1 /*
2 * Key generation application
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 #if defined(MBEDTLS_PLATFORM_C)
23 #include "mbedtls/platform.h"
24 #else
25 #include <stdio.h>
26 #include <stdlib.h>
27 #define mbedtls_printf printf
28 #define mbedtls_exit exit
29 #define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
30 #define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
31 #endif /* MBEDTLS_PLATFORM_C */
32
33 #if defined(MBEDTLS_PK_WRITE_C) && defined(MBEDTLS_FS_IO) && \
34 defined(MBEDTLS_ENTROPY_C) && defined(MBEDTLS_CTR_DRBG_C)
35 #include "mbedtls/error.h"
36 #include "mbedtls/pk.h"
37 #include "mbedtls/ecdsa.h"
38 #include "mbedtls/rsa.h"
39 #include "mbedtls/error.h"
40 #include "mbedtls/entropy.h"
41 #include "mbedtls/ctr_drbg.h"
42
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46
47 #if !defined(_WIN32)
48 #include <unistd.h>
49
50 #define DEV_RANDOM_THRESHOLD 32
51
dev_random_entropy_poll(void * data,unsigned char * output,size_t len,size_t * olen)52 int dev_random_entropy_poll( void *data, unsigned char *output,
53 size_t len, size_t *olen )
54 {
55 FILE *file;
56 size_t ret, left = len;
57 unsigned char *p = output;
58 ((void) data);
59
60 *olen = 0;
61
62 file = fopen( "/dev/random", "rb" );
63 if( file == NULL )
64 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
65
66 while( left > 0 )
67 {
68 /* /dev/random can return much less than requested. If so, try again */
69 ret = fread( p, 1, left, file );
70 if( ret == 0 && ferror( file ) )
71 {
72 fclose( file );
73 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
74 }
75
76 p += ret;
77 left -= ret;
78 sleep( 1 );
79 }
80 fclose( file );
81 *olen = len;
82
83 return( 0 );
84 }
85 #endif /* !_WIN32 */
86 #endif
87
88 #if defined(MBEDTLS_ECP_C)
89 #define DFL_EC_CURVE mbedtls_ecp_curve_list()->grp_id
90 #else
91 #define DFL_EC_CURVE 0
92 #endif
93
94 #if !defined(_WIN32) && defined(MBEDTLS_FS_IO)
95 #define USAGE_DEV_RANDOM \
96 " use_dev_random=0|1 default: 0\n"
97 #else
98 #define USAGE_DEV_RANDOM ""
99 #endif /* !_WIN32 && MBEDTLS_FS_IO */
100
101 #define FORMAT_PEM 0
102 #define FORMAT_DER 1
103
104 #define DFL_TYPE MBEDTLS_PK_RSA
105 #define DFL_RSA_KEYSIZE 4096
106 #define DFL_FILENAME "keyfile.key"
107 #define DFL_FORMAT FORMAT_PEM
108 #define DFL_USE_DEV_RANDOM 0
109
110 #define USAGE \
111 "\n usage: gen_key param=<>...\n" \
112 "\n acceptable parameters:\n" \
113 " type=rsa|ec default: rsa\n" \
114 " rsa_keysize=%%d default: 4096\n" \
115 " ec_curve=%%s see below\n" \
116 " filename=%%s default: keyfile.key\n" \
117 " format=pem|der default: pem\n" \
118 USAGE_DEV_RANDOM \
119 "\n"
120
121 #if !defined(MBEDTLS_PK_WRITE_C) || !defined(MBEDTLS_PEM_WRITE_C) || \
122 !defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_ENTROPY_C) || \
123 !defined(MBEDTLS_CTR_DRBG_C)
main(void)124 int main( void )
125 {
126 mbedtls_printf( "MBEDTLS_PK_WRITE_C and/or MBEDTLS_FS_IO and/or "
127 "MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C and/or "
