2 * Copyright 2006-2019 The OpenSSL Project Authors. All Rights Reserved.
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
11 * RSA low level APIs are deprecated for public use, but still ok for
14 #include "internal/deprecated.h"
16 #include "internal/constant_time.h"
19 #include "internal/cryptlib.h"
20 #include <openssl/asn1t.h>
21 #include <openssl/x509.h>
22 #include <openssl/rsa.h>
23 #include <openssl/bn.h>
24 #include <openssl/evp.h>
25 #include <openssl/x509v3.h>
26 #include <openssl/cms.h>
27 #include "crypto/evp.h"
28 #include "crypto/rsa.h"
29 #include "rsa_local.h"
31 /* RSA pkey context structure */
34 /* Key gen parameters */
38 /* Keygen callback info */
40 /* RSA padding mode */
44 /* message digest for MGF1 */
48 /* Minimum salt length or -1 if no PSS parameter restriction */
53 unsigned char *oaep_label;
57 /* True if PSS parameters are restricted */
58 #define rsa_pss_restricted(rctx) (rctx->min_saltlen != -1)
60 static int pkey_rsa_init(EVP_PKEY_CTX *ctx)
62 RSA_PKEY_CTX *rctx = OPENSSL_zalloc(sizeof(*rctx));
67 rctx->primes = RSA_DEFAULT_PRIME_NUM;
68 if (pkey_ctx_is_pss(ctx))
69 rctx->pad_mode = RSA_PKCS1_PSS_PADDING;
71 rctx->pad_mode = RSA_PKCS1_PADDING;
72 /* Maximum for sign, auto for verify */
73 rctx->saltlen = RSA_PSS_SALTLEN_AUTO;
74 rctx->min_saltlen = -1;
76 ctx->keygen_info = rctx->gentmp;
77 ctx->keygen_info_count = 2;
82 static int pkey_rsa_copy(EVP_PKEY_CTX *dst, const EVP_PKEY_CTX *src)
84 RSA_PKEY_CTX *dctx, *sctx;
86 if (!pkey_rsa_init(dst))
90 dctx->nbits = sctx->nbits;
92 dctx->pub_exp = BN_dup(sctx->pub_exp);
96 dctx->pad_mode = sctx->pad_mode;
98 dctx->mgf1md = sctx->mgf1md;
99 dctx->saltlen = sctx->saltlen;
100 if (sctx->oaep_label) {
101 OPENSSL_free(dctx->oaep_label);
102 dctx->oaep_label = OPENSSL_memdup(sctx->oaep_label, sctx->oaep_labellen);
103 if (!dctx->oaep_label)
105 dctx->oaep_labellen = sctx->oaep_labellen;
110 static int setup_tbuf(RSA_PKEY_CTX *ctx, EVP_PKEY_CTX *pk)
112 if (ctx->tbuf != NULL)
114 if ((ctx->tbuf = OPENSSL_malloc(RSA_size(pk->pkey->pkey.rsa))) == NULL) {
115 RSAerr(RSA_F_SETUP_TBUF, ERR_R_MALLOC_FAILURE);
121 static void pkey_rsa_cleanup(EVP_PKEY_CTX *ctx)
123 RSA_PKEY_CTX *rctx = ctx->data;
125 BN_free(rctx->pub_exp);
126 OPENSSL_free(rctx->tbuf);
127 OPENSSL_free(rctx->oaep_label);
132 static int pkey_rsa_sign(EVP_PKEY_CTX *ctx, unsigned char *sig,
133 size_t *siglen, const unsigned char *tbs,
137 RSA_PKEY_CTX *rctx = ctx->data;
138 RSA *rsa = ctx->pkey->pkey.rsa;
141 if (tbslen != (size_t)EVP_MD_size(rctx->md)) {
142 RSAerr(RSA_F_PKEY_RSA_SIGN, RSA_R_INVALID_DIGEST_LENGTH);
146 if (EVP_MD_type(rctx->md) == NID_mdc2) {
148 if (rctx->pad_mode != RSA_PKCS1_PADDING)
