1/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
2 * project 2000.
3 */
4/* ====================================================================
5 * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in
16 *    the documentation and/or other materials provided with the
17 *    distribution.
18 *
19 * 3. All advertising materials mentioning features or use of this
20 *    software must display the following acknowledgment:
21 *    "This product includes software developed by the OpenSSL Project
22 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
23 *
24 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
25 *    endorse or promote products derived from this software without
26 *    prior written permission. For written permission, please contact
27 *    licensing@OpenSSL.org.
28 *
29 * 5. Products derived from this software may not be called "OpenSSL"
30 *    nor may "OpenSSL" appear in their names without prior written
31 *    permission of the OpenSSL Project.
32 *
33 * 6. Redistributions of any form whatsoever must retain the following
34 *    acknowledgment:
35 *    "This product includes software developed by the OpenSSL Project
36 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
37 *
38 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
39 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
41 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
42 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
47 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
48 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
49 * OF THE POSSIBILITY OF SUCH DAMAGE.
50 * ====================================================================
51 *
52 * This product includes cryptographic software written by Eric Young
53 * (eay@cryptsoft.com).  This product includes software written by Tim
54 * Hudson (tjh@cryptsoft.com). */
55
56#include <openssl/rsa.h>
57
58#include <assert.h>
59#include <limits.h>
60#include <string.h>
61
62#include <openssl/bn.h>
63#include <openssl/bytestring.h>
64#include <openssl/err.h>
65#include <openssl/mem.h>
66
67#include "internal.h"
68#include "../bytestring/internal.h"
69#include "../internal.h"
70
71
72static int parse_integer_buggy(CBS *cbs, BIGNUM **out, int buggy) {
73  assert(*out == NULL);
74  *out = BN_new();
75  if (*out == NULL) {
76    return 0;
77  }
78  if (buggy) {
79    return BN_parse_asn1_unsigned_buggy(cbs, *out);
80  }
81  return BN_parse_asn1_unsigned(cbs, *out);
82}
83
84static int parse_integer(CBS *cbs, BIGNUM **out) {
85  return parse_integer_buggy(cbs, out, 0 /* not buggy */);
86}
87
88static int marshal_integer(CBB *cbb, BIGNUM *bn) {
89  if (bn == NULL) {
90    /* An RSA object may be missing some components. */
91    OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING);
92    return 0;
93  }
94  return BN_marshal_asn1(cbb, bn);
95}
96
97static RSA *parse_public_key(CBS *cbs, int buggy) {
98  RSA *ret = RSA_new();
99  if (ret == NULL) {
100    return NULL;
101  }
102  CBS child;
103  if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
104      !parse_integer_buggy(&child, &ret->n, buggy) ||
105      !parse_integer(&child, &ret->e) ||
106      CBS_len(&child) != 0) {
107    OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_ENCODING);
108    RSA_free(ret);
109    return NULL;
110  }
111
112  if (!BN_is_odd(ret->e) ||
113      BN_num_bits(ret->e) < 2) {
114    OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_RSA_PARAMETERS);
115    RSA_free(ret);
116    return NULL;
117  }
118
119  return ret;
120}
121
122RSA *RSA_parse_public_key(CBS *cbs) {
123  return parse_public_key(cbs, 0 /* not buggy */);
124}
125
126RSA *RSA_parse_public_key_buggy(CBS *cbs) {
127  /* Estonian IDs issued between September 2014 to September 2015 are
128   * broken. See https://crbug.com/532048 and https://crbug.com/534766.
