rsa_ameth.c
/*
* Copyright 2006-2023 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/*
* RSA low level APIs are deprecated for public use, but still ok for
* internal use.
*/
#include "internal/deprecated.h"
#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/asn1t.h>
#include <openssl/x509.h>
#include <openssl/bn.h>
#include <openssl/core_names.h>
#include <openssl/param_build.h>
#include "crypto/asn1.h"
#include "crypto/evp.h"
#include "crypto/rsa.h"
#include "rsa_local.h"
/* Set any parameters associated with pkey */
static int rsa_param_encode(const EVP_PKEY *pkey,
ASN1_STRING **pstr, int *pstrtype)
{
const RSA *rsa = pkey->pkey.rsa;
*pstr = NULL;
/* If RSA it's just NULL type */
if (RSA_test_flags(rsa, RSA_FLAG_TYPE_MASK) != RSA_FLAG_TYPE_RSASSAPSS) {
*pstrtype = V_ASN1_NULL;
return 1;
}
/* If no PSS parameters we omit parameters entirely */
if (rsa->pss == NULL) {
*pstrtype = V_ASN1_UNDEF;
return 1;
}
/* Encode PSS parameters */
if (ASN1_item_pack(rsa->pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), pstr) == NULL)
return 0;
*pstrtype = V_ASN1_SEQUENCE;
return 1;
}
/* Decode any parameters and set them in RSA structure */
static int rsa_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
{
unsigned char *penc = NULL;
int penclen;
ASN1_STRING *str;
int strtype;
if (!rsa_param_encode(pkey, &str, &strtype))
return 0;
penclen = i2d_RSAPublicKey(pkey->pkey.rsa, &penc);
if (penclen <= 0) {
ASN1_STRING_free(str);
return 0;
}
if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
strtype, str, penc, penclen))
return 1;
OPENSSL_free(penc);
ASN1_STRING_free(str);
return 0;
}
static int rsa_pub_decode(EVP_PKEY *pkey, const X509_PUBKEY *pubkey)
{
const unsigned char *p;
int pklen;
X509_ALGOR *alg;
RSA *rsa = NULL;
if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &alg, pubkey))
return 0;
if ((rsa = d2i_RSAPublicKey(NULL, &p, pklen)) == NULL)
return 0;
if (!ossl_rsa_param_decode(rsa, alg)) {
RSA_free(rsa);
return 0;
}
RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
switch (pkey->ameth->pkey_id) {
case EVP_PKEY_RSA:
RSA_set_flags(rsa, RSA_FLAG_TYPE_RSA);
break;
case EVP_PKEY_RSA_PSS:
RSA_set_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS);
break;
default:
/* Leave the type bits zero */
break;
}
if (!EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa)) {
RSA_free(rsa);
return 0;
}
return 1;
}
static int rsa_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
{
/*
* Don't check the public/private key, this is mostly for smart
* cards.
