get
+                {
+                    return false;
+                }
+            }
+
+            public int GetBlockSize()
+            {
+                return cipher.GetBlockSize();
+            }
+
+            public int ProcessBlock(byte[] input, int inOff, byte[] output, int outOff)
+            {
+                return cipher.ProcessBlock(input, inOff, output, outOff);
+            }
+
+            public void Reset()
+            {
+                cipher.Reset();
+            }
+        }
+
+    }
+
+}
diff --git a/crypto/test/src/crypto/prng/test/DRGBTestVector.cs b/crypto/test/src/crypto/prng/test/DRGBTestVector.cs
new file mode 100644
index 000000000..a4129b9f8
--- /dev/null
+++ b/crypto/test/src/crypto/prng/test/DRGBTestVector.cs
@@ -0,0 +1,129 @@
+using Org.BouncyCastle.Utilities.Encoders;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Org.BouncyCastle.Crypto.Prng.Test
+{
+    public class DRBGTestVector
+    {
+        private IDigest _digest;
+        private IBlockCipher _cipher;
+        private int _keySizeInBits;
+        private IEntropySource _eSource;
+        private bool _pr;
+        private String _nonce;
+        private String _personalisation;
+        private int _ss;
+        private String[] _ev;
+        private List<string> _ai = new List<string>();
+
+        public DRBGTestVector(IDigest digest, IEntropySource eSource, bool predictionResistance, String nonce, int securityStrength, String[] expected)
+        {
+            _digest = digest;
+            _eSource = eSource;
+            _pr = predictionResistance;
+            _nonce = nonce;
+            _ss = securityStrength;
+            _ev = expected;
+            _personalisation = null;
+        }
+
+        public DRBGTestVector(IBlockCipher cipher, int keySizeInBits, IEntropySource eSource, bool predictionResistance, String nonce, int securityStrength, String[] expected)
+        {
+            _cipher = cipher;
+            _keySizeInBits = keySizeInBits;
+            _eSource = eSource;
+            _pr = predictionResistance;
+            _nonce = nonce;
+            _ss = securityStrength;
+            _ev = expected;
+            _personalisation = null;
+        }
+
+        public IDigest getDigest()
+        {
+            return _digest;
+        }
+
+        public IBlockCipher getCipher()
+        {
+            return _cipher;
+        }
+
+        public int keySizeInBits()
+        {
+            return _keySizeInBits;
+        }
+
+        public DRBGTestVector addAdditionalInput(String input)
+        {
+            _ai.Add(input);
+
+            return this;
+        }
+
+        public DRBGTestVector setPersonalizationString(String p)
+        {
+            _personalisation = p;
+
+            return this;
+        }
+
+        public IEntropySource entropySource()
+        {
+            return _eSource;
+        }
+
+        public bool predictionResistance()
+        {
+            return _pr;
+        }
+
+        public byte[] nonce()
+        {
+            if (_nonce == null)
+            {
+                return null;
+            }
+
+            return Hex.Decode(_nonce);
+        }
+
+        public byte[] personalizationString()
+        {
+            if (_personalisation == null)
+            {
+                return null;
+            }
+
+            return Hex.Decode(_personalisation);
+        }
+
+        public int securityStrength()
+        {
+            return _ss;
+        }
+
+        public byte[] expectedValue(int index)
+        {
+            return Hex.Decode(_ev[index]);
+        }
+
+        public byte[] additionalInput(int position)
+        {
+            int len = _ai.Count;
+            byte[] rv;
+            if (position >= len)
+            {
+                rv = null;
+            }
+            else
+            {
+                rv = Hex.Decode((string)(_ai[position]));
+            }
+            return rv;
+        }
+
+    }
+}
diff --git a/crypto/test/src/crypto/prng/test/HMacDrbgTest.cs b/crypto/test/src/crypto/prng/test/HMacDrbgTest.cs
new file mode 100644
index 000000000..b8d383663
--- /dev/null
+++ b/crypto/test/src/crypto/prng/test/HMacDrbgTest.cs
@@ -0,0 +1,511 @@
+
+using System;
+
+using Org.BouncyCastle.Crypto.Digests;
+using Org.BouncyCastle.Crypto.Macs;
+using Org.BouncyCastle.Crypto.Prng.Drbg;
+using Org.BouncyCastle.Utilities.Test;
+using Org.BouncyCastle.Utilities.Encoders;
+using NUnit.Framework;
+
+namespace Org.BouncyCastle.Crypto.Prng.Test
+{
+    /**
+     * HMAC SP800-90 DRBG
+     */
+    [TestFixture]
+    public class HMacDrbgTest : SimpleTest
+    {
+        public override String Name
+        {
+            get
+            {
+                return "HMacDRBG";
+            }
+        }
+
+        public static void main(String[] args)
+        {
+            RunTest(new HMacDrbgTest());
+        }
+
+        [Test]
+        public void HMacDrbgTestFunction()
+        {
+            string resultText = Perform().ToString();
+
+            Assert.AreEqual(Name + ": Okay", resultText);
+        }
+
+        private DRBGTestVector[] createTestVectorData()
+        {
+            return new DRBGTestVector[]
+                {
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    false,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "5A7D3B449F481CB38DF79AD2B1FCC01E57F8135E8C0B22CD0630BFB0127FB5408C8EFC17A929896E",
+                            "82cf772ec3e84b00fc74f5df104efbfb2428554e9ce367d03aeade37827fa8e9cb6a08196115d948"
+                        }),
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    false,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "B3BD05246CBA12A64735A4E3FDE599BC1BE30F439BD060208EEA7D71F9D123DF47B3CE069D98EDE6",
+                            "B5DADA380E2872DF935BCA55B882C8C9376902AB639765472B71ACEBE2EA8B1B6B49629CB67317E0"
+                        })
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F606162636465666768696A6B6C6D6E6F70717273747576"),
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    false,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "C7AAAC583C6EF6300714C2CC5D06C148CFFB40449AD0BB26FAC0497B5C57E161E36681BCC930CE80",
+                            "6EBD2B7B5E0A2AD7A24B1BF9A1DBA47D43271719B9C37B7FE81BA94045A14A7CB514B446666EA5A7"
+                        })
+                .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F808182838485868788898A8B8C8D8E8F90919293949596")
+                .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6"),
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    true,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "FEC4597F06A3A8CC8529D59557B9E661053809C0BC0EFC282ABD87605CC90CBA9B8633DCB1DAE02E",
+                            "84ADD5E2D2041C01723A4DE4335B13EFDF16B0E51A0AD39BD15E862E644F31E4A2D7D843E57C5968"
+                        }),
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    true,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "6C37FDD729AA40F80BC6AB08CA7CC649794F6998B57081E4220F22C5C283E2C91B8E305AB869C625",
+                            "CAF57DCFEA393B9236BF691FA456FEA7FDF1DF8361482CA54D5FA723F4C88B4FA504BF03277FA783"
+                        })
