xref: /freebsd/crypto/openssl/crypto/rsa/rsa_ameth.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*
2  * Copyright 2006-2023 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 */
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 */
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 
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 
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 
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 
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 
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_MALLOC_FAILURE);
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_MALLOC_FAILURE);
165         ASN1_STRING_free(str);
166         OPENSSL_clear_free(rk, rklen);
167         return 0;
168     }
169 
170     return 1;
171 }
172 
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 
185 static int int_rsa_size(const EVP_PKEY *pkey)
186 {
187     return RSA_size(pkey->pkey.rsa);
188 }
189 
190 static int rsa_bits(const EVP_PKEY *pkey)
191 {
192     return BN_num_bits(pkey->pkey.rsa->n);
193 }
194 
195 static int rsa_security_bits(const EVP_PKEY *pkey)
196 {
197     return RSA_security_bits(pkey->pkey.rsa);
198 }
199 
200 static void int_rsa_free(EVP_PKEY *pkey)
201 {
202     RSA_free(pkey->pkey.rsa);
203 }
204 
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 
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 
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 
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 
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 
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 
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 
457     if (EVP_PKEY_CTX_get_signature_md(pkctx, &sigmd) <= 0)
458         return NULL;
459     if (EVP_PKEY_CTX_get_rsa_mgf1_md(pkctx, &mgf1md) <= 0)
460         return NULL;
461     if (EVP_PKEY_CTX_get_rsa_pss_saltlen(pkctx, &saltlen) <= 0)
462         return NULL;
463     if (saltlen == -1) {
464         saltlen = EVP_MD_get_size(sigmd);
465     } else if (saltlen == -2 || saltlen == -3) {
466         saltlen = EVP_PKEY_get_size(pk) - EVP_MD_get_size(sigmd) - 2;
467         if ((EVP_PKEY_get_bits(pk) & 0x7) == 1)
468             saltlen--;
469         if (saltlen < 0)
470             return NULL;
471     }
472 
473     return ossl_rsa_pss_params_create(sigmd, mgf1md, saltlen);
474 }
475 
476 RSA_PSS_PARAMS *ossl_rsa_pss_params_create(const EVP_MD *sigmd,
477                                            const EVP_MD *mgf1md, int saltlen)
478 {
479     RSA_PSS_PARAMS *pss = RSA_PSS_PARAMS_new();
480 
481     if (pss == NULL)
482         goto err;
483     if (saltlen != 20) {
484         pss->saltLength = ASN1_INTEGER_new();
485         if (pss->saltLength == NULL)
486             goto err;
487         if (!ASN1_INTEGER_set(pss->saltLength, saltlen))
488             goto err;
489     }
490     if (!ossl_x509_algor_new_from_md(&pss->hashAlgorithm, sigmd))
491         goto err;
492     if (mgf1md == NULL)
493         mgf1md = sigmd;
494     if (!ossl_x509_algor_md_to_mgf1(&pss->maskGenAlgorithm, mgf1md))
495         goto err;
496     if (!ossl_x509_algor_new_from_md(&pss->maskHash, mgf1md))
497         goto err;
498     return pss;
499  err:
500     RSA_PSS_PARAMS_free(pss);
501     return NULL;
502 }
503 
504 ASN1_STRING *ossl_rsa_ctx_to_pss_string(EVP_PKEY_CTX *pkctx)
505 {
506     RSA_PSS_PARAMS *pss = rsa_ctx_to_pss(pkctx);
507     ASN1_STRING *os;
508 
509     if (pss == NULL)
510         return NULL;
511 
512     os = ASN1_item_pack(pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), NULL);
513     RSA_PSS_PARAMS_free(pss);
514     return os;
515 }
516 
517 /*
518  * From PSS AlgorithmIdentifier set public key parameters. If pkey isn't NULL
519  * then the EVP_MD_CTX is setup and initialised. If it is NULL parameters are
520  * passed to pkctx instead.
