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Diffstat (limited to 'src/tls/tls_handshake_state.cpp')
| -rw-r--r-- | src/tls/tls_handshake_state.cpp | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/src/tls/tls_handshake_state.cpp b/src/tls/tls_handshake_state.cpp new file mode 100644 index 000000000..9087031b6 --- /dev/null +++ b/src/tls/tls_handshake_state.cpp @@ -0,0 +1,293 @@ +/* +* TLS Handshaking +* (C) 2004-2006,2011 Jack Lloyd +* +* Released under the terms of the Botan license +*/ + +#include <botan/internal/tls_handshake_state.h> +#include <botan/internal/tls_messages.h> +#include <botan/internal/assert.h> +#include <botan/lookup.h> + +namespace Botan { + +namespace TLS { + +namespace { + +u32bit bitmask_for_handshake_type(Handshake_Type type) + { + switch(type) + { + case HELLO_REQUEST: + return (1 << 0); + + /* + * Same code point for both client hello styles + */ + case CLIENT_HELLO: + case CLIENT_HELLO_SSLV2: + return (1 << 1); + + case SERVER_HELLO: + return (1 << 2); + + case CERTIFICATE: + return (1 << 3); + + case SERVER_KEX: + return (1 << 4); + + case CERTIFICATE_REQUEST: + return (1 << 5); + + case SERVER_HELLO_DONE: + return (1 << 6); + + case CERTIFICATE_VERIFY: + return (1 << 7); + + case CLIENT_KEX: + return (1 << 8); + + case NEXT_PROTOCOL: + return (1 << 9); + + case HANDSHAKE_CCS: + return (1 << 10); + + case FINISHED: + return (1 << 11); + + // allow explicitly disabling new handshakes + case HANDSHAKE_NONE: + return 0; + + default: + throw Internal_Error("Unknown handshake type " + to_string(type)); + } + + return 0; + } + +} + +/* +* Initialize the SSL/TLS Handshake State +*/ +Handshake_State::Handshake_State() + { + client_hello = 0; + server_hello = 0; + server_certs = 0; + server_kex = 0; + cert_req = 0; + server_hello_done = 0; + next_protocol = 0; + + client_certs = 0; + client_kex = 0; + client_verify = 0; + client_finished = 0; + server_finished = 0; + + server_rsa_kex_key = 0; + + version = Protocol_Version::SSL_V3; + + hand_expecting_mask = 0; + hand_received_mask = 0; + } + +void Handshake_State::confirm_transition_to(Handshake_Type handshake_msg) + { + const u32bit mask = bitmask_for_handshake_type(handshake_msg); + + hand_received_mask |= mask; + + const bool ok = (hand_expecting_mask & mask); // overlap? + + if(!ok) + throw Unexpected_Message("Unexpected state transition in handshake, got " + + to_string(handshake_msg) + " mask is " + + to_string(hand_expecting_mask)); + + /* We don't know what to expect next, so force a call to + set_expected_next; if it doesn't happen, the next transition + check will always fail which is what we want. + */ + hand_expecting_mask = 0; + } + +void Handshake_State::set_expected_next(Handshake_Type handshake_msg) + { + hand_expecting_mask |= bitmask_for_handshake_type(handshake_msg); + } + +bool Handshake_State::received_handshake_msg(Handshake_Type handshake_msg) const + { + const u32bit mask = bitmask_for_handshake_type(handshake_msg); + + return (hand_received_mask & mask); + } + +KDF* Handshake_State::protocol_specific_prf() + { + if(version == Protocol_Version::SSL_V3) + { + return get_kdf("SSL3-PRF"); + } + else if(version == Protocol_Version::TLS_V10 || version == Protocol_Version::TLS_V11) + { + return get_kdf("TLS-PRF"); + } + else if(version == Protocol_Version::TLS_V12) + { + if(suite.mac_algo() == "SHA-1" || suite.mac_algo() == "SHA-256") + return get_kdf("TLS-12-PRF(SHA-256)"); + + return