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F606162636465666768696A6B6C6D6E6F70717273747576"),
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    true,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "A1BA8FA58BB5013F43F7B6ED52B4539FA16DC77957AEE815B9C07004C7E992EB8C7E591964AFEEA2",
+                            "84264A73A818C95C2F424B37D3CC990B046FB50C2DC64A164211889A010F2471A0912FFEA1BF0195"
+                        })
+                    .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F808182838485868788898A8B8C8D8E8F90919293949596")
+                    .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6"),
+                new DRBGTestVector(
+                    new Sha256Digest(),
+                    new SHA256EntropyProvider().Get(440),
+                    false,
+                    "2021222324252627",
+                    128,
+                    new String[]
+                        {
+                            "D67B8C1734F46FA3F763CF57C6F9F4F2" +
+                                "DC1089BD8BC1F6F023950BFC5617635208C8501238AD7A44" +
+                                "00DEFEE46C640B61AF77C2D1A3BFAA90EDE5D207406E5403",
+                            "8FDAEC20F8B421407059E3588920DA7E" +
+                                "DA9DCE3CF8274DFA1C59C108C1D0AA9B0FA38DA5C792037C" +
+                                "4D33CD070CA7CD0C5608DBA8B885654639DE2187B74CB263"
+                        }),
+                new DRBGTestVector(
+                    new Sha256Digest(),
+                    new SHA256EntropyProvider().Get(440),
+                    true,
+                    "2021222324252627",
+                    128,
+                    new String[]
+                        {
+                            "FABD0AE25C69DC2EFDEFB7F20C5A31B5" +
+                            "7AC938AB771AA19BF8F5F1468F665C938C9A1A5DF0628A56" +
+                            "90F15A1AD8A613F31BBD65EEAD5457D5D26947F29FE91AA7",
+                            "6BD925B0E1C232EFD67CCD84F722E927" +
+                            "ECB46AB2B740014777AF14BA0BBF53A45BDBB62B3F7D0B9C" +
+                            "8EEAD057C0EC754EF8B53E60A1F434F05946A8B686AFBC7A"
+                        }),
+                new DRBGTestVector(
+                    new Sha384Digest(),
+                    new SHA384EntropyProvider().Get(888),
+                    false,
+                    "202122232425262728292A2B",
+                    192,
+                    new String[]{
+                        "03AB8BCE4D1DBBB636C5C5B7E1C58499FEB1C619CDD11D35" +
+                        "CD6CF6BB8F20EF27B6F5F9054FF900DB9EBF7BF30ED4DCBB" +
+                        "BC8D5B51C965EA226FFEE2CA5AB2EFD00754DC32F357BF7A" +
+                        "E42275E0F7704DC44E50A5220AD05AB698A22640AC634829",
+                        "B907E77144FD55A54E9BA1A6A0EED0AAC780020C41A15DD8" +
+                        "9A6C163830BA1D094E6A17100FF71EE30A96E1EE04D2A966" +
+                        "03832A4E404F1966C2B5F4CB61B9927E8D12AC1E1A24CF23" +
+                        "88C14E8EC96C35181EAEE32AAA46330DEAAFE5E7CE783C74"})
+                    .setPersonalizationString(
+                        "404142434445464748494A4B4C4D4E" +
+                        "4F505152535455565758595A5B5C5D5E5F60616263646566" +
+                        "6768696A6B6C6D6E6F707172737475767778797A7B7C7D7E" +
+                        "7F808182838485868788898A8B8C8D8E8F90919293949596" +
+                        "9798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAE"),
+                new DRBGTestVector(
+                    new Sha384Digest(),
+                    new SHA384EntropyProvider().Get(888),
+                    true,
+                    "202122232425262728292A2B",
+                    192,
+                    new String[]{
+                        "804A3AD720F4FCE8738D0632514FEF16430CB7D63A8DF1A5" +
+                        "F02A3CE3BD7ED6A668B69E63E2BB93F096EE753D6194A0F1" +
+                        "A32711063653009636337D22167CC4402D019AC216FA574F" +
+                        "091CF6EA283568D737A77BE38E8F09382C69E76B142ABC3A",
+                        "73B8E55C753202176A17B9B9754A9FE6F23B01861FCD4059" +
+                        "6AEAA301AF1AEF8AF0EAF22FBF34541EFFAB1431666ACACC" +
+                        "759338C7E28672819D53CFEF10A3E19DAFBD53295F1980A9" +
+                        "F491504A2725506784B7AC826D92C838A8668171CAAA86E7"})
+                    .setPersonalizationString(
+                        "404142434445464748494A4B4C4D4E" +
+                            "4F505152535455565758595A5B5C5D5E5F60616263646566" +
+                            "6768696A6B6C6D6E6F707172737475767778797A7B7C7D7E" +
+                            "7F808182838485868788898A8B8C8D8E8F90919293949596" +
+                            "9798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAE"),
+                new DRBGTestVector(
+                    new Sha512Digest(),
+                    new SHA512EntropyProvider().Get(888),
+                    false,
+                    "202122232425262728292A2B2C2D2E2F",
+                    256,
+                    new String[]{
+                        "2A5FF6520C20F66E" +
+                            "D5EA431BD4AEAC58F975EEC9A015137D5C94B73AA09CB8B5" +
+                            "9D611DDEECEB34A52BB999424009EB9EAC5353F92A6699D2" +
+                            "0A02164EEBBC6492941E10426323898465DFD731C7E04730" +
+                            "60A5AA8973841FDF3446FB6E72A58DA8BDA2A57A36F3DD98" +
+                            "6DF85C8A5C6FF31CDE660BF8A841B21DD6AA9D3AC356B87B",
+                        "0EDC8D7D7CEEC7FE" +
+                            "36333FB30C0A9A4B27AA0BECBF075568B006C1C3693B1C29" +
+                            "0F84769C213F98EB5880909EDF068FDA6BFC43503987BBBD" +
+                            "4FC23AFBE982FE4B4B007910CC4874EEC217405421C8D8A1" +
+                            "BA87EC684D0AF9A6101D9DB787AE82C3A6A25ED478DF1B12" +
+                            "212CEC325466F3AC7C48A56166DD0B119C8673A1A9D54F67"})
+                    .setPersonalizationString(
+                        "404142434445464748494A4B4C4D4E" +
+                            "4F505152535455565758595A5B5C5D5E5F60616263646566" +
+                            "6768696A6B6C6D6E6F707172737475767778797A7B7C7D7E" +
+                            "7F808182838485868788898A8B8C8D8E8F90919293949596" +
+                            "9798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAE"),
+                new DRBGTestVector(
+                    new Sha512Digest(),
+                    new SHA512EntropyProvider().Get(888),
+                    true,
+                    "202122232425262728292A2B2C2D2E2F",
+                    256,
+                    new String[]{
+                        "AAE4DC3C9ECC74D9" +
+                        "061DD527117EF3D29E1E52B26853C539D6CA797E8DA3D0BB" +
+                        "171D8E30B8B194D8C28F7F6BE3B986B88506DC6A01B294A7" +
+                        "165DD1C3470F7BE7B396AA0DB7D50C4051E7C7E1C8A7D21A" +
+                        "2B5878C0BCB163CAA79366E7A1162FDC88429616CD3E6977" +
+                        "8D327520A6BBBF71D8AA2E03EC4A9DAA0E77CF93E1EE30D2 ",
