GEANTLink/lib/TLS/src/Method.cpp

1836 lines
85 KiB
C++

/*
Copyright 2015-2016 Amebis
Copyright 2016 GÉANT
This file is part of GÉANTLink.
GÉANTLink is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
GÉANTLink is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GÉANTLink. If not, see <http://www.gnu.org/licenses/>.
*/
#include "StdAfx.h"
#if EAP_TLS >= EAP_TLS_SCHANNEL
#pragma comment(lib, "Secur32.lib")
#endif
using namespace std;
using namespace winstd;
//////////////////////////////////////////////////////////////////////
// Data
//////////////////////////////////////////////////////////////////////
#if EAP_TLS < EAP_TLS_SCHANNEL
static const unsigned char s_cipher_suite[] = {
//0xc0, 0x28, // ECDHE-RSA-AES256-SHA384 Kx=ECDH Au=RSA Enc=AES(256) Mac=SHA384
//0xc0, 0x24, // ECDHE-ECDSA-AES256-SHA384 Kx=ECDH Au=ECDSA Enc=AES(256) Mac=SHA384
0x00, 0x3d, // AES256-SHA256 Kx=RSA Au=RSA Enc=AES(256) Mac=SHA256
//0x00, 0x6b, // DHE-RSA-AES256-SHA256 Kx=DH Au=RSA Enc=AES(256) Mac=SHA256
//0x00, 0x6a, // DHE-DSS-AES256-SHA256 Kx=DH Au=DSS Enc=AES(256) Mac=SHA256
//0xc0, 0x27, // ECDHE-RSA-AES128-SHA256 Kx=ECDH Au=RSA Enc=AES(128) Mac=SHA256
//0xc0, 0x23, // ECDHE-ECDSA-AES128-SHA256 Kx=ECDH Au=ECDSA Enc=AES(128) Mac=SHA256
0x00, 0x3c, // AES128-SHA256 Kx=RSA Au=RSA Enc=AES(128) Mac=SHA256
//0x00, 0x67, // DHE-RSA-AES128-SHA256 Kx=DH Au=RSA Enc=AES(128) Mac=SHA256
//0x00, 0x40, // DHE-DSS-AES128-SHA256 Kx=DH Au=DSS Enc=AES(128) Mac=SHA256
// Backward compatibility ciphers
0x00, 0x2f, // TLS_RSA_WITH_AES_128_CBC_SHA (required by TLS 1.2)
0x00, 0x0a, // TLS_RSA_WITH_3DES_EDE_CBC_SHA (required by EAP-TLS)
};
static const unsigned char s_compression_suite[] = {
0x00, // No compression
};
#endif
//////////////////////////////////////////////////////////////////////
// eap::method_tls
//////////////////////////////////////////////////////////////////////
eap::method_tls::method_tls(_In_ module &module, _In_ config_method_tls &cfg, _In_ credentials_tls &cred) :
m_cfg(cfg),
m_cred(cred),
m_user_ctx(NULL),
#if EAP_TLS < EAP_TLS_SCHANNEL
m_session_resumed(false),
m_phase(phase_unknown),
m_seq_num_client(0),
m_seq_num_server(0),
#else
m_phase(phase_unknown),
#endif
method(module, cfg, cred)
{
#if EAP_TLS < EAP_TLS_SCHANNEL
m_tls_version = tls_version_1_2;
#ifdef _DEBUG
memset(m_handshake, 0, sizeof(m_handshake));
#endif
#endif
}
eap::method_tls::method_tls(_Inout_ method_tls &&other) :
m_cred ( other.m_cred ),
m_cfg ( other.m_cfg ),
m_user_ctx (std::move(other.m_user_ctx )),
m_packet_req (std::move(other.m_packet_req )),
m_packet_res (std::move(other.m_packet_res )),
m_key_mppe_client (std::move(other.m_key_mppe_client )),
m_key_mppe_server (std::move(other.m_key_mppe_server )),
#if EAP_TLS < EAP_TLS_SCHANNEL
m_cp (std::move(other.m_cp )),
m_cp_enc_client (std::move(other.m_cp_enc_client )),
m_cp_enc_server (std::move(other.m_cp_enc_server )),
m_key_exp1 (std::move(other.m_key_exp1 )),
m_tls_version (std::move(other.m_tls_version )),
m_alg_prf (std::move(other.m_alg_prf )),
m_state_client (std::move(other.m_state_client )),
m_state_client_pending (std::move(other.m_state_client_pending )),
m_state_server (std::move(other.m_state_server )),
m_state_server_pending (std::move(other.m_state_server_pending )),
m_master_secret (std::move(other.m_master_secret )),
m_random_client (std::move(other.m_random_client )),
m_random_server (std::move(other.m_random_server )),
m_session_id (std::move(other.m_session_id )),
m_session_resumed (std::move(other.m_session_resumed )),
m_server_cert_chain (std::move(other.m_server_cert_chain )),
m_hash_handshake_msgs_md5 (std::move(other.m_hash_handshake_msgs_md5 )),
m_hash_handshake_msgs_sha1 (std::move(other.m_hash_handshake_msgs_sha1 )),
m_hash_handshake_msgs_sha256(std::move(other.m_hash_handshake_msgs_sha256)),
m_phase (std::move(other.m_phase )),
m_seq_num_client (std::move(other.m_seq_num_client )),
m_seq_num_server (std::move(other.m_seq_num_server )),
#else
m_sc_target_name (std::move(other.m_sc_target_name )),
m_sc_cred (std::move(other.m_sc_cred )),
m_sc_queue (std::move(other.m_sc_queue )),
m_sc_ctx (std::move(other.m_sc_ctx )),
m_phase (std::move(other.m_phase )),
#endif
method (std::move(other ))
{
#if EAP_TLS < EAP_TLS_SCHANNEL
memcpy(m_handshake, other.m_handshake, sizeof(m_handshake));
#ifdef _DEBUG
memset(other.m_handshake, 0, sizeof(m_handshake));
#endif
#endif
}
eap::method_tls& eap::method_tls::operator=(_Inout_ method_tls &&other)
{
if (this != std::addressof(other)) {
assert(std::addressof(m_cred) == std::addressof(other.m_cred)); // Move method with same credentials only!
(method&)*this = std::move(other );
m_user_ctx = std::move(other.m_user_ctx );
m_packet_req = std::move(other.m_packet_req );
m_packet_res = std::move(other.m_packet_res );
m_key_mppe_client = std::move(other.m_key_mppe_client );
m_key_mppe_server = std::move(other.m_key_mppe_server );
#if EAP_TLS < EAP_TLS_SCHANNEL
m_cp = std::move(other.m_cp );
m_cp_enc_client = std::move(other.m_cp_enc_client );
m_cp_enc_server = std::move(other.m_cp_enc_server );
m_key_exp1 = std::move(other.m_key_exp1 );
m_tls_version = std::move(other.m_tls_version );
m_alg_prf = std::move(other.m_alg_prf );
m_state_client = std::move(other.m_state_client );
m_state_client_pending = std::move(other.m_state_client_pending );
m_state_server = std::move(other.m_state_server );
m_state_server_pending = std::move(other.m_state_server_pending );
m_master_secret = std::move(other.m_master_secret );
m_random_client = std::move(other.m_random_client );
m_random_server = std::move(other.m_random_server );
m_session_id = std::move(other.m_session_id );
m_session_resumed = std::move(other.m_session_resumed );
m_server_cert_chain = std::move(other.m_server_cert_chain );
m_hash_handshake_msgs_md5 = std::move(other.m_hash_handshake_msgs_md5 );
m_hash_handshake_msgs_sha1 = std::move(other.m_hash_handshake_msgs_sha1 );
m_hash_handshake_msgs_sha256 = std::move(other.m_hash_handshake_msgs_sha256);
m_phase = std::move(other.m_phase );
m_seq_num_client = std::move(other.m_seq_num_client );
m_seq_num_server = std::move(other.m_seq_num_server );
memcpy(m_handshake, other.m_handshake, sizeof(m_handshake));
#ifdef _DEBUG
memset(other.m_handshake, 0, sizeof(m_handshake));
#endif
#else
m_sc_target_name = std::move(other.m_sc_target_name );
m_sc_cred = std::move(other.m_sc_cred );
m_sc_queue = std::move(other.m_sc_queue );
m_sc_ctx = std::move(other.m_sc_ctx );
m_phase = std::move(other.m_phase );
#endif
}
return *this;
}
void eap::method_tls::begin_session(
_In_ DWORD dwFlags,
_In_ const EapAttributes *pAttributeArray,
_In_ HANDLE hTokenImpersonateUser,
_In_opt_ DWORD dwMaxSendPacketSize)
{
method::begin_session(dwFlags, pAttributeArray, hTokenImpersonateUser, dwMaxSendPacketSize);
m_user_ctx = hTokenImpersonateUser;
user_impersonator impersonating(m_user_ctx);
#if EAP_TLS < EAP_TLS_SCHANNEL
// Create cryptographics provider for support needs (handshake hashing, client random, temporary keys...).
if (!m_cp.create(NULL, NULL, PROV_RSA_AES, CRYPT_VERIFYCONTEXT))
throw win_runtime_error(__FUNCTION__ " Error creating cryptographics provider.");
// Microsoft CryptoAPI does not support importing clear text session keys.
// Therefore, we trick it to say the session key is "encrypted" with an exponent-of-one key.
if (!m_key_exp1.create_exp1(m_cp, AT_KEYEXCHANGE))
throw win_runtime_error(__FUNCTION__ " Error creating exponent-of-one key.");
// Restore previous session ID and master secret. We might get lucky.
m_session_id = m_cfg.m_session_id;
m_master_secret = m_cfg.m_master_secret;
#else
// Build (expected) server name(s) for Schannel.
m_sc_target_name.clear();
for (list<wstring>::const_iterator name = m_cfg.m_server_names.cbegin(), name_end = m_cfg.m_server_names.cend(); name != name_end; ++name) {
if (name != m_cfg.m_server_names.cbegin())
m_sc_target_name += _T(';');
#ifdef _UNICODE
m_sc_target_name.insert(m_sc_target_name.end(), name->begin(), name->end());
#else
string buf;
WideCharToMultiByte(CP_ACP, 0, name->c_str(), -1, buf, NULL, NULL);
m_sc_target_name.insert(m_sc_target_name.end(), buf.begin(), buf.end());
#endif
}
// Prepare client credentials for Schannel.
