109 lines
3.8 KiB
Java
109 lines
3.8 KiB
Java
package org.bouncycastle.crypto.generators;
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import org.bouncycastle.crypto.DataLengthException;
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import org.bouncycastle.crypto.DerivationFunction;
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import org.bouncycastle.crypto.DerivationParameters;
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import org.bouncycastle.crypto.Digest;
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import org.bouncycastle.crypto.macs.HMac;
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import org.bouncycastle.crypto.params.HKDFParameters;
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import org.bouncycastle.crypto.params.KeyParameter;
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/* loaded from: classes6.dex */
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public class HKDFBytesGenerator implements DerivationFunction {
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private byte[] currentT;
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private int generatedBytes;
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private HMac hMacHash;
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private int hashLen;
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private byte[] info;
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@Override // org.bouncycastle.crypto.DerivationFunction
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public void init(DerivationParameters derivationParameters) {
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HMac hMac;
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KeyParameter extract;
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if (!(derivationParameters instanceof HKDFParameters)) {
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throw new IllegalArgumentException("HKDF parameters required for HKDFBytesGenerator");
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}
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HKDFParameters hKDFParameters = (HKDFParameters) derivationParameters;
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if (hKDFParameters.skipExtract()) {
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hMac = this.hMacHash;
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extract = new KeyParameter(hKDFParameters.getIKM());
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} else {
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hMac = this.hMacHash;
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extract = extract(hKDFParameters.getSalt(), hKDFParameters.getIKM());
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}
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hMac.init(extract);
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this.info = hKDFParameters.getInfo();
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this.generatedBytes = 0;
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this.currentT = new byte[this.hashLen];
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}
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public Digest getDigest() {
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return this.hMacHash.getUnderlyingDigest();
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}
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@Override // org.bouncycastle.crypto.DerivationFunction
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public int generateBytes(byte[] bArr, int i, int i2) throws DataLengthException, IllegalArgumentException {
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int i3 = this.generatedBytes;
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int i4 = this.hashLen;
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if (i3 + i2 > i4 * 255) {
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throw new DataLengthException("HKDF may only be used for 255 * HashLen bytes of output");
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}
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if (i3 % i4 == 0) {
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expandNext();
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}
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int i5 = this.generatedBytes;
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int i6 = this.hashLen;
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int i7 = i5 % i6;
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int min = Math.min(i6 - i7, i2);
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System.arraycopy(this.currentT, i7, bArr, i, min);
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this.generatedBytes += min;
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int i8 = i2 - min;
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while (true) {
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i += min;
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if (i8 <= 0) {
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return i2;
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}
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expandNext();
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min = Math.min(this.hashLen, i8);
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System.arraycopy(this.currentT, 0, bArr, i, min);
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this.generatedBytes += min;
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i8 -= min;
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}
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}
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private KeyParameter extract(byte[] bArr, byte[] bArr2) {
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this.hMacHash.init(new KeyParameter(bArr2));
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if (bArr == null) {
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this.hMacHash.init(new KeyParameter(new byte[this.hashLen]));
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} else {
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this.hMacHash.init(new KeyParameter(bArr));
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}
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this.hMacHash.update(bArr2, 0, bArr2.length);
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byte[] bArr3 = new byte[this.hashLen];
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this.hMacHash.doFinal(bArr3, 0);
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return new KeyParameter(bArr3);
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}
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private void expandNext() throws DataLengthException {
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int i = this.generatedBytes;
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int i2 = this.hashLen;
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int i3 = (i / i2) + 1;
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if (i3 >= 256) {
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throw new DataLengthException("HKDF cannot generate more than 255 blocks of HashLen size");
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}
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if (i != 0) {
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this.hMacHash.update(this.currentT, 0, i2);
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}
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HMac hMac = this.hMacHash;
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byte[] bArr = this.info;
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hMac.update(bArr, 0, bArr.length);
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this.hMacHash.update((byte) i3);
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this.hMacHash.doFinal(this.currentT, 0);
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}
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public HKDFBytesGenerator(Digest digest) {
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this.hMacHash = new HMac(digest);
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this.hashLen = digest.getDigestSize();
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}
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}
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