1 /*
2 * Copyright 2006-2024 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 /*
11 * RSA low level APIs are deprecated for public use, but still ok for
12 * internal use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <stdio.h>
17 #include "internal/cryptlib.h"
18 #include <openssl/asn1t.h>
19 #include <openssl/x509.h>
20 #include <openssl/bn.h>
21 #include <openssl/core_names.h>
22 #include <openssl/param_build.h>
23 #include "crypto/asn1.h"
24 #include "crypto/evp.h"
25 #include "crypto/rsa.h"
26 #include "rsa_local.h"
27
28 /* Set any parameters associated with pkey */
rsa_param_encode(const EVP_PKEY * pkey,ASN1_STRING ** pstr,int * pstrtype)29 static int rsa_param_encode(const EVP_PKEY *pkey,
30 ASN1_STRING **pstr, int *pstrtype)
31 {
32 const RSA *rsa = pkey->pkey.rsa;
33
34 *pstr = NULL;
35 /* If RSA it's just NULL type */
36 if (RSA_test_flags(rsa, RSA_FLAG_TYPE_MASK) != RSA_FLAG_TYPE_RSASSAPSS) {
37 *pstrtype = V_ASN1_NULL;
38 return 1;
39 }
40 /* If no PSS parameters we omit parameters entirely */
41 if (rsa->pss == NULL) {
42 *pstrtype = V_ASN1_UNDEF;
43 return 1;
44 }
45 /* Encode PSS parameters */
46 if (ASN1_item_pack(rsa->pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), pstr) == NULL)
47 return 0;
48
49 *pstrtype = V_ASN1_SEQUENCE;
50 return 1;
51 }
52 /* Decode any parameters and set them in RSA structure */
rsa_pub_encode(X509_PUBKEY * pk,const EVP_PKEY * pkey)53 static int rsa_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
54 {
55 unsigned char *penc = NULL;
56 int penclen;
57 ASN1_STRING *str;
58 int strtype;
59
60 if (!rsa_param_encode(pkey, &str, &strtype))
61 return 0;
62 penclen = i2d_RSAPublicKey(pkey->pkey.rsa, &penc);
63 if (penclen <= 0) {
64 ASN1_STRING_free(str);
65 return 0;
66 }
67 if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
68 strtype, str, penc, penclen))
69 return 1;
70
71 OPENSSL_free(penc);
72 ASN1_STRING_free(str);
73 return 0;
74 }
75
rsa_pub_decode(EVP_PKEY * pkey,const X509_PUBKEY * pubkey)76 static int rsa_pub_decode(EVP_PKEY *pkey, const X509_PUBKEY *pubkey)
77 {
78 const unsigned char *p;
79 int pklen;
80 X509_ALGOR *alg;
81 RSA *rsa = NULL;
82
83 if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &alg, pubkey))
84 return 0;
85 if ((rsa = d2i_RSAPublicKey(NULL, &p, pklen)) == NULL)
86 return 0;
87 if (!ossl_rsa_param_decode(rsa, alg)) {
88 RSA_free(rsa);
89 return 0;
90 }
91
92 RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
93 switch (pkey->ameth->pkey_id) {
94 case EVP_PKEY_RSA:
95 RSA_set_flags(rsa, RSA_FLAG_TYPE_RSA);
96 break;
97 case EVP_PKEY_RSA_PSS:
98 RSA_set_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS);
99 break;
100 default:
101 /* Leave the type bits zero */
102 break;
103 }
104
105 if (!EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa)) {
106 RSA_free(rsa);
107 return 0;
108 }
109 return 1;
110 }
111
rsa_pub_cmp(const EVP_PKEY * a,const EVP_PKEY * b)112 static int rsa_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
113 {
114 /*
115 * Don't check the public/private key, this is mostly for smart
116 * cards.