+                        "129FF6D31A23FFBC" +
+                        "870632B35EE477C2280DDD2ECDABEDB900C78418BE2D243B" +
+                        "B9D8E5093ECE7B6BF48638D8F704D134ADDEB7F4E9D5C142" +
+                        "CD05683E72B516486AF24AEC15D61E81E270DD4EBED91B62" +
+                        "12EB8896A6250D5C8BC3A4A12F7E3068FBDF856F47EB23D3" +
+                        "79F82C1EBCD1585FB260B9C0C42625FBCEE68CAD773CD5B1"})
+                .setPersonalizationString(
+                    "404142434445464748494A4B4C4D4E" +
+                        "4F505152535455565758595A5B5C5D5E5F60616263646566" +
+                        "6768696A6B6C6D6E6F707172737475767778797A7B7C7D7E" +
+                        "7F808182838485868788898A8B8C8D8E8F90919293949596" +
+                        "9798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAE"),
+                new DRBGTestVector(
+                    new Sha512Digest(),
+                    new SHA512EntropyProvider().Get(888),
+                    false,
+                    "202122232425262728292A2B2C2D2E2F",
+                    256,
+                    new String[]{
+                        "7AE31A2DEC31075F" +
+                        "E5972660C16D22ECC0D415C5693001BE5A468B590BC1AE2C" +
+                        "43F647F8D681AEEA0D87B79B0B4E5D089CA2C9D327534234" +
+                        "0254E6B04690D77A71A294DA9568479EEF8BB2A2110F18B6" +
+                        "22F60F35235DE0E8F9D7E98105D84AA24AF0757AF005DFD5" +
+                        "2FA51DE3F44FCE0C5F3A27FCE8B0F6E4A3F7C7B53CE34A3D",
+                        "D83A8084630F286D" +
+                        "A4DB49B9F6F608C8993F7F1397EA0D6F4A72CF3EF2733A11" +
+                        "AB823C29F2EBDEC3EDE962F93D920A1DB59C84E1E879C29F" +
+                        "5F9995FC3A6A3AF9B587CA7C13EA197D423E81E1D6469942" +
+                        "B6E2CA83A97E91F6B298266AC148A1809776C26AF5E239A5" +
+                        "5A2BEB9E752203A694E1F3FE2B3E6A0C9C314421CDB55FBD "})
+                .setPersonalizationString(
+                    "404142434445464748494A4B4C4D4E" +
+                    "4F505152535455565758595A5B5C5D5E5F60616263646566" +
+                    "6768696A6B6C6D6E6F707172737475767778797A7B7C7D7E" +
+                    "7F808182838485868788898A8B8C8D8E8F90919293949596" +
+                    "9798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAE")
+                .addAdditionalInput(
+                    "606162636465666768696A6B6C6D6E" +
+                    "6F707172737475767778797A7B7C7D7E7F80818283848586" +
+                    "8788898A8B8C8D8E8F909192939495969798999A9B9C9D9E" +
+                    "9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6" +
+                    "B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCE")
+                .addAdditionalInput(
+                    "A0A1A2A3A4A5A6A7A8A9AAABACADAE" +
+                    "AFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6" +
+                    "C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDE" +
+                    "DFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6" +
+                    "F7F8F9FAFBFCFDFEFF000102030405060708090A0B0C0D0E"),
+                new DRBGTestVector(
+                    new Sha512Digest(),
+                    new SHA512EntropyProvider().Get(888),
+                    true,
+                    "202122232425262728292A2B2C2D2E2F",
+                    256,
+                    new String[]{
+                        "28FD6060C4F35F4D" +
+                            "317AB2060EE32019E0DAA330F3F5650BBCA57CB67EE6AF1C" +
+                            "6F25D1B01F3601EDA85DC2ED29A9B2BA4C85CF491CE7185F" +
+                            "1A2BD9378AE3C655BD1CEC2EE108AE7FC382989F6D4FEA8A" +
+                            "B01499697C2F07945CE02C5ED617D04287FEAF3BA638A4CE" +
+                            "F3BB6B827E40AF16279580FCF1FDAD830930F7FDE341E2AF",
+                        "C0B1601AFE39338B" +
+                            "58DC2BE7C256AEBE3C21C5A939BEEC7E97B3528AC420F0C6" +
+                            "341847187666E0FF578A8EB0A37809F877365A28DF2FA0F0" +
+                            "6354A6F02496747369375B9A9D6B756FDC4A8FB308E08256" +
+                            "9D79A85BB960F747256626389A3B45B0ABE7ECBC39D5CD7B" +
+                            "2C18DF2E5FDE8C9B8D43474C54B6F9839468445929B438C7"}),
+                new DRBGTestVector(
+                    new Sha512Digest(),
+                    new SHA512EntropyProvider().Get(888),
+                    true,
+                    "202122232425262728292A2B2C2D2E2F",
+                    256,
+                    new String[]{
+                        "72691D2103FB567C" +
+                        "CD30370715B36666F63430087B1C688281CA0974DB456BDB" +
+                        "A7EB5C48CFF62EA05F9508F3B530CE995A272B11EC079C13" +
+                        "923EEF8E011A93C19B58CC6716BC7CB8BD886CAA60C14D85" +
+                        "C023348BD77738C475D6C7E1D9BFF4B12C43D8CC73F838DC" +
+                        "4F8BD476CF8328EEB71B3D873D6B7B859C9B21065638FF95",
+                        "8570DA3D47E1E160" +
+                        "5CF3E44B8D328B995EFC64107B6292D1B1036B5F88CE3160" +
+                        "2F12BEB71D801C0942E7C0864B3DB67A9356DB203490D881" +
+                        "24FE86BCE38AC2269B4FDA6ABAA884039DF80A0336A24D79" +
+                        "1EB3067C8F5F0CF0F18DD73B66A7B316FB19E02835CC6293" +
+                        "65FCD1D3BE640178ED9093B91B36E1D68135F2785BFF505C"})
+                .addAdditionalInput(
+                    "606162636465666768696A6B6C6D6E" +
+                    "6F707172737475767778797A7B7C7D7E7F80818283848586" +
+                    "8788898A8B8C8D8E8F909192939495969798999A9B9C9D9E" +
+                    "9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6" +
+                    "B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCE")
+                .addAdditionalInput(
+                    "A0A1A2A3A4A5A6A7A8A9AAABACADAE" +
+                    "AFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6" +
+                    "C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDE" +
+                    "DFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6" +
+                    "F7F8F9FAFBFCFDFEFF000102030405060708090A0B0C0D0E"),
+                new DRBGTestVector(
+                    new Sha512Digest(),
+                    new SHA512EntropyProvider().Get(888),
+                    true,
+                    "202122232425262728292A2B2C2D2E2F",
+                    256,
+                    new String[]{
+                        "AAE4DC3C9ECC74D9" +
+                        "061DD527117EF3D29E1E52B26853C539D6CA797E8DA3D0BB" +
+                        "171D8E30B8B194D8C28F7F6BE3B986B88506DC6A01B294A7" +
+                        "165DD1C3470F7BE7B396AA0DB7D50C4051E7C7E1C8A7D21A" +
+                        "2B5878C0BCB163CAA79366E7A1162FDC88429616CD3E6977" +
+                        "8D327520A6BBBF71D8AA2E03EC4A9DAA0E77CF93E1EE30D2 ",
+                        "129FF6D31A23FFBC" +
+                        "870632B35EE477C2280DDD2ECDABEDB900C78418BE2D243B" +
