rsa_enc.c
/*
* Copyright 2019-2023 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 <openssl/crypto.h>
#include <openssl/evp.h>
#include <openssl/core_dispatch.h>
#include <openssl/core_names.h>
#include <openssl/rsa.h>
#include <openssl/params.h>
#include <openssl/err.h>
#include <openssl/proverr.h>
/* Just for SSL_MAX_MASTER_KEY_LENGTH */
#include <openssl/prov_ssl.h>
#include "internal/constant_time.h"
#include "internal/sizes.h"
#include "crypto/rsa.h"
#include "prov/provider_ctx.h"
#include "prov/implementations.h"
#include "prov/providercommon.h"
#include "prov/securitycheck.h"
#include <stdlib.h>
static OSSL_FUNC_asym_cipher_newctx_fn rsa_newctx;
static OSSL_FUNC_asym_cipher_encrypt_init_fn rsa_encrypt_init;
static OSSL_FUNC_asym_cipher_encrypt_fn rsa_encrypt;
static OSSL_FUNC_asym_cipher_decrypt_init_fn rsa_decrypt_init;
static OSSL_FUNC_asym_cipher_decrypt_fn rsa_decrypt;
static OSSL_FUNC_asym_cipher_freectx_fn rsa_freectx;
static OSSL_FUNC_asym_cipher_dupctx_fn rsa_dupctx;
static OSSL_FUNC_asym_cipher_get_ctx_params_fn rsa_get_ctx_params;
static OSSL_FUNC_asym_cipher_gettable_ctx_params_fn rsa_gettable_ctx_params;
static OSSL_FUNC_asym_cipher_set_ctx_params_fn rsa_set_ctx_params;
static OSSL_FUNC_asym_cipher_settable_ctx_params_fn rsa_settable_ctx_params;
static OSSL_ITEM padding_item[] = {
{ RSA_PKCS1_PADDING, OSSL_PKEY_RSA_PAD_MODE_PKCSV15 },
{ RSA_NO_PADDING, OSSL_PKEY_RSA_PAD_MODE_NONE },
{ RSA_PKCS1_OAEP_PADDING, OSSL_PKEY_RSA_PAD_MODE_OAEP }, /* Correct spelling first */
{ RSA_PKCS1_OAEP_PADDING, "oeap" },
{ RSA_X931_PADDING, OSSL_PKEY_RSA_PAD_MODE_X931 },
{ 0, NULL }
};
/*
* What's passed as an actual key is defined by the KEYMGMT interface.
* We happen to know that our KEYMGMT simply passes RSA structures, so
* we use that here too.
*/
typedef struct {
OSSL_LIB_CTX *libctx;
RSA *rsa;
int pad_mode;
int operation;
/* OAEP message digest */
EVP_MD *oaep_md;
/* message digest for MGF1 */
EVP_MD *mgf1_md;
/* OAEP label */
unsigned char *oaep_label;
size_t oaep_labellen;
/* TLS padding */
unsigned int client_version;
unsigned int alt_version;
/* PKCS#1 v1.5 decryption mode */
unsigned int implicit_rejection;
} PROV_RSA_CTX;
static void *rsa_newctx(void *provctx)
{
PROV_RSA_CTX *prsactx;
if (!ossl_prov_is_running())
return NULL;
prsactx = OPENSSL_zalloc(sizeof(PROV_RSA_CTX));
if (prsactx == NULL)
return NULL;
prsactx->libctx = PROV_LIBCTX_OF(provctx);
return prsactx;
}
static int rsa_init(void *vprsactx, void *vrsa, const OSSL_PARAM params[],
int operation)
{
PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
if (!ossl_prov_is_running() || prsactx == NULL || vrsa == NULL)
return 0;
if (!ossl_rsa_check_key(prsactx->libctx, vrsa, operation))
return 0;
if (!RSA_up_ref(vrsa))
return 0;
RSA_free(prsactx->rsa);
prsactx->rsa = vrsa;
prsactx->operation = operation;
prsactx->implicit_rejection = 1;
switch (RSA_test_flags(prsactx->rsa, RSA_FLAG_TYPE_MASK)) {
case RSA_FLAG_TYPE_RSA:
prsactx->pad_mode = RSA_PKCS1_PADDING;
break;
