249 lines
9.4 KiB
C
249 lines
9.4 KiB
C
|
/*
|
||
|
|
* cipher.h
|
||
|
|
*
|
||
|
|
* common interface to ciphers
|
||
|
|
*
|
||
|
|
* David A. McGrew
|
||
|
|
* Cisco Systems, Inc.
|
||
|
|
*/
|
||
|
|
/*
|
||
|
|
*
|
||
|
|
* Copyright (c) 2001-2017 Cisco Systems, Inc.
|
||
|
|
* All rights reserved.
|
||
|
|
*
|
||
|
|
* Redistribution and use in source and binary forms, with or without
|
||
|
|
* modification, are permitted provided that the following conditions
|
||
|
|
* are met:
|
||
|
|
*
|
||
|
|
* Redistributions of source code must retain the above copyright
|
||
|
|
* notice, this list of conditions and the following disclaimer.
|
||
|
|
*
|
||
|
|
* 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.
|
||
|
|
*
|
||
|
|
* Neither the name of the Cisco Systems, Inc. nor the names of its
|
||
|
|
* contributors may be used to endorse or promote products derived
|
||
|
|
* from this software without specific prior written permission.
|
||
|
|
*
|
||
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||
|
|
* "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
|
||
|
|
* COPYRIGHT HOLDERS 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.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef SRTP_CIPHER_H
|
||
|
|
#define SRTP_CIPHER_H
|
||
|
|
|
||
|
|
#include "srtp.h"
|
||
|
|
#include "crypto_types.h" /* for values of cipher_type_id_t */
|
||
|
|
|
||
|
|
#ifdef __cplusplus
|
||
|
|
extern "C" {
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* srtp_cipher_direction_t defines a particular cipher operation.
|
||
|
|
*
|
||
|
|
* A srtp_cipher_direction_t is an enum that describes a particular cipher
|
||
|
|
* operation, i.e. encryption or decryption. For some ciphers, this
|
||
|
|
* distinction does not matter, but for others, it is essential.
|
||
|
|
*/
|
||
|
|
typedef enum {
|
||
|
|
srtp_direction_encrypt, /**< encryption (convert plaintext to ciphertext) */
|
||
|
|
srtp_direction_decrypt, /**< decryption (convert ciphertext to plaintext) */
|
||
|
|
srtp_direction_any /**< encryption or decryption */
|
||
|
|
} srtp_cipher_direction_t;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* the srtp_cipher_pointer_t definition is needed
|
||
|
|
* as srtp_cipher_t is not yet defined
|
||
|
|
*/
|
||
|
|
typedef struct srtp_cipher_t *srtp_cipher_pointer_t;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* a srtp_cipher_alloc_func_t allocates (but does not initialize) a
|
||
|
|
* srtp_cipher_t
|
||
|
|
*/
|
||
|
|
typedef srtp_err_status_t (*srtp_cipher_alloc_func_t)(srtp_cipher_pointer_t *cp,
|
||
|
|
int key_len,
|
||
|
|
int tag_len);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* a srtp_cipher_init_func_t [re-]initializes a cipher_t with a given key
|
||
|
|
*/
|
||
|
|
typedef srtp_err_status_t (*srtp_cipher_init_func_t)(void *state,
|
||
|
|
const uint8_t *key);
|
||
|
|
|
||
|
|
/* a srtp_cipher_dealloc_func_t de-allocates a cipher_t */
|
||
|
|
typedef srtp_err_status_t (*srtp_cipher_dealloc_func_t)(
|
||
|
|
srtp_cipher_pointer_t cp);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* a srtp_cipher_set_aad_func_t processes the AAD data for AEAD ciphers
|
||
|
|
*/
|
||
|
|
typedef srtp_err_status_t (*srtp_cipher_set_aad_func_t)(void *state,
|
||
|
|
const uint8_t *aad,
|
||
|
|
uint32_t aad_len);
|
||
|
|
|
||
|
|
/* a srtp_cipher_encrypt_func_t encrypts data in-place */
|
||
|
|
typedef srtp_err_status_t (*srtp_cipher_encrypt_func_t)(
|
||
|
|
void *state,
|
||
|
|
uint8_t *buffer,
|
||
|
|
unsigned int *octets_to_encrypt);
|
||
|
|
|
||
|
|
/* a srtp_cipher_decrypt_func_t decrypts data in-place */
|
||
|
|
typedef srtp_err_status_t (*srtp_cipher_decrypt_func_t)(
|
||
|
|
void *state,
|
||
|
|
uint8_t *buffer,
|
||
|
|
unsigned int *octets_to_decrypt);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* a srtp_cipher_set_iv_func_t function sets the current initialization vector
|
||
|
|
*/
|
||
|
|
typedef srtp_err_status_t (*srtp_cipher_set_iv_func_t)(
|
||
|
|
void *state,
|
||
|
|
uint8_t *iv,
|
||
|
|
srtp_cipher_direction_t direction);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* a cipher_get_tag_func_t function is used to get the authentication
|
||
|
|
* tag that was calculated by an AEAD cipher.