PCCERT_CONTEXT certs[] = { m_cred.m_cert ? (PCCERT_CONTEXT)m_cred.m_cert : NULL };
SCHANNEL_CRED cred = {
SCHANNEL_CRED_VERSION, // dwVersion
m_cred.m_cert ? 1 : 0, // cCreds
certs, // paCred
NULL, // hRootStore: Not valid for client credentials
0, // cMappers
NULL, // aphMappers
0, // cSupportedAlgs: Use system configured default
NULL, // palgSupportedAlgs: Use system configured default
SP_PROT_TLS1_X_CLIENT | (SP_PROT_TLS1_2_CLIENT<<2), // grbitEnabledProtocols: TLS 1.x
0, // dwMinimumCipherStrength: Use system configured default
0, // dwMaximumCipherStrength: Use system configured default
0, // dwSessionLifespan: Use system configured default = 10hr
#if EAP_TLS >= EAP_TLS_SCHANNEL_FULL
SCH_CRED_AUTO_CRED_VALIDATION | // dwFlags: Let Schannel verify server certificate
#else
SCH_CRED_MANUAL_CRED_VALIDATION | // dwFlags: Prevent Schannel verify server certificate (we want to use custom root CA store and multiple name checking)
#endif
SCH_CRED_CACHE_ONLY_URL_RETRIEVAL_ON_CREATE | // dwFlags: Do not attempt online revocation check - we do not expect to have network connection yet
SCH_CRED_IGNORE_NO_REVOCATION_CHECK | // dwFlags: Ignore no-revocation-check errors (TODO: Test if this flag is required.)
SCH_CRED_IGNORE_REVOCATION_OFFLINE | // dwFlags: Ignore offline-revocation errors - we do not expect to have network connection yet
SCH_CRED_NO_DEFAULT_CREDS | // dwFlags: If client certificate we provided is not acceptable, do not try to select one on your own
(m_cfg.m_server_names.empty() ? SCH_CRED_NO_SERVERNAME_CHECK : 0) | // dwFlags: When no expected server name is given, do not do the server name check.
0x00400000 /*SCH_USE_STRONG_CRYPTO*/, // dwFlags: Do not use broken ciphers
0 // dwCredFormat
};
SECURITY_STATUS stat = m_sc_cred.acquire(NULL, UNISP_NAME, SECPKG_CRED_OUTBOUND, NULL, &cred);
if (FAILED(stat))
throw sec_runtime_error(stat, __FUNCTION__ " Error acquiring Schannel credentials handle.");
#endif
}
void eap::method_tls::process_request_packet(
_In_bytecount_(dwReceivedPacketSize) const void *pReceivedPacket,
_In_ DWORD dwReceivedPacketSize,
_Inout_ EapPeerMethodOutput *pEapOutput)
{
assert(pReceivedPacket && dwReceivedPacketSize >= 4);
assert(pEapOutput);
// Is this a valid EAP-TLS packet?
if (dwReceivedPacketSize < 6)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Packet is too small. EAP-%s packets should be at least 6B.");
//else if (pReceivedPacket->Data[0] != eap_type_tls) // Skip method check, to allow TTLS extension.
// throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, string_printf(__FUNCTION__ " Packet is not EAP-TLS (expected: %u, received: %u).", eap_type_tls, pReceivedPacket->Data[0]));
if (!m_packet_req.append_frag((const EapPacket*)pReceivedPacket)) {
// This was not the only/last fragment. Reply with ACK packet.
m_packet_res.m_code = EapCodeResponse;
m_packet_res.m_id = ((const EapPacket*)pReceivedPacket)->Id;
m_packet_res.m_flags = 0;
m_packet_res.m_data.clear();
pEapOutput->fAllowNotifications = FALSE;
pEapOutput->action = EapPeerMethodResponseActionSend;
return;
}
if (m_packet_res.m_flags & packet_tls::flags_res_more_frag) {
// We are sending a fragmented message.
if (m_packet_req.is_ack(m_packet_res.m_id)) {
// This is the ACK of our fragmented message packet. Send the next fragment.
m_packet_res.m_id++;
pEapOutput->fAllowNotifications = FALSE;
pEapOutput->action = EapPeerMethodResponseActionSend;
return;
} else
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, string_printf(__FUNCTION__ " ACK expected, received %u-%u-%x.", m_packet_req.m_code, m_packet_req.m_id, m_packet_req.m_flags));
}
m_packet_res.m_code = EapCodeResponse;
m_packet_res.m_id = m_packet_req.m_id;
m_packet_res.m_flags = 0;
user_impersonator impersonating(m_user_ctx);
#if EAP_TLS < EAP_TLS_SCHANNEL
if (((const EapPacket*)pReceivedPacket)->Code == EapCodeRequest && (m_packet_req.m_flags & packet_tls::flags_req_start)) {
// This is the EAP-TLS start message: (re)initialize method.
m_module.log_event(&EAPMETHOD_METHOD_HANDSHAKE_START2, event_data((unsigned int)eap_type_tls), event_data::blank);
m_phase = phase_client_hello;
m_key_mppe_client.clear();
m_key_mppe_server.clear();
} else {
// Process the packet.
memset(m_handshake, 0, sizeof(m_handshake));
m_packet_res.m_data.clear();
process_packet(m_packet_req.m_data.data(), m_packet_req.m_data.size());
}
switch (m_phase) {
case phase_client_hello: {
m_tls_version = tls_version_1_2;
m_server_cert_chain.clear();
// Create handshake hashing objects.
if (!m_hash_handshake_msgs_md5.create(m_cp, CALG_MD5))
throw win_runtime_error(__FUNCTION__ " Error creating MD5 hashing object.");
if (!m_hash_handshake_msgs_sha1.create(m_cp, CALG_SHA1))
throw win_runtime_error(__FUNCTION__ " Error creating SHA-1 hashing object.");
if (!m_hash_handshake_msgs_sha256.create(m_cp, CALG_SHA_256))
throw win_runtime_error(__FUNCTION__ " Error creating SHA-256 hashing object.");
m_seq_num_client = 0;
m_seq_num_server = 0;
// Build client hello packet.
sanitizing_blob msg_client_hello(make_message(tls_message_type_handshake, make_client_hello()));
m_packet_res.m_data.insert(m_packet_res.m_data.end(), msg_client_hello.begin(), msg_client_hello.end());
m_phase = phase_server_hello;
break;
}
case phase_server_hello: {
if (!m_handshake[tls_handshake_type_server_hello])
throw win_runtime_error(__FUNCTION__ " Server did not hello back. No server random! What cipher to use?");
// Adopt server state as client pending.
// If server already send the change cipher spec, use active server state. Otherwise pending.
m_state_client_pending = m_state_server.m_alg_encrypt ? m_state_server : m_state_server_pending;
// Create cryptographics provider.
if (!m_cp_enc_client.create(NULL, m_state_client_pending.m_prov_name, m_state_client_pending.m_prov_type, CRYPT_VERIFYCONTEXT))
throw win_runtime_error(__FUNCTION__ " Error creating cryptographics provider.");
if (m_handshake[tls_handshake_type_certificate]) {
// Do we trust this server?
if (m_server_cert_chain.empty())
throw win_runtime_error(ERROR_ENCRYPTION_FAILED, __FUNCTION__ " Server sent an empty certificate (chain).");
verify_server_trust();
}
if (m_handshake[tls_handshake_type_certificate_request]) {
// Client certificate requested.
sanitizing_blob msg_client_cert(make_message(tls_message_type_handshake, make_client_cert()));
m_packet_res.m_data.insert(m_packet_res.m_data.end(), msg_client_cert.begin(), msg_client_cert.end());
}
if (m_handshake[tls_handshake_type_server_hello_done]) {
if (m_server_cert_chain.empty())
throw win_runtime_error(ERROR_ENCRYPTION_FAILED, __FUNCTION__ " Can not do a client key exchange without a server public key (missing server certificate).");
// Generate pre-master secret. PMS will get sanitized in its destructor when going out-of-scope.
// Always use latest supported version by client (not negotiated one, to detect version rollback attacks).
tls_master_secret pms(m_cp, tls_version_1_2);
// Derive master secret.
static const unsigned char s_label[] = "master secret";
sanitizing_blob seed(s_label, s_label + _countof(s_label) - 1);
seed.insert(seed.end(), (const unsigned char*)&m_random_client, (const unsigned char*)(&m_random_client + 1));
seed.insert(seed.end(), (const unsigned char*)&m_random_server, (const unsigned char*)(&m_random_server + 1));
memcpy(&m_master_secret, prf(m_cp, m_alg_prf, pms, seed, sizeof(tls_master_secret)).data(), sizeof(tls_master_secret));
// Create client key exchange message, and append to packet.
sanitizing_blob msg_client_key_exchange(make_message(tls_message_type_handshake, make_client_key_exchange(pms)));
m_packet_res.m_data.insert(m_packet_res.m_data.end(), msg_client_key_exchange.begin(), msg_client_key_exchange.end());
}
if (m_handshake[tls_handshake_type_certificate_request]) {
// TODO: Create and append client certificate verify message!
