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/*
* Stream Ciphers
* (C) 2015,2016 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/stream_cipher.h>
#include <botan/scan_name.h>
#include <botan/exceptn.h>
#if defined(BOTAN_HAS_CHACHA)
#include <botan/chacha.h>
#endif
#if defined(BOTAN_HAS_SALSA20)
#include <botan/salsa20.h>
#endif
#if defined(BOTAN_HAS_SHAKE_CIPHER)
#include <botan/shake_cipher.h>
#endif
#if defined(BOTAN_HAS_CTR_BE)
#include <botan/ctr.h>
#endif
#if defined(BOTAN_HAS_OFB)
#include <botan/ofb.h>
#endif
#if defined(BOTAN_HAS_RC4)
#include <botan/rc4.h>
#endif
#if defined(BOTAN_HAS_OPENSSL)
#include <botan/internal/openssl.h>
#endif
namespace Botan {
std::unique_ptr<StreamCipher> StreamCipher::create(const std::string& algo_spec,
const std::string& provider)
{
const SCAN_Name req(algo_spec);
#if defined(BOTAN_HAS_CTR_BE)
if((req.algo_name() == "CTR-BE" || req.algo_name() == "CTR") && req.arg_count_between(1,2))
{
if(provider.empty() || provider == "base")
{
auto cipher = BlockCipher::create(req.arg(0));
if(cipher)
{
size_t ctr_size = req.arg_as_integer(1, cipher->block_size());
return std::unique_ptr<StreamCipher>(new CTR_BE(cipher.release(), ctr_size));
}
}
}
#endif
#if defined(BOTAN_HAS_CHACHA)
if(req.algo_name() == "ChaCha")
{
if(provider.empty() || provider == "base")
return std::unique_ptr<StreamCipher>(new ChaCha(req.arg_as_integer(0, 20)));
}
if(req.algo_name() == "ChaCha20")
{
if(provider.empty() || provider == "base")
return std::unique_ptr<StreamCipher>(new ChaCha(20));
}
#endif
#if defined(BOTAN_HAS_SALSA20)
if(req.algo_name() == "Salsa20")
{
if(provider.empty() || provider == "base")
return std::unique_ptr<StreamCipher>(new Salsa20);
}
#endif
#if defined(BOTAN_HAS_SHAKE_CIPHER)
if(req.algo_name() == "SHAKE-128" || req.algo_name() == "SHAKE-128-XOF")
{
if(provider.empty() || provider == "base")
return std::unique_ptr<StreamCipher>(new SHAKE_128_Cipher);
}
#endif
#if defined(BOTAN_HAS_OFB)
if(req.algo_name() == "OFB" && req.arg_count() == 1)
{
if(provider.empty() || provider == "base")
{
if(auto c = BlockCipher::create(req.arg(0)))
return std::unique_ptr<StreamCipher>(new OFB(c.release()));
}
}
#endif
#if defined(BOTAN_HAS_RC4)
if(req.algo_name() == "RC4" ||
req.algo_name() == "ARC4" ||
req.algo_name() == "MARK-4")
{
const size_t skip = (req.algo_name() == "MARK-4") ? 256 : req.arg_as_integer(0, 0);
#if defined(BOTAN_HAS_OPENSSL)
if(provider.empty() || provider == "openssl")
{
return std::unique_ptr<StreamCipher>(make_openssl_rc4(skip));
}
#endif
if(provider.empty() || provider == "base")
{
return std::unique_ptr<StreamCipher>(new RC4(skip));
}
}
#endif
BOTAN_UNUSED(req);
BOTAN_UNUSED(provider);
return nullptr;
}
//static
std::unique_ptr<StreamCipher>
StreamCipher::create_or_throw(const std::string& algo,
const std::string& provider)
{
if(auto sc = StreamCipher::create(algo, provider))
{
return sc;
}
throw Lookup_Error("Stream cipher", algo, provider);
}
std::vector<std::string> StreamCipher::providers(const std::string& algo_spec)
{
return probe_providers_of<StreamCipher>(algo_spec, {"base", "openssl"});
}
}