boringssl/include/openssl/hkdf.h
David Benjamin edd65fb132 Const-correct HKDF_expand.
prk should be a const parameter.

Change-Id: I2369ed9f87fc3c59afc07d3b667b86aec340052e
Reviewed-on: https://boringssl-review.googlesource.com/8810
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-07-16 07:55:19 +00:00

65 lines
2.7 KiB
C

/* Copyright (c) 2014, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#ifndef OPENSSL_HEADER_HKDF_H
#define OPENSSL_HEADER_HKDF_H
#include <openssl/base.h>
#if defined(__cplusplus)
extern "C" {
#endif
/* HKDF. */
/* HKDF computes HKDF (as specified by RFC 5869) of initial keying material
* |secret| with |salt| and |info| using |digest|, and outputs |out_len| bytes
* to |out_key|. It returns one on success and zero on error.
*
* HKDF is an Extract-and-Expand algorithm. It does not do any key stretching,
* and as such, is not suited to be used alone to generate a key from a
* password. */
OPENSSL_EXPORT int HKDF(uint8_t *out_key, size_t out_len, const EVP_MD *digest,
const uint8_t *secret, size_t secret_len,
const uint8_t *salt, size_t salt_len,
const uint8_t *info, size_t info_len);
/* HKDF_extract computes a HKDF PRK (as specified by RFC 5869) from initial
* keying material |secret| and salt |salt| using |digest|, and outputs
* |out_len| bytes to |out_key|. The maximum output size is |EVP_MAX_MD_SIZE|.
* It returns one on success and zero on error. */
OPENSSL_EXPORT int HKDF_extract(uint8_t *out_key, size_t *out_len,
const EVP_MD *digest, const uint8_t *secret,
size_t secret_len, const uint8_t *salt,
size_t salt_len);
/* HKDF_expand computes a HKDF OKM (as specified by RFC 5869) of length
* |out_len| from the PRK |prk| and info |info| using |digest|, and outputs
* the result to |out_key|. It returns one on success and zero on error. */
OPENSSL_EXPORT int HKDF_expand(uint8_t *out_key, size_t out_len,
const EVP_MD *digest, const uint8_t *prk,
size_t prk_len, const uint8_t *info,
size_t info_len);
#if defined(__cplusplus)
} /* extern C */
#endif
#define HKDF_R_OUTPUT_TOO_LARGE 100
#endif /* OPENSSL_HEADER_HKDF_H */