cloud-agent/cms/lib/libressl_pkey.c
2017-06-29 11:40:48 +02:00

698 lines
20 KiB
C

/* crypto/rsa/rsa_ameth.c */
/*
* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
* 2006.
*/
/* ====================================================================
* Copyright (c) 2006 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* licensing@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
#include "cryptlib.h"
#include <openssl/asn1t.h>
#include <openssl/x509.h>
#include <openssl/err.h>
#include <openssl/rsa.h>
#include <openssl/evp.h>
#include <openssl/x509v3.h>
#include "cms.h"
#include "cms_lcl.h"
#include "evp_locl.h"
#include "asn1_locl.h"
#include "libressl_evp.h"
/* RSA pkey context structure */
typedef struct {
/* Key gen parameters */
int nbits;
BIGNUM *pub_exp;
/* Keygen callback info */
int gentmp[2];
/* RSA padding mode */
int pad_mode;
/* message digest */
const EVP_MD *md;
/* message digest for MGF1 */
const EVP_MD *mgf1md;
/* PSS/OAEP salt length */
int saltlen;
/* Temp buffer */
unsigned char *tbuf;
} RSA_PKEY_CTX;
static int pkey_rsa_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2);
static int pkey_rsa_ctrl_str(EVP_PKEY_CTX *ctx, const char *type,
const char *value);
static int rsa_cms_sign(CMS_SignerInfo *si);
static int rsa_cms_verify(CMS_SignerInfo *si);
static int rsa_cms_decrypt(CMS_RecipientInfo *ri);
static int rsa_cms_encrypt(CMS_RecipientInfo *ri);
int libressl_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
{
X509_ALGOR *alg = NULL;
if (pkey->ameth->pkey_id != EVP_PKEY_RSA)
return -2;
switch (op) {
case ASN1_PKEY_CTRL_CMS_SIGN:
if (arg1 == 0)
return rsa_cms_sign(arg2);
else if (arg1 == 1)
return rsa_cms_verify(arg2);
break;
case ASN1_PKEY_CTRL_CMS_ENVELOPE:
if (arg1 == 0)
return rsa_cms_encrypt(arg2);
else if (arg1 == 1)
return rsa_cms_decrypt(arg2);
break;
case ASN1_PKEY_CTRL_CMS_RI_TYPE:
*(int *)arg2 = CMS_RECIPINFO_TRANS;
return 1;
default:
return -2;
}
if (alg)
X509_ALGOR_set0(alg, OBJ_nid2obj(NID_rsaEncryption), V_ASN1_NULL, 0);
return 1;
}
int libressl_pkey_ctx_ctrl(EVP_PKEY_CTX *ctx, int keytype, int optype,
int cmd, int p1, void *p2)
{
int ret;
if (!ctx || !ctx->pmeth || !ctx->pmeth->ctrl) {
EVPerr(EVP_F_EVP_PKEY_CTX_CTRL, EVP_R_COMMAND_NOT_SUPPORTED);
return -2;
}
if ((keytype != -1) && (ctx->pmeth->pkey_id != keytype))
return -1;
if (ctx->operation == EVP_PKEY_OP_UNDEFINED) {
EVPerr(EVP_F_EVP_PKEY_CTX_CTRL, EVP_R_NO_OPERATION_SET);
return -1;
}
if ((optype != -1) && !(ctx->operation & optype)) {
EVPerr(EVP_F_EVP_PKEY_CTX_CTRL, EVP_R_INVALID_OPERATION);
return -1;
}
if (ctx->pmeth->pkey_id != EVP_PKEY_RSA)
return -1;
ret = pkey_rsa_ctrl(ctx, cmd, p1, p2);
if (ret == -2)
EVPerr(EVP_F_EVP_PKEY_CTX_CTRL, EVP_R_COMMAND_NOT_SUPPORTED);
return ret;
}
static int check_padding_md(const EVP_MD *md, int padding)
{
if (!md)
return 1;
if (padding == RSA_NO_PADDING) {
RSAerr(RSA_F_CHECK_PADDING_MD, RSA_R_INVALID_PADDING_MODE);
return 0;
}
if (padding == RSA_X931_PADDING) {
