internal static FieldZqElement GenerateChallenge(IssuerParameters ip, UProveToken upt, byte[] a, int pseudonymIndex, byte[] ap, GroupElement Ps, byte[] m, byte[] md, int[] disclosed, FieldZqElement[] disclosedX, int[] committed, CommitmentValues[] commitments, out byte[] mdPrime)
{
bool hasCommitments = (committed != null && committed.Length > 0);
if (hasCommitments)
{
if (committed.Length != commitments.Length)
{
throw new ArgumentException("Inconsistent committed indices and commitment values");
}
}
HashFunction hash = ip.HashFunction;
hash.Hash(ComputeTokenID(ip, upt));
hash.Hash(a);
hash.Hash(disclosed);
hash.Hash(disclosedX);
if (!hasCommitments)
{
hash.HashNull(); // C
hash.HashNull(); // < {tildeC} >
hash.HashNull(); // < {tildeA} >
}
else
{
hash.Hash(committed);
hash.Hash(commitments.Length); // length of < {tildeC} >
for (int i = 0; i < commitments.Length; i++)
{
hash.Hash(commitments[i].TildeC);
}
hash.Hash(commitments.Length); // length of < {tildeA} >
for (int i = 0; i < commitments.Length; i++)
{
hash.Hash(commitments[i].TildeA);
}
}
hash.Hash(pseudonymIndex == PresentationProof.DeviceAttributeIndex ? 0 : pseudonymIndex);
hash.Hash(ap);
hash.Hash(Ps);
hash.Hash(m);
mdPrime = hash.Digest;
if (upt.IsDeviceProtected)
{
hash = ip.HashFunction;
hash.Hash(md);
hash.Hash(mdPrime);
return(ip.Zq.GetElementFromDigest(hash.Digest));
}
else
{
return(ip.Zq.GetElementFromDigest(mdPrime));
}
}
public void HashFormattingTest()
{
HashFunction hash;
// byte
hash = new HashFunction(TestVectorData.HashVectors.UIDh);
byte b = 0x01;
hash.Hash(b);
Assert.IsTrue(HexToBytes(TestVectorData.HashVectors.hash_byte).SequenceEqual(hash.Digest), "hash_byte");
// octet string
hash = new HashFunction(TestVectorData.HashVectors.UIDh);
byte[] octetString = new byte[] { 0x01, 0x02, 0x03, 0x04, 0x05 };
hash.Hash(octetString);
Assert.IsTrue(HexToBytes(TestVectorData.HashVectors.hash_octetstring).SequenceEqual(hash.Digest), "hash_octetstring");
// null
hash = new HashFunction(TestVectorData.HashVectors.UIDh);
hash.HashNull();
Assert.IsTrue(HexToBytes(TestVectorData.HashVectors.hash_null).SequenceEqual(hash.Digest), "hash_null");
// list
hash = new HashFunction(TestVectorData.HashVectors.UIDh);
hash.Hash(3); // list length
hash.Hash(b);
hash.Hash(octetString);
hash.HashNull();
Assert.IsTrue(HexToBytes(TestVectorData.HashVectors.hash_list).SequenceEqual(hash.Digest), "hash_list");
// subgroup 1.3.6.1.4.1.311.75.1.1.1
hash = new HashFunction(TestVectorData.HashVectors.UIDh);
hash.Hash(SubgroupParameterSets.ParamSetL2048N256V1.Group);
Assert.IsTrue(HexToBytes(TestVectorData.HashVectors.hash_subgroup).SequenceEqual(hash.Digest), "hash_subgroup");
// ec group 1.3.6.1.4.1.311.75.1.2.1
hash = new HashFunction(TestVectorData.HashVectors.UIDh);
hash.Hash(ECParameterSets.ParamSet_EC_P256_V1.Group);
Assert.IsTrue(HexToBytes(TestVectorData.HashVectors.hash_ecgroup).SequenceEqual(hash.Digest), "hash_ecgroup");
}
