Esempio n. 1
0
            CryptoBuffer CommonCryptoCipher::DecryptBuffer(const CryptoBuffer& encryptedData)
            {
                if (m_failure)
                {
                    AWS_LOGSTREAM_FATAL(CC_LOG_TAG, "Cipher not properly initialized for decryption. Aborting");
                    return CryptoBuffer();
                }

                CheckInitDecryptor();
                size_t lengthWritten = encryptedData.GetLength() + (GetBlockSizeBytes() - 1);
                CryptoBuffer decryptedText(static_cast<size_t>(lengthWritten));

                CCStatus status = CCCryptorUpdate(m_cryptoHandle, encryptedData.GetUnderlyingData(), encryptedData.GetLength(),
                    decryptedText.GetUnderlyingData(), decryptedText.GetLength(), &lengthWritten);

                if (status != kCCSuccess)
                {
                    m_failure = true;
                    AWS_LOGSTREAM_ERROR(CC_LOG_TAG, "Decryption of buffer failed with status code: " << status);
                    return CryptoBuffer();
                }

                if (lengthWritten < decryptedText.GetLength())
                {
                    return CryptoBuffer(decryptedText.GetUnderlyingData(), static_cast<size_t>(lengthWritten));
                }

                return decryptedText;
            }
Esempio n. 2
0
            void SymmetricCipher::Validate()
            {
                assert(m_key.GetLength() >= SYMMETRIC_KEY_LENGTH);
                assert(m_initializationVector.GetLength() == 0 || m_initializationVector.GetLength() >= MIN_IV_LENGTH);

                if(m_key.GetLength() < SYMMETRIC_KEY_LENGTH || 
                    (m_initializationVector.GetLength() > 0 && m_initializationVector.GetLength() < MIN_IV_LENGTH))
                {
                    m_failure = true;
                    AWS_LOGSTREAM_FATAL(LOG_TAG, "Invalid state for symmetric cipher, key length is " << m_key.GetLength() <<
                                            " iv length is " << m_initializationVector.GetLength());
                }
            }
Esempio n. 3
0
            CryptoBuffer GenerateXRandomBytes(size_t lengthBytes, bool ctrMode)
            {
                std::shared_ptr<SecureRandomBytes> rng = CreateSecureRandomBytesImplementation();

                CryptoBuffer bytes(lengthBytes);
                size_t lengthToGenerate = ctrMode ? (3 * bytes.GetLength())  / 4 : bytes.GetLength();
                
                rng->GetBytes(bytes.GetUnderlyingData(), lengthToGenerate);

                if(!*rng)
                {
                    AWS_LOGSTREAM_FATAL(LOG_TAG, "Random Number generation failed. Abort all crypto operations.");
                    assert(false);
                    abort();                    
                }

                return bytes;
            }
Esempio n. 4
0
            CryptoBuffer CommonCryptoCipher::FinalizeDecryption()
            {
                if (m_failure)
                {
                    AWS_LOGSTREAM_FATAL(CC_LOG_TAG,
                                        "Cipher not properly initialized for decryption finalization. Aborting");
                    return CryptoBuffer();
                }

                CryptoBuffer finalBlock(GetBlockSizeBytes());
                size_t writtenSize = static_cast<int>(finalBlock.GetLength());
                CCStatus status = CCCryptorFinal(m_cryptoHandle, finalBlock.GetUnderlyingData(), finalBlock.GetLength(), &writtenSize);
                if (status != kCCSuccess)
                {
                    m_failure = true;
                    AWS_LOGSTREAM_ERROR(CC_LOG_TAG, "Decryption of buffer failed with status code: " << status);
                    return CryptoBuffer();
                }
                return CryptoBuffer(finalBlock.GetUnderlyingData(), writtenSize);
            }