tc/crypto/Aes.h

   1 /*
   2  ---------------------------------------------------------------------------
   3  Copyright (c) 1998-2007, Brian Gladman, Worcester, UK. All rights reserved.
   4
   5  LICENSE TERMS
   6
   7  The free distribution and use of this software is allowed (with or without
   8  changes) provided that:
   9
  10   1. source code distributions include the above copyright notice, this
  11      list of conditions and the following disclaimer;
  12
  13   2. binary distributions include the above copyright notice, this list
  14      of conditions and the following disclaimer in their documentation;
  15
  16   3. the name of the copyright holder is not used to endorse products
  17      built using this software without specific written permission.
  18
  19  DISCLAIMER
  20
  21  This software is provided 'as is' with no explicit or implied warranties
  22  in respect of its properties, including, but not limited to, correctness
  23  and/or fitness for purpose.
  24  ---------------------------------------------------------------------------
  25  Issue Date: 20/12/2007
  26
  27  This file contains the definitions required to use AES in C. See aesopt.h
  28  for optimisation details.
  29 */
  30
  31 /* Adapted by the TrueCrypt Foundation */
  32
  33 #ifndef _AES_H
  34 #define _AES_H
  35
  36 #include "Common/Tcdefs.h"
  37
  38 #ifndef EXIT_SUCCESS
  39 #define EXIT_SUCCESS    0
  40 #define EXIT_FAILURE    1
  41 #endif
  42 #define INT_RETURN   int
  43
  44 #if defined(__cplusplus)
  45 extern "C"
  46 {
  47 #endif
  48
  49 // #define AES_128     /* define if AES with 128 bit keys is needed    */
  50 // #define AES_192     /* define if AES with 192 bit keys is needed    */
  51 #define AES_256     /* define if AES with 256 bit keys is needed    */
  52 // #define AES_VAR     /* define if a variable key size is needed      */
  53 // #define AES_MODES   /* define if support is needed for modes        */
  54
  55 /* The following must also be set in assembler files if being used  */
  56
  57 #define AES_ENCRYPT /* if support for encryption is needed          */
  58 #define AES_DECRYPT /* if support for decryption is needed          */
  59 #define AES_ERR_CHK /* for parameter checks & error return codes    */
  60 #define AES_REV_DKS /* define to reverse decryption key schedule    */
  61
  62 #define AES_BLOCK_SIZE  16  /* the AES block size in bytes          */
  63 #define N_COLS           4  /* the number of columns in the state   */
  64
  65 /* The key schedule length is 11, 13 or 15 16-byte blocks for 128,  */
  66 /* 192 or 256-bit keys respectively. That is 176, 208 or 240 bytes  */
  67 /* or 44, 52 or 60 32-bit words.                                    */
  68
  69 #if defined( AES_VAR ) || defined( AES_256 )
  70 #define KS_LENGTH       60
  71 #elif defined( AES_192 )
  72 #define KS_LENGTH       52
  73 #else
  74 #define KS_LENGTH       44
  75 #endif
  76
  77 #if defined( AES_ERR_CHK )
  78 #define AES_RETURN     INT_RETURN
  79 #else
  80 #define AES_RETURN     VOID_RETURN
  81 #endif
  82
  83 /* the character array 'inf' in the following structures is used    */
  84 /* to hold AES context information. This AES code uses cx->inf.b[0] */
  85 /* to hold the number of rounds multiplied by 16. The other three   */
  86 /* elements can be used by code that implements additional modes    */
  87
  88 typedef union
  89 {   uint_32t l;
  90     uint_8t b[4];
  91 } aes_inf;
  92
  93 typedef struct
  94 {   uint_32t ks[KS_LENGTH];
  95     aes_inf inf;
  96 } aes_encrypt_ctx;
  97
  98 typedef struct
  99 {   uint_32t ks[KS_LENGTH];
 100     aes_inf inf;
 101 } aes_decrypt_ctx;
 102
 103 /* This routine must be called before first use if non-static       */
 104 /* tables are being used                                            */
 105
 106 AES_RETURN aes_init(void);
 107
 108 /* Key lengths in the range 16 <= key_len <= 32 are given in bytes, */
 109 /* those in the range 128 <= key_len <= 256 are given in bits       */
 110
 111 #if defined( AES_ENCRYPT )
 112
 113 #if defined(AES_128) || defined(AES_VAR)
 114 AES_RETURN aes_encrypt_key128(const unsigned char *key, aes_encrypt_ctx cx[1]);