*/
if (((RSA_flags(a->pkey.rsa) & RSA_METHOD_FLAG_NO_CHECK))
|| (RSA_flags(b->pkey.rsa) & RSA_METHOD_FLAG_NO_CHECK)) {
return 1;
}
if (BN_cmp(b->pkey.rsa->n, a->pkey.rsa->n) != 0
|| BN_cmp(b->pkey.rsa->e, a->pkey.rsa->e) != 0)
return 0;
return 1;
}
static int old_rsa_priv_decode(EVP_PKEY *pkey,
const unsigned char **pder, int derlen)
{
RSA *rsa;
if ((rsa = d2i_RSAPrivateKey(NULL, pder, derlen)) == NULL)
return 0;
EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa);
return 1;
}
static int old_rsa_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
{
return i2d_RSAPrivateKey(pkey->pkey.rsa, pder);
}
static int rsa_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
{
unsigned char *rk = NULL;
int rklen;
ASN1_STRING *str;
int strtype;
if (!rsa_param_encode(pkey, &str, &strtype))
return 0;
rklen = i2d_RSAPrivateKey(pkey->pkey.rsa, &rk);
if (rklen <= 0) {
ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE);
ASN1_STRING_free(str);
return 0;
}
if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
strtype, str, rk, rklen)) {
ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE);
ASN1_STRING_free(str);
OPENSSL_clear_free(rk, rklen);
return 0;
}
return 1;
}
static int rsa_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
{
int ret = 0;
RSA *rsa = ossl_rsa_key_from_pkcs8(p8, NULL, NULL);
if (rsa != NULL) {
ret = 1;
EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa);
}
return ret;
}
static int int_rsa_size(const EVP_PKEY *pkey)
{
return RSA_size(pkey->pkey.rsa);
}
static int rsa_bits(const EVP_PKEY *pkey)
{
return BN_num_bits(pkey->pkey.rsa->n);
}
static int rsa_security_bits(const EVP_PKEY *pkey)
{
return RSA_security_bits(pkey->pkey.rsa);
}
static void int_rsa_free(EVP_PKEY *pkey)
{
RSA_free(pkey->pkey.rsa);
}
static int rsa_pss_param_print(BIO *bp, int pss_key, RSA_PSS_PARAMS *pss,
int indent)
{
int rv = 0;
X509_ALGOR *maskHash = NULL;
if (!BIO_indent(bp, indent, 128))
goto err;
if (pss_key) {
if (pss == NULL) {
if (BIO_puts(bp, "No PSS parameter restrictions\n") <= 0)
return 0;
return 1;
} else {
if (BIO_puts(bp, "PSS parameter restrictions:") <= 0)
return 0;
}
} else if (pss == NULL) {
if (BIO_puts(bp,"(INVALID PSS PARAMETERS)\n") <= 0)
return 0;
return 1;
}
if (BIO_puts(bp, "\n") <= 0)
goto err;
if (pss_key)
indent += 2;
if (!BIO_indent(bp, indent, 128))
goto err;
if (BIO_puts(bp, "Hash Algorithm: ") <= 0)
goto err;
if (pss->hashAlgorithm) {
if (i2a_ASN1_OBJECT(bp, pss->hashAlgorithm->algorithm) <= 0)
goto err;
} else if (BIO_puts(bp, "sha1 (default)") <= 0) {
goto err;
}
if (BIO_puts(bp, "\n") <= 0)
goto err;
if (!BIO_indent(bp, indent, 128))
goto err;
if (BIO_puts(bp, "Mask Algorithm: ") <= 0)
goto err;
if (pss->maskGenAlgorithm) {
if (i2a_ASN1_OBJECT(bp, pss->maskGenAlgorithm->algorithm) <= 0)
goto err;
if (BIO_puts(bp, " with ") <= 0)
goto err;
maskHash = ossl_x509_algor_mgf1_decode(pss->maskGenAlgorithm);
if (maskHash != NULL) {
if (i2a_ASN1_OBJECT(bp, maskHash->algorithm) <= 0)
goto err;
} else if (BIO_puts(bp, "INVALID") <= 0) {
goto err;
}
} else if (BIO_puts(bp, "mgf1 with sha1 (default)") <= 0) {
goto err;
}
BIO_puts(bp, "\n");
if (!BIO_indent(bp, indent, 128))
goto err;
if (BIO_printf(bp, "%s Salt Length: 0x", pss_key ? "Minimum" : "") <= 0)
goto err;
if (pss->saltLength) {
if (i2a_ASN1_INTEGER(bp, pss->saltLength) <= 0)
goto err;
} else if (BIO_puts(bp, "14 (default)") <= 0) {
goto err;
}
BIO_puts(bp, "\n");
if (!BIO_indent(bp, indent, 128))
goto err;
if (BIO_puts(bp, "Trailer Field: 0x") <= 0)
