1 /*
2 * Key generation application
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6 */
7
8 #if !defined(MBEDTLS_CONFIG_FILE)
9 #include "mbedtls/config.h"
10 #else
11 #include MBEDTLS_CONFIG_FILE
12 #endif
13
14 #include "mbedtls/platform.h"
15
16 #if defined(MBEDTLS_PK_WRITE_C) && defined(MBEDTLS_FS_IO) && \
17 defined(MBEDTLS_ENTROPY_C) && defined(MBEDTLS_CTR_DRBG_C)
18 #include "mbedtls/error.h"
19 #include "mbedtls/pk.h"
20 #include "mbedtls/ecdsa.h"
21 #include "mbedtls/rsa.h"
22 #include "mbedtls/error.h"
23 #include "mbedtls/entropy.h"
24 #include "mbedtls/ctr_drbg.h"
25
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29
30 #if !defined(_WIN32)
31 #include <unistd.h>
32
33 #define DEV_RANDOM_THRESHOLD 32
34
dev_random_entropy_poll(void * data,unsigned char * output,size_t len,size_t * olen)35 int dev_random_entropy_poll(void *data, unsigned char *output,
36 size_t len, size_t *olen)
37 {
38 FILE *file;
39 size_t ret, left = len;
40 unsigned char *p = output;
41 ((void) data);
42
43 *olen = 0;
44
45 file = fopen("/dev/random", "rb");
46 if (file == NULL) {
47 return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
48 }
49
50 while (left > 0) {
51 /* /dev/random can return much less than requested. If so, try again */
52 ret = fread(p, 1, left, file);
53 if (ret == 0 && ferror(file)) {
54 fclose(file);
55 return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
56 }
57
58 p += ret;
59 left -= ret;
60 sleep(1);
61 }
62 fclose(file);
63 *olen = len;
64
65 return 0;
66 }
67 #endif /* !_WIN32 */
68 #endif
69
70 #if defined(MBEDTLS_ECP_C)
71 #define DFL_EC_CURVE mbedtls_ecp_curve_list()->grp_id
72 #else
73 #define DFL_EC_CURVE 0
74 #endif
75
76 #if !defined(_WIN32) && defined(MBEDTLS_FS_IO)
77 #define USAGE_DEV_RANDOM \
78 " use_dev_random=0|1 default: 0\n"
79 #else
80 #define USAGE_DEV_RANDOM ""
81 #endif /* !_WIN32 && MBEDTLS_FS_IO */
82
83 #define FORMAT_PEM 0
84 #define FORMAT_DER 1
85
86 #define DFL_TYPE MBEDTLS_PK_RSA
87 #define DFL_RSA_KEYSIZE 4096
88 #define DFL_FILENAME "keyfile.key"
89 #define DFL_FORMAT FORMAT_PEM
90 #define DFL_USE_DEV_RANDOM 0
91
92 #define USAGE \
93 "\n usage: gen_key param=<>...\n" \
94 "\n acceptable parameters:\n" \
95 " type=rsa|ec default: rsa\n" \
96 " rsa_keysize=%%d default: 4096\n" \
97 " ec_curve=%%s see below\n" \
98 " filename=%%s default: keyfile.key\n" \
99 " format=pem|der default: pem\n" \
100 USAGE_DEV_RANDOM \
101 "\n"
102
103 #if !defined(MBEDTLS_PK_WRITE_C) || !defined(MBEDTLS_PEM_WRITE_C) || \
104 !defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_ENTROPY_C) || \
105 !defined(MBEDTLS_CTR_DRBG_C)
main(void)106 int main(void)
107 {
108 mbedtls_printf("MBEDTLS_PK_WRITE_C and/or MBEDTLS_FS_IO and/or "
109 "MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C and/or "
110 "MBEDTLS_PEM_WRITE_C"
111 "not defined.\n");
112 mbedtls_exit(0);
113 }
114 #else
115
116
117 /*
118 * global options
119 */
120 struct options {
