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- /* 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"
-
-
- 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 uint8_t *key, size_t key_len, size_t tag_len,
- ENGINE *impl) {
- if (!aead->init) {
- OPENSSL_PUT_ERROR(CIPHER, EVP_AEAD_CTX_init, 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, EVP_AEAD_CTX_init_with_direction,
- 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 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 uint8_t *in, size_t in_len, const uint8_t *out) {
- if (out <= in) {
- return 1;
- } else if (in + in_len <= out) {
- return 1;
- }
- return 0;
- }
-
- 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, EVP_AEAD_CTX_seal, CIPHER_R_TOO_LARGE);
- goto error;
- }
-
- if (!check_alias(in, in_len, out)) {
- OPENSSL_PUT_ERROR(CIPHER, EVP_AEAD_CTX_seal, 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)) {
- OPENSSL_PUT_ERROR(CIPHER, EVP_AEAD_CTX_open, 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;
- }
-
- int EVP_AEAD_CTX_get_rc4_state(const EVP_AEAD_CTX *ctx, const RC4_KEY **out_key) {
- if (ctx->aead->get_rc4_state == NULL) {
- return 0;
- }
-
- return ctx->aead->get_rc4_state(ctx, out_key);
- }
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