2 * Copyright (c) 2007, Cameron Rich
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
9 * * Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 * * Neither the name of the axTLS project nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
22 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
23 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
24 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
25 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
26 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
27 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 #ifdef CONFIG_SSL_ENABLE_CLIENT /* all commented out if no client */
40 static int send_client_hello(SSL *ssl);
41 static int process_server_hello(SSL *ssl);
42 static int process_server_hello_done(SSL *ssl);
43 static int send_client_key_xchg(SSL *ssl);
44 static int process_cert_req(SSL *ssl);
45 static int send_cert_verify(SSL *ssl);
48 * Establish a new SSL connection to an SSL server.
50 EXP_FUNC SSL * STDCALL ssl_client_new(SSL_CTX *ssl_ctx, int client_fd, const
51 uint8_t *session_id, uint8_t sess_id_size)
56 SOCKET_BLOCK(client_fd); /* ensure blocking mode */
57 ssl = ssl_new(ssl_ctx, client_fd);
59 if (session_id && ssl_ctx->num_sessions)
61 if (sess_id_size > SSL_SESSION_ID_SIZE) /* validity check */
67 memcpy(ssl->session_id, session_id, sess_id_size);
68 ssl->sess_id_size = sess_id_size;
69 SET_SSL_FLAG(SSL_SESSION_RESUME); /* just flag for later */
72 SET_SSL_FLAG(SSL_IS_CLIENT);
73 ret = do_client_connect(ssl);
78 * Process the handshake record.
80 int do_clnt_handshake(SSL *ssl, int handshake_type, uint8_t *buf, int hs_len)
84 /* To get here the state must be valid */
85 switch (handshake_type)
88 ret = process_server_hello(ssl);
92 ret = process_certificate(ssl, &ssl->x509_ctx);
95 case HS_SERVER_HELLO_DONE:
96 if ((ret = process_server_hello_done(ssl)) == SSL_OK)
98 if (IS_SET_SSL_FLAG(SSL_HAS_CERT_REQ))
100 if ((ret = send_certificate(ssl)) == SSL_OK &&
101 (ret = send_client_key_xchg(ssl)) == SSL_OK)
103 send_cert_verify(ssl);
108 ret = send_client_key_xchg(ssl);
112 (ret = send_change_cipher_spec(ssl)) == SSL_OK)
114 ret = send_finished(ssl);
120 ret = process_cert_req(ssl);
124 ret = process_finished(ssl, hs_len);
125 disposable_free(ssl); /* free up some memory */
128 case HS_HELLO_REQUEST:
130 ret = do_client_connect(ssl);
138 * Do the handshaking from the beginning.
140 int do_client_connect(SSL *ssl)
144 send_client_hello(ssl); /* send the client hello */
145 ssl->bm_read_index = 0;
146 ssl->next_state = HS_SERVER_HELLO;
147 ssl->hs_status = SSL_NOT_OK; /* not connected */
148 x509_free(ssl->x509_ctx);
150 /* sit in a loop until it all looks good */
151 while (ssl->hs_status != SSL_OK)
153 ret = basic_read(ssl, NULL);
157 if (ret != SSL_ERROR_CONN_LOST)
159 /* let the server know we are dying and why */
160 if (send_alert(ssl, ret))
162 /* something nasty happened, so get rid of it */
163 kill_ssl_session(ssl->ssl_ctx->ssl_sessions, ssl);
171 ssl->hs_status = ret; /* connected? */
176 * Send the initial client hello.
178 static int send_client_hello(SSL *ssl)
180 uint8_t *buf = ssl->bm_data;
181 time_t tm = time(NULL);
182 uint8_t *tm_ptr = &buf[6]; /* time will go here */
185 buf[0] = HS_CLIENT_HELLO;
188 /* byte 3 is calculated later */
192 /* client random value - spec says that 1st 4 bytes are big endian time */
193 *tm_ptr++ = (uint8_t)(((long)tm & 0xff000000) >> 24);
194 *tm_ptr++ = (uint8_t)(((long)tm & 0x00ff0000) >> 16);
195 *tm_ptr++ = (uint8_t)(((long)tm & 0x0000ff00) >> 8);
196 *tm_ptr++ = (uint8_t)(((long)tm & 0x000000ff));
197 get_random(SSL_RANDOM_SIZE-4, &buf[10]);
198 memcpy(ssl->dc->client_random, &buf[6], SSL_RANDOM_SIZE);
199 offset = 6 + SSL_RANDOM_SIZE;
201 /* give session resumption a go */
202 if (IS_SET_SSL_FLAG(SSL_SESSION_RESUME)) /* set initially by user */
204 buf[offset++] = ssl->sess_id_size;
205 memcpy(&buf[offset], ssl->session_id, ssl->sess_id_size);
206 offset += ssl->sess_id_size;
207 CLR_SSL_FLAG(SSL_SESSION_RESUME); /* clear so we can set later */
211 /* no session id - because no session resumption just yet */
215 buf[offset++] = 0; /* number of ciphers */
216 buf[offset++] = NUM_PROTOCOLS*2;/* number of ciphers */
218 /* put all our supported protocols in our request */
219 for (i = 0; i < NUM_PROTOCOLS; i++)
221 buf[offset++] = 0; /* cipher we are using */
222 buf[offset++] = ssl_prot_prefs[i];
225 buf[offset++] = 1; /* no compression */
227 buf[3] = offset - 4; /* handshake size */
229 return send_packet(ssl, PT_HANDSHAKE_PROTOCOL, NULL, offset);
233 * Process the server hello.