150 ret = RSA_sign_ASN1_OCTET_STRING(0,
151 tbs, tbslen, sig, &sltmp, rsa);
156 } else if (rctx->pad_mode == RSA_X931_PADDING) {
157 if ((size_t)RSA_size(rsa) < tbslen + 1) {
158 RSAerr(RSA_F_PKEY_RSA_SIGN, RSA_R_KEY_SIZE_TOO_SMALL);
161 if (!setup_tbuf(rctx, ctx)) {
162 RSAerr(RSA_F_PKEY_RSA_SIGN, ERR_R_MALLOC_FAILURE);
165 memcpy(rctx->tbuf, tbs, tbslen);
166 rctx->tbuf[tbslen] = RSA_X931_hash_id(EVP_MD_type(rctx->md));
167 ret = RSA_private_encrypt(tbslen + 1, rctx->tbuf,
168 sig, rsa, RSA_X931_PADDING);
169 } else if (rctx->pad_mode == RSA_PKCS1_PADDING) {
171 ret = RSA_sign(EVP_MD_type(rctx->md),
172 tbs, tbslen, sig, &sltmp, rsa);
176 } else if (rctx->pad_mode == RSA_PKCS1_PSS_PADDING) {
177 if (!setup_tbuf(rctx, ctx))
179 if (!RSA_padding_add_PKCS1_PSS_mgf1(rsa,
181 rctx->md, rctx->mgf1md,
184 ret = RSA_private_encrypt(RSA_size(rsa), rctx->tbuf,
185 sig, rsa, RSA_NO_PADDING);
190 ret = RSA_private_encrypt(tbslen, tbs, sig, ctx->pkey->pkey.rsa,
199 static int pkey_rsa_verifyrecover(EVP_PKEY_CTX *ctx,
200 unsigned char *rout, size_t *routlen,
201 const unsigned char *sig, size_t siglen)
204 RSA_PKEY_CTX *rctx = ctx->data;
207 if (rctx->pad_mode == RSA_X931_PADDING) {
208 if (!setup_tbuf(rctx, ctx))
210 ret = RSA_public_decrypt(siglen, sig,
211 rctx->tbuf, ctx->pkey->pkey.rsa,
216 if (rctx->tbuf[ret] != RSA_X931_hash_id(EVP_MD_type(rctx->md))) {
217 RSAerr(RSA_F_PKEY_RSA_VERIFYRECOVER,
218 RSA_R_ALGORITHM_MISMATCH);
221 if (ret != EVP_MD_size(rctx->md)) {
222 RSAerr(RSA_F_PKEY_RSA_VERIFYRECOVER,
223 RSA_R_INVALID_DIGEST_LENGTH);
227 memcpy(rout, rctx->tbuf, ret);
228 } else if (rctx->pad_mode == RSA_PKCS1_PADDING) {
230 ret = int_rsa_verify(EVP_MD_type(rctx->md),
231 NULL, 0, rout, &sltmp,
232 sig, siglen, ctx->pkey->pkey.rsa);
240 ret = RSA_public_decrypt(siglen, sig, rout, ctx->pkey->pkey.rsa,
249 static int pkey_rsa_verify(EVP_PKEY_CTX *ctx,
250 const unsigned char *sig, size_t siglen,
251 const unsigned char *tbs, size_t tbslen)
253 RSA_PKEY_CTX *rctx = ctx->data;
254 RSA *rsa = ctx->pkey->pkey.rsa;
258 if (rctx->pad_mode == RSA_PKCS1_PADDING)
259 return RSA_verify(EVP_MD_type(rctx->md), tbs, tbslen,
261 if (tbslen != (size_t)EVP_MD_size(rctx->md)) {
262 RSAerr(RSA_F_PKEY_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH);
265 if (rctx->pad_mode == RSA_X931_PADDING) {
266 if (pkey_rsa_verifyrecover(ctx, NULL, &rslen, sig, siglen) <= 0)
268 } else if (rctx->pad_mode == RSA_PKCS1_PSS_PADDING) {
270 if (!setup_tbuf(rctx, ctx))
272 ret = RSA_public_decrypt(siglen, sig, rctx->tbuf,
273 rsa, RSA_NO_PADDING);
276 ret = RSA_verify_PKCS1_PSS_mgf1(rsa, tbs,
277 rctx->md, rctx->mgf1md,
278 rctx->tbuf, rctx->saltlen);
286 if (!setup_tbuf(rctx, ctx))
288 rslen = RSA_public_decrypt(siglen, sig, rctx->tbuf,