521  */
522 
523 int ossl_rsa_pss_to_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pkctx,
524                         const X509_ALGOR *sigalg, EVP_PKEY *pkey)
525 {
526     int rv = -1;
527     int saltlen;
528     const EVP_MD *mgf1md = NULL, *md = NULL;
529     RSA_PSS_PARAMS *pss;
530 
531     /* Sanity check: make sure it is PSS */
532     if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS) {
533         ERR_raise(ERR_LIB_RSA, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
534         return -1;
535     }
536     /* Decode PSS parameters */
537     pss = ossl_rsa_pss_decode(sigalg);
538 
539     if (!ossl_rsa_pss_get_param(pss, &md, &mgf1md, &saltlen)) {
540         ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_PSS_PARAMETERS);
541         goto err;
542     }
543 
544     /* We have all parameters now set up context */
545     if (pkey) {
546         if (!EVP_DigestVerifyInit(ctx, &pkctx, md, NULL, pkey))
547             goto err;
548     } else {
549         const EVP_MD *checkmd;
550         if (EVP_PKEY_CTX_get_signature_md(pkctx, &checkmd) <= 0)
551             goto err;
552         if (EVP_MD_get_type(md) != EVP_MD_get_type(checkmd)) {
553             ERR_raise(ERR_LIB_RSA, RSA_R_DIGEST_DOES_NOT_MATCH);
554             goto err;
555         }
556     }
557 
558     if (EVP_PKEY_CTX_set_rsa_padding(pkctx, RSA_PKCS1_PSS_PADDING) <= 0)
559         goto err;
560 
561     if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkctx, saltlen) <= 0)
562         goto err;
563 
564     if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkctx, mgf1md) <= 0)
565         goto err;
566     /* Carry on */
567     rv = 1;
568 
569  err:
570     RSA_PSS_PARAMS_free(pss);
571     return rv;
572 }
573 
574 static int rsa_pss_verify_param(const EVP_MD **pmd, const EVP_MD **pmgf1md,
575                                 int *psaltlen, int *ptrailerField)
576 {
577     if (psaltlen != NULL && *psaltlen < 0) {
578         ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_SALT_LENGTH);
579         return 0;
580     }
581     /*
582      * low-level routines support only trailer field 0xbc (value 1) and
583      * PKCS#1 says we should reject any other value anyway.
584      */
585     if (ptrailerField != NULL && *ptrailerField != 1) {
586         ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_TRAILER);
587         return 0;
588     }
589     return 1;
590 }
591 
592 int ossl_rsa_pss_get_param(const RSA_PSS_PARAMS *pss, const EVP_MD **pmd,
593                            const EVP_MD **pmgf1md, int *psaltlen)
594 {
595     /*
596      * Callers do not care about the trailer field, and yet, we must
597      * pass it from get_param to verify_param, since the latter checks
598      * its value.
599      *
600      * When callers start caring, it's a simple thing to add another
601      * argument to this function.
602      */
603     int trailerField = 0;
604 
605     return ossl_rsa_pss_get_param_unverified(pss, pmd, pmgf1md, psaltlen,
606                                              &trailerField)
607         && rsa_pss_verify_param(pmd, pmgf1md, psaltlen, &trailerField);
608 }
609 
610 /*
611  * Customised RSA item verification routine. This is called when a signature
612  * is encountered requiring special handling. We currently only handle PSS.
613  */
614 
615 static int rsa_item_verify(EVP_MD_CTX *ctx, const ASN1_ITEM *it,
616                            const void *asn, const X509_ALGOR *sigalg,
617                            const ASN1_BIT_STRING *sig, EVP_PKEY *pkey)
618 {
619     /* Sanity check: make sure it is PSS */
620     if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS) {
621         ERR_raise(ERR_LIB_RSA, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
622         return -1;
623     }
624     if (ossl_rsa_pss_to_ctx(ctx, NULL, sigalg, pkey) > 0) {
625         /* Carry on */
626         return 2;
627     }
628     return -1;
629 }
630 
631 static int rsa_item_sign(EVP_MD_CTX *ctx, const ASN1_ITEM *it, const void *asn,
632                          X509_ALGOR *alg1, X509_ALGOR *alg2,
633                          ASN1_BIT_STRING *sig)
634 {
635     int pad_mode;
636     EVP_PKEY_CTX *pkctx = EVP_MD_CTX_get_pkey_ctx(ctx);
637 
638     if (EVP_PKEY_CTX_get_rsa_padding(pkctx, &pad_mode) <= 0)
639         return 0;
640     if (pad_mode == RSA_PKCS1_PADDING)
641         return 2;
642     if (pad_mode == RSA_PKCS1_PSS_PADDING) {
643         unsigned char aid[128];
644         size_t aid_len = 0;
645         OSSL_PARAM params[2];
