2 * Copyright 2006-2020 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 */
400 RSAerr(RSA_F_CHECK_PADDING_MD, RSA_R_INVALID_DIGEST);
409 static int pkey_rsa_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
411 RSA_PKEY_CTX *rctx = ctx->data;
414 case EVP_PKEY_CTRL_RSA_PADDING:
415 if ((p1 >= RSA_PKCS1_PADDING) && (p1 <= RSA_PKCS1_PSS_PADDING)) {
416 if (!check_padding_md(rctx->md, p1))
418 if (p1 == RSA_PKCS1_PSS_PADDING) {
419 if (!(ctx->operation &
420 (EVP_PKEY_OP_SIGN | EVP_PKEY_OP_VERIFY)))
423 rctx->md = EVP_sha1();
424 } else if (pkey_ctx_is_pss(ctx)) {
427 if (p1 == RSA_PKCS1_OAEP_PADDING) {
428 if (!(ctx->operation & EVP_PKEY_OP_TYPE_CRYPT))
431 rctx->md = EVP_sha1();
437 RSAerr(RSA_F_PKEY_RSA_CTRL,
438 RSA_R_ILLEGAL_OR_UNSUPPORTED_PADDING_MODE);
441 case EVP_PKEY_CTRL_GET_RSA_PADDING:
442 *(int *)p2 = rctx->pad_mode;
445 case EVP_PKEY_CTRL_RSA_PSS_SALTLEN:
446 case EVP_PKEY_CTRL_GET_RSA_PSS_SALTLEN:
447 if (rctx->pad_mode != RSA_PKCS1_PSS_PADDING) {
448 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PSS_SALTLEN);
451 if (type == EVP_PKEY_CTRL_GET_RSA_PSS_SALTLEN) {
452 *(int *)p2 = rctx->saltlen;
454 if (p1 < RSA_PSS_SALTLEN_MAX)
456 if (rsa_pss_restricted(rctx)) {
457 if (p1 == RSA_PSS_SALTLEN_AUTO
458 && ctx->operation == EVP_PKEY_OP_VERIFY) {
459 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PSS_SALTLEN);
462 if ((p1 == RSA_PSS_SALTLEN_DIGEST
463 && rctx->min_saltlen > EVP_MD_size(rctx->md))
464 || (p1 >= 0 && p1 < rctx->min_saltlen)) {
465 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_PSS_SALTLEN_TOO_SMALL);
473 case EVP_PKEY_CTRL_RSA_KEYGEN_BITS:
474 if (p1 < RSA_MIN_MODULUS_BITS) {
475 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_KEY_SIZE_TOO_SMALL);
481 case EVP_PKEY_CTRL_RSA_KEYGEN_PUBEXP:
482 if (p2 == NULL || !BN_is_odd((BIGNUM *)p2) || BN_is_one((BIGNUM *)p2)) {
483 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_BAD_E_VALUE);
486 BN_free(rctx->pub_exp);
490 case EVP_PKEY_CTRL_RSA_KEYGEN_PRIMES:
491 if (p1 < RSA_DEFAULT_PRIME_NUM || p1 > RSA_MAX_PRIME_NUM) {
492 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_KEY_PRIME_NUM_INVALID);
498 case EVP_PKEY_CTRL_RSA_OAEP_MD:
499 case EVP_PKEY_CTRL_GET_RSA_OAEP_MD:
500 if (rctx->pad_mode != RSA_PKCS1_OAEP_PADDING) {
501 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PADDING_MODE);
504 if (type == EVP_PKEY_CTRL_GET_RSA_OAEP_MD)
505 *(const EVP_MD **)p2 = rctx->md;
510 case EVP_PKEY_CTRL_MD:
511 if (!check_padding_md(p2, rctx->pad_mode))
513 if (rsa_pss_restricted(rctx)) {
514 if (EVP_MD_type(rctx->md) == EVP_MD_type(p2))
516 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_DIGEST_NOT_ALLOWED);
522 case EVP_PKEY_CTRL_GET_MD:
523 *(const EVP_MD **)p2 = rctx->md;
526 case EVP_PKEY_CTRL_RSA_MGF1_MD:
527 case EVP_PKEY_CTRL_GET_RSA_MGF1_MD:
528 if (rctx->pad_mode != RSA_PKCS1_PSS_PADDING
529 && rctx->pad_mode != RSA_PKCS1_OAEP_PADDING) {
530 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_MGF1_MD);
533 if (type == EVP_PKEY_CTRL_GET_RSA_MGF1_MD) {
535 *(const EVP_MD **)p2 = rctx->mgf1md;