289 rsa, rctx->pad_mode);
294 if ((rslen != tbslen) || memcmp(tbs, rctx->tbuf, rslen))
301 static int pkey_rsa_encrypt(EVP_PKEY_CTX *ctx,
302 unsigned char *out, size_t *outlen,
303 const unsigned char *in, size_t inlen)
306 RSA_PKEY_CTX *rctx = ctx->data;
308 if (rctx->pad_mode == RSA_PKCS1_OAEP_PADDING) {
309 int klen = RSA_size(ctx->pkey->pkey.rsa);
310 if (!setup_tbuf(rctx, ctx))
312 if (!RSA_padding_add_PKCS1_OAEP_mgf1(rctx->tbuf, klen,
316 rctx->md, rctx->mgf1md))
318 ret = RSA_public_encrypt(klen, rctx->tbuf, out,
319 ctx->pkey->pkey.rsa, RSA_NO_PADDING);
321 ret = RSA_public_encrypt(inlen, in, out, ctx->pkey->pkey.rsa,
330 static int pkey_rsa_decrypt(EVP_PKEY_CTX *ctx,
331 unsigned char *out, size_t *outlen,
332 const unsigned char *in, size_t inlen)
335 RSA_PKEY_CTX *rctx = ctx->data;
337 if (rctx->pad_mode == RSA_PKCS1_OAEP_PADDING) {
338 if (!setup_tbuf(rctx, ctx))
340 ret = RSA_private_decrypt(inlen, in, rctx->tbuf,
341 ctx->pkey->pkey.rsa, RSA_NO_PADDING);
344 ret = RSA_padding_check_PKCS1_OAEP_mgf1(out, ret, rctx->tbuf,
348 rctx->md, rctx->mgf1md);
350 ret = RSA_private_decrypt(inlen, in, out, ctx->pkey->pkey.rsa,
353 *outlen = constant_time_select_s(constant_time_msb_s(ret), *outlen, ret);
354 ret = constant_time_select_int(constant_time_msb(ret), ret, 1);
358 static int check_padding_md(const EVP_MD *md, int padding)
365 mdnid = EVP_MD_type(md);
367 if (padding == RSA_NO_PADDING) {
368 RSAerr(RSA_F_CHECK_PADDING_MD, RSA_R_INVALID_PADDING_MODE);
372 if (padding == RSA_X931_PADDING) {
373 if (RSA_X931_hash_id(mdnid) == -1) {
374 RSAerr(RSA_F_CHECK_PADDING_MD, RSA_R_INVALID_X931_DIGEST);
379 /* List of all supported RSA digests */
398 RSAerr(RSA_F_CHECK_PADDING_MD, RSA_R_INVALID_DIGEST);
407 static int pkey_rsa_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
409 RSA_PKEY_CTX *rctx = ctx->data;
412 case EVP_PKEY_CTRL_RSA_PADDING:
413 if ((p1 >= RSA_PKCS1_PADDING) && (p1 <= RSA_PKCS1_PSS_PADDING)) {
414 if (!check_padding_md(rctx->md, p1))
416 if (p1 == RSA_PKCS1_PSS_PADDING) {
417 if (!(ctx->operation &
418 (EVP_PKEY_OP_SIGN | EVP_PKEY_OP_VERIFY)))
421 rctx->md = EVP_sha1();
422 } else if (pkey_ctx_is_pss(ctx)) {
425 if (p1 == RSA_PKCS1_OAEP_PADDING) {
426 if (!(ctx->operation & EVP_PKEY_OP_TYPE_CRYPT))
429 rctx->md = EVP_sha1();
435 RSAerr(RSA_F_PKEY_RSA_CTRL,
436 RSA_R_ILLEGAL_OR_UNSUPPORTED_PADDING_MODE);
439 case EVP_PKEY_CTRL_GET_RSA_PADDING:
440 *(int *)p2 = rctx->pad_mode;
443 case EVP_PKEY_CTRL_RSA_PSS_SALTLEN:
444 case EVP_PKEY_CTRL_GET_RSA_PSS_SALTLEN:
445 if (rctx->pad_mode != RSA_PKCS1_PSS_PADDING) {
446 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PSS_SALTLEN);
449 if (type == EVP_PKEY_CTRL_GET_RSA_PSS_SALTLEN) {
