diff options
Diffstat (limited to 'Crypto/src/crypto/agreement/kdf')
| -rw-r--r-- | Crypto/src/crypto/agreement/kdf/DHKdfParameters.cs | 57 | ||||
| -rw-r--r-- | Crypto/src/crypto/agreement/kdf/DHKekGenerator.cs | 129 | ||||
| -rw-r--r-- | Crypto/src/crypto/agreement/kdf/ECDHKekGenerator.cs | 71 |
3 files changed, 257 insertions, 0 deletions
diff --git a/Crypto/src/crypto/agreement/kdf/DHKdfParameters.cs b/Crypto/src/crypto/agreement/kdf/DHKdfParameters.cs new file mode 100644 index 000000000..f6c9e6079 --- /dev/null +++ b/Crypto/src/crypto/agreement/kdf/DHKdfParameters.cs @@ -0,0 +1,57 @@ +using System; + +using Org.BouncyCastle.Asn1; + +namespace Org.BouncyCastle.Crypto.Agreement.Kdf +{ + public class DHKdfParameters + : IDerivationParameters + { + private readonly DerObjectIdentifier algorithm; + private readonly int keySize; + private readonly byte[] z; + private readonly byte[] extraInfo; + + public DHKdfParameters( + DerObjectIdentifier algorithm, + int keySize, + byte[] z) + : this(algorithm, keySize, z, null) + { + } + + public DHKdfParameters( + DerObjectIdentifier algorithm, + int keySize, + byte[] z, + byte[] extraInfo) + { + this.algorithm = algorithm; + this.keySize = keySize; + this.z = z; // TODO Clone? + this.extraInfo = extraInfo; + } + + public DerObjectIdentifier Algorithm + { + get { return algorithm; } + } + + public int KeySize + { + get { return keySize; } + } + + public byte[] GetZ() + { + // TODO Clone? + return z; + } + + public byte[] GetExtraInfo() + { + // TODO Clone? + return extraInfo; + } + } +} diff --git a/Crypto/src/crypto/agreement/kdf/DHKekGenerator.cs b/Crypto/src/crypto/agreement/kdf/DHKekGenerator.cs new file mode 100644 index 000000000..fa2921539 --- /dev/null +++ b/Crypto/src/crypto/agreement/kdf/DHKekGenerator.cs @@ -0,0 +1,129 @@ +using System; + +using Org.BouncyCastle.Asn1; + +namespace Org.BouncyCastle.Crypto.Agreement.Kdf +{ + /** + * RFC 2631 Diffie-hellman KEK derivation function. + */ + public class DHKekGenerator + : IDerivationFunction + { + private readonly IDigest digest; + + private DerObjectIdentifier algorithm; + private int keySize; + private byte[] z; + private byte[] partyAInfo; + + public DHKekGenerator( + IDigest digest) + { + this.digest = digest; + } + + public void Init( + IDerivationParameters param) + { + DHKdfParameters parameters = (DHKdfParameters)param; + + this.algorithm = parameters.Algorithm; + this.keySize = parameters.KeySize; + this.z = parameters.GetZ(); // TODO Clone? + this.partyAInfo = parameters.GetExtraInfo(); // TODO Clone? + } + + public IDigest Digest + { + get { return digest; } + } + + public int GenerateBytes( + byte[] outBytes, + int outOff, + int len) + { + if ((outBytes.Length - len) < outOff) + { + throw new DataLengthException("output buffer too small"); + } + + long oBytes = len; + int outLen = digest.GetDigestSize(); + + // + // this is at odds with the standard implementation, the + // maximum value should be hBits * (2^32 - 1) where hBits + // is the digest output size in bits. We can't have an + // array with a long index at the moment... + // + if (oBytes > ((2L << 32) - 1)) + { + throw new ArgumentException("Output length too large"); + } + + int cThreshold = (int)((oBytes + outLen - 1) / outLen); + + byte[] dig = new byte[digest.GetDigestSize()]; + + int counter = 1; + + for (int i = 0; i < cThreshold; i++) + { + digest.BlockUpdate(z, 0, z.Length); + + // KeySpecificInfo + DerSequence keyInfo = new DerSequence( + algorithm, + new DerOctetString(integerToBytes(counter))); + + // OtherInfo + Asn1EncodableVector v1 = new Asn1EncodableVector(keyInfo); + + if (partyAInfo != null) + { + v1.Add(new DerTaggedObject(true, 0, new DerOctetString(partyAInfo))); + } + + v1.Add(new DerTaggedObject(true, 2, new DerOctetString(integerToBytes(keySize)))); + + byte[] other = new DerSequence(v1).GetDerEncoded(); + + digest.BlockUpdate(other, 0, other.Length); + + digest.DoFinal(dig, 0); + + if (len > outLen) + { + Array.Copy(dig, 0, outBytes, outOff, outLen); + outOff += outLen; + len -= outLen; + } + else + { + Array.Copy(dig, 0, outBytes, outOff, len); + } + + counter++; + } + + digest.Reset(); + + return len; + } + + private byte[] integerToBytes( + int keySize) + { + byte[] val = new byte[4]; + + val[0] = (byte)(keySize >> 24); + val[1] = (byte)(keySize >> 16); + val[2] = (byte)(keySize >> 8); + val[3] = (byte)keySize; + + return val; + } + } +} diff --git a/Crypto/src/crypto/agreement/kdf/ECDHKekGenerator.cs b/Crypto/src/crypto/agreement/kdf/ECDHKekGenerator.cs new file mode 100644 index 000000000..7d55aa485 --- /dev/null +++ b/Crypto/src/crypto/agreement/kdf/ECDHKekGenerator.cs @@ -0,0 +1,71 @@ +using System; + +using Org.BouncyCastle.Asn1; +using Org.BouncyCastle.Asn1.X509; +using Org.BouncyCastle.Crypto.Generators; +using Org.BouncyCastle.Crypto.Parameters; + +namespace Org.BouncyCastle.Crypto.Agreement.Kdf +{ + /** + * X9.63 based key derivation function for ECDH CMS. + */ + public class ECDHKekGenerator + : IDerivationFunction + { + private readonly IDerivationFunction kdf; + + private DerObjectIdentifier algorithm; + private int keySize; + private byte[] z; + + public ECDHKekGenerator( + IDigest digest) + { + this.kdf = new Kdf2BytesGenerator(digest); + } + + public void Init( + IDerivationParameters param) + { + DHKdfParameters parameters = (DHKdfParameters)param; + + this.algorithm = parameters.Algorithm; + this.keySize = parameters.KeySize; + this.z = parameters.GetZ(); // TODO Clone? + } + + public IDigest Digest + { + get { return kdf.Digest; } + } + + public int GenerateBytes( + byte[] outBytes, + int outOff, + int len) + { + // TODO Create an ASN.1 class for this (RFC3278) + // ECC-CMS-SharedInfo + DerSequence s = new DerSequence( + new AlgorithmIdentifier(algorithm, DerNull.Instance), + new DerTaggedObject(true, 2, new DerOctetString(integerToBytes(keySize)))); + + kdf.Init(new KdfParameters(z, s.GetDerEncoded())); + + return kdf.GenerateBytes(outBytes, outOff, len); + } + + private byte[] integerToBytes(int keySize) + { + byte[] val = new byte[4]; + + val[0] = (byte)(keySize >> 24); + val[1] = (byte)(keySize >> 16); + val[2] = (byte)(keySize >> 8); + val[3] = (byte)keySize; + + return val; + } + } +} |