blob: 91da561f68a30fc9355b5153d5d23a300f78321b [file] [log] [blame]
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include <limits.h>
#include <string.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include "evp_locl.h"
size_t EVP_AEAD_key_length(const EVP_AEAD *aead)
{
return aead->key_len;
}
size_t EVP_AEAD_nonce_length(const EVP_AEAD *aead)
{
return aead->nonce_len;
}
size_t EVP_AEAD_max_overhead(const EVP_AEAD *aead)
{
return aead->overhead;
}
size_t EVP_AEAD_max_tag_len(const EVP_AEAD *aead)
{
return aead->max_tag_len;
}
int EVP_AEAD_CTX_init(EVP_AEAD_CTX *ctx, const EVP_AEAD *aead,
const unsigned char *key, size_t key_len,
size_t tag_len, ENGINE *impl)
{
ctx->aead = aead;
if (key_len != aead->key_len)
{
EVPerr(EVP_F_EVP_AEAD_CTX_INIT,EVP_R_UNSUPPORTED_KEY_SIZE);
return 0;
}
return aead->init(ctx, key, key_len, tag_len);
}
void EVP_AEAD_CTX_cleanup(EVP_AEAD_CTX *ctx)
{
if (ctx->aead == NULL)
return;
ctx->aead->cleanup(ctx);
ctx->aead = NULL;
}
/* check_alias returns 0 if |out| points within the buffer determined by |in|
* and |in_len| and 1 otherwise.
*
* When processing, there's only an issue if |out| points within in[:in_len]
* and isn't equal to |in|. If that's the case then writing the output will
* stomp input that hasn't been read yet.
*
* This function checks for that case. */
static int check_alias(const unsigned char *in, size_t in_len,
const unsigned char *out)
{
if (out <= in)
return 1;
if (in + in_len <= out)
return 1;
return 0;
}
ssize_t EVP_AEAD_CTX_seal(const EVP_AEAD_CTX *ctx,
unsigned char *out, size_t max_out_len,
const unsigned char *nonce, size_t nonce_len,
const unsigned char *in, size_t in_len,
const unsigned char *ad, size_t ad_len)
{
size_t possible_out_len = in_len + ctx->aead->overhead;
ssize_t r;
if (possible_out_len < in_len /* overflow */ ||
possible_out_len > SSIZE_MAX /* return value cannot be
represented */)
{
EVPerr(EVP_F_AEAD_CTX_SEAL, EVP_R_TOO_LARGE);
goto error;
}
if (!check_alias(in, in_len, out))
{
EVPerr(EVP_F_AEAD_CTX_SEAL, EVP_R_OUTPUT_ALIASES_INPUT);
goto error;
}
r = ctx->aead->seal(ctx, out, max_out_len, nonce, nonce_len,
in, in_len, ad, ad_len);
if (r >= 0)
return r;
error:
/* In the event of an error, clear the output buffer so that a caller
* that doesn't check the return value doesn't send raw data. */
memset(out, 0, max_out_len);
return -1;
}
ssize_t EVP_AEAD_CTX_open(const EVP_AEAD_CTX *ctx,
unsigned char *out, size_t max_out_len,
const unsigned char *nonce, size_t nonce_len,
const unsigned char *in, size_t in_len,
const unsigned char *ad, size_t ad_len)
{
ssize_t r;
if (in_len > SSIZE_MAX)
{
EVPerr(EVP_F_AEAD_CTX_OPEN, EVP_R_TOO_LARGE);
goto error; /* may not be able to represent return value. */
}
if (!check_alias(in, in_len, out))
{
EVPerr(EVP_F_AEAD_CTX_OPEN, EVP_R_OUTPUT_ALIASES_INPUT);
goto error;
}
r = ctx->aead->open(ctx, out, max_out_len, nonce, nonce_len,
in, in_len, ad, ad_len);
if (r >= 0)
return r;
error:
/* In the event of an error, clear the output buffer so that a caller
* that doesn't check the return value doesn't try and process bad
* data. */
memset(out, 0, max_out_len);
return -1;
}