diff options
Diffstat (limited to 'third_party/libsrtp/src/crypto/cipher/null_cipher.c')
| -rw-r--r-- | third_party/libsrtp/src/crypto/cipher/null_cipher.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/third_party/libsrtp/src/crypto/cipher/null_cipher.c b/third_party/libsrtp/src/crypto/cipher/null_cipher.c new file mode 100644 index 0000000000..969724611c --- /dev/null +++ b/third_party/libsrtp/src/crypto/cipher/null_cipher.c @@ -0,0 +1,153 @@ +/* + * null_cipher.c + * + * A null cipher implementation. This cipher leaves the plaintext + * unchanged. + * + * 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. + * + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "datatypes.h" +#include "null_cipher.h" +#include "err.h" /* for srtp_debug */ +#include "alloc.h" +#include "cipher_types.h" + +static srtp_err_status_t srtp_null_cipher_alloc(srtp_cipher_t **c, + int key_len, + int tlen) +{ + extern const srtp_cipher_type_t srtp_null_cipher; + + debug_print(srtp_mod_cipher, "allocating cipher with key length %d", + key_len); + + /* allocate memory a cipher of type null_cipher */ + *c = (srtp_cipher_t *)srtp_crypto_alloc(sizeof(srtp_cipher_t)); + if (*c == NULL) { + return srtp_err_status_alloc_fail; + } + + /* set pointers */ + (*c)->algorithm = SRTP_NULL_CIPHER; + (*c)->type = &srtp_null_cipher; + (*c)->state = (void *)0x1; /* The null cipher does not maintain state */ + + /* set key size */ + (*c)->key_len = key_len; + + return srtp_err_status_ok; +} + +static srtp_err_status_t srtp_null_cipher_dealloc(srtp_cipher_t *c) +{ + extern const srtp_cipher_type_t srtp_null_cipher; + + /* zeroize entire state*/ + octet_string_set_to_zero(c, sizeof(srtp_cipher_t)); + + /* free memory of type null_cipher */ + srtp_crypto_free(c); + + return srtp_err_status_ok; +} + +static srtp_err_status_t srtp_null_cipher_init(void *cv, const uint8_t *key) +{ + /* srtp_null_cipher_ctx_t *c = (srtp_null_cipher_ctx_t *)cv; */ + + debug_print0(srtp_mod_cipher, "initializing null cipher"); + + return srtp_err_status_ok; +} + +static srtp_err_status_t srtp_null_cipher_set_iv(void *cv, + uint8_t *iv, + srtp_cipher_direction_t dir) +{ + /* srtp_null_cipher_ctx_t *c = (srtp_null_cipher_ctx_t *)cv; */ + return srtp_err_status_ok; +} + +static srtp_err_status_t srtp_null_cipher_encrypt(void *cv, + unsigned char *buf, + unsigned int *bytes_to_encr) +{ + /* srtp_null_cipher_ctx_t *c = (srtp_null_cipher_ctx_t *)cv; */ + return srtp_err_status_ok; +} + +static const char srtp_null_cipher_description[] = "null cipher"; + +static const srtp_cipher_test_case_t srtp_null_cipher_test_0 = { + 0, /* octets in key */ + NULL, /* key */ + 0, /* packet index */ + 0, /* octets in plaintext */ + NULL, /* plaintext */ + 0, /* octets in plaintext */ + NULL, /* ciphertext */ + 0, /* */ + NULL, /* */ + 0, /* */ + NULL /* pointer to next testcase */ +}; + +/* + * note: the decrypt function is idential to the encrypt function + */ + +const srtp_cipher_type_t srtp_null_cipher = { + srtp_null_cipher_alloc, /* */ + srtp_null_cipher_dealloc, /* */ + srtp_null_cipher_init, /* */ + 0, /* set_aad */ + srtp_null_cipher_encrypt, /* */ + srtp_null_cipher_encrypt, /* */ + srtp_null_cipher_set_iv, /* */ + 0, /* get_tag */ + srtp_null_cipher_description, /* */ + &srtp_null_cipher_test_0, /* */ + SRTP_NULL_CIPHER /* */ +}; |