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Diffstat (limited to '')
| -rw-r--r-- | Crypto/src/crypto/macs/GOST28147Mac.cs | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/Crypto/src/crypto/macs/GOST28147Mac.cs b/Crypto/src/crypto/macs/GOST28147Mac.cs new file mode 100644 index 000000000..9a8f1b730 --- /dev/null +++ b/Crypto/src/crypto/macs/GOST28147Mac.cs @@ -0,0 +1,296 @@ +using System; + +using Org.BouncyCastle.Crypto; +using Org.BouncyCastle.Crypto.Parameters; + +namespace Org.BouncyCastle.Crypto.Macs +{ + /** + * implementation of GOST 28147-89 MAC + */ + public class Gost28147Mac : IMac + { + private const int blockSize = 8; + private const int macSize = 4; + private int bufOff; + private byte[] buf; + private byte[] mac; + private bool firstStep = true; + private int[] workingKey; + + // + // This is default S-box - E_A. + private byte[] S = + { + 0x9,0x6,0x3,0x2,0x8,0xB,0x1,0x7,0xA,0x4,0xE,0xF,0xC,0x0,0xD,0x5, + 0x3,0x7,0xE,0x9,0x8,0xA,0xF,0x0,0x5,0x2,0x6,0xC,0xB,0x4,0xD,0x1, + 0xE,0x4,0x6,0x2,0xB,0x3,0xD,0x8,0xC,0xF,0x5,0xA,0x0,0x7,0x1,0x9, + 0xE,0x7,0xA,0xC,0xD,0x1,0x3,0x9,0x0,0x2,0xB,0x4,0xF,0x8,0x5,0x6, + 0xB,0x5,0x1,0x9,0x8,0xD,0xF,0x0,0xE,0x4,0x2,0x3,0xC,0x7,0xA,0x6, + 0x3,0xA,0xD,0xC,0x1,0x2,0x0,0xB,0x7,0x5,0x9,0x4,0x8,0xF,0xE,0x6, + 0x1,0xD,0x2,0x9,0x7,0xA,0x6,0x0,0x8,0xC,0x4,0x5,0xF,0x3,0xB,0xE, + 0xB,0xA,0xF,0x5,0x0,0xC,0xE,0x8,0x6,0x2,0x3,0x9,0x1,0x7,0xD,0x4 + }; + + public Gost28147Mac() + { + mac = new byte[blockSize]; + buf = new byte[blockSize]; + bufOff = 0; + } + + private static int[] generateWorkingKey( + byte[] userKey) + { + if (userKey.Length != 32) + throw new ArgumentException("Key length invalid. Key needs to be 32 byte - 256 bit!!!"); + + int[] key = new int[8]; + for(int i=0; i!=8; i++) + { + key[i] = bytesToint(userKey,i*4); + } + + return key; + } + + public void Init( + ICipherParameters parameters) + { + Reset(); + buf = new byte[blockSize]; + if (parameters is ParametersWithSBox) + { + ParametersWithSBox param = (ParametersWithSBox)parameters; + + // + // Set the S-Box + // + param.GetSBox().CopyTo(this.S, 0); + + // + // set key if there is one + // + if (param.Parameters != null) + { + workingKey = generateWorkingKey(((KeyParameter)param.Parameters).GetKey()); + } + } + else if (parameters is KeyParameter) + { + workingKey = generateWorkingKey(((KeyParameter)parameters).GetKey()); + } + else + { + throw new ArgumentException("invalid parameter passed to Gost28147 init - " + + parameters.GetType().Name); + } + } + + public string AlgorithmName + { + get { return "Gost28147Mac"; } + } + + public int GetMacSize() + { + return macSize; + } + + private int gost28147_mainStep(int n1, int key) + { + int cm = (key + n1); // CM1 + + // S-box replacing + + int om = S[ 0 + ((cm >> (0 * 4)) & 0xF)] << (0 * 4); + om += S[ 16 + ((cm >> (1 * 4)) & 0xF)] << (1 * 4); + om += S[ 32 + ((cm >> (2 * 4)) & 0xF)] << (2 * 4); + om += S[ 48 + ((cm >> (3 * 4)) & 0xF)] << (3 * 4); + om += S[ 64 + ((cm >> (4 * 4)) & 0xF)] << (4 * 4); + om += S[ 80 + ((cm >> (5 * 4)) & 0xF)] << (5 * 4); + om += S[ 96 + ((cm >> (6 * 4)) & 0xF)] << (6 * 4); + om += S[112 + ((cm >> (7 * 4)) & 0xF)] << (7 * 4); + +// return om << 11 | om >>> (32-11); // 11-leftshift + int omLeft = om << 11; + int omRight = (int)(((uint) om) >> (32 - 11)); // Note: Casts required to get unsigned bit rotation + + return omLeft | omRight; + } + + private void gost28147MacFunc( + int[] workingKey, + byte[] input, + int inOff, + byte[] output, + int outOff) + { + int N1, N2, tmp; //tmp -> for saving N1 + N1 = bytesToint(input, inOff); + N2 = bytesToint(input, inOff + 4); + + for (int k = 0; k < 2; k++) // 1-16 steps + { + for (int j = 0; j < 8; j++) + { + tmp = N1; + N1 = N2 ^ gost28147_mainStep(N1, workingKey[j]); // CM2 + N2 = tmp; + } + } + + intTobytes(N1, output, outOff); + intTobytes(N2, output, outOff + 4); + } + + //array of bytes to type int + private static int bytesToint( + byte[] input, + int inOff) + { + return (int)((input[inOff + 3] << 24) & 0xff000000) + ((input[inOff + 2] << 16) & 0xff0000) + + ((input[inOff + 1] << 8) & 0xff00) + (input[inOff] & 0xff); + } + + //int to array of bytes + private static void intTobytes( + int num, + byte[] output, + int outOff) + { + output[outOff + 3] = (byte)(num >> 24); + output[outOff + 2] = (byte)(num >> 16); + output[outOff + 1] = (byte)(num >> 8); + output[outOff] = (byte)num; + } + + private static byte[] CM5func( + byte[] buf, + int bufOff, + byte[] mac) + { + byte[] sum = new byte[buf.Length - bufOff]; + + Array.Copy(buf, bufOff, sum, 0, mac.Length); + + for (int i = 0; i != mac.Length; i++) + { + sum[i] = (byte)(sum[i] ^ mac[i]); + } + + return sum; + } + + public void Update( + byte input) + { + if (bufOff == buf.Length) + { + byte[] sumbuf = new byte[buf.Length]; + Array.Copy(buf, 0, sumbuf, 0, mac.Length); + + if (firstStep) + { + firstStep = false; + } + else + { + sumbuf = CM5func(buf, 0, mac); + } + + gost28147MacFunc(workingKey, sumbuf, 0, mac, 0); + bufOff = 0; + } + + buf[bufOff++] = input; + } + + public void BlockUpdate( + byte[] input, + int inOff, + int len) + { + if (len < 0) + throw new ArgumentException("Can't have a negative input length!"); + + int gapLen = blockSize - bufOff; + + if (len > gapLen) + { + Array.Copy(input, inOff, buf, bufOff, gapLen); + + byte[] sumbuf = new byte[buf.Length]; + Array.Copy(buf, 0, sumbuf, 0, mac.Length); + + if (firstStep) + { + firstStep = false; + } + else + { + sumbuf = CM5func(buf, 0, mac); + } + + gost28147MacFunc(workingKey, sumbuf, 0, mac, 0); + + bufOff = 0; + len -= gapLen; + inOff += gapLen; + + while (len > blockSize) + { + sumbuf = CM5func(input, inOff, mac); + gost28147MacFunc(workingKey, sumbuf, 0, mac, 0); + + len -= blockSize; + inOff += blockSize; + } + } + + Array.Copy(input, inOff, buf, bufOff, len); + + bufOff += len; + } + + public int DoFinal( + byte[] output, + int outOff) + { + //padding with zero + while (bufOff < blockSize) + { + buf[bufOff++] = 0; + } + + byte[] sumbuf = new byte[buf.Length]; + Array.Copy(buf, 0, sumbuf, 0, mac.Length); + + if (firstStep) + { + firstStep = false; + } + else + { + sumbuf = CM5func(buf, 0, mac); + } + + gost28147MacFunc(workingKey, sumbuf, 0, mac, 0); + + Array.Copy(mac, (mac.Length/2)-macSize, output, outOff, macSize); + + Reset(); + + return macSize; + } + + public void Reset() + { + // Clear the buffer. + Array.Clear(buf, 0, buf.Length); + bufOff = 0; + + firstStep = true; + } + } +} |