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/*
* 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>
namespace Botan {
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
*/
TLS_Handshake_State::TLS_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;
kex_pub = 0;
kex_priv = 0;
version = SSL_V3;
hand_expecting_mask = 0;
hand_received_mask = 0;
}
void TLS_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 TLS_Handshake_State::set_expected_next(Handshake_Type handshake_msg)
{
hand_expecting_mask |= bitmask_for_handshake_type(handshake_msg);
}
bool TLS_Handshake_State::received_handshake_msg(Handshake_Type handshake_msg) const
{
const u32bit mask = bitmask_for_handshake_type(handshake_msg);
return (hand_received_mask & mask);
}
std::pair<std::string, Signature_Format>
TLS_Handshake_State::choose_sig_format(const Private_Key* key,
std::string& hash_algo,
std::string& sig_algo,
bool for_client_auth)
{
sig_algo = key->algo_name();
/*
FIXME: This should respect the algo preferences in the client hello
(or certificate request, depending on value of for_client_auth).
*/
if(sig_algo == "RSA")
{
if(for_client_auth && this->version == SSL_V3)
{
hash_algo = "Raw";
}
else if(this->version < TLS_V12)
{
hash_algo = "TLS.Digest.0";
}
else
{
hash_algo = "SHA-256"; // should be policy
}
const std::string padding = "EMSA3(" + hash_algo + ")";
return std::make_pair(padding, IEEE_1363);
}
else if(sig_algo == "DSA")
{
if(for_client_auth && this->version == SSL_V3)
{
hash_algo = "Raw";
}
else if(this->version < TLS_V12)
{
hash_algo = "SHA-1";
}
else
{
hash_algo = "SHA-1"; // should be policy
}
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>
TLS_Handshake_State::choose_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();
if(this->version < TLS_V12)
{
if(hash_algo != "")
throw Decoding_Error("Counterparty sent hash/sig IDs with old version");
}
if(sig_algo != "" && sig_algo != algo_name)
throw Decoding_Error("Counterparty sent inconsistent key and sig types");
if(algo_name == "RSA")
{
if(for_client_auth && this->version == SSL_V3)
{
hash_algo = "Raw";
}
else if(this->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")
{
if(for_client_auth && this->version == SSL_V3)
{
hash_algo = "Raw";
}
else if(this->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
*/
TLS_Handshake_State::~TLS_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;
delete kex_pub;
delete kex_priv;
}
}
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