129   *
130   * TODO(davidben): Remove this code and callers in March 2016. */
131  return parse_public_key(cbs, 1 /* buggy */);
132}
133
134RSA *RSA_public_key_from_bytes(const uint8_t *in, size_t in_len) {
135  CBS cbs;
136  CBS_init(&cbs, in, in_len);
137  RSA *ret = RSA_parse_public_key(&cbs);
138  if (ret == NULL || CBS_len(&cbs) != 0) {
139    OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_ENCODING);
140    RSA_free(ret);
141    return NULL;
142  }
143  return ret;
144}
145
146int RSA_marshal_public_key(CBB *cbb, const RSA *rsa) {
147  CBB child;
148  if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
149      !marshal_integer(&child, rsa->n) ||
150      !marshal_integer(&child, rsa->e) ||
151      !CBB_flush(cbb)) {
152    OPENSSL_PUT_ERROR(RSA, RSA_R_ENCODE_ERROR);
153    return 0;
154  }
155  return 1;
156}
157
158int RSA_public_key_to_bytes(uint8_t **out_bytes, size_t *out_len,
159                            const RSA *rsa) {
160  CBB cbb;
161  CBB_zero(&cbb);
162  if (!CBB_init(&cbb, 0) ||
163      !RSA_marshal_public_key(&cbb, rsa) ||
164      !CBB_finish(&cbb, out_bytes, out_len)) {
165    OPENSSL_PUT_ERROR(RSA, RSA_R_ENCODE_ERROR);
166    CBB_cleanup(&cbb);
167    return 0;
168  }
169  return 1;
170}
171
172/* kVersionTwoPrime and kVersionMulti are the supported values of the version
173 * field of an RSAPrivateKey structure (RFC 3447). */
174static const uint64_t kVersionTwoPrime = 0;
175static const uint64_t kVersionMulti = 1;
176
177/* rsa_parse_additional_prime parses a DER-encoded OtherPrimeInfo from |cbs| and
178 * advances |cbs|. It returns a newly-allocated |RSA_additional_prime| on
179 * success or NULL on error. The |r| and |mont| fields of the result are set to
180 * NULL. */
181static RSA_additional_prime *rsa_parse_additional_prime(CBS *cbs) {
182  RSA_additional_prime *ret = OPENSSL_malloc(sizeof(RSA_additional_prime));
183  if (ret == NULL) {
184    OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
185    return 0;
186  }
187  OPENSSL_memset(ret, 0, sizeof(RSA_additional_prime));
188
189  CBS child;
190  if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
191      !parse_integer(&child, &ret->prime) ||
192      !parse_integer(&child, &ret->exp) ||
193      !parse_integer(&child, &ret->coeff) ||
194      CBS_len(&child) != 0) {
195    OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_ENCODING);
196    RSA_additional_prime_free(ret);
197    return NULL;
198  }
199
200  return ret;
201}
202
203RSA *RSA_parse_private_key(CBS *cbs) {
204  BN_CTX *ctx = NULL;
205  BIGNUM *product_of_primes_so_far = NULL;
206  RSA *ret = RSA_new();
207  if (ret == NULL) {
208    return NULL;
209  }
210
211  CBS child;
212  uint64_t version;
213  if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
214      !CBS_get_asn1_uint64(&child, &version)) {
215    OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_ENCODING);
216    goto err;
217  }
218
219  if (version != kVersionTwoPrime && version != kVersionMulti) {
220    OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_VERSION);
221    goto err;
222  }
223
224  if (!parse_integer(&child, &ret->n) ||
225      !parse_integer(&child, &ret->e) ||
226      !parse_integer(&child, &ret->d) ||
227      !parse_integer(&child, &ret->p) ||
228      !parse_integer(&child, &ret->q) ||
229      !parse_integer(&child, &ret->dmp1) ||
