/**
* To save from Attacks on Parameter Authentication one can send hash of parameters to other party
*
* @return byte[] of what???
*/
@Override
public byte[] getParametersHash() {
byte[] parms = NativeLib.getECParameters(ecGroup);
SHA1 sha1 = new SHA1(BLOCK_SIZE);
sha1.update(parms, 0, parms.length);
sha1.generate();
byte[] digest = sha1.getDigest();
return digest;
}
@Override
public boolean checkParametersHash(byte[] hash) {
if (hash == null || hash.length != BLOCK_SIZE) return false;
byte[] parms = NativeLib.getECParameters(ecGroup);
SHA1 sha1 = new SHA1(BLOCK_SIZE);
sha1.update(parms, 0, parms.length);
sha1.generate();
byte[] digest = sha1.getDigest();
for (int i = 0; i < digest.length; i++) if (digest[i] != hash[i]) return false;
return true;
}
/**
* Runs an integrity test.
*
* @return true: selftest passed / false: selftest failed
*/
public boolean selfTest() {
int nI;
SHA1 tester;
byte[] digest;
tester = new SHA1();
tester.update(SELFTEST_MESSAGE);
tester.finalize();
digest = tester.getDigest();
for (nI = 0; nI < DIGEST_SIZE; nI++) {
if (digest[nI] != SELFTEST_DIGEST[nI]) {
return false;
}
}
return true;
}