goto err;
if (pss->trailerField) {
if (i2a_ASN1_INTEGER(bp, pss->trailerField) <= 0)
goto err;
} else if (BIO_puts(bp, "01 (default)") <= 0) {
goto err;
}
BIO_puts(bp, "\n");
rv = 1;
err:
X509_ALGOR_free(maskHash);
return rv;
}
static int pkey_rsa_print(BIO *bp, const EVP_PKEY *pkey, int off, int priv)
{
const RSA *x = pkey->pkey.rsa;
char *str;
const char *s;
int ret = 0, mod_len = 0, ex_primes;
if (x->n != NULL)
mod_len = BN_num_bits(x->n);
ex_primes = sk_RSA_PRIME_INFO_num(x->prime_infos);
if (!BIO_indent(bp, off, 128))
goto err;
if (BIO_printf(bp, "%s ", pkey_is_pss(pkey) ? "RSA-PSS" : "RSA") <= 0)
goto err;
if (priv && x->d) {
if (BIO_printf(bp, "Private-Key: (%d bit, %d primes)\n",
mod_len, ex_primes <= 0 ? 2 : ex_primes + 2) <= 0)
goto err;
str = "modulus:";
s = "publicExponent:";
} else {
if (BIO_printf(bp, "Public-Key: (%d bit)\n", mod_len) <= 0)
goto err;
str = "Modulus:";
s = "Exponent:";
}
if (!ASN1_bn_print(bp, str, x->n, NULL, off))
goto err;
if (!ASN1_bn_print(bp, s, x->e, NULL, off))
goto err;
if (priv) {
int i;
if (!ASN1_bn_print(bp, "privateExponent:", x->d, NULL, off))
goto err;
if (!ASN1_bn_print(bp, "prime1:", x->p, NULL, off))
goto err;
if (!ASN1_bn_print(bp, "prime2:", x->q, NULL, off))
goto err;
if (!ASN1_bn_print(bp, "exponent1:", x->dmp1, NULL, off))
goto err;
if (!ASN1_bn_print(bp, "exponent2:", x->dmq1, NULL, off))
goto err;
if (!ASN1_bn_print(bp, "coefficient:", x->iqmp, NULL, off))
goto err;
for (i = 0; i < sk_RSA_PRIME_INFO_num(x->prime_infos); i++) {
/* print multi-prime info */
BIGNUM *bn = NULL;
RSA_PRIME_INFO *pinfo;
int j;
pinfo = sk_RSA_PRIME_INFO_value(x->prime_infos, i);
for (j = 0; j < 3; j++) {
if (!BIO_indent(bp, off, 128))
goto err;
switch (j) {
case 0:
if (BIO_printf(bp, "prime%d:", i + 3) <= 0)
goto err;
bn = pinfo->r;
break;
case 1:
if (BIO_printf(bp, "exponent%d:", i + 3) <= 0)
goto err;
bn = pinfo->d;
break;
case 2:
if (BIO_printf(bp, "coefficient%d:", i + 3) <= 0)
goto err;
bn = pinfo->t;
break;
default:
break;
}
if (!ASN1_bn_print(bp, "", bn, NULL, off))
goto err;
}
}
}
if (pkey_is_pss(pkey) && !rsa_pss_param_print(bp, 1, x->pss, off))
goto err;
ret = 1;
err:
return ret;
}
static int rsa_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx)
{
return pkey_rsa_print(bp, pkey, indent, 0);
}
static int rsa_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx)
{
return pkey_rsa_print(bp, pkey, indent, 1);
}
static int rsa_sig_print(BIO *bp, const X509_ALGOR *sigalg,
const ASN1_STRING *sig, int indent, ASN1_PCTX *pctx)
{
if (OBJ_obj2nid(sigalg->algorithm) == EVP_PKEY_RSA_PSS) {
int rv;
RSA_PSS_PARAMS *pss = ossl_rsa_pss_decode(sigalg);
rv = rsa_pss_param_print(bp, 0, pss, indent);
RSA_PSS_PARAMS_free(pss);
if (!rv)
return 0;
} else if (BIO_puts(bp, "\n") <= 0) {
return 0;
}
if (sig)
return X509_signature_dump(bp, sig, indent);
return 1;
}
static int rsa_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
{
const EVP_MD *md;
const EVP_MD *mgf1md;
int min_saltlen;
switch (op) {
case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
if (pkey->pkey.rsa->pss != NULL) {
if (!ossl_rsa_pss_get_param(pkey->pkey.rsa->pss, &md, &mgf1md,
&min_saltlen)) {
ERR_raise(ERR_LIB_RSA, ERR_R_INTERNAL_ERROR);
return 0;
}
*(int *)arg2 = EVP_MD_get_type(md);
/* Return of 2 indicates this MD is mandatory */
return 2;
}
*(int *)arg2 = NID_sha256;
return 1;
default:
return -2;
}
}
/*
* Convert EVP_PKEY_CTX in PSS mode into corresponding algorithm parameter,
* suitable for setting an AlgorithmIdentifier.