117 */
118 if (((RSA_flags(a->pkey.rsa) & RSA_METHOD_FLAG_NO_CHECK))
119 || (RSA_flags(b->pkey.rsa) & RSA_METHOD_FLAG_NO_CHECK)) {
120 return 1;
121 }
122
123 if (BN_cmp(b->pkey.rsa->n, a->pkey.rsa->n) != 0
124 || BN_cmp(b->pkey.rsa->e, a->pkey.rsa->e) != 0)
125 return 0;
126 return 1;
127 }
128
old_rsa_priv_decode(EVP_PKEY * pkey,const unsigned char ** pder,int derlen)129 static int old_rsa_priv_decode(EVP_PKEY *pkey,
130 const unsigned char **pder, int derlen)
131 {
132 RSA *rsa;
133
134 if ((rsa = d2i_RSAPrivateKey(NULL, pder, derlen)) == NULL)
135 return 0;
136 EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa);
137 return 1;
138 }
139
old_rsa_priv_encode(const EVP_PKEY * pkey,unsigned char ** pder)140 static int old_rsa_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
141 {
142 return i2d_RSAPrivateKey(pkey->pkey.rsa, pder);
143 }
144
rsa_priv_encode(PKCS8_PRIV_KEY_INFO * p8,const EVP_PKEY * pkey)145 static int rsa_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
146 {
147 unsigned char *rk = NULL;
148 int rklen;
149 ASN1_STRING *str;
150 int strtype;
151
152 if (!rsa_param_encode(pkey, &str, &strtype))
153 return 0;
154 rklen = i2d_RSAPrivateKey(pkey->pkey.rsa, &rk);
155
156 if (rklen <= 0) {
157 ERR_raise(ERR_LIB_RSA, ERR_R_ASN1_LIB);
158 ASN1_STRING_free(str);
159 return 0;
160 }
161
162 if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
163 strtype, str, rk, rklen)) {
164 ERR_raise(ERR_LIB_RSA, ERR_R_ASN1_LIB);
165 ASN1_STRING_free(str);
166 OPENSSL_clear_free(rk, rklen);
167 return 0;
168 }
169
170 return 1;
171 }
172
rsa_priv_decode(EVP_PKEY * pkey,const PKCS8_PRIV_KEY_INFO * p8)173 static int rsa_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
174 {
175 int ret = 0;
176 RSA *rsa = ossl_rsa_key_from_pkcs8(p8, NULL, NULL);
177
178 if (rsa != NULL) {
179 ret = 1;
180 EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa);
181 }
182 return ret;
183 }
184
int_rsa_size(const EVP_PKEY * pkey)185 static int int_rsa_size(const EVP_PKEY *pkey)
186 {
187 return RSA_size(pkey->pkey.rsa);
188 }
189
rsa_bits(const EVP_PKEY * pkey)190 static int rsa_bits(const EVP_PKEY *pkey)
191 {
192 return BN_num_bits(pkey->pkey.rsa->n);
193 }
194
rsa_security_bits(const EVP_PKEY * pkey)195 static int rsa_security_bits(const EVP_PKEY *pkey)
196 {
197 return RSA_security_bits(pkey->pkey.rsa);
198 }
199
int_rsa_free(EVP_PKEY * pkey)200 static void int_rsa_free(EVP_PKEY *pkey)
201 {
202 RSA_free(pkey->pkey.rsa);
203 }
204
rsa_pss_param_print(BIO * bp,int pss_key,RSA_PSS_PARAMS * pss,int indent)205 static int rsa_pss_param_print(BIO *bp, int pss_key, RSA_PSS_PARAMS *pss,
206 int indent)
207 {
208 int rv = 0;
209 X509_ALGOR *maskHash = NULL;
210
211 if (!BIO_indent(bp, indent, 128))
212 goto err;
213 if (pss_key) {
214 if (pss == NULL) {
215 if (BIO_puts(bp, "No PSS parameter restrictions\n") <= 0)
216 return 0;
217 return 1;
218 } else {
219 if (BIO_puts(bp, "PSS parameter restrictions:") <= 0)
220 return 0;
221 }
222 } else if (pss == NULL) {
223 if (BIO_puts(bp, "(INVALID PSS PARAMETERS)\n") <= 0)
224 return 0;
225 return 1;
226 }
227 if (BIO_puts(bp, "\n") <= 0)
228 goto err;
229 if (pss_key)
230 indent += 2;
231 if (!BIO_indent(bp, indent, 128))
232 goto err;
233 if (BIO_puts(bp, "Hash Algorithm: ") <= 0)
234 goto err;
235
236 if (pss->hashAlgorithm) {
237 if (i2a_ASN1_OBJECT(bp, pss->hashAlgorithm->algorithm) <= 0)
238 goto err;
239 } else if (BIO_puts(bp, "sha1 (default)") <= 0) {
240 goto err;
241 }
242
243 if (BIO_puts(bp, "\n") <= 0)
244 goto err;
245
246 if (!BIO_indent(bp, indent, 128))
247 goto err;
248
249 if (BIO_puts(bp, "Mask Algorithm: ") <= 0)
250 goto err;
251 if (pss->maskGenAlgorithm) {
252 if (i2a_ASN1_OBJECT(bp, pss->maskGenAlgorithm->algorithm) <= 0)
253 goto err;
254 if (BIO_puts(bp, " with ") <= 0)
255 goto err;
256 maskHash = ossl_x509_algor_mgf1_decode(pss->maskGenAlgorithm);
257 if (maskHash != NULL) {
258 if (i2a_ASN1_OBJECT(bp, maskHash->algorithm) <= 0)
259 goto err;
260 } else if (BIO_puts(bp, "INVALID") <= 0) {
261 goto err;
262 }
263 } else if (BIO_puts(bp, "mgf1 with sha1 (default)") <= 0) {
264 goto err;
265 }
266 BIO_puts(bp, "\n");
267
268 if (!BIO_indent(bp, indent, 128))
269 goto err;
270 if (BIO_printf(bp, "%s Salt Length: 0x", pss_key ? "Minimum" : "") <= 0)
271 goto err;
272 if (pss->saltLength) {
273 if (i2a_ASN1_INTEGER(bp, pss->saltLength) <= 0)
274 goto err;
275 } else if (BIO_puts(bp, "14 (default)") <= 0) {
276 goto err;
277 }
278 BIO_puts(bp, "\n");
279
280 if (!BIO_indent(bp, indent, 128))
281 goto err;
282 if (BIO_puts(bp, "Trailer Field: 0x") <= 0)
