Plz be more specific:
Which input to the signing method are you changing? Can you give some code?
Something like that: static byte[] sign(byte[] message, String secretPhrase) {
try {
byte[] P = new byte[32];
byte[] s = new byte[32];
MessageDigest digest = MessageDigest.getInstance("SHA-256");
Curve25519.keygen(P, s, digest.digest(secretPhrase.getBytes("UTF-8")));
byte[] m = digest.digest(message);
digest.update(m);
//byte[] x = digest.digest(s); digest.update(s);
byte[] x = digest.digest(nonce);
byte[] Y = new byte[32];
Curve25519.keygen(Y, null, x);
digest.update(m);
byte[] h = digest.digest(Y);
byte[] v = new byte[32];
Curve25519.sign(v, h, x, s);
byte[] signature = new byte[64];
System.arraycopy(v, 0, signature, 0, 32);
System.arraycopy(h, 0, signature, 32, 32);
return signature;
} catch (Exception e) {
return null;
}
}
Edit: I'm not sure this code is correct, though. Better read about "ephemeral" keys, how they r generated.