*/
static RSA_PSS_PARAMS *rsa_ctx_to_pss(EVP_PKEY_CTX *pkctx)
{
const EVP_MD *sigmd, *mgf1md;
EVP_PKEY *pk = EVP_PKEY_CTX_get0_pkey(pkctx);
int saltlen;
int saltlenMax = -1;
if (EVP_PKEY_CTX_get_signature_md(pkctx, &sigmd) <= 0)
return NULL;
if (EVP_PKEY_CTX_get_rsa_mgf1_md(pkctx, &mgf1md) <= 0)
return NULL;
if (EVP_PKEY_CTX_get_rsa_pss_saltlen(pkctx, &saltlen) <= 0)
return NULL;
if (saltlen == RSA_PSS_SALTLEN_DIGEST) {
saltlen = EVP_MD_get_size(sigmd);
} else if (saltlen == RSA_PSS_SALTLEN_AUTO_DIGEST_MAX) {
/* FIPS 186-4 section 5 "The RSA Digital Signature Algorithm",
* subsection 5.5 "PKCS #1" says: "For RSASSA-PSS […] the length (in
* bytes) of the salt (sLen) shall satisfy 0 <= sLen <= hLen, where
* hLen is the length of the hash function output block (in bytes)."
*
* Provide a way to use at most the digest length, so that the default
* does not violate FIPS 186-4. */
saltlen = RSA_PSS_SALTLEN_MAX;
saltlenMax = EVP_MD_get_size(sigmd);
}
if (saltlen == RSA_PSS_SALTLEN_MAX || saltlen == RSA_PSS_SALTLEN_AUTO) {
saltlen = EVP_PKEY_get_size(pk) - EVP_MD_get_size(sigmd) - 2;
if ((EVP_PKEY_get_bits(pk) & 0x7) == 1)
saltlen--;
if (saltlen < 0)
return NULL;
if (saltlenMax >= 0 && saltlen > saltlenMax)
saltlen = saltlenMax;
}
return ossl_rsa_pss_params_create(sigmd, mgf1md, saltlen);
}
RSA_PSS_PARAMS *ossl_rsa_pss_params_create(const EVP_MD *sigmd,
const EVP_MD *mgf1md, int saltlen)
{
RSA_PSS_PARAMS *pss = RSA_PSS_PARAMS_new();
if (pss == NULL)
goto err;
if (saltlen != 20) {
pss->saltLength = ASN1_INTEGER_new();
if (pss->saltLength == NULL)
goto err;
if (!ASN1_INTEGER_set(pss->saltLength, saltlen))
goto err;
}
if (!ossl_x509_algor_new_from_md(&pss->hashAlgorithm, sigmd))
goto err;
if (mgf1md == NULL)
mgf1md = sigmd;
if (!ossl_x509_algor_md_to_mgf1(&pss->maskGenAlgorithm, mgf1md))
goto err;
if (!ossl_x509_algor_new_from_md(&pss->maskHash, mgf1md))
goto err;
return pss;
err:
RSA_PSS_PARAMS_free(pss);
return NULL;
}
ASN1_STRING *ossl_rsa_ctx_to_pss_string(EVP_PKEY_CTX *pkctx)
{
RSA_PSS_PARAMS *pss = rsa_ctx_to_pss(pkctx);
ASN1_STRING *os;
if (pss == NULL)
return NULL;
os = ASN1_item_pack(pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), NULL);
RSA_PSS_PARAMS_free(pss);
return os;
}
/*
* From PSS AlgorithmIdentifier set public key parameters. If pkey isn't NULL
* then the EVP_MD_CTX is setup and initialised. If it is NULL parameters are
* passed to pkctx instead.
