public static void crypto_sign2(
byte[] sig, int sigoffset,
byte[] m, int moffset, int mlen,
byte[] sk, int skoffset)
{
byte[] az = new byte[64];
byte[] r = new byte[64];
byte[] hram = new byte[64];
GroupElementP3 R;
var hasher2 = new Sha3Digest(512);
{
hasher2.BlockUpdate(sk, 0, 32);
hasher2.DoFinal(az, 0);
ScalarOperations.sc_clamp(az, 0);
hasher2.Reset();
hasher2.BlockUpdate(az, 32, 32);
hasher2.BlockUpdate(m, moffset, mlen);
hasher2.DoFinal(r, 0);
ScalarOperations.sc_reduce(r);
GroupOperations.ge_scalarmult_base(out R, r, 0);
GroupOperations.ge_p3_tobytes(sig, sigoffset, ref R);
hasher2.Reset();
hasher2.BlockUpdate(sig, sigoffset, 32);
hasher2.BlockUpdate(sk, skoffset + 32, 32);
hasher2.BlockUpdate(m, moffset, mlen);
hasher2.DoFinal(hram, 0);
ScalarOperations.sc_reduce(hram);
var s = new byte[32];
Array.Copy(sig, sigoffset + 32, s, 0, 32);
ScalarOperations.sc_muladd(s, hram, az, r);
Array.Copy(s, 0, sig, sigoffset + 32, 32);
CryptoBytes.Wipe(s);
}
}
public static bool crypto_sign_verify(
byte[] sig, int sigoffset,
byte[] m, int moffset, int mlen,
byte[] pk, int pkoffset)
{
byte[] checkr = new byte[32];
GroupElementP3 A;
GroupElementP2 R;
if ((sig[sigoffset + 63] & 224) != 0)
{
return(false);
}
if (GroupOperations.ge_frombytes_negate_vartime(out A, pk, pkoffset) != 0)
{
return(false);
}
var hash = new Sha3Digest(512);
hash.BlockUpdate(sig, sigoffset, 32);
hash.BlockUpdate(pk, pkoffset, 32);
hash.BlockUpdate(m, moffset, mlen);
var b = new byte[64];
hash.DoFinal(b, 0);
ScalarOperations.sc_reduce(b);
var sm32 = new byte[32];//todo: remove allocation
Array.Copy(sig, sigoffset + 32, sm32, 0, 32);
GroupOperations.ge_double_scalarmult_vartime(out R, b, ref A, sm32);
GroupOperations.ge_tobytes(checkr, 0, ref R);
var result = CryptoBytes.ConstantTimeEquals(checkr, 0, sig, sigoffset, 32);
CryptoBytes.Wipe(b);
CryptoBytes.Wipe(checkr);
return(result);
}
internal static void crypto_sign_keypair(byte[] pk, int pkoffset, byte[] sk, int skoffset, byte[] seed,
int seedoffset)
{
GroupElementP3 A;
int i;
Array.Copy(seed, seedoffset, sk, skoffset, 32);
var digest = new Sha3Digest(512); //new // tried and failed -> new Sha3Digest(512);
var h = new byte[64]; // byte[] ha = Sha512.Hash(sk, skoffset, 32);//ToDo: REMOVE alloc
digest.BlockUpdate(sk, skoffset, 32); // new
digest.DoFinal(h, 0); // new
ScalarOperations.sc_clamp(h, 0);
GroupOperations.ge_scalarmult_base(out A, h, 0);
GroupOperations.ge_p3_tobytes(pk, pkoffset, ref A);
for (i = 0; i < 32; ++i)
{
sk[skoffset + 32 + i] = pk[pkoffset + i];
}
CryptoBytes.Wipe(h);
}