230      !parse_integer(&child, &ret->dmq1) ||
231      !parse_integer(&child, &ret->iqmp)) {
232    goto err;
233  }
234
235  if (version == kVersionMulti) {
236    /* Although otherPrimeInfos is written as OPTIONAL in RFC 3447, it later
237     * says "[otherPrimeInfos] shall be omitted if version is 0 and shall
238     * contain at least one instance of OtherPrimeInfo if version is 1." The
239     * OPTIONAL is just so both versions share a single definition. */
240    CBS other_prime_infos;
241    if (!CBS_get_asn1(&child, &other_prime_infos, CBS_ASN1_SEQUENCE) ||
242        CBS_len(&other_prime_infos) == 0) {
243      OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_ENCODING);
244      goto err;
245    }
246    ret->additional_primes = sk_RSA_additional_prime_new_null();
247    if (ret->additional_primes == NULL) {
248      OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
249      goto err;
250    }
251
252    ctx = BN_CTX_new();
253    product_of_primes_so_far = BN_new();
254    if (ctx == NULL ||
255        product_of_primes_so_far == NULL ||
256        !BN_mul(product_of_primes_so_far, ret->p, ret->q, ctx)) {
257      goto err;
258    }
259
260    while (CBS_len(&other_prime_infos) > 0) {
261      RSA_additional_prime *ap = rsa_parse_additional_prime(&other_prime_infos);
262      if (ap == NULL) {
263        goto err;
264      }
265      if (!sk_RSA_additional_prime_push(ret->additional_primes, ap)) {
266        OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
267        RSA_additional_prime_free(ap);
268        goto err;
269      }
270      ap->r = BN_dup(product_of_primes_so_far);
271      if (ap->r == NULL ||
272          !BN_mul(product_of_primes_so_far, product_of_primes_so_far,
273                  ap->prime, ctx)) {
274        goto err;
275      }
276    }
277  }
278
279  if (CBS_len(&child) != 0) {
280    OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_ENCODING);
281    goto err;
282  }
283
284  if (!RSA_check_key(ret)) {
285    OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_RSA_PARAMETERS);
286    goto err;
287  }
288
289  BN_CTX_free(ctx);
290  BN_free(product_of_primes_so_far);
291  return ret;
292
293err:
294  BN_CTX_free(ctx);
295  BN_free(product_of_primes_so_far);
296  RSA_free(ret);
297  return NULL;
298}
299
300RSA *RSA_private_key_from_bytes(const uint8_t *in, size_t in_len) {
301  CBS cbs;
302  CBS_init(&cbs, in, in_len);
303  RSA *ret = RSA_parse_private_key(&cbs);
304  if (ret == NULL || CBS_len(&cbs) != 0) {
305    OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_ENCODING);
306    RSA_free(ret);
307    return NULL;
308  }
309  return ret;
310}
311
312int RSA_marshal_private_key(CBB *cbb, const RSA *rsa) {
313  const int is_multiprime =
314      sk_RSA_additional_prime_num(rsa->additional_primes) > 0;
315
316  CBB child;
317  if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
318      !CBB_add_asn1_uint64(&child,
319                           is_multiprime ? kVersionMulti : kVersionTwoPrime) ||
320      !marshal_integer(&child, rsa->n) ||
321      !marshal_integer(&child, rsa->e) ||
322      !marshal_integer(&child, rsa->d) ||
323      !marshal_integer(&child, rsa->p) ||
324      !marshal_integer(&child, rsa->q) ||
325      !marshal_integer(&child, rsa->dmp1) ||
326      !marshal_integer(&child, rsa->dmq1) ||
327      !marshal_integer(&child, rsa->iqmp)) {