128 "MBEDTLS_PEM_WRITE_C"
129 "not defined.\n" );
130 mbedtls_exit( 0 );
131 }
132 #else
133
134
135 /*
136 * global options
137 */
138 struct options
139 {
140 int type; /* the type of key to generate */
141 int rsa_keysize; /* length of key in bits */
142 int ec_curve; /* curve identifier for EC keys */
143 const char *filename; /* filename of the key file */
144 int format; /* the output format to use */
145 int use_dev_random; /* use /dev/random as entropy source */
146 } opt;
147
write_private_key(mbedtls_pk_context * key,const char * output_file)148 static int write_private_key( mbedtls_pk_context *key, const char *output_file )
149 {
150 int ret;
151 FILE *f;
152 unsigned char output_buf[16000];
153 unsigned char *c = output_buf;
154 size_t len = 0;
155
156 memset(output_buf, 0, 16000);
157 if( opt.format == FORMAT_PEM )
158 {
159 if( ( ret = mbedtls_pk_write_key_pem( key, output_buf, 16000 ) ) != 0 )
160 return( ret );
161
162 len = strlen( (char *) output_buf );
163 }
164 else
165 {
166 if( ( ret = mbedtls_pk_write_key_der( key, output_buf, 16000 ) ) < 0 )
167 return( ret );
168
169 len = ret;
170 c = output_buf + sizeof(output_buf) - len;
171 }
172
173 if( ( f = fopen( output_file, "wb" ) ) == NULL )
174 return( -1 );
175
176 if( fwrite( c, 1, len, f ) != len )
177 {
178 fclose( f );
179 return( -1 );
180 }
181
182 fclose( f );
183
184 return( 0 );
185 }
186
main(int argc,char * argv[])187 int main( int argc, char *argv[] )
188 {
189 int ret = 1;
190 int exit_code = MBEDTLS_EXIT_FAILURE;
191 mbedtls_pk_context key;
192 char buf[1024];
193 int i;
194 char *p, *q;
195 mbedtls_mpi N, P, Q, D, E, DP, DQ, QP;
196 mbedtls_entropy_context entropy;
197 mbedtls_ctr_drbg_context ctr_drbg;
198 const char *pers = "gen_key";
199 #if defined(MBEDTLS_ECP_C)
200 const mbedtls_ecp_curve_info *curve_info;
201 #endif
202
203 /*
204 * Set to sane values
205 */
206
207 mbedtls_mpi_init( &N ); mbedtls_mpi_init( &P ); mbedtls_mpi_init( &Q );
208 mbedtls_mpi_init( &D ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &DP );
209 mbedtls_mpi_init( &DQ ); mbedtls_mpi_init( &QP );
210
211 mbedtls_pk_init( &key );
212 mbedtls_ctr_drbg_init( &ctr_drbg );
213 memset( buf, 0, sizeof( buf ) );
214
215 if( argc == 0 )
216 {
217 usage:
218 mbedtls_printf( USAGE );
219 #if defined(MBEDTLS_ECP_C)
220 mbedtls_printf( " available ec_curve values:\n" );
221 curve_info = mbedtls_ecp_curve_list();
222 mbedtls_printf( " %s (default)\n", curve_info->name );
223 while( ( ++curve_info )->name != NULL )
224 mbedtls_printf( " %s\n", curve_info->name );
225 #endif /* MBEDTLS_ECP_C */
226 goto exit;
227 }
228
229 opt.type = DFL_TYPE;
230 opt.rsa_keysize = DFL_RSA_KEYSIZE;
231 opt.ec_curve = DFL_EC_CURVE;
232 opt.filename = DFL_FILENAME;
233 opt.format = DFL_FORMAT;
234 opt.use_dev_random = DFL_USE_DEV_RANDOM;
235
236 for( i = 1; i < argc; i++ )
237 {
238 p = argv[i];
239 if( ( q = strchr( p, '=' ) ) == NULL )
240 goto usage;
241 *q++ = '\0';
242