get_kdf("TLS-12-PRF(" + suite.mac_algo() + ")"); + } + + throw Internal_Error("Unknown version code " + version.to_string()); + } + +std::pair<std::string, Signature_Format> +Handshake_State::choose_sig_format(const Private_Key* key, + std::string& hash_algo_out, + std::string& sig_algo_out, + bool for_client_auth) + { + const std::string sig_algo = key->algo_name(); + + const std::vector<std::pair<std::string, std::string> > supported_algos = + (for_client_auth) ? cert_req->supported_algos() : client_hello->supported_algos(); + + std::string hash_algo; + + for(size_t i = 0; i != supported_algos.size(); ++i) + { + if(supported_algos[i].second == sig_algo) + { + hash_algo = supported_algos[i].first; + break; + } + } + + if(for_client_auth && this->version == Protocol_Version::SSL_V3) + hash_algo = "Raw"; + + if(hash_algo == "" && this->version == Protocol_Version::TLS_V12) + hash_algo = "SHA-1"; // TLS 1.2 but no compatible hashes set (?) + + BOTAN_ASSERT(hash_algo != "", "Couldn't figure out hash to use"); + + if(this->version >= Protocol_Version::TLS_V12) + { + hash_algo_out = hash_algo; + sig_algo_out = sig_algo; + } + + if(sig_algo == "RSA") + { + const std::string padding = "EMSA3(" + hash_algo + ")"; + + return std::make_pair(padding, IEEE_1363); + } + else if(sig_algo == "DSA" || sig_algo == "ECDSA") + { + const std::string padding = "EMSA1(" + hash_algo + ")"; + + return std::make_pair(padding, DER_SEQUENCE); + } + + throw Invalid_Argument(sig_algo + " is invalid/unknown for TLS signatures"); + } + +std::pair<std::string, Signature_Format> +Handshake_State::understand_sig_format(const Public_Key* key, + std::string hash_algo, + std::string sig_algo, + bool for_client_auth) + { + const std::string algo_name = key->algo_name(); + + /* + FIXME: This should check what was sent against the client hello + preferences, or the certificate request, to ensure it was allowed + by those restrictions. + + Or not? + */ + + if(this->version < Protocol_Version::TLS_V12) + { + if(hash_algo != "" || sig_algo != "") + throw Decoding_Error("Counterparty sent hash/sig IDs with old version"); + } + else + { + if(hash_algo == "") + throw Decoding_Error("Counterparty did not send hash/sig IDS"); + + if(sig_algo != algo_name) + throw Decoding_Error("Counterparty sent inconsistent key and sig types"); + } + + if(algo_name == "RSA") + { + if(for_client_auth && this->version == Protocol_Version::SSL_V3) + { + hash_algo = "Raw"; + } + else if(this->version < Protocol_Version::TLS_V12) + { + hash_algo = "TLS.Digest.0"; + } + + const std::string padding = "EMSA3(" + hash_algo + ")"; + return std::make_pair(padding, IEEE_1363); + } + else if(algo_name == "DSA" || algo_name == "ECDSA") + { + if(algo_name == "DSA" && for_client_auth && this->version == Protocol_Version::SSL_V3) + { + hash_algo = "Raw"; + } + else if(this->version < Protocol_Version::TLS_V12) + { + hash_algo = "SHA-1"; + } + + const std::string padding = "EMSA1(" + hash_algo + ")"; + + return std::make_pair(padding, DER_SEQUENCE); + } + + throw Invalid_Argument(algo_name + " is invalid/unknown for TLS signatures"); + } + +/* +* Destroy the SSL/TLS Handshake State +*/ +Handshake_State::~Handshake_State() + { + delete client_hello; + delete server_hello; + delete server_certs; + delete server_kex; + delete cert_req; + delete server_hello_done; + delete next_protocol; + + delete client_certs; + delete client_kex; + delete client_verify; + delete client_finished; + delete server_finished; + } + +} + +} |