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2004-11-10 jrandom

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* Allow loading the (mini)streaming connection options from the
      environment.
    * More defensive programming in the DSA implementation.
This commit is contained in:
jrandom
2004-11-10 12:33:01 +00:00
committed by zzz
parent ffc405138d
commit 881524a5e4
4 changed files with 88 additions and 37 deletions
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62
core/java/src/net/i2p/crypto/DSAEngine.java
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@ -57,37 +57,41 @@ public class DSAEngine {
public boolean verifySignature(Signature signature, byte signedData[], int offset, int size, SigningPublicKey verifyingKey) {
long start = _context.clock().now();
byte[] sigbytes = signature.getData();
byte rbytes[] = new byte[20];
byte sbytes[] = new byte[20];
for (int x = 0; x < 40; x++) {
if (x < 20) {
rbytes[x] = sigbytes[x];
} else {
sbytes[x - 20] = sigbytes[x];
try {
byte[] sigbytes = signature.getData();
byte rbytes[] = new byte[20];
byte sbytes[] = new byte[20];
for (int x = 0; x < 40; x++) {
if (x < 20) {
rbytes[x] = sigbytes[x];
} else {
sbytes[x - 20] = sigbytes[x];
}
}
BigInteger s = new NativeBigInteger(1, sbytes);
BigInteger r = new NativeBigInteger(1, rbytes);
BigInteger y = new NativeBigInteger(1, verifyingKey.getData());
BigInteger w = s.modInverse(CryptoConstants.dsaq);
byte data[] = calculateHash(signedData, offset, size).getData();
NativeBigInteger bi = new NativeBigInteger(1, data);
BigInteger u1 = bi.multiply(w).mod(CryptoConstants.dsaq);
BigInteger u2 = r.multiply(w).mod(CryptoConstants.dsaq);
BigInteger modval = CryptoConstants.dsag.modPow(u1, CryptoConstants.dsap);
BigInteger modmulval = modval.multiply(y.modPow(u2,CryptoConstants.dsap));
BigInteger v = (modmulval).mod(CryptoConstants.dsap).mod(CryptoConstants.dsaq);
boolean ok = v.compareTo(r) == 0;
long diff = _context.clock().now() - start;
if (diff > 1000) {
if (_log.shouldLog(Log.WARN))
_log.warn("Took too long to verify the signature (" + diff + "ms)");
}
return ok;
} catch (Exception e) {
_log.log(Log.CRIT, "Error verifying the signature", e);
return false;
}
BigInteger s = new NativeBigInteger(1, sbytes);
BigInteger r = new NativeBigInteger(1, rbytes);
BigInteger y = new NativeBigInteger(1, verifyingKey.getData());
BigInteger w = s.modInverse(CryptoConstants.dsaq);
byte data[] = calculateHash(signedData, offset, size).getData();
NativeBigInteger bi = new NativeBigInteger(1, data);
BigInteger u1 = bi.multiply(w).mod(CryptoConstants.dsaq);
BigInteger u2 = r.multiply(w).mod(CryptoConstants.dsaq);
BigInteger modval = CryptoConstants.dsag.modPow(u1, CryptoConstants.dsap);
BigInteger modmulval = modval.multiply(y.modPow(u2,CryptoConstants.dsap));
BigInteger v = (modmulval).mod(CryptoConstants.dsap).mod(CryptoConstants.dsaq);
boolean ok = v.compareTo(r) == 0;
long diff = _context.clock().now() - start;
if (diff > 1000) {
if (_log.shouldLog(Log.WARN))
_log.warn("Took too long to verify the signature (" + diff + "ms)");
}
return ok;
}
public Signature sign(byte data[], SigningPrivateKey signingKey) {