 115 #endif
 116
 117 #if defined(AES_192) || defined(AES_VAR)
 118 AES_RETURN aes_encrypt_key192(const unsigned char *key, aes_encrypt_ctx cx[1]);
 119 #endif
 120
 121 #if defined(AES_256) || defined(AES_VAR)
 122 AES_RETURN aes_encrypt_key256(const unsigned char *key, aes_encrypt_ctx cx[1]);
 123 #endif
 124
 125 #if defined(AES_VAR)
 126 AES_RETURN aes_encrypt_key(const unsigned char *key, int key_len, aes_encrypt_ctx cx[1]);
 127 #endif
 128
 129 AES_RETURN aes_encrypt(const unsigned char *in, unsigned char *out, const aes_encrypt_ctx cx[1]);
 130
 131 #endif
 132
 133 #if defined( AES_DECRYPT )
 134
 135 #if defined(AES_128) || defined(AES_VAR)
 136 AES_RETURN aes_decrypt_key128(const unsigned char *key, aes_decrypt_ctx cx[1]);
 137 #endif
 138
 139 #if defined(AES_192) || defined(AES_VAR)
 140 AES_RETURN aes_decrypt_key192(const unsigned char *key, aes_decrypt_ctx cx[1]);
 141 #endif
 142
 143 #if defined(AES_256) || defined(AES_VAR)
 144 AES_RETURN aes_decrypt_key256(const unsigned char *key, aes_decrypt_ctx cx[1]);
 145 #endif
 146
 147 #if defined(AES_VAR)
 148 AES_RETURN aes_decrypt_key(const unsigned char *key, int key_len, aes_decrypt_ctx cx[1]);
 149 #endif
 150
 151 AES_RETURN aes_decrypt(const unsigned char *in, unsigned char *out, const aes_decrypt_ctx cx[1]);
 152
 153 #endif
 154
 155 #if defined(AES_MODES)
 156
 157 /* Multiple calls to the following subroutines for multiple block   */
 158 /* ECB, CBC, CFB, OFB and CTR mode encryption can be used to handle */
 159 /* long messages incremantally provided that the context AND the iv */
 160 /* are preserved between all such calls.  For the ECB and CBC modes */
 161 /* each individual call within a series of incremental calls must   */
 162 /* process only full blocks (i.e. len must be a multiple of 16) but */
 163 /* the CFB, OFB and CTR mode calls can handle multiple incremental  */
 164 /* calls of any length. Each mode is reset when a new AES key is    */
 165 /* set but ECB and CBC operations can be reset without setting a    */
 166 /* new key by setting a new IV value.  To reset CFB, OFB and CTR    */
 167 /* without setting the key, aes_mode_reset() must be called and the */
 168 /* IV must be set.  NOTE: All these calls update the IV on exit so  */
 169 /* this has to be reset if a new operation with the same IV as the  */
 170 /* previous one is required (or decryption follows encryption with  */
 171 /* the same IV array).                                              */
 172
 173 AES_RETURN aes_test_alignment_detection(unsigned int n);
 174
 175 AES_RETURN aes_ecb_encrypt(const unsigned char *ibuf, unsigned char *obuf,
 176                     int len, const aes_encrypt_ctx cx[1]);
 177
 178 AES_RETURN aes_ecb_decrypt(const unsigned char *ibuf, unsigned char *obuf,
 179                     int len, const aes_decrypt_ctx cx[1]);
 180
 181 AES_RETURN aes_cbc_encrypt(const unsigned char *ibuf, unsigned char *obuf,
 182                     int len, unsigned char *iv, const aes_encrypt_ctx cx[1]);
 183
 184 AES_RETURN aes_cbc_decrypt(const unsigned char *ibuf, unsigned char *obuf,
 185                     int len, unsigned char *iv, const aes_decrypt_ctx cx[1]);
 186
 187 AES_RETURN aes_mode_reset(aes_encrypt_ctx cx[1]);
 188
 189 AES_RETURN aes_cfb_encrypt(const unsigned char *ibuf, unsigned char *obuf,
 190                     int len, unsigned char *iv, aes_encrypt_ctx cx[1]);
 191
 192 AES_RETURN aes_cfb_decrypt(const unsigned char *ibuf, unsigned char *obuf,
 193                     int len, unsigned char *iv, aes_encrypt_ctx cx[1]);
 194
 195 #define aes_ofb_encrypt aes_ofb_crypt
 196 #define aes_ofb_decrypt aes_ofb_crypt
 197
 198 AES_RETURN aes_ofb_crypt(const unsigned char *ibuf, unsigned char *obuf,
 199                     int len, unsigned char *iv, aes_encrypt_ctx cx[1]);
 200
 201 typedef void cbuf_inc(unsigned char *cbuf);
 202
 203 #define aes_ctr_encrypt aes_ctr_crypt
 204 #define aes_ctr_decrypt aes_ctr_crypt
 205
 206 AES_RETURN aes_ctr_crypt(const unsigned char *ibuf, unsigned char *obuf,
 207             int len, unsigned char *cbuf, cbuf_inc ctr_inc, aes_encrypt_ctx cx[1]);
 208
 209 #endif
 210
 211 #if defined(__cplusplus)
 212 }
 213 #endif
 214
 215 #endif