1/*
2 *  Key writing application
3 *
4 *  Copyright The Mbed TLS Contributors
5 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6 */
7
8#include "mbedtls/build_info.h"
9
10#include "mbedtls/platform.h"
11
12#if !defined(MBEDTLS_PK_PARSE_C) || \
13    !defined(MBEDTLS_PK_WRITE_C) || \
14    !defined(MBEDTLS_FS_IO)      || \
15    !defined(MBEDTLS_ENTROPY_C)  || \
16    !defined(MBEDTLS_CTR_DRBG_C) || \
17    !defined(MBEDTLS_BIGNUM_C)
18int main(void)
19{
20    mbedtls_printf("MBEDTLS_PK_PARSE_C and/or MBEDTLS_PK_WRITE_C and/or "
21                   "MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C and/or "
22                   "MBEDTLS_FS_IO and/or MBEDTLS_BIGNUM_C not defined.\n");
23    mbedtls_exit(0);
24}
25#else
26
27#include "mbedtls/error.h"
28#include "mbedtls/pk.h"
29#include "mbedtls/error.h"
30
31#include "mbedtls/entropy.h"
32#include "mbedtls/ctr_drbg.h"
33
34#include <stdio.h>
35#include <string.h>
36
37#if defined(MBEDTLS_PEM_WRITE_C)
38#define USAGE_OUT \
39    "    output_file=%%s      default: keyfile.pem\n"   \
40    "    output_format=pem|der default: pem\n"
41#else
42#define USAGE_OUT \
43    "    output_file=%%s      default: keyfile.der\n"   \
44    "    output_format=der     default: der\n"
45#endif
46
47#if defined(MBEDTLS_PEM_WRITE_C)
48#define DFL_OUTPUT_FILENAME     "keyfile.pem"
49#define DFL_OUTPUT_FORMAT       OUTPUT_FORMAT_PEM
50#else
51#define DFL_OUTPUT_FILENAME     "keyfile.der"
52#define DFL_OUTPUT_FORMAT       OUTPUT_FORMAT_DER
53#endif
54
55#define DFL_MODE                MODE_NONE
56#define DFL_FILENAME            "keyfile.key"
57#define DFL_DEBUG_LEVEL         0
58#define DFL_OUTPUT_MODE         OUTPUT_MODE_NONE
59
60#define MODE_NONE               0
61#define MODE_PRIVATE            1
62#define MODE_PUBLIC             2
63
64#define OUTPUT_MODE_NONE               0
65#define OUTPUT_MODE_PRIVATE            1
66#define OUTPUT_MODE_PUBLIC             2
67
68#define OUTPUT_FORMAT_PEM              0
69#define OUTPUT_FORMAT_DER              1
70
71#define USAGE \
72    "\n usage: key_app_writer param=<>...\n"            \
73    "\n acceptable parameters:\n"                       \
74    "    mode=private|public default: none\n"           \
75    "    filename=%%s         default: keyfile.key\n"   \
76    "    output_mode=private|public default: none\n"    \
77    USAGE_OUT                                           \
78    "\n"
79
80
81/*
82 * global options
83 */
84struct options {
85    int mode;                   /* the mode to run the application in   */
86    const char *filename;       /* filename of the key file             */
87    int output_mode;            /* the output mode to use               */
88    const char *output_file;    /* where to store the constructed key file  */
89    int output_format;          /* the output format to use             */
90} opt;
91
92static int write_public_key(mbedtls_pk_context *key, const char *output_file)
93{
94    int ret;
95    FILE *f;
96    unsigned char output_buf[16000];
97    unsigned char *c = output_buf;
98    size_t len = 0;
99
100    memset(output_buf, 0, 16000);
101
102#if defined(MBEDTLS_PEM_WRITE_C)
103    if (opt.output_format == OUTPUT_FORMAT_PEM) {
104        if ((ret = mbedtls_pk_write_pubkey_pem(key, output_buf, 16000)) != 0) {
105            return ret;
106        }
107
108        len = strlen((char *) output_buf);
109    } else
110#endif
111    {
112        if ((ret = mbedtls_pk_write_pubkey_der(key, output_buf, 16000)) < 0) {
113            return ret;
114        }
115
116        len = ret;
117        c = output_buf + sizeof(output_buf) - len;
118    }
119
120    if ((f = fopen(output_file, "w")) == NULL) {
121        return -1;
122    }
123
124    if (fwrite(c, 1, len, f) != len) {
125        fclose(f);
126        return -1;
127    }
128
129    fclose(f);
130
131    return 0;
132}
133
134static int write_private_key(mbedtls_pk_context *key, const char *output_file)
135{
136    int ret;
137    FILE *f;
138    unsigned char output_buf[16000];
