hmac_prov.c
/*
* Copyright 2018-2024 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
*/
/*
* HMAC low level APIs are deprecated for public use, but still ok for internal
* use.
*/
#include "internal/deprecated.h"
#include <string.h>
#include <openssl/core_dispatch.h>
#include <openssl/core_names.h>
#include <openssl/params.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/proverr.h>
#include <openssl/err.h>
#include "internal/ssl3_cbc.h"
#include "prov/implementations.h"
#include "prov/provider_ctx.h"
#include "prov/provider_util.h"
#include "prov/providercommon.h"
#include "prov/securitycheck.h"
/*
* Forward declaration of everything implemented here. This is not strictly
* necessary for the compiler, but provides an assurance that the signatures
* of the functions in the dispatch table are correct.
*/
static OSSL_FUNC_mac_newctx_fn hmac_new;
static OSSL_FUNC_mac_dupctx_fn hmac_dup;
static OSSL_FUNC_mac_freectx_fn hmac_free;
static OSSL_FUNC_mac_gettable_ctx_params_fn hmac_gettable_ctx_params;
static OSSL_FUNC_mac_get_ctx_params_fn hmac_get_ctx_params;
static OSSL_FUNC_mac_settable_ctx_params_fn hmac_settable_ctx_params;
static OSSL_FUNC_mac_set_ctx_params_fn hmac_set_ctx_params;
static OSSL_FUNC_mac_init_fn hmac_init;
static OSSL_FUNC_mac_update_fn hmac_update;
static OSSL_FUNC_mac_final_fn hmac_final;
/* local HMAC context structure */
/* typedef EVP_MAC_IMPL */
struct hmac_data_st {
void *provctx;
HMAC_CTX *ctx; /* HMAC context */
PROV_DIGEST digest;
unsigned char *key;
size_t keylen;
/* Length of full TLS record including the MAC and any padding */
size_t tls_data_size;
unsigned char tls_header[13];
int tls_header_set;
unsigned char tls_mac_out[EVP_MAX_MD_SIZE];
size_t tls_mac_out_size;
#ifdef FIPS_MODULE
/*
* 'internal' is set to 1 if HMAC is used inside another algorithm such as a
* KDF. In this case it is the parent algorithm that is responsible for
* performing any conditional FIPS indicator related checks for the HMAC.
*/
int internal;
#endif
OSSL_FIPS_IND_DECLARE
};
static void *hmac_new(void *provctx)
{
struct hmac_data_st *macctx;
if (!ossl_prov_is_running())
return NULL;
if ((macctx = OPENSSL_zalloc(sizeof(*macctx))) == NULL
|| (macctx->ctx = HMAC_CTX_new()) == NULL) {
OPENSSL_free(macctx);
return NULL;
}
macctx->provctx = provctx;
OSSL_FIPS_IND_INIT(macctx)
return macctx;
}
static void hmac_free(void *vmacctx)
{
struct hmac_data_st *macctx = vmacctx;
if (macctx != NULL) {
HMAC_CTX_free(macctx->ctx);
ossl_prov_digest_reset(&macctx->digest);
OPENSSL_secure_clear_free(macctx->key, macctx->keylen);
OPENSSL_free(macctx);
}
}
static void *hmac_dup(void *vsrc)
{
struct hmac_data_st *src = vsrc;
struct hmac_data_st *dst;
HMAC_CTX *ctx;
if (!ossl_prov_is_running())
return NULL;
dst = hmac_new(src->provctx);
if (dst == NULL)
return NULL;
ctx = dst->ctx;
*dst = *src;
dst->ctx = ctx;
dst->key = NULL;
memset(&dst->digest, 0, sizeof(dst->digest));
if (!HMAC_CTX_copy(dst->ctx, src->ctx)
|| !ossl_prov_digest_copy(&dst->digest, &src->digest)) {
hmac_free(dst);
return NULL;
}
if (src->key != NULL) {
/* There is no "secure" OPENSSL_memdup */
dst->key = OPENSSL_secure_malloc(src->keylen > 0 ? src->keylen : 1);
if (dst->key == NULL) {
hmac_free(dst);
return 0;
}
memcpy(dst->key, src->key, src->keylen);
}
return dst;
}
static size_t hmac_size(struct hmac_data_st *macctx)
{
return HMAC_size(macctx->ctx);
}
static int hmac_block_size(struct hmac_data_st *macctx)
{
const EVP_MD *md = ossl_prov_digest_md(&macctx->digest);
if (md == NULL)
return 0;
return EVP_MD_block_size(md);
}
static int hmac_setkey(struct hmac_data_st *macctx,
const unsigned char *key, size_t keylen)
{
const EVP_MD *digest;
#ifdef FIPS_MODULE
/*
* KDF's pass a salt rather than a key,
* which is why it skips the key check unless "HMAC" is fetched directly.
