1/*
2 * Copyright 2020-2022 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 <string.h>
17#include <openssl/core_names.h>
18#include <openssl/params.h>
19#include <openssl/err.h>
20#include <openssl/evp.h>
21#ifndef FIPS_MODULE
22# include <openssl/x509.h>
23# include "crypto/asn1.h"
24#endif
25#include "internal/sizes.h"
26#include "internal/param_build_set.h"
27#include "crypto/rsa.h"
28#include "rsa_local.h"
29
30/*
31 * The intention with the "backend" source file is to offer backend support
32 * for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
33 * implementations alike.
34 */
35
36DEFINE_STACK_OF(BIGNUM)
37
38static int collect_numbers(STACK_OF(BIGNUM) *numbers,
39                           const OSSL_PARAM params[], const char *names[])
40{
41    const OSSL_PARAM *p = NULL;
42    int i;
43
44    if (numbers == NULL)
45        return 0;
46
47    for (i = 0; names[i] != NULL; i++){
48        p = OSSL_PARAM_locate_const(params, names[i]);
49        if (p != NULL) {
50            BIGNUM *tmp = NULL;
51
52            if (!OSSL_PARAM_get_BN(p, &tmp))
53                return 0;
54            if (sk_BIGNUM_push(numbers, tmp) == 0) {
55                BN_clear_free(tmp);
56                return 0;
57            }
58        }
59    }
60
61    return 1;
62}
63
64int ossl_rsa_fromdata(RSA *rsa, const OSSL_PARAM params[], int include_private)
65{
66    const OSSL_PARAM *param_n, *param_e,  *param_d = NULL;
67    BIGNUM *n = NULL, *e = NULL, *d = NULL;
68    STACK_OF(BIGNUM) *factors = NULL, *exps = NULL, *coeffs = NULL;
69    int is_private = 0;
70
71    if (rsa == NULL)
72        return 0;
73
74    param_n = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_N);
75    param_e = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_E);
76    if (include_private)
77        param_d = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_D);
78
79    if ((param_n != NULL && !OSSL_PARAM_get_BN(param_n, &n))
80        || (param_e != NULL && !OSSL_PARAM_get_BN(param_e, &e))
81        || (param_d != NULL && !OSSL_PARAM_get_BN(param_d, &d)))
82        goto err;
83
84    is_private = (d != NULL);
85
86    if (!RSA_set0_key(rsa, n, e, d))
87        goto err;
88    n = e = d = NULL;
89
90    if (is_private) {
91        if (!collect_numbers(factors = sk_BIGNUM_new_null(), params,
92                             ossl_rsa_mp_factor_names)
93            || !collect_numbers(exps = sk_BIGNUM_new_null(), params,
94                                ossl_rsa_mp_exp_names)
95            || !collect_numbers(coeffs = sk_BIGNUM_new_null(), params,
96                                ossl_rsa_mp_coeff_names))
97            goto err;
98
99        /* It's ok if this private key just has n, e and d */
100        if (sk_BIGNUM_num(factors) != 0
101            && !ossl_rsa_set0_all_params(rsa, factors, exps, coeffs))
102            goto err;
103    }
104
105
106    sk_BIGNUM_free(factors);
107    sk_BIGNUM_free(exps);
108    sk_BIGNUM_free(coeffs);
109    return 1;
110
111 err:
112    BN_free(n);
113    BN_free(e);
114    BN_free(d);
115    sk_BIGNUM_pop_free(factors, BN_free);
116    sk_BIGNUM_pop_free(exps, BN_free);
117    sk_BIGNUM_pop_free(coeffs, BN_free);
118    return 0;
119}
120
121DEFINE_SPECIAL_STACK_OF_CONST(BIGNUM_const, BIGNUM)
122
123int ossl_rsa_todata(RSA *rsa, OSSL_PARAM_BLD *bld, OSSL_PARAM params[],
124                    int include_private)
125{
126    int ret = 0;
127    const BIGNUM *rsa_d = NULL, *rsa_n = NULL, *rsa_e = NULL;
128    STACK_OF(BIGNUM_const) *factors = sk_BIGNUM_const_new_null();
129    STACK_OF(BIGNUM_const) *exps = sk_BIGNUM_const_new_null();
130    STACK_OF(BIGNUM_const) *coeffs = sk_BIGNUM_const_new_null();
131
132    if (rsa == NULL || factors == NULL || exps == NULL || coeffs == NULL)
133        goto err;
134
135    RSA_get0_key(rsa, &rsa_n, &rsa_e, &rsa_d);
136    ossl_rsa_get0_all_params(rsa, factors, exps, coeffs);
137
138    if (!ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_N, rsa_n)
139        || !ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_E, rsa_e))
140        goto err;
141
142    /* Check private key data integrity */
143    if (include_private && rsa_d != NULL) {
144        int numprimes = sk_BIGNUM_const_num(factors);
145        int numexps = sk_BIGNUM_const_num(exps);
146        int numcoeffs = sk_BIGNUM_const_num(coeffs);
147
148        /*
149         * It's permissible to have zero primes, i.e. no CRT params.