if (RSA_X931_hash_id(EVP_MD_type(md)) == -1) {
RSAerr(RSA_F_CHECK_PADDING_MD, RSA_R_INVALID_X931_DIGEST);
return 0;
}
return 1;
}
return 1;
}
static int pkey_rsa_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
{
RSA_PKEY_CTX *rctx = ctx->data;
switch (type) {
case EVP_PKEY_CTRL_RSA_PADDING:
if ((p1 >= RSA_PKCS1_PADDING) && (p1 <= RSA_PKCS1_PSS_PADDING)) {
if (!check_padding_md(rctx->md, p1))
return 0;
if (p1 == RSA_PKCS1_PSS_PADDING) {
if (!(ctx->operation &
(EVP_PKEY_OP_SIGN | EVP_PKEY_OP_VERIFY)))
goto bad_pad;
if (!rctx->md)
rctx->md = EVP_sha1();
} else
goto bad_pad;
rctx->pad_mode = p1;
return 1;
}
bad_pad:
RSAerr(RSA_F_PKEY_RSA_CTRL,
RSA_R_ILLEGAL_OR_UNSUPPORTED_PADDING_MODE);
return -2;
case EVP_PKEY_CTRL_GET_RSA_PADDING:
*(int *)p2 = rctx->pad_mode;
return 1;
case EVP_PKEY_CTRL_RSA_PSS_SALTLEN:
case EVP_PKEY_CTRL_GET_RSA_PSS_SALTLEN:
if (rctx->pad_mode != RSA_PKCS1_PSS_PADDING) {
RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_PSS_SALTLEN);
return -2;
}
if (type == EVP_PKEY_CTRL_GET_RSA_PSS_SALTLEN)
*(int *)p2 = rctx->saltlen;
else {
if (p1 < -2)
return -2;
rctx->saltlen = p1;
}
return 1;
case EVP_PKEY_CTRL_RSA_KEYGEN_BITS:
if (p1 < 256) {
RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_KEYBITS);
return -2;
}
rctx->nbits = p1;
return 1;
case EVP_PKEY_CTRL_RSA_KEYGEN_PUBEXP:
if (p2 == NULL || !BN_is_odd((BIGNUM *)p2) || BN_is_one((BIGNUM *)p2)) {
RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_BAD_E_VALUE);
return -2;
}
BN_free(rctx->pub_exp);
rctx->pub_exp = p2;
return 1;
case EVP_PKEY_CTRL_MD:
if (!check_padding_md(p2, rctx->pad_mode))
return 0;
rctx->md = p2;
return 1;
case EVP_PKEY_CTRL_GET_MD:
*(const EVP_MD **)p2 = rctx->md;
return 1;
case EVP_PKEY_CTRL_RSA_MGF1_MD:
case EVP_PKEY_CTRL_GET_RSA_MGF1_MD:
if (rctx->pad_mode != RSA_PKCS1_PSS_PADDING) {
RSAerr(RSA_F_PKEY_RSA_CTRL, RSA_R_INVALID_MGF1_MD);
return -2;
}
if (type == EVP_PKEY_CTRL_GET_RSA_MGF1_MD) {
if (rctx->mgf1md)
*(const EVP_MD **)p2 = rctx->mgf1md;
else
*(const EVP_MD **)p2 = rctx->md;
} else
rctx->mgf1md = p2;
return 1;
case EVP_PKEY_CTRL_DIGESTINIT:
case EVP_PKEY_CTRL_PKCS7_ENCRYPT:
case EVP_PKEY_CTRL_PKCS7_DECRYPT:
case EVP_PKEY_CTRL_PKCS7_SIGN:
return 1;
case EVP_PKEY_CTRL_CMS_DECRYPT:
case EVP_PKEY_CTRL_CMS_ENCRYPT:
case EVP_PKEY_CTRL_CMS_SIGN:
return 1;
case EVP_PKEY_CTRL_PEER_KEY:
RSAerr(RSA_F_PKEY_RSA_CTRL,
RSA_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
return -2;
default:
return -2;
}
}
int libressl_pkey_ctx_ctrl_str(EVP_PKEY_CTX *ctx, const char *name,
const char *value)
{
if (!ctx || !ctx->pmeth || !ctx->pmeth->ctrl_str) {
EVPerr(EVP_F_EVP_PKEY_CTX_CTRL_STR, EVP_R_COMMAND_NOT_SUPPORTED);
return -2;
}
if (!strcmp(name, "digest")) {
const EVP_MD *md;
if (!value || !(md = EVP_get_digestbyname(value))) {
EVPerr(EVP_F_EVP_PKEY_CTX_CTRL_STR, EVP_R_INVALID_DIGEST);
return 0;
}
return EVP_PKEY_CTX_set_signature_md(ctx, md);
}
return pkey_rsa_ctrl_str(ctx, name, value);
}
