74 lines
3.2 KiB
Java
74 lines
3.2 KiB
Java
package org.bouncycastle.crypto.kems;
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import java.math.BigInteger;
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import java.security.SecureRandom;
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import org.bouncycastle.crypto.CipherParameters;
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import org.bouncycastle.crypto.DerivationFunction;
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import org.bouncycastle.crypto.KeyEncapsulation;
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import org.bouncycastle.crypto.params.KDFParameters;
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import org.bouncycastle.crypto.params.KeyParameter;
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import org.bouncycastle.crypto.params.RSAKeyParameters;
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import org.bouncycastle.util.BigIntegers;
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/* loaded from: classes6.dex */
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public class RSAKeyEncapsulation implements KeyEncapsulation {
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private DerivationFunction kdf;
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private RSAKeyParameters key;
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private SecureRandom rnd;
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private static final BigInteger ZERO = BigInteger.valueOf(0);
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private static final BigInteger ONE = BigInteger.valueOf(1);
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@Override // org.bouncycastle.crypto.KeyEncapsulation
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public void init(CipherParameters cipherParameters) throws IllegalArgumentException {
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if (!(cipherParameters instanceof RSAKeyParameters)) {
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throw new IllegalArgumentException("RSA key required");
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}
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this.key = (RSAKeyParameters) cipherParameters;
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}
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protected KeyParameter generateKey(BigInteger bigInteger, BigInteger bigInteger2, int i) {
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this.kdf.init(new KDFParameters(BigIntegers.asUnsignedByteArray((bigInteger.bitLength() + 7) / 8, bigInteger2), null));
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byte[] bArr = new byte[i];
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this.kdf.generateBytes(bArr, 0, i);
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return new KeyParameter(bArr);
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}
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@Override // org.bouncycastle.crypto.KeyEncapsulation
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public CipherParameters encrypt(byte[] bArr, int i, int i2) throws IllegalArgumentException {
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if (this.key.isPrivate()) {
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throw new IllegalArgumentException("Public key required for encryption");
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}
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BigInteger modulus = this.key.getModulus();
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BigInteger exponent = this.key.getExponent();
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BigInteger createRandomInRange = BigIntegers.createRandomInRange(ZERO, modulus.subtract(ONE), this.rnd);
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byte[] asUnsignedByteArray = BigIntegers.asUnsignedByteArray((modulus.bitLength() + 7) / 8, createRandomInRange.modPow(exponent, modulus));
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System.arraycopy(asUnsignedByteArray, 0, bArr, i, asUnsignedByteArray.length);
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return generateKey(modulus, createRandomInRange, i2);
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}
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public CipherParameters encrypt(byte[] bArr, int i) {
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return encrypt(bArr, 0, i);
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}
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@Override // org.bouncycastle.crypto.KeyEncapsulation
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public CipherParameters decrypt(byte[] bArr, int i, int i2, int i3) throws IllegalArgumentException {
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if (!this.key.isPrivate()) {
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throw new IllegalArgumentException("Private key required for decryption");
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}
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BigInteger modulus = this.key.getModulus();
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BigInteger exponent = this.key.getExponent();
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byte[] bArr2 = new byte[i2];
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System.arraycopy(bArr, i, bArr2, 0, i2);
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return generateKey(modulus, new BigInteger(1, bArr2).modPow(exponent, modulus), i3);
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}
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public CipherParameters decrypt(byte[] bArr, int i) {
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return decrypt(bArr, 0, bArr.length, i);
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}
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public RSAKeyEncapsulation(DerivationFunction derivationFunction, SecureRandom secureRandom) {
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this.kdf = derivationFunction;
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this.rnd = secureRandom;
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}
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}
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