|
||
|
|
*/
|
||
|
|
typedef srtp_err_status_t (*srtp_cipher_get_tag_func_t)(void *state,
|
||
|
|
uint8_t *tag,
|
||
|
|
uint32_t *len);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* srtp_cipher_test_case_t is a (list of) key, salt, plaintext, ciphertext,
|
||
|
|
* and aad values that are known to be correct for a
|
||
|
|
* particular cipher. this data can be used to test an implementation
|
||
|
|
* in an on-the-fly self test of the correctness of the implementation.
|
||
|
|
* (see the srtp_cipher_type_self_test() function below)
|
||
|
|
*/
|
||
|
|
typedef struct srtp_cipher_test_case_t {
|
||
|
|
int key_length_octets; /* octets in key */
|
||
|
|
const uint8_t *key; /* key */
|
||
|
|
uint8_t *idx; /* packet index */
|
||
|
|
unsigned int plaintext_length_octets; /* octets in plaintext */
|
||
|
|
const uint8_t *plaintext; /* plaintext */
|
||
|
|
unsigned int ciphertext_length_octets; /* octets in plaintext */
|
||
|
|
const uint8_t *ciphertext; /* ciphertext */
|
||
|
|
int aad_length_octets; /* octets in AAD */
|
||
|
|
const uint8_t *aad; /* AAD */
|
||
|
|
int tag_length_octets; /* Length of AEAD tag */
|
||
|
|
const struct srtp_cipher_test_case_t
|
||
|
|
*next_test_case; /* pointer to next testcase */
|
||
|
|
} srtp_cipher_test_case_t;
|
||
|
|
|
||
|
|
/* srtp_cipher_type_t defines the 'metadata' for a particular cipher type */
|
||
|
|
typedef struct srtp_cipher_type_t {
|
||
|
|
srtp_cipher_alloc_func_t alloc;
|
||
|
|
srtp_cipher_dealloc_func_t dealloc;
|
||
|
|
srtp_cipher_init_func_t init;
|
||
|
|
srtp_cipher_set_aad_func_t set_aad;
|
||
|
|
srtp_cipher_encrypt_func_t encrypt;
|
||
|
|
srtp_cipher_encrypt_func_t decrypt;
|
||
|
|
srtp_cipher_set_iv_func_t set_iv;
|
||
|
|
srtp_cipher_get_tag_func_t get_tag;
|
||
|
|
const char *description;
|
||
|
|
const srtp_cipher_test_case_t *test_data;
|
||
|
|
srtp_cipher_type_id_t id;
|
||
|
|
} srtp_cipher_type_t;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* srtp_cipher_t defines an instantiation of a particular cipher, with fixed
|
||
|
|
* key length, key and salt values
|
||
|
|
*/
|
||
|
|
typedef struct srtp_cipher_t {
|
||
|
|
const srtp_cipher_type_t *type;
|
||
|
|
void *state;
|
||
|
|
int key_len;
|
||
|
|
int algorithm;
|
||
|
|
} srtp_cipher_t;
|
||
|
|
|
||
|
|
/* some bookkeeping functions */
|
||
|
|
int srtp_cipher_get_key_length(const srtp_cipher_t *c);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* srtp_cipher_type_self_test() tests a cipher against test cases provided in
|
||
|
|
* an array of values of key/srtp_xtd_seq_num_t/plaintext/ciphertext
|
||
|
|
* that is known to be good
|
||
|
|
*/
|
||
|
|