537 *(const EVP_MD **)p2 = rctx->md;
539 if (rsa_pss_restricted(rctx)) {
540 if (EVP_MD_type(rctx->mgf1md) == EVP_MD_type(p2))
542 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_MGF1_DIGEST_NOT_ALLOWED);
549 case EVP_PKEY_CTRL_RSA_OAEP_LABEL:
550 if (rctx->pad_mode != RSA_PKCS1_OAEP_PADDING) {
551 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PADDING_MODE);
554 OPENSSL_free(rctx->oaep_label);
556 rctx->oaep_label = p2;
557 rctx->oaep_labellen = p1;
559 rctx->oaep_label = NULL;
560 rctx->oaep_labellen = 0;
564 case EVP_PKEY_CTRL_GET_RSA_OAEP_LABEL:
565 if (rctx->pad_mode != RSA_PKCS1_OAEP_PADDING) {
566 RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PADDING_MODE);
569 *(unsigned char **)p2 = rctx->oaep_label;
570 return rctx->oaep_labellen;
572 case EVP_PKEY_CTRL_DIGESTINIT:
573 case EVP_PKEY_CTRL_PKCS7_SIGN:
574 #ifndef OPENSSL_NO_CMS
575 case EVP_PKEY_CTRL_CMS_SIGN:
579 case EVP_PKEY_CTRL_PKCS7_ENCRYPT:
580 case EVP_PKEY_CTRL_PKCS7_DECRYPT:
581 #ifndef OPENSSL_NO_CMS
582 case EVP_PKEY_CTRL_CMS_DECRYPT:
583 case EVP_PKEY_CTRL_CMS_ENCRYPT:
585 if (!pkey_ctx_is_pss(ctx))
588 case EVP_PKEY_CTRL_PEER_KEY:
589 RSAerr(RSA_F_PKEY_RSA_CTRL,
590 RSA_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
599 static int pkey_rsa_ctrl_str(EVP_PKEY_CTX *ctx,
600 const char *type, const char *value)
603 RSAerr(RSA_F_PKEY_RSA_CTRL_STR, RSA_R_VALUE_MISSING);
606 if (strcmp(type, "rsa_padding_mode") == 0) {
609 if (strcmp(value, "pkcs1") == 0) {
610 pm = RSA_PKCS1_PADDING;
611 } else if (strcmp(value, "sslv23") == 0) {
612 pm = RSA_SSLV23_PADDING;
613 } else if (strcmp(value, "none") == 0) {
615 } else if (strcmp(value, "oeap") == 0) {
616 pm = RSA_PKCS1_OAEP_PADDING;
617 } else if (strcmp(value, "oaep") == 0) {
618 pm = RSA_PKCS1_OAEP_PADDING;
619 } else if (strcmp(value, "x931") == 0) {
620 pm = RSA_X931_PADDING;
621 } else if (strcmp(value, "pss") == 0) {
622 pm = RSA_PKCS1_PSS_PADDING;
624 RSAerr(RSA_F_PKEY_RSA_CTRL_STR, RSA_R_UNKNOWN_PADDING_TYPE);
627 return EVP_PKEY_CTX_set_rsa_padding(ctx, pm);
630 if (strcmp(type, "rsa_pss_saltlen") == 0) {
633 if (!strcmp(value, "digest"))
634 saltlen = RSA_PSS_SALTLEN_DIGEST;
635 else if (!strcmp(value, "max"))
636 saltlen = RSA_PSS_SALTLEN_MAX;
637 else if (!strcmp(value, "auto"))
638 saltlen = RSA_PSS_SALTLEN_AUTO;
640 saltlen = atoi(value);
641 return EVP_PKEY_CTX_set_rsa_pss_saltlen(ctx, saltlen);
644 if (strcmp(type, "rsa_keygen_bits") == 0) {
645 int nbits = atoi(value);
647 return EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, nbits);
650 if (strcmp(type, "rsa_keygen_pubexp") == 0) {
653 BIGNUM *pubexp = NULL;
654 if (!BN_asc2bn(&pubexp, value))
656 ret = EVP_PKEY_CTX_set_rsa_keygen_pubexp(ctx, pubexp);
662 if (strcmp(type, "rsa_keygen_primes") == 0) {
663 int nprimes = atoi(value);
665 return EVP_PKEY_CTX_set_rsa_keygen_primes(ctx, nprimes);
668 if (strcmp(type, "rsa_mgf1_md") == 0)
669 return EVP_PKEY_CTX_md(ctx,
670 EVP_PKEY_OP_TYPE_SIG | EVP_PKEY_OP_TYPE_CRYPT,
671 EVP_PKEY_CTRL_RSA_MGF1_MD, value);
673 if (pkey_ctx_is_pss(ctx)) {
675 if (strcmp(type, "rsa_pss_keygen_mgf1_md") == 0)
