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/*
* Finished Message
* (C) 2004-2006,2012 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/tls_messages.h>
#include <botan/kdf.h>
#include <botan/internal/tls_handshake_io.h>
#include <botan/internal/tls_handshake_state.h>
namespace Botan {
namespace TLS {
namespace {
/*
* Compute the verify_data
*/
std::vector<uint8_t> finished_compute_verify(const Handshake_State& state,
Connection_Side side)
{
const uint8_t TLS_CLIENT_LABEL[] = {
0x63, 0x6C, 0x69, 0x65, 0x6E, 0x74, 0x20, 0x66, 0x69, 0x6E, 0x69,
0x73, 0x68, 0x65, 0x64 };
const uint8_t TLS_SERVER_LABEL[] = {
0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x66, 0x69, 0x6E, 0x69,
0x73, 0x68, 0x65, 0x64 };
std::unique_ptr<KDF> prf(state.protocol_specific_prf());
std::vector<uint8_t> input;
std::vector<uint8_t> label;
if(side == CLIENT)
label += std::make_pair(TLS_CLIENT_LABEL, sizeof(TLS_CLIENT_LABEL));
else
label += std::make_pair(TLS_SERVER_LABEL, sizeof(TLS_SERVER_LABEL));
input += state.hash().final(state.version(), state.ciphersuite().prf_algo());
return unlock(prf->derive_key(12, state.session_keys().master_secret(), input, label));
}
}
/*
* Create a new Finished message
*/
Finished::Finished(Handshake_IO& io,
Handshake_State& state,
Connection_Side side) : m_verification_data(finished_compute_verify( state, side ))
{
state.hash().update(io.send(*this));
}
/*
* Serialize a Finished message
*/
std::vector<uint8_t> Finished::serialize() const
{
return m_verification_data;
}
/*
* Deserialize a Finished message
*/
Finished::Finished(const std::vector<uint8_t>& buf) : m_verification_data(buf)
{}
/*
* Verify a Finished message
*/
bool Finished::verify(const Handshake_State& state,
Connection_Side side) const
{
std::vector<byte> computed_verify = finished_compute_verify(state, side);
#if defined(BOTAN_UNSAFE_FUZZER_MODE)
return true;
#else
return (m_verification_data.size() == computed_verify.size()) &&
constant_time_compare(m_verification_data.data(), computed_verify.data(), computed_verify.size());
#endif
}
}
}
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