default:
/* This should not happen due to the check above */
ERR_raise(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR);
return 0;
}
return rsa_set_ctx_params(prsactx, params);
}
static int rsa_encrypt_init(void *vprsactx, void *vrsa,
const OSSL_PARAM params[])
{
return rsa_init(vprsactx, vrsa, params, EVP_PKEY_OP_ENCRYPT);
}
static int rsa_decrypt_init(void *vprsactx, void *vrsa,
const OSSL_PARAM params[])
{
return rsa_init(vprsactx, vrsa, params, EVP_PKEY_OP_DECRYPT);
}
static int rsa_encrypt(void *vprsactx, unsigned char *out, size_t *outlen,
size_t outsize, const unsigned char *in, size_t inlen)
{
PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
int ret;
if (!ossl_prov_is_running())
return 0;
if (out == NULL) {
size_t len = RSA_size(prsactx->rsa);
if (len == 0) {
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY);
return 0;
}
*outlen = len;
return 1;
}
if (prsactx->pad_mode == RSA_PKCS1_OAEP_PADDING) {
int rsasize = RSA_size(prsactx->rsa);
unsigned char *tbuf;
if ((tbuf = OPENSSL_malloc(rsasize)) == NULL)
return 0;
if (prsactx->oaep_md == NULL) {
prsactx->oaep_md = EVP_MD_fetch(prsactx->libctx, "SHA-1", NULL);
if (prsactx->oaep_md == NULL) {
OPENSSL_free(tbuf);
ERR_raise(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR);
return 0;
}
}
ret =
ossl_rsa_padding_add_PKCS1_OAEP_mgf1_ex(prsactx->libctx, tbuf,
rsasize, in, inlen,
prsactx->oaep_label,
prsactx->oaep_labellen,
prsactx->oaep_md,
prsactx->mgf1_md);
if (!ret) {
OPENSSL_free(tbuf);
return 0;
}
ret = RSA_public_encrypt(rsasize, tbuf, out, prsactx->rsa,
RSA_NO_PADDING);
OPENSSL_free(tbuf);
} else {
ret = RSA_public_encrypt(inlen, in, out, prsactx->rsa,
prsactx->pad_mode);
}
/* A ret value of 0 is not an error */
if (ret < 0)
return ret;
*outlen = ret;
return 1;
}
static int rsa_decrypt(void *vprsactx, unsigned char *out, size_t *outlen,
size_t outsize, const unsigned char *in, size_t inlen)
{
PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
int ret;
int pad_mode;
size_t len = RSA_size(prsactx->rsa);
if (!ossl_prov_is_running())
return 0;
if (prsactx->pad_mode == RSA_PKCS1_WITH_TLS_PADDING) {
if (out == NULL) {
*outlen = SSL_MAX_MASTER_KEY_LENGTH;
return 1;
}
if (outsize < SSL_MAX_MASTER_KEY_LENGTH) {
ERR_raise(ERR_LIB_PROV, PROV_R_BAD_LENGTH);
return 0;
}
} else {
if (out == NULL) {
if (len == 0) {
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY);
return 0;
}
*outlen = len;
return 1;
}
if (outsize < len) {
ERR_raise(ERR_LIB_PROV, PROV_R_BAD_LENGTH);
return 0;
}
}
if (prsactx->pad_mode == RSA_PKCS1_OAEP_PADDING
|| prsactx->pad_mode == RSA_PKCS1_WITH_TLS_PADDING) {
unsigned char *tbuf;
if ((tbuf = OPENSSL_malloc(len)) == NULL)
return 0;
ret = RSA_private_decrypt(inlen, in, tbuf, prsactx->rsa,
RSA_NO_PADDING);
/*
* With no padding then, on success ret should be len, otherwise an
* error occurred (non-constant time)
*/
if (ret != (int)len) {
OPENSSL_free(tbuf);
ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_DECRYPT);
return 0;
}
