1/*
2 * Copyright 2020-2023 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 <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
145        if (!ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_D,
146                                     rsa_d)
147            || !ossl_param_build_set_multi_key_bn(bld, params,
148                                                  ossl_rsa_mp_factor_names,
149                                                  factors)
150            || !ossl_param_build_set_multi_key_bn(bld, params,
151                                                  ossl_rsa_mp_exp_names, exps)
152            || !ossl_param_build_set_multi_key_bn(bld, params,
153                                                  ossl_rsa_mp_coeff_names,
154                                                  coeffs))
155        goto err;
156    }
157
158#if defined(FIPS_MODULE) && !defined(OPENSSL_NO_ACVP_TESTS)
159    /* The acvp test results are not meant for export so check for bld == NULL */
160    if (bld == NULL)
161        ossl_rsa_acvp_test_get_params(rsa, params);
162#endif
163    ret = 1;
164 err:
165    sk_BIGNUM_const_free(factors);
166    sk_BIGNUM_const_free(exps);
167    sk_BIGNUM_const_free(coeffs);
168    return ret;
169}
170
171int ossl_rsa_pss_params_30_todata(const RSA_PSS_PARAMS_30 *pss,
172                                  OSSL_PARAM_BLD *bld, OSSL_PARAM params[])
173{
174    if (!ossl_rsa_pss_params_30_is_unrestricted(pss)) {
175        int hashalg_nid = ossl_rsa_pss_params_30_hashalg(pss);
176        int maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(pss);
177        int maskgenhashalg_nid = ossl_rsa_pss_params_30_maskgenhashalg(pss);
178        int saltlen = ossl_rsa_pss_params_30_saltlen(pss);
179        int default_hashalg_nid = ossl_rsa_pss_params_30_hashalg(NULL);
180        int default_maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(NULL);
181        int default_maskgenhashalg_nid =
182                ossl_rsa_pss_params_30_maskgenhashalg(NULL);
183        const char *mdname =
184            (hashalg_nid == default_hashalg_nid
185             ? NULL : ossl_rsa_oaeppss_nid2name(hashalg_nid));
186        const char *mgfname =
187            (maskgenalg_nid == default_maskgenalg_nid
188             ? NULL : ossl_rsa_oaeppss_nid2name(maskgenalg_nid));
189        const char *mgf1mdname =
190            (maskgenhashalg_nid == default_maskgenhashalg_nid
191             ? NULL : ossl_rsa_oaeppss_nid2name(maskgenhashalg_nid));
192        const char *key_md = OSSL_PKEY_PARAM_RSA_DIGEST;
193        const char *key_mgf = OSSL_PKEY_PARAM_RSA_MASKGENFUNC;
194        const char *key_mgf1_md = OSSL_PKEY_PARAM_RSA_MGF1_DIGEST;
195        const char *key_saltlen = OSSL_PKEY_PARAM_RSA_PSS_SALTLEN;
196
197        /*
198         * To ensure that the key isn't seen as unrestricted by the recipient,
199         * we make sure that at least one PSS-related parameter is passed, even
200         * if it has a default value; saltlen.
201         */
202        if ((mdname != NULL
203             && !ossl_param_build_set_utf8_string(bld, params, key_md, mdname))
204            || (mgfname != NULL
205                && !ossl_param_build_set_utf8_string(bld, params,
206                                                     key_mgf, mgfname))
207            || (mgf1mdname != NULL
208                && !ossl_param_build_set_utf8_string(bld, params,
209                                                     key_mgf1_md, mgf1mdname))
210            || (!ossl_param_build_set_int(bld, params, key_saltlen, saltlen)))
211            return 0;
212    }
213    return 1;
214}
215
216int ossl_rsa_pss_params_30_fromdata(RSA_PSS_PARAMS_30 *pss_params,
217                                    int *defaults_set,
218                                    const OSSL_PARAM params[],
219                                    OSSL_LIB_CTX *libctx)
220{
221    const OSSL_PARAM *param_md, *param_mgf, *param_mgf1md,  *param_saltlen;
222    const OSSL_PARAM *param_propq;
223    const char *propq = NULL;
224    EVP_MD *md = NULL, *mgf1md = NULL;
225    int saltlen;
226    int ret = 0;
227
228    if (pss_params == NULL)
229        return 0;
230    param_propq =
231        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_DIGEST_PROPS);
232    param_md =
233        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_DIGEST);
234    param_mgf =
235        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_MASKGENFUNC);
236    param_mgf1md =
237        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_MGF1_DIGEST);
238    param_saltlen =
239        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_PSS_SALTLEN);
240
241    if (param_propq != NULL) {
242        if (param_propq->data_type == OSSL_PARAM_UTF8_STRING)
243            propq = param_propq->data;
244    }
245    /*
246     * If we get any of the parameters, we know we have at least some
247     * restrictions, so we start by setting default values, and let each
248     * parameter override their specific restriction data.