*/
int ossl_rsa_pss_to_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pkctx,
const X509_ALGOR *sigalg, EVP_PKEY *pkey)
{
int rv = -1;
int saltlen;
const EVP_MD *mgf1md = NULL, *md = NULL;
RSA_PSS_PARAMS *pss;
/* Sanity check: make sure it is PSS */
if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS) {
ERR_raise(ERR_LIB_RSA, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
return -1;
}
/* Decode PSS parameters */
pss = ossl_rsa_pss_decode(sigalg);
if (!ossl_rsa_pss_get_param(pss, &md, &mgf1md, &saltlen)) {
ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_PSS_PARAMETERS);
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_get_type(md) != EVP_MD_get_type(checkmd)) {
ERR_raise(ERR_LIB_RSA, RSA_R_DIGEST_DOES_NOT_MATCH);
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);
return rv;
}
static int rsa_pss_verify_param(const EVP_MD **pmd, const EVP_MD **pmgf1md,
int *psaltlen, int *ptrailerField)
{
if (psaltlen != NULL && *psaltlen < 0) {
ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_SALT_LENGTH);
return 0;
}
/*
* low-level routines support only trailer field 0xbc (value 1) and
* PKCS#1 says we should reject any other value anyway.
*/
if (ptrailerField != NULL && *ptrailerField != 1) {
ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_TRAILER);
return 0;
}
return 1;
}
int ossl_rsa_pss_get_param(const RSA_PSS_PARAMS *pss, const EVP_MD **pmd,
const EVP_MD **pmgf1md, int *psaltlen)
{
/*
* Callers do not care about the trailer field, and yet, we must
* pass it from get_param to verify_param, since the latter checks
* its value.
*
* When callers start caring, it's a simple thing to add another
* argument to this function.
*/
int trailerField = 0;
return ossl_rsa_pss_get_param_unverified(pss, pmd, pmgf1md, psaltlen,
&trailerField)
&& rsa_pss_verify_param(pmd, pmgf1md, psaltlen, &trailerField);
}
/*
* Customised RSA item verification routine. This is called when a signature
* is encountered requiring special handling. We currently only handle PSS.
*/
static int rsa_item_verify(EVP_MD_CTX *ctx, const ASN1_ITEM *it,
const void *asn, const X509_ALGOR *sigalg,
const ASN1_BIT_STRING *sig, EVP_PKEY *pkey)
{
/* Sanity check: make sure it is PSS */
if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS) {
ERR_raise(ERR_LIB_RSA, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
return -1;
}
if (ossl_rsa_pss_to_ctx(ctx, NULL, sigalg, pkey) > 0) {
/* Carry on */
return 2;
}
return -1;
}
static int rsa_item_sign(EVP_MD_CTX *ctx, const ASN1_ITEM *it, const void *asn,
X509_ALGOR *alg1, X509_ALGOR *alg2,
ASN1_BIT_STRING *sig)
{
int pad_mode;
EVP_PKEY_CTX *pkctx = EVP_MD_CTX_get_pkey_ctx(ctx);
if (EVP_PKEY_CTX_get_rsa_padding(pkctx, &pad_mode) <= 0)
return 0;
if (pad_mode == RSA_PKCS1_PADDING)
return 2;
if (pad_mode == RSA_PKCS1_PSS_PADDING) {
unsigned char aid[128];
size_t aid_len = 0;
OSSL_PARAM params[2];
if (evp_pkey_ctx_is_legacy(pkctx)) {
/* No provider -> we cannot query it for algorithm ID. */