static int pkey_rsa_ctrl_str(EVP_PKEY_CTX *ctx, const char *type,
const char *value)
{
if (!value) {
RSAerr(RSA_F_PKEY_RSA_CTRL_STR, RSA_R_VALUE_MISSING);
return 0;
}
if (!strcmp(type, "rsa_padding_mode")) {
int pm;
if (!strcmp(value, "pkcs1"))
pm = RSA_PKCS1_PADDING;
else if (!strcmp(value, "sslv23"))
pm = RSA_SSLV23_PADDING;
else if (!strcmp(value, "none"))
pm = RSA_NO_PADDING;
else if (!strcmp(value, "x931"))
pm = RSA_X931_PADDING;
else if (!strcmp(value, "pss"))
pm = RSA_PKCS1_PSS_PADDING;
else {
RSAerr(RSA_F_PKEY_RSA_CTRL_STR, RSA_R_UNKNOWN_PADDING_TYPE);
return -2;
}
return EVP_PKEY_CTX_set_rsa_padding(ctx, pm);
}
if (!strcmp(type, "rsa_pss_saltlen")) {
int saltlen;
saltlen = atoi(value);
return EVP_PKEY_CTX_set_rsa_pss_saltlen(ctx, saltlen);
}
if (!strcmp(type, "rsa_keygen_bits")) {
int nbits;
nbits = atoi(value);
return EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, nbits);
}
if (!strcmp(type, "rsa_keygen_pubexp")) {
int ret;
BIGNUM *pubexp = NULL;
if (!BN_asc2bn(&pubexp, value))
return 0;
ret = EVP_PKEY_CTX_set_rsa_keygen_pubexp(ctx, pubexp);
if (ret <= 0)
BN_free(pubexp);
return ret;
}
if (!strcmp(type, "rsa_mgf1_md")) {
const EVP_MD *md;
if (!(md = EVP_get_digestbyname(value))) {
return 0;
}
return EVP_PKEY_CTX_set_rsa_mgf1_md(ctx, md);
}
return -2;
}
/* Given an MGF1 Algorithm ID decode to an Algorithm Identifier */
static X509_ALGOR *rsa_mgf1_decode(X509_ALGOR *alg)
{
const unsigned char *p;
int plen;
if (alg == NULL || alg->parameter == NULL)
return NULL;
if (OBJ_obj2nid(alg->algorithm) != NID_mgf1)
return NULL;
if (alg->parameter->type != V_ASN1_SEQUENCE)
return NULL;
p = alg->parameter->value.sequence->data;
plen = alg->parameter->value.sequence->length;
return d2i_X509_ALGOR(NULL, &p, plen);
}
static RSA_PSS_PARAMS *rsa_pss_decode(const X509_ALGOR *alg,
X509_ALGOR **pmaskHash)
{
const unsigned char *p;
int plen;
RSA_PSS_PARAMS *pss;
*pmaskHash = NULL;
if (!alg->parameter || alg->parameter->type != V_ASN1_SEQUENCE)
return NULL;
p = alg->parameter->value.sequence->data;
plen = alg->parameter->value.sequence->length;
pss = d2i_RSA_PSS_PARAMS(NULL, &p, plen);
if (!pss)
return NULL;
*pmaskHash = rsa_mgf1_decode(pss->maskGenAlgorithm);
return pss;
}
/* allocate and set algorithm ID from EVP_MD, default SHA1 */
static int rsa_md_to_algor(X509_ALGOR **palg, const EVP_MD *md)
{
if (EVP_MD_type(md) == NID_sha1)
return 1;
*palg = X509_ALGOR_new();
if (!*palg)
return 0;
X509_ALGOR_set_md(*palg, md);
return 1;
}
/* Allocate and set MGF1 algorithm ID from EVP_MD */
static int rsa_md_to_mgf1(X509_ALGOR **palg, const EVP_MD *mgf1md)
{
X509_ALGOR *algtmp = NULL;
ASN1_STRING *stmp = NULL;
*palg = NULL;
if (EVP_MD_type(mgf1md) == NID_sha1)
return 1;
/* need to embed algorithm ID inside another */
if (!rsa_md_to_algor(&algtmp, mgf1md))
goto err;
if (!ASN1_item_pack(algtmp, ASN1_ITEM_rptr(X509_ALGOR), &stmp))
goto err;
*palg = X509_ALGOR_new();
if (!*palg)
goto err;
X509_ALGOR_set0(*palg, OBJ_nid2obj(NID_mgf1), V_ASN1_SEQUENCE, stmp);