}
// Append change cipher spec to packet.
sanitizing_blob ccs(make_message(tls_message_type_change_cipher_spec, sanitizing_blob(1, 1)));
m_packet_res.m_data.insert(m_packet_res.m_data.end(), ccs.begin(), ccs.end());
// Derive client side keys.
static const unsigned char s_label[] = "key expansion";
sanitizing_blob seed(s_label, s_label + _countof(s_label) - 1);
seed.insert(seed.end(), (const unsigned char*)&m_random_server, (const unsigned char*)(&m_random_server + 1));
seed.insert(seed.end(), (const unsigned char*)&m_random_client, (const unsigned char*)(&m_random_client + 1));
sanitizing_blob key_block(prf(m_cp, m_alg_prf, m_master_secret, seed,
2*m_state_client_pending.m_size_mac_key + // client_write_MAC_secret & server_write_MAC_secret (SHA1)
2*m_state_client_pending.m_size_enc_key + // client_write_key & server_write_key
2*m_state_client_pending.m_size_enc_iv )); // client_write_IV & server_write_IV
const unsigned char *_key_block = key_block.data();
// client_write_MAC_secret
m_state_client_pending.m_padding_hmac = hmac_padding(m_cp, m_state_client_pending.m_alg_mac, _key_block, m_state_client_pending.m_size_mac_key);
_key_block += m_state_client_pending.m_size_mac_key;
// server_write_MAC_secret
_key_block += m_state_client_pending.m_size_mac_key;
// client_write_key
m_state_client_pending.m_key = create_key(m_cp_enc_client, m_state_client_pending.m_alg_encrypt, m_key_exp1, _key_block, m_state_client_pending.m_size_enc_key);
_key_block += m_state_client_pending.m_size_enc_key;
// server_write_key
_key_block += m_state_client_pending.m_size_enc_key;
if (m_state_client_pending.m_size_enc_iv && m_tls_version < tls_version_1_1) {
// client_write_IV
if (!CryptSetKeyParam(m_state_client_pending.m_key, KP_IV, _key_block, 0))
throw win_runtime_error(__FUNCTION__ " Error setting client_write_IV.");
_key_block += m_state_client_pending.m_size_enc_iv;
}
// Accept client pending state as current client state.
m_state_client = std::move(m_state_client_pending);
// Create finished message, and append to packet.
sanitizing_blob msg_finished(make_message(tls_message_type_handshake, make_finished()));
m_packet_res.m_data.insert(m_packet_res.m_data.end(), msg_finished.begin(), msg_finished.end());
// Derive challenge for inner authentication (if any).
derive_challenge();
if (m_handshake[tls_handshake_type_finished]) {
// Go to application data phase. And allow piggybacking of the first data message.
m_phase = phase_application_data;
m_session_resumed = true;
process_application_data(NULL, 0);
} else {
m_session_resumed = false;
m_phase = phase_change_cipher_spec;
m_cfg.m_last_status = config_method::status_cred_invalid; // Blame credentials if we fail beyond this point.
}
break;
}
case phase_change_cipher_spec:
// Wait in this phase until server sends change cipher spec and finish.
if (m_state_server.m_alg_encrypt && m_handshake[tls_handshake_type_finished]) {
m_phase = phase_application_data;
process_application_data(NULL, 0);
}
break;
case phase_application_data:
if (m_handshake[tls_handshake_type_hello_request])
m_phase = phase_client_hello;
}
#else
if (((const EapPacket*)pReceivedPacket)->Code == EapCodeRequest && (m_packet_req.m_flags & packet_tls::flags_req_start)) {
// This is the EAP-TLS start message: (re)initialize method.
m_module.log_event(&EAPMETHOD_METHOD_HANDSHAKE_START2, event_data((unsigned int)eap_type_tls), event_data::blank);
m_phase = phase_handshake_init;
m_key_mppe_client.clear();
m_key_mppe_server.clear();
m_sc_queue.assign(m_packet_req.m_data.begin(), m_packet_req.m_data.end());
} else
m_sc_queue.insert(m_sc_queue.end(), m_packet_req.m_data.begin(), m_packet_req.m_data.end());
switch (m_phase) {
case phase_handshake_init:
case phase_handshake_cont:
process_handshake();
break;
case phase_application_data:
process_application_data();
break;
}
#endif
pEapOutput->fAllowNotifications = TRUE;
pEapOutput->action = EapPeerMethodResponseActionSend;
// EAP-Request packet was processed. Clear its data since we use the absence of data to detect first of fragmented message packages.
m_packet_req.m_data.clear();
}
void eap::method_tls::get_response_packet(
_Inout_bytecap_(*dwSendPacketSize) void *pSendPacket,
_Inout_ DWORD *pdwSendPacketSize)
{
assert(pdwSendPacketSize);
assert(pSendPacket);
*pdwSendPacketSize = m_packet_res.get_frag((EapPacket*)pSendPacket, *pdwSendPacketSize);
}
void eap::method_tls::get_result(
_In_ EapPeerMethodResultReason reason,
_Inout_ EapPeerMethodResult *ppResult)
{
assert(ppResult);
method::get_result(reason, ppResult);
switch (reason) {
case EapPeerMethodResultSuccess: {
// Derive MSK/EMSK for line encryption.
derive_msk();
// Fill array with RADIUS attributes.
eap_attr a;
m_eap_attr.reserve(m_eap_attr.size() + 3);
a.create_ms_mppe_key(16, (LPCBYTE)&m_key_mppe_client, sizeof(tls_random));
m_eap_attr.push_back(std::move(a));
a.create_ms_mppe_key(17, (LPCBYTE)&m_key_mppe_server, sizeof(tls_random));
m_eap_attr.push_back(std::move(a));
m_eap_attr.push_back(eap_attr::blank);
#if EAP_TLS < EAP_TLS_SCHANNEL
// Update configuration with session resumption data.
m_cfg.m_session_id = m_session_id;
m_cfg.m_master_secret = m_master_secret;
#else
// Make a graceful Schannel shutdown...
// ...as a desparate attempt Schannel would resume session next time then?!
DWORD dwType = SCHANNEL_SHUTDOWN;
SecBuffer token = {
sizeof(dwType),
SECBUFFER_TOKEN,
&dwType };
SecBufferDesc token_desc = { SECBUFFER_VERSION, 1, &token };
SECURITY_STATUS status;
if (SUCCEEDED(status = ApplyControlToken(m_sc_ctx, &token_desc))) {
// Prepare output buffer(s).
SecBuffer buf_out[] = { { 0, SECBUFFER_TOKEN, NULL }, };
sec_buffer_desc buf_out_desc(buf_out, _countof(buf_out));
// Build an SSL close notify message.
status = m_sc_ctx.process(
m_sc_cred,
!m_sc_target_name.empty() ? m_sc_target_name.c_str() : NULL,
ISC_REQ_REPLAY_DETECT | ISC_REQ_SEQUENCE_DETECT | ISC_REQ_CONFIDENTIALITY | ISC_REQ_INTEGRITY | ISC_REQ_STREAM | /*ISC_REQ_USE_SUPPLIED_CREDS |*/ ISC_REQ_EXTENDED_ERROR | ISC_REQ_ALLOCATE_MEMORY,
0,
NULL,
&buf_out_desc);
if (SUCCEEDED(status))
m_packet_res.m_data.insert(m_packet_res.m_data.end(), (const unsigned char*)buf_out[0].pvBuffer, (const unsigned char*)buf_out[0].pvBuffer + buf_out[0].cbBuffer);
}
#endif
break;
}
case EapPeerMethodResultFailure:
#if EAP_TLS < EAP_TLS_SCHANNEL
// Clear session resumption data.
m_cfg.m_session_id.clear();
m_cfg.m_master_secret.clear();
#else
// TODO: Research how a Schannel session context can be cleared not to resume.
#endif
break;
}
}
#if EAP_TLS < EAP_TLS_SCHANNEL
eap::sanitizing_blob eap::method_tls::make_client_hello()
{
size_t size_data;
sanitizing_blob msg;
msg.reserve(
4 + // SSL header
(size_data =
2 + // SSL version
sizeof(tls_random) + // Client random
1 + // Session ID size
m_session_id.size() + // Session ID
2 + // Length of cypher suite list
sizeof(s_cipher_suite) + // Cipher suite list
1 + // Length of compression suite
sizeof(s_compression_suite))); // Compression suite
// SSL header
assert(size_data <= 0xffffff);
unsigned int ssl_header = htonl((tls_handshake_type_client_hello << 24) | (unsigned int)size_data);
msg.insert(msg.end(), (unsigned char*)&ssl_header, (unsigned char*)(&ssl_header + 1));
// SSL version
msg.insert(msg.end(), (unsigned char*)&m_tls_version, (unsigned char*)(&m_tls_version + 1));
// Generate client random and add it to the message
m_random_client.randomize(m_cp);
msg.insert(msg.end(), (unsigned char*)&m_random_client, (unsigned char*)(&m_random_client + 1));
// Session ID
assert(m_session_id.size() <= 32);
msg.push_back((unsigned char)m_session_id.size());
msg.insert(msg.end(), m_session_id.begin(), m_session_id.end());
// Cypher suite list
unsigned short size_cipher_suite2 = htons((unsigned short)sizeof(s_cipher_suite));
msg.insert(msg.end(), (unsigned char*)&size_cipher_suite2, (unsigned char*)(&size_cipher_suite2 + 1));
msg.insert(msg.end(), s_cipher_suite, s_cipher_suite + _countof(s_cipher_suite));
// Compression
msg.push_back((unsigned char)sizeof(s_compression_suite));
msg.insert(msg.end(), s_compression_suite, s_compression_suite + _countof(s_compression_suite));
return msg;
}
eap::sanitizing_blob eap::method_tls::make_client_cert() const
{
// Select client certificate.
PCCERT_CONTEXT cert = m_cred.m_cert ? m_cred.m_cert : NULL;
size_t size_data, size_list;
sanitizing_blob msg;
msg.reserve(
4 + // SSL header
(size_data =
3 + // Certificate list size
(size_list =
(cert ? 3 + cert->cbCertEncoded : 0)))); // Certificate (optional)
// SSL header
assert(size_data <= 0xffffff);
unsigned int ssl_header = htonl((tls_handshake_type_certificate << 24) | (unsigned int)size_data);
msg.insert(msg.end(), (unsigned char*)&ssl_header, (unsigned char*)(&ssl_header + 1));
// List size
assert(size_list <= 0xffffff);
msg.push_back((unsigned char)((size_list >> 16) & 0xff));
msg.push_back((unsigned char)((size_list >> 8) & 0xff));
msg.push_back((unsigned char)((size_list ) & 0xff));
if (cert) {
// Cert size
assert(cert->cbCertEncoded <= 0xffffff);
msg.push_back((unsigned char)((cert->cbCertEncoded >> 16) & 0xff));
msg.push_back((unsigned char)((cert->cbCertEncoded >> 8) & 0xff));
msg.push_back((unsigned char)((cert->cbCertEncoded ) & 0xff));
msg.insert(msg.end(), cert->pbCertEncoded, cert->pbCertEncoded + cert->cbCertEncoded);
}
return msg;
}
eap::sanitizing_blob eap::method_tls::make_client_key_exchange(_In_ const tls_master_secret &pms) const
{
// Encrypt pre-master key with server public key first.
