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* common interface to ciphers
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* Copyright (c) 2001-2006, Cisco Systems, Inc.
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* All rights reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials provided
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* with the distribution.
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* Neither the name of the Cisco Systems, Inc. nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "datatypes.h"
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#include "rdbx.h" /* for xtd_seq_num_t */
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#include "err.h" /* for error codes */
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* @brief cipher_direction_t defines a particular cipher operation.
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* A cipher_direction_t is an enum that describes a particular cipher
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* operation, i.e. encryption or decryption. For some ciphers, this
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* distinction does not matter, but for others, it is essential.
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direction_encrypt, /**< encryption (convert plaintext to ciphertext) */
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direction_decrypt, /**< decryption (convert ciphertext to plaintext) */
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direction_any /**< encryption or decryption */
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* the cipher_pointer and cipher_type_pointer definitions are needed
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* as cipher_t and cipher_type_t are not yet defined
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typedef struct cipher_type_t *cipher_type_pointer_t;
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typedef struct cipher_t *cipher_pointer_t;
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* a cipher_alloc_func_t allocates (but does not initialize) a cipher_t
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typedef err_status_t (*cipher_alloc_func_t)
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(cipher_pointer_t *cp, int key_len);
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* a cipher_init_func_t [re-]initializes a cipher_t with a given key
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* and direction (i.e., encrypt or decrypt)
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typedef err_status_t (*cipher_init_func_t)
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(void *state, const uint8_t *key, cipher_direction_t dir);
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/* a cipher_dealloc_func_t de-allocates a cipher_t */
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typedef err_status_t (*cipher_dealloc_func_t)(cipher_pointer_t cp);
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/* a cipher_set_segment_func_t sets the segment index of a cipher_t */
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typedef err_status_t (*cipher_set_segment_func_t)
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(void *state, xtd_seq_num_t idx);
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/* a cipher_encrypt_func_t encrypts data in-place */
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typedef err_status_t (*cipher_encrypt_func_t)
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(void *state, uint8_t *buffer, unsigned int *octets_to_encrypt);
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/* a cipher_decrypt_func_t decrypts data in-place */
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typedef err_status_t (*cipher_decrypt_func_t)
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(void *state, uint8_t *buffer, unsigned int *octets_to_decrypt);
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* a cipher_set_nonce_seq_func_t function sets both the nonce
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* and the extended sequence number
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typedef err_status_t (*cipher_set_iv_func_t)
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(cipher_pointer_t cp, void *iv);
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* cipher_test_case_t is a (list of) key, salt, xtd_seq_num_t,
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* plaintext, and ciphertext values that are known to be correct for a
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* particular cipher. this data can be used to test an implementation
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* in an on-the-fly self test of the correcness of the implementation.
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* (see the cipher_type_self_test() function below)
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typedef struct cipher_test_case_t {
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int key_length_octets; /* octets in key */
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uint8_t *key; /* key */
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uint8_t *idx; /* packet index */
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unsigned int plaintext_length_octets; /* octets in plaintext */
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uint8_t *plaintext; /* plaintext */
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unsigned int ciphertext_length_octets; /* octets in plaintext */
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uint8_t *ciphertext; /* ciphertext */
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struct cipher_test_case_t *next_test_case; /* pointer to next testcase */
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} cipher_test_case_t;
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/* cipher_type_t defines the 'metadata' for a particular cipher type */
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typedef struct cipher_type_t {
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cipher_alloc_func_t alloc;
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cipher_dealloc_func_t dealloc;
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cipher_init_func_t init;
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cipher_encrypt_func_t encrypt;
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cipher_encrypt_func_t decrypt;
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cipher_set_iv_func_t set_iv;
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cipher_test_case_t *test_data;
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debug_module_t *debug;
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* cipher_t defines an instantiation of a particular cipher, with fixed
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* key length, key and salt values
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typedef struct cipher_t {
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#ifdef FORCE_64BIT_ALIGN
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/* some syntactic sugar on these function types */
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#define cipher_type_alloc(ct, c, klen) ((ct)->alloc((c), (klen)))
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#define cipher_dealloc(c) (((c)->type)->dealloc(c))
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#define cipher_init(c, k, dir) (((c)->type)->init(((c)->state), (k), (dir)))
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#define cipher_encrypt(c, buf, len) \
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(((c)->type)->encrypt(((c)->state), (buf), (len)))
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#define cipher_decrypt(c, buf, len) \
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(((c)->type)->decrypt(((c)->state), (buf), (len)))
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#define cipher_set_iv(c, n) \
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((c) ? (((c)->type)->set_iv(((cipher_pointer_t)(c)->state), (n))) : \
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err_status_no_such_op)
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cipher_output(cipher_t *c, uint8_t *buffer, int num_octets_to_output);
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/* some bookkeeping functions */
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cipher_get_key_length(const cipher_t *c);
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* cipher_type_self_test() tests a cipher against test cases provided in
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* an array of values of key/xtd_seq_num_t/plaintext/ciphertext
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* that is known to be good
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cipher_type_self_test(const cipher_type_t *ct);
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* cipher_bits_per_second(c, l, t) computes (and estimate of) the
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* number of bits that a cipher implementation can encrypt in a second
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* c is a cipher (which MUST be allocated and initialized already), l
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* is the length in octets of the test data to be encrypted, and t is
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* the number of trials
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* if an error is encountered, then the value 0 is returned
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cipher_bits_per_second(cipher_t *c, int octets_in_buffer, int num_trials);
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#endif /* CIPHER_H */