646 
647         if (evp_pkey_ctx_is_legacy(pkctx)) {
648             /* No provider -> we cannot query it for algorithm ID. */
649             ASN1_STRING *os1 = NULL;
650 
651             os1 = ossl_rsa_ctx_to_pss_string(pkctx);
652             if (os1 == NULL)
653                 return 0;
654             /* Duplicate parameters if we have to */
655             if (alg2 != NULL) {
656                 ASN1_STRING *os2 = ASN1_STRING_dup(os1);
657 
658                 if (os2 == NULL) {
659                     ASN1_STRING_free(os1);
660                     return 0;
661                 }
662                 if (!X509_ALGOR_set0(alg2, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
663                                      V_ASN1_SEQUENCE, os2)) {
664                     ASN1_STRING_free(os1);
665                     ASN1_STRING_free(os2);
666                     return 0;
667                 }
668             }
669             if (!X509_ALGOR_set0(alg1, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
670                                  V_ASN1_SEQUENCE, os1)) {
671                     ASN1_STRING_free(os1);
672                     return 0;
673             }
674             return 3;
675         }
676 
677         params[0] = OSSL_PARAM_construct_octet_string(
678             OSSL_SIGNATURE_PARAM_ALGORITHM_ID, aid, sizeof(aid));
679         params[1] = OSSL_PARAM_construct_end();
680 
681         if (EVP_PKEY_CTX_get_params(pkctx, params) <= 0)
682             return 0;
683         if ((aid_len = params[0].return_size) == 0)
684             return 0;
685 
686         if (alg1 != NULL) {
687             const unsigned char *pp = aid;
688 
689             if (d2i_X509_ALGOR(&alg1, &pp, aid_len) == NULL)
690                 return 0;
691         }
692         if (alg2 != NULL) {
693             const unsigned char *pp = aid;
694 
695             if (d2i_X509_ALGOR(&alg2, &pp, aid_len) == NULL)
696                 return 0;
697         }
698 
699         return 3;
700     }
701     return 2;
702 }
703 
704 static int rsa_sig_info_set(X509_SIG_INFO *siginf, const X509_ALGOR *sigalg,
705                             const ASN1_STRING *sig)
706 {
707     int rv = 0;
708     int mdnid, saltlen;
709     uint32_t flags;
710     const EVP_MD *mgf1md = NULL, *md = NULL;
711     RSA_PSS_PARAMS *pss;
712     int secbits;
713 
714     /* Sanity check: make sure it is PSS */
715     if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS)
716         return 0;
717     /* Decode PSS parameters */
718     pss = ossl_rsa_pss_decode(sigalg);
719     if (!ossl_rsa_pss_get_param(pss, &md, &mgf1md, &saltlen))
720         goto err;
721     mdnid = EVP_MD_get_type(md);
722     /*
723      * For TLS need SHA256, SHA384 or SHA512, digest and MGF1 digest must
724      * match and salt length must equal digest size
725      */
726     if ((mdnid == NID_sha256 || mdnid == NID_sha384 || mdnid == NID_sha512)
727             && mdnid == EVP_MD_get_type(mgf1md)
728             && saltlen == EVP_MD_get_size(md))
729         flags = X509_SIG_INFO_TLS;
730     else
731         flags = 0;
732     /* Note: security bits half number of digest bits */
733     secbits = EVP_MD_get_size(md) * 4;
734     /*
735      * SHA1 and MD5 are known to be broken. Reduce security bits so that
736      * they're no longer accepted at security level 1. The real values don't
737      * really matter as long as they're lower than 80, which is our security
738      * level 1.
739      * https://eprint.iacr.org/2020/014 puts a chosen-prefix attack for SHA1 at
740      * 2^63.4
741      * https://documents.epfl.ch/users/l/le/lenstra/public/papers/lat.pdf
742      * puts a chosen-prefix attack for MD5 at 2^39.
743      */
744     if (mdnid == NID_sha1)
745         secbits = 64;
746     else if (mdnid == NID_md5_sha1)
747         secbits = 68;
748     else if (mdnid == NID_md5)
749         secbits = 39;
750     X509_SIG_INFO_set(siginf, mdnid, EVP_PKEY_RSA_PSS, secbits,
751                       flags);
752     rv = 1;
753     err:
754     RSA_PSS_PARAMS_free(pss);
755     return rv;
756 }
757 
758 static int rsa_pkey_check(const EVP_PKEY *pkey)
759 {
760     return RSA_check_key_ex(pkey->pkey.rsa, NULL);
761 }
762 
763 static size_t rsa_pkey_dirty_cnt(const EVP_PKEY *pkey)
764 {
765     return pkey->pkey.rsa->dirty_cnt;
766 }
767 
768 /*
769  * There is no need to do RSA_test_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS)
770  * checks in this method since the caller tests EVP_KEYMGMT_is_a() first.