+                        "B9D8E5093ECE7B6BF48638D8F704D134ADDEB7F4E9D5C142" +
+                        "CD05683E72B516486AF24AEC15D61E81E270DD4EBED91B62" +
+                        "12EB8896A6250D5C8BC3A4A12F7E3068FBDF856F47EB23D3" +
+                        "79F82C1EBCD1585FB260B9C0C42625FBCEE68CAD773CD5B1"})
+                .setPersonalizationString(
+                    "404142434445464748494A4B4C4D4E" +
+                        "4F505152535455565758595A5B5C5D5E5F60616263646566" +
+                        "6768696A6B6C6D6E6F707172737475767778797A7B7C7D7E" +
+                        "7F808182838485868788898A8B8C8D8E8F90919293949596" +
+                        "9798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAE"),
+                new DRBGTestVector(
+                    new Sha512Digest(),
+                    new SHA512EntropyProvider().Get(888),
+                    true,
+                    "202122232425262728292A2B2C2D2E2F",
+                    256,
+                    new String[]{
+                        "B8E827652175E6E0" +
+                        "6E513C7BE94B5810C14ED94AD903647940CAEB7EE014C848" +
+                        "8DCBBE6D4D6616D06656A3DC707CDAC4F02EE6D8408C065F" +
+                        "CB068C0760DA47C5D60E5D70D09DC3929B6979615D117F7B" +
+                        "EDCC661A98514B3A1F55B2CBABDCA59F11823E4838065F1F" +
+                        "8431CBF28A577738234AF3F188C7190CC19739E72E9BBFFF",
+                        "7ED41B9CFDC8C256" +
+                        "83BBB4C553CC2DC61F690E62ABC9F038A16B8C519690CABE" +
+                        "BD1B5C196C57CF759BB9871BE0C163A57315EA96F615136D" +
+                        "064572F09F26D659D24211F9610FFCDFFDA8CE23FFA96735" +
+                        "7595182660877766035EED800B05364CE324A75EB63FD9B3" +
+                        "EED956D147480B1D0A42DF8AA990BB628666F6F61D60CBE2"})
+                .setPersonalizationString(
+                    "404142434445464748494A4B4C4D4E" +
+                        "4F505152535455565758595A5B5C5D5E5F60616263646566" +
+                        "6768696A6B6C6D6E6F707172737475767778797A7B7C7D7E" +
+                        "7F808182838485868788898A8B8C8D8E8F90919293949596" +
+                        "9798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAE")
+                .addAdditionalInput(
+                    "606162636465666768696A6B6C6D6E" +
+                        "6F707172737475767778797A7B7C7D7E7F80818283848586" +
+                        "8788898A8B8C8D8E8F909192939495969798999A9B9C9D9E" +
+                        "9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6" +
+                        "B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCE")
+                .addAdditionalInput(
+                    "A0A1A2A3A4A5A6A7A8A9AAABACADAE" +
+                    "AFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6" +
+                    "C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDE" +
+                    "DFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6" +
+                    "F7F8F9FAFBFCFDFEFF000102030405060708090A0B0C0D0E")
+                };
+        }
+
+        public override void PerformTest()
+        {
+            DRBGTestVector[] tests = createTestVectorData();
+            SP80090Drbg d;
+
+            for (int i = 0; i != tests.Length; i++)
+            {
+                DRBGTestVector tv = tests[i];
+
+                byte[] nonce = tv.nonce();
+                byte[] personalisationString = tv.personalizationString();
+
+                d = new HMacSP800Drbg(new HMac(tv.getDigest()), tv.securityStrength(), tv.entropySource(), personalisationString, nonce);
+
+                byte[] output = new byte[tv.expectedValue(0).Length];
+
+                d.Generate(output, tv.additionalInput(0), tv.predictionResistance());
+
+                byte[] expected = tv.expectedValue(0);
+
+                if (!AreEqual(expected, output))
+                {
+                    Fail("Test #" + (i + 1) + ".1 failed, expected " + Hex.ToHexString(tv.expectedValue(0)) + " got " + Hex.ToHexString(output));
+                }
+
+                output = new byte[tv.expectedValue(0).Length];
+
+                d.Generate(output, tv.additionalInput(1), tv.predictionResistance());
+
+                expected = tv.expectedValue(1);
+                if (!AreEqual(expected, output))
+                {
+                    Fail("Test #" + (i + 1) + ".2 failed, expected " + Hex.ToHexString(tv.expectedValue(1)) + " got " + Hex.ToHexString(output));
+                }
+            }
+
+            // Exception tests
+            //
+            try
+            {
+                d = new HMacSP800Drbg(new HMac(new Sha256Digest()), 256, new SHA256EntropyProvider().Get(128), null, null);
+                Fail("no exception thrown");
+            }
+            catch (ArgumentException e)
+            {
+                if (!e.Message.Equals("Not enough entropy for security strength required"))
+                {
+                    Fail("Wrong exception", e);
+                }
+            }
+        }
+
+        private class SHA1EntropyProvider : TestEntropySourceProvider
+        {
+            internal SHA1EntropyProvider() : base(
+                    Hex.Decode(
+                        "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F30313233343536"
+                            + "808182838485868788898A8B8C8D8E8F909192939495969798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6"
+                            + "C0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6"), true)
+            {
+            }
+        }
+
+        internal class SHA256EntropyProvider : TestEntropySourceProvider
+        {
+            internal SHA256EntropyProvider() : base(Hex.Decode(
+                    "00010203040506" +
+                        "0708090A0B0C0D0E0F101112131415161718191A1B1C1D1E" +
+                        "1F202122232425262728292A2B2C2D2E2F30313233343536" +
+                        "80818283848586" +
+                        "8788898A8B8C8D8E8F909192939495969798999A9B9C9D9E" +
+                        "9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6" +
+                        "C0C1C2C3C4C5C6" +
+                        "C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDE" +
+                        "DFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6"), true)
+            {
+            }
+        }
+
+        internal class SHA384EntropyProvider : TestEntropySourceProvider
+        {
+            internal SHA384EntropyProvider() : base(Hex.Decode(
+                    "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F20212223242526"
+                        + "2728292A2B2C2D2E2F303132333435363738393A3B3C3D3E3F404142434445464748494A4B4C4D4E4F50515253545556"
+                        + "5758595A5B5C5D5E5F606162636465666768696A6B6C6D6E" +
+                        "808182838485868788898A8B8C8D8E" +
+                        "8F909192939495969798999A9B9C9D9E9FA0A1A2A3A4A5A6" +
+                        "A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBE" +
+                        "BFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6" +