if (prsactx->pad_mode == RSA_PKCS1_OAEP_PADDING) {
if (prsactx->oaep_md == NULL) {
prsactx->oaep_md = EVP_MD_fetch(prsactx->libctx, "SHA-1", NULL);
if (prsactx->oaep_md == NULL) {
OPENSSL_free(tbuf);
ERR_raise(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR);
return 0;
}
}
ret = RSA_padding_check_PKCS1_OAEP_mgf1(out, outsize, tbuf,
len, len,
prsactx->oaep_label,
prsactx->oaep_labellen,
prsactx->oaep_md,
prsactx->mgf1_md);
} else {
/* RSA_PKCS1_WITH_TLS_PADDING */
if (prsactx->client_version <= 0) {
ERR_raise(ERR_LIB_PROV, PROV_R_BAD_TLS_CLIENT_VERSION);
OPENSSL_free(tbuf);
return 0;
}
ret = ossl_rsa_padding_check_PKCS1_type_2_TLS(
prsactx->libctx, out, outsize, tbuf, len,
prsactx->client_version, prsactx->alt_version);
}
OPENSSL_free(tbuf);
} else {
if ((prsactx->implicit_rejection == 0) &&
(prsactx->pad_mode == RSA_PKCS1_PADDING))
pad_mode = RSA_PKCS1_NO_IMPLICIT_REJECT_PADDING;
else
pad_mode = prsactx->pad_mode;
ret = RSA_private_decrypt(inlen, in, out, prsactx->rsa, pad_mode);
}
*outlen = constant_time_select_s(constant_time_msb_s(ret), *outlen, ret);
ret = constant_time_select_int(constant_time_msb(ret), 0, 1);
return ret;
}
static void rsa_freectx(void *vprsactx)
{
PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
RSA_free(prsactx->rsa);
EVP_MD_free(prsactx->oaep_md);
EVP_MD_free(prsactx->mgf1_md);
OPENSSL_free(prsactx->oaep_label);
OPENSSL_free(prsactx);
}
static void *rsa_dupctx(void *vprsactx)
{
PROV_RSA_CTX *srcctx = (PROV_RSA_CTX *)vprsactx;
PROV_RSA_CTX *dstctx;
if (!ossl_prov_is_running())
return NULL;
dstctx = OPENSSL_zalloc(sizeof(*srcctx));
if (dstctx == NULL)
return NULL;
*dstctx = *srcctx;
if (dstctx->rsa != NULL && !RSA_up_ref(dstctx->rsa)) {
OPENSSL_free(dstctx);
return NULL;
}
if (dstctx->oaep_md != NULL && !EVP_MD_up_ref(dstctx->oaep_md)) {
RSA_free(dstctx->rsa);
OPENSSL_free(dstctx);
return NULL;
}
if (dstctx->mgf1_md != NULL && !EVP_MD_up_ref(dstctx->mgf1_md)) {
RSA_free(dstctx->rsa);
EVP_MD_free(dstctx->oaep_md);
OPENSSL_free(dstctx);
return NULL;
}
return dstctx;
}
static int rsa_get_ctx_params(void *vprsactx, OSSL_PARAM *params)
{
PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
OSSL_PARAM *p;
if (prsactx == NULL)
return 0;
p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_PAD_MODE);
if (p != NULL)
switch (p->data_type) {
case OSSL_PARAM_INTEGER: /* Support for legacy pad mode number */
if (!OSSL_PARAM_set_int(p, prsactx->pad_mode))
return 0;
break;
case OSSL_PARAM_UTF8_STRING:
{
int i;
const char *word = NULL;
for (i = 0; padding_item[i].id != 0; i++) {
if (prsactx->pad_mode == (int)padding_item[i].id) {
word = padding_item[i].ptr;
break;
}
}
if (word != NULL) {
if (!OSSL_PARAM_set_utf8_string(p, word))
return 0;
} else {
ERR_raise(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR);
}
}
break;
default:
return 0;
}
p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST);
if (p != NULL && !OSSL_PARAM_set_utf8_string(p, prsactx->oaep_md == NULL
? ""
: EVP_MD_get0_name(prsactx->oaep_md)))
return 0;
