diff options
Diffstat (limited to 'src/tls/tls_session_key.cpp')
-rw-r--r-- | src/tls/tls_session_key.cpp | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/src/tls/tls_session_key.cpp b/src/tls/tls_session_key.cpp new file mode 100644 index 000000000..edd0617bc --- /dev/null +++ b/src/tls/tls_session_key.cpp @@ -0,0 +1,89 @@ +/* +* TLS Session Key +* (C) 2004-2006,2011 Jack Lloyd +* +* Released under the terms of the Botan license +*/ + +#include <botan/internal/tls_session_key.h> +#include <botan/internal/tls_handshake_state.h> +#include <botan/internal/tls_messages.h> +#include <botan/lookup.h> +#include <memory> + +namespace Botan { + +namespace TLS { + +/** +* Session_Keys Constructor +*/ +Session_Keys::Session_Keys(Handshake_State* state, + const MemoryRegion<byte>& pre_master_secret, + bool resuming) + { + const size_t mac_keylen = output_length_of(state->suite.mac_algo()); + const size_t cipher_keylen = state->suite.cipher_keylen(); + + size_t cipher_ivlen = 0; + if(have_block_cipher(state->suite.cipher_algo())) + cipher_ivlen = block_size_of(state->suite.cipher_algo()); + + const size_t prf_gen = 2 * (mac_keylen + cipher_keylen + cipher_ivlen); + + const byte MASTER_SECRET_MAGIC[] = { + 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x20, 0x73, 0x65, 0x63, 0x72, 0x65, 0x74 }; + + const byte KEY_GEN_MAGIC[] = { + 0x6B, 0x65, 0x79, 0x20, 0x65, 0x78, 0x70, 0x61, 0x6E, 0x73, 0x69, 0x6F, 0x6E }; + + std::auto_ptr<KDF> prf(state->protocol_specific_prf()); + + if(resuming) + { + master_sec = pre_master_secret; + } + else + { + SecureVector<byte> salt; + + if(state->version() != Protocol_Version::SSL_V3) + salt += std::make_pair(MASTER_SECRET_MAGIC, sizeof(MASTER_SECRET_MAGIC)); + + salt += state->client_hello->random(); + salt += state->server_hello->random(); + + master_sec = prf->derive_key(48, pre_master_secret, salt); + } + + SecureVector<byte> salt; + if(state->version() != Protocol_Version::SSL_V3) + salt += std::make_pair(KEY_GEN_MAGIC, sizeof(KEY_GEN_MAGIC)); + salt += state->server_hello->random(); + salt += state->client_hello->random(); + + SymmetricKey keyblock = prf->derive_key(prf_gen, master_sec, salt); + + const byte* key_data = keyblock.begin(); + + c_mac = SymmetricKey(key_data, mac_keylen); + key_data += mac_keylen; + + s_mac = SymmetricKey(key_data, mac_keylen); + key_data += mac_keylen; + + c_cipher = SymmetricKey(key_data, cipher_keylen); + key_data += cipher_keylen; + + s_cipher = SymmetricKey(key_data, cipher_keylen); + key_data += cipher_keylen; + + c_iv = InitializationVector(key_data, cipher_ivlen); + key_data += cipher_ivlen; + + s_iv = InitializationVector(key_data, cipher_ivlen); + } + +} + +} |