diff options
Diffstat (limited to 'src/tls/tls_policy.cpp')
| -rw-r--r-- | src/tls/tls_policy.cpp | 232 |
1 files changed, 151 insertions, 81 deletions
diff --git a/src/tls/tls_policy.cpp b/src/tls/tls_policy.cpp index b510c3d4b..bc0cd53f5 100644 --- a/src/tls/tls_policy.cpp +++ b/src/tls/tls_policy.cpp @@ -1,95 +1,166 @@ /* * Policies for TLS -* (C) 2004-2010 Jack Lloyd +* (C) 2004-2010,2012 Jack Lloyd * * Released under the terms of the Botan license */ #include <botan/tls_policy.h> +#include <botan/tls_suites.h> #include <botan/tls_exceptn.h> +#include <botan/internal/stl_util.h> namespace Botan { -/* -* Return allowed ciphersuites -*/ -std::vector<u16bit> TLS_Policy::ciphersuites(bool have_srp) const +std::vector<std::string> TLS_Policy::allowed_ciphers() const { - return suite_list(allow_static_rsa(), allow_edh_rsa(), allow_edh_dsa(), - allow_srp() && have_srp); + std::vector<std::string> allowed; + allowed.push_back("AES-256"); + allowed.push_back("AES-128"); + allowed.push_back("TripleDES"); + allowed.push_back("ARC4"); + // Note that SEED is not included by default + return allowed; } -/* -* Return allowed ciphersuites -*/ -std::vector<u16bit> TLS_Policy::suite_list(bool use_rsa, - bool use_edh_rsa, - bool use_edh_dsa, - bool use_srp) const +std::vector<std::string> TLS_Policy::allowed_hashes() const { - std::vector<u16bit> suites; + std::vector<std::string> allowed; + allowed.push_back("SHA-256"); + allowed.push_back("SHA-1"); + // Note that MD5 is not included by default + return allowed; + } - if(use_srp) - { - if(use_edh_rsa) - { - suites.push_back(TLS_SRP_SHA_DSS_WITH_AES_256_SHA); - suites.push_back(TLS_SRP_SHA_DSS_WITH_AES_128_SHA); - suites.push_back(TLS_SRP_SHA_DSS_WITH_3DES_EDE_SHA); - } +std::vector<std::string> TLS_Policy::allowed_key_exchange_methods() const + { + std::vector<std::string> allowed; + //allowed.push_back("ECDH"); + //allowed.push_back("SRP"); + allowed.push_back("DH"); + allowed.push_back(""); // means RSA via server cert + return allowed; + } - if(use_edh_dsa) +std::vector<std::string> TLS_Policy::allowed_signature_methods() const + { + std::vector<std::string> allowed; + //allowed.push_back("ECDSA"); + allowed.push_back("RSA"); + allowed.push_back("DSA"); + return allowed; + } + +namespace { + +class Ciphersuite_Preference_Ordering + { + public: + Ciphersuite_Preference_Ordering(const std::vector<std::string>& ciphers, + const std::vector<std::string>& hashes, + const std::vector<std::string>& kex, + const std::vector<std::string>& sigs) : + m_ciphers(ciphers), m_hashes(hashes), m_kex(kex), m_sigs(sigs) {} + + bool operator()(const TLS_Ciphersuite& a, const TLS_Ciphersuite& b) const { - suites.push_back(TLS_SRP_SHA_RSA_WITH_AES_256_SHA); - suites.push_back(TLS_SRP_SHA_RSA_WITH_AES_128_SHA); - suites.push_back(TLS_SRP_SHA_RSA_WITH_3DES_EDE_SHA); + if(a.kex_algo() != b.kex_algo()) + { + for(size_t i = 0; i != m_kex.size(); ++i) + { + if(a.kex_algo() == m_kex[i]) + return true; + if(b.kex_algo() == m_kex[i]) + return false; + } + } + + if(a.cipher_algo() != b.cipher_algo()) + { + for(size_t i = 0; i != m_ciphers.size(); ++i) + { + if(a.cipher_algo() == m_ciphers[i]) + return true; + if(b.cipher_algo() == m_ciphers[i]) + return false; + } + } + + if(a.sig_algo() != b.sig_algo()) + { + for(size_t i = 0; i != m_sigs.size(); ++i) + { + if(a.sig_algo() == m_sigs[i]) + return true; + if(b.sig_algo() == m_sigs[i]) + return false; + } + } + + if(a.mac_algo() != b.mac_algo()) + { + for(size_t i = 0; i != m_hashes.size(); ++i) + { + if(a.mac_algo() == m_hashes[i]) + return true; + if(b.mac_algo() == m_hashes[i]) + return false; + } + } + + return false; // equal (?!?) } - } + private: + std::vector<std::string> m_ciphers, m_hashes, m_kex, m_sigs; - if(use_edh_dsa) - { - suites.push_back(TLS_DHE_DSS_WITH_AES_256_CBC_SHA256); - suites.push_back(TLS_DHE_DSS_WITH_AES_128_CBC_SHA256); + }; - suites.push_back(TLS_DHE_DSS_WITH_AES_256_CBC_SHA); - suites.push_back(TLS_DHE_DSS_WITH_AES_128_CBC_SHA); +} - suites.push_back(TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA); - suites.push_back(TLS_DHE_DSS_WITH_SEED_CBC_SHA); - } +std::vector<u16bit> TLS_Policy::ciphersuite_list(bool