1 /*
2 * SSL client demonstration program
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19
20 #include "mbedtls/build_info.h"
21
22 #include "mbedtls/platform.h"
23
24 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_ENTROPY_C) || \
25 !defined(MBEDTLS_SSL_TLS_C) || !defined(MBEDTLS_SSL_CLI_C) || \
26 !defined(MBEDTLS_NET_C) || !defined(MBEDTLS_RSA_C) || \
27 !defined(MBEDTLS_PEM_PARSE_C) || !defined(MBEDTLS_CTR_DRBG_C) || \
28 !defined(MBEDTLS_X509_CRT_PARSE_C)
main(void)29 int main(void)
30 {
31 mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_ENTROPY_C and/or "
32 "MBEDTLS_SSL_TLS_C and/or MBEDTLS_SSL_CLI_C and/or "
33 "MBEDTLS_NET_C and/or MBEDTLS_RSA_C and/or "
34 "MBEDTLS_CTR_DRBG_C and/or MBEDTLS_X509_CRT_PARSE_C "
35 "not defined.\n");
36 mbedtls_exit(0);
37 }
38 #else
39
40 #include "mbedtls/net_sockets.h"
41 #include "mbedtls/debug.h"
42 #include "mbedtls/ssl.h"
43 #include "mbedtls/entropy.h"
44 #include "mbedtls/ctr_drbg.h"
45 #include "mbedtls/error.h"
46 #include "test/certs.h"
47
48 #include <string.h>
49
50 #define SERVER_PORT "4433"
51 #define SERVER_NAME "localhost"
52 #define GET_REQUEST "GET / HTTP/1.0\r\n\r\n"
53
54 #define DEBUG_LEVEL 1
55
56
my_debug(void * ctx,int level,const char * file,int line,const char * str)57 static void my_debug(void *ctx, int level,
58 const char *file, int line,
59 const char *str)
60 {
61 ((void) level);
62
63 mbedtls_fprintf((FILE *) ctx, "%s:%04d: %s", file, line, str);
64 fflush((FILE *) ctx);
65 }
66
main(void)67 int main(void)
68 {
69 int ret = 1, len;
70 int exit_code = MBEDTLS_EXIT_FAILURE;
71 mbedtls_net_context server_fd;
72 uint32_t flags;
73 unsigned char buf[1024];
74 const char *pers = "ssl_client1";
75
76 mbedtls_entropy_context entropy;
77 mbedtls_ctr_drbg_context ctr_drbg;
78 mbedtls_ssl_context ssl;
79 mbedtls_ssl_config conf;
80 mbedtls_x509_crt cacert;
81
82 #if defined(MBEDTLS_DEBUG_C)
83 mbedtls_debug_set_threshold(DEBUG_LEVEL);
84 #endif
85
86 /*
87 * 0. Initialize the RNG and the session data
88 */
89 mbedtls_net_init(&server_fd);
90 mbedtls_ssl_init(&ssl);
91 mbedtls_ssl_config_init(&conf);
92 mbedtls_x509_crt_init(&cacert);
93 mbedtls_ctr_drbg_init(&ctr_drbg);
94
95 mbedtls_printf("\n . Seeding the random number generator...");
96 fflush(stdout);
97
98 mbedtls_entropy_init(&entropy);
99 if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy,
100 (const unsigned char *) pers,
101 strlen(pers))) != 0) {
102 mbedtls_printf(" failed\n ! mbedtls_ctr_drbg_seed returned %d\n", ret);
103 goto exit;
104 }
105
106 mbedtls_printf(" ok\n");
107
108 /*
109 * 0. Initialize certificates
110 */
111 mbedtls_printf(" . Loading the CA root certificate ...");
112 fflush(stdout);
113
114 ret = mbedtls_x509_crt_parse(&cacert, (const unsigned char *) mbedtls_test_cas_pem,
115 mbedtls_test_cas_pem_len);
116 if (ret < 0) {
117 mbedtls_printf(" failed\n ! mbedtls_x509_crt_parse returned -0x%x\n\n",
118 (unsigned int) -ret);
119 goto exit;
120 }
121
122 mbedtls_printf(" ok (%d skipped)\n", ret);
123
124 /*
125 * 1. Start the connection
126 */
127 mbedtls_printf(" . Connecting to tcp/%s/%s...", SERVER_NAME, SERVER_PORT);
128 fflush(stdout);
129
130 if ((ret = mbedtls_net_connect(&server_fd, SERVER_NAME,
131 SERVER_PORT, MBEDTLS_NET_PROTO_TCP)) != 0) {
132 mbedtls_printf(" failed\n ! mbedtls_net_connect returned %d\n\n", ret);
133 goto exit;
134 }
135
136 mbedtls_printf(" ok\n");
137
138 /*
139 * 2. Setup stuff
140 */
141 mbedtls_printf(" . Setting up the SSL/TLS structure...");
142 fflush(stdout);
143
144 if ((ret = mbedtls_ssl_config_defaults(&conf,
145 MBEDTLS_SSL_IS_CLIENT,
146 MBEDTLS_SSL_TRANSPORT_STREAM,
147 MBEDTLS_SSL_PRESET_DEFAULT)) != 0) {
148 mbedtls_printf(" failed\n ! mbedtls_ssl_config_defaults returned %d\n\n", ret);
149 goto exit;
150 }