249     */
250    if (!*defaults_set
251        && (param_md != NULL || param_mgf != NULL || param_mgf1md != NULL
252            || param_saltlen != NULL)) {
253        if (!ossl_rsa_pss_params_30_set_defaults(pss_params))
254            return 0;
255        *defaults_set = 1;
256    }
257
258    if (param_mgf != NULL) {
259        int default_maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(NULL);
260        const char *mgfname = NULL;
261
262        if (param_mgf->data_type == OSSL_PARAM_UTF8_STRING)
263            mgfname = param_mgf->data;
264        else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mgfname))
265            return 0;
266
267        if (OPENSSL_strcasecmp(param_mgf->data,
268                               ossl_rsa_mgf_nid2name(default_maskgenalg_nid)) != 0)
269            return 0;
270    }
271
272    /*
273     * We're only interested in the NIDs that correspond to the MDs, so the
274     * exact propquery is unimportant in the EVP_MD_fetch() calls below.
275     */
276
277    if (param_md != NULL) {
278        const char *mdname = NULL;
279
280        if (param_md->data_type == OSSL_PARAM_UTF8_STRING)
281            mdname = param_md->data;
282        else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mdname))
283            goto err;
284
285        if ((md = EVP_MD_fetch(libctx, mdname, propq)) == NULL
286            || !ossl_rsa_pss_params_30_set_hashalg(pss_params,
287                                                   ossl_rsa_oaeppss_md2nid(md)))
288            goto err;
289    }
290
291    if (param_mgf1md != NULL) {
292        const char *mgf1mdname = NULL;
293
294        if (param_mgf1md->data_type == OSSL_PARAM_UTF8_STRING)
295            mgf1mdname = param_mgf1md->data;
296        else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mgf1mdname))
297            goto err;
298
299        if ((mgf1md = EVP_MD_fetch(libctx, mgf1mdname, propq)) == NULL
300            || !ossl_rsa_pss_params_30_set_maskgenhashalg(
301                    pss_params, ossl_rsa_oaeppss_md2nid(mgf1md)))
302            goto err;
303    }
304
305    if (param_saltlen != NULL) {
306        if (!OSSL_PARAM_get_int(param_saltlen, &saltlen)
307            || !ossl_rsa_pss_params_30_set_saltlen(pss_params, saltlen))
308            goto err;
309    }
310
311    ret = 1;
312
313 err:
314    EVP_MD_free(md);
315    EVP_MD_free(mgf1md);
316    return ret;
317}
318
319int ossl_rsa_is_foreign(const RSA *rsa)
320{
321#ifndef FIPS_MODULE
322    if (rsa->engine != NULL || RSA_get_method(rsa) != RSA_PKCS1_OpenSSL())
323        return 1;
324#endif
325    return 0;
326}
327
328static ossl_inline int rsa_bn_dup_check(BIGNUM **out, const BIGNUM *f)
329{
330    if (f != NULL && (*out = BN_dup(f)) == NULL)
331        return 0;
332    return 1;
333}
334
335RSA *ossl_rsa_dup(const RSA *rsa, int selection)
336{
337    RSA *dupkey = NULL;
338#ifndef FIPS_MODULE
339    int pnum, i;
340#endif
341
342    /* Do not try to duplicate foreign RSA keys */
343    if (ossl_rsa_is_foreign(rsa))
344        return NULL;
345
346    if ((dupkey = ossl_rsa_new_with_ctx(rsa->libctx)) == NULL)
347        return NULL;
348
349    /* public key */
350    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0) {
351        if (!rsa_bn_dup_check(&dupkey->n, rsa->n))
352            goto err;
353        if (!rsa_bn_dup_check(&dupkey->e, rsa->e))
354            goto err;
355    }
356
357    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0) {
358
359        /* private key */
360        if (!rsa_bn_dup_check(&dupkey->d, rsa->d))
361            goto err;
362
363        /* factors and crt params */
364        if (!rsa_bn_dup_check(&dupkey->p, rsa->p))
365            goto err;