450 *(int *)p2 = rctx->saltlen;
452 if (p1 < RSA_PSS_SALTLEN_MAX)
454 if (rsa_pss_restricted(rctx)) {
455 if (p1 == RSA_PSS_SALTLEN_AUTO
456 && ctx->operation == EVP_PKEY_OP_VERIFY) {
457 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PSS_SALTLEN);
460 if ((p1 == RSA_PSS_SALTLEN_DIGEST
461 && rctx->min_saltlen > EVP_MD_size(rctx->md))
462 || (p1 >= 0 && p1 < rctx->min_saltlen)) {
463 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_PSS_SALTLEN_TOO_SMALL);
471 case EVP_PKEY_CTRL_RSA_KEYGEN_BITS:
472 if (p1 < RSA_MIN_MODULUS_BITS) {
473 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_KEY_SIZE_TOO_SMALL);
479 case EVP_PKEY_CTRL_RSA_KEYGEN_PUBEXP:
480 if (p2 == NULL || !BN_is_odd((BIGNUM *)p2) || BN_is_one((BIGNUM *)p2)) {
481 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_BAD_E_VALUE);
484 BN_free(rctx->pub_exp);
488 case EVP_PKEY_CTRL_RSA_KEYGEN_PRIMES:
489 if (p1 < RSA_DEFAULT_PRIME_NUM || p1 > RSA_MAX_PRIME_NUM) {
490 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_KEY_PRIME_NUM_INVALID);
496 case EVP_PKEY_CTRL_RSA_OAEP_MD:
497 case EVP_PKEY_CTRL_GET_RSA_OAEP_MD:
498 if (rctx->pad_mode != RSA_PKCS1_OAEP_PADDING) {
499 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PADDING_MODE);
502 if (type == EVP_PKEY_CTRL_GET_RSA_OAEP_MD)
503 *(const EVP_MD **)p2 = rctx->md;
508 case EVP_PKEY_CTRL_MD:
509 if (!check_padding_md(p2, rctx->pad_mode))
511 if (rsa_pss_restricted(rctx)) {
512 if (EVP_MD_type(rctx->md) == EVP_MD_type(p2))
514 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_DIGEST_NOT_ALLOWED);
520 case EVP_PKEY_CTRL_GET_MD:
521 *(const EVP_MD **)p2 = rctx->md;
524 case EVP_PKEY_CTRL_RSA_MGF1_MD:
525 case EVP_PKEY_CTRL_GET_RSA_MGF1_MD:
526 if (rctx->pad_mode != RSA_PKCS1_PSS_PADDING
527 && rctx->pad_mode != RSA_PKCS1_OAEP_PADDING) {
528 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_MGF1_MD);
531 if (type == EVP_PKEY_CTRL_GET_RSA_MGF1_MD) {
533 *(const EVP_MD **)p2 = rctx->mgf1md;
535 *(const EVP_MD **)p2 = rctx->md;
537 if (rsa_pss_restricted(rctx)) {
538 if (EVP_MD_type(rctx->mgf1md) == EVP_MD_type(p2))
540 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_MGF1_DIGEST_NOT_ALLOWED);
547 case EVP_PKEY_CTRL_RSA_OAEP_LABEL:
548 if (rctx->pad_mode != RSA_PKCS1_OAEP_PADDING) {
549 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PADDING_MODE);
552 OPENSSL_free(rctx->oaep_label);
554 rctx->oaep_label = p2;
555 rctx->oaep_labellen = p1;
557 rctx->oaep_label = NULL;
558 rctx->oaep_labellen = 0;
562 case EVP_PKEY_CTRL_GET_RSA_OAEP_LABEL:
563 if (rctx->pad_mode != RSA_PKCS1_OAEP_PADDING) {
564 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PADDING_MODE);
567 *(unsigned char **)p2 = rctx->oaep_label;