*/
if (!macctx->internal) {
OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(macctx->provctx);
int approved = ossl_mac_check_key_size(keylen);
if (!approved) {
if (!OSSL_FIPS_IND_ON_UNAPPROVED(macctx, OSSL_FIPS_IND_SETTABLE0,
libctx, "HMAC", "keysize",
ossl_fips_config_hmac_key_check)) {
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
return 0;
}
}
}
#endif
if (macctx->key != NULL)
OPENSSL_secure_clear_free(macctx->key, macctx->keylen);
/* Keep a copy of the key in case we need it for TLS HMAC */
macctx->key = OPENSSL_secure_malloc(keylen > 0 ? keylen : 1);
if (macctx->key == NULL)
return 0;
memcpy(macctx->key, key, keylen);
macctx->keylen = keylen;
digest = ossl_prov_digest_md(&macctx->digest);
/* HMAC_Init_ex doesn't tolerate all zero params, so we must be careful */
if (key != NULL || (macctx->tls_data_size == 0 && digest != NULL))
return HMAC_Init_ex(macctx->ctx, key, keylen, digest,
ossl_prov_digest_engine(&macctx->digest));
return 1;
}
static int hmac_init(void *vmacctx, const unsigned char *key,
size_t keylen, const OSSL_PARAM params[])
{
struct hmac_data_st *macctx = vmacctx;
if (!ossl_prov_is_running() || !hmac_set_ctx_params(macctx, params))
return 0;
if (key != NULL)
return hmac_setkey(macctx, key, keylen);
/* Just reinit the HMAC context */
return HMAC_Init_ex(macctx->ctx, NULL, 0, NULL, NULL);
}
static int hmac_update(void *vmacctx, const unsigned char *data,
size_t datalen)
{
struct hmac_data_st *macctx = vmacctx;
if (macctx->tls_data_size > 0) {
/* We're doing a TLS HMAC */
if (!macctx->tls_header_set) {
/* We expect the first update call to contain the TLS header */
if (datalen != sizeof(macctx->tls_header))
return 0;
memcpy(macctx->tls_header, data, datalen);
macctx->tls_header_set = 1;
return 1;
}
/* macctx->tls_data_size is datalen plus the padding length */
if (macctx->tls_data_size < datalen)
return 0;
return ssl3_cbc_digest_record(ossl_prov_digest_md(&macctx->digest),
macctx->tls_mac_out,
&macctx->tls_mac_out_size,
macctx->tls_header,
data,
datalen,
macctx->tls_data_size,
macctx->key,
macctx->keylen,
0);
}
return HMAC_Update(macctx->ctx, data, datalen);
}
static int hmac_final(void *vmacctx, unsigned char *out, size_t *outl,
size_t outsize)
{
unsigned int hlen;
struct hmac_data_st *macctx = vmacctx;
if (!ossl_prov_is_running())
return 0;
if (macctx->tls_data_size > 0) {
if (macctx->tls_mac_out_size == 0)
return 0;
if (outl != NULL)
*outl = macctx->tls_mac_out_size;
memcpy(out, macctx->tls_mac_out, macctx->tls_mac_out_size);
return 1;
}
if (!HMAC_Final(macctx->ctx, out, &hlen))
return 0;
*outl = hlen;
return 1;
}
static const OSSL_PARAM known_gettable_ctx_params[] = {
OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
OSSL_PARAM_size_t(OSSL_MAC_PARAM_BLOCK_SIZE, NULL),
OSSL_FIPS_IND_GETTABLE_CTX_PARAM()
OSSL_PARAM_END
};
static const OSSL_PARAM *hmac_gettable_ctx_params(ossl_unused void *ctx,
ossl_unused void *provctx)
{
return known_gettable_ctx_params;
}
static int hmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
{
struct hmac_data_st *macctx = vmacctx;
OSSL_PARAM *p;
if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
&& !OSSL_PARAM_set_size_t(p, hmac_size(macctx)))
return 0;
if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_BLOCK_SIZE)) != NULL
&& !OSSL_PARAM_set_int(p, hmac_block_size(macctx)))
return 0;
#ifdef FIPS_MODULE
p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_FIPS_APPROVED_INDICATOR);
if (p != NULL) {
int approved = 0;
if (!macctx->internal)
approved = OSSL_FIPS_IND_GET(macctx)->approved;
if (!OSSL_PARAM_set_int(p, approved))
return 0;
}
#endif
return 1;
}
static const OSSL_PARAM known_settable_ctx_params[] = {
OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_DIGEST, NULL, 0),
OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_PROPERTIES, NULL, 0),
OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
OSSL_PARAM_int(OSSL_MAC_PARAM_DIGEST_NOINIT, NULL),
OSSL_PARAM_int(OSSL_MAC_PARAM_DIGEST_ONESHOT, NULL),
OSSL_PARAM_size_t(OSSL_MAC_PARAM_TLS_DATA_SIZE, NULL),
OSSL_FIPS_IND_SETTABLE_CTX_PARAM(OSSL_MAC_PARAM_FIPS_KEY_CHECK)
OSSL_PARAM_END
};
static const OSSL_PARAM *hmac_settable_ctx_params(ossl_unused void *ctx,
ossl_unused void *provctx)
{
return known_settable_ctx_params;
}
/*
* ALL parameters should be set before init().