243 if( strcmp( p, "type" ) == 0 )
244 {
245 if( strcmp( q, "rsa" ) == 0 )
246 opt.type = MBEDTLS_PK_RSA;
247 else if( strcmp( q, "ec" ) == 0 )
248 opt.type = MBEDTLS_PK_ECKEY;
249 else
250 goto usage;
251 }
252 else if( strcmp( p, "format" ) == 0 )
253 {
254 if( strcmp( q, "pem" ) == 0 )
255 opt.format = FORMAT_PEM;
256 else if( strcmp( q, "der" ) == 0 )
257 opt.format = FORMAT_DER;
258 else
259 goto usage;
260 }
261 else if( strcmp( p, "rsa_keysize" ) == 0 )
262 {
263 opt.rsa_keysize = atoi( q );
264 if( opt.rsa_keysize < 1024 ||
265 opt.rsa_keysize > MBEDTLS_MPI_MAX_BITS )
266 goto usage;
267 }
268 #if defined(MBEDTLS_ECP_C)
269 else if( strcmp( p, "ec_curve" ) == 0 )
270 {
271 if( ( curve_info = mbedtls_ecp_curve_info_from_name( q ) ) == NULL )
272 goto usage;
273 opt.ec_curve = curve_info->grp_id;
274 }
275 #endif
276 else if( strcmp( p, "filename" ) == 0 )
277 opt.filename = q;
278 else if( strcmp( p, "use_dev_random" ) == 0 )
279 {
280 opt.use_dev_random = atoi( q );
281 if( opt.use_dev_random < 0 || opt.use_dev_random > 1 )
282 goto usage;
283 }
284 else
285 goto usage;
286 }
287
288 mbedtls_printf( "\n . Seeding the random number generator..." );
289 fflush( stdout );
290
291 mbedtls_entropy_init( &entropy );
292 #if !defined(_WIN32) && defined(MBEDTLS_FS_IO)
293 if( opt.use_dev_random )
294 {
295 if( ( ret = mbedtls_entropy_add_source( &entropy, dev_random_entropy_poll,
296 NULL, DEV_RANDOM_THRESHOLD,
297 MBEDTLS_ENTROPY_SOURCE_STRONG ) ) != 0 )
298 {
299 mbedtls_printf( " failed\n ! mbedtls_entropy_add_source returned -0x%04x\n", (unsigned int) -ret );
300 goto exit;
301 }
302
303 mbedtls_printf("\n Using /dev/random, so can take a long time! " );
304 fflush( stdout );
305 }
306 #endif /* !_WIN32 && MBEDTLS_FS_IO */
307
308 if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
309 (const unsigned char *) pers,
310 strlen( pers ) ) ) != 0 )
311 {
312 mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned -0x%04x\n", (unsigned int) -ret );
313 goto exit;
314 }
315
316 /*
317 * 1.1. Generate the key
318 */
319 mbedtls_printf( "\n . Generating the private key ..." );
320 fflush( stdout );
321
322 if( ( ret = mbedtls_pk_setup( &key,
323 mbedtls_pk_info_from_type( (mbedtls_pk_type_t) opt.type ) ) ) != 0 )
324 {
325 mbedtls_printf( " failed\n ! mbedtls_pk_setup returned -0x%04x", (unsigned int) -ret );
326 goto exit;
327 }
328
329 #if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_GENPRIME)
330 if( opt.type == MBEDTLS_PK_RSA )
331 {
332 ret = mbedtls_rsa_gen_key( mbedtls_pk_rsa( key ), mbedtls_ctr_drbg_random, &ctr_drbg,
333 opt.rsa_keysize, 65537 );
334 if( ret != 0 )
335 {
336 mbedtls_printf( " failed\n ! mbedtls_rsa_gen_key returned -0x%04x", (unsigned int) -ret );
337 goto exit;
338 }
339 }
340 else
341 #endif /* MBEDTLS_RSA_C */
342 #if defined(MBEDTLS_ECP_C)
343 if( opt.type == MBEDTLS_PK_ECKEY )
344 {
345 ret = mbedtls_ecp_gen_key( (mbedtls_ecp_group_id) opt.ec_curve,
346 mbedtls_pk_ec( key ),
347 mbedtls_ctr_drbg_random, &ctr_drbg );