328    OPENSSL_PUT_ERROR(RSA, RSA_R_ENCODE_ERROR);
329    return 0;
330  }
331
332  CBB other_prime_infos;
333  if (is_multiprime) {
334    if (!CBB_add_asn1(&child, &other_prime_infos, CBS_ASN1_SEQUENCE)) {
335      OPENSSL_PUT_ERROR(RSA, RSA_R_ENCODE_ERROR);
336      return 0;
337    }
338    for (size_t i = 0; i < sk_RSA_additional_prime_num(rsa->additional_primes);
339         i++) {
340      RSA_additional_prime *ap =
341          sk_RSA_additional_prime_value(rsa->additional_primes, i);
342      CBB other_prime_info;
343      if (!CBB_add_asn1(&other_prime_infos, &other_prime_info,
344                        CBS_ASN1_SEQUENCE) ||
345          !marshal_integer(&other_prime_info, ap->prime) ||
346          !marshal_integer(&other_prime_info, ap->exp) ||
347          !marshal_integer(&other_prime_info, ap->coeff) ||
348          !CBB_flush(&other_prime_infos)) {
349        OPENSSL_PUT_ERROR(RSA, RSA_R_ENCODE_ERROR);
350        return 0;
351      }
352    }
353  }
354
355  if (!CBB_flush(cbb)) {
356    OPENSSL_PUT_ERROR(RSA, RSA_R_ENCODE_ERROR);
357    return 0;
358  }
359  return 1;
360}
361
362int RSA_private_key_to_bytes(uint8_t **out_bytes, size_t *out_len,
363                             const RSA *rsa) {
364  CBB cbb;
365  CBB_zero(&cbb);
366  if (!CBB_init(&cbb, 0) ||
367      !RSA_marshal_private_key(&cbb, rsa) ||
368      !CBB_finish(&cbb, out_bytes, out_len)) {
369    OPENSSL_PUT_ERROR(RSA, RSA_R_ENCODE_ERROR);
370    CBB_cleanup(&cbb);
371    return 0;
372  }
373  return 1;
374}
375
376RSA *d2i_RSAPublicKey(RSA **out, const uint8_t **inp, long len) {
377  if (len < 0) {
378    return NULL;
379  }
380  CBS cbs;
381  CBS_init(&cbs, *inp, (size_t)len);
382  RSA *ret = RSA_parse_public_key(&cbs);
383  if (ret == NULL) {
384    return NULL;
385  }
386  if (out != NULL) {
387    RSA_free(*out);
388    *out = ret;
389  }
390  *inp = CBS_data(&cbs);
391  return ret;
392}
393
394int i2d_RSAPublicKey(const RSA *in, uint8_t **outp) {
395  CBB cbb;
396  if (!CBB_init(&cbb, 0) ||
397      !RSA_marshal_public_key(&cbb, in)) {
398    CBB_cleanup(&cbb);
399    return -1;
400  }
401  return CBB_finish_i2d(&cbb, outp);
402}
403
404RSA *d2i_RSAPrivateKey(RSA **out, const uint8_t **inp, long len) {
405  if (len < 0) {
406    return NULL;
407  }
408  CBS cbs;
409  CBS_init(&cbs, *inp, (size_t)len);
410  RSA *ret = RSA_parse_private_key(&cbs);
411  if (ret == NULL) {
412    return NULL;
413  }
414  if (out != NULL) {
415    RSA_free(*out);
416    *out = ret;
417  }
418  *inp = CBS_data(&cbs);
419  return ret;
420}
421
422int i2d_RSAPrivateKey(const RSA *in, uint8_t **outp) {
423  CBB cbb;
424  if (!CBB_init(&cbb, 0) ||
425      !RSA_marshal_private_key(&cbb, in)) {
426    CBB_cleanup(&cbb);
427    return -1;
428  }
429  return CBB_finish_i2d(&cbb, outp);
430}
431
432RSA *RSAPublicKey_dup(const RSA *rsa) {
433  uint8_t *der;
434  size_t der_len;
435  if (!RSA_public_key_to_bytes(&der, &der_len, rsa)) {
436    return NULL;
437  }
438  RSA *ret = RSA_public_key_from_bytes(der, der_len);
439  OPENSSL_free(der);
440  return ret;
441}
442
443RSA *RSAPrivateKey_dup(const RSA *rsa) {
444  uint8_t *der;
445  size_t der_len;
446  if (!RSA_private_key_to_bytes(&der, &der_len, rsa)) {
447    return NULL;
448  }
449  RSA *ret = RSA_private_key_from_bytes(der, der_len);
450  OPENSSL_free(der);
451  return ret;
452}
453