139    unsigned char *c = output_buf;
140    size_t len = 0;
141
142    memset(output_buf, 0, 16000);
143
144#if defined(MBEDTLS_PEM_WRITE_C)
145    if (opt.output_format == OUTPUT_FORMAT_PEM) {
146        if ((ret = mbedtls_pk_write_key_pem(key, output_buf, 16000)) != 0) {
147            return ret;
148        }
149
150        len = strlen((char *) output_buf);
151    } else
152#endif
153    {
154        if ((ret = mbedtls_pk_write_key_der(key, output_buf, 16000)) < 0) {
155            return ret;
156        }
157
158        len = ret;
159        c = output_buf + sizeof(output_buf) - len;
160    }
161
162    if ((f = fopen(output_file, "w")) == NULL) {
163        return -1;
164    }
165
166    if (fwrite(c, 1, len, f) != len) {
167        fclose(f);
168        return -1;
169    }
170
171    fclose(f);
172
173    return 0;
174}
175
176#if defined(MBEDTLS_ECP_C)
177static int show_ecp_key(const mbedtls_ecp_keypair *ecp, int has_private)
178{
179    int ret = 0;
180
181    const mbedtls_ecp_curve_info *curve_info =
182        mbedtls_ecp_curve_info_from_grp_id(
183            mbedtls_ecp_keypair_get_group_id(ecp));
184    mbedtls_printf("curve: %s\n", curve_info->name);
185
186    mbedtls_ecp_group grp;
187    mbedtls_ecp_group_init(&grp);
188    mbedtls_mpi D;
189    mbedtls_mpi_init(&D);
190    mbedtls_ecp_point pt;
191    mbedtls_ecp_point_init(&pt);
192    mbedtls_mpi X, Y;
193    mbedtls_mpi_init(&X); mbedtls_mpi_init(&Y);
194
195    MBEDTLS_MPI_CHK(mbedtls_ecp_export(ecp, &grp,
196                                       (has_private ? &D : NULL),
197                                       &pt));
198
199    unsigned char point_bin[MBEDTLS_ECP_MAX_PT_LEN];
200    size_t len = 0;
201    MBEDTLS_MPI_CHK(mbedtls_ecp_point_write_binary(
202                        &grp, &pt, MBEDTLS_ECP_PF_UNCOMPRESSED,
203                        &len, point_bin, sizeof(point_bin)));
204    switch (mbedtls_ecp_get_type(&grp)) {
205        case MBEDTLS_ECP_TYPE_SHORT_WEIERSTRASS:
206            if ((len & 1) == 0 || point_bin[0] != 0x04) {
207                /* Point in an unxepected format. This shouldn't happen. */
208                ret = -1;
209                goto cleanup;
210            }
211            MBEDTLS_MPI_CHK(
212                mbedtls_mpi_read_binary(&X, point_bin + 1, len / 2));
213            MBEDTLS_MPI_CHK(
214                mbedtls_mpi_read_binary(&Y, point_bin + 1 + len / 2, len / 2));
215            mbedtls_mpi_write_file("X_Q:   ", &X, 16, NULL);
216            mbedtls_mpi_write_file("Y_Q:   ", &Y, 16, NULL);
217            break;
218        case MBEDTLS_ECP_TYPE_MONTGOMERY:
219            MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&X, point_bin, len));
220            mbedtls_mpi_write_file("X_Q:   ", &X, 16, NULL);
221            break;
222        default:
223            mbedtls_printf(
224                "This program does not yet support listing coordinates for this curve type.\n");
225            break;
226    }
227
228    if (has_private) {
229        mbedtls_mpi_write_file("D:     ", &D, 16, NULL);
230    }
231
232cleanup:
233    mbedtls_ecp_group_free(&grp);
234    mbedtls_mpi_free(&D);
235    mbedtls_ecp_point_free(&pt);
236    mbedtls_mpi_free(&X); mbedtls_mpi_free(&Y);
237    return ret;
238}
239#endif
240
241int main(int argc, char *argv[])
242{
243    int ret = 1;
244    int exit_code = MBEDTLS_EXIT_FAILURE;
245#if defined(MBEDTLS_ERROR_C)
246    char buf[200];
247#endif
248    int i;
249    char *p, *q;
250
251    const char *pers = "pkey/key_app";
252    mbedtls_entropy_context entropy;
253    mbedtls_ctr_drbg_context ctr_drbg;
254
255    mbedtls_pk_context key;
256#if defined(MBEDTLS_RSA_C)
257    mbedtls_mpi N, P, Q, D, E, DP, DQ, QP;
258#endif /* MBEDTLS_RSA_C */
259
260    /*
261     * Set to sane values
262     */
263    mbedtls_entropy_init(&entropy);
264    mbedtls_ctr_drbg_init(&ctr_drbg);
265
266    mbedtls_pk_init(&key);
267#if defined(MBEDTLS_ERROR_C)
268    memset(buf, 0, sizeof(buf));
269#endif