+                        "D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6E7E8E9EAEBECEDEE" +
+                        "C0C1C2C3C4C5C6C7C8C9CACBCCCDCE" +
+                        "CFD0D1D2D3D4D5D6D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6" +
+                        "E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6F7F8F9FAFBFCFDFE" +
+                        "FF000102030405060708090A0B0C0D0E0F10111213141516" +
+                        "1718191A1B1C1D1E1F202122232425262728292A2B2C2D2E"), true)
+            { }
+        }
+
+        internal class SHA512EntropyProvider : TestEntropySourceProvider
+        {
+            internal SHA512EntropyProvider() :
+                base(Hex.Decode(
+                    "000102030405060708090A0B0C0D0E" +
+                        "0F101112131415161718191A1B1C1D1E1F20212223242526" +
+                        "2728292A2B2C2D2E2F303132333435363738393A3B3C3D3E" +
+                        "3F404142434445464748494A4B4C4D4E4F50515253545556" +
+                        "5758595A5B5C5D5E5F606162636465666768696A6B6C6D6E" +
+                        "808182838485868788898A8B8C8D8E" +
+                        "8F909192939495969798999A9B9C9D9E9FA0A1A2A3A4A5A6" +
+                        "A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBE" +
+                        "BFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6" +
+                        "D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6E7E8E9EAEBECEDEE" +
+                        "C0C1C2C3C4C5C6C7C8C9CACBCCCDCE" +
+                        "CFD0D1D2D3D4D5D6D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6" +
+                        "E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6F7F8F9FAFBFCFDFE" +
+                        "FF000102030405060708090A0B0C0D0E0F10111213141516" +
+                        "1718191A1B1C1D1E1F202122232425262728292A2B2C2D2E"), true)
+            {
+            }
+        }
+    }
+}
diff --git a/crypto/test/src/crypto/prng/test/HashDrbgTest.cs b/crypto/test/src/crypto/prng/test/HashDrbgTest.cs
new file mode 100644
index 000000000..d9776e0d6
--- /dev/null
+++ b/crypto/test/src/crypto/prng/test/HashDrbgTest.cs
@@ -0,0 +1,471 @@
+using System;
+
+using Org.BouncyCastle.Crypto.Digests;
+using Org.BouncyCastle.Crypto.Prng.Drbg;
+using Org.BouncyCastle.Utilities.Test;
+using Org.BouncyCastle.Utilities.Encoders;
+using NUnit.Framework;
+
+namespace Org.BouncyCastle.Crypto.Prng.Test
+{
+    /**
+     * DRBG Test
+     */
+    [TestFixture]
+    public class HashDrbgTest: SimpleTest
+    {
+        public override String Name
+    {
+            get
+            {
+                return "HashDRBG";
+            }
+        }
+
+        public static void main(String[] args)
+    {
+            RunTest(new HashDrbgTest());
+        }
+
+        private DRBGTestVector[] createTestVectorData()
+    {
+            return new DRBGTestVector[]
+                {
+                new DRBGTestVector(
+                            new Sha1Digest(),
+                            new SHA1EntropyProvider().Get(440),
+                            false,
+                            "2021222324",
+                            80,
+                            new String[]
+                                {
+                                    "9F7CFF1ECA23E750F66326969F11800F12088BA68E441D15D888B3FE12BF66FE057494F4546DE2F1",
+                                    "B77AA5C0CD55BBCEED7574AF223AFD988C7EEC8EFF4A94E5E89D26A04F58FA79F5E0D3702D7A9A6A"
+                                }
+                        ),
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    false,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "AB438BD3B01A0AF85CFEE29F7D7B71621C4908B909124D430E7B406FB1086EA994C582E0D656D989",
+                            "29D9098F987E7005314A0F51B3DD2B8122F4AED706735DE6AD5DDBF223177C1E5F3AEBC52FAB90B9"
+                        })
+                    .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F606162636465666768696A6B6C6D6E6F70717273747576"),
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    false,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "E76B4EDD5C865BC8AFD809A59B69B429AC7F4352A579BCF3F75E56249A3491F87C3CA6848B0FAB25",
+                            "6577B6B4F87A93240B199FE51A3B335313683103DECE171E3256FB7E803586CA4E45DD242EB01F70"
+                        })
+                    .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F808182838485868788898A8B8C8D8E8F90919293949596")
+                    .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6"),
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    true,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "56EF4913373994D5539F4D7D17AFE7448CDF5E72416CC6A71A340059FA0D5AE526B23250C46C0944",
+                            "575B37A2739814F966C63B60A2C4F149CA9ACC84FC4B25493289B085C67B2E30F5F0B99A2C349E2A"
+                        }),
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    true,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "532CA1165DCFF21C55592687639884AF4BC4B057DF8F41DE653AB44E2ADEC7C9303E75ABE277EDBF",
+                            "73C2C67C696D686D0C4DBCEB5C2AF7DDF6F020B6874FAE4390F102117ECAAFF54418529A367005A0"
+                        })
+                .setPersonalizationString("404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F606162636465666768696A6B6C6D6E6F70717273747576"),
+                new DRBGTestVector(
+                    new Sha1Digest(),
+                    new SHA1EntropyProvider().Get(440),
+                    true,
+                    "2021222324",
+                    80,
+                    new String[]
+                        {
+                            "183C242A1430E46C4ED70B4DBE1BF9AB0AB8721CDCA2A2D1820AD6F6C956858543B2AA191D8D1287",
+                            "F196F9BD021C745CBD5AC7BFCE48EAAF0D0E7C091FBF436940E63A198EE770D9A4F0718669AF2BC9"
+                        })
+                    .addAdditionalInput("606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F808182838485868788898A8B8C8D8E8F90919293949596")
+                    .addAdditionalInput("A0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6"),
+                new DRBGTestVector(
+                    new Sha256Digest(),
+                    new SHA256EntropyProvider().Get(440),
+                    false,
+                    "2021222324252627",
+                    128,
+                    new String[]
+                        {
+                            "77E05A0E7DC78AB5D8934D5E93E82C06" +
+                            "A07C04CEE6C9C53045EEB485872777CF3B3E35C474F976B8" +
+                            "94BF301A86FA651F463970E89D4A0534B2ECAD29EC044E7E",
+                            "5FF4BA493C40CFFF3B01E472C575668C" +
+                            "CE3880B9290B05BFEDE5EC96ED5E9B2898508B09BC800EEE" +
+                            "099A3C90602ABD4B1D4F343D497C6055C87BB956D53BF351"
+                        }
+                ),
+                new DRBGTestVector(
+                    new Sha256Digest(),
+                    new SHA256EntropyProvider().Get(440),
+                    true,
+                    "2021222324252627",