283 goto err;
284 if (pss->trailerField) {
285 if (i2a_ASN1_INTEGER(bp, pss->trailerField) <= 0)
286 goto err;
287 } else if (BIO_puts(bp, "01 (default)") <= 0) {
288 goto err;
289 }
290 BIO_puts(bp, "\n");
291
292 rv = 1;
293
294 err:
295 X509_ALGOR_free(maskHash);
296 return rv;
297
298 }
299
pkey_rsa_print(BIO * bp,const EVP_PKEY * pkey,int off,int priv)300 static int pkey_rsa_print(BIO *bp, const EVP_PKEY *pkey, int off, int priv)
301 {
302 const RSA *x = pkey->pkey.rsa;
303 char *str;
304 const char *s;
305 int ret = 0, mod_len = 0, ex_primes;
306
307 if (x->n != NULL)
308 mod_len = BN_num_bits(x->n);
309 ex_primes = sk_RSA_PRIME_INFO_num(x->prime_infos);
310
311 if (!BIO_indent(bp, off, 128))
312 goto err;
313
314 if (BIO_printf(bp, "%s ", pkey_is_pss(pkey) ? "RSA-PSS" : "RSA") <= 0)
315 goto err;
316
317 if (priv && x->d) {
318 if (BIO_printf(bp, "Private-Key: (%d bit, %d primes)\n",
319 mod_len, ex_primes <= 0 ? 2 : ex_primes + 2) <= 0)
320 goto err;
321 str = "modulus:";
322 s = "publicExponent:";
323 } else {
324 if (BIO_printf(bp, "Public-Key: (%d bit)\n", mod_len) <= 0)
325 goto err;
326 str = "Modulus:";
327 s = "Exponent:";
328 }
329 if (!ASN1_bn_print(bp, str, x->n, NULL, off))
330 goto err;
331 if (!ASN1_bn_print(bp, s, x->e, NULL, off))
332 goto err;
333 if (priv) {
334 int i;
335
336 if (!ASN1_bn_print(bp, "privateExponent:", x->d, NULL, off))
337 goto err;
338 if (!ASN1_bn_print(bp, "prime1:", x->p, NULL, off))
339 goto err;
340 if (!ASN1_bn_print(bp, "prime2:", x->q, NULL, off))
341 goto err;
342 if (!ASN1_bn_print(bp, "exponent1:", x->dmp1, NULL, off))
343 goto err;
344 if (!ASN1_bn_print(bp, "exponent2:", x->dmq1, NULL, off))
345 goto err;
346 if (!ASN1_bn_print(bp, "coefficient:", x->iqmp, NULL, off))
347 goto err;
348 for (i = 0; i < sk_RSA_PRIME_INFO_num(x->prime_infos); i++) {
349 /* print multi-prime info */
350 BIGNUM *bn = NULL;
351 RSA_PRIME_INFO *pinfo;
352 int j;
353
354 pinfo = sk_RSA_PRIME_INFO_value(x->prime_infos, i);
355 for (j = 0; j < 3; j++) {
356 if (!BIO_indent(bp, off, 128))
357 goto err;
358 switch (j) {
359 case 0:
360 if (BIO_printf(bp, "prime%d:", i + 3) <= 0)
361 goto err;
362 bn = pinfo->r;
363 break;
364 case 1:
365 if (BIO_printf(bp, "exponent%d:", i + 3) <= 0)
366 goto err;
367 bn = pinfo->d;
368 break;
369 case 2:
370 if (BIO_printf(bp, "coefficient%d:", i + 3) <= 0)
371 goto err;
372 bn = pinfo->t;
373 break;
374 default:
375 break;
376 }
377 if (!ASN1_bn_print(bp, "", bn, NULL, off))
378 goto err;
379 }
380 }
381 }
382 if (pkey_is_pss(pkey) && !rsa_pss_param_print(bp, 1, x->pss, off))
383 goto err;
384 ret = 1;
385 err:
386 return ret;
387 }
388
rsa_pub_print(BIO * bp,const EVP_PKEY * pkey,int indent,ASN1_PCTX * ctx)389 static int rsa_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
390 ASN1_PCTX *ctx)
391 {
392 return pkey_rsa_print(bp, pkey, indent, 0);
393 }
394
rsa_priv_print(BIO * bp,const EVP_PKEY * pkey,int indent,ASN1_PCTX * ctx)395 static int rsa_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
396 ASN1_PCTX *ctx)
397 {
398 return pkey_rsa_print(bp, pkey, indent, 1);
399 }
400
rsa_sig_print(BIO * bp,const X509_ALGOR * sigalg,const ASN1_STRING * sig,int indent,ASN1_PCTX * pctx)401 static int rsa_sig_print(BIO *bp, const X509_ALGOR *sigalg,
402 const ASN1_STRING *sig, int indent, ASN1_PCTX *pctx)
403 {
404 if (OBJ_obj2nid(sigalg->algorithm) == EVP_PKEY_RSA_PSS) {
405 int rv;
406 RSA_PSS_PARAMS *pss = ossl_rsa_pss_decode(sigalg);
407
408 rv = rsa_pss_param_print(bp, 0, pss, indent);
409 RSA_PSS_PARAMS_free(pss);
410 if (!rv)
411 return 0;
412 } else if (BIO_puts(bp, "\n") <= 0) {
413 return 0;
414 }
415 if (sig)
416 return X509_signature_dump(bp, sig, indent);
417 return 1;
418 }
419
rsa_pkey_ctrl(EVP_PKEY * pkey,int op,long arg1,void * arg2)420 static int rsa_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
421 {
422 const EVP_MD *md;
423 const EVP_MD *mgf1md;
424 int min_saltlen;
425
426 switch (op) {
427 case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
428 if (pkey->pkey.rsa->pss != NULL) {
429 if (!ossl_rsa_pss_get_param(pkey->pkey.rsa->pss, &md, &mgf1md,
430 &min_saltlen)) {
431 ERR_raise(ERR_LIB_RSA, ERR_R_INTERNAL_ERROR);
432 return 0;
433 }
434 *(int *)arg2 = EVP_MD_get_type(md);
435 /* Return of 2 indicates this MD is mandatory */
436 return 2;
437 }
438 *(int *)arg2 = NID_sha256;
439 return 1;
440
441 default:
442 return -2;
443 }
444 }
445
446 /*
447 * Convert EVP_PKEY_CTX in PSS mode into corresponding algorithm parameter,
448 * suitable for setting an AlgorithmIdentifier.