ASN1_STRING *os1 = NULL;
os1 = ossl_rsa_ctx_to_pss_string(pkctx);
if (os1 == NULL)
return 0;
/* Duplicate parameters if we have to */
if (alg2 != NULL) {
ASN1_STRING *os2 = ASN1_STRING_dup(os1);
if (os2 == NULL) {
ASN1_STRING_free(os1);
return 0;
}
if (!X509_ALGOR_set0(alg2, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
V_ASN1_SEQUENCE, os2)) {
ASN1_STRING_free(os1);
ASN1_STRING_free(os2);
return 0;
}
}
if (!X509_ALGOR_set0(alg1, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
V_ASN1_SEQUENCE, os1)) {
ASN1_STRING_free(os1);
return 0;
}
return 3;
}
params[0] = OSSL_PARAM_construct_octet_string(
OSSL_SIGNATURE_PARAM_ALGORITHM_ID, aid, sizeof(aid));
params[1] = OSSL_PARAM_construct_end();
if (EVP_PKEY_CTX_get_params(pkctx, params) <= 0)
return 0;
if ((aid_len = params[0].return_size) == 0)
return 0;
if (alg1 != NULL) {
const unsigned char *pp = aid;
if (d2i_X509_ALGOR(&alg1, &pp, aid_len) == NULL)
return 0;
}
if (alg2 != NULL) {
const unsigned char *pp = aid;
if (d2i_X509_ALGOR(&alg2, &pp, aid_len) == NULL)
return 0;
}
return 3;
}
return 2;
}
static int rsa_sig_info_set(X509_SIG_INFO *siginf, const X509_ALGOR *sigalg,
const ASN1_STRING *sig)
{
int rv = 0;
int mdnid, saltlen;
uint32_t flags;
const EVP_MD *mgf1md = NULL, *md = NULL;
RSA_PSS_PARAMS *pss;
int secbits;
/* Sanity check: make sure it is PSS */
if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS)
return 0;
/* Decode PSS parameters */
pss = ossl_rsa_pss_decode(sigalg);
if (!ossl_rsa_pss_get_param(pss, &md, &mgf1md, &saltlen))
goto err;
mdnid = EVP_MD_get_type(md);
/*
* For TLS need SHA256, SHA384 or SHA512, digest and MGF1 digest must
* match and salt length must equal digest size
*/
if ((mdnid == NID_sha256 || mdnid == NID_sha384 || mdnid == NID_sha512)
&& mdnid == EVP_MD_get_type(mgf1md)
&& saltlen == EVP_MD_get_size(md))
flags = X509_SIG_INFO_TLS;
else
flags = 0;
/* Note: security bits half number of digest bits */
secbits = EVP_MD_get_size(md) * 4;
/*
* SHA1 and MD5 are known to be broken. Reduce security bits so that
* they're no longer accepted at security level 1. The real values don't
* really matter as long as they're lower than 80, which is our security
* level 1.
* https://eprint.iacr.org/2020/014 puts a chosen-prefix attack for SHA1 at
* 2^63.4
* https://documents.epfl.ch/users/l/le/lenstra/public/papers/lat.pdf
* puts a chosen-prefix attack for MD5 at 2^39.
*/
if (mdnid == NID_sha1)
secbits = 64;
else if (mdnid == NID_md5_sha1)
secbits = 68;
else if (mdnid == NID_md5)
secbits = 39;
X509_SIG_INFO_set(siginf, mdnid, EVP_PKEY_RSA_PSS, secbits,
flags);
rv = 1;
err:
RSA_PSS_PARAMS_free(pss);
return rv;
}
static int rsa_pkey_check(const EVP_PKEY *pkey)
{
return RSA_check_key_ex(pkey->pkey.rsa, NULL);
}
static size_t rsa_pkey_dirty_cnt(const EVP_PKEY *pkey)
{
return pkey->pkey.rsa->dirty_cnt;
}
/*
* There is no need to do RSA_test_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS)
* checks in this method since the caller tests EVP_KEYMGMT_is_a() first.
