openssl/crypto/ec/ecdh_kdf.c
Pauli 8b6ffd4040 Params: change UTF8 construct calls to avoid explicit strlen(3) calls.
It is better, safer and smaller to let the library routine handle the
strlen(3) call.

Added a note to the documentation suggesting this.

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11019)
2020-02-06 16:22:00 +10:00

65 lines
2.1 KiB
C

/*
* Copyright 2015-2019 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
*/
/*
* ECDH low level APIs are deprecated for public use, but still ok for
* internal use.
*/
#include "internal/deprecated.h"
#include <string.h>
#include <openssl/core_names.h>
#include <openssl/ec.h>
#include <openssl/evp.h>
#include <openssl/kdf.h>
#include "ec_local.h"
/* Key derivation function from X9.63/SECG */
int ecdh_KDF_X9_63(unsigned char *out, size_t outlen,
const unsigned char *Z, size_t Zlen,
const unsigned char *sinfo, size_t sinfolen,
const EVP_MD *md)
{
int ret = 0;
EVP_KDF_CTX *kctx = NULL;
OSSL_PARAM params[4], *p = params;
const char *mdname = EVP_MD_name(md);
EVP_KDF *kdf = EVP_KDF_fetch(NULL, OSSL_KDF_NAME_X963KDF, NULL);
if ((kctx = EVP_KDF_CTX_new(kdf)) != NULL) {
*p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
(char *)mdname, 0);
*p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
(void *)Z, Zlen);
*p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_INFO,
(void *)sinfo, sinfolen);
*p = OSSL_PARAM_construct_end();
ret = EVP_KDF_CTX_set_params(kctx, params) > 0
&& EVP_KDF_derive(kctx, out, outlen) > 0;
EVP_KDF_CTX_free(kctx);
}
EVP_KDF_free(kdf);
return ret;
}
/*-
* The old name for ecdh_KDF_X9_63
* Retained for ABI compatibility
*/
#ifndef OPENSSL_NO_DEPRECATED_3_0
int ECDH_KDF_X9_62(unsigned char *out, size_t outlen,
const unsigned char *Z, size_t Zlen,
const unsigned char *sinfo, size_t sinfolen,
const EVP_MD *md)
{
return ecdh_KDF_X9_63(out, outlen, Z, Zlen, sinfo, sinfolen, md);
}
#endif