150         * Otherwise, there must be at least two, as many exponents,
151         * and one coefficient less.
152         */
153        if (numprimes != 0
154            && (numprimes < 2 || numexps < 2 || numcoeffs < 1))
155            goto err;
156
157        if (!ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_D,
158                                     rsa_d)
159            || !ossl_param_build_set_multi_key_bn(bld, params,
160                                                  ossl_rsa_mp_factor_names,
161                                                  factors)
162            || !ossl_param_build_set_multi_key_bn(bld, params,
163                                                  ossl_rsa_mp_exp_names, exps)
164            || !ossl_param_build_set_multi_key_bn(bld, params,
165                                                  ossl_rsa_mp_coeff_names,
166                                                  coeffs))
167        goto err;
168    }
169
170#if defined(FIPS_MODULE) && !defined(OPENSSL_NO_ACVP_TESTS)
171    /* The acvp test results are not meant for export so check for bld == NULL */
172    if (bld == NULL)
173        ossl_rsa_acvp_test_get_params(rsa, params);
174#endif
175    ret = 1;
176 err:
177    sk_BIGNUM_const_free(factors);
178    sk_BIGNUM_const_free(exps);
179    sk_BIGNUM_const_free(coeffs);
180    return ret;
181}
182
183int ossl_rsa_pss_params_30_todata(const RSA_PSS_PARAMS_30 *pss,
184                                  OSSL_PARAM_BLD *bld, OSSL_PARAM params[])
185{
186    if (!ossl_rsa_pss_params_30_is_unrestricted(pss)) {
187        int hashalg_nid = ossl_rsa_pss_params_30_hashalg(pss);
188        int maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(pss);
189        int maskgenhashalg_nid = ossl_rsa_pss_params_30_maskgenhashalg(pss);
190        int saltlen = ossl_rsa_pss_params_30_saltlen(pss);
191        int default_hashalg_nid = ossl_rsa_pss_params_30_hashalg(NULL);
192        int default_maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(NULL);
193        int default_maskgenhashalg_nid =
194                ossl_rsa_pss_params_30_maskgenhashalg(NULL);
195        const char *mdname =
196            (hashalg_nid == default_hashalg_nid
197             ? NULL : ossl_rsa_oaeppss_nid2name(hashalg_nid));
198        const char *mgfname =
199            (maskgenalg_nid == default_maskgenalg_nid
200             ? NULL : ossl_rsa_oaeppss_nid2name(maskgenalg_nid));
201        const char *mgf1mdname =
202            (maskgenhashalg_nid == default_maskgenhashalg_nid
203             ? NULL : ossl_rsa_oaeppss_nid2name(maskgenhashalg_nid));
204        const char *key_md = OSSL_PKEY_PARAM_RSA_DIGEST;
205        const char *key_mgf = OSSL_PKEY_PARAM_RSA_MASKGENFUNC;
206        const char *key_mgf1_md = OSSL_PKEY_PARAM_RSA_MGF1_DIGEST;
207        const char *key_saltlen = OSSL_PKEY_PARAM_RSA_PSS_SALTLEN;
208
209        /*
210         * To ensure that the key isn't seen as unrestricted by the recipient,
211         * we make sure that at least one PSS-related parameter is passed, even
212         * if it has a default value; saltlen.
