1 /*
2 * Certificate request generation
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_X509_CSR_WRITE_C) || !defined(MBEDTLS_FS_IO) || \
25 !defined(MBEDTLS_PK_PARSE_C) || !defined(MBEDTLS_SHA256_C) || \
26 !defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_CTR_DRBG_C) || \
27 !defined(MBEDTLS_PEM_WRITE_C)
main(void)28 int main(void)
29 {
30 mbedtls_printf("MBEDTLS_X509_CSR_WRITE_C and/or MBEDTLS_FS_IO and/or "
31 "MBEDTLS_PK_PARSE_C and/or MBEDTLS_SHA256_C and/or "
32 "MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C "
33 "not defined.\n");
34 mbedtls_exit(0);
35 }
36 #else
37
38 #include "mbedtls/x509_csr.h"
39 #include "mbedtls/entropy.h"
40 #include "mbedtls/ctr_drbg.h"
41 #include "mbedtls/error.h"
42
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46
47 #define DFL_FILENAME "keyfile.key"
48 #define DFL_PASSWORD NULL
49 #define DFL_DEBUG_LEVEL 0
50 #define DFL_OUTPUT_FILENAME "cert.req"
51 #define DFL_SUBJECT_NAME "CN=Cert,O=mbed TLS,C=UK"
52 #define DFL_KEY_USAGE 0
53 #define DFL_FORCE_KEY_USAGE 0
54 #define DFL_NS_CERT_TYPE 0
55 #define DFL_FORCE_NS_CERT_TYPE 0
56 #define DFL_MD_ALG MBEDTLS_MD_SHA256
57
58 #define USAGE \
59 "\n usage: cert_req param=<>...\n" \
60 "\n acceptable parameters:\n" \
61 " filename=%%s default: keyfile.key\n" \
62 " password=%%s default: NULL\n" \
63 " debug_level=%%d default: 0 (disabled)\n" \
64 " output_file=%%s default: cert.req\n" \
65 " subject_name=%%s default: CN=Cert,O=mbed TLS,C=UK\n" \
66 " san=%%s default: (none)\n" \
67 " Comma-separated-list of values:\n" \
68 " DNS:value\n" \
69 " URI:value\n" \
70 " IP:value (Only IPv4 is supported)\n" \
71 " key_usage=%%s default: (empty)\n" \
72 " Comma-separated-list of values:\n" \
73 " digital_signature\n" \
74 " non_repudiation\n" \
75 " key_encipherment\n" \
76 " data_encipherment\n" \
77 " key_agreement\n" \
78 " key_cert_sign\n" \
79 " crl_sign\n" \
80 " force_key_usage=0/1 default: off\n" \
81 " Add KeyUsage even if it is empty\n" \
82 " ns_cert_type=%%s default: (empty)\n" \
83 " Comma-separated-list of values:\n" \
84 " ssl_client\n" \
85 " ssl_server\n" \
86 " email\n" \
87 " object_signing\n" \
88 " ssl_ca\n" \
89 " email_ca\n" \
90 " object_signing_ca\n" \
91 " force_ns_cert_type=0/1 default: off\n" \
92 " Add NsCertType even if it is empty\n" \
93 " md=%%s default: SHA256\n" \
94 " possible values:\n" \
95 " MD5, RIPEMD160, SHA1,\n" \
96 " SHA224, SHA256, SHA384, SHA512\n" \
97 "\n"
98
99
100 /*
101 * global options
102 */
103 struct options {
104 const char *filename; /* filename of the key file */
105 const char *password; /* password for the key file */
106 int debug_level; /* level of debugging */
107 const char *output_file; /* where to store the constructed key file */
108 const char *subject_name; /* subject name for certificate request */
109 mbedtls_x509_san_list *san_list; /* subjectAltName for certificate request */
110 unsigned char key_usage; /* key usage flags */
111 int force_key_usage; /* Force adding the KeyUsage extension */
112 unsigned char ns_cert_type; /* NS cert type */
113 int force_ns_cert_type; /* Force adding NsCertType extension */
114 mbedtls_md_type_t md_alg; /* Hash algorithm used for signature. */
115 } opt;
116
ip_string_to_bytes(const char * str,uint8_t * bytes,int maxBytes)117 static void ip_string_to_bytes(const char *str, uint8_t *bytes, int maxBytes)