568 return rctx->oaep_labellen;
570 case EVP_PKEY_CTRL_DIGESTINIT:
571 case EVP_PKEY_CTRL_PKCS7_SIGN:
572 #ifndef OPENSSL_NO_CMS
573 case EVP_PKEY_CTRL_CMS_SIGN:
577 case EVP_PKEY_CTRL_PKCS7_ENCRYPT:
578 case EVP_PKEY_CTRL_PKCS7_DECRYPT:
579 #ifndef OPENSSL_NO_CMS
580 case EVP_PKEY_CTRL_CMS_DECRYPT:
581 case EVP_PKEY_CTRL_CMS_ENCRYPT:
583 if (!pkey_ctx_is_pss(ctx))
586 case EVP_PKEY_CTRL_PEER_KEY:
587 RSAerr(RSA_F_PKEY_RSA_CTRL,
588 RSA_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
597 static int pkey_rsa_ctrl_str(EVP_PKEY_CTX *ctx,
598 const char *type, const char *value)
601 RSAerr(RSA_F_PKEY_RSA_CTRL_STR, RSA_R_VALUE_MISSING);
604 if (strcmp(type, "rsa_padding_mode") == 0) {
607 if (strcmp(value, "pkcs1") == 0) {
608 pm = RSA_PKCS1_PADDING;
609 } else if (strcmp(value, "sslv23") == 0) {
610 pm = RSA_SSLV23_PADDING;
611 } else if (strcmp(value, "none") == 0) {
613 } else if (strcmp(value, "oeap") == 0) {
614 pm = RSA_PKCS1_OAEP_PADDING;
615 } else if (strcmp(value, "oaep") == 0) {
616 pm = RSA_PKCS1_OAEP_PADDING;
617 } else if (strcmp(value, "x931") == 0) {
618 pm = RSA_X931_PADDING;
619 } else if (strcmp(value, "pss") == 0) {
620 pm = RSA_PKCS1_PSS_PADDING;
622 RSAerr(RSA_F_PKEY_RSA_CTRL_STR, RSA_R_UNKNOWN_PADDING_TYPE);
625 return EVP_PKEY_CTX_set_rsa_padding(ctx, pm);
628 if (strcmp(type, "rsa_pss_saltlen") == 0) {
631 if (!strcmp(value, "digest"))
632 saltlen = RSA_PSS_SALTLEN_DIGEST;
633 else if (!strcmp(value, "max"))
634 saltlen = RSA_PSS_SALTLEN_MAX;
635 else if (!strcmp(value, "auto"))
636 saltlen = RSA_PSS_SALTLEN_AUTO;
638 saltlen = atoi(value);
639 return EVP_PKEY_CTX_set_rsa_pss_saltlen(ctx, saltlen);
642 if (strcmp(type, "rsa_keygen_bits") == 0) {
643 int nbits = atoi(value);
645 return EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, nbits);
648 if (strcmp(type, "rsa_keygen_pubexp") == 0) {
651 BIGNUM *pubexp = NULL;
652 if (!BN_asc2bn(&pubexp, value))
654 ret = EVP_PKEY_CTX_set_rsa_keygen_pubexp(ctx, pubexp);
660 if (strcmp(type, "rsa_keygen_primes") == 0) {
661 int nprimes = atoi(value);
663 return EVP_PKEY_CTX_set_rsa_keygen_primes(ctx, nprimes);
666 if (strcmp(type, "rsa_mgf1_md") == 0)
667 return EVP_PKEY_CTX_md(ctx,
668 EVP_PKEY_OP_TYPE_SIG | EVP_PKEY_OP_TYPE_CRYPT,
669 EVP_PKEY_CTRL_RSA_MGF1_MD, value);
671 if (pkey_ctx_is_pss(ctx)) {
673 if (strcmp(type, "rsa_pss_keygen_mgf1_md") == 0)
674 return EVP_PKEY_CTX_md(ctx, EVP_PKEY_OP_KEYGEN,
675 EVP_PKEY_CTRL_RSA_MGF1_MD, value);
677 if (strcmp(type, "rsa_pss_keygen_md") == 0)
678 return EVP_PKEY_CTX_md(ctx, EVP_PKEY_OP_KEYGEN,
679 EVP_PKEY_CTRL_MD, value);
681 if (strcmp(type, "rsa_pss_keygen_saltlen") == 0) {
682 int saltlen = atoi(value);