213         */
214        if ((mdname != NULL
215             && !ossl_param_build_set_utf8_string(bld, params, key_md, mdname))
216            || (mgfname != NULL
217                && !ossl_param_build_set_utf8_string(bld, params,
218                                                     key_mgf, mgfname))
219            || (mgf1mdname != NULL
220                && !ossl_param_build_set_utf8_string(bld, params,
221                                                     key_mgf1_md, mgf1mdname))
222            || (!ossl_param_build_set_int(bld, params, key_saltlen, saltlen)))
223            return 0;
224    }
225    return 1;
226}
227
228int ossl_rsa_pss_params_30_fromdata(RSA_PSS_PARAMS_30 *pss_params,
229                                    int *defaults_set,
230                                    const OSSL_PARAM params[],
231                                    OSSL_LIB_CTX *libctx)
232{
233    const OSSL_PARAM *param_md, *param_mgf, *param_mgf1md,  *param_saltlen;
234    const OSSL_PARAM *param_propq;
235    const char *propq = NULL;
236    EVP_MD *md = NULL, *mgf1md = NULL;
237    int saltlen;
238    int ret = 0;
239
240    if (pss_params == NULL)
241        return 0;
242    param_propq =
243        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_DIGEST_PROPS);
244    param_md =
245        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_DIGEST);
246    param_mgf =
247        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_MASKGENFUNC);
248    param_mgf1md =
249        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_MGF1_DIGEST);
250    param_saltlen =
251        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_PSS_SALTLEN);
252
253    if (param_propq != NULL) {
254        if (param_propq->data_type == OSSL_PARAM_UTF8_STRING)
255            propq = param_propq->data;
256    }
257    /*
258     * If we get any of the parameters, we know we have at least some
259     * restrictions, so we start by setting default values, and let each
260     * parameter override their specific restriction data.
261     */
262    if (!*defaults_set
263        && (param_md != NULL || param_mgf != NULL || param_mgf1md != NULL
264            || param_saltlen != NULL)) {
265        if (!ossl_rsa_pss_params_30_set_defaults(pss_params))
266            return 0;
267        *defaults_set = 1;
268    }
269
270    if (param_mgf != NULL) {
271        int default_maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(NULL);
272        const char *mgfname = NULL;
273
274        if (param_mgf->data_type == OSSL_PARAM_UTF8_STRING)
275            mgfname = param_mgf->data;
276        else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mgfname))
277            return 0;
278
279        if (OPENSSL_strcasecmp(param_mgf->data,
280                               ossl_rsa_mgf_nid2name(default_maskgenalg_nid)) != 0)
281            return 0;
282    }
283
284    /*
285     * We're only interested in the NIDs that correspond to the MDs, so the
286     * exact propquery is unimportant in the EVP_MD_fetch() calls below.
287     */
288
289    if (param_md != NULL) {
290        const char *mdname = NULL;
291
292        if (param_md->data_type == OSSL_PARAM_UTF8_STRING)
293            mdname = param_md->data;
294        else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mdname))
295            goto err;
296
297        if ((md = EVP_MD_fetch(libctx, mdname, propq)) == NULL
298            || !ossl_rsa_pss_params_30_set_hashalg(pss_params,
299                                                   ossl_rsa_oaeppss_md2nid(md)))
300            goto err;
301    }
302
303    if (param_mgf1md != NULL) {
304        const char *mgf1mdname = NULL;
305
306        if (param_mgf1md->data_type == OSSL_PARAM_UTF8_STRING)
307            mgf1mdname = param_mgf1md->data;
308        else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mgf1mdname))
309            goto err;
310
311        if ((mgf1md = EVP_MD_fetch(libctx, mgf1mdname, propq)) == NULL
312            || !ossl_rsa_pss_params_30_set_maskgenhashalg(
313                    pss_params, ossl_rsa_oaeppss_md2nid(mgf1md)))
314            goto err;
315    }
316
317    if (param_saltlen != NULL) {
318        if (!OSSL_PARAM_get_int(param_saltlen, &saltlen)
319            || !ossl_rsa_pss_params_30_set_saltlen(pss_params, saltlen))
320            goto err;
321    }
322
323    ret = 1;
324
325 err:
326    EVP_MD_free(md);
327    EVP_MD_free(mgf1md);
328    return ret;
329}
330
331int ossl_rsa_is_foreign(const RSA *rsa)
332{
333#ifndef FIPS_MODULE
334    if (rsa->engine != NULL || RSA_get_method(rsa) != RSA_PKCS1_OpenSSL())
335        return 1;
336#endif
337    return 0;
338}
339
340static ossl_inline int rsa_bn_dup_check(BIGNUM **out, const BIGNUM *f)
341{