235 static int process_server_hello(SSL *ssl)
237 uint8_t *buf = ssl->bm_data;
238 int pkt_size = ssl->bm_index;
239 int version = (buf[4] << 4) + buf[5];
240 int num_sessions = ssl->ssl_ctx->num_sessions;
241 uint8_t sess_id_size;
242 int offset, ret = SSL_OK;
244 /* check that we are talking to a TLSv1 server */
246 return SSL_ERROR_INVALID_VERSION;
248 /* get the server random value */
249 memcpy(ssl->dc->server_random, &buf[6], SSL_RANDOM_SIZE);
250 offset = 6 + SSL_RANDOM_SIZE; /* skip of session id size */
251 sess_id_size = buf[offset++];
255 ssl->session = ssl_session_update(num_sessions,
256 ssl->ssl_ctx->ssl_sessions, ssl, &buf[offset]);
257 memcpy(ssl->session->session_id, &buf[offset], sess_id_size);
259 /* pad the rest with 0's */
260 if (sess_id_size < SSL_SESSION_ID_SIZE)
262 memset(&ssl->session->session_id[sess_id_size], 0,
263 SSL_SESSION_ID_SIZE-sess_id_size);
267 memcpy(ssl->session_id, &buf[offset], sess_id_size);
268 ssl->sess_id_size = sess_id_size;
269 offset += sess_id_size;
271 /* get the real cipher we are using */
272 ssl->cipher = buf[++offset];
273 ssl->next_state = IS_SET_SSL_FLAG(SSL_SESSION_RESUME) ?
274 HS_FINISHED : HS_CERTIFICATE;
276 offset++; // skip the compr
277 PARANOIA_CHECK(pkt_size, offset);
278 ssl->dc->bm_proc_index = offset+1;
285 * Process the server hello done message.
287 static int process_server_hello_done(SSL *ssl)
289 ssl->next_state = HS_FINISHED;
294 * Send a client key exchange message.
296 static int send_client_key_xchg(SSL *ssl)
298 uint8_t *buf = ssl->bm_data;
299 uint8_t premaster_secret[SSL_SECRET_SIZE];
300 int enc_secret_size = -1;
302 buf[0] = HS_CLIENT_KEY_XCHG;
305 premaster_secret[0] = 0x03; /* encode the version number */
306 premaster_secret[1] = 0x01;
307 get_random(SSL_SECRET_SIZE-2, &premaster_secret[2]);
308 DISPLAY_RSA(ssl, ssl->x509_ctx->rsa_ctx);
310 /* rsa_ctx->bi_ctx is not thread-safe */
311 SSL_CTX_LOCK(ssl->ssl_ctx->mutex);
312 enc_secret_size = RSA_encrypt(ssl->x509_ctx->rsa_ctx, premaster_secret,
313 SSL_SECRET_SIZE, &buf[6], 0);
314 SSL_CTX_UNLOCK(ssl->ssl_ctx->mutex);
316 buf[2] = (enc_secret_size + 2) >> 8;
317 buf[3] = (enc_secret_size + 2) & 0xff;
318 buf[4] = enc_secret_size >> 8;
319 buf[5] = enc_secret_size & 0xff;
321 generate_master_secret(ssl, premaster_secret);
322 return send_packet(ssl, PT_HANDSHAKE_PROTOCOL, NULL, enc_secret_size+6);
326 * Process the certificate request.
328 static int process_cert_req(SSL *ssl)
330 uint8_t *buf = &ssl->bm_data[ssl->dc->bm_proc_index];
332 int offset = (buf[2] << 4) + buf[3];
333 int pkt_size = ssl->bm_index;
335 /* don't do any processing - we will send back an RSA certificate anyway */
336 ssl->next_state = HS_SERVER_HELLO_DONE;
337 SET_SSL_FLAG(SSL_HAS_CERT_REQ);
338 ssl->dc->bm_proc_index += offset;
339 PARANOIA_CHECK(pkt_size, offset);
345 * Send a certificate verify message.
347 static int send_cert_verify(SSL *ssl)
349 uint8_t *buf = ssl->bm_data;
350 uint8_t dgst[MD5_SIZE+SHA1_SIZE];
351 RSA_CTX *rsa_ctx = ssl->ssl_ctx->rsa_ctx;
354 DISPLAY_RSA(ssl, rsa_ctx);
356 buf[0] = HS_CERT_VERIFY;
359 finished_digest(ssl, NULL, dgst); /* calculate the digest */
361 /* rsa_ctx->bi_ctx is not thread-safe */
364 SSL_CTX_LOCK(ssl->ssl_ctx->mutex);
365 n = RSA_encrypt(rsa_ctx, dgst, sizeof(dgst), &buf[6], 1);
366 SSL_CTX_UNLOCK(ssl->ssl_ctx->mutex);
370 ret = SSL_ERROR_INVALID_KEY;
375 buf[4] = n >> 8; /* add the RSA size (not officially documented) */
380 ret = send_packet(ssl, PT_HANDSHAKE_PROTOCOL, NULL, n+4);
386 #endif /* CONFIG_SSL_ENABLE_CLIENT */