netwerk/srtp/src/crypto/include/cipher.h

   1 /*
   2  * cipher.h
   3  *
   4  * common interface to ciphers
   5  *
   6  * David A. McGrew
   7  * Cisco Systems, Inc.
   8  */
   9 /*
  10  *
  11  * Copyright (c) 2001-2006, Cisco Systems, Inc.
  12  * All rights reserved.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions
  16  * are met:
  17  *
  18  *   Redistributions of source code must retain the above copyright
  19  *   notice, this list of conditions and the following disclaimer.
  20  *
  21  *   Redistributions in binary form must reproduce the above
  22  *   copyright notice, this list of conditions and the following
  23  *   disclaimer in the documentation and/or other materials provided
  24  *   with the distribution.
  25  *
  26  *   Neither the name of the Cisco Systems, Inc. nor the names of its
  27  *   contributors may be used to endorse or promote products derived
  28  *   from this software without specific prior written permission.
  29  *
  30  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  31  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  32  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  33  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  34  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  35  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  36  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  37  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  40  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  41  * OF THE POSSIBILITY OF SUCH DAMAGE.
  42  *
  43  */
  44
  45
  46 #ifndef CIPHER_H
  47 #define CIPHER_H
  48
  49 #include "datatypes.h"
  50 #include "rdbx.h"               /* for xtd_seq_num_t */
  51 #include "err.h"                /* for error codes  */
  52 #include "crypto.h"             /* for cipher_type_id_t */
  53 #include "crypto_types.h"       /* for values of cipher_type_id_t */
  54
  55
  56 /**
  57  * @brief cipher_direction_t defines a particular cipher operation.
  58  *
  59  * A cipher_direction_t is an enum that describes a particular cipher
  60  * operation, i.e. encryption or decryption.  For some ciphers, this
  61  * distinction does not matter, but for others, it is essential.
  62  */
  63
  64 typedef enum {
  65   direction_encrypt, /**< encryption (convert plaintext to ciphertext) */
  66   direction_decrypt, /**< decryption (convert ciphertext to plaintext) */
  67   direction_any      /**< encryption or decryption                     */
  68 } cipher_direction_t;
  69
  70 /*
  71  * the cipher_pointer and cipher_type_pointer definitions are needed
  72  * as cipher_t and cipher_type_t are not yet defined
  73  */
  74
  75 typedef struct cipher_type_t *cipher_type_pointer_t;
  76 typedef struct cipher_t      *cipher_pointer_t;
  77
  78 /*
  79  *  a cipher_alloc_func_t allocates (but does not initialize) a cipher_t
  80  */
  81
  82 typedef err_status_t (*cipher_alloc_func_t)
  83      (cipher_pointer_t *cp, int key_len);
  84
  85 /*
  86  * a cipher_init_func_t [re-]initializes a cipher_t with a given key
  87  * and direction (i.e., encrypt or decrypt)
  88  */
  89
  90 typedef err_status_t (*cipher_init_func_t)
  91 (void *state, const uint8_t *key, int key_len, cipher_direction_t dir);
  92
  93 /* a cipher_dealloc_func_t de-allocates a cipher_t */
  94
  95 typedef err_status_t (*cipher_dealloc_func_t)(cipher_pointer_t cp);
  96
  97 /* a cipher_set_segment_func_t sets the segment index of a cipher_t */
  98
  99 typedef err_status_t (*cipher_set_segment_func_t)
 100      (void *state, xtd_seq_num_t idx);
 101
 102 /* a cipher_encrypt_func_t encrypts data in-place */
 103
 104 typedef err_status_t (*cipher_encrypt_func_t)
 105      (void *state, uint8_t *buffer, unsigned int *octets_to_encrypt);
 106
 107 /* a cipher_decrypt_func_t decrypts data in-place */
 108
 109 typedef err_status_t (*cipher_decrypt_func_t)
 110      (void *state, uint8_t *buffer, unsigned int *octets_to_decrypt);
 111
 112 /*
 113  * a cipher_set_iv_func_t function sets the current initialization vector
 114  */
 115
 116 typedef err_status_t (*cipher_set_iv_func_t)
 117      (cipher_pointer_t cp, void *iv);
 118
 119 /*
 120  * cipher_test_case_t is a (list of) key, salt, xtd_seq_num_t,
 121  * plaintext, and ciphertext values that are known to be correct for a
 122  * particular cipher.  this data can be used to test an implementation
 123  * in an on-the-fly self test of the correcness of the implementation.