449 */
450
rsa_ctx_to_pss(EVP_PKEY_CTX * pkctx)451 static RSA_PSS_PARAMS *rsa_ctx_to_pss(EVP_PKEY_CTX *pkctx)
452 {
453 const EVP_MD *sigmd, *mgf1md;
454 EVP_PKEY *pk = EVP_PKEY_CTX_get0_pkey(pkctx);
455 int saltlen;
456 int saltlenMax = -1;
457 int md_size;
458
459 if (EVP_PKEY_CTX_get_signature_md(pkctx, &sigmd) <= 0)
460 return NULL;
461 md_size = EVP_MD_get_size(sigmd);
462 if (md_size <= 0)
463 return NULL;
464 if (EVP_PKEY_CTX_get_rsa_mgf1_md(pkctx, &mgf1md) <= 0)
465 return NULL;
466 if (EVP_PKEY_CTX_get_rsa_pss_saltlen(pkctx, &saltlen) <= 0)
467 return NULL;
468 if (saltlen == RSA_PSS_SALTLEN_DIGEST) {
469 saltlen = md_size;
470 } else if (saltlen == RSA_PSS_SALTLEN_AUTO_DIGEST_MAX) {
471 /* FIPS 186-4 section 5 "The RSA Digital Signature Algorithm",
472 * subsection 5.5 "PKCS #1" says: "For RSASSA-PSS […] the length (in
473 * bytes) of the salt (sLen) shall satisfy 0 <= sLen <= hLen, where
474 * hLen is the length of the hash function output block (in bytes)."
475 *
476 * Provide a way to use at most the digest length, so that the default
477 * does not violate FIPS 186-4. */
478 saltlen = RSA_PSS_SALTLEN_MAX;
479 saltlenMax = md_size;
480 }
481 if (saltlen == RSA_PSS_SALTLEN_MAX || saltlen == RSA_PSS_SALTLEN_AUTO) {
482 saltlen = EVP_PKEY_get_size(pk) - md_size - 2;
483 if ((EVP_PKEY_get_bits(pk) & 0x7) == 1)
484 saltlen--;
485 if (saltlen < 0)
486 return NULL;
487 if (saltlenMax >= 0 && saltlen > saltlenMax)
488 saltlen = saltlenMax;
489 }
490
491 return ossl_rsa_pss_params_create(sigmd, mgf1md, saltlen);
492 }
493
ossl_rsa_pss_params_create(const EVP_MD * sigmd,const EVP_MD * mgf1md,int saltlen)494 RSA_PSS_PARAMS *ossl_rsa_pss_params_create(const EVP_MD *sigmd,
495 const EVP_MD *mgf1md, int saltlen)
496 {
497 RSA_PSS_PARAMS *pss = RSA_PSS_PARAMS_new();
498
499 if (pss == NULL)
500 goto err;
501 if (saltlen != 20) {
502 pss->saltLength = ASN1_INTEGER_new();
503 if (pss->saltLength == NULL)
504 goto err;
505 if (!ASN1_INTEGER_set(pss->saltLength, saltlen))
506 goto err;
507 }
508 if (!ossl_x509_algor_new_from_md(&pss->hashAlgorithm, sigmd))
509 goto err;
510 if (mgf1md == NULL)
511 mgf1md = sigmd;
512 if (!ossl_x509_algor_md_to_mgf1(&pss->maskGenAlgorithm, mgf1md))
513 goto err;
514 if (!ossl_x509_algor_new_from_md(&pss->maskHash, mgf1md))
515 goto err;
516 return pss;
517 err:
518 RSA_PSS_PARAMS_free(pss);
519 return NULL;
520 }
521
ossl_rsa_ctx_to_pss_string(EVP_PKEY_CTX * pkctx)522 ASN1_STRING *ossl_rsa_ctx_to_pss_string(EVP_PKEY_CTX *pkctx)
523 {
524 RSA_PSS_PARAMS *pss = rsa_ctx_to_pss(pkctx);
525 ASN1_STRING *os;
526
527 if (pss == NULL)
528 return NULL;
529
530 os = ASN1_item_pack(pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), NULL);
531 RSA_PSS_PARAMS_free(pss);
532 return os;
533 }
534
535 /*
536 * From PSS AlgorithmIdentifier set public key parameters. If pkey isn't NULL
537 * then the EVP_MD_CTX is setup and initialised. If it is NULL parameters are
538 * passed to pkctx instead.