366        if (!rsa_bn_dup_check(&dupkey->q, rsa->q))
367            goto err;
368        if (!rsa_bn_dup_check(&dupkey->dmp1, rsa->dmp1))
369            goto err;
370        if (!rsa_bn_dup_check(&dupkey->dmq1, rsa->dmq1))
371            goto err;
372        if (!rsa_bn_dup_check(&dupkey->iqmp, rsa->iqmp))
373            goto err;
374    }
375
376    dupkey->version = rsa->version;
377    dupkey->flags = rsa->flags;
378    /* we always copy the PSS parameters regardless of selection */
379    dupkey->pss_params = rsa->pss_params;
380
381#ifndef FIPS_MODULE
382    /* multiprime */
383    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0
384        && (pnum = sk_RSA_PRIME_INFO_num(rsa->prime_infos)) > 0) {
385        dupkey->prime_infos = sk_RSA_PRIME_INFO_new_reserve(NULL, pnum);
386        if (dupkey->prime_infos == NULL)
387            goto err;
388        for (i = 0; i < pnum; i++) {
389            const RSA_PRIME_INFO *pinfo = NULL;
390            RSA_PRIME_INFO *duppinfo = NULL;
391
392            if ((duppinfo = OPENSSL_zalloc(sizeof(*duppinfo))) == NULL) {
393                ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE);
394                goto err;
395            }
396            /* push first so cleanup in error case works */
397            (void)sk_RSA_PRIME_INFO_push(dupkey->prime_infos, duppinfo);
398
399            pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i);
400            if (!rsa_bn_dup_check(&duppinfo->r, pinfo->r))
401                goto err;
402            if (!rsa_bn_dup_check(&duppinfo->d, pinfo->d))
403                goto err;
404            if (!rsa_bn_dup_check(&duppinfo->t, pinfo->t))
405                goto err;
406        }
407        if (!ossl_rsa_multip_calc_product(dupkey))
408            goto err;
409    }
410
411    if (rsa->pss != NULL) {
412        dupkey->pss = RSA_PSS_PARAMS_dup(rsa->pss);
413        if (rsa->pss->maskGenAlgorithm != NULL
414            && dupkey->pss->maskGenAlgorithm == NULL) {
415            dupkey->pss->maskHash = ossl_x509_algor_mgf1_decode(rsa->pss->maskGenAlgorithm);
416            if (dupkey->pss->maskHash == NULL)
417                goto err;
418        }
419    }
420    if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_RSA,
421                            &dupkey->ex_data, &rsa->ex_data))
422        goto err;
423#endif
424
425    return dupkey;
426
427 err:
428    RSA_free(dupkey);
429    return NULL;
430}
431
432#ifndef FIPS_MODULE
433RSA_PSS_PARAMS *ossl_rsa_pss_decode(const X509_ALGOR *alg)
434{
435    RSA_PSS_PARAMS *pss;
436
437    pss = ASN1_TYPE_unpack_sequence(ASN1_ITEM_rptr(RSA_PSS_PARAMS),
438                                    alg->parameter);
439
440    if (pss == NULL)
441        return NULL;
442
443    if (pss->maskGenAlgorithm != NULL) {
444        pss->maskHash = ossl_x509_algor_mgf1_decode(pss->maskGenAlgorithm);
445        if (pss->maskHash == NULL) {
446            RSA_PSS_PARAMS_free(pss);
447            return NULL;
448        }
449    }
450
451    return pss;
452}
453
454static int ossl_rsa_sync_to_pss_params_30(RSA *rsa)
455{
456    const RSA_PSS_PARAMS *legacy_pss = NULL;
457    RSA_PSS_PARAMS_30 *pss = NULL;
458
459    if (rsa != NULL
460        && (legacy_pss = RSA_get0_pss_params(rsa)) != NULL
461        && (pss = ossl_rsa_get0_pss_params_30(rsa)) != NULL) {
462        const EVP_MD *md = NULL, *mgf1md = NULL;
463        int md_nid, mgf1md_nid, saltlen, trailerField;
464        RSA_PSS_PARAMS_30 pss_params;
465
466        /*
467         * We don't care about the validity of the fields here, we just
468         * want to synchronise values.  Verifying here makes it impossible
469         * to even read a key with invalid values, making it hard to test
470         * a bad situation.
