private void GetSymmetricKey()
{
var infoToWrite = GetInfoReady(this.merchantIdentifierField);
IDigest digest = new Sha256Digest();
this.symmetricKey = new byte[digest.GetDigestSize()];
digest.Update((byte)(1 >> 24));
digest.Update((byte)(1 >> 16));
digest.Update((byte)(1 >> 8));
digest.Update((byte)1);
digest.BlockUpdate(this.sharedSecret, 0, this.sharedSecret.Length);
digest.BlockUpdate(infoToWrite, 0, infoToWrite.Length);
digest.DoFinal(this.symmetricKey, 0);
}
private BigInteger SMPHash(byte hash_number, BigInteger big_int_a, BigInteger big_int_b)
{
byte[] _encoded_mpi = null;
Sha256Digest _sha256 = new Sha256Digest();
_sha256.Update(hash_number);
Utility.EncodeMpiBytes(big_int_a, ref _encoded_mpi);
_sha256.BlockUpdate(_encoded_mpi, 0, _encoded_mpi.Length);
if (big_int_b != null)
{
Utility.EncodeMpiBytes(big_int_b, ref _encoded_mpi);
_sha256.BlockUpdate(_encoded_mpi, 0, _encoded_mpi.Length);
}
byte[] _hashed_bytes = new byte[_sha256.GetDigestSize()];
_sha256.DoFinal(_hashed_bytes, 0);
return(new BigInteger(1, _hashed_bytes));
}
private void BuildFromSeed(byte[] seed)
{
if (seed.Length != M)
{
throw new CoseException("Incorrect seed length");
}
int keyCount = 1 << H;
int p = Constants.Values[(int)_lmotsType].p;
_x = new byte[keyCount][];
// Build LMS Private Key
for (int q = 0; q < keyCount; q++)
{
byte[] qBytes = u32str(q);
// Build LM-OTS private key for each leaf
_x[q] = new byte[M * p];
for (UInt16 j = 0; j < p; j++)
{
Sha256Digest h = new Sha256Digest();
h.BlockUpdate(Identifier, 0, Identifier.Length);
h.BlockUpdate(qBytes, 0, qBytes.Length);
h.BlockUpdate(u16str(j), 0, 2);
h.Update(0xff);
h.BlockUpdate(seed, 0, seed.Length);
h.DoFinal(_x[q], j * M);
}
}
// Derive the public key
ComputePublicKey();
}
/// <summary>
/// From a single given key create a hashname with the intermediate hashes of other keys
/// </summary>
/// <returns>The key.</returns>
/// <param name="csid">The identifier for the cipher set as a string.</param>
/// <param name="keyData">The key data for the given csid.</param>
/// <param name="intermediates">Intermediates.</param>
public static string FromKey(string csid, byte[] keyData, IDictionary <string, string> intermediates)
{
Sha256Digest digest = new Sha256Digest();
List <string> keys = new List <string>(intermediates.Keys);
keys.Add(csid);
keys.Sort();
int digestSize = digest.GetDigestSize();
byte[] outhash = null;
foreach (var key in keys)
{
if (outhash != null)
{
digest.BlockUpdate(outhash, 0, digestSize);
}
else
{
outhash = new byte[digestSize];
}
byte inByte;
try {
inByte = Convert.ToByte(key, 16);
} catch (FormatException) {
return(null);
} catch (OverflowException) {
return(null);
} catch (ArgumentException) {
return(null);
}
digest.Update(inByte);
digest.DoFinal(outhash, 0);
digest.Reset();
digest.BlockUpdate(outhash, 0, digestSize);
if (key == csid)
{
Sha256Digest keyDigest = new Sha256Digest();
keyDigest.BlockUpdate(keyData, 0, keyData.Length);
keyDigest.DoFinal(outhash, 0);
digest.BlockUpdate(outhash, 0, outhash.Length);
}
else
{
byte[] keyIntermediate = Base32Encoder.Decode(intermediates [key]);
digest.BlockUpdate(keyIntermediate, 0, keyIntermediate.Length);
}
digest.DoFinal(outhash, 0);
}
return(Base32Encoder.Encode(outhash).TrimEnd(trimChars).ToLower());
}
public static string FromKeys(IDictionary <string, string> publicKeys)
{
// You've gotta have some keys to hash!
if (publicKeys.Count <= 0)
{
return(null);
}
Sha256Digest digest = new Sha256Digest();
List <string> keys = new List <string>(publicKeys.Keys);
keys.Sort();
int digestSize = digest.GetDigestSize();
byte[] outhash = null;
foreach (var key in keys)
{
if (outhash != null)
{
digest.BlockUpdate(outhash, 0, digestSize);
}
else
{
outhash = new byte[digestSize];
}
byte inByte;
try {
inByte = Convert.ToByte(key, 16);
} catch (FormatException) {
return(null);
} catch (OverflowException) {
return(null);
} catch (ArgumentException) {
return(null);
}
digest.Update(inByte);
digest.DoFinal(outhash, 0);
digest.Reset();
digest.BlockUpdate(outhash, 0, digestSize);
byte[] keyData = Base32Encoder.Decode(publicKeys [key]);
Sha256Digest keyDigest = new Sha256Digest();
keyDigest.BlockUpdate(keyData, 0, keyData.Length);
keyDigest.DoFinal(outhash, 0);
digest.BlockUpdate(outhash, 0, outhash.Length);
digest.DoFinal(outhash, 0);
}
return(Base32Encoder.Encode(outhash).TrimEnd(trimChars).ToLower());
}