771  */
772 static int rsa_int_export_to(const EVP_PKEY *from, int rsa_type,
773                              void *to_keydata,
774                              OSSL_FUNC_keymgmt_import_fn *importer,
775                              OSSL_LIB_CTX *libctx, const char *propq)
776 {
777     RSA *rsa = from->pkey.rsa;
778     OSSL_PARAM_BLD *tmpl = OSSL_PARAM_BLD_new();
779     OSSL_PARAM *params = NULL;
780     int selection = 0;
781     int rv = 0;
782 
783     if (tmpl == NULL)
784         return 0;
785     /* Public parameters must always be present */
786     if (RSA_get0_n(rsa) == NULL || RSA_get0_e(rsa) == NULL)
787         goto err;
788 
789     if (!ossl_rsa_todata(rsa, tmpl, NULL, 1))
790         goto err;
791 
792     selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
793     if (RSA_get0_d(rsa) != NULL)
794         selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
795 
796     if (rsa->pss != NULL) {
797         const EVP_MD *md = NULL, *mgf1md = NULL;
798         int md_nid, mgf1md_nid, saltlen, trailerfield;
799         RSA_PSS_PARAMS_30 pss_params;
800 
801         if (!ossl_rsa_pss_get_param_unverified(rsa->pss, &md, &mgf1md,
802                                                &saltlen, &trailerfield))
803             goto err;
804         md_nid = EVP_MD_get_type(md);
805         mgf1md_nid = EVP_MD_get_type(mgf1md);
806         if (!ossl_rsa_pss_params_30_set_defaults(&pss_params)
807             || !ossl_rsa_pss_params_30_set_hashalg(&pss_params, md_nid)
808             || !ossl_rsa_pss_params_30_set_maskgenhashalg(&pss_params,
809                                                           mgf1md_nid)
810             || !ossl_rsa_pss_params_30_set_saltlen(&pss_params, saltlen)
811             || !ossl_rsa_pss_params_30_todata(&pss_params, tmpl, NULL))
812             goto err;
813         selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
814     }
815 
816     if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
817         goto err;
818 
819     /* We export, the provider imports */
820     rv = importer(to_keydata, selection, params);
821 
822  err:
823     OSSL_PARAM_free(params);
824     OSSL_PARAM_BLD_free(tmpl);
825     return rv;
826 }
827 
828 static int rsa_int_import_from(const OSSL_PARAM params[], void *vpctx,
829                                int rsa_type)
830 {
831     EVP_PKEY_CTX *pctx = vpctx;
832     EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
833     RSA *rsa = ossl_rsa_new_with_ctx(pctx->libctx);
834     RSA_PSS_PARAMS_30 rsa_pss_params = { 0, };
835     int pss_defaults_set = 0;
836     int ok = 0;
837 
838     if (rsa == NULL) {
839         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
840         return 0;
841     }
842 
843     RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
844     RSA_set_flags(rsa, rsa_type);
845 
846     if (!ossl_rsa_pss_params_30_fromdata(&rsa_pss_params, &pss_defaults_set,
847                                          params, pctx->libctx))
848         goto err;
849 
850     switch (rsa_type) {
851     case RSA_FLAG_TYPE_RSA:
852         /*
853          * Were PSS parameters filled in?
854          * In that case, something's wrong
855          */
856         if (!ossl_rsa_pss_params_30_is_unrestricted(&rsa_pss_params))
857             goto err;
858         break;
859     case RSA_FLAG_TYPE_RSASSAPSS:
860         /*
861          * Were PSS parameters filled in?  In that case, create the old
862          * RSA_PSS_PARAMS structure.  Otherwise, this is an unrestricted key.
