what-the-bank/sources/org/bouncycastle/crypto/generators/Poly1305KeyGenerator.java

55 lines
1.9 KiB
Java

package org.bouncycastle.crypto.generators;
import org.bouncycastle.crypto.CipherKeyGenerator;
import org.bouncycastle.crypto.KeyGenerationParameters;
/* loaded from: classes6.dex */
public class Poly1305KeyGenerator extends CipherKeyGenerator {
private static final byte R_MASK_HIGH_4 = 15;
private static final byte R_MASK_LOW_2 = -4;
@Override // org.bouncycastle.crypto.CipherKeyGenerator
public void init(KeyGenerationParameters keyGenerationParameters) {
super.init(new KeyGenerationParameters(keyGenerationParameters.getRandom(), 256));
}
@Override // org.bouncycastle.crypto.CipherKeyGenerator
public byte[] generateKey() {
byte[] generateKey = super.generateKey();
clamp(generateKey);
return generateKey;
}
public static void clamp(byte[] bArr) {
if (bArr.length != 32) {
throw new IllegalArgumentException("Poly1305 key must be 256 bits.");
}
bArr[3] = (byte) (bArr[3] & 15);
bArr[7] = (byte) (bArr[7] & 15);
bArr[11] = (byte) (bArr[11] & 15);
bArr[15] = (byte) (bArr[15] & 15);
bArr[4] = (byte) (bArr[4] & R_MASK_LOW_2);
bArr[8] = (byte) (bArr[8] & R_MASK_LOW_2);
bArr[12] = (byte) (bArr[12] & R_MASK_LOW_2);
}
private static void checkMask(byte b, byte b2) {
if ((b & (~b2)) != 0) {
throw new IllegalArgumentException("Invalid format for r portion of Poly1305 key.");
}
}
public static void checkKey(byte[] bArr) {
if (bArr.length != 32) {
throw new IllegalArgumentException("Poly1305 key must be 256 bits.");
}
checkMask(bArr[3], (byte) 15);
checkMask(bArr[7], (byte) 15);
checkMask(bArr[11], (byte) 15);
checkMask(bArr[15], (byte) 15);
checkMask(bArr[4], R_MASK_LOW_2);
checkMask(bArr[8], R_MASK_LOW_2);
checkMask(bArr[12], R_MASK_LOW_2);
}
}