sanitizing_blob pms_enc((const unsigned char*)&pms, (const unsigned char*)(&pms + 1));
crypt_key key;
if (!key.import_public(m_cp_enc_client, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, &(m_server_cert_chain.front()->pCertInfo->SubjectPublicKeyInfo)))
throw win_runtime_error(__FUNCTION__ " Error importing server's public key.");
if (!CryptEncrypt(key, NULL, TRUE, 0, pms_enc))
throw win_runtime_error(__FUNCTION__ " Error encrypting PMS.");
size_t size_data, size_pms_enc = pms_enc.size();
sanitizing_blob msg;
msg.reserve(
4 + // SSL header
(size_data =
2 + // Encrypted pre master secret size
size_pms_enc)); // Encrypted pre master secret
// SSL header
assert(size_data <= 0xffffff);
unsigned int ssl_header = htonl((tls_handshake_type_client_key_exchange << 24) | (unsigned int)size_data);
msg.insert(msg.end(), (unsigned char*)&ssl_header, (unsigned char*)(&ssl_header + 1));
// Encrypted pre master secret size
assert(size_pms_enc <= 0xffff);
msg.push_back((unsigned char)((size_pms_enc >> 8) & 0xff));
msg.push_back((unsigned char)((size_pms_enc ) & 0xff));
// Encrypted pre master secret
#ifdef _HOST_LOW_ENDIAN
std::reverse(pms_enc.begin(), pms_enc.end());
#endif
msg.insert(msg.end(), pms_enc.begin(), pms_enc.end());
return msg;
}
eap::sanitizing_blob eap::method_tls::make_finished() const
{
sanitizing_blob msg;
msg.reserve(
4 + // SSL header
12); // verify_data is 12B
// SSL header
unsigned int ssl_header = htonl((unsigned int)(tls_handshake_type_finished << 24) | 12);
msg.insert(msg.end(), (unsigned char*)&ssl_header, (unsigned char*)(&ssl_header + 1));
// Create label + hash MD5 + hash SHA-1 seed.
crypt_hash hash;
static const unsigned char s_label[] = "client finished";
sanitizing_blob seed(s_label, s_label + _countof(s_label) - 1), hash_data;
if (m_tls_version < tls_version_1_2) {
hash = m_hash_handshake_msgs_md5; // duplicate
if (!CryptGetHashParam(hash, HP_HASHVAL, hash_data, 0))
throw win_runtime_error(__FUNCTION__ " Error finishing MD5 hash calculation.");
seed.insert(seed.end(), hash_data.begin(), hash_data.end());
hash = m_hash_handshake_msgs_sha1; // duplicate
if (!CryptGetHashParam(hash, HP_HASHVAL, hash_data, 0))
throw win_runtime_error(__FUNCTION__ " Error finishing SHA-1 hash calculation.");
seed.insert(seed.end(), hash_data.begin(), hash_data.end());
} else {
hash = m_hash_handshake_msgs_sha256; // duplicate
if (!CryptGetHashParam(hash, HP_HASHVAL, hash_data, 0))
throw win_runtime_error(__FUNCTION__ " Error finishing SHA-256 hash calculation.");
seed.insert(seed.end(), hash_data.begin(), hash_data.end());
}
sanitizing_blob verify(prf(m_cp, m_alg_prf, m_master_secret, seed, 12));
msg.insert(msg.end(), verify.begin(), verify.end());
return msg;
}
eap::sanitizing_blob eap::method_tls::make_message(_In_ tls_message_type_t type, _Inout_ sanitizing_blob &&data)
{
if (type == tls_message_type_handshake)
hash_handshake(data);
if (m_state_client.m_alg_encrypt)
encrypt_message(type, data);
size_t size_data = data.size();
assert(size_data <= 0xffff);
message_header hdr = {
type, // SSL record type
{
m_tls_version.major, // SSL major version
m_tls_version.minor, // SSL minor version
},
{
// Data length (unencrypted, network byte order)
(unsigned char)((size_data >> 8) & 0xff),
(unsigned char)((size_data ) & 0xff),
}
};
sanitizing_blob msg;
msg.reserve(sizeof(message_header) + size_data);
msg.assign((const unsigned char*)&hdr, (const unsigned char*)(&hdr + 1));
msg.insert(msg.end(), data.begin(), data.end());
return msg;
}
#endif
void eap::method_tls::derive_msk()
{
const unsigned char *_key_block;
#if EAP_TLS < EAP_TLS_SCHANNEL
static const unsigned char s_label[] = "client EAP encryption";
sanitizing_blob seed(s_label, s_label + _countof(s_label) - 1);
seed.insert(seed.end(), (const unsigned char*)&m_random_client, (const unsigned char*)(&m_random_client + 1));
seed.insert(seed.end(), (const unsigned char*)&m_random_server, (const unsigned char*)(&m_random_server + 1));
sanitizing_blob key_block(prf(m_cp, m_alg_prf, m_master_secret, seed, 2*sizeof(tls_random)));
_key_block = key_block.data();
#else
// Derive MSK/EMSK for line encryption.
SecPkgContext_EapKeyBlock key_block;
SECURITY_STATUS status = QueryContextAttributes(m_sc_ctx, SECPKG_ATTR_EAP_KEY_BLOCK, &key_block);
if (FAILED(status))
throw sec_runtime_error(status, __FUNCTION__ " Error generating MSK in Schannel.");
_key_block = key_block.rgbKeys;
#endif
// MS-MPPE-Recv-Key
memcpy(&m_key_mppe_client, _key_block, sizeof(tls_random));
_key_block += sizeof(tls_random);
// MS-MPPE-Send-Key
memcpy(&m_key_mppe_server, _key_block, sizeof(tls_random));
_key_block += sizeof(tls_random);
}
void eap::method_tls::derive_challenge()
{
}
#if EAP_TLS < EAP_TLS_SCHANNEL
void eap::method_tls::process_packet(_In_bytecount_(size_pck) const void *_pck, _In_ size_t size_pck)
{
sanitizing_blob data;
for (const unsigned char *pck = (const unsigned char*)_pck, *pck_end = pck + size_pck; pck < pck_end; ) {
if (pck + 5 > pck_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Incomplete message header.");
const message_header *hdr = (const message_header*)pck;
const unsigned char
*msg = (const unsigned char*)(hdr + 1),
*msg_end = msg + ntohs(*(unsigned short*)hdr->length);
if (msg_end > pck_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Incomplete message data.");
if (hdr->version >= tls_version_1_0) {
// Process TLS message.
switch (hdr->type) {
case tls_message_type_change_cipher_spec:
if (m_state_server.m_alg_encrypt) {
sanitizing_blob msg_dec(msg, msg_end);
decrypt_message(hdr->type, msg_dec);
process_change_cipher_spec(msg_dec.data(), msg_dec.size());
} else
process_change_cipher_spec(msg, msg_end - msg);
break;
case tls_message_type_alert:
if (m_state_server.m_alg_encrypt) {
sanitizing_blob msg_dec(msg, msg_end);
decrypt_message(hdr->type, msg_dec);
process_alert(msg_dec.data(), msg_dec.size());
} else
process_alert(msg, msg_end - msg);
break;
case tls_message_type_handshake:
if (m_state_server.m_alg_encrypt) {
sanitizing_blob msg_dec(msg, msg_end);
decrypt_message(hdr->type, msg_dec);
process_handshake(msg_dec.data(), msg_dec.size());
} else
process_handshake(msg, msg_end - msg);
break;
case tls_message_type_application_data: {
if (!m_state_server.m_alg_encrypt)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Application data should be encrypted.");
sanitizing_blob msg_dec(msg, msg_end);
decrypt_message(hdr->type, msg_dec);
process_application_data(msg_dec.data(), msg_dec.size());
break;
}
}
}
pck = msg_end;
}
}
void eap::method_tls::process_change_cipher_spec(_In_bytecount_(size_msg) const void *_msg, _In_ size_t size_msg)
{
if (size_msg < 1)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Incomplete change cipher spec.");
const unsigned char *msg = (const unsigned char*)_msg;
if (msg[0] != 1)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, string_printf(__FUNCTION__ " Invalid change cipher spec message (expected 1, received %u).", msg[0]));
m_module.log_event(&EAPMETHOD_TLS_CHANGE_CIPHER_SPEC, event_data((unsigned int)eap_type_tls), event_data::blank);
if (!m_state_server_pending.m_alg_encrypt)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Change cipher spec received without cipher being negotiated first.");
// Create cryptographics provider (based on server selected cipher?).
if (!m_cp_enc_server.create(NULL, m_state_server_pending.m_prov_name, m_state_server_pending.m_prov_type))
throw win_runtime_error(__FUNCTION__ " Error creating cryptographics provider.");
static const unsigned char s_label[] = "key expansion";
sanitizing_blob seed(s_label, s_label + _countof(s_label) - 1);
seed.insert(seed.end(), (const unsigned char*)&m_random_server, (const unsigned char*)(&m_random_server + 1));
seed.insert(seed.end(), (const unsigned char*)&m_random_client, (const unsigned char*)(&m_random_client + 1));
sanitizing_blob key_block(prf(m_cp, m_alg_prf, m_master_secret, seed,
2*m_state_server_pending.m_size_mac_key + // client_write_MAC_secret & server_write_MAC_secret (SHA1)
2*m_state_server_pending.m_size_enc_key + // client_write_key & server_write_key
2*m_state_server_pending.m_size_enc_iv )); // client_write_IV & server_write_IV
const unsigned char *_key_block = key_block.data();
// client_write_MAC_secret
_key_block += m_state_server_pending.m_size_mac_key;
// server_write_MAC_secret
m_state_server_pending.m_padding_hmac = hmac_padding(m_cp, m_state_server_pending.m_alg_mac, _key_block, m_state_server_pending.m_size_mac_key);
_key_block += m_state_server_pending.m_size_mac_key;
// client_write_key
_key_block += m_state_server_pending.m_size_enc_key;
// server_write_key
m_state_server_pending.m_key = create_key(m_cp_enc_server, m_state_server_pending.m_alg_encrypt, m_key_exp1, _key_block, m_state_server_pending.m_size_enc_key);
_key_block += m_state_server_pending.m_size_enc_key;
if (m_state_server_pending.m_size_enc_iv && m_tls_version < tls_version_1_1) {
// client_write_IV
_key_block += m_state_server_pending.m_size_enc_iv;
// server_write_IV
if (!CryptSetKeyParam(m_state_server_pending.m_key, KP_IV, _key_block, 0))
throw win_runtime_error(__FUNCTION__ " Error setting server_write_IV.");
_key_block += m_state_server_pending.m_size_enc_iv;
}
// Accept server pending state as current server state.
m_state_server = std::move(m_state_server_pending);
m_state_server_pending.m_alg_encrypt = 0; // Explicitly invalidate server pending state. (To mark that server must re-negotiate cipher.)
