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Diffstat (limited to 'third_party/libsrtp/src/crypto/include/cipher.h')
| -rw-r--r-- | third_party/libsrtp/src/crypto/include/cipher.h | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/third_party/libsrtp/src/crypto/include/cipher.h b/third_party/libsrtp/src/crypto/include/cipher.h new file mode 100644 index 0000000000..4f14e3560f --- /dev/null +++ b/third_party/libsrtp/src/crypto/include/cipher.h @@ -0,0 +1,248 @@ +/* + * 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 */ |