srtp_err_status_t srtp_cipher_type_self_test(const srtp_cipher_type_t *ct);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* srtp_cipher_type_test() tests a cipher against external test cases provided
|
||
|
|
* in
|
||
|
|
* an array of values of key/srtp_xtd_seq_num_t/plaintext/ciphertext
|
||
|
|
* that is known to be good
|
||
|
|
*/
|
||
|
|
srtp_err_status_t srtp_cipher_type_test(
|
||
|
|
const srtp_cipher_type_t *ct,
|
||
|
|
const srtp_cipher_test_case_t *test_data);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* srtp_cipher_bits_per_second(c, l, t) computes (an estimate of) the
|
||
|
|
* number of bits that a cipher implementation can encrypt in a second
|
||
|
|
*
|
||
|
|
* c is a cipher (which MUST be allocated and initialized already), l
|
||
|
|
* is the length in octets of the test data to be encrypted, and t is
|
||
|
|
* the number of trials
|
||
|
|
*
|
||
|
|
* if an error is encountered, then the value 0 is returned
|
||
|
|
*/
|
||
|
|
uint64_t srtp_cipher_bits_per_second(srtp_cipher_t *c,
|
||
|
|
int octets_in_buffer,
|
||
|
|
int num_trials);
|
||
|
|
|
||
|
|
srtp_err_status_t srtp_cipher_type_alloc(const srtp_cipher_type_t *ct,
|
||
|
|
srtp_cipher_t **c,
|
||
|
|
int key_len,
|
||
|
|
int tlen);
|
||
|
|
srtp_err_status_t srtp_cipher_dealloc(srtp_cipher_t *c);
|
||
|
|
srtp_err_status_t srtp_cipher_init(srtp_cipher_t *c, const uint8_t *key);
|
||
|
|
srtp_err_status_t srtp_cipher_set_iv(srtp_cipher_t *c,
|
||
|
|
uint8_t *iv,
|
||
|
|
int direction);
|
||
|
|
srtp_err_status_t srtp_cipher_output(srtp_cipher_t *c,
|
||
|
|
uint8_t *buffer,
|
||
|
|
uint32_t *num_octets_to_output);
|
||
|
|
srtp_err_status_t srtp_cipher_encrypt(srtp_cipher_t *c,
|
||
|
|
uint8_t *buffer,
|
||
|
|
uint32_t *num_octets_to_output);
|
||
|
|
srtp_err_status_t srtp_cipher_decrypt(srtp_cipher_t *c,
|
||
|
|
uint8_t *buffer,
|
||
|
|
uint32_t *num_octets_to_output);
|
||
|
|
srtp_err_status_t srtp_cipher_get_tag(srtp_cipher_t *c,
|
||
|
|
uint8_t *buffer,
|
||
|
|
uint32_t *tag_len);
|
||
|
|
srtp_err_status_t srtp_cipher_set_aad(srtp_cipher_t *c,
|
||
|
|
const uint8_t *aad,
|
||
|
|
uint32_t aad_len);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* srtp_replace_cipher_type(ct, id)
|
||
|
|
*
|
||
|
|
* replaces srtp's existing cipher implementation for the cipher_type id
|
||
|
|
* with a new one passed in externally. The new cipher must pass all the
|
||
|
|
* existing cipher_type's self tests as well as its own.
|
||
|
|
*/
|
||
|
|
srtp_err_status_t srtp_replace_cipher_type(const srtp_cipher_type_t *ct,
|
||
|
|
srtp_cipher_type_id_t id);
|
||
|
|
|
||
|
|
#ifdef __cplusplus
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#endif /* SRTP_CIPHER_H */
|