/// <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();
}
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);
}
