what-the-bank/sources/org/bouncycastle/crypto/signers/DSASigner.java

96 lines
4.1 KiB
Java

package org.bouncycastle.crypto.signers;
import java.math.BigInteger;
import java.security.SecureRandom;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.DSA;
import org.bouncycastle.crypto.params.DSAKeyParameters;
import org.bouncycastle.crypto.params.DSAParameters;
import org.bouncycastle.crypto.params.DSAPrivateKeyParameters;
import org.bouncycastle.crypto.params.DSAPublicKeyParameters;
import org.bouncycastle.crypto.params.ParametersWithRandom;
/* loaded from: classes6.dex */
public class DSASigner implements DSA {
private final DSAKCalculator kCalculator;
private DSAKeyParameters key;
private SecureRandom random;
@Override // org.bouncycastle.crypto.DSA
public boolean verifySignature(byte[] bArr, BigInteger bigInteger, BigInteger bigInteger2) {
DSAParameters parameters = this.key.getParameters();
BigInteger q = parameters.getQ();
BigInteger calculateE = calculateE(q, bArr);
BigInteger valueOf = BigInteger.valueOf(0L);
if (valueOf.compareTo(bigInteger) >= 0 || q.compareTo(bigInteger) <= 0 || valueOf.compareTo(bigInteger2) >= 0 || q.compareTo(bigInteger2) <= 0) {
return false;
}
BigInteger modInverse = bigInteger2.modInverse(q);
BigInteger mod = calculateE.multiply(modInverse).mod(q);
BigInteger mod2 = bigInteger.multiply(modInverse).mod(q);
BigInteger p = parameters.getP();
return parameters.getG().modPow(mod, p).multiply(((DSAPublicKeyParameters) this.key).getY().modPow(mod2, p)).mod(p).mod(q).equals(bigInteger);
}
protected SecureRandom initSecureRandom(boolean z, SecureRandom secureRandom) {
if (z) {
return secureRandom == null ? new SecureRandom() : secureRandom;
}
return null;
}
@Override // org.bouncycastle.crypto.DSA
public void init(boolean z, CipherParameters cipherParameters) {
DSAKeyParameters dSAKeyParameters;
SecureRandom secureRandom;
if (!z) {
dSAKeyParameters = (DSAPublicKeyParameters) cipherParameters;
} else {
if (cipherParameters instanceof ParametersWithRandom) {
ParametersWithRandom parametersWithRandom = (ParametersWithRandom) cipherParameters;
this.key = (DSAPrivateKeyParameters) parametersWithRandom.getParameters();
secureRandom = parametersWithRandom.getRandom();
this.random = initSecureRandom((z || this.kCalculator.isDeterministic()) ? false : true, secureRandom);
}
dSAKeyParameters = (DSAPrivateKeyParameters) cipherParameters;
}
this.key = dSAKeyParameters;
secureRandom = null;
this.random = initSecureRandom((z || this.kCalculator.isDeterministic()) ? false : true, secureRandom);
}
@Override // org.bouncycastle.crypto.DSA
public BigInteger[] generateSignature(byte[] bArr) {
DSAParameters parameters = this.key.getParameters();
BigInteger q = parameters.getQ();
BigInteger calculateE = calculateE(q, bArr);
BigInteger x = ((DSAPrivateKeyParameters) this.key).getX();
if (this.kCalculator.isDeterministic()) {
this.kCalculator.init(q, x, bArr);
} else {
this.kCalculator.init(q, this.random);
}
BigInteger nextK = this.kCalculator.nextK();
BigInteger mod = parameters.getG().modPow(nextK, parameters.getP()).mod(q);
return new BigInteger[]{mod, nextK.modInverse(q).multiply(calculateE.add(x.multiply(mod))).mod(q)};
}
private BigInteger calculateE(BigInteger bigInteger, byte[] bArr) {
if (bigInteger.bitLength() >= (bArr.length << 3)) {
return new BigInteger(1, bArr);
}
int bitLength = bigInteger.bitLength() / 8;
byte[] bArr2 = new byte[bitLength];
System.arraycopy(bArr, 0, bArr2, 0, bitLength);
return new BigInteger(1, bArr2);
}
public DSASigner(DSAKCalculator dSAKCalculator) {
this.kCalculator = dSAKCalculator;
}
public DSASigner() {
this.kCalculator = new RandomDSAKCalculator();
}
}