342    if (f != NULL && (*out = BN_dup(f)) == NULL)
343        return 0;
344    return 1;
345}
346
347RSA *ossl_rsa_dup(const RSA *rsa, int selection)
348{
349    RSA *dupkey = NULL;
350#ifndef FIPS_MODULE
351    int pnum, i;
352#endif
353
354    /* Do not try to duplicate foreign RSA keys */
355    if (ossl_rsa_is_foreign(rsa))
356        return NULL;
357
358    if ((dupkey = ossl_rsa_new_with_ctx(rsa->libctx)) == NULL)
359        return NULL;
360
361    /* public key */
362    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0) {
363        if (!rsa_bn_dup_check(&dupkey->n, rsa->n))
364            goto err;
365        if (!rsa_bn_dup_check(&dupkey->e, rsa->e))
366            goto err;
367    }
368
369    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0) {
370
371        /* private key */
372        if (!rsa_bn_dup_check(&dupkey->d, rsa->d))
373            goto err;
374
375        /* factors and crt params */
376        if (!rsa_bn_dup_check(&dupkey->p, rsa->p))
377            goto err;
378        if (!rsa_bn_dup_check(&dupkey->q, rsa->q))
379            goto err;
380        if (!rsa_bn_dup_check(&dupkey->dmp1, rsa->dmp1))
381            goto err;
382        if (!rsa_bn_dup_check(&dupkey->dmq1, rsa->dmq1))
383            goto err;
384        if (!rsa_bn_dup_check(&dupkey->iqmp, rsa->iqmp))
385            goto err;
386    }
387
388    dupkey->version = rsa->version;
389    dupkey->flags = rsa->flags;
390    /* we always copy the PSS parameters regardless of selection */
391    dupkey->pss_params = rsa->pss_params;
392
393#ifndef FIPS_MODULE
394    /* multiprime */
395    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0
396        && (pnum = sk_RSA_PRIME_INFO_num(rsa->prime_infos)) > 0) {
397        dupkey->prime_infos = sk_RSA_PRIME_INFO_new_reserve(NULL, pnum);
398        if (dupkey->prime_infos == NULL)
399            goto err;
400        for (i = 0; i < pnum; i++) {
401            const RSA_PRIME_INFO *pinfo = NULL;
402            RSA_PRIME_INFO *duppinfo = NULL;
403
404            if ((duppinfo = OPENSSL_zalloc(sizeof(*duppinfo))) == NULL) {
405                ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE);
406                goto err;
407            }
408            /* push first so cleanup in error case works */
409            (void)sk_RSA_PRIME_INFO_push(dupkey->prime_infos, duppinfo);
410
411            pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i);
412            if (!rsa_bn_dup_check(&duppinfo->r, pinfo->r))
413                goto err;
414            if (!rsa_bn_dup_check(&duppinfo->d, pinfo->d))
415                goto err;
416            if (!rsa_bn_dup_check(&duppinfo->t, pinfo->t))
417                goto err;
418        }
419        if (!ossl_rsa_multip_calc_product(dupkey))
420            goto err;
421    }
422
423    if (rsa->pss != NULL) {
424        dupkey->pss = RSA_PSS_PARAMS_dup(rsa->pss);
425        if (rsa->pss->maskGenAlgorithm != NULL
426            && dupkey->pss->maskGenAlgorithm == NULL) {
427            dupkey->pss->maskHash = ossl_x509_algor_mgf1_decode(rsa->pss->maskGenAlgorithm);
428            if (dupkey->pss->maskHash == NULL)
429                goto err;
430        }
431    }
432    if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_RSA,
433                            &dupkey->ex_data, &rsa->ex_data))
434        goto err;
435#endif
436
437    return dupkey;
438
439 err:
440    RSA_free(dupkey);
441    return NULL;
442}
443
444#ifndef FIPS_MODULE
445RSA_PSS_PARAMS *ossl_rsa_pss_decode(const X509_ALGOR *alg)
446{
447    RSA_PSS_PARAMS *pss;
448
449    pss = ASN1_TYPE_unpack_sequence(ASN1_ITEM_rptr(RSA_PSS_PARAMS),
450                                    alg->parameter);
451
452    if (pss == NULL)
453        return NULL;
454
455    if (pss->maskGenAlgorithm != NULL) {
456        pss->maskHash = ossl_x509_algor_mgf1_decode(pss->maskGenAlgorithm);
457        if (pss->maskHash == NULL) {
458            RSA_PSS_PARAMS_free(pss);
459            return NULL;
460        }
461    }
462
463    return pss;
464}
465
466static int ossl_rsa_sync_to_pss_params_30(RSA *rsa)
467{
468    const RSA_PSS_PARAMS *legacy_pss = NULL;
469    RSA_PSS_PARAMS_30 *pss = NULL;
470
471    if (rsa != NULL
472        && (legacy_pss = RSA_get0_pss_params(rsa)) != NULL
473        && (pss = ossl_rsa_get0_pss_params_30(rsa)) != NULL) {
474        const EVP_MD *md = NULL, *mgf1md = NULL;
475        int md_nid, mgf1md_nid, saltlen, trailerField;
476        RSA_PSS_PARAMS_30 pss_params;
477
478        /*
479         * We don't care about the validity of the fields here, we just
480         * want to synchronise values.  Verifying here makes it impossible
481         * to even read a key with invalid values, making it hard to test
482         * a bad situation.