684 return EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen(ctx, saltlen);
688 if (strcmp(type, "rsa_oaep_md") == 0)
689 return EVP_PKEY_CTX_md(ctx, EVP_PKEY_OP_TYPE_CRYPT,
690 EVP_PKEY_CTRL_RSA_OAEP_MD, value);
692 if (strcmp(type, "rsa_oaep_label") == 0) {
697 lab = OPENSSL_hexstr2buf(value, &lablen);
700 ret = EVP_PKEY_CTX_set0_rsa_oaep_label(ctx, lab, lablen);
709 /* Set PSS parameters when generating a key, if necessary */
710 static int rsa_set_pss_param(RSA *rsa, EVP_PKEY_CTX *ctx)
712 RSA_PKEY_CTX *rctx = ctx->data;
714 if (!pkey_ctx_is_pss(ctx))
716 /* If all parameters are default values don't set pss */
717 if (rctx->md == NULL && rctx->mgf1md == NULL && rctx->saltlen == -2)
719 rsa->pss = rsa_pss_params_create(rctx->md, rctx->mgf1md,
720 rctx->saltlen == -2 ? 0 : rctx->saltlen);
721 if (rsa->pss == NULL)
726 static int pkey_rsa_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
729 RSA_PKEY_CTX *rctx = ctx->data;
733 if (rctx->pub_exp == NULL) {
734 rctx->pub_exp = BN_new();
735 if (rctx->pub_exp == NULL || !BN_set_word(rctx->pub_exp, RSA_F4))
741 if (ctx->pkey_gencb) {
742 pcb = BN_GENCB_new();
747 evp_pkey_set_cb_translate(pcb, ctx);
751 ret = RSA_generate_multi_prime_key(rsa, rctx->nbits, rctx->primes,
754 if (ret > 0 && !rsa_set_pss_param(rsa, ctx)) {
759 EVP_PKEY_assign(pkey, ctx->pmeth->pkey_id, rsa);
765 static const EVP_PKEY_METHOD rsa_pkey_meth = {
767 EVP_PKEY_FLAG_AUTOARGLEN,
784 pkey_rsa_verifyrecover,
800 const EVP_PKEY_METHOD *rsa_pkey_method(void)
802 return &rsa_pkey_meth;
806 * Called for PSS sign or verify initialisation: checks PSS parameter
807 * sanity and sets any restrictions on key usage.
810 static int pkey_pss_init(EVP_PKEY_CTX *ctx)
813 RSA_PKEY_CTX *rctx = ctx->data;
815 const EVP_MD *mgf1md;
816 int min_saltlen, max_saltlen;
818 /* Should never happen */
819 if (!pkey_ctx_is_pss(ctx))
821 rsa = ctx->pkey->pkey.rsa;
822 /* If no restrictions just return */
823 if (rsa->pss == NULL)
825 /* Get and check parameters */
826 if (!rsa_pss_get_param(rsa->pss, &md, &mgf1md, &min_saltlen))
829 /* See if minimum salt length exceeds maximum possible */
830 max_saltlen = RSA_size(rsa) - EVP_MD_size(md);
831 if ((RSA_bits(rsa) & 0x7) == 1)
833 if (min_saltlen > max_saltlen) {
834 RSAerr(RSA_F_PKEY_PSS_INIT, RSA_R_INVALID_SALT_LENGTH);
838 rctx->min_saltlen = min_saltlen;
841 * Set PSS restrictions as defaults: we can then block any attempt to
842 * use invalid values in pkey_rsa_ctrl
846 rctx->mgf1md = mgf1md;
847 rctx->saltlen = min_saltlen;
852 static const EVP_PKEY_METHOD rsa_pss_pkey_meth = {
854 EVP_PKEY_FLAG_AUTOARGLEN,
870 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
876 const EVP_PKEY_METHOD *rsa_pss_pkey_method(void)
878 return &rsa_pss_pkey_meth;