}
void eap::method_tls::process_alert(_In_bytecount_(size_msg) const void *_msg, _In_ size_t size_msg)
{
if (size_msg < 2)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Incomplete alert.");
const unsigned char *msg = (const unsigned char*)_msg;
m_module.log_event(&EAPMETHOD_TLS_ALERT, event_data((unsigned int)eap_type_tls), event_data((unsigned char)msg[0]), event_data((unsigned char)msg[1]), event_data::blank);
//if (msg[0] == alert_level_fatal) {
// // Clear session ID to avoid reconnection attempts.
// m_session_id.clear();
//}
}
void eap::method_tls::process_handshake(_In_bytecount_(size_msg) const void *_msg, _In_ size_t size_msg)
{
for (const unsigned char *msg = (const unsigned char*)_msg, *msg_end = msg + size_msg; msg < msg_end; ) {
// Parse record header.
if (msg + sizeof(unsigned int) > msg_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Incomplete record header.");
unsigned int hdr = ntohl(*(unsigned int*)msg);
const unsigned char
*rec = msg + sizeof(unsigned int),
*rec_end = rec + (hdr & 0xffffff);
if (rec_end > msg_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Incomplete record data.");
// Process record.
tls_handshake_type_t type = (tls_handshake_type_t)((hdr >> 24) & 0xff);
switch (type) {
case tls_handshake_type_server_hello:
// TLS version
if (rec + 2 > rec_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Server SSL/TLS version missing or incomplete.");
else if (*(tls_version*)rec < tls_version_1_0 || m_tls_version < *(tls_version*)rec)
throw win_runtime_error(ERROR_NOT_SUPPORTED, __FUNCTION__ " Unsupported SSL/TLS version.");
m_tls_version = *(tls_version*)rec;
m_alg_prf = m_tls_version < tls_version_1_2 ? CALG_TLS1PRF : CALG_SHA_256;
rec += 2;
// Server random
if (rec + sizeof(tls_random) > rec_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Server random missing or incomplete.");
memcpy(&m_random_server, rec, sizeof(tls_random));
rec += sizeof(tls_random);
// Session ID
if (rec + 1 > rec_end || rec + 1 + rec[0] > rec_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Session ID missing or incomplete.");
assert(rec[0] <= 32); // According to RFC 5246 session IDs should not be longer than 32B.
if (m_session_id.size() != rec[0] || memcmp(m_session_id.data(), rec + 1, rec[0]) != 0) {
m_module.log_event(&EAPMETHOD_TLS_SESSION_NEW, event_data((unsigned int)eap_type_tls), event_data::blank);
m_session_id.assign(rec + 1, rec + 1 + rec[0]);
} else
m_module.log_event(&EAPMETHOD_TLS_SESSION_RESUME, event_data((unsigned int)eap_type_tls), event_data::blank);
rec += rec[0] + 1;
// Cipher
if (rec + 2 > rec_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Cipher missing or incomplete.");
// Verify the server selected one of our ciphers.
for (size_t i = 0; ; i += 2) {
if (i < _countof(s_cipher_suite)) {
if (s_cipher_suite[i] == rec[0] && s_cipher_suite[i + 1] == rec[1])
break;
} else
throw win_runtime_error(ERROR_NOT_SUPPORTED, string_printf(__FUNCTION__ " Other than requested cipher selected (received 0x%02x%02x).", rec[0], rec[1]));
}
m_state_server_pending.set_cipher(rec);
rec += 2;
// Compression
if (rec + 1 > rec_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Compression missing or incomplete.");
// Verify the server selected one of our compression schemes.
for (size_t i = 0; ; i++) {
if (i < _countof(s_compression_suite)) {
if (s_compression_suite[i] == rec[0])
break;
} else
throw win_runtime_error(ERROR_NOT_SUPPORTED, string_printf(__FUNCTION__ " Other than requested compression selected (received 0x%02).", rec[0]));
}
rec++;
m_module.log_event(&EAPMETHOD_TLS_SERVER_HELLO1,
event_data((unsigned int)eap_type_tls),
event_data(((unsigned int)m_tls_version.major << 8) | (unsigned int)m_tls_version.minor),
event_data((unsigned int)m_session_id.size()),
event_data(m_session_id.data(), (ULONG)m_session_id.size()),
event_data::blank);
break;
case tls_handshake_type_certificate: {
// Certificate list size
if (rec + 3 > rec_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Certificate list size missing or incomplete.");
const unsigned char
*list = rec + 3,
*list_end = list + ((rec[0] << 16) | (rec[1] << 8) | rec[2]);
if (list_end > rec_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Certificate list missing or incomplete.");
m_server_cert_chain.clear();
while (list < list_end) {
// Certificate size
if (list + 3 > list_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Certificate size missing or incomplete.");
const unsigned char
*cert = list + 3,
*cert_end = cert + ((list[0] << 16) | (list[1] << 8) | list[2]);
if (cert_end > list_end)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Certificate rec missing or incomplete.");
// Certificate
cert_context c;
if (!c.create(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, cert, (DWORD)(cert_end - cert)))
throw win_runtime_error(__FUNCTION__ " Error reading certificate.");
m_server_cert_chain.push_back(std::move(c));
list = cert_end;
}
wstring cert_name(!m_server_cert_chain.empty() ? get_cert_title(m_server_cert_chain.front()) : L"<blank>");
m_module.log_event(&EAPMETHOD_TLS_CERTIFICATE, event_data((unsigned int)eap_type_tls), event_data(cert_name), event_data::blank);
break;
}
case tls_handshake_type_certificate_request:
m_module.log_event(&EAPMETHOD_TLS_CERTIFICATE_REQUEST, event_data((unsigned int)eap_type_tls), event_data::blank);
break;
case tls_handshake_type_server_hello_done:
m_module.log_event(&EAPMETHOD_TLS_SERVER_HELLO_DONE, event_data((unsigned int)eap_type_tls), event_data::blank);
break;
case tls_handshake_type_finished: {
if (!m_state_server.m_alg_encrypt)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, __FUNCTION__ " Finished message should be encrypted.");
// According to https://tools.ietf.org/html/rfc5246#section-7.4.9 all verify_data is 12B.
if (rec_end - rec != 12)
throw win_runtime_error(EAP_E_EAPHOST_METHOD_INVALID_PACKET, string_printf(__FUNCTION__ " Finished record size incorrect (expected 12B, received %uB).", rec_end - rec));
// Create label + hash MD5 + hash SHA-1 seed.
crypt_hash hash;
static const unsigned char s_label[] = "server finished";
sanitizing_blob seed(s_label, s_label + _countof(s_label) - 1), hash_data;
if (m_tls_version < tls_version_1_2) {
hash = m_hash_handshake_msgs_md5; // duplicate
if (!CryptGetHashParam(hash, HP_HASHVAL, hash_data, 0))
throw win_runtime_error(__FUNCTION__ " Error finishing MD5 hash calculation.");
seed.insert(seed.end(), hash_data.begin(), hash_data.end());
hash = m_hash_handshake_msgs_sha1; // duplicate
if (!CryptGetHashParam(hash, HP_HASHVAL, hash_data, 0))
throw win_runtime_error(__FUNCTION__ " Error finishing SHA-1 hash calculation.");
seed.insert(seed.end(), hash_data.begin(), hash_data.end());
} else {
hash = m_hash_handshake_msgs_sha256; // duplicate
if (!CryptGetHashParam(hash, HP_HASHVAL, hash_data, 0))
throw win_runtime_error(__FUNCTION__ " Error finishing SHA-256 hash calculation.");
seed.insert(seed.end(), hash_data.begin(), hash_data.end());
}
if (memcmp(prf(m_cp, m_alg_prf, m_master_secret, seed, 12).data(), rec, 12))
throw win_runtime_error(ERROR_ENCRYPTION_FAILED, __FUNCTION__ " Integrity check failed.");
m_module.log_event(&EAPMETHOD_TLS_FINISHED, event_data((unsigned int)eap_type_tls), event_data::blank);
break;
}
default:
m_module.log_event(&EAPMETHOD_TLS_HANDSHAKE_IGNORE, event_data((unsigned int)eap_type_tls), event_data((unsigned char)type), event_data::blank);
}
if (type < tls_handshake_type_max) {
// Set the flag this handshake message was received.
m_handshake[type] = true;
}
if (type != tls_handshake_type_hello_request) {
// Hash all but hello requests (https://tools.ietf.org/html/rfc5246#section-7.4.1.1).
hash_handshake(msg, rec_end - msg);
}
msg = rec_end;
}
}
#else
void eap::method_tls::process_handshake()
{
// Prepare input buffer(s).
SecBuffer buf_in[] = {
{
(unsigned long)m_sc_queue.size(),
SECBUFFER_TOKEN,
m_sc_queue.data()
},
{ 0, SECBUFFER_EMPTY, NULL },
};
SecBufferDesc buf_in_desc = { SECBUFFER_VERSION, _countof(buf_in), buf_in };
// Prepare output buffer(s).