118 {
119 for (int i = 0; i < maxBytes; i++) {
120 bytes[i] = (uint8_t) strtoul(str, NULL, 16);
121 str = strchr(str, '.');
122 if (str == NULL || *str == '\0') {
123 break;
124 }
125 str++;
126 }
127 }
128
write_certificate_request(mbedtls_x509write_csr * req,const char * output_file,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)129 int write_certificate_request(mbedtls_x509write_csr *req, const char *output_file,
130 int (*f_rng)(void *, unsigned char *, size_t),
131 void *p_rng)
132 {
133 int ret;
134 FILE *f;
135 unsigned char output_buf[4096];
136 size_t len = 0;
137
138 memset(output_buf, 0, 4096);
139 if ((ret = mbedtls_x509write_csr_pem(req, output_buf, 4096, f_rng, p_rng)) < 0) {
140 return ret;
141 }
142
143 len = strlen((char *) output_buf);
144
145 if ((f = fopen(output_file, "w")) == NULL) {
146 return -1;
147 }
148
149 if (fwrite(output_buf, 1, len, f) != len) {
150 fclose(f);
151 return -1;
152 }
153
154 fclose(f);
155
156 return 0;
157 }
158
main(int argc,char * argv[])159 int main(int argc, char *argv[])
160 {
161 int ret = 1;
162 int exit_code = MBEDTLS_EXIT_FAILURE;
163 mbedtls_pk_context key;
164 char buf[1024];
165 int i;
166 char *p, *q, *r, *r2;
167 mbedtls_x509write_csr req;
168 mbedtls_entropy_context entropy;
169 mbedtls_ctr_drbg_context ctr_drbg;
170 const char *pers = "csr example app";
171 mbedtls_x509_san_list *cur, *prev;
172
173 /*
174 * Set to sane values
175 */
176 mbedtls_x509write_csr_init(&req);
177 mbedtls_pk_init(&key);
178 mbedtls_ctr_drbg_init(&ctr_drbg);
179 memset(buf, 0, sizeof(buf));
180
181 if (argc < 2) {
182 usage:
183 mbedtls_printf(USAGE);
184 goto exit;
185 }
186
187 opt.filename = DFL_FILENAME;
188 opt.password = DFL_PASSWORD;
189 opt.debug_level = DFL_DEBUG_LEVEL;
190 opt.output_file = DFL_OUTPUT_FILENAME;
191 opt.subject_name = DFL_SUBJECT_NAME;
192 opt.key_usage = DFL_KEY_USAGE;
193 opt.force_key_usage = DFL_FORCE_KEY_USAGE;
194 opt.ns_cert_type = DFL_NS_CERT_TYPE;
195 opt.force_ns_cert_type = DFL_FORCE_NS_CERT_TYPE;
196 opt.md_alg = DFL_MD_ALG;
197 opt.san_list = NULL;
198
199 for (i = 1; i < argc; i++) {
200 p = argv[i];
201 if ((q = strchr(p, '=')) == NULL) {
202 goto usage;
203 }
204 *q++ = '\0';
205 if (strcmp(p, "filename") == 0) {
206 opt.filename = q;
207 } else if (strcmp(p, "password") == 0) {
208 opt.password = q;
209 } else if (strcmp(p, "output_file") == 0) {
210 opt.output_file = q;
211 } else if (strcmp(p, "debug_level") == 0) {
212 opt.debug_level = atoi(q);
213 if (opt.debug_level < 0 || opt.debug_level > 65535) {
214 goto usage;
215 }
216 } else if (strcmp(p, "subject_name") == 0) {
217 opt.subject_name = q;
218 } else if (strcmp(p, "san") == 0) {
219 prev = NULL;
220
221 while (q != NULL) {
222 uint8_t ip[4] = { 0 };
223
224 if ((r = strchr(q, ';')) != NULL) {
225 *r++ = '\0';
226 }
227
228 cur = mbedtls_calloc(1, sizeof(mbedtls_x509_san_list));
229 if (cur == NULL) {
230 mbedtls_printf("Not enough memory for subjectAltName list\n");
231 goto usage;
232 }
233
234 cur->next = NULL;
235
236 if ((r2 = strchr(q, ':')) != NULL) {
237 *r2++ = '\0';
238 }
239
240 if (strcmp(q, "URI") == 0) {
241 cur->node.type = MBEDTLS_X509_SAN_UNIFORM_RESOURCE_IDENTIFIER;
242 } else if (strcmp(q, "DNS") == 0) {
243 cur->node.type = MBEDTLS_X509_SAN_DNS_NAME;
