libcryfs/implementations/encrypted/ciphers/AES256_CFB.cpp

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#include <cryptopp/cryptopp/modes.h>
#include "AES256_CFB.h"
using CryptoPP::CFB_Mode;
using CryptoPP::AES;
namespace blockstore {
namespace encrypted {
constexpr unsigned int AES256_CFB::IV_SIZE;
Data AES256_CFB::encrypt(const byte *plaintext, unsigned int plaintextSize, const EncryptionKey &encKey) {
FixedSizeData<IV_SIZE> iv = FixedSizeData<IV_SIZE>::CreateRandom();
auto encryption = CFB_Mode<AES>::Encryption(encKey.data(), encKey.BINARY_LENGTH, iv.data());
Data ciphertext(ciphertextSize(plaintextSize));
std::memcpy(ciphertext.data(), iv.data(), IV_SIZE);
encryption.ProcessData((byte*)ciphertext.data() + IV_SIZE, plaintext, plaintextSize);
return ciphertext;
}
boost::optional<Data> AES256_CFB::decrypt(const byte *ciphertext, unsigned int ciphertextSize, const EncryptionKey &encKey) {
const byte *ciphertextIV = ciphertext;
const byte *ciphertextData = ciphertext + IV_SIZE;
auto decryption = CFB_Mode<AES>::Decryption((byte*)encKey.data(), encKey.BINARY_LENGTH, ciphertextIV);
Data plaintext(plaintextSize(ciphertextSize));
decryption.ProcessData((byte*)plaintext.data(), ciphertextData, plaintext.size());
return std::move(plaintext);
}
}
}