270
271#if defined(MBEDTLS_USE_PSA_CRYPTO)
272    psa_status_t status = psa_crypto_init();
273    if (status != PSA_SUCCESS) {
274        mbedtls_fprintf(stderr, "Failed to initialize PSA Crypto implementation: %d\n",
275                        (int) status);
276        goto exit;
277    }
278#endif /* MBEDTLS_USE_PSA_CRYPTO */
279
280#if defined(MBEDTLS_RSA_C)
281    mbedtls_mpi_init(&N); mbedtls_mpi_init(&P); mbedtls_mpi_init(&Q);
282    mbedtls_mpi_init(&D); mbedtls_mpi_init(&E); mbedtls_mpi_init(&DP);
283    mbedtls_mpi_init(&DQ); mbedtls_mpi_init(&QP);
284#endif /* MBEDTLS_RSA_C */
285
286    if (argc < 2) {
287usage:
288        mbedtls_printf(USAGE);
289        goto exit;
290    }
291
292    opt.mode                = DFL_MODE;
293    opt.filename            = DFL_FILENAME;
294    opt.output_mode         = DFL_OUTPUT_MODE;
295    opt.output_file         = DFL_OUTPUT_FILENAME;
296    opt.output_format       = DFL_OUTPUT_FORMAT;
297
298    for (i = 1; i < argc; i++) {
299        p = argv[i];
300        if ((q = strchr(p, '=')) == NULL) {
301            goto usage;
302        }
303        *q++ = '\0';
304
305        if (strcmp(p, "mode") == 0) {
306            if (strcmp(q, "private") == 0) {
307                opt.mode = MODE_PRIVATE;
308            } else if (strcmp(q, "public") == 0) {
309                opt.mode = MODE_PUBLIC;
310            } else {
311                goto usage;
312            }
313        } else if (strcmp(p, "output_mode") == 0) {
314            if (strcmp(q, "private") == 0) {
315                opt.output_mode = OUTPUT_MODE_PRIVATE;
316            } else if (strcmp(q, "public") == 0) {
317                opt.output_mode = OUTPUT_MODE_PUBLIC;
318            } else {
319                goto usage;
320            }
321        } else if (strcmp(p, "output_format") == 0) {
322#if defined(MBEDTLS_PEM_WRITE_C)
323            if (strcmp(q, "pem") == 0) {
324                opt.output_format = OUTPUT_FORMAT_PEM;
325            } else
326#endif
327            if (strcmp(q, "der") == 0) {
328                opt.output_format = OUTPUT_FORMAT_DER;
329            } else {
330                goto usage;
331            }
332        } else if (strcmp(p, "filename") == 0) {
333            opt.filename = q;
334        } else if (strcmp(p, "output_file") == 0) {
335            opt.output_file = q;
336        } else {
337            goto usage;
338        }
339    }
340
341    if (opt.mode == MODE_NONE && opt.output_mode != OUTPUT_MODE_NONE) {
342        mbedtls_printf("\nCannot output a key without reading one.\n");
343        goto exit;
344    }
345
346    if (opt.mode == MODE_PUBLIC && opt.output_mode == OUTPUT_MODE_PRIVATE) {
347        mbedtls_printf("\nCannot output a private key from a public key.\n");
348        goto exit;
349    }
350
351    if (opt.mode == MODE_PRIVATE) {
352        /*
353         * 1.1. Load the key
354         */
355        mbedtls_printf("\n  . Loading the private key ...");
356        fflush(stdout);
357
358        if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy,
359                                         (const unsigned char *) pers,
360                                         strlen(pers))) != 0) {
361            mbedtls_printf(" failed\n  !  mbedtls_ctr_drbg_seed returned -0x%04x\n",
362                           (unsigned int) -ret);
363            goto exit;
364        }
365
366        ret = mbedtls_pk_parse_keyfile(&key, opt.filename, NULL,
367                                       mbedtls_ctr_drbg_random, &ctr_drbg);
368        if (ret != 0) {
369            mbedtls_printf(" failed\n  !  mbedtls_pk_parse_keyfile returned -0x%04x",
370                           (unsigned int) -ret);
371            goto exit;
372        }
373
374        mbedtls_printf(" ok\n");
375
376        /*
377         * 1.2 Print the key
378         */
379        mbedtls_printf("  . Key information    ...\n");
380
381#if defined(MBEDTLS_RSA_C)
382        if (mbedtls_pk_get_type(&key) == MBEDTLS_PK_RSA) {