348 if( ret != 0 )
349 {
350 mbedtls_printf( " failed\n ! mbedtls_ecp_gen_key returned -0x%04x", (unsigned int) -ret );
351 goto exit;
352 }
353 }
354 else
355 #endif /* MBEDTLS_ECP_C */
356 {
357 mbedtls_printf( " failed\n ! key type not supported\n" );
358 goto exit;
359 }
360
361 /*
362 * 1.2 Print the key
363 */
364 mbedtls_printf( " ok\n . Key information:\n" );
365
366 #if defined(MBEDTLS_RSA_C)
367 if( mbedtls_pk_get_type( &key ) == MBEDTLS_PK_RSA )
368 {
369 mbedtls_rsa_context *rsa = mbedtls_pk_rsa( key );
370
371 if( ( ret = mbedtls_rsa_export ( rsa, &N, &P, &Q, &D, &E ) ) != 0 ||
372 ( ret = mbedtls_rsa_export_crt( rsa, &DP, &DQ, &QP ) ) != 0 )
373 {
374 mbedtls_printf( " failed\n ! could not export RSA parameters\n\n" );
375 goto exit;
376 }
377
378 mbedtls_mpi_write_file( "N: ", &N, 16, NULL );
379 mbedtls_mpi_write_file( "E: ", &E, 16, NULL );
380 mbedtls_mpi_write_file( "D: ", &D, 16, NULL );
381 mbedtls_mpi_write_file( "P: ", &P, 16, NULL );
382 mbedtls_mpi_write_file( "Q: ", &Q, 16, NULL );
383 mbedtls_mpi_write_file( "DP: ", &DP, 16, NULL );
384 mbedtls_mpi_write_file( "DQ: ", &DQ, 16, NULL );
385 mbedtls_mpi_write_file( "QP: ", &QP, 16, NULL );
386 }
387 else
388 #endif
389 #if defined(MBEDTLS_ECP_C)
390 if( mbedtls_pk_get_type( &key ) == MBEDTLS_PK_ECKEY )
391 {
392 mbedtls_ecp_keypair *ecp = mbedtls_pk_ec( key );
393 mbedtls_printf( "curve: %s\n",
394 mbedtls_ecp_curve_info_from_grp_id( ecp->MBEDTLS_PRIVATE(grp).id )->name );
395 mbedtls_mpi_write_file( "X_Q: ", &ecp->MBEDTLS_PRIVATE(Q).MBEDTLS_PRIVATE(X), 16, NULL );
396 mbedtls_mpi_write_file( "Y_Q: ", &ecp->MBEDTLS_PRIVATE(Q).MBEDTLS_PRIVATE(Y), 16, NULL );
397 mbedtls_mpi_write_file( "D: ", &ecp->MBEDTLS_PRIVATE(d) , 16, NULL );
398 }
399 else
400 #endif
401 mbedtls_printf(" ! key type not supported\n");
402
403 /*
404 * 1.3 Export key
405 */
406 mbedtls_printf( " . Writing key to file..." );
407
408 if( ( ret = write_private_key( &key, opt.filename ) ) != 0 )
409 {
410 mbedtls_printf( " failed\n" );
411 goto exit;
412 }
413
414 mbedtls_printf( " ok\n" );
415
416 exit_code = MBEDTLS_EXIT_SUCCESS;
417
418 exit:
419
420 if( exit_code != MBEDTLS_EXIT_SUCCESS )
421 {
422 #ifdef MBEDTLS_ERROR_C
423 mbedtls_strerror( ret, buf, sizeof( buf ) );
424 mbedtls_printf( " - %s\n", buf );
425 #else
426 mbedtls_printf("\n");
427 #endif
428 }
429
430 mbedtls_mpi_free( &N ); mbedtls_mpi_free( &P ); mbedtls_mpi_free( &Q );
431 mbedtls_mpi_free( &D ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &DP );
432 mbedtls_mpi_free( &DQ ); mbedtls_mpi_free( &QP );
433
434 mbedtls_pk_free( &key );
435 mbedtls_ctr_drbg_free( &ctr_drbg );
436 mbedtls_entropy_free( &entropy );
437
438 #if defined(_WIN32)
439 mbedtls_printf( " + Press Enter to exit this program.\n" );
440 fflush( stdout ); getchar();
441 #endif
442
443 mbedtls_exit( exit_code );
444 }
445 #endif /* MBEDTLS_PK_WRITE_C && MBEDTLS_PEM_WRITE_C && MBEDTLS_FS_IO &&
446 * MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */
447