539 */
540
ossl_rsa_pss_to_ctx(EVP_MD_CTX * ctx,EVP_PKEY_CTX * pkctx,const X509_ALGOR * sigalg,EVP_PKEY * pkey)541 int ossl_rsa_pss_to_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pkctx,
542 const X509_ALGOR *sigalg, EVP_PKEY *pkey)
543 {
544 int rv = -1;
545 int saltlen;
546 const EVP_MD *mgf1md = NULL, *md = NULL;
547 RSA_PSS_PARAMS *pss;
548
549 /* Sanity check: make sure it is PSS */
550 if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS) {
551 ERR_raise(ERR_LIB_RSA, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
552 return -1;
553 }
554 /* Decode PSS parameters */
555 pss = ossl_rsa_pss_decode(sigalg);
556
557 if (!ossl_rsa_pss_get_param(pss, &md, &mgf1md, &saltlen)) {
558 ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_PSS_PARAMETERS);
559 goto err;
560 }
561
562 /* We have all parameters now set up context */
563 if (pkey) {
564 if (!EVP_DigestVerifyInit(ctx, &pkctx, md, NULL, pkey))
565 goto err;
566 } else {
567 const EVP_MD *checkmd;
568 if (EVP_PKEY_CTX_get_signature_md(pkctx, &checkmd) <= 0)
569 goto err;
570 if (EVP_MD_get_type(md) != EVP_MD_get_type(checkmd)) {
571 ERR_raise(ERR_LIB_RSA, RSA_R_DIGEST_DOES_NOT_MATCH);
572 goto err;
573 }
574 }
575
576 if (EVP_PKEY_CTX_set_rsa_padding(pkctx, RSA_PKCS1_PSS_PADDING) <= 0)
577 goto err;
578
579 if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkctx, saltlen) <= 0)
580 goto err;
581
582 if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkctx, mgf1md) <= 0)
583 goto err;
584 /* Carry on */
585 rv = 1;
586
587 err:
588 RSA_PSS_PARAMS_free(pss);
589 return rv;
590 }
591
rsa_pss_verify_param(const EVP_MD ** pmd,const EVP_MD ** pmgf1md,int * psaltlen,int * ptrailerField)592 static int rsa_pss_verify_param(const EVP_MD **pmd, const EVP_MD **pmgf1md,
593 int *psaltlen, int *ptrailerField)
594 {
595 if (psaltlen != NULL && *psaltlen < 0) {
596 ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_SALT_LENGTH);
597 return 0;
598 }
599 /*
600 * low-level routines support only trailer field 0xbc (value 1) and
601 * PKCS#1 says we should reject any other value anyway.
602 */
603 if (ptrailerField != NULL && *ptrailerField != 1) {
604 ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_TRAILER);
605 return 0;
606 }
607 return 1;
608 }
609
ossl_rsa_pss_get_param(const RSA_PSS_PARAMS * pss,const EVP_MD ** pmd,const EVP_MD ** pmgf1md,int * psaltlen)610 int ossl_rsa_pss_get_param(const RSA_PSS_PARAMS *pss, const EVP_MD **pmd,
611 const EVP_MD **pmgf1md, int *psaltlen)
612 {
613 /*
614 * Callers do not care about the trailer field, and yet, we must
615 * pass it from get_param to verify_param, since the latter checks
616 * its value.
617 *
618 * When callers start caring, it's a simple thing to add another
619 * argument to this function.
620 */
621 int trailerField = 0;
622
623 return ossl_rsa_pss_get_param_unverified(pss, pmd, pmgf1md, psaltlen,
624 &trailerField)
625 && rsa_pss_verify_param(pmd, pmgf1md, psaltlen, &trailerField);
626 }
627
628 /*
629 * Customised RSA item verification routine. This is called when a signature
630 * is encountered requiring special handling. We currently only handle PSS.