*/
static int rsa_int_export_to(const EVP_PKEY *from, int rsa_type,
void *to_keydata,
OSSL_FUNC_keymgmt_import_fn *importer,
OSSL_LIB_CTX *libctx, const char *propq)
{
RSA *rsa = from->pkey.rsa;
OSSL_PARAM_BLD *tmpl = OSSL_PARAM_BLD_new();
OSSL_PARAM *params = NULL;
int selection = 0;
int rv = 0;
if (tmpl == NULL)
return 0;
/* Public parameters must always be present */
if (RSA_get0_n(rsa) == NULL || RSA_get0_e(rsa) == NULL)
goto err;
if (!ossl_rsa_todata(rsa, tmpl, NULL, 1))
goto err;
selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
if (RSA_get0_d(rsa) != NULL)
selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
if (rsa->pss != NULL) {
const EVP_MD *md = NULL, *mgf1md = NULL;
int md_nid, mgf1md_nid, saltlen, trailerfield;
RSA_PSS_PARAMS_30 pss_params;
if (!ossl_rsa_pss_get_param_unverified(rsa->pss, &md, &mgf1md,
&saltlen, &trailerfield))
goto err;
md_nid = EVP_MD_get_type(md);
mgf1md_nid = EVP_MD_get_type(mgf1md);
if (!ossl_rsa_pss_params_30_set_defaults(&pss_params)
|| !ossl_rsa_pss_params_30_set_hashalg(&pss_params, md_nid)
|| !ossl_rsa_pss_params_30_set_maskgenhashalg(&pss_params,
mgf1md_nid)
|| !ossl_rsa_pss_params_30_set_saltlen(&pss_params, saltlen)
|| !ossl_rsa_pss_params_30_todata(&pss_params, tmpl, NULL))
goto err;
selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
}
if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
goto err;
/* We export, the provider imports */
rv = importer(to_keydata, selection, params);
err:
OSSL_PARAM_free(params);
OSSL_PARAM_BLD_free(tmpl);
return rv;
}
static int rsa_int_import_from(const OSSL_PARAM params[], void *vpctx,
int rsa_type)
{
EVP_PKEY_CTX *pctx = vpctx;
EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
RSA *rsa = ossl_rsa_new_with_ctx(pctx->libctx);
RSA_PSS_PARAMS_30 rsa_pss_params = { 0, };
int pss_defaults_set = 0;
int ok = 0;
if (rsa == NULL) {
ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
return 0;
}
RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
RSA_set_flags(rsa, rsa_type);
if (!ossl_rsa_pss_params_30_fromdata(&rsa_pss_params, &pss_defaults_set,
params, pctx->libctx))
goto err;
switch (rsa_type) {
case RSA_FLAG_TYPE_RSA:
/*
* Were PSS parameters filled in?
* In that case, something's wrong
*/
if (!ossl_rsa_pss_params_30_is_unrestricted(&rsa_pss_params))
goto err;
break;
case RSA_FLAG_TYPE_RSASSAPSS:
/*
* Were PSS parameters filled in? In that case, create the old
* RSA_PSS_PARAMS structure. Otherwise, this is an unrestricted key.