383            mbedtls_rsa_context *rsa = mbedtls_pk_rsa(key);
384
385            if ((ret = mbedtls_rsa_export(rsa, &N, &P, &Q, &D, &E)) != 0 ||
386                (ret = mbedtls_rsa_export_crt(rsa, &DP, &DQ, &QP))      != 0) {
387                mbedtls_printf(" failed\n  ! could not export RSA parameters\n\n");
388                goto exit;
389            }
390
391            mbedtls_mpi_write_file("N:  ",  &N,  16, NULL);
392            mbedtls_mpi_write_file("E:  ",  &E,  16, NULL);
393            mbedtls_mpi_write_file("D:  ",  &D,  16, NULL);
394            mbedtls_mpi_write_file("P:  ",  &P,  16, NULL);
395            mbedtls_mpi_write_file("Q:  ",  &Q,  16, NULL);
396            mbedtls_mpi_write_file("DP: ",  &DP, 16, NULL);
397            mbedtls_mpi_write_file("DQ:  ", &DQ, 16, NULL);
398            mbedtls_mpi_write_file("QP:  ", &QP, 16, NULL);
399        } else
400#endif
401#if defined(MBEDTLS_ECP_C)
402        if (mbedtls_pk_get_type(&key) == MBEDTLS_PK_ECKEY) {
403            if (show_ecp_key(mbedtls_pk_ec(key), 1) != 0) {
404                mbedtls_printf(" failed\n  ! could not export ECC parameters\n\n");
405                goto exit;
406            }
407        } else
408#endif
409        mbedtls_printf("key type not supported yet\n");
410
411    } else if (opt.mode == MODE_PUBLIC) {
412        /*
413         * 1.1. Load the key
414         */
415        mbedtls_printf("\n  . Loading the public key ...");
416        fflush(stdout);
417
418        ret = mbedtls_pk_parse_public_keyfile(&key, opt.filename);
419
420        if (ret != 0) {
421            mbedtls_printf(" failed\n  !  mbedtls_pk_parse_public_key returned -0x%04x",
422                           (unsigned int) -ret);
423            goto exit;
424        }
425
426        mbedtls_printf(" ok\n");
427
428        /*
429         * 1.2 Print the key
430         */
431        mbedtls_printf("  . Key information    ...\n");
432
433#if defined(MBEDTLS_RSA_C)
434        if (mbedtls_pk_get_type(&key) == MBEDTLS_PK_RSA) {
435            mbedtls_rsa_context *rsa = mbedtls_pk_rsa(key);
436
437            if ((ret = mbedtls_rsa_export(rsa, &N, NULL, NULL,
438                                          NULL, &E)) != 0) {
439                mbedtls_printf(" failed\n  ! could not export RSA parameters\n\n");
440                goto exit;
441            }
442            mbedtls_mpi_write_file("N: ", &N, 16, NULL);
443            mbedtls_mpi_write_file("E: ", &E, 16, NULL);
444        } else
445#endif
446#if defined(MBEDTLS_ECP_C)
447        if (mbedtls_pk_get_type(&key) == MBEDTLS_PK_ECKEY) {
448            if (show_ecp_key(mbedtls_pk_ec(key), 0) != 0) {
449                mbedtls_printf(" failed\n  ! could not export ECC parameters\n\n");
450                goto exit;
451            }
452        } else
453#endif
454        mbedtls_printf("key type not supported yet\n");
455    } else {
456        goto usage;
457    }
458
459    if (opt.output_mode == OUTPUT_MODE_PUBLIC) {
460        write_public_key(&key, opt.output_file);
461    }
462    if (opt.output_mode == OUTPUT_MODE_PRIVATE) {
463        write_private_key(&key, opt.output_file);
464    }
465
466    exit_code = MBEDTLS_EXIT_SUCCESS;
467
468exit:
469
470    if (exit_code != MBEDTLS_EXIT_SUCCESS) {
471#ifdef MBEDTLS_ERROR_C
472        mbedtls_strerror(ret, buf, sizeof(buf));
473        mbedtls_printf(" - %s\n", buf);
474#else
475        mbedtls_printf("\n");
476#endif
477    }
478
479#if defined(MBEDTLS_RSA_C)
480    mbedtls_mpi_free(&N); mbedtls_mpi_free(&P); mbedtls_mpi_free(&Q);
481    mbedtls_mpi_free(&D); mbedtls_mpi_free(&E); mbedtls_mpi_free(&DP);
482    mbedtls_mpi_free(&DQ); mbedtls_mpi_free(&QP);
483#endif /* MBEDTLS_RSA_C */
484
485    mbedtls_pk_free(&key);
486
487    mbedtls_ctr_drbg_free(&ctr_drbg);
488    mbedtls_entropy_free(&entropy);
489#if defined(MBEDTLS_USE_PSA_CRYPTO)
490    mbedtls_psa_crypto_free();
491#endif /* MBEDTLS_USE_PSA_CRYPTO */
492
493    mbedtls_exit(exit_code);
494}
495#endif /* program viability conditions */
496