stmp = NULL;
err:
if (stmp)
ASN1_STRING_free(stmp);
if (algtmp)
X509_ALGOR_free(algtmp);
if (*palg)
return 1;
return 0;
}
/* convert algorithm ID to EVP_MD, default SHA1 */
static const EVP_MD *rsa_algor_to_md(X509_ALGOR *alg)
{
const EVP_MD *md;
if (!alg)
return EVP_sha1();
md = EVP_get_digestbyobj(alg->algorithm);
return md;
}
/* convert MGF1 algorithm ID to EVP_MD, default SHA1 */
static const EVP_MD *rsa_mgf1_to_md(X509_ALGOR *alg, X509_ALGOR *maskHash)
{
const EVP_MD *md;
if (!alg)
return EVP_sha1();
/* Check mask and lookup mask hash algorithm */
if (OBJ_obj2nid(alg->algorithm) != NID_mgf1) {
return NULL;
}
if (!maskHash) {
return NULL;
}
md = EVP_get_digestbyobj(maskHash->algorithm);
return md;
}
/*
* Convert EVP_PKEY_CTX is PSS mode into corresponding algorithm parameter,
* suitable for setting an AlgorithmIdentifier.
*/
static ASN1_STRING *rsa_ctx_to_pss(EVP_PKEY_CTX *pkctx)
{
const EVP_MD *sigmd, *mgf1md;
RSA_PSS_PARAMS *pss = NULL;
ASN1_STRING *os = NULL;
EVP_PKEY *pk = EVP_PKEY_CTX_get0_pkey(pkctx);
int saltlen, rv = 0;
if (EVP_PKEY_CTX_get_signature_md(pkctx, &sigmd) <= 0)
goto err;
if (EVP_PKEY_CTX_get_rsa_mgf1_md(pkctx, &mgf1md) <= 0)
goto err;
if (!EVP_PKEY_CTX_get_rsa_pss_saltlen(pkctx, &saltlen))
goto err;
if (saltlen == -1)
saltlen = EVP_MD_size(sigmd);
else if (saltlen == -2) {
saltlen = EVP_PKEY_size(pk) - EVP_MD_size(sigmd) - 2;
if (((EVP_PKEY_bits(pk) - 1) & 0x7) == 0)
saltlen--;
}
pss = RSA_PSS_PARAMS_new();
if (!pss)
goto err;
if (saltlen != 20) {
pss->saltLength = ASN1_INTEGER_new();
if (!pss->saltLength)
goto err;
if (!ASN1_INTEGER_set(pss->saltLength, saltlen))
goto err;
}
if (!rsa_md_to_algor(&pss->hashAlgorithm, sigmd))
goto err;
if (!rsa_md_to_mgf1(&pss->maskGenAlgorithm, mgf1md))
goto err;
/* Finally create string with pss parameter encoding. */
if (!ASN1_item_pack(pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), &os))
goto err;
rv = 1;
err:
if (pss)
RSA_PSS_PARAMS_free(pss);
if (rv)
return os;
if (os)
ASN1_STRING_free(os);
return NULL;
}
/*
* From PSS AlgorithmIdentifier set public key parameters. If pkey isn't NULL
* then the EVP_MD_CTX is setup and initalised. If it is NULL parameters are
* passed to pkctx instead.
*/
static int rsa_pss_to_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pkctx,
X509_ALGOR *sigalg, EVP_PKEY *pkey)
{
int rv = -1;
int saltlen;
const EVP_MD *mgf1md = NULL, *md = NULL;
RSA_PSS_PARAMS *pss;
X509_ALGOR *maskHash;
/* Sanity check: make sure it is PSS */
if (OBJ_obj2nid(sigalg->algorithm) != NID_rsassaPss) {
return -1;
}
/* Decode PSS parameters */
pss = rsa_pss_decode(sigalg, &maskHash);
if (pss == NULL) {
goto err;
}
mgf1md = rsa_mgf1_to_md(pss->maskGenAlgorithm, maskHash);
if (!mgf1md)
goto err;
md = rsa_algor_to_md(pss->hashAlgorithm);
if (!md)
goto err;
if (pss->saltLength) {
saltlen = ASN1_INTEGER_get(pss->saltLength);
/*
* Could perform more salt length sanity checks but the main RSA
* routines will trap other invalid values anyway.