483         *
484         * Other routines use ossl_rsa_pss_get_param(), so the values will
485         * be checked, eventually.
486         */
487        if (!ossl_rsa_pss_get_param_unverified(legacy_pss, &md, &mgf1md,
488                                               &saltlen, &trailerField))
489            return 0;
490        md_nid = EVP_MD_get_type(md);
491        mgf1md_nid = EVP_MD_get_type(mgf1md);
492        if (!ossl_rsa_pss_params_30_set_defaults(&pss_params)
493            || !ossl_rsa_pss_params_30_set_hashalg(&pss_params, md_nid)
494            || !ossl_rsa_pss_params_30_set_maskgenhashalg(&pss_params,
495                                                          mgf1md_nid)
496            || !ossl_rsa_pss_params_30_set_saltlen(&pss_params, saltlen)
497            || !ossl_rsa_pss_params_30_set_trailerfield(&pss_params,
498                                                        trailerField))
499            return 0;
500        *pss = pss_params;
501    }
502    return 1;
503}
504
505int ossl_rsa_pss_get_param_unverified(const RSA_PSS_PARAMS *pss,
506                                      const EVP_MD **pmd, const EVP_MD **pmgf1md,
507                                      int *psaltlen, int *ptrailerField)
508{
509    RSA_PSS_PARAMS_30 pss_params;
510
511    /* Get the defaults from the ONE place */
512    (void)ossl_rsa_pss_params_30_set_defaults(&pss_params);
513
514    if (pss == NULL)
515        return 0;
516    *pmd = ossl_x509_algor_get_md(pss->hashAlgorithm);
517    if (*pmd == NULL)
518        return 0;
519    *pmgf1md = ossl_x509_algor_get_md(pss->maskHash);
520    if (*pmgf1md == NULL)
521        return 0;
522    if (pss->saltLength)
523        *psaltlen = ASN1_INTEGER_get(pss->saltLength);
524    else
525        *psaltlen = ossl_rsa_pss_params_30_saltlen(&pss_params);
526    if (pss->trailerField)
527        *ptrailerField = ASN1_INTEGER_get(pss->trailerField);
528    else
529        *ptrailerField = ossl_rsa_pss_params_30_trailerfield(&pss_params);;
530
531    return 1;
532}
533
534int ossl_rsa_param_decode(RSA *rsa, const X509_ALGOR *alg)
535{
536    RSA_PSS_PARAMS *pss;
537    const ASN1_OBJECT *algoid;
538    const void *algp;
539    int algptype;
540
541    X509_ALGOR_get0(&algoid, &algptype, &algp, alg);
542    if (OBJ_obj2nid(algoid) != EVP_PKEY_RSA_PSS)
543        return 1;
544    if (algptype == V_ASN1_UNDEF)
545        return 1;
546    if (algptype != V_ASN1_SEQUENCE) {
547        ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_PSS_PARAMETERS);
548        return 0;
549    }
550    if ((pss = ossl_rsa_pss_decode(alg)) == NULL
551        || !ossl_rsa_set0_pss_params(rsa, pss)) {
552        RSA_PSS_PARAMS_free(pss);
553        return 0;
554    }
555    if (!ossl_rsa_sync_to_pss_params_30(rsa))
556        return 0;
557    return 1;
558}
559
560RSA *ossl_rsa_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO *p8inf,
561                             OSSL_LIB_CTX *libctx, const char *propq)
562{
563    const unsigned char *p;
564    RSA *rsa;
565    int pklen;
566    const X509_ALGOR *alg;
567
568    if (!PKCS8_pkey_get0(NULL, &p, &pklen, &alg, p8inf))
569        return 0;
570    rsa = d2i_RSAPrivateKey(NULL, &p, pklen);
571    if (rsa == NULL) {
572        ERR_raise(ERR_LIB_RSA, ERR_R_RSA_LIB);
573        return NULL;
574    }
575    if (!ossl_rsa_param_decode(rsa, alg)) {
576        RSA_free(rsa);
577        return NULL;
578    }
579
580    RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
581    switch (OBJ_obj2nid(alg->algorithm)) {
582    case EVP_PKEY_RSA:
583        RSA_set_flags(rsa, RSA_FLAG_TYPE_RSA);
584        break;
585    case EVP_PKEY_RSA_PSS:
586        RSA_set_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS);
587        break;
588    default:
589        /* Leave the type bits zero */
590        break;
591    }
592
593    return rsa;
594}
595#endif
596