244 } else if (strcmp(q, "IP") == 0) {
245 cur->node.type = MBEDTLS_X509_SAN_IP_ADDRESS;
246 ip_string_to_bytes(r2, ip, 4);
247 } else {
248 mbedtls_free(cur);
249 goto usage;
250 }
251
252 if (strcmp(q, "IP") == 0) {
253 cur->node.san.unstructured_name.p = (unsigned char *) ip;
254 cur->node.san.unstructured_name.len = sizeof(ip);
255 } else {
256 q = r2;
257 cur->node.san.unstructured_name.p = (unsigned char *) q;
258 cur->node.san.unstructured_name.len = strlen(q);
259 }
260
261 if (prev == NULL) {
262 opt.san_list = cur;
263 } else {
264 prev->next = cur;
265 }
266
267 prev = cur;
268 q = r;
269 }
270
271 } else if (strcmp(p, "md") == 0) {
272 const mbedtls_md_info_t *md_info =
273 mbedtls_md_info_from_string(q);
274 if (md_info == NULL) {
275 mbedtls_printf("Invalid argument for option %s\n", p);
276 goto usage;
277 }
278 opt.md_alg = mbedtls_md_get_type(md_info);
279 } else if (strcmp(p, "key_usage") == 0) {
280 while (q != NULL) {
281 if ((r = strchr(q, ',')) != NULL) {
282 *r++ = '\0';
283 }
284
285 if (strcmp(q, "digital_signature") == 0) {
286 opt.key_usage |= MBEDTLS_X509_KU_DIGITAL_SIGNATURE;
287 } else if (strcmp(q, "non_repudiation") == 0) {
288 opt.key_usage |= MBEDTLS_X509_KU_NON_REPUDIATION;
289 } else if (strcmp(q, "key_encipherment") == 0) {
290 opt.key_usage |= MBEDTLS_X509_KU_KEY_ENCIPHERMENT;
291 } else if (strcmp(q, "data_encipherment") == 0) {
292 opt.key_usage |= MBEDTLS_X509_KU_DATA_ENCIPHERMENT;
293 } else if (strcmp(q, "key_agreement") == 0) {
294 opt.key_usage |= MBEDTLS_X509_KU_KEY_AGREEMENT;
295 } else if (strcmp(q, "key_cert_sign") == 0) {
296 opt.key_usage |= MBEDTLS_X509_KU_KEY_CERT_SIGN;
297 } else if (strcmp(q, "crl_sign") == 0) {
298 opt.key_usage |= MBEDTLS_X509_KU_CRL_SIGN;
299 } else {
300 goto usage;
301 }
302
303 q = r;
304 }
305 } else if (strcmp(p, "force_key_usage") == 0) {
306 switch (atoi(q)) {
307 case 0: opt.force_key_usage = 0; break;
308 case 1: opt.force_key_usage = 1; break;
309 default: goto usage;
310 }
311 } else if (strcmp(p, "ns_cert_type") == 0) {
312 while (q != NULL) {
313 if ((r = strchr(q, ',')) != NULL) {
314 *r++ = '\0';
315 }
316
317 if (strcmp(q, "ssl_client") == 0) {
318 opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT;
319 } else if (strcmp(q, "ssl_server") == 0) {
320 opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER;
321 } else if (strcmp(q, "email") == 0) {
322 opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_EMAIL;
323 } else if (strcmp(q, "object_signing") == 0) {
324 opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING;
325 } else if (strcmp(q, "ssl_ca") == 0) {
326 opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_SSL_CA;
327 } else if (strcmp(q, "email_ca") == 0) {
328 opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA;
329 } else if (strcmp(q, "object_signing_ca") == 0) {
330 opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA;
331 } else {
332 goto usage;
333 }
334
335 q = r;
336 }
337 } else if (strcmp(p, "force_ns_cert_type") == 0) {
338 switch (atoi(q)) {
339 case 0: opt.force_ns_cert_type = 0; break;
340 case 1: opt.force_ns_cert_type = 1; break;
341 default: goto usage;
342 }
343 } else {
344 goto usage;
345 }
346 }
347
348 /* Set the MD algorithm to use for the signature in the CSR */
349 mbedtls_x509write_csr_set_md_alg(&req, opt.md_alg);