676 return EVP_PKEY_CTX_md(ctx, EVP_PKEY_OP_KEYGEN,
677 EVP_PKEY_CTRL_RSA_MGF1_MD, value);
679 if (strcmp(type, "rsa_pss_keygen_md") == 0)
680 return EVP_PKEY_CTX_md(ctx, EVP_PKEY_OP_KEYGEN,
681 EVP_PKEY_CTRL_MD, value);
683 if (strcmp(type, "rsa_pss_keygen_saltlen") == 0) {
684 int saltlen = atoi(value);
686 return EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen(ctx, saltlen);
690 if (strcmp(type, "rsa_oaep_md") == 0)
691 return EVP_PKEY_CTX_md(ctx, EVP_PKEY_OP_TYPE_CRYPT,
692 EVP_PKEY_CTRL_RSA_OAEP_MD, value);
694 if (strcmp(type, "rsa_oaep_label") == 0) {
699 lab = OPENSSL_hexstr2buf(value, &lablen);
702 ret = EVP_PKEY_CTX_set0_rsa_oaep_label(ctx, lab, lablen);
711 /* Set PSS parameters when generating a key, if necessary */
712 static int rsa_set_pss_param(RSA *rsa, EVP_PKEY_CTX *ctx)
714 RSA_PKEY_CTX *rctx = ctx->data;
716 if (!pkey_ctx_is_pss(ctx))
718 /* If all parameters are default values don't set pss */
719 if (rctx->md == NULL && rctx->mgf1md == NULL && rctx->saltlen == -2)
721 rsa->pss = rsa_pss_params_create(rctx->md, rctx->mgf1md,
722 rctx->saltlen == -2 ? 0 : rctx->saltlen);
723 if (rsa->pss == NULL)
728 static int pkey_rsa_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
731 RSA_PKEY_CTX *rctx = ctx->data;
735 if (rctx->pub_exp == NULL) {
736 rctx->pub_exp = BN_new();
737 if (rctx->pub_exp == NULL || !BN_set_word(rctx->pub_exp, RSA_F4))
743 if (ctx->pkey_gencb) {
744 pcb = BN_GENCB_new();
749 evp_pkey_set_cb_translate(pcb, ctx);
753 ret = RSA_generate_multi_prime_key(rsa, rctx->nbits, rctx->primes,
756 if (ret > 0 && !rsa_set_pss_param(rsa, ctx)) {
761 EVP_PKEY_assign(pkey, ctx->pmeth->pkey_id, rsa);
767 static const EVP_PKEY_METHOD rsa_pkey_meth = {
769 EVP_PKEY_FLAG_AUTOARGLEN,
786 pkey_rsa_verifyrecover,
802 const EVP_PKEY_METHOD *rsa_pkey_method(void)
804 return &rsa_pkey_meth;
808 * Called for PSS sign or verify initialisation: checks PSS parameter
809 * sanity and sets any restrictions on key usage.
812 static int pkey_pss_init(EVP_PKEY_CTX *ctx)
815 RSA_PKEY_CTX *rctx = ctx->data;
817 const EVP_MD *mgf1md;
818 int min_saltlen, max_saltlen;
820 /* Should never happen */
821 if (!pkey_ctx_is_pss(ctx))
823 rsa = ctx->pkey->pkey.rsa;
824 /* If no restrictions just return */
825 if (rsa->pss == NULL)
827 /* Get and check parameters */
828 if (!rsa_pss_get_param(rsa->pss, &md, &mgf1md, &min_saltlen))
831 /* See if minimum salt length exceeds maximum possible */
832 max_saltlen = RSA_size(rsa) - EVP_MD_size(md);
833 if ((RSA_bits(rsa) & 0x7) == 1)
835 if (min_saltlen > max_saltlen) {
836 RSAerr(RSA_F_PKEY_PSS_INIT, RSA_R_INVALID_SALT_LENGTH);
840 rctx->min_saltlen = min_saltlen;
843 * Set PSS restrictions as defaults: we can then block any attempt to
844 * use invalid values in pkey_rsa_ctrl
848 rctx->mgf1md = mgf1md;
849 rctx->saltlen = min_saltlen;
854 static const EVP_PKEY_METHOD rsa_pss_pkey_meth = {
856 EVP_PKEY_FLAG_AUTOARGLEN,
872 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
878 const EVP_PKEY_METHOD *rsa_pss_pkey_method(void)
880 return &rsa_pss_pkey_meth;