121 int type; /* the type of key to generate */
122 int rsa_keysize; /* length of key in bits */
123 int ec_curve; /* curve identifier for EC keys */
124 const char *filename; /* filename of the key file */
125 int format; /* the output format to use */
126 int use_dev_random; /* use /dev/random as entropy source */
127 } opt;
128
write_private_key(mbedtls_pk_context * key,const char * output_file)129 static int write_private_key(mbedtls_pk_context *key, const char *output_file)
130 {
131 int ret;
132 FILE *f;
133 unsigned char output_buf[16000];
134 unsigned char *c = output_buf;
135 size_t len = 0;
136
137 memset(output_buf, 0, 16000);
138 if (opt.format == FORMAT_PEM) {
139 if ((ret = mbedtls_pk_write_key_pem(key, output_buf, 16000)) != 0) {
140 return ret;
141 }
142
143 len = strlen((char *) output_buf);
144 } else {
145 if ((ret = mbedtls_pk_write_key_der(key, output_buf, 16000)) < 0) {
146 return ret;
147 }
148
149 len = ret;
150 c = output_buf + sizeof(output_buf) - len;
151 }
152
153 if ((f = fopen(output_file, "wb")) == NULL) {
154 return -1;
155 }
156
157 if (fwrite(c, 1, len, f) != len) {
158 fclose(f);
159 return -1;
160 }
161
162 fclose(f);
163
164 return 0;
165 }
166
main(int argc,char * argv[])167 int main(int argc, char *argv[])
168 {
169 int ret = 1;
170 int exit_code = MBEDTLS_EXIT_FAILURE;
171 mbedtls_pk_context key;
172 char buf[1024];
173 int i;
174 char *p, *q;
175 mbedtls_mpi N, P, Q, D, E, DP, DQ, QP;
176 mbedtls_entropy_context entropy;
177 mbedtls_ctr_drbg_context ctr_drbg;
178 const char *pers = "gen_key";
179 #if defined(MBEDTLS_ECP_C)
180 const mbedtls_ecp_curve_info *curve_info;
181 #endif
182
183 /*
184 * Set to sane values
185 */
186
187 mbedtls_mpi_init(&N); mbedtls_mpi_init(&P); mbedtls_mpi_init(&Q);
188 mbedtls_mpi_init(&D); mbedtls_mpi_init(&E); mbedtls_mpi_init(&DP);
189 mbedtls_mpi_init(&DQ); mbedtls_mpi_init(&QP);
190
191 mbedtls_pk_init(&key);
192 mbedtls_ctr_drbg_init(&ctr_drbg);
193 memset(buf, 0, sizeof(buf));
194
195 #if defined(MBEDTLS_USE_PSA_CRYPTO)
196 psa_status_t status = psa_crypto_init();
197 if (status != PSA_SUCCESS) {
198 mbedtls_fprintf(stderr, "Failed to initialize PSA Crypto implementation: %d\n",
199 (int) status);
200 goto exit;
201 }
202 #endif /* MBEDTLS_USE_PSA_CRYPTO */
203
204 if (argc < 2) {
205 usage:
206 mbedtls_printf(USAGE);
207 #if defined(MBEDTLS_ECP_C)
208 mbedtls_printf(" available ec_curve values:\n");
209 curve_info = mbedtls_ecp_curve_list();
210 mbedtls_printf(" %s (default)\n", curve_info->name);
211 while ((++curve_info)->name != NULL) {
212 mbedtls_printf(" %s\n", curve_info->name);
213 }
214 #endif /* MBEDTLS_ECP_C */
215 goto exit;
216 }
217
218 opt.type = DFL_TYPE;
219 opt.rsa_keysize = DFL_RSA_KEYSIZE;
220 opt.ec_curve = DFL_EC_CURVE;
221 opt.filename = DFL_FILENAME;
222 opt.format = DFL_FORMAT;
223 opt.use_dev_random = DFL_USE_DEV_RANDOM;
224
225 for (i = 1; i < argc; i++) {
226 p = argv[i];
