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;
}
CryptoBuffer AES_KeyWrap_Cipher_CommonCrypto::DecryptBuffer(const CryptoBuffer& encryptedData)
{
CheckInitDecryptor();
m_workingKeyBuffer = CryptoBuffer({&m_workingKeyBuffer, (CryptoBuffer*)&encryptedData});
return CryptoBuffer();
}
CryptoBuffer AES_KeyWrap_Cipher_CommonCrypto::FinalizeDecryption()
{
CheckInitDecryptor();
size_t outputBufferLength = m_workingKeyBuffer.GetLength() - GetBlockSizeBytes();
CryptoBuffer outputBuffer(outputBufferLength);
CCCryptorStatus status = CCSymmetricKeyUnwrap(kCCWRAPAES, CCrfc3394_iv, CCrfc3394_ivLen, m_key.GetUnderlyingData(), m_key.GetLength(),
m_workingKeyBuffer.GetUnderlyingData(), m_workingKeyBuffer.GetLength(), outputBuffer.GetUnderlyingData(), &outputBufferLength);
if(status != kCCSuccess)
{
m_failure = true;
AWS_LOGSTREAM_ERROR(AES_KEY_WRAP_LOG_TAG, "Key unwrap failed with status code " << status);
return CryptoBuffer();
}
return outputBuffer;
}