863          */
864         if (!ossl_rsa_pss_params_30_is_unrestricted(&rsa_pss_params)) {
865             /* Create the older RSA_PSS_PARAMS from RSA_PSS_PARAMS_30 data */
866             int mdnid = ossl_rsa_pss_params_30_hashalg(&rsa_pss_params);
867             int mgf1mdnid = ossl_rsa_pss_params_30_maskgenhashalg(&rsa_pss_params);
868             int saltlen = ossl_rsa_pss_params_30_saltlen(&rsa_pss_params);
869             const EVP_MD *md = EVP_get_digestbynid(mdnid);
870             const EVP_MD *mgf1md = EVP_get_digestbynid(mgf1mdnid);
871 
872             if ((rsa->pss = ossl_rsa_pss_params_create(md, mgf1md,
873                                                        saltlen)) == NULL)
874                 goto err;
875         }
876         break;
877     default:
878         /* RSA key sub-types we don't know how to handle yet */
879         goto err;
880     }
881 
882     if (!ossl_rsa_fromdata(rsa, params, 1))
883         goto err;
884 
885     switch (rsa_type) {
886     case RSA_FLAG_TYPE_RSA:
887         ok = EVP_PKEY_assign_RSA(pkey, rsa);
888         break;
889     case RSA_FLAG_TYPE_RSASSAPSS:
890         ok = EVP_PKEY_assign(pkey, EVP_PKEY_RSA_PSS, rsa);
891         break;
892     }
893 
894  err:
895     if (!ok)
896         RSA_free(rsa);
897     return ok;
898 }
899 
900 static int rsa_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
901                               OSSL_FUNC_keymgmt_import_fn *importer,
902                               OSSL_LIB_CTX *libctx, const char *propq)
903 {
904     return rsa_int_export_to(from, RSA_FLAG_TYPE_RSA, to_keydata,
905                              importer, libctx, propq);
906 }
907 
908 static int rsa_pss_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
909                                   OSSL_FUNC_keymgmt_import_fn *importer,
910                                   OSSL_LIB_CTX *libctx, const char *propq)
911 {
912     return rsa_int_export_to(from, RSA_FLAG_TYPE_RSASSAPSS, to_keydata,
913                              importer, libctx, propq);
914 }
915 
916 static int rsa_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
917 {
918     return rsa_int_import_from(params, vpctx, RSA_FLAG_TYPE_RSA);
919 }
920 
921 static int rsa_pss_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
922 {
923     return rsa_int_import_from(params, vpctx, RSA_FLAG_TYPE_RSASSAPSS);
924 }
925 
926 static int rsa_pkey_copy(EVP_PKEY *to, EVP_PKEY *from)
927 {
928     RSA *rsa = from->pkey.rsa;
929     RSA *dupkey = NULL;
930     int ret;
931 
932     if (rsa != NULL) {
933         dupkey = ossl_rsa_dup(rsa, OSSL_KEYMGMT_SELECT_ALL);
934         if (dupkey == NULL)
935             return 0;
936     }
937 
938     ret = EVP_PKEY_assign(to, from->type, dupkey);
939     if (!ret)
940         RSA_free(dupkey);
941     return ret;
942 }
943 
944 const EVP_PKEY_ASN1_METHOD ossl_rsa_asn1_meths[2] = {
945     {
946      EVP_PKEY_RSA,
947      EVP_PKEY_RSA,
948      ASN1_PKEY_SIGPARAM_NULL,
949 
950      "RSA",
951      "OpenSSL RSA method",
952 
953      rsa_pub_decode,
954      rsa_pub_encode,
955      rsa_pub_cmp,
956      rsa_pub_print,
957 
958      rsa_priv_decode,
959      rsa_priv_encode,
960      rsa_priv_print,
961 
962      int_rsa_size,
963      rsa_bits,
964      rsa_security_bits,
965 
966      0, 0, 0, 0, 0, 0,
967 
968      rsa_sig_print,
969      int_rsa_free,
970      rsa_pkey_ctrl,
971      old_rsa_priv_decode,
972      old_rsa_priv_encode,
973      rsa_item_verify,
974      rsa_item_sign,
975      rsa_sig_info_set,
976      rsa_pkey_check,
977 
978      0, 0,
979      0, 0, 0, 0,
980 
981      rsa_pkey_dirty_cnt,
982      rsa_pkey_export_to,
983      rsa_pkey_import_from,
984      rsa_pkey_copy
985     },
986 
987     {
988      EVP_PKEY_RSA2,
989      EVP_PKEY_RSA,
990      ASN1_PKEY_ALIAS}
991 };
992 
993 const EVP_PKEY_ASN1_METHOD ossl_rsa_pss_asn1_meth = {
994      EVP_PKEY_RSA_PSS,
995      EVP_PKEY_RSA_PSS,
996      ASN1_PKEY_SIGPARAM_NULL,
997 
998      "RSA-PSS",
999      "OpenSSL RSA-PSS method",
1000 
1001      rsa_pub_decode,
1002      rsa_pub_encode,
1003      rsa_pub_cmp,
1004      rsa_pub_print,
1005 
1006      rsa_priv_decode,
1007      rsa_priv_encode,
1008      rsa_priv_print,
1009 
1010      int_rsa_size,
1011      rsa_bits,
1012      rsa_security_bits,
1013 
1014      0, 0, 0, 0, 0, 0,
1015 
1016      rsa_sig_print,
1017      int_rsa_free,
1018      rsa_pkey_ctrl,
1019      0, 0,
1020      rsa_item_verify,
1021      rsa_item_sign,
1022      rsa_sig_info_set,
1023      rsa_pkey_check,
1024 
1025      0, 0,
1026      0, 0, 0, 0,
1027 
1028      rsa_pkey_dirty_cnt,
1029      rsa_pss_pkey_export_to,
1030      rsa_pss_pkey_import_from,
1031      rsa_pkey_copy
1032 };
1033