 124  * (see the cipher_type_self_test() function below)
 125  */
 126
 127 typedef struct cipher_test_case_t {
 128   int key_length_octets;                      /* octets in key            */
 129   uint8_t *key;                               /* key                      */
 130   uint8_t *idx;                               /* packet index             */
 131   int plaintext_length_octets;                /* octets in plaintext      */
 132   uint8_t *plaintext;                         /* plaintext                */
 133   int ciphertext_length_octets;               /* octets in plaintext      */
 134   uint8_t *ciphertext;                        /* ciphertext               */
 135   struct cipher_test_case_t *next_test_case;  /* pointer to next testcase */
 136 } cipher_test_case_t;
 137
 138 /* cipher_type_t defines the 'metadata' for a particular cipher type */
 139
 140 typedef struct cipher_type_t {
 141   cipher_alloc_func_t         alloc;
 142   cipher_dealloc_func_t       dealloc;
 143   cipher_init_func_t          init;
 144   cipher_encrypt_func_t       encrypt;
 145   cipher_encrypt_func_t       decrypt;
 146   cipher_set_iv_func_t        set_iv;
 147   char                       *description;
 148   int                         ref_count;
 149   cipher_test_case_t         *test_data;
 150   debug_module_t             *debug;
 151   cipher_type_id_t            id;
 152 } cipher_type_t;
 153
 154 /*
 155  * cipher_t defines an instantiation of a particular cipher, with fixed
 156  * key length, key and salt values
 157  */
 158
 159 typedef struct cipher_t {
 160   cipher_type_t *type;
 161   void          *state;
 162   int            key_len;
 163 #ifdef FORCE_64BIT_ALIGN
 164   int            pad;
 165 #endif
 166 } cipher_t;
 167
 168 /* some syntactic sugar on these function types */
 169
 170 #define cipher_type_alloc(ct, c, klen) ((ct)->alloc((c), (klen)))
 171
 172 #define cipher_dealloc(c) (((c)->type)->dealloc(c))
 173
 174 #define cipher_init(c, k, dir) (((c)->type)->init(((c)->state), (k), ((c)->key_len), (dir)))
 175
 176 #define cipher_encrypt(c, buf, len) \
 177         (((c)->type)->encrypt(((c)->state), (buf), (len)))
 178
 179 #define cipher_decrypt(c, buf, len) \
 180         (((c)->type)->decrypt(((c)->state), (buf), (len)))
 181
 182 #define cipher_set_iv(c, n)                           \
 183   ((c) ? (((c)->type)->set_iv(((cipher_pointer_t)(c)->state), (n))) :   \
 184                                 err_status_no_such_op)
 185
 186 err_status_t
 187 cipher_output(cipher_t *c, uint8_t *buffer, int num_octets_to_output);
 188
 189
 190 /* some bookkeeping functions */
 191
 192 int
 193 cipher_get_key_length(const cipher_t *c);
 194
 195
 196 /*
 197  * cipher_type_self_test() tests a cipher against test cases provided in
 198  * an array of values of key/xtd_seq_num_t/plaintext/ciphertext
 199  * that is known to be good
 200  */
 201
 202 err_status_t
 203 cipher_type_self_test(const cipher_type_t *ct);
 204
 205
 206 /*
 207  * cipher_type_test() tests a cipher against external test cases provided in
 208  * an array of values of key/xtd_seq_num_t/plaintext/ciphertext
 209  * that is known to be good
 210  */
 211
 212 err_status_t
 213 cipher_type_test(const cipher_type_t *ct, const cipher_test_case_t *test_data);
 214
 215
 216 /*
 217  * cipher_bits_per_second(c, l, t) computes (and estimate of) the
 218  * number of bits that a cipher implementation can encrypt in a second
 219  *
 220  * c is a cipher (which MUST be allocated and initialized already), l
 221  * is the length in octets of the test data to be encrypted, and t is
 222  * the number of trials
 223  *
 224  * if an error is encountered, then the value 0 is returned
 225  */
 226
 227 uint64_t
 228 cipher_bits_per_second(cipher_t *c, int octets_in_buffer, int num_trials);
 229
 230 #endif /* CIPHER_H */