p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST);
if (p != NULL) {
EVP_MD *mgf1_md = prsactx->mgf1_md == NULL ? prsactx->oaep_md
: prsactx->mgf1_md;
if (!OSSL_PARAM_set_utf8_string(p, mgf1_md == NULL
? ""
: EVP_MD_get0_name(mgf1_md)))
return 0;
}
p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL);
if (p != NULL &&
!OSSL_PARAM_set_octet_ptr(p, prsactx->oaep_label,
prsactx->oaep_labellen))
return 0;
p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION);
if (p != NULL && !OSSL_PARAM_set_uint(p, prsactx->client_version))
return 0;
p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION);
if (p != NULL && !OSSL_PARAM_set_uint(p, prsactx->alt_version))
return 0;
p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_IMPLICIT_REJECTION);
if (p != NULL && !OSSL_PARAM_set_uint(p, prsactx->implicit_rejection))
return 0;
return 1;
}
static const OSSL_PARAM known_gettable_ctx_params[] = {
OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST, NULL, 0),
OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_PAD_MODE, NULL, 0),
OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST, NULL, 0),
OSSL_PARAM_DEFN(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL, OSSL_PARAM_OCTET_PTR,
NULL, 0),
OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION, NULL),
OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION, NULL),
OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_IMPLICIT_REJECTION, NULL),
OSSL_PARAM_END
};
static const OSSL_PARAM *rsa_gettable_ctx_params(ossl_unused void *vprsactx,
ossl_unused void *provctx)
{
return known_gettable_ctx_params;
}
static int rsa_set_ctx_params(void *vprsactx, const OSSL_PARAM params[])
{
PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
const OSSL_PARAM *p;
char mdname[OSSL_MAX_NAME_SIZE];
char mdprops[OSSL_MAX_PROPQUERY_SIZE] = { '\0' };
char *str = NULL;
if (prsactx == NULL)
return 0;
if (params == NULL)
return 1;
p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST);
if (p != NULL) {
str = mdname;
if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdname)))
return 0;
p = OSSL_PARAM_locate_const(params,
OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST_PROPS);
if (p != NULL) {
str = mdprops;
if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdprops)))
return 0;
}
EVP_MD_free(prsactx->oaep_md);
prsactx->oaep_md = EVP_MD_fetch(prsactx->libctx, mdname, mdprops);
if (prsactx->oaep_md == NULL)
return 0;
}
p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_PAD_MODE);
if (p != NULL) {
int pad_mode = 0;
switch (p->data_type) {
case OSSL_PARAM_INTEGER: /* Support for legacy pad mode number */
if (!OSSL_PARAM_get_int(p, &pad_mode))
return 0;
break;
case OSSL_PARAM_UTF8_STRING:
{
int i;
if (p->data == NULL)
return 0;
for (i = 0; padding_item[i].id != 0; i++) {
if (strcmp(p->data, padding_item[i].ptr) == 0) {
pad_mode = padding_item[i].id;
break;
}
}
}
break;
default:
return 0;
}
/*
* PSS padding is for signatures only so is not compatible with
* asymmetric cipher use.