631 */
632
rsa_item_verify(EVP_MD_CTX * ctx,const ASN1_ITEM * it,const void * asn,const X509_ALGOR * sigalg,const ASN1_BIT_STRING * sig,EVP_PKEY * pkey)633 static int rsa_item_verify(EVP_MD_CTX *ctx, const ASN1_ITEM *it,
634 const void *asn, const X509_ALGOR *sigalg,
635 const ASN1_BIT_STRING *sig, EVP_PKEY *pkey)
636 {
637 /* Sanity check: make sure it is PSS */
638 if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS) {
639 ERR_raise(ERR_LIB_RSA, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
640 return -1;
641 }
642 if (ossl_rsa_pss_to_ctx(ctx, NULL, sigalg, pkey) > 0) {
643 /* Carry on */
644 return 2;
645 }
646 return -1;
647 }
648
rsa_item_sign(EVP_MD_CTX * ctx,const ASN1_ITEM * it,const void * asn,X509_ALGOR * alg1,X509_ALGOR * alg2,ASN1_BIT_STRING * sig)649 static int rsa_item_sign(EVP_MD_CTX *ctx, const ASN1_ITEM *it, const void *asn,
650 X509_ALGOR *alg1, X509_ALGOR *alg2,
651 ASN1_BIT_STRING *sig)
652 {
653 int pad_mode;
654 EVP_PKEY_CTX *pkctx = EVP_MD_CTX_get_pkey_ctx(ctx);
655
656 if (EVP_PKEY_CTX_get_rsa_padding(pkctx, &pad_mode) <= 0)
657 return 0;
658 if (pad_mode == RSA_PKCS1_PADDING)
659 return 2;
660 if (pad_mode == RSA_PKCS1_PSS_PADDING) {
661 unsigned char aid[128];
662 size_t aid_len = 0;
663 OSSL_PARAM params[2];
664
665 if (evp_pkey_ctx_is_legacy(pkctx)) {
666 /* No provider -> we cannot query it for algorithm ID. */
667 ASN1_STRING *os1 = NULL;
668
669 os1 = ossl_rsa_ctx_to_pss_string(pkctx);
670 if (os1 == NULL)
671 return 0;
672 /* Duplicate parameters if we have to */
673 if (alg2 != NULL) {
674 ASN1_STRING *os2 = ASN1_STRING_dup(os1);
675
676 if (os2 == NULL) {
677 ASN1_STRING_free(os1);
678 return 0;
679 }
680 if (!X509_ALGOR_set0(alg2, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
681 V_ASN1_SEQUENCE, os2)) {
682 ASN1_STRING_free(os1);
683 ASN1_STRING_free(os2);
684 return 0;
685 }
686 }
687 if (!X509_ALGOR_set0(alg1, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
688 V_ASN1_SEQUENCE, os1)) {
689 ASN1_STRING_free(os1);
690 return 0;
691 }
692 return 3;
693 }
694
695 params[0] = OSSL_PARAM_construct_octet_string(
696 OSSL_SIGNATURE_PARAM_ALGORITHM_ID, aid, sizeof(aid));
697 params[1] = OSSL_PARAM_construct_end();
698
699 if (EVP_PKEY_CTX_get_params(pkctx, params) <= 0)
700 return 0;
701 if ((aid_len = params[0].return_size) == 0)
702 return 0;
703
704 if (alg1 != NULL) {
705 const unsigned char *pp = aid;
706
707 if (d2i_X509_ALGOR(&alg1, &pp, aid_len) == NULL)
708 return 0;
709 }
710 if (alg2 != NULL) {
711 const unsigned char *pp = aid;
712
713 if (d2i_X509_ALGOR(&alg2, &pp, aid_len) == NULL)
714 return 0;
715 }
716
717 return 3;
718 }
719 return 2;
720 }
721
rsa_sig_info_set(X509_SIG_INFO * siginf,const X509_ALGOR * sigalg,const ASN1_STRING * sig)722 static int rsa_sig_info_set(X509_SIG_INFO *siginf, const X509_ALGOR *sigalg,
723 const ASN1_STRING *sig)
724 {
725 int rv = 0;
726 int mdnid, saltlen, md_size;
727 uint32_t flags;
728 const EVP_MD *mgf1md = NULL, *md = NULL;
729 RSA_PSS_PARAMS *pss;
730 int secbits;
731
732 /* Sanity check: make sure it is PSS */
733 if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS)
734 return 0;
735 /* Decode PSS parameters */
736 pss = ossl_rsa_pss_decode(sigalg);
737 if (!ossl_rsa_pss_get_param(pss, &md, &mgf1md, &saltlen))
738 goto err;
739 md_size = EVP_MD_get_size(md);
740 if (md_size <= 0)
741 goto err;
742 mdnid = EVP_MD_get_type(md);
743 /*
744 * For TLS need SHA256, SHA384 or SHA512, digest and MGF1 digest must
745 * match and salt length must equal digest size
746 */
747 if ((mdnid == NID_sha256 || mdnid == NID_sha384 || mdnid == NID_sha512)
748 && mdnid == EVP_MD_get_type(mgf1md)
749 && saltlen == md_size)
750 flags = X509_SIG_INFO_TLS;
751 else
752 flags = 0;
753 /* Note: security bits half number of digest bits */
754 secbits = md_size * 4;
755 /*
756 * SHA1 and MD5 are known to be broken. Reduce security bits so that
757 * they're no longer accepted at security level 1. The real values don't
758 * really matter as long as they're lower than 80, which is our security
759 * level 1.
760 * https://eprint.iacr.org/2020/014 puts a chosen-prefix attack for SHA1 at
761 * 2^63.4
762 * https://documents.epfl.ch/users/l/le/lenstra/public/papers/lat.pdf
763 * puts a chosen-prefix attack for MD5 at 2^39.
764 */
765 if (mdnid == NID_sha1)
766 secbits = 64;
767 else if (mdnid == NID_md5_sha1)
768 secbits = 68;
769 else if (mdnid == NID_md5)
770 secbits = 39;
771 X509_SIG_INFO_set(siginf, mdnid, EVP_PKEY_RSA_PSS, secbits,
772 flags);
773 rv = 1;
774 err:
775 RSA_PSS_PARAMS_free(pss);
776 return rv;
777 }
778
rsa_pkey_check(const EVP_PKEY * pkey)779 static int rsa_pkey_check(const EVP_PKEY *pkey)
780 {
781 return RSA_check_key_ex(pkey->pkey.rsa, NULL);
782 }
783
rsa_pkey_dirty_cnt(const EVP_PKEY * pkey)784 static size_t rsa_pkey_dirty_cnt(const EVP_PKEY *pkey)
785 {
786 return pkey->pkey.rsa->dirty_cnt;
787 }
788
789 /*
790 * There is no need to do RSA_test_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS)
791 * checks in this method since the caller tests EVP_KEYMGMT_is_a() first.