+                    128,
+                    new String[]
+                        {
+                            "92275523C70E567BCF9B35EC50B933F8" +
+                            "12616DF586B7F72EE1BC7735A5C2654373CBBC72316DFF84" +
+                            "20A33BF02B97AC8D1952583F270ACD7005CC027F4CF1187E",
+                            "681A46B2AA8694A0FE4DEEA720927A84" +
+                            "EAAA985E59C19F8BE0984D8CBEF8C69B754167641946E040" +
+                            "EE2043E1CCB29DCF063C0A50830E428E6DCA262ECD77C542"
+                        }),
+                new DRBGTestVector(
+                            new Sha384Digest(),
+                            new SHA384EntropyProvider().Get(888),
+                            false,
+                            "202122232425262728292A2B",
+                            192,
+                            new String[]
+                                {
+                                    "04FF23AD15E78790ADD36B438BBC097C7A11747CC2CCEEDE" +
+                                    "2C978B23B3DC63B732C953061D7764990ABFEFC47A581B92" +
+                                    "1BC0428C4F12212460E406A0F0651E7F0CB9A90ABFDB07B5" +
+                                    "25565C74F0AA085082F6CF213AAFAD0C0646895078F1E1FE",
+                                    "4F35B85F95DEE3E873054905CFD02341653E18F529930CBE" +
+                                    "14D909F37FEAF2C790D22FAE7516B4590BE35D53E2FE1A35" +
+                                    "AFE4B6607CB358589C3B4D094A1D81FE0717F1DF5BDDEB3E" +
+                                    "114F130BB781E66C22B5B770E8AE115FF39F8ADAF66DEEDF"
+                                }
+                        ),
+                new DRBGTestVector(
+                        new Sha384Digest(),
+                        new SHA384EntropyProvider().Get(888),
+                        true,
+                        "202122232425262728292A2B",
+                        192,
+                        new String[]
+                            {
+                                "97993B78F7C31C0E876DC92EB7D6C408E09D608AD6B99D0E" +
+                                "A2229B05A578C426334FCC8A1C7E676ED2D89A5B4CDF5B3F" +
+                                "4ADF11936BF14F4E10909DBA9C24F4FDFFDE72351DA8E2CC" +
+                                "3B135A395373899E5F1A5955B880CA9B9E9DD4C9CA7FA4D4",
+                                "F5983946320E36C64EF283CA1F65D197CF81624EC6778E77" +
+                                "0E78949D84EF21A45CDD62D1DB76920D4C2836FC6AE5299F" +
+                                "AF1357D9701FAD10FBD88D1E2832239436D76EB271BDC3CA" +
+                                "04425EC88BC0E89A4D5C37FFCE7C6C3ABDE9C413AE6D3FEA"
+                            }
+                    ),
+                new DRBGTestVector(
+                            new Sha512Digest(),
+                            new SHA512EntropyProvider().Get(888),
+                            false,
+                            "202122232425262728292A2B2C2D2E2F",
+                            256,
+                            new String[]
+                            {
+                                "DA126CF95C6BF97E" +
+                                "2F731F2137A907ACC70FD7AC9EBACD1C6E31C74029B052E3" +
+                                "AABC48F3B00993F2B2381F7650A55322A968C86E05DE88E6" +
+                                "367F6EF89A601DB4342E9086C7AC13B5E56C32E9E668040B" +
+                                "73847893C5BFD38A1CF44F348B4EEE4CD68ADB7E7B8C837F" +
+                                "19BC4F902761F7CFF24AB1D704FD11C4E929D8553753B55D",
+                                "400B977CE8A2BB6A" +
+                                "84C6FD1CF901459685ABF5408CFF4588CEDF52E2D2DC300A" +
+                                "A9B4FAED8CD0161C2172B1FD269253195883D6EBF21020F2" +
+                                "C20E5F2C81AE60C8595B834A229B1F5B726C1125717E6207" +
+                                "8886EF38E61E32707AD5F8116C6393DFB6E7C7AE0E8E92BB" +
+                                "D7E0C3D04BBA02F5169F2F569A58158915FEE4C9D28D45DB"
+                            }
+                        )
+                    .setPersonalizationString(
+                        "404142434445464748494A4B4C4D4E" +
+                        "4F505152535455565758595A5B5C5D5E5F60616263646566" +
+                        "6768696A6B6C6D6E6F707172737475767778797A7B7C7D7E" +
+                        "7F808182838485868788898A8B8C8D8E8F90919293949596" +
+                        "9798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAE")
+                    .addAdditionalInput(
+                        "606162636465666768696A6B6C6D6E" +
+                        "6F707172737475767778797A7B7C7D7E7F80818283848586" +
+                        "8788898A8B8C8D8E8F909192939495969798999A9B9C9D9E" +
+                        "9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6" +
+                        "B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCE")
+                    .addAdditionalInput(
+                        "A0A1A2A3A4A5A6A7A8A9AAABACADAE" +
+                        "AFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6" +
+                        "C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDE" +
+                        "DFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6" +
+                        "F7F8F9FAFBFCFDFEFF000102030405060708090A0B0C0D0E"),
+                new DRBGTestVector(
+                        new Sha512Digest(),
+                        new SHA512EntropyProvider().Get(888),
+                        true,
+                        "202122232425262728292A2B2C2D2E2F",
+                        256,
+                        new String[]
+                        {
+                            "F93CA6855590A77F" +
+                            "07354097E90E026648B6115DF008FFEDBD9D9811F54E8286" +
+                            "EF00FDD6BA1E58DF2535E3FBDD9A9BA3754A97F36EE83322" +
+                            "1582060A1F37FCE4EE8826636B28EAD589593F4CA8B64738" +
+                            "8F24EB3F0A34796968D21BDEE6F81FD5DF93536F935937B8" +
+                            "025EC8CBF57DDB0C61F2E41463CC1516D657DA2829C6BF90",
+                            "4817618F48C60FB1" +
+                            "CE5BFBDA0CAF4591882A31F6EE3FE0F78779992A06EC60F3" +
+                            "7FB9A8D6108C231F0A927754B0599FA4FA27A4E25E065EF0" +
+                            "3085B892979DC0E7A1080883CAEBFDFD3665A8F2D061C521" +
+                            "F7D6E3DA2AF8B97B6B43B6EC831AF515070A83BBB9AC95ED" +
+                            "4EF49B756A2377A5F0833D847E27A88DDB0C2CE4AD782E7B "
+                        }
+                    ),
+                new DRBGTestVector(
+                        new Sha512Digest(),
+                        new SHA512EntropyProvider().Get(888),
+                        true,
+                        "202122232425262728292A2B2C2D2E2F",
+                        256,
+                        new String[]
+                        {
+                            "0455DD4AD7DBACB2" +
+                            "410BE58DF7248D765A4547ABAEE1743B0BCAD37EBD06DA7C" +