350
351 /* Set the Key Usage Extension flags in the CSR */
352 if (opt.key_usage || opt.force_key_usage == 1) {
353 ret = mbedtls_x509write_csr_set_key_usage(&req, opt.key_usage);
354
355 if (ret != 0) {
356 mbedtls_printf(" failed\n ! mbedtls_x509write_csr_set_key_usage returned %d", ret);
357 goto exit;
358 }
359 }
360
361 /* Set the Cert Type flags in the CSR */
362 if (opt.ns_cert_type || opt.force_ns_cert_type == 1) {
363 ret = mbedtls_x509write_csr_set_ns_cert_type(&req, opt.ns_cert_type);
364
365 if (ret != 0) {
366 mbedtls_printf(" failed\n ! mbedtls_x509write_csr_set_ns_cert_type returned %d", ret);
367 goto exit;
368 }
369 }
370
371 /* Set the SubjectAltName in the CSR */
372 if (opt.san_list != NULL) {
373 ret = mbedtls_x509write_csr_set_subject_alternative_name(&req, opt.san_list);
374
375 if (ret != 0) {
376 mbedtls_printf(
377 " failed\n ! mbedtls_x509write_csr_set_subject_alternative_name returned %d",
378 ret);
379 goto exit;
380 }
381 }
382
383 /*
384 * 0. Seed the PRNG
385 */
386 mbedtls_printf(" . Seeding the random number generator...");
387 fflush(stdout);
388
389 mbedtls_entropy_init(&entropy);
390 if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy,
391 (const unsigned char *) pers,
392 strlen(pers))) != 0) {
393 mbedtls_printf(" failed\n ! mbedtls_ctr_drbg_seed returned %d", ret);
394 goto exit;
395 }
396
397 mbedtls_printf(" ok\n");
398
399 /*
400 * 1.0. Check the subject name for validity
401 */
402 mbedtls_printf(" . Checking subject name...");
403 fflush(stdout);
404
405 if ((ret = mbedtls_x509write_csr_set_subject_name(&req, opt.subject_name)) != 0) {
406 mbedtls_printf(" failed\n ! mbedtls_x509write_csr_set_subject_name returned %d", ret);
407 goto exit;
408 }
409
410 mbedtls_printf(" ok\n");
411
412 /*
413 * 1.1. Load the key
414 */
415 mbedtls_printf(" . Loading the private key ...");
416 fflush(stdout);
417
418 ret = mbedtls_pk_parse_keyfile(&key, opt.filename, opt.password,
419 mbedtls_ctr_drbg_random, &ctr_drbg);
420
421 if (ret != 0) {
422 mbedtls_printf(" failed\n ! mbedtls_pk_parse_keyfile returned %d", ret);
423 goto exit;
424 }
425
426 mbedtls_x509write_csr_set_key(&req, &key);
427
428 mbedtls_printf(" ok\n");
429
430 /*
431 * 1.2. Writing the request
432 */
433 mbedtls_printf(" . Writing the certificate request ...");
434 fflush(stdout);
435
436 if ((ret = write_certificate_request(&req, opt.output_file,
437 mbedtls_ctr_drbg_random, &ctr_drbg)) != 0) {
438 mbedtls_printf(" failed\n ! write_certificate_request %d", ret);
439 goto exit;
440 }
441
442 mbedtls_printf(" ok\n");
443
444 exit_code = MBEDTLS_EXIT_SUCCESS;
445
446 exit:
447
448 if (exit_code != MBEDTLS_EXIT_SUCCESS) {
449 #ifdef MBEDTLS_ERROR_C
450 mbedtls_strerror(ret, buf, sizeof(buf));
451 mbedtls_printf(" - %s\n", buf);
452 #else
453 mbedtls_printf("\n");
454 #endif
455 }
456
457 mbedtls_x509write_csr_free(&req);
458 mbedtls_pk_free(&key);
459 mbedtls_ctr_drbg_free(&ctr_drbg);
460 mbedtls_entropy_free(&entropy);
461
462 cur = opt.san_list;
463 while (cur != NULL) {
464 prev = cur;
465 cur = cur->next;
466 mbedtls_free(prev);
467 }
468
469
470 mbedtls_exit(exit_code);
471 }
472 #endif /* MBEDTLS_X509_CSR_WRITE_C && MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO &&
473 MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C && MBEDTLS_PEM_WRITE_C */
474