227 if ((q = strchr(p, '=')) == NULL) {
228 goto usage;
229 }
230 *q++ = '\0';
231
232 if (strcmp(p, "type") == 0) {
233 if (strcmp(q, "rsa") == 0) {
234 opt.type = MBEDTLS_PK_RSA;
235 } else if (strcmp(q, "ec") == 0) {
236 opt.type = MBEDTLS_PK_ECKEY;
237 } else {
238 goto usage;
239 }
240 } else if (strcmp(p, "format") == 0) {
241 if (strcmp(q, "pem") == 0) {
242 opt.format = FORMAT_PEM;
243 } else if (strcmp(q, "der") == 0) {
244 opt.format = FORMAT_DER;
245 } else {
246 goto usage;
247 }
248 } else if (strcmp(p, "rsa_keysize") == 0) {
249 opt.rsa_keysize = atoi(q);
250 if (opt.rsa_keysize < 1024 ||
251 opt.rsa_keysize > MBEDTLS_MPI_MAX_BITS) {
252 goto usage;
253 }
254 }
255 #if defined(MBEDTLS_ECP_C)
256 else if (strcmp(p, "ec_curve") == 0) {
257 if ((curve_info = mbedtls_ecp_curve_info_from_name(q)) == NULL) {
258 goto usage;
259 }
260 opt.ec_curve = curve_info->grp_id;
261 }
262 #endif
263 else if (strcmp(p, "filename") == 0) {
264 opt.filename = q;
265 } else if (strcmp(p, "use_dev_random") == 0) {
266 opt.use_dev_random = atoi(q);
267 if (opt.use_dev_random < 0 || opt.use_dev_random > 1) {
268 goto usage;
269 }
270 } else {
271 goto usage;
272 }
273 }
274
275 mbedtls_printf("\n . Seeding the random number generator...");
276 fflush(stdout);
277
278 mbedtls_entropy_init(&entropy);
279 #if !defined(_WIN32) && defined(MBEDTLS_FS_IO)
280 if (opt.use_dev_random) {
281 if ((ret = mbedtls_entropy_add_source(&entropy, dev_random_entropy_poll,
282 NULL, DEV_RANDOM_THRESHOLD,
283 MBEDTLS_ENTROPY_SOURCE_STRONG)) != 0) {
284 mbedtls_printf(" failed\n ! mbedtls_entropy_add_source returned -0x%04x\n",
285 (unsigned int) -ret);
286 goto exit;
287 }
288
289 mbedtls_printf("\n Using /dev/random, so can take a long time! ");
290 fflush(stdout);
291 }
292 #endif /* !_WIN32 && MBEDTLS_FS_IO */
293
294 if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy,
295 (const unsigned char *) pers,
296 strlen(pers))) != 0) {
297 mbedtls_printf(" failed\n ! mbedtls_ctr_drbg_seed returned -0x%04x\n",
298 (unsigned int) -ret);
299 goto exit;
300 }
301
302 /*
303 * 1.1. Generate the key
304 */
305 mbedtls_printf("\n . Generating the private key ...");
306 fflush(stdout);
307
308 if ((ret = mbedtls_pk_setup(&key,
309 mbedtls_pk_info_from_type((mbedtls_pk_type_t) opt.type))) != 0) {
310 mbedtls_printf(" failed\n ! mbedtls_pk_setup returned -0x%04x", (unsigned int) -ret);
311 goto exit;
312 }
313
314 #if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_GENPRIME)
315 if (opt.type == MBEDTLS_PK_RSA) {
316 ret = mbedtls_rsa_gen_key(mbedtls_pk_rsa(key), mbedtls_ctr_drbg_random, &ctr_drbg,
317 opt.rsa_keysize, 65537);
318 if (ret != 0) {
319 mbedtls_printf(" failed\n ! mbedtls_rsa_gen_key returned -0x%04x",
320 (unsigned int) -ret);
321 goto exit;
322 }
323 } else
324 #endif /* MBEDTLS_RSA_C */
325 #if defined(MBEDTLS_ECP_C)
326 if (opt.type == MBEDTLS_PK_ECKEY) {
327 ret = mbedtls_ecp_gen_key((mbedtls_ecp_group_id) opt.ec_curve,