151
152 mbedtls_printf(" ok\n");
153
154 /* OPTIONAL is not optimal for security,
155 * but makes interop easier in this simplified example */
156 mbedtls_ssl_conf_authmode(&conf, MBEDTLS_SSL_VERIFY_OPTIONAL);
157 mbedtls_ssl_conf_ca_chain(&conf, &cacert, NULL);
158 mbedtls_ssl_conf_rng(&conf, mbedtls_ctr_drbg_random, &ctr_drbg);
159 mbedtls_ssl_conf_dbg(&conf, my_debug, stdout);
160
161 if ((ret = mbedtls_ssl_setup(&ssl, &conf)) != 0) {
162 mbedtls_printf(" failed\n ! mbedtls_ssl_setup returned %d\n\n", ret);
163 goto exit;
164 }
165
166 if ((ret = mbedtls_ssl_set_hostname(&ssl, SERVER_NAME)) != 0) {
167 mbedtls_printf(" failed\n ! mbedtls_ssl_set_hostname returned %d\n\n", ret);
168 goto exit;
169 }
170
171 mbedtls_ssl_set_bio(&ssl, &server_fd, mbedtls_net_send, mbedtls_net_recv, NULL);
172
173 /*
174 * 4. Handshake
175 */
176 mbedtls_printf(" . Performing the SSL/TLS handshake...");
177 fflush(stdout);
178
179 while ((ret = mbedtls_ssl_handshake(&ssl)) != 0) {
180 if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
181 mbedtls_printf(" failed\n ! mbedtls_ssl_handshake returned -0x%x\n\n",
182 (unsigned int) -ret);
183 goto exit;
184 }
185 }
186
187 mbedtls_printf(" ok\n");
188
189 /*
190 * 5. Verify the server certificate
191 */
192 mbedtls_printf(" . Verifying peer X.509 certificate...");
193
194 /* In real life, we probably want to bail out when ret != 0 */
195 if ((flags = mbedtls_ssl_get_verify_result(&ssl)) != 0) {
196 #if !defined(MBEDTLS_X509_REMOVE_INFO)
197 char vrfy_buf[512];
198 #endif
199
200 mbedtls_printf(" failed\n");
201
202 #if !defined(MBEDTLS_X509_REMOVE_INFO)
203 mbedtls_x509_crt_verify_info(vrfy_buf, sizeof(vrfy_buf), " ! ", flags);
204
205 mbedtls_printf("%s\n", vrfy_buf);
206 #endif
207 } else {
208 mbedtls_printf(" ok\n");
209 }
210
211 /*
212 * 3. Write the GET request
213 */
214 mbedtls_printf(" > Write to server:");
215 fflush(stdout);
216
217 len = sprintf((char *) buf, GET_REQUEST);
218
219 while ((ret = mbedtls_ssl_write(&ssl, buf, len)) <= 0) {
220 if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
221 mbedtls_printf(" failed\n ! mbedtls_ssl_write returned %d\n\n", ret);
222 goto exit;
223 }
224 }
225
226 len = ret;
227 mbedtls_printf(" %d bytes written\n\n%s", len, (char *) buf);
228
229 /*
230 * 7. Read the HTTP response
231 */
232 mbedtls_printf(" < Read from server:");
233 fflush(stdout);
234
235 do {
236 len = sizeof(buf) - 1;
237 memset(buf, 0, sizeof(buf));
238 ret = mbedtls_ssl_read(&ssl, buf, len);
239
240 if (ret == MBEDTLS_ERR_SSL_WANT_READ || ret == MBEDTLS_ERR_SSL_WANT_WRITE) {
241 continue;
242 }
243
244 if (ret == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY) {
245 break;
246 }
247
248 if (ret < 0) {
249 mbedtls_printf("failed\n ! mbedtls_ssl_read returned %d\n\n", ret);
250 break;
251 }
252
253 if (ret == 0) {
254 mbedtls_printf("\n\nEOF\n\n");
255 break;
256 }
257
258 len = ret;
259 mbedtls_printf(" %d bytes read\n\n%s", len, (char *) buf);
260 } while (1);
261
262 mbedtls_ssl_close_notify(&ssl);
263
264 exit_code = MBEDTLS_EXIT_SUCCESS;
265
266 exit:
267
268 #ifdef MBEDTLS_ERROR_C
269 if (exit_code != MBEDTLS_EXIT_SUCCESS) {
270 char error_buf[100];
271 mbedtls_strerror(ret, error_buf, 100);
272 mbedtls_printf("Last error was: %d - %s\n\n", ret, error_buf);
273 }
274 #endif
275
276 mbedtls_net_free(&server_fd);
277
278 mbedtls_x509_crt_free(&cacert);
279 mbedtls_ssl_free(&ssl);
280 mbedtls_ssl_config_free(&conf);
281 mbedtls_ctr_drbg_free(&ctr_drbg);
282 mbedtls_entropy_free(&entropy);
283
284 mbedtls_exit(exit_code);
285 }
286 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_ENTROPY_C && MBEDTLS_SSL_TLS_C &&
287 MBEDTLS_SSL_CLI_C && MBEDTLS_NET_C && MBEDTLS_RSA_C &&
288 MBEDTLS_PEM_PARSE_C && MBEDTLS_CTR_DRBG_C && MBEDTLS_X509_CRT_PARSE_C */
289