have_srp) const + { + std::vector<std::string> ciphers = allowed_ciphers(); + std::vector<std::string> hashes = allowed_hashes(); + std::vector<std::string> kex = allowed_key_exchange_methods(); + std::vector<std::string> sigs = allowed_signature_methods(); - if(use_edh_rsa) + if(!have_srp) { - suites.push_back(TLS_DHE_RSA_WITH_AES_256_CBC_SHA256); - suites.push_back(TLS_DHE_RSA_WITH_AES_128_CBC_SHA256); - - suites.push_back(TLS_DHE_RSA_WITH_AES_256_CBC_SHA); - suites.push_back(TLS_DHE_RSA_WITH_AES_128_CBC_SHA); + std::vector<std::string>::iterator i = std::find(kex.begin(), kex.end(), "SRP"); - suites.push_back(TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA); - suites.push_back(TLS_DHE_RSA_WITH_SEED_CBC_SHA); + if(i != kex.end()) + kex.erase(i); } - if(use_rsa) - { - suites.push_back(TLS_RSA_WITH_AES_256_CBC_SHA256); - suites.push_back(TLS_RSA_WITH_AES_128_CBC_SHA256); + Ciphersuite_Preference_Ordering order(ciphers, hashes, kex, sigs); - suites.push_back(TLS_RSA_WITH_AES_256_CBC_SHA); - suites.push_back(TLS_RSA_WITH_AES_128_CBC_SHA); + std::map<TLS_Ciphersuite, u16bit, Ciphersuite_Preference_Ordering> ciphersuites(order); - suites.push_back(TLS_RSA_WITH_3DES_EDE_CBC_SHA); - suites.push_back(TLS_RSA_WITH_SEED_CBC_SHA); - - suites.push_back(TLS_RSA_WITH_RC4_128_SHA); - suites.push_back(TLS_RSA_WITH_RC4_128_MD5); + // When in doubt use brute force :) + for(u32bit i = 0; i != 65536; ++i) + { + TLS_Ciphersuite suite = TLS_Ciphersuite::lookup_ciphersuite(i); + if(suite.cipher_keylen() == 0) + continue; // not a ciphersuite we know + + if(value_exists(ciphers, suite.cipher_algo()) && + value_exists(hashes, suite.mac_algo()) && + value_exists(kex, suite.kex_algo()) && + value_exists(sigs, suite.sig_algo())) + { + ciphersuites[suite] = i; + } } - if(suites.size() == 0) - throw TLS_Exception(INTERNAL_ERROR, - "TLS_Policy error: All ciphersuites disabled"); + std::vector<u16bit> ciphersuite_codes; + + for(std::map<TLS_Ciphersuite, u16bit, Ciphersuite_Preference_Ordering>::iterator i = ciphersuites.begin(); + i != ciphersuites.end(); ++i) + { + ciphersuite_codes.push_back(i->second); + } - return suites; + return ciphersuite_codes; } /* @@ -105,23 +176,30 @@ std::vector<byte> TLS_Policy::compression() const /* * Choose which ciphersuite to use */ -u16bit TLS_Policy::choose_suite(const std::vector<u16bit>& c_suites, +u16bit TLS_Policy::choose_suite(const std::vector<u16bit>& client_suites, bool have_rsa, bool have_dsa, bool have_srp) const { - const bool use_static_rsa = allow_static_rsa() && have_rsa; - const bool use_edh_rsa = allow_edh_rsa() && have_rsa; - const bool use_edh_dsa = allow_edh_dsa() && have_dsa; - const bool use_srp = allow_srp() && have_srp; - - std::vector<u16bit> s_suites = suite_list(use_static_rsa, use_edh_rsa, - use_edh_dsa, use_srp); - - for(size_t i = 0; i != s_suites.size(); ++i) - for(size_t j = 0; j != c_suites.size(); ++j) - if(s_suites[i] == c_suites[j]) - return s_suites[i]; + for(size_t i = 0; i != client_suites.size(); ++i) + { + u16bit suite_id = client_suites[i]; + TLS_Ciphersuite suite = TLS_Ciphersuite::lookup_ciphersuite(suite_id); + if(suite.cipher_keylen() == 0) + continue; // not a ciphersuite we know + + if(!have_srp && suite.kex_algo() == "SRP") + continue; + + if(suite.sig_algo() == "RSA" && have_rsa) + return suite_id; + else if(suite.sig_algo() == "DSA" && have_dsa) + return suite_id; +#if 0 + else if(suite.sig_algo() == "") // anonymous server + return suite_id; +#endif + } return 0; } @@ -141,12 +219,4 @@ byte TLS_Policy::choose_compression(const std::vector<byte>& c_comp) const return NO_COMPRESSION; } -/* -* Return the group to use for empheral DH -*/ -DL_Group TLS_Policy::dh_group() const - { - return DL_Group("modp/ietf/1024"); - } - } |