471         *
472         * Other routines use ossl_rsa_pss_get_param(), so the values will
473         * be checked, eventually.
474         */
475        if (!ossl_rsa_pss_get_param_unverified(legacy_pss, &md, &mgf1md,
476                                               &saltlen, &trailerField))
477            return 0;
478        md_nid = EVP_MD_get_type(md);
479        mgf1md_nid = EVP_MD_get_type(mgf1md);
480        if (!ossl_rsa_pss_params_30_set_defaults(&pss_params)
481            || !ossl_rsa_pss_params_30_set_hashalg(&pss_params, md_nid)
482            || !ossl_rsa_pss_params_30_set_maskgenhashalg(&pss_params,
483                                                          mgf1md_nid)
484            || !ossl_rsa_pss_params_30_set_saltlen(&pss_params, saltlen)
485            || !ossl_rsa_pss_params_30_set_trailerfield(&pss_params,
486                                                        trailerField))
487            return 0;
488        *pss = pss_params;
489    }
490    return 1;
491}
492
493int ossl_rsa_pss_get_param_unverified(const RSA_PSS_PARAMS *pss,
494                                      const EVP_MD **pmd, const EVP_MD **pmgf1md,
495                                      int *psaltlen, int *ptrailerField)
496{
497    RSA_PSS_PARAMS_30 pss_params;
498
499    /* Get the defaults from the ONE place */
500    (void)ossl_rsa_pss_params_30_set_defaults(&pss_params);
501
502    if (pss == NULL)
503        return 0;
504    *pmd = ossl_x509_algor_get_md(pss->hashAlgorithm);
505    if (*pmd == NULL)
506        return 0;
507    *pmgf1md = ossl_x509_algor_get_md(pss->maskHash);
508    if (*pmgf1md == NULL)
509        return 0;
510    if (pss->saltLength)
511        *psaltlen = ASN1_INTEGER_get(pss->saltLength);
512    else
513        *psaltlen = ossl_rsa_pss_params_30_saltlen(&pss_params);
514    if (pss->trailerField)
515        *ptrailerField = ASN1_INTEGER_get(pss->trailerField);
516    else
517        *ptrailerField = ossl_rsa_pss_params_30_trailerfield(&pss_params);;
518
519    return 1;
520}
521
522int ossl_rsa_param_decode(RSA *rsa, const X509_ALGOR *alg)
523{
524    RSA_PSS_PARAMS *pss;
525    const ASN1_OBJECT *algoid;
526    const void *algp;
527    int algptype;
528
529    X509_ALGOR_get0(&algoid, &algptype, &algp, alg);
530    if (OBJ_obj2nid(algoid) != EVP_PKEY_RSA_PSS)
531        return 1;
532    if (algptype == V_ASN1_UNDEF)
533        return 1;
534    if (algptype != V_ASN1_SEQUENCE) {
535        ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_PSS_PARAMETERS);
536        return 0;
537    }
538    if ((pss = ossl_rsa_pss_decode(alg)) == NULL
539        || !ossl_rsa_set0_pss_params(rsa, pss)) {
540        RSA_PSS_PARAMS_free(pss);
541        return 0;
542    }
543    if (!ossl_rsa_sync_to_pss_params_30(rsa))
544        return 0;
545    return 1;
546}
547
548RSA *ossl_rsa_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO *p8inf,
549                             OSSL_LIB_CTX *libctx, const char *propq)
550{
551    const unsigned char *p;
552    RSA *rsa;
553    int pklen;
554    const X509_ALGOR *alg;
555
556    if (!PKCS8_pkey_get0(NULL, &p, &pklen, &alg, p8inf))
557        return 0;
558    rsa = d2i_RSAPrivateKey(NULL, &p, pklen);
559    if (rsa == NULL) {
560        ERR_raise(ERR_LIB_RSA, ERR_R_RSA_LIB);
561        return NULL;
562    }
563    if (!ossl_rsa_param_decode(rsa, alg)) {
564        RSA_free(rsa);
565        return NULL;
566    }
567
568    RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
569    switch (OBJ_obj2nid(alg->algorithm)) {
570    case EVP_PKEY_RSA:
571        RSA_set_flags(rsa, RSA_FLAG_TYPE_RSA);
572        break;
573    case EVP_PKEY_RSA_PSS:
574        RSA_set_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS);
575        break;
576    default:
577        /* Leave the type bits zero */
578        break;
579    }
580
581    return rsa;
582}
583#endif
584