SecBuffer buf_out[] = {
{ 0, SECBUFFER_TOKEN, NULL },
{ 0, SECBUFFER_ALERT, NULL },
};
sec_buffer_desc buf_out_desc(buf_out, _countof(buf_out));
SECURITY_STATUS status;
if (m_phase == phase_handshake_init) {
status = m_sc_ctx.initialize(
m_sc_cred,
!m_sc_target_name.empty() ? m_sc_target_name.c_str() : NULL,
ISC_REQ_REPLAY_DETECT | ISC_REQ_SEQUENCE_DETECT | ISC_REQ_CONFIDENTIALITY | ISC_REQ_INTEGRITY | ISC_REQ_STREAM | /*ISC_REQ_USE_SUPPLIED_CREDS |*/ ISC_REQ_EXTENDED_ERROR | ISC_REQ_ALLOCATE_MEMORY,
0,
&buf_in_desc,
&buf_out_desc);
// In a desparate attempt to make Schannel remember and resume the TLS session, we send it the SCHANNEL_SESSION_TOKEN/SSL_SESSION_ENABLE_RECONNECTS
SCHANNEL_SESSION_TOKEN token_session = { SCHANNEL_SESSION, SSL_SESSION_ENABLE_RECONNECTS };
SecBuffer token[] = { { sizeof(token_session), SECBUFFER_TOKEN, &token_session } };
SecBufferDesc token_desc = { SECBUFFER_VERSION, _countof(token), token };
ApplyControlToken(m_sc_ctx, &token_desc);
} else {
status = m_sc_ctx.process(
m_sc_cred,
!m_sc_target_name.empty() ? m_sc_target_name.c_str() : NULL,
ISC_REQ_REPLAY_DETECT | ISC_REQ_SEQUENCE_DETECT | ISC_REQ_CONFIDENTIALITY | ISC_REQ_INTEGRITY | ISC_REQ_STREAM | /*ISC_REQ_USE_SUPPLIED_CREDS |*/ ISC_REQ_EXTENDED_ERROR | ISC_REQ_ALLOCATE_MEMORY,
0,
&buf_in_desc,
&buf_out_desc);
}
#if EAP_TLS < EAP_TLS_SCHANNEL_FULL
if (status == SEC_E_OK)
verify_server_trust();
#endif
if (status == SEC_E_OK || status == SEC_I_CONTINUE_NEEDED) {
// Send Schannel's token via EAP.
assert(buf_out[0].BufferType == SECBUFFER_TOKEN);
assert(m_sc_ctx.m_attrib & ISC_RET_ALLOCATED_MEMORY);
m_packet_res.m_data.assign((const unsigned char*)buf_out[0].pvBuffer, (const unsigned char*)buf_out[0].pvBuffer + buf_out[0].cbBuffer);
if (buf_in[1].BufferType == SECBUFFER_EXTRA) {
// Server appended extra data.
m_sc_queue.erase(m_sc_queue.begin(), m_sc_queue.end() - buf_in[1].cbBuffer);
} else
m_sc_queue.clear();
if (status == SEC_E_OK) {
SecPkgContext_Authority auth;
if (FAILED(status = QueryContextAttributes(m_sc_ctx, SECPKG_ATTR_AUTHORITY, &auth))) {
m_module.log_event(&EAPMETHOD_TLS_QUERY_FAILED, event_data((unsigned int)SECPKG_ATTR_AUTHORITY), event_data(status), event_data::blank);
auth.sAuthorityName = _T("");
}
SecPkgContext_ConnectionInfo info;
if (SUCCEEDED(status = QueryContextAttributes(m_sc_ctx, SECPKG_ATTR_CONNECTION_INFO, &info)))
m_module.log_event(&EAPMETHOD_TLS_HANDSHAKE_FINISHED,
event_data((unsigned int)eap_type_tls),
event_data(auth.sAuthorityName),
event_data(info.dwProtocol),
event_data(info.aiCipher),
event_data(info.dwCipherStrength),
event_data(info.aiHash),
event_data(info.dwHashStrength),
event_data(info.aiExch),
event_data(info.dwExchStrength),
event_data::blank);
else
m_module.log_event(&EAPMETHOD_TLS_QUERY_FAILED, event_data((unsigned int)SECPKG_ATTR_CONNECTION_INFO), event_data(status), event_data::blank);
// Derive challenge for inner authentication (if any).
derive_challenge();
m_phase = phase_application_data;
process_application_data(m_sc_queue.data(), m_sc_queue.size());
} else {
m_phase = phase_handshake_cont;
m_cfg.m_last_status = config_method::status_cred_invalid; // Blame credentials if we fail beyond this point.
}
} else if (status == SEC_E_INCOMPLETE_MESSAGE) {
// Schannel neeeds more data. Send ACK packet to server to send more.
} else if (FAILED(status)) {
if (m_sc_ctx.m_attrib & ISC_RET_EXTENDED_ERROR) {
// Send alert via EAP. Not that EAP will transmit it once we throw this is an error...
assert(buf_out[1].BufferType == SECBUFFER_ALERT);
assert(m_sc_ctx.m_attrib & ISC_RET_ALLOCATED_MEMORY);
m_packet_res.m_data.assign((const unsigned char*)buf_out[1].pvBuffer, (const unsigned char*)buf_out[1].pvBuffer + buf_out[1].cbBuffer);
}
throw sec_runtime_error(status, __FUNCTION__ " Schannel error.");
}
}
void eap::method_tls::process_application_data()
{
if (m_sc_queue.empty()) {
// An ACK packet received. Nothing to unencrypt.
process_application_data(NULL, 0);
return;
}
if (!(m_sc_ctx.m_attrib & ISC_RET_CONFIDENTIALITY))
throw runtime_error(__FUNCTION__ " Connection is not encrypted.");
// Prepare input/output buffer(s).
SecBuffer buf[] = {
{
(unsigned long)m_sc_queue.size(),
SECBUFFER_DATA,
m_sc_queue.data()
},
{ 0, SECBUFFER_EMPTY, NULL },
{ 0, SECBUFFER_EMPTY, NULL },
{ 0, SECBUFFER_EMPTY, NULL },
};
SecBufferDesc buf_desc = {
SECBUFFER_VERSION,
_countof(buf),
buf
};
// Decrypt the message.
SECURITY_STATUS status = DecryptMessage(m_sc_ctx, &buf_desc, 0, NULL);
if (status == SEC_E_OK) {
// Find SECBUFFER_DATA buffer(s) and process data.
for (size_t i = 0; i < _countof(buf); i++)
if (buf[i].BufferType == SECBUFFER_DATA)
process_application_data(buf[i].pvBuffer, buf[i].cbBuffer);
// Find SECBUFFER_EXTRA buffer(s) and queue data for the next time.
std::vector<unsigned char> extra;
for (size_t i = 0; i < _countof(buf); i++)
if (buf[i].BufferType == SECBUFFER_EXTRA)
extra.insert(extra.end(), (unsigned char*)buf[i].pvBuffer, (unsigned char*)buf[i].pvBuffer + buf[i].cbBuffer);
m_sc_queue = std::move(extra);
} else if (status == SEC_E_INCOMPLETE_MESSAGE) {
// Schannel neeeds more data. Send ACK packet to server to send more.
} else if (status == SEC_I_CONTEXT_EXPIRED) {
// Server initiated connection shutdown.
m_sc_queue.clear();
m_phase = phase_shutdown;
} else if (status == SEC_I_RENEGOTIATE) {
// Re-negotiation required.
m_sc_queue.clear();
m_phase = phase_handshake_init;
process_handshake();
} else if (FAILED(status))
throw sec_runtime_error(status, __FUNCTION__ " Schannel error.");
}
#endif
void eap::method_tls::process_application_data(_In_bytecount_(size_msg) const void *msg, _In_ size_t size_msg)
{
UNREFERENCED_PARAMETER(msg);
UNREFERENCED_PARAMETER(size_msg);
}
#if EAP_TLS < EAP_TLS_SCHANNEL_FULL
void eap::method_tls::verify_server_trust() const
{
#if EAP_TLS < EAP_TLS_SCHANNEL
assert(!m_server_cert_chain.empty());
const cert_context &cert = m_server_cert_chain.front();
#else
cert_context cert;
SECURITY_STATUS status = QueryContextAttributes(m_sc_ctx, SECPKG_ATTR_REMOTE_CERT_CONTEXT, (PVOID)&cert);
if (FAILED(status))
throw sec_runtime_error(status, __FUNCTION__ " Error retrieving server certificate from Schannel.");
#endif
for (list<cert_context>::const_iterator c = m_cfg.m_trusted_root_ca.cbegin(), c_end = m_cfg.m_trusted_root_ca.cend(); c != c_end; ++c) {
if (cert->cbCertEncoded == (*c)->cbCertEncoded &&
memcmp(cert->pbCertEncoded, (*c)->pbCertEncoded, cert->cbCertEncoded) == 0)
{
// Server certificate found directly on the trusted root CA list.
m_module.log_event(&EAPMETHOD_TLS_SERVER_CERT_TRUSTED_EX, event_data::blank);
return;
}
}
// Check server name.
if (!m_cfg.m_server_names.empty()) {
bool
has_san = false,
found = false;
// Search subjectAltName2 and subjectAltName.
for (DWORD idx_ext = 0; !found && idx_ext < cert->pCertInfo->cExtension; idx_ext++) {
unique_ptr<CERT_ALT_NAME_INFO, LocalFree_delete<CERT_ALT_NAME_INFO> > san_info;
if (strcmp(cert->pCertInfo->rgExtension[idx_ext].pszObjId, szOID_SUBJECT_ALT_NAME2) == 0) {
unsigned char *output = NULL;
DWORD size_output;
if (!CryptDecodeObjectEx(
X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
szOID_SUBJECT_ALT_NAME2,
cert->pCertInfo->rgExtension[idx_ext].Value.pbData, cert->pCertInfo->rgExtension[idx_ext].Value.cbData,
CRYPT_DECODE_ALLOC_FLAG | CRYPT_DECODE_ENABLE_PUNYCODE_FLAG,
NULL,
&output, &size_output))
throw win_runtime_error(__FUNCTION__ " Error decoding subjectAltName2 certificate extension.");
san_info.reset((CERT_ALT_NAME_INFO*)output);
} else if (strcmp(cert->pCertInfo->rgExtension[idx_ext].pszObjId, szOID_SUBJECT_ALT_NAME) == 0) {
unsigned char *output = NULL;
DWORD size_output;
if (!CryptDecodeObjectEx(
X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
szOID_SUBJECT_ALT_NAME,
cert->pCertInfo->rgExtension[idx_ext].Value.pbData, cert->pCertInfo->rgExtension[idx_ext].Value.cbData,
CRYPT_DECODE_ALLOC_FLAG | CRYPT_DECODE_ENABLE_PUNYCODE_FLAG,
NULL,
&output, &size_output))
throw win_runtime_error(__FUNCTION__ " Error decoding subjectAltName certificate extension.");
san_info.reset((CERT_ALT_NAME_INFO*)output);
} else {
// Skip this extension.