328 mbedtls_pk_ec(key),
329 mbedtls_ctr_drbg_random, &ctr_drbg);
330 if (ret != 0) {
331 mbedtls_printf(" failed\n ! mbedtls_ecp_gen_key returned -0x%04x",
332 (unsigned int) -ret);
333 goto exit;
334 }
335 } else
336 #endif /* MBEDTLS_ECP_C */
337 {
338 mbedtls_printf(" failed\n ! key type not supported\n");
339 goto exit;
340 }
341
342 /*
343 * 1.2 Print the key
344 */
345 mbedtls_printf(" ok\n . Key information:\n");
346
347 #if defined(MBEDTLS_RSA_C)
348 if (mbedtls_pk_get_type(&key) == MBEDTLS_PK_RSA) {
349 mbedtls_rsa_context *rsa = mbedtls_pk_rsa(key);
350
351 if ((ret = mbedtls_rsa_export(rsa, &N, &P, &Q, &D, &E)) != 0 ||
352 (ret = mbedtls_rsa_export_crt(rsa, &DP, &DQ, &QP)) != 0) {
353 mbedtls_printf(" failed\n ! could not export RSA parameters\n\n");
354 goto exit;
355 }
356
357 mbedtls_mpi_write_file("N: ", &N, 16, NULL);
358 mbedtls_mpi_write_file("E: ", &E, 16, NULL);
359 mbedtls_mpi_write_file("D: ", &D, 16, NULL);
360 mbedtls_mpi_write_file("P: ", &P, 16, NULL);
361 mbedtls_mpi_write_file("Q: ", &Q, 16, NULL);
362 mbedtls_mpi_write_file("DP: ", &DP, 16, NULL);
363 mbedtls_mpi_write_file("DQ: ", &DQ, 16, NULL);
364 mbedtls_mpi_write_file("QP: ", &QP, 16, NULL);
365 } else
366 #endif
367 #if defined(MBEDTLS_ECP_C)
368 if (mbedtls_pk_get_type(&key) == MBEDTLS_PK_ECKEY) {
369 mbedtls_ecp_keypair *ecp = mbedtls_pk_ec(key);
370 mbedtls_printf("curve: %s\n",
371 mbedtls_ecp_curve_info_from_grp_id(ecp->grp.id)->name);
372 mbedtls_mpi_write_file("X_Q: ", &ecp->Q.X, 16, NULL);
373 mbedtls_mpi_write_file("Y_Q: ", &ecp->Q.Y, 16, NULL);
374 mbedtls_mpi_write_file("D: ", &ecp->d, 16, NULL);
375 } else
376 #endif
377 mbedtls_printf(" ! key type not supported\n");
378
379 /*
380 * 1.3 Export key
381 */
382 mbedtls_printf(" . Writing key to file...");
383
384 if ((ret = write_private_key(&key, opt.filename)) != 0) {
385 mbedtls_printf(" failed\n");
386 goto exit;
387 }
388
389 mbedtls_printf(" ok\n");
390
391 exit_code = MBEDTLS_EXIT_SUCCESS;
392
393 exit:
394
395 if (exit_code != MBEDTLS_EXIT_SUCCESS) {
396 #ifdef MBEDTLS_ERROR_C
397 mbedtls_strerror(ret, buf, sizeof(buf));
398 mbedtls_printf(" - %s\n", buf);
399 #else
400 mbedtls_printf("\n");
401 #endif
402 }
403
404 mbedtls_mpi_free(&N); mbedtls_mpi_free(&P); mbedtls_mpi_free(&Q);
405 mbedtls_mpi_free(&D); mbedtls_mpi_free(&E); mbedtls_mpi_free(&DP);
406 mbedtls_mpi_free(&DQ); mbedtls_mpi_free(&QP);
407
408 mbedtls_pk_free(&key);
409 mbedtls_ctr_drbg_free(&ctr_drbg);
410 mbedtls_entropy_free(&entropy);
411 #if defined(MBEDTLS_USE_PSA_CRYPTO)
412 mbedtls_psa_crypto_free();
413 #endif /* MBEDTLS_USE_PSA_CRYPTO */
414
415 #if defined(_WIN32)
416 mbedtls_printf(" + Press Enter to exit this program.\n");
417 fflush(stdout); getchar();
418 #endif
419
420 mbedtls_exit(exit_code);
421 }
422 #endif /* MBEDTLS_PK_WRITE_C && MBEDTLS_PEM_WRITE_C && MBEDTLS_FS_IO &&
423 * MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */
424