*/
if (saltlen < 0) {
goto err;
}
} else
saltlen = 20;
/*
* low-level routines support only trailer field 0xbc (value 1) and
* PKCS#1 says we should reject any other value anyway.
*/
if (pss->trailerField && ASN1_INTEGER_get(pss->trailerField) != 1) {
goto err;
}
/* We have all parameters now set up context */
if (pkey) {
if (!EVP_DigestVerifyInit(ctx, &pkctx, md, NULL, pkey))
goto err;
} else {
const EVP_MD *checkmd;
if (EVP_PKEY_CTX_get_signature_md(pkctx, &checkmd) <= 0)
goto err;
if (EVP_MD_type(md) != EVP_MD_type(checkmd)) {
goto err;
}
}
if (EVP_PKEY_CTX_set_rsa_padding(pkctx, RSA_PKCS1_PSS_PADDING) <= 0)
goto err;
if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkctx, saltlen) <= 0)
goto err;
if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkctx, mgf1md) <= 0)
goto err;
/* Carry on */
rv = 1;
err:
RSA_PSS_PARAMS_free(pss);
if (maskHash)
X509_ALGOR_free(maskHash);
return rv;
}
static int rsa_cms_verify(CMS_SignerInfo *si)
{
int nid, nid2;
X509_ALGOR *alg;
EVP_PKEY_CTX *pkctx = CMS_SignerInfo_get0_pkey_ctx(si);
CMS_SignerInfo_get0_algs(si, NULL, NULL, NULL, &alg);
nid = OBJ_obj2nid(alg->algorithm);
if (nid == NID_rsaEncryption)
return 1;
if (nid == NID_rsassaPss)
return rsa_pss_to_ctx(NULL, pkctx, alg, NULL);
/* Workaround for some implementation that use a signature OID */
if (OBJ_find_sigid_algs(nid, NULL, &nid2)) {
if (nid2 == NID_rsaEncryption)
return 1;
}
return 0;
}
static int rsa_cms_sign(CMS_SignerInfo *si)
{
int pad_mode = RSA_PKCS1_PADDING;
X509_ALGOR *alg;
EVP_PKEY_CTX *pkctx = CMS_SignerInfo_get0_pkey_ctx(si);
ASN1_STRING *os = NULL;
CMS_SignerInfo_get0_algs(si, NULL, NULL, NULL, &alg);
if (pkctx) {
if (EVP_PKEY_CTX_get_rsa_padding(pkctx, &pad_mode) <= 0)
return 0;
}
if (pad_mode == RSA_PKCS1_PADDING) {
X509_ALGOR_set0(alg, OBJ_nid2obj(NID_rsaEncryption), V_ASN1_NULL, 0);
return 1;
}
/* We don't support it */
if (pad_mode != RSA_PKCS1_PSS_PADDING)
return 0;
os = rsa_ctx_to_pss(pkctx);
if (!os)
return 0;
X509_ALGOR_set0(alg, OBJ_nid2obj(NID_rsassaPss), V_ASN1_SEQUENCE, os);
return 1;
}
static int rsa_cms_decrypt(CMS_RecipientInfo *ri)
{
EVP_PKEY_CTX *pkctx;
X509_ALGOR *cmsalg;
int nid;
pkctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
if (!pkctx)
return 0;
if (!CMS_RecipientInfo_ktri_get0_algs(ri, NULL, NULL, &cmsalg))
return -1;
nid = OBJ_obj2nid(cmsalg->algorithm);
if (nid == NID_rsaEncryption)
return 1;
return -1;
}
static int rsa_cms_encrypt(CMS_RecipientInfo *ri)
{
X509_ALGOR *alg;
EVP_PKEY_CTX *pkctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
int pad_mode = RSA_PKCS1_PADDING;
CMS_RecipientInfo_ktri_get0_algs(ri, NULL, NULL, &alg);
if (pkctx) {
if (EVP_PKEY_CTX_get_rsa_padding(pkctx, &pad_mode) <= 0)
return 0;
}
if (pad_mode == RSA_PKCS1_PADDING) {
X509_ALGOR_set0(alg, OBJ_nid2obj(NID_rsaEncryption), V_ASN1_NULL, 0);
return 1;
}
return 0;
}