continue;
}
has_san = true;
for (list<wstring>::const_iterator s = m_cfg.m_server_names.cbegin(), s_end = m_cfg.m_server_names.cend(); !found && s != s_end; ++s) {
for (DWORD idx_entry = 0; !found && idx_entry < san_info->cAltEntry; idx_entry++) {
if (san_info->rgAltEntry[idx_entry].dwAltNameChoice == CERT_ALT_NAME_DNS_NAME &&
_wcsicmp(s->c_str(), san_info->rgAltEntry[idx_entry].pwszDNSName) == 0)
{
m_module.log_event(&EAPMETHOD_TLS_SERVER_NAME_TRUSTED1, event_data(san_info->rgAltEntry[idx_entry].pwszDNSName), event_data::blank);
found = true;
}
}
}
}
if (!has_san) {
// Certificate has no subjectAltName. Compare against Common Name.
wstring subj;
if (!CertGetNameStringW(cert, CERT_NAME_DNS_TYPE, CERT_NAME_STR_ENABLE_PUNYCODE_FLAG, NULL, subj))
throw win_runtime_error(__FUNCTION__ " Error retrieving server's certificate subject name.");
for (list<wstring>::const_iterator s = m_cfg.m_server_names.cbegin(), s_end = m_cfg.m_server_names.cend(); !found && s != s_end; ++s) {
if (_wcsicmp(s->c_str(), subj.c_str()) == 0) {
m_module.log_event(&EAPMETHOD_TLS_SERVER_NAME_TRUSTED1, event_data(subj), event_data::blank);
found = true;
}
}
}
if (!found)
throw sec_runtime_error(SEC_E_WRONG_PRINCIPAL, __FUNCTION__ " Name provided in server certificate is not on the list of trusted server names.");
}
if (cert->pCertInfo->Issuer.cbData == cert->pCertInfo->Subject.cbData &&
memcmp(cert->pCertInfo->Issuer.pbData, cert->pCertInfo->Subject.pbData, cert->pCertInfo->Issuer.cbData) == 0)
throw sec_runtime_error(SEC_E_CERT_UNKNOWN, __FUNCTION__ " Server is using a self-signed certificate. Cannot trust it.");
// Create temporary certificate store of our trusted root CAs.
cert_store store;
if (!store.create(CERT_STORE_PROV_MEMORY, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, NULL, 0, NULL))
throw win_runtime_error(__FUNCTION__ " Error creating temporary certificate store.");
for (list<cert_context>::const_iterator c = m_cfg.m_trusted_root_ca.cbegin(), c_end = m_cfg.m_trusted_root_ca.cend(); c != c_end; ++c)
CertAddCertificateContextToStore(store, *c, CERT_STORE_ADD_REPLACE_EXISTING, NULL);
// Add all intermediate certificates from the server's certificate chain.
#if EAP_TLS < EAP_TLS_SCHANNEL
for (list<cert_context>::const_iterator c = m_server_cert_chain.cbegin(), c_end = m_server_cert_chain.cend(); ++c != c_end;) {
const cert_context &_c = *c;
if (_c->pCertInfo->Issuer.cbData == _c->pCertInfo->Subject.cbData &&
memcmp(_c->pCertInfo->Issuer.pbData, _c->pCertInfo->Subject.pbData, _c->pCertInfo->Issuer.cbData) == 0)
{
// Skip the root CA certificates (self-signed). We define in whom we trust!
continue;
}
CertAddCertificateContextToStore(store, *c, CERT_STORE_ADD_REPLACE_EXISTING, NULL);
}
#else
for (cert_context c(cert); c;) {
DWORD flags = 0;
c.attach(CertGetIssuerCertificateFromStore(cert->hCertStore, c, NULL, &flags));
if (!c) break;
if (c->pCertInfo->Issuer.cbData == c->pCertInfo->Subject.cbData &&
memcmp(c->pCertInfo->Issuer.pbData, c->pCertInfo->Subject.pbData, c->pCertInfo->Issuer.cbData) == 0)
{
// Skip the root CA certificates (self-signed). We define in whom we trust!
continue;
}
CertAddCertificateContextToStore(store, c, CERT_STORE_ADD_REPLACE_EXISTING, NULL);
}
#endif
// Prepare the certificate chain validation, and check.
CERT_CHAIN_PARA chain_params = {
sizeof(chain_params), // cbSize
{
USAGE_MATCH_TYPE_AND, // RequestedUsage.dwType
{}, // RequestedUsage.Usage
},
#ifdef CERT_CHAIN_PARA_HAS_EXTRA_FIELDS
{}, // RequestedIssuancePolicy
1, // dwUrlRetrievalTimeout (1ms to speed up checking)
#else
#define _S2(x) #x
#define _S(x) _S2(x)
#pragma message(__FILE__ "(" _S(__LINE__) "): warning X0000: Please define CERT_CHAIN_PARA_HAS_EXTRA_FIELDS constant when compiling this project.")
#endif
};
cert_chain_context context;
if (!context.create(NULL, cert, NULL, store, &chain_params, 0))
throw win_runtime_error(__FUNCTION__ " Error creating certificate chain context.");
// Check chain validation error flags. Ignore CERT_TRUST_IS_UNTRUSTED_ROOT flag since we check root CA explicitly.
if (context->TrustStatus.dwErrorStatus != CERT_TRUST_NO_ERROR &&
(context->TrustStatus.dwErrorStatus & ~CERT_TRUST_IS_UNTRUSTED_ROOT) != CERT_TRUST_NO_ERROR)
{
if (context->TrustStatus.dwErrorStatus & (CERT_TRUST_IS_NOT_TIME_VALID | CERT_TRUST_IS_NOT_TIME_NESTED))
throw sec_runtime_error(SEC_E_CERT_EXPIRED, __FUNCTION__ " Server certificate has expired (or is not valid yet).");
else if (context->TrustStatus.dwErrorStatus & (CERT_TRUST_IS_UNTRUSTED_ROOT | CERT_TRUST_IS_PARTIAL_CHAIN))
throw sec_runtime_error(SEC_E_UNTRUSTED_ROOT, __FUNCTION__ " Server's certificate not issued by one of configured trusted root CAs.");
else
throw sec_runtime_error(SEC_E_CERT_UNKNOWN, __FUNCTION__ " Error validating server certificate.");
}
// Verify Root CA against our trusted root CA list
if (context->cChain != 1)
throw sec_runtime_error(SEC_E_CERT_UNKNOWN, __FUNCTION__ " Multiple chain verification not supported.");
if (context->rgpChain[0]->cElement == 0)
throw sec_runtime_error(SEC_E_CERT_UNKNOWN, __FUNCTION__ " Can not verify empty certificate chain.");
PCCERT_CONTEXT cert_root = context->rgpChain[0]->rgpElement[context->rgpChain[0]->cElement-1]->pCertContext;
for (list<cert_context>::const_iterator c = m_cfg.m_trusted_root_ca.cbegin(), c_end = m_cfg.m_trusted_root_ca.cend();; ++c) {
if (c != c_end) {
if (cert_root->cbCertEncoded == (*c)->cbCertEncoded &&
memcmp(cert_root->pbCertEncoded, (*c)->pbCertEncoded, cert_root->cbCertEncoded) == 0)
{
// Trusted root CA found.
break;
}
} else {
// Not found.
throw sec_runtime_error(SEC_E_UNTRUSTED_ROOT, __FUNCTION__ " Server's certificate not issued by one of configured trusted root CAs.");
}
}
m_module.log_event(&EAPMETHOD_TLS_SERVER_CERT_TRUSTED, event_data::blank);
}
#endif
#if EAP_TLS < EAP_TLS_SCHANNEL
void eap::method_tls::encrypt_message(_In_ tls_message_type_t type, _Inout_ sanitizing_blob &data)
{
// Hash sequence number, TLS header, and message.
size_t size_data = data.size();
hmac_hash hash(m_cp, m_state_client.m_alg_mac, m_state_client.m_padding_hmac);
unsigned __int64 seq_num2 = htonll(m_seq_num_client);
unsigned short size_data2 = htons((unsigned short)size_data);
if (!CryptHashData(hash, (const BYTE*)&seq_num2 , sizeof(seq_num2 ), 0) ||
!CryptHashData(hash, (const BYTE*)&type , sizeof(type ), 0) ||
!CryptHashData(hash, (const BYTE*)&m_tls_version, sizeof(m_tls_version), 0) ||
!CryptHashData(hash, (const BYTE*)&size_data2 , sizeof(size_data2 ), 0) ||
!CryptHashData(hash, data.data() , (DWORD)size_data , 0))
throw win_runtime_error(__FUNCTION__ " Error hashing data.");
sanitizing_blob hmac;
hash.calculate(hmac);
size_t size_data_enc =
size_data + // TLS message
hmac.size(); // HMAC hash
if (m_state_client.m_size_enc_block) {
// Block cypher
if (m_tls_version >= tls_version_1_1) {
// TLS 1.1+: Set random IV.
data.insert(data.begin(), m_state_client.m_size_enc_iv, 0);
if (!CryptGenRandom(m_cp, (DWORD)m_state_client.m_size_enc_iv, data.data()))
throw win_runtime_error(__FUNCTION__ " Error generating IV.");
size_data_enc += m_state_client.m_size_enc_iv;
}
// Calculate padding.
size_data_enc += 1; // Padding length
unsigned char size_padding = (unsigned char)((m_state_client.m_size_enc_block - size_data_enc) % m_state_client.m_size_enc_block);
size_data_enc += size_padding;
// Append HMAC hash and padding.
data.reserve(size_data_enc);
data.insert(data.end(), hmac.begin(), hmac.end());
data.insert(data.end(), size_padding + 1, size_padding);
} else {
// Stream cipher
// Append HMAC hash.
data.reserve(size_data_enc);
data.insert(data.end(), hmac.begin(), hmac.end());
}
// Encrypt.
assert(size_data_enc < 0xffffffff);
DWORD size_data_enc2 = (DWORD)size_data_enc;
if (!CryptEncrypt(m_state_client.m_key, NULL, FALSE, 0, data.data(), &size_data_enc2, (DWORD)size_data_enc))
throw win_runtime_error(__FUNCTION__ " Error encrypting message.");
// Increment sequence number.
m_seq_num_client++;
}
void eap::method_tls::decrypt_message(_In_ tls_message_type_t type, _Inout_ sanitizing_blob &data)
{
// Decrypt.
if (!CryptDecrypt(m_state_server.m_key, NULL, FALSE, 0, data))
throw win_runtime_error(__FUNCTION__ " Error decrypting message.");
if (!data.empty()) {
size_t size_data = data.size();
bool padding_ok = true;
if (m_state_server.m_size_enc_block) {
// Check padding. Do not throw until HMAC is calculated.
