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/*
* OpenSSL Block Cipher
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/eng_ossl.h>
#include <openssl/evp.h>
namespace Botan {
namespace {
/*
* EVP Block Cipher
*/
class EVP_BlockCipher : public BlockCipher
{
public:
void clear() throw();
std::string name() const { return cipher_name; }
BlockCipher* clone() const;
EVP_BlockCipher(const EVP_CIPHER*, const std::string&);
EVP_BlockCipher(const EVP_CIPHER*, const std::string&,
u32bit, u32bit, u32bit);
~EVP_BlockCipher();
private:
void enc(const byte[], byte[]) const;
void dec(const byte[], byte[]) const;
void key_schedule(const byte[], u32bit);
std::string cipher_name;
mutable EVP_CIPHER_CTX encrypt, decrypt;
};
/*
* EVP Block Cipher Constructor
*/
EVP_BlockCipher::EVP_BlockCipher(const EVP_CIPHER* algo,
const std::string& algo_name) :
BlockCipher(EVP_CIPHER_block_size(algo), EVP_CIPHER_key_length(algo)),
cipher_name(algo_name)
{
if(EVP_CIPHER_mode(algo) != EVP_CIPH_ECB_MODE)
throw Invalid_Argument("EVP_BlockCipher: Non-ECB EVP was passed in");
EVP_CIPHER_CTX_init(&encrypt);
EVP_CIPHER_CTX_init(&decrypt);
EVP_EncryptInit_ex(&encrypt, algo, 0, 0, 0);
EVP_DecryptInit_ex(&decrypt, algo, 0, 0, 0);
EVP_CIPHER_CTX_set_padding(&encrypt, 0);
EVP_CIPHER_CTX_set_padding(&decrypt, 0);
}
/*
* EVP Block Cipher Constructor
*/
EVP_BlockCipher::EVP_BlockCipher(const EVP_CIPHER* algo,
const std::string& algo_name,
u32bit key_min, u32bit key_max,
u32bit key_mod) :
BlockCipher(EVP_CIPHER_block_size(algo), key_min, key_max, key_mod),
cipher_name(algo_name)
{
if(EVP_CIPHER_mode(algo) != EVP_CIPH_ECB_MODE)
throw Invalid_Argument("EVP_BlockCipher: Non-ECB EVP was passed in");
EVP_CIPHER_CTX_init(&encrypt);
EVP_CIPHER_CTX_init(&decrypt);
EVP_EncryptInit_ex(&encrypt, algo, 0, 0, 0);
EVP_DecryptInit_ex(&decrypt, algo, 0, 0, 0);
EVP_CIPHER_CTX_set_padding(&encrypt, 0);
EVP_CIPHER_CTX_set_padding(&decrypt, 0);
}
/*
* EVP Block Cipher Destructor
*/
EVP_BlockCipher::~EVP_BlockCipher()
{
EVP_CIPHER_CTX_cleanup(&encrypt);
EVP_CIPHER_CTX_cleanup(&decrypt);
}
/*
* Encrypt a block
*/
void EVP_BlockCipher::enc(const byte in[], byte out[]) const
{
int out_len = 0;
EVP_EncryptUpdate(&encrypt, out, &out_len, in, BLOCK_SIZE);
}
/*
* Decrypt a block
*/
void EVP_BlockCipher::dec(const byte in[], byte out[]) const
{
int out_len = 0;
EVP_DecryptUpdate(&decrypt, out, &out_len, in, BLOCK_SIZE);
}
/*
* Set the key
*/
void EVP_BlockCipher::key_schedule(const byte key[], u32bit length)
{
SecureVector<byte> full_key(key, length);
if(cipher_name == "TripleDES" && length == 16)
full_key.append(key, 8);
else
if(EVP_CIPHER_CTX_set_key_length(&encrypt, length) == 0 ||
EVP_CIPHER_CTX_set_key_length(&decrypt, length) == 0)
throw Invalid_Argument("EVP_BlockCipher: Bad key length for " +
cipher_name);
if(cipher_name == "RC2")
{
EVP_CIPHER_CTX_ctrl(&encrypt, EVP_CTRL_SET_RC2_KEY_BITS, length*8, 0);
EVP_CIPHER_CTX_ctrl(&decrypt, EVP_CTRL_SET_RC2_KEY_BITS, length*8, 0);
}
EVP_EncryptInit_ex(&encrypt, 0, 0, full_key.begin(), 0);
EVP_DecryptInit_ex(&decrypt, 0, 0, full_key.begin(), 0);
}
/*
* Return a clone of this object
*/
BlockCipher* EVP_BlockCipher::clone() const
{
return new EVP_BlockCipher(EVP_CIPHER_CTX_cipher(&encrypt),
cipher_name, MINIMUM_KEYLENGTH,
MAXIMUM_KEYLENGTH, KEYLENGTH_MULTIPLE);
}
/*
* Clear memory of sensitive data
*/
void EVP_BlockCipher::clear() throw()
{
const EVP_CIPHER* algo = EVP_CIPHER_CTX_cipher(&encrypt);
EVP_CIPHER_CTX_cleanup(&encrypt);
EVP_CIPHER_CTX_cleanup(&decrypt);
EVP_CIPHER_CTX_init(&encrypt);
EVP_CIPHER_CTX_init(&decrypt);
EVP_EncryptInit_ex(&encrypt, algo, 0, 0, 0);
EVP_DecryptInit_ex(&decrypt, algo, 0, 0, 0);
EVP_CIPHER_CTX_set_padding(&encrypt, 0);
EVP_CIPHER_CTX_set_padding(&decrypt, 0);
}
}
/*
* Look for an algorithm with this name
*/
BlockCipher*
OpenSSL_Engine::find_block_cipher(const SCAN_Name& request,
Algorithm_Factory&) const
{
#define HANDLE_EVP_CIPHER(NAME, EVP) \
if(request.algo_name() == NAME && request.arg_count() == 0) \
return new EVP_BlockCipher(EVP, NAME);
#define HANDLE_EVP_CIPHER_KEYLEN(NAME, EVP, MIN, MAX, MOD) \
if(request.algo_name() == NAME && request.arg_count() == 0) \
return new EVP_BlockCipher(EVP, NAME, MIN, MAX, MOD);
#if 0
/*
Using OpenSSL's AES causes crashes inside EVP on x86-64 with OpenSSL 0.9.8g
cause is unknown
*/
HANDLE_EVP_CIPHER("AES-128", EVP_aes_128_ecb());
HANDLE_EVP_CIPHER("AES-192", EVP_aes_192_ecb());
HANDLE_EVP_CIPHER("AES-256", EVP_aes_256_ecb());
#endif
HANDLE_EVP_CIPHER("DES", EVP_des_ecb());
HANDLE_EVP_CIPHER_KEYLEN("TripleDES", EVP_des_ede3_ecb(), 16, 24, 8);
HANDLE_EVP_CIPHER_KEYLEN("Blowfish", EVP_bf_ecb(), 1, 56, 1);
HANDLE_EVP_CIPHER_KEYLEN("CAST-128", EVP_cast5_ecb(), 1, 16, 1);
HANDLE_EVP_CIPHER_KEYLEN("RC2", EVP_rc2_ecb(), 1, 32, 1);
#undef HANDLE_EVP_CIPHER
#undef HANDLE_EVP_CIPHER_KEYLEN
return 0;
}
}
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