792 */
rsa_int_export_to(const EVP_PKEY * from,int rsa_type,void * to_keydata,OSSL_FUNC_keymgmt_import_fn * importer,OSSL_LIB_CTX * libctx,const char * propq)793 static int rsa_int_export_to(const EVP_PKEY *from, int rsa_type,
794 void *to_keydata,
795 OSSL_FUNC_keymgmt_import_fn *importer,
796 OSSL_LIB_CTX *libctx, const char *propq)
797 {
798 RSA *rsa = from->pkey.rsa;
799 OSSL_PARAM_BLD *tmpl = OSSL_PARAM_BLD_new();
800 OSSL_PARAM *params = NULL;
801 int selection = 0;
802 int rv = 0;
803
804 if (tmpl == NULL)
805 return 0;
806 /* Public parameters must always be present */
807 if (RSA_get0_n(rsa) == NULL || RSA_get0_e(rsa) == NULL)
808 goto err;
809
810 if (!ossl_rsa_todata(rsa, tmpl, NULL, 1))
811 goto err;
812
813 selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
814 if (RSA_get0_d(rsa) != NULL)
815 selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
816
817 if (rsa->pss != NULL) {
818 const EVP_MD *md = NULL, *mgf1md = NULL;
819 int md_nid, mgf1md_nid, saltlen, trailerfield;
820 RSA_PSS_PARAMS_30 pss_params;
821
822 if (!ossl_rsa_pss_get_param_unverified(rsa->pss, &md, &mgf1md,
823 &saltlen, &trailerfield))
824 goto err;
825 md_nid = EVP_MD_get_type(md);
826 mgf1md_nid = EVP_MD_get_type(mgf1md);
827 if (!ossl_rsa_pss_params_30_set_defaults(&pss_params)
828 || !ossl_rsa_pss_params_30_set_hashalg(&pss_params, md_nid)
829 || !ossl_rsa_pss_params_30_set_maskgenhashalg(&pss_params,
830 mgf1md_nid)
831 || !ossl_rsa_pss_params_30_set_saltlen(&pss_params, saltlen)
832 || !ossl_rsa_pss_params_30_todata(&pss_params, tmpl, NULL))
833 goto err;
834 selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
835 }
836
837 if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
838 goto err;
839
840 /* We export, the provider imports */
841 rv = importer(to_keydata, selection, params);
842
843 err:
844 OSSL_PARAM_free(params);
845 OSSL_PARAM_BLD_free(tmpl);
846 return rv;
847 }
848
rsa_int_import_from(const OSSL_PARAM params[],void * vpctx,int rsa_type)849 static int rsa_int_import_from(const OSSL_PARAM params[], void *vpctx,
850 int rsa_type)
851 {
852 EVP_PKEY_CTX *pctx = vpctx;
853 EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
854 RSA *rsa = ossl_rsa_new_with_ctx(pctx->libctx);
855 RSA_PSS_PARAMS_30 rsa_pss_params = { 0, };
856 int pss_defaults_set = 0;
857 int ok = 0;
858
859 if (rsa == NULL) {
860 ERR_raise(ERR_LIB_DH, ERR_R_RSA_LIB);
861 return 0;
862 }
863
864 RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
865 RSA_set_flags(rsa, rsa_type);
866
867 if (!ossl_rsa_pss_params_30_fromdata(&rsa_pss_params, &pss_defaults_set,
868 params, pctx->libctx))
869 goto err;
870
871 switch (rsa_type) {
872 case RSA_FLAG_TYPE_RSA:
873 /*
874 * Were PSS parameters filled in?
875 * In that case, something's wrong
876 */
877 if (!ossl_rsa_pss_params_30_is_unrestricted(&rsa_pss_params))
878 goto err;
879 break;
880 case RSA_FLAG_TYPE_RSASSAPSS:
881 /*
882 * Were PSS parameters filled in? In that case, create the old
883 * RSA_PSS_PARAMS structure. Otherwise, this is an unrestricted key.