+                            "F7CE5E2216E525327E9E2005EBEF2CE53BD733B18128627D" +
+                            "3FD6153089373AF2606A1584646A0EA488BFEF45228699A0" +
+                            "89CEA8AEC44502D86D9591F3552C688B7F7B45FCB0C3C2B9" +
+                            "43C1CD8A6FC63DF4D81C3DA543C9CF2843855EA84E4F959C",
+                            "C047D46D7F614E4E" +
+                            "4A7952C79A451F8F7ACA379967E2977C401C626A2ED70D74" +
+                            "A63660579A354115BC8C8C8CC3AEA3050686A0CFCDB6FA9C" +
+                            "F78D4C2165BAF851C6F9B1CD16A2E14C15C6DAAC56C16E75" +
+                            "FC84A14D58B41622E88B0F1B1995587FD8BAA999CBA98025" +
+                            "4C8AB9A9691DF7B84D88B639A9A3106DEABEB63748B99C09"
+                        }
+                    )
+                .addAdditionalInput(
+                    "606162636465666768696A6B6C6D6E" +
+                    "6F707172737475767778797A7B7C7D7E7F80818283848586" +
+                    "8788898A8B8C8D8E8F909192939495969798999A9B9C9D9E" +
+                    "9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6" +
+                    "B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCE")
+                .addAdditionalInput(
+                    "A0A1A2A3A4A5A6A7A8A9AAABACADAE" +
+                    "AFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6" +
+                    "C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDE" +
+                    "DFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6" +
+                    "F7F8F9FAFBFCFDFEFF000102030405060708090A0B0C0D0E"),
+                new DRBGTestVector(
+                            new Sha512Digest(),
+                            new SHA512EntropyProvider().Get(888),
+                            true,
+                            "202122232425262728292A2B2C2D2E2F",
+                            256,
+                            new String[]
+                            {
+                                "22EB93A67911DA73" +
+                                "85D9180C78127DE1A04FF713114C07C9C615F7CC5EF72744" +
+                                "A2DDCD7C3CB85E65DED8EF5F240FBDCBEBBDE2BAAC8ECF7D" +
+                                "CBC8AC333E54607AD41DC495D83DF72A05EF55B127C1441C" +
+                                "9A0EFFDA2C7954DB6C2D04342EB812E5E0B11D6C395F41ED" +
+                                "A2702ECE5BA479E2DFA18F953097492636C12FE30CE5C968",
+                                "E66698CFBF1B3F2E" +
+                                "919C03036E584EAA81CF1C6666240AF05F70637043733954" +
+                                "D8A1E5A66A04C53C6900FDC145D4A3A80A31F5868ACE9AC9" +
+                                "4E14E2051F624A05EEA1F8B684AA5410BCE315E76EA07C71" +
+                                "5D6F34731320FF0DCF78D795E6EFA2DF92B98BE636CDFBA2" +
+                                "9008DD392112AEC202F2E481CB9D83F987FEA69CD1B368BB"
+                            }
+                        )
+                    .setPersonalizationString(
+                        "404142434445464748494A4B4C4D4E" +
+                            "4F505152535455565758595A5B5C5D5E5F60616263646566" +
+                            "6768696A6B6C6D6E6F707172737475767778797A7B7C7D7E" +
+                            "7F808182838485868788898A8B8C8D8E8F90919293949596" +
+                            "9798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAE"),
+                new DRBGTestVector(
+                            new Sha512Digest(),
+                            new SHA512EntropyProvider().Get(888),
+                            true,
+                            "202122232425262728292A2B2C2D2E2F",
+                            256,
+                            new String[]
+                            {
+                                "7596A76372308BD5" +
+                                "A5613439934678B35521A94D81ABFE63A21ACF61ABB88B61" +
+                                "E86A12C37F308F2BBBE32BE4B38D03AE808386494D70EF52" +
+                                "E9E1365DD18B7784CAB826F31D47579E4D57F69D8BF3152B" +
+                                "95741946CEBE58571DF58ED39980D9AF44E69F01E8989759" +
+                                "8E40171101A0E3302838E0AD9E849C01988993CF9F6E5263",
+                                "DBE5EE36FCD85301" +
+                                "303E1C3617C1AC5E23C08885D0BEFAAD0C85A0D89F85B9F1" +
+                                "6ECE3D88A24EB96504F2F13EFA7049621782F5DE2C416A0D" +
+                                "294CCFE53545C4E309C48E1E285A2B829A574B72B3C2FBE1" +
+                                "34D01E3706B486F2401B9820E17298A342666918E15B8462" +
+                                "87F8C5AF2D96B20FAF3D0BB392E15F4A06CDB0DECD1B6AD7"
+                            }
+                        )
+                    .setPersonalizationString(
+                        "404142434445464748494A4B4C4D4E" +
+                            "4F505152535455565758595A5B5C5D5E5F60616263646566" +
+                            "6768696A6B6C6D6E6F707172737475767778797A7B7C7D7E" +
+                            "7F808182838485868788898A8B8C8D8E8F90919293949596" +
+                            "9798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAE")
+                    .addAdditionalInput(
+                        "606162636465666768696A6B6C6D6E" +
+                            "6F707172737475767778797A7B7C7D7E7F80818283848586" +
+                            "8788898A8B8C8D8E8F909192939495969798999A9B9C9D9E" +
+                            "9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6" +
+                            "B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCE")
+                    .addAdditionalInput(
+                        "A0A1A2A3A4A5A6A7A8A9AAABACADAE" +
+                            "AFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6" +
+                            "C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDE" +
+                            "DFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6" +
+                            "F7F8F9FAFBFCFDFEFF000102030405060708090A0B0C0D0E")
+                };
+        }
+
+        public override void PerformTest()
+        {
+            DRBGTestVector[] tests = createTestVectorData();
+            SP80090Drbg d;
+
+            for (int i = 0; i != tests.Length; i++)
+            {
+                DRBGTestVector tv = tests[i];
+
+                byte[] nonce = tv.nonce();
+                byte[] personalisationString = tv.personalizationString();
+
+                d = new HashSP800Drbg(tv.getDigest(), tv.securityStrength(), tv.entropySource(), personalisationString, nonce);
+
+                byte[] output = new byte[tv.expectedValue(0).Length];
+
+                d.Generate(output, tv.additionalInput(0), tv.predictionResistance());
+
+                byte[] expected = tv.expectedValue(0);
+
+                if (!AreEqual(expected, output))
+                {
+                    Fail("Test #" + (i + 1) + ".1 failed, expected " + Hex.ToHexString(tv.expectedValue(0)) + " got " + Hex.ToHexString(output));
+                }
+
+                output = new byte[tv.expectedValue(0).Length];