// [Canvel, B., "Password Interception in a SSL/TLS Channel"](http://lasecwww.epfl.ch/memo_ssl.shtml)
unsigned char padding = data.back();
size_data = (size_t)padding + 1 <= size_data ? size_data - (padding + 1) : 0;
for (size_t i = size_data, i_end = data.size() - 1; i < i_end; i++)
if (data[i] != padding)
padding_ok = false;
// Remove padding.
data.resize(size_data);
if (m_tls_version >= tls_version_1_1) {
// TLS 1.1+: Remove random IV.
data.erase(data.begin(), data.begin() + m_state_server.m_size_enc_iv);
size_data -= m_state_server.m_size_enc_iv;
}
}
size_data -= m_state_server.m_size_mac_hash;
// Hash sequence number, TLS header (without length), original message length, and message.
hmac_hash hash(m_cp, m_state_server.m_alg_mac, m_state_server.m_padding_hmac);
unsigned __int64 seq_num2 = htonll(m_seq_num_server);
unsigned short size_data2 = htons((unsigned short)size_data);
if (!CryptHashData(hash, (const BYTE*)&seq_num2 , sizeof(seq_num2 ), 0) ||
!CryptHashData(hash, (const BYTE*)&type , sizeof(type ), 0) ||
!CryptHashData(hash, (const BYTE*)&m_tls_version, sizeof(m_tls_version), 0) ||
!CryptHashData(hash, (const BYTE*)&size_data2 , sizeof(size_data2 ), 0) ||
!CryptHashData(hash, data.data() , (DWORD)size_data , 0))
throw win_runtime_error(__FUNCTION__ " Error hashing data.");
sanitizing_blob hmac;
hash.calculate(hmac);
// // Check padding results.
if (!padding_ok)
throw invalid_argument(__FUNCTION__ " Incorrect message padding.");
// Verify hash.
if (memcmp(&*(data.begin() + size_data), hmac.data(), m_state_server.m_size_mac_hash) != 0)
throw win_runtime_error(ERROR_DECRYPTION_FAILED, __FUNCTION__ " Integrity check failed.");
// Strip hash and padding.
data.resize(size_data);
// Increment sequence number.
m_seq_num_server++;
}
}
size_t eap::method_tls::get_max_message(_In_ size_t size_message) const
{
if (m_state_client.m_size_enc_block) {
// Padding
size_message -= size_message % m_state_client.m_size_enc_block;
size_message--;
// HMAC
size_message -= m_state_client.m_size_mac_hash;
if (m_tls_version >= tls_version_1_1) {
// IV (TLS 1.1+)
size_message -= m_state_client.m_size_enc_iv;
}
} else {
// HMAC
size_message -= m_state_client.m_size_mac_hash;
}
return size_message;
}
eap::sanitizing_blob eap::method_tls::prf(
_In_ HCRYPTPROV cp,
_In_ ALG_ID alg,
_In_ const tls_master_secret &secret,
_In_bytecount_(size_seed) const void *seed,
_In_ size_t size_seed,
_In_ size_t size)
{
sanitizing_blob data;
data.reserve(size);
if (alg == CALG_TLS1PRF) {
// Split secret in two halves.
size_t
size_S1 = (sizeof(tls_master_secret) + 1) / 2,
size_S2 = size_S1;
const void
*S1 = &secret,
*S2 = (const unsigned char*)&secret + (sizeof(tls_master_secret) - size_S2);
// Precalculate HMAC padding for speed.
hmac_padding
padding1(cp, CALG_MD5 , S1, size_S1),
padding2(cp, CALG_SHA1, S2, size_S2);
// Prepare A for p_hash.
sanitizing_blob
A1((unsigned char*)seed, (unsigned char*)seed + size_seed),
A2((unsigned char*)seed, (unsigned char*)seed + size_seed);
sanitizing_blob
hmac1,
hmac2;
data.resize(size);
for (size_t i = 0, off1 = 0, off2 = 0; i < size; ) {
if (off1 >= hmac1.size()) {
// Rehash A.
hmac_hash hash1(cp, CALG_MD5 , padding1);
if (!CryptHashData(hash1, A1.data(), (DWORD)A1.size(), 0))
throw win_runtime_error(__FUNCTION__ " Error hashing A1.");
hash1.calculate(A1);
// Hash A and seed.
hmac_hash hash2(cp, CALG_MD5 , padding1);
if (!CryptHashData(hash2, A1.data(), (DWORD)A1.size(), 0) ||
!CryptHashData(hash2, (const BYTE*)seed , (DWORD)size_seed, 0))
throw win_runtime_error(__FUNCTION__ " Error hashing seed,label or data.");
hash2.calculate(hmac1);
off1 = 0;
}
if (off2 >= hmac2.size()) {
// Rehash A.
hmac_hash hash1(cp, CALG_SHA1 , padding2);
if (!CryptHashData(hash1, A2.data(), (DWORD)A2.size(), 0))
throw win_runtime_error(__FUNCTION__ " Error hashing A2.");
hash1.calculate(A2);
// Hash A and seed.
hmac_hash hash2(cp, CALG_SHA1 , padding2);
if (!CryptHashData(hash2, A2.data(), (DWORD)A2.size(), 0) ||
!CryptHashData(hash2, (const BYTE*)seed , (DWORD)size_seed, 0))
throw win_runtime_error(__FUNCTION__ " Error hashing seed,label or data.");
hash2.calculate(hmac2);
off2 = 0;
}
// XOR combine amount of data we have (and need).
size_t i_end = std::min<size_t>(i + std::min<size_t>(hmac1.size() - off1, hmac2.size() - off2), size);
while (i < i_end)
data[i++] = hmac1[off1++] ^ hmac2[off2++];
}
} else {
// Precalculate HMAC padding for speed.
hmac_padding padding(cp, alg, &secret, sizeof(tls_master_secret));
// Prepare A for p_hash.
sanitizing_blob A((unsigned char*)seed, (unsigned char*)seed + size_seed);
sanitizing_blob hmac;
for (size_t i = 0; i < size; ) {
// Rehash A.
hmac_hash hash1(cp, alg, padding);
if (!CryptHashData(hash1, A.data(), (DWORD)A.size(), 0))
throw win_runtime_error(__FUNCTION__ " Error hashing A.");
hash1.calculate(A);
// Hash A and seed.
hmac_hash hash2(cp, alg, padding);
if (!CryptHashData(hash2, A.data(), (DWORD)A.size() , 0) ||
!CryptHashData(hash2, (const BYTE*)seed , (DWORD)size_seed, 0))
throw win_runtime_error(__FUNCTION__ " Error hashing seed,label or data.");
hash2.calculate(hmac);
size_t n = std::min<size_t>(hmac.size(), size - i);
data.insert(data.end(), hmac.begin(), hmac.begin() + n);
i += n;
}
}
return data;
}
HCRYPTKEY eap::method_tls::create_key(
_In_ HCRYPTPROV cp,
_In_ ALG_ID alg,
_In_ HCRYPTKEY key,
_In_bytecount_(size_secret) const void *secret,
_In_ size_t size_secret)
{
#if 1
UNREFERENCED_PARAMETER(key);
assert(size_secret <= 0xffffffff);
// Prepare exported key BLOB.
struct key_blob_prefix {
PUBLICKEYSTRUC header;
DWORD size;
} const prefix = {
{
PLAINTEXTKEYBLOB,
CUR_BLOB_VERSION,
0,
alg,
},
(DWORD)size_secret,
};
sanitizing_blob key_blob;
key_blob.reserve(sizeof(key_blob_prefix) + size_secret);
key_blob.assign((const unsigned char*)&prefix, (const unsigned char*)(&prefix + 1));
key_blob.insert(key_blob.end(), (const unsigned char*)secret, (const unsigned char*)secret + size_secret);
// Import the key.
winstd::crypt_key key_out;
if (!key_out.import(cp, key_blob.data(), (DWORD)key_blob.size(), NULL, 0))
throw winstd::win_runtime_error(__FUNCTION__ " Error importing key.");
return key_out.detach();
#else
// Get private key's algorithm.
ALG_ID alg_key;
if (!CryptGetKeyParam(key, KP_ALGID, alg_key, 0))
throw win_runtime_error(__FUNCTION__ " Error getting key's algorithm.'");
// Get private key's length in bytes.
DWORD size_key = CryptGetKeyParam(key, KP_KEYLEN, size_key, 0) ? size_key/8 : 0;
// SIMPLEBLOB Format is documented in SDK
// Copy header to buffer
#pragma pack(push)
#pragma pack(1)
struct key_blob_prefix {
PUBLICKEYSTRUC header;
ALG_ID alg;
} const prefix = {
{
SIMPLEBLOB,
CUR_BLOB_VERSION,
0,
alg,
},
alg_key,
};
#pragma pack(pop)
sanitizing_blob key_blob;
key_blob.reserve(sizeof(key_blob_prefix) + size_key);
key_blob.assign((const unsigned char*)&prefix, (const unsigned char*)(&prefix + 1));
// Key in EME-PKCS1-v1_5 (RFC 3447).
key_blob.push_back(0); // Initial zero
key_blob.push_back(2); // PKCS #1 block type = 2
// PS
size_t size_ps = size_key - size_secret - 3;
assert(size_ps >= 8);
#if 1
key_blob.insert(key_blob.end(), size_ps, 1);
#else
// Is random PS required at all? We are importing a clear-text session key with the exponent-of-one key. How low on security can we get?
key_blob.insert(key_blob.end(), size_ps, 0);
unsigned char *ps = &*(key_blob.end() - size_ps);
CryptGenRandom(cp, (DWORD)size_ps, ps);
for (size_t i = 0; i < size_ps; i++)
if (ps[i] == 0) ps[i] = 1;
#endif
key_blob.push_back(0); // PS and M zero delimiter
// M
key_blob.insert(key_blob.end(), (const unsigned char*)secret, (const unsigned char*)secret + size_secret);
#ifdef _HOST_LOW_ENDIAN
std::reverse(key_blob.end() - size_key, key_blob.end());
#endif
// Import the key.
winstd::crypt_key key_out;
if (!key_out.import(cp, key_blob.data(), (DWORD)key_blob.size(), key, 0))
throw winstd::win_runtime_error(__FUNCTION__ " Error importing key.");
return key_out.detach();
#endif
}
#endif