blob: 2d567158a4ad6074517a49ac26643acbd8b4268d [file] [log] [blame]
/* 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. */
#include <openssl/aead.h>
#include <string.h>
#include <openssl/cipher.h>
#include <openssl/err.h>
#include "internal.h"
#include "../internal.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; }
void EVP_AEAD_CTX_zero(EVP_AEAD_CTX *ctx) {
memset(ctx, 0, sizeof(EVP_AEAD_CTX));
}
int EVP_AEAD_CTX_init(EVP_AEAD_CTX *ctx, const EVP_AEAD *aead,
const uint8_t *key, size_t key_len, size_t tag_len,
ENGINE *impl) {
if (!aead->init) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_NO_DIRECTION_SET);
ctx->aead = NULL;
return 0;
}
return EVP_AEAD_CTX_init_with_direction(ctx, aead, key, key_len, tag_len,
evp_aead_open);
}
int EVP_AEAD_CTX_init_with_direction(EVP_AEAD_CTX *ctx, const EVP_AEAD *aead,
const uint8_t *key, size_t key_len,
size_t tag_len,
enum evp_aead_direction_t dir) {
if (key_len != aead->key_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_KEY_SIZE);
ctx->aead = NULL;
return 0;
}
ctx->aead = aead;
int ok;
if (aead->init) {
ok = aead->init(ctx, key, key_len, tag_len);
} else {
ok = aead->init_with_direction(ctx, key, key_len, tag_len, dir);
}
if (!ok) {
ctx->aead = NULL;
}
return ok;
}
void EVP_AEAD_CTX_cleanup(EVP_AEAD_CTX *ctx) {
if (ctx->aead == NULL) {
return;
}
ctx->aead->cleanup(ctx);
ctx->aead = NULL;
}
/* check_alias returns 1 if |out| is compatible with |in| and 0 otherwise. If
* |in| and |out| alias, we require that |in| == |out|. */
static int check_alias(const uint8_t *in, size_t in_len, const uint8_t *out,
size_t out_len) {
if (!buffers_alias(in, in_len, out, out_len)) {
return 1;
}
return in == out;
}
int EVP_AEAD_CTX_seal(const EVP_AEAD_CTX *ctx, uint8_t *out, size_t *out_len,
size_t max_out_len, const uint8_t *nonce,
size_t nonce_len, const uint8_t *in, size_t in_len,
const uint8_t *ad, size_t ad_len) {
size_t possible_out_len = in_len + ctx->aead->overhead;
if (possible_out_len < in_len /* overflow */) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE);
goto error;
}
if (!check_alias(in, in_len, out, max_out_len)) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_OUTPUT_ALIASES_INPUT);
goto error;
}
if (ctx->aead->seal(ctx, out, out_len, max_out_len, nonce, nonce_len, in,
in_len, ad, ad_len)) {
return 1;
}
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);
*out_len = 0;
return 0;
}
int EVP_AEAD_CTX_open(const EVP_AEAD_CTX *ctx, uint8_t *out, size_t *out_len,
size_t max_out_len, const uint8_t *nonce,
size_t nonce_len, const uint8_t *in, size_t in_len,
const uint8_t *ad, size_t ad_len) {
if (!check_alias(in, in_len, out, max_out_len)) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_OUTPUT_ALIASES_INPUT);
goto error;
}
if (ctx->aead->open(ctx, out, out_len, max_out_len, nonce, nonce_len, in,
in_len, ad, ad_len)) {
return 1;
}
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);
*out_len = 0;
return 0;
}
const EVP_AEAD *EVP_AEAD_CTX_aead(const EVP_AEAD_CTX *ctx) { return ctx->aead; }
int EVP_AEAD_CTX_get_iv(const EVP_AEAD_CTX *ctx, const uint8_t **out_iv,
size_t *out_len) {
if (ctx->aead->get_iv == NULL) {
return 0;
}
return ctx->aead->get_iv(ctx, out_iv, out_len);
}