*/
if (pad_mode == RSA_PKCS1_PSS_PADDING)
return 0;
if (pad_mode == RSA_PKCS1_OAEP_PADDING && prsactx->oaep_md == NULL) {
prsactx->oaep_md = EVP_MD_fetch(prsactx->libctx, "SHA1", mdprops);
if (prsactx->oaep_md == NULL)
return 0;
}
prsactx->pad_mode = pad_mode;
}
p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST);
if (p != NULL) {
str = mdname;
if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdname)))
return 0;
p = OSSL_PARAM_locate_const(params,
OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST_PROPS);
if (p != NULL) {
str = mdprops;
if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdprops)))
return 0;
} else {
str = NULL;
}
EVP_MD_free(prsactx->mgf1_md);
prsactx->mgf1_md = EVP_MD_fetch(prsactx->libctx, mdname, str);
if (prsactx->mgf1_md == NULL)
return 0;
}
p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL);
if (p != NULL) {
void *tmp_label = NULL;
size_t tmp_labellen;
if (!OSSL_PARAM_get_octet_string(p, &tmp_label, 0, &tmp_labellen))
return 0;
OPENSSL_free(prsactx->oaep_label);
prsactx->oaep_label = (unsigned char *)tmp_label;
prsactx->oaep_labellen = tmp_labellen;
}
p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION);
if (p != NULL) {
unsigned int client_version;
if (!OSSL_PARAM_get_uint(p, &client_version))
return 0;
prsactx->client_version = client_version;
}
p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION);
if (p != NULL) {
unsigned int alt_version;
if (!OSSL_PARAM_get_uint(p, &alt_version))
return 0;
prsactx->alt_version = alt_version;
}
p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_IMPLICIT_REJECTION);
if (p != NULL) {
unsigned int implicit_rejection;
if (!OSSL_PARAM_get_uint(p, &implicit_rejection))
return 0;
prsactx->implicit_rejection = implicit_rejection;
}
return 1;
}
static const OSSL_PARAM known_settable_ctx_params[] = {
OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST, NULL, 0),
OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_PAD_MODE, NULL, 0),
OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST, NULL, 0),
OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST_PROPS, NULL, 0),
OSSL_PARAM_octet_string(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL, NULL, 0),
OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION, NULL),
OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION, NULL),
OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_IMPLICIT_REJECTION, NULL),
OSSL_PARAM_END
};
static const OSSL_PARAM *rsa_settable_ctx_params(ossl_unused void *vprsactx,
ossl_unused void *provctx)
{
return known_settable_ctx_params;
}
const OSSL_DISPATCH ossl_rsa_asym_cipher_functions[] = {
{ OSSL_FUNC_ASYM_CIPHER_NEWCTX, (void (*)(void))rsa_newctx },
{ OSSL_FUNC_ASYM_CIPHER_ENCRYPT_INIT, (void (*)(void))rsa_encrypt_init },
{ OSSL_FUNC_ASYM_CIPHER_ENCRYPT, (void (*)(void))rsa_encrypt },
{ OSSL_FUNC_ASYM_CIPHER_DECRYPT_INIT, (void (*)(void))rsa_decrypt_init },
{ OSSL_FUNC_ASYM_CIPHER_DECRYPT, (void (*)(void))rsa_decrypt },
{ OSSL_FUNC_ASYM_CIPHER_FREECTX, (void (*)(void))rsa_freectx },
{ OSSL_FUNC_ASYM_CIPHER_DUPCTX, (void (*)(void))rsa_dupctx },
{ OSSL_FUNC_ASYM_CIPHER_GET_CTX_PARAMS,
(void (*)(void))rsa_get_ctx_params },
{ OSSL_FUNC_ASYM_CIPHER_GETTABLE_CTX_PARAMS,
(void (*)(void))rsa_gettable_ctx_params },
{ OSSL_FUNC_ASYM_CIPHER_SET_CTX_PARAMS,
(void (*)(void))rsa_set_ctx_params },
{ OSSL_FUNC_ASYM_CIPHER_SETTABLE_CTX_PARAMS,
(void (*)(void))rsa_settable_ctx_params },
OSSL_DISPATCH_END
};
