Examples with Aead com.google.crypto.tink.Aead used on opensource projects

Example 46 with Aead

use of com.google.crypto.tink.Aead in project tink by google.

the class RsaKemHybridDecrypt method decrypt.

@Override
public byte[] decrypt(final byte[] ciphertext, final byte[] contextInfo) throws GeneralSecurityException {
    int modSizeInBytes = RsaKem.bigIntSizeInBytes(recipientPrivateKey.getModulus());
    if (ciphertext.length < modSizeInBytes) {
        throw new GeneralSecurityException(String.format("Ciphertext must be of at least size %d bytes, but got %d", modSizeInBytes, ciphertext.length));
    }
    // Decrypt the token to obtain the raw shared secret.
    ByteBuffer cipherBuffer = ByteBuffer.wrap(ciphertext);
    byte[] token = new byte[modSizeInBytes];
    cipherBuffer.get(token);
    Cipher rsaCipher = Cipher.getInstance("RSA/ECB/NoPadding");
    rsaCipher.init(Cipher.DECRYPT_MODE, recipientPrivateKey);
    byte[] sharedSecret = rsaCipher.doFinal(token);
    // KDF: derive a DEM key from the shared secret, salt, and contextInfo.
    byte[] demKey = Hkdf.computeHkdf(hkdfHmacAlgo, sharedSecret, hkdfSalt, contextInfo, aeadFactory.getKeySizeInBytes());
    // DEM: decrypt the payload.
    Aead aead = aeadFactory.createAead(demKey);
    byte[] demPayload = new byte[cipherBuffer.remaining()];
    cipherBuffer.get(demPayload);
    return aead.decrypt(demPayload, RsaKem.EMPTY_AAD);
}

Example 47 with Aead

use of com.google.crypto.tink.Aead in project tink by google.

the class RsaKemHybridEncrypt method encrypt.

@Override
public byte[] encrypt(final byte[] plaintext, final byte[] contextInfo) throws GeneralSecurityException {
    // KEM: generate a random shared secret whose bit length is equal to the modulus'.
    BigInteger mod = recipientPublicKey.getModulus();
    byte[] sharedSecret = RsaKem.generateSecret(mod);
    // KEM: encrypt the shared secret using the public key.
    Cipher rsaCipher = Cipher.getInstance("RSA/ECB/NoPadding");
    rsaCipher.init(Cipher.ENCRYPT_MODE, recipientPublicKey);
    byte[] token = rsaCipher.doFinal(sharedSecret);
    // KDF: derive a DEM key from the shared secret, salt, and contextInfo.
    byte[] demKey = Hkdf.computeHkdf(hkdfHmacAlgo, sharedSecret, hkdfSalt, contextInfo, aeadFactory.getKeySizeInBytes());
    Aead aead = aeadFactory.createAead(demKey);
    byte[] ciphertext = aead.encrypt(plaintext, RsaKem.EMPTY_AAD);
    return ByteBuffer.allocate(token.length + ciphertext.length).put(token).put(ciphertext).array();
}

Example 48 with Aead

use of com.google.crypto.tink.Aead in project tink by google.

the class AeadThreadSafetyTest method testAesCtrHmac.

@Test
public void testAesCtrHmac() throws Exception {
    byte[] key = Random.randBytes(16);
    byte[] macKey = Random.randBytes(32);
    int ivSize = 12;
    int macSize = 12;
    IndCpaCipher cipher = new AesCtrJceCipher(key, ivSize);
    SecretKeySpec keySpec = new SecretKeySpec(macKey, "HMAC");
    Mac mac = new PrfMac(new PrfHmacJce("HMACSHA256", keySpec), macSize);
    // TODO(b/148134669): Remove the following line.
    // There is a potential (but unlikely) race in java.security.Provider. Since AesCtrHmac
    // encryption creates a cipher for the first time in
    // http://google3/third_party/tink/java_src/src/main/java/com/google/crypto/tink/subtle/AesCtrJceCipher.java?l=128&rcl=272896379
    // if we do this multithreaded, there is a potential for a race in case we call encrypt
    // for the first time at the same time in multiple threads. To get around this, we first encrypt
    // an empty plaintext here.
    cipher.encrypt(new byte[0]);
    Aead aesCtrHmac = new EncryptThenAuthenticate(cipher, mac, macSize);
    testEncryptionDecryption(aesCtrHmac, 5, 128, 20);
}

Example 49 with Aead

use of com.google.crypto.tink.Aead in project tink by google.

the class AeadThreadSafetyTest method testChaChaPoly1305.

@Test
public void testChaChaPoly1305() throws Exception {
    byte[] key = Random.randBytes(32);
    Aead cipher = new ChaCha20Poly1305(key);
    testEncryptionDecryption(cipher, 5, 128, 20);
}

Example 50 with Aead

use of com.google.crypto.tink.Aead in project tink by google.

the class ChaCha20Poly1305Test method testDecryptThrowsGeneralSecurityExpWhenCiphertextIsTooShort.

@Test
public void testDecryptThrowsGeneralSecurityExpWhenCiphertextIsTooShort() throws GeneralSecurityException {
    Assume.assumeFalse(TinkFips.useOnlyFips());
    Aead cipher = createInstance(new byte[KEY_SIZE]);
    GeneralSecurityException e = assertThrows(GeneralSecurityException.class, () -> cipher.decrypt(new byte[27], new byte[1]));
    assertThat(e).hasMessageThat().containsMatch("ciphertext too short");
}