884 */
885 if (!ossl_rsa_pss_params_30_is_unrestricted(&rsa_pss_params)) {
886 /* Create the older RSA_PSS_PARAMS from RSA_PSS_PARAMS_30 data */
887 int mdnid = ossl_rsa_pss_params_30_hashalg(&rsa_pss_params);
888 int mgf1mdnid = ossl_rsa_pss_params_30_maskgenhashalg(&rsa_pss_params);
889 int saltlen = ossl_rsa_pss_params_30_saltlen(&rsa_pss_params);
890 const EVP_MD *md = EVP_get_digestbynid(mdnid);
891 const EVP_MD *mgf1md = EVP_get_digestbynid(mgf1mdnid);
892
893 if ((rsa->pss = ossl_rsa_pss_params_create(md, mgf1md,
894 saltlen)) == NULL)
895 goto err;
896 }
897 break;
898 default:
899 /* RSA key sub-types we don't know how to handle yet */
900 goto err;
901 }
902
903 if (!ossl_rsa_fromdata(rsa, params, 1))
904 goto err;
905
906 switch (rsa_type) {
907 case RSA_FLAG_TYPE_RSA:
908 ok = EVP_PKEY_assign_RSA(pkey, rsa);
909 break;
910 case RSA_FLAG_TYPE_RSASSAPSS:
911 ok = EVP_PKEY_assign(pkey, EVP_PKEY_RSA_PSS, rsa);
912 break;
913 }
914
915 err:
916 if (!ok)
917 RSA_free(rsa);
918 return ok;
919 }
920
rsa_pkey_export_to(const EVP_PKEY * from,void * to_keydata,OSSL_FUNC_keymgmt_import_fn * importer,OSSL_LIB_CTX * libctx,const char * propq)921 static int rsa_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
922 OSSL_FUNC_keymgmt_import_fn *importer,
923 OSSL_LIB_CTX *libctx, const char *propq)
924 {
925 return rsa_int_export_to(from, RSA_FLAG_TYPE_RSA, to_keydata,
926 importer, libctx, propq);
927 }
928
rsa_pss_pkey_export_to(const EVP_PKEY * from,void * to_keydata,OSSL_FUNC_keymgmt_import_fn * importer,OSSL_LIB_CTX * libctx,const char * propq)929 static int rsa_pss_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
930 OSSL_FUNC_keymgmt_import_fn *importer,
931 OSSL_LIB_CTX *libctx, const char *propq)
932 {
933 return rsa_int_export_to(from, RSA_FLAG_TYPE_RSASSAPSS, to_keydata,
934 importer, libctx, propq);
935 }
936
rsa_pkey_import_from(const OSSL_PARAM params[],void * vpctx)937 static int rsa_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
938 {
939 return rsa_int_import_from(params, vpctx, RSA_FLAG_TYPE_RSA);
940 }
941
rsa_pss_pkey_import_from(const OSSL_PARAM params[],void * vpctx)942 static int rsa_pss_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
943 {
944 return rsa_int_import_from(params, vpctx, RSA_FLAG_TYPE_RSASSAPSS);
945 }
946
rsa_pkey_copy(EVP_PKEY * to,EVP_PKEY * from)947 static int rsa_pkey_copy(EVP_PKEY *to, EVP_PKEY *from)
948 {
949 RSA *rsa = from->pkey.rsa;
950 RSA *dupkey = NULL;
951 int ret;
952
953 if (rsa != NULL) {
954 dupkey = ossl_rsa_dup(rsa, OSSL_KEYMGMT_SELECT_ALL);
955 if (dupkey == NULL)
956 return 0;
957 }
958
959 ret = EVP_PKEY_assign(to, from->type, dupkey);
960 if (!ret)
961 RSA_free(dupkey);
962 return ret;
963 }
964
965 const EVP_PKEY_ASN1_METHOD ossl_rsa_asn1_meths[2] = {
966 {
967 EVP_PKEY_RSA,
968 EVP_PKEY_RSA,
969 ASN1_PKEY_SIGPARAM_NULL,
970
971 "RSA",
972 "OpenSSL RSA method",
973
974 rsa_pub_decode,
975 rsa_pub_encode,
976 rsa_pub_cmp,
977 rsa_pub_print,
978
979 rsa_priv_decode,
980 rsa_priv_encode,
981 rsa_priv_print,
982
983 int_rsa_size,
984 rsa_bits,
985 rsa_security_bits,
986
987 0, 0, 0, 0, 0, 0,
988
989 rsa_sig_print,
990 int_rsa_free,
991 rsa_pkey_ctrl,
992 old_rsa_priv_decode,
993 old_rsa_priv_encode,
994 rsa_item_verify,
995 rsa_item_sign,
996 rsa_sig_info_set,
997 rsa_pkey_check,
998
999 0, 0,
1000 0, 0, 0, 0,
1001
1002 rsa_pkey_dirty_cnt,
1003 rsa_pkey_export_to,
1004 rsa_pkey_import_from,
1005 rsa_pkey_copy
1006 },
1007
1008 {
1009 EVP_PKEY_RSA2,
1010 EVP_PKEY_RSA,
1011 ASN1_PKEY_ALIAS}
1012 };
1013
1014 const EVP_PKEY_ASN1_METHOD ossl_rsa_pss_asn1_meth = {
1015 EVP_PKEY_RSA_PSS,
1016 EVP_PKEY_RSA_PSS,
1017 ASN1_PKEY_SIGPARAM_NULL,
1018
1019 "RSA-PSS",
1020 "OpenSSL RSA-PSS method",
1021
1022 rsa_pub_decode,
1023 rsa_pub_encode,
1024 rsa_pub_cmp,
1025 rsa_pub_print,
1026
1027 rsa_priv_decode,
1028 rsa_priv_encode,
1029 rsa_priv_print,
1030
1031 int_rsa_size,
1032 rsa_bits,
1033 rsa_security_bits,
1034
1035 0, 0, 0, 0, 0, 0,
1036
1037 rsa_sig_print,
1038 int_rsa_free,
1039 rsa_pkey_ctrl,
1040 0, 0,
1041 rsa_item_verify,
1042 rsa_item_sign,
1043 rsa_sig_info_set,
1044 rsa_pkey_check,
1045
1046 0, 0,
1047 0, 0, 0, 0,
1048
1049 rsa_pkey_dirty_cnt,
1050 rsa_pss_pkey_export_to,
1051 rsa_pss_pkey_import_from,
1052 rsa_pkey_copy
1053 };
1054
