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