+
+                d.Generate(output, tv.additionalInput(1), tv.predictionResistance());
+
+                expected = tv.expectedValue(1);
+                if (!AreEqual(expected, output))
+                {
+                    Fail("Test #" + (i + 1) + ".2 failed, expected " + Hex.ToHexString(tv.expectedValue(1)) + " got " + Hex.ToHexString(output));
+                }
+            }
+
+            // Exception tests
+            //
+            try
+            {
+                d = new HashSP800Drbg(new Sha256Digest(), 256, new SHA256EntropyProvider().Get(128), null, null);
+                Fail("no exception thrown");
+            }
+            catch (ArgumentException e)
+            {
+                if (!e.Message.Equals("Not enough entropy for security strength required"))
+                {
+                    Fail("Wrong exception", e);
+                }
+            }
+
+            try
+            {
+                d = new HashSP800Drbg(new Sha1Digest(), 256, new SHA256EntropyProvider().Get(256), null, null);
+                Fail("no exception thrown");
+            }
+            catch (ArgumentException e)
+            {
+                if (!e.Message.Equals("Requested security strength is not supported by the derivation function"))
+                {
+                    Fail("Wrong exception", e);
+                }
+            }
+        }
+
+    internal class SHA1EntropyProvider: TestEntropySourceProvider
+    {
+        internal SHA1EntropyProvider(): base(
+                Hex.Decode(
+                    "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F30313233343536"
+                        + "808182838485868788898A8B8C8D8E8F909192939495969798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6"
+                        + "C0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6"), true)
+        {}
+    }
+
+    internal class SHA256EntropyProvider: TestEntropySourceProvider
+    {
+        internal SHA256EntropyProvider(): base(Hex.Decode(
+                "00010203040506" +
+                    "0708090A0B0C0D0E0F101112131415161718191A1B1C1D1E" +
+                    "1F202122232425262728292A2B2C2D2E2F30313233343536" +
+                    "80818283848586" +
+                    "8788898A8B8C8D8E8F909192939495969798999A9B9C9D9E" +
+                    "9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6" +
+                    "C0C1C2C3C4C5C6" +
+                    "C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDE" +
+                    "DFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6"), true)
+        { }
+    }
+
+    internal class SHA384EntropyProvider: TestEntropySourceProvider
+    {
+        internal SHA384EntropyProvider(): base(Hex.Decode(
+                "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F20212223242526"
+                    + "2728292A2B2C2D2E2F303132333435363738393A3B3C3D3E3F404142434445464748494A4B4C4D4E4F50515253545556"
+                    + "5758595A5B5C5D5E5F606162636465666768696A6B6C6D6E" +
+                    "808182838485868788898A8B8C8D8E" +
+                    "8F909192939495969798999A9B9C9D9E9FA0A1A2A3A4A5A6" +
+                    "A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBE" +
+                    "BFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6" +
+                    "D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6E7E8E9EAEBECEDEE" +
+                    "C0C1C2C3C4C5C6C7C8C9CACBCCCDCE" +
+                    "CFD0D1D2D3D4D5D6D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6" +
+                    "E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6F7F8F9FAFBFCFDFE" +
+                    "FF000102030405060708090A0B0C0D0E0F10111213141516" +
+                    "1718191A1B1C1D1E1F202122232425262728292A2B2C2D2E"), true)
+        {}
+    }
+
+    internal class SHA512EntropyProvider: TestEntropySourceProvider
+    {
+        internal SHA512EntropyProvider(): base(Hex.Decode(
+                "000102030405060708090A0B0C0D0E" +
+                    "0F101112131415161718191A1B1C1D1E1F20212223242526" +
+                    "2728292A2B2C2D2E2F303132333435363738393A3B3C3D3E" +
+                    "3F404142434445464748494A4B4C4D4E4F50515253545556" +
+                    "5758595A5B5C5D5E5F606162636465666768696A6B6C6D6E" +
+                    "808182838485868788898A8B8C8D8E" +
+                    "8F909192939495969798999A9B9C9D9E9FA0A1A2A3A4A5A6" +
+                    "A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBE" +
+                    "BFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6" +
+                    "D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6E7E8E9EAEBECEDEE" +
+                    "C0C1C2C3C4C5C6C7C8C9CACBCCCDCE" +
+                    "CFD0D1D2D3D4D5D6D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6" +
+                    "E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6F7F8F9FAFBFCFDFE" +
+                    "FF000102030405060708090A0B0C0D0E0F10111213141516" +
+                    "1718191A1B1C1D1E1F202122232425262728292A2B2C2D2E"), true)
+        { }
+    }
+}
+}
diff --git a/crypto/test/src/crypto/prng/test/TestEntropySourceProvider.cs b/crypto/test/src/crypto/prng/test/TestEntropySourceProvider.cs
new file mode 100644
index 000000000..a37bcd844
--- /dev/null
+++ b/crypto/test/src/crypto/prng/test/TestEntropySourceProvider.cs
@@ -0,0 +1,64 @@
+using System;
+
+namespace Org.BouncyCastle.Crypto.Prng.Test
+{
+    public class TestEntropySourceProvider: IEntropySourceProvider
+    {
+        private readonly byte[] data;
+        private readonly bool isPredictionResistant;
+
+        internal TestEntropySourceProvider(byte[] data, bool isPredictionResistant)
+        {
+            this.data = data;
+            this.isPredictionResistant = isPredictionResistant;
+        }
+
+        public IEntropySource Get(int bitsRequired)
+        {
+            return new EntropySource(bitsRequired, data, isPredictionResistant);
+        }
+
+        internal class EntropySource: IEntropySource
+        {
+            private readonly int bitsRequired;
+            private readonly byte[] data;
+            private readonly bool isPredictionResistant;
+
+            int index = 0;
+
+            internal EntropySource(int bitsRequired, byte[] data, bool isPredictionResistant)
+            {
+                this.bitsRequired = bitsRequired;
+                this.data = data;
+                this.isPredictionResistant = isPredictionResistant;
+            }
+
+            public bool IsPredictionResistant
+            {
+                get
+                {
+                    return isPredictionResistant;
+                }
+            }
+
+            public byte[] GetEntropy()
+            {
+                byte[] rv = new byte[bitsRequired / 8];
+
+                Array.Copy(data, index, rv, 0, rv.Length);
+
+                index += bitsRequired / 8;
+
+                return rv;
+            }
+
+            public int EntropySize
+            {
+                get
+                {
+                    return bitsRequired;
+                }
+            }
+    }
+}
+}