public virtual 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(Pack.UInt32_To_BE((uint)keySize)))); kdf.Init(new KdfParameters(z, s.GetDerEncoded())); return kdf.GenerateBytes(outBytes, outOff, len); }
public virtual 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()]; uint counter = 1; for (int i = 0; i < cThreshold; i++) { digest.BlockUpdate(z, 0, z.Length); // KeySpecificInfo DerSequence keyInfo = new DerSequence( algorithm, new DerOctetString(Pack.UInt32_To_BE(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(Pack.UInt32_To_BE((uint)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 (int)oBytes; }
public override Asn1Object ToAsn1Object() { DerSequence hashSeq = new DerSequence(datagroupHash); Asn1EncodableVector v = new Asn1EncodableVector(version, digestAlgorithmIdentifier, hashSeq); if (versionInfo != null) { v.Add(versionInfo); } return new DerSequence(v); }