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/*
* TLS Cipher Suite
* (C) 2004-2010,2012,2013 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/tls_ciphersuite.h>
#include <botan/libstate.h>
#include <botan/parsing.h>
#include <sstream>
#include <stdexcept>
namespace Botan {
namespace TLS {
namespace {
/*
* This way all work happens at the constuctor call, and we can
* rely on that happening only once in C++11.
*/
std::vector<Ciphersuite> gather_known_ciphersuites()
{
std::vector<Ciphersuite> ciphersuites;
for(size_t i = 0; i <= 0xFFFF; ++i)
{
Ciphersuite suite = Ciphersuite::by_id(i);
if(suite.valid())
ciphersuites.push_back(suite);
}
return ciphersuites;
}
}
const std::vector<Ciphersuite>& Ciphersuite::all_known_ciphersuites()
{
static std::vector<Ciphersuite> all_ciphersuites(gather_known_ciphersuites());
return all_ciphersuites;
}
Ciphersuite Ciphersuite::by_name(const std::string& name)
{
for(auto suite : all_known_ciphersuites())
{
if(suite.to_string() == name)
return suite;
}
return Ciphersuite(); // some unknown ciphersuite
}
bool Ciphersuite::is_scsv(u16bit suite)
{
// TODO: derive from IANA file in script
return (suite == 0x00FF || suite == 0x5600);
}
Ciphersuite::Ciphersuite(u16bit ciphersuite_code,
const char* sig_algo,
const char* kex_algo,
const char* cipher_algo,
size_t cipher_keylen,
size_t nonce_bytes_from_handshake,
size_t nonce_bytes_from_record,
const char* mac_algo,
size_t mac_keylen,
const char* prf_algo) :
m_ciphersuite_code(ciphersuite_code),
m_sig_algo(sig_algo),
m_kex_algo(kex_algo),
m_prf_algo(prf_algo),
m_cipher_algo(cipher_algo),
m_cipher_keylen(cipher_keylen),
m_nonce_bytes_from_handshake(nonce_bytes_from_handshake),
m_nonce_bytes_from_record(nonce_bytes_from_record),
m_mac_algo(mac_algo),
m_mac_keylen(mac_keylen)
{
}
bool Ciphersuite::psk_ciphersuite() const
{
return (kex_algo() == "PSK" ||
kex_algo() == "DHE_PSK" ||
kex_algo() == "ECDHE_PSK");
}
bool Ciphersuite::ecc_ciphersuite() const
{
return (sig_algo() == "ECDSA" || kex_algo() == "ECDH" || kex_algo() == "ECDHE_PSK");
}
bool Ciphersuite::valid() const
{
if(!m_cipher_keylen) // uninitialized object
return false;
Algorithm_Factory& af = global_state().algorithm_factory();
if(!af.prototype_hash_function(prf_algo()))
return false;
if(mac_algo() == "AEAD")
{
if(cipher_algo() == "ChaCha20Poly1305")
{
#if !defined(BOTAN_HAS_AEAD_CHACHA20_POLY1305)
return false;
#endif
}
else
{
auto cipher_and_mode = split_on(cipher_algo(), '/');
BOTAN_ASSERT(cipher_and_mode.size() == 2, "Expected format for AEAD algo");
if(!af.prototype_block_cipher(cipher_and_mode[0]))
return false;
const auto mode = cipher_and_mode[1];
#if !defined(BOTAN_HAS_AEAD_CCM)
if(mode == "CCM" || mode == "CCM-8")
return false;
#endif
#if !defined(BOTAN_HAS_AEAD_GCM)
if(mode == "GCM")
return false;
#endif
#if !defined(BOTAN_HAS_AEAD_OCB)
if(mode == "OCB(12)" || mode == "OCB")
return false;
#endif
}
}
else
{
if(!af.prototype_block_cipher(cipher_algo()) &&
!af.prototype_stream_cipher(cipher_algo()))
return false;
if(!af.prototype_hash_function(mac_algo()))
return false;
}
if(kex_algo() == "SRP_SHA")
{
#if !defined(BOTAN_HAS_SRP6)
return false;
#endif
}
else if(kex_algo() == "ECDH" || kex_algo() == "ECDHE_PSK")
{
#if !defined(BOTAN_HAS_ECDH)
return false;
#endif
}
else if(kex_algo() == "DH" || kex_algo() == "DHE_PSK")
{
#if !defined(BOTAN_HAS_DIFFIE_HELLMAN)
return false;
#endif
}
if(sig_algo() == "DSA")
{
#if !defined(BOTAN_HAS_DSA)
return false;
#endif
}
else if(sig_algo() == "ECDSA")
{
#if !defined(BOTAN_HAS_ECDSA)
return false;
#endif
}
else if(sig_algo() == "RSA")
{
#if !defined(BOTAN_HAS_RSA)
return false;
#endif
}
return true;
}
std::string Ciphersuite::to_string() const
{
if(m_cipher_keylen == 0)
throw std::runtime_error("Ciphersuite::to_string - no value set");
std::ostringstream out;
out << "TLS_";
if(kex_algo() != "RSA")
{
if(kex_algo() == "DH")
out << "DHE";
else if(kex_algo() == "ECDH")
out << "ECDHE";
else
out << kex_algo();
out << '_';
}
if(sig_algo() == "DSA")
out << "DSS_";
else if(sig_algo() != "")
out << sig_algo() << '_';
out << "WITH_";
if(cipher_algo() == "RC4")
{
out << "RC4_128_";
}
else if(cipher_algo() == "ChaCha20Poly1305")
{
out << "CHACHA20_POLY1305_";
}
else
{
if(cipher_algo() == "3DES")
out << "3DES_EDE";
else if(cipher_algo().find("Camellia") == 0)
out << "CAMELLIA_" << std::to_string(8*cipher_keylen());
else
{
if(cipher_algo().find("OCB(12)") != std::string::npos)
out << replace_chars(cipher_algo().substr(0, cipher_algo().size() - 4),
{'-', '/'}, '_');
else
out << replace_chars(cipher_algo(), {'-', '/'}, '_');
}
if(cipher_algo().find("/") != std::string::npos)
out << "_"; // some explicit mode already included
else
out << "_CBC_";
}
if(mac_algo() == "SHA-1")
out << "SHA";
else if(mac_algo() == "AEAD")
out << erase_chars(prf_algo(), {'-'});
else
out << erase_chars(mac_algo(), {'-'});
return out.str();
}
}
}
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