public static int uxed25519_sign(ISha512 sha512provider,
byte[] signature_out,
byte[] curve25519_privkey,
byte[] msg, int msg_len,
byte[] random)
{
// just return -1 as this shouldn't be used
return(-1);
byte[] a = new byte[32];
byte[] aneg = new byte[32];
byte[] A = new byte[32];
Ge_p3 Bu = new Ge_p3();
Ge_p3 ed_pubkey_point = new Ge_p3();
byte[] sigbuf = new byte[crypto_additions.MAX_MSG_LEN + 160]; /* working buffer */
byte sign_bit = 0;
if (msg_len > crypto_additions.MAX_MSG_LEN)
{
//memset(signature_out, 0, 96);
return(-1);
}
/* Convert the Curve25519 privkey to an Ed25519 public key */
Ge_scalarmult_base.ge_scalarmult_base(ed_pubkey_point, curve25519_privkey);
Ge_p3_tobytes.ge_p3_tobytes(A, ed_pubkey_point);
/* Force Edwards sign bit to zero */
sign_bit = (byte)((A[31] & 0x80) >> 7);
Array.Copy(curve25519_privkey, 0, a, 0, 32);
Sc_neg.sc_neg(aneg, a);
Sc_cmov.sc_cmov(a, aneg, sign_bit);
A[31] &= 0x7F;
//Elligator.calculate_Bv_and_V(sha512provider, Bu, signature_out, sigbuf, a, msg, msg_len);
/* Perform an Ed25519 signature with explicit private key */
usign_modified.crypto_usign_modified(sha512provider, sigbuf, msg, msg_len, a, A, random, Bu, signature_out /*U*/);
Array.Copy(sigbuf, 0, signature_out, 32, 64);
Zeroize.zeroize(a, 32);
return(0);
}
public static int xed25519_sign(ISha512 sha512provider,
byte[] signature_out,
byte[] curve25519_privkey,
byte[] msg, int msg_len,
byte[] random)
{
byte[] a = new byte[32];
byte[] A = new byte[32];
byte[] aneg = new byte[32];
Ge_p3 ed_pubkey_point = new Ge_p3();
// see link below
byte[] sigbuf = new byte[msg_len + 128]; /* working buffer */
byte sign_bit = 0;
// this should be different but whatever
// https://github.com/WhisperSystems/curve25519-java/commit/2f388f601afdac6a78a19ced2f0629da1ff9800f#diff-6e488e4e28814b3fa524b6781fcaf912R19
//if (msg_len > crypto_additions.MAX_MSG_LEN)
//{
// //memset(signature_out, 0, 64);
// return -1;
//}
/* Convert the Curve25519 privkey to an Ed25519 public key */
Ge_scalarmult_base.ge_scalarmult_base(ed_pubkey_point, curve25519_privkey);
Ge_p3_tobytes.ge_p3_tobytes(A, ed_pubkey_point);
/* Force Edwards sign bit to zero */
sign_bit = (byte)((A[31] & 0x80) >> 7);
Array.Copy(curve25519_privkey, 0, a, 0, 32);
Sc_neg.sc_neg(aneg, a);
Sc_cmov.sc_cmov(a, aneg, sign_bit);
A[31] &= 0x7F;
/* Perform an Ed25519 signature with explicit private key */
sign_modified.crypto_sign_modified(sha512provider, sigbuf, msg, msg_len, a, A, random);
Array.Copy(sigbuf, 0, signature_out, 0, 64);
Zeroize.zeroize(a, 32);
Zeroize.zeroize(aneg, 32);
return(0);
}