Hello, I'm having some AES encryption/decryption problems. The issue comes
into play with certian IV's.
My IV's are completely randomized for security, however, I'm not sure If I'm
loading them in/out correctly.
I get the: StreamTransformationFilter: ciphertext length is not a multiple
of block size error.
CODE:
int xxz568::AESEncrypt(std::string key, std::string input, std::string
&output) {
byte keyB[32], ivB[AES::BLOCKSIZE];
std::string hashKey = sha1(key).substr(0, 32);
memcpy(keyB, hashKey.c_str(), 32);
//
memcpy(ivB, generateRandLen(), 16);
//
std::string hold, final, hexVec, decVec;
HexEncode((const char *)ivB, hexVec);
cout << "IV: " << ivB << " | " << hexVec << endl;
output = hexVec.substr(0, 32);
//convert output back to binary for usage as the initVector
HexDecode(output, decVec);
//store dec Vec in the iv slot
memcpy(ivB, decVec.c_str(), 16);
StringSink* sink = new StringSink(hold);
CBC_Mode<AES>::Encryption aes(keyB, sizeof(keyB), ivB);
StreamTransformationFilter* aes_enc = new StreamTransformationFilter(aes,
sink);
StringSource cipher(input, true, aes_enc);
//convert to a hash
HexEncode(hold, final);
output += final;
//
return 1;
}
int xxz568::AESDecrypt(std::string key, std::string input, std::string
&output) {
std::string bin, store2, init, test;
HexDecode(input, bin);
cout << "DEC: " << bin << endl;
try{
byte keyB[32], iv[AES::BLOCKSIZE];
std::string hashKey = sha1(key).substr(0, 32);
memcpy(keyB, hashKey.c_str(), 32);
//obtain IV
init.assign(bin.substr(0, 16));
memcpy(iv, init.c_str(), 16);
HexEncode(init, test);
store2.assign(bin.substr(16, bin.length()));
cout << "IV: " << init << " | " << test << endl;
//
StringSink* sink = new StringSink(output);
CBC_Mode<AES>::Decryption aes(keyB, sizeof(keyB), iv);
StreamTransformationFilter* aes_enc = new
StreamTransformationFilter(aes, sink);
StringSource cipher(store2, true, aes_enc);
}
catch(CryptoPP::Exception e) {
cout << e.GetWhat() << endl;
output = "Decrypt Error:";
output.append(e.GetWhat());
}
return 1;
}
byte * xxz568::generateRandLen() {
AutoSeededRandomPool rng;
byte randLen[16];
rng.GenerateBlock(randLen, 16);
//
return randLen;
}
int xxz568::HexEncode(std::string input, std::string &output) {
CryptoPP::StringSource foo(input, true,
new CryptoPP::HexEncoder(
new CryptoPP::StringSink(output), false));
return 1;
}
int xxz568::HexDecode(std::string input, std::string &output) {
CryptoPP::StringSource foo(input, true,
new CryptoPP::HexDecoder(
new CryptoPP::StringSink(output)));
return 1;
}
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