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

package org.bouncycastle.crypto.generators;

import org.bouncycastle.crypto.DataLengthException;
import org.bouncycastle.crypto.DerivationFunction;
import org.bouncycastle.crypto.DerivationParameters;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.crypto.params.HKDFParameters;
import org.bouncycastle.crypto.params.KeyParameter;

/* loaded from: classes6.dex */
public class HKDFBytesGenerator implements DerivationFunction {
    private byte[] currentT;
    private int generatedBytes;
    private HMac hMacHash;
    private int hashLen;
    private byte[] info;

    @Override // org.bouncycastle.crypto.DerivationFunction
    public void init(DerivationParameters derivationParameters) {
        HMac hMac;
        KeyParameter extract;
        if (!(derivationParameters instanceof HKDFParameters)) {
            throw new IllegalArgumentException("HKDF parameters required for HKDFBytesGenerator");
        }
        HKDFParameters hKDFParameters = (HKDFParameters) derivationParameters;
        if (hKDFParameters.skipExtract()) {
            hMac = this.hMacHash;
            extract = new KeyParameter(hKDFParameters.getIKM());
        } else {
            hMac = this.hMacHash;
            extract = extract(hKDFParameters.getSalt(), hKDFParameters.getIKM());
        }
        hMac.init(extract);
        this.info = hKDFParameters.getInfo();
        this.generatedBytes = 0;
        this.currentT = new byte[this.hashLen];
    }

    public Digest getDigest() {
        return this.hMacHash.getUnderlyingDigest();
    }

    @Override // org.bouncycastle.crypto.DerivationFunction
    public int generateBytes(byte[] bArr, int i, int i2) throws DataLengthException, IllegalArgumentException {
        int i3 = this.generatedBytes;
        int i4 = this.hashLen;
        if (i3 + i2 > i4 * 255) {
            throw new DataLengthException("HKDF may only be used for 255 * HashLen bytes of output");
        }
        if (i3 % i4 == 0) {
            expandNext();
        }
        int i5 = this.generatedBytes;
        int i6 = this.hashLen;
        int i7 = i5 % i6;
        int min = Math.min(i6 - i7, i2);
        System.arraycopy(this.currentT, i7, bArr, i, min);
        this.generatedBytes += min;
        int i8 = i2 - min;
        while (true) {
            i += min;
            if (i8 <= 0) {
                return i2;
            }
            expandNext();
            min = Math.min(this.hashLen, i8);
            System.arraycopy(this.currentT, 0, bArr, i, min);
            this.generatedBytes += min;
            i8 -= min;
        }
    }

    private KeyParameter extract(byte[] bArr, byte[] bArr2) {
        this.hMacHash.init(new KeyParameter(bArr2));
        if (bArr == null) {
            this.hMacHash.init(new KeyParameter(new byte[this.hashLen]));
        } else {
            this.hMacHash.init(new KeyParameter(bArr));
        }
        this.hMacHash.update(bArr2, 0, bArr2.length);
        byte[] bArr3 = new byte[this.hashLen];
        this.hMacHash.doFinal(bArr3, 0);
        return new KeyParameter(bArr3);
    }

    private void expandNext() throws DataLengthException {
        int i = this.generatedBytes;
        int i2 = this.hashLen;
        int i3 = (i / i2) + 1;
        if (i3 >= 256) {
            throw new DataLengthException("HKDF cannot generate more than 255 blocks of HashLen size");
        }
        if (i != 0) {
            this.hMacHash.update(this.currentT, 0, i2);
        }
        HMac hMac = this.hMacHash;
        byte[] bArr = this.info;
        hMac.update(bArr, 0, bArr.length);
        this.hMacHash.update((byte) i3);
        this.hMacHash.doFinal(this.currentT, 0);
    }

    public HKDFBytesGenerator(Digest digest) {
        this.hMacHash = new HMac(digest);
        this.hashLen = digest.getDigestSize();
    }
}