*/
if (!ossl_rsa_pss_params_30_is_unrestricted(&rsa_pss_params)) {
/* Create the older RSA_PSS_PARAMS from RSA_PSS_PARAMS_30 data */
int mdnid = ossl_rsa_pss_params_30_hashalg(&rsa_pss_params);
int mgf1mdnid = ossl_rsa_pss_params_30_maskgenhashalg(&rsa_pss_params);
int saltlen = ossl_rsa_pss_params_30_saltlen(&rsa_pss_params);
const EVP_MD *md = EVP_get_digestbynid(mdnid);
const EVP_MD *mgf1md = EVP_get_digestbynid(mgf1mdnid);
if ((rsa->pss = ossl_rsa_pss_params_create(md, mgf1md,
saltlen)) == NULL)
goto err;
}
break;
default:
/* RSA key sub-types we don't know how to handle yet */
goto err;
}
if (!ossl_rsa_fromdata(rsa, params, 1))
goto err;
switch (rsa_type) {
case RSA_FLAG_TYPE_RSA:
ok = EVP_PKEY_assign_RSA(pkey, rsa);
break;
case RSA_FLAG_TYPE_RSASSAPSS:
ok = EVP_PKEY_assign(pkey, EVP_PKEY_RSA_PSS, rsa);
break;
}
err:
if (!ok)
RSA_free(rsa);
return ok;
}
static int rsa_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
OSSL_FUNC_keymgmt_import_fn *importer,
OSSL_LIB_CTX *libctx, const char *propq)
{
return rsa_int_export_to(from, RSA_FLAG_TYPE_RSA, to_keydata,
importer, libctx, propq);
}
static int rsa_pss_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
OSSL_FUNC_keymgmt_import_fn *importer,
OSSL_LIB_CTX *libctx, const char *propq)
{
return rsa_int_export_to(from, RSA_FLAG_TYPE_RSASSAPSS, to_keydata,
importer, libctx, propq);
}
static int rsa_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
{
return rsa_int_import_from(params, vpctx, RSA_FLAG_TYPE_RSA);
}
static int rsa_pss_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
{
return rsa_int_import_from(params, vpctx, RSA_FLAG_TYPE_RSASSAPSS);
}
static int rsa_pkey_copy(EVP_PKEY *to, EVP_PKEY *from)
{
RSA *rsa = from->pkey.rsa;
RSA *dupkey = NULL;
int ret;
if (rsa != NULL) {
dupkey = ossl_rsa_dup(rsa, OSSL_KEYMGMT_SELECT_ALL);
if (dupkey == NULL)
return 0;
}
ret = EVP_PKEY_assign(to, from->type, dupkey);
if (!ret)
RSA_free(dupkey);
return ret;
}
const EVP_PKEY_ASN1_METHOD ossl_rsa_asn1_meths[2] = {
{
EVP_PKEY_RSA,
EVP_PKEY_RSA,
ASN1_PKEY_SIGPARAM_NULL,
"RSA",
"OpenSSL RSA method",
rsa_pub_decode,
rsa_pub_encode,
rsa_pub_cmp,
rsa_pub_print,
rsa_priv_decode,
rsa_priv_encode,
rsa_priv_print,
int_rsa_size,
rsa_bits,
rsa_security_bits,
0, 0, 0, 0, 0, 0,
rsa_sig_print,
int_rsa_free,
rsa_pkey_ctrl,
old_rsa_priv_decode,
old_rsa_priv_encode,
rsa_item_verify,
rsa_item_sign,
rsa_sig_info_set,
rsa_pkey_check,
0, 0,
0, 0, 0, 0,
rsa_pkey_dirty_cnt,
rsa_pkey_export_to,
rsa_pkey_import_from,
rsa_pkey_copy
},
{
EVP_PKEY_RSA2,
EVP_PKEY_RSA,
ASN1_PKEY_ALIAS}
};
const EVP_PKEY_ASN1_METHOD ossl_rsa_pss_asn1_meth = {
EVP_PKEY_RSA_PSS,
EVP_PKEY_RSA_PSS,
ASN1_PKEY_SIGPARAM_NULL,
"RSA-PSS",
"OpenSSL RSA-PSS method",
rsa_pub_decode,
rsa_pub_encode,
rsa_pub_cmp,
rsa_pub_print,
rsa_priv_decode,
rsa_priv_encode,
rsa_priv_print,
int_rsa_size,
rsa_bits,
rsa_security_bits,
0, 0, 0, 0, 0, 0,
rsa_sig_print,
int_rsa_free,
rsa_pkey_ctrl,
0, 0,
rsa_item_verify,
rsa_item_sign,
rsa_sig_info_set,
rsa_pkey_check,
0, 0,
0, 0, 0, 0,
rsa_pkey_dirty_cnt,
rsa_pss_pkey_export_to,
rsa_pss_pkey_import_from,
rsa_pkey_copy
};