*/
static int hmac_set_ctx_params(void *vmacctx, const OSSL_PARAM params[])
{
struct hmac_data_st *macctx = vmacctx;
OSSL_LIB_CTX *ctx = PROV_LIBCTX_OF(macctx->provctx);
const OSSL_PARAM *p;
if (params == NULL)
return 1;
if (!OSSL_FIPS_IND_SET_CTX_PARAM(macctx, OSSL_FIPS_IND_SETTABLE0, params,
OSSL_MAC_PARAM_FIPS_KEY_CHECK))
return 0;
if (!ossl_prov_digest_load_from_params(&macctx->digest, params, ctx))
return 0;
if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
if (p->data_type != OSSL_PARAM_OCTET_STRING)
return 0;
if (!hmac_setkey(macctx, p->data, p->data_size))
return 0;
}
if ((p = OSSL_PARAM_locate_const(params,
OSSL_MAC_PARAM_TLS_DATA_SIZE)) != NULL) {
if (!OSSL_PARAM_get_size_t(p, &macctx->tls_data_size))
return 0;
}
return 1;
}
const OSSL_DISPATCH ossl_hmac_functions[] = {
{ OSSL_FUNC_MAC_NEWCTX, (void (*)(void))hmac_new },
{ OSSL_FUNC_MAC_DUPCTX, (void (*)(void))hmac_dup },
{ OSSL_FUNC_MAC_FREECTX, (void (*)(void))hmac_free },
{ OSSL_FUNC_MAC_INIT, (void (*)(void))hmac_init },
{ OSSL_FUNC_MAC_UPDATE, (void (*)(void))hmac_update },
{ OSSL_FUNC_MAC_FINAL, (void (*)(void))hmac_final },
{ OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
(void (*)(void))hmac_gettable_ctx_params },
{ OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))hmac_get_ctx_params },
{ OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
(void (*)(void))hmac_settable_ctx_params },
{ OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))hmac_set_ctx_params },
OSSL_DISPATCH_END
};
#ifdef FIPS_MODULE
static OSSL_FUNC_mac_newctx_fn hmac_internal_new;
static void *hmac_internal_new(void *provctx)
{
struct hmac_data_st *macctx = hmac_new(provctx);
if (macctx != NULL)
macctx->internal = 1;
return macctx;
}
const OSSL_DISPATCH ossl_hmac_internal_functions[] = {
{ OSSL_FUNC_MAC_NEWCTX, (void (*)(void))hmac_internal_new },
{ OSSL_FUNC_MAC_DUPCTX, (void (*)(void))hmac_dup },
{ OSSL_FUNC_MAC_FREECTX, (void (*)(void))hmac_free },
{ OSSL_FUNC_MAC_INIT, (void (*)(void))hmac_init },
{ OSSL_FUNC_MAC_UPDATE, (void (*)(void))hmac_update },
{ OSSL_FUNC_MAC_FINAL, (void (*)(void))hmac_final },
{ OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
(void (*)(void))hmac_gettable_ctx_params },
{ OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))hmac_get_ctx_params },
{ OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
(void (*)(void))hmac_settable_ctx_params },
{ OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))hmac_set_ctx_params },
OSSL_DISPATCH_END
};
#endif /* FIPS_MODULE */
