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 
parse_integer_buggy(CBS * cbs,BIGNUM ** out,int buggy)72 static 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 
parse_integer(CBS * cbs,BIGNUM ** out)84 static int parse_integer(CBS *cbs, BIGNUM **out) {
85   return parse_integer_buggy(cbs, out, 0 /* not buggy */);
86 }
87 
marshal_integer(CBB * cbb,BIGNUM * bn)88 static 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 
parse_public_key(CBS * cbs,int buggy)97 static 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 
RSA_parse_public_key(CBS * cbs)122 RSA *RSA_parse_public_key(CBS *cbs) {
123   return parse_public_key(cbs, 0 /* not buggy */);
124 }
125 
RSA_parse_public_key_buggy(CBS * cbs)126 RSA *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 
RSA_public_key_from_bytes(const uint8_t * in,size_t in_len)134 RSA *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 
RSA_marshal_public_key(CBB * cbb,const RSA * rsa)146 int 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 
RSA_public_key_to_bytes(uint8_t ** out_bytes,size_t * out_len,const RSA * rsa)158 int 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). */
174 static const uint64_t kVersionTwoPrime = 0;
175 static 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. */
rsa_parse_additional_prime(CBS * cbs)181 static 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 
RSA_parse_private_key(CBS * cbs)203 RSA *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 
293 err:
294   BN_CTX_free(ctx);
295   BN_free(product_of_primes_so_far);
296   RSA_free(ret);
297   return NULL;
298 }
299 
RSA_private_key_from_bytes(const uint8_t * in,size_t in_len)300 RSA *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 
RSA_marshal_private_key(CBB * cbb,const RSA * rsa)312 int 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 
RSA_private_key_to_bytes(uint8_t ** out_bytes,size_t * out_len,const RSA * rsa)362 int 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 
d2i_RSAPublicKey(RSA ** out,const uint8_t ** inp,long len)376 RSA *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 
i2d_RSAPublicKey(const RSA * in,uint8_t ** outp)394 int 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 
d2i_RSAPrivateKey(RSA ** out,const uint8_t ** inp,long len)404 RSA *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 
i2d_RSAPrivateKey(const RSA * in,uint8_t ** outp)422 int 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 
RSAPublicKey_dup(const RSA * rsa)432 RSA *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 
RSAPrivateKey_dup(const RSA * rsa)443 RSA *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