Asterisk.org: Developer Documentation (28 Oct 2009)

Wed Oct 28 15:47:47 2009

## Asterisk developer's documentation

# aes.h

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    00001 /*
    00002  * Asterisk -- An open source telephony toolkit.
    00003  *
    00004  * See http://www.asterisk.org for more information about
    00005  * the Asterisk project. Please do not directly contact
    00006  * any of the maintainers of this project for assistance;
    00007  * the project provides a web site, mailing lists and IRC
    00008  * channels for your use.
    00009  */
    00010
    00011 /*
    00012  ---------------------------------------------------------------------------
    00013  Copyright (c) 2003, Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK.
    00014  All rights reserved.
    00015
    00016  LICENSE TERMS
    00017
    00018  The free distribution and use of this software in both source and binary
    00019  form is allowed (with or without changes) provided that:
    00020
    00021    1. distributions of this source code include the above copyright
    00022       notice, this list of conditions and the following disclaimer;
    00023
    00024    2. distributions in binary form include the above copyright
    00025       notice, this list of conditions and the following disclaimer
    00026       in the documentation and/or other associated materials;
    00027
    00028    3. the copyright holder's name is not used to endorse products
    00029       built using this software without specific written permission.
    00030
    00031  ALTERNATIVELY, provided that this notice is retained in full, this product
    00032  may be distributed under the terms of the GNU General Public License (GPL),
    00033  in which case the provisions of the GPL apply INSTEAD OF those given above.
    00034
    00035  DISCLAIMER
    00036
    00037  This software is provided 'as is' with no explicit or implied warranties
    00038  in respect of its properties, including, but not limited to, correctness
    00039  and/or fitness for purpose.
    00040  ---------------------------------------------------------------------------
    00041  Issue Date: 26/08/2003
    00042 */
    00043 /*!\file
    00044
    00045  \brief This file contains the definitions required to use AES in C. See aesopt.h
    00046  for optimisation details.
    00047 */
    00048
    00049 #ifndef _AES_H
    00050 #define _AES_H
    00051
    00052 /*  This include is used to find 8 & 32 bit unsigned integer types  */
    00053 #include "limits.h"
    00054
    00055 #if defined(__cplusplus)
    00056 extern "C"
    00057 {
    00058 #endif
    00059
    00060 #define AES_128     /* define if AES with 128 bit keys is needed    */
    00061 #undef AES_192     /* define if AES with 192 bit keys is needed    */
    00062 #undef AES_256     /* define if AES with 256 bit keys is needed    */
    00063 #undef AES_VAR     /* define if a variable key size is needed      */
    00064
    00065 /* The following must also be set in assembler files if being used  */
    00066
    00067 #define AES_ENCRYPT /* if support for encryption is needed          */
    00068 #define AES_DECRYPT /* if support for decryption is needed          */
    00069 #define AES_ERR_CHK /* for parameter checks & error return codes    */
    00070
    00071 #if UCHAR_MAX == 0xff                   /* an unsigned 8 bit type   */
    00072   typedef unsigned char      aes_08t;
    00073 #else
    00074 #error Please define aes_08t as an 8-bit unsigned integer type in aes.h
    00075 #endif
    00076
    00077 #if UINT_MAX == 0xffffffff              /* an unsigned 32 bit type  */
    00078   typedef   unsigned int     aes_32t;
    00079 #elif ULONG_MAX == 0xffffffff
    00080   typedef   unsigned long    aes_32t;
    00081 #else
    00082 #error Please define aes_32t as a 32-bit unsigned integer type in aes.h
    00083 #endif
    00084
    00085 #define AES_BLOCK_SIZE  16  /* the AES block size in bytes          */
    00086 #define N_COLS           4  /* the number of columns in the state   */
    00087
    00088 /* a maximum of 60 32-bit words are needed for the key schedule but */
    00089 /* 64 are claimed to allow space at the top for a CBC xor buffer.   */
    00090 /* If this is not needed, this value can be reduced to 60. A value  */
    00091 /* of 64 may also help in maintaining alignment in some situations  */
    00092 #define KS_LENGTH       64
    00093
    00094 #ifdef  AES_ERR_CHK
    00095 #define aes_ret     int
    00096 #define aes_good    0
    00097 #define aes_error  -1
    00098 #else
    00099 #define aes_ret     void
    00100 #endif
    00101
    00102 #ifndef AES_DLL                 /* implement normal/DLL functions   */
    00103 #define aes_rval    aes_ret
    00104 #else
    00105 #define aes_rval    aes_ret __declspec(dllexport) _stdcall
    00106 #endif
    00107
    00108 /* This routine must be called before first use if non-static       */
    00109 /* tables are being used                                            */
    00110
    00111 void gen_tabs(void);
    00112
    00113 /* The key length (klen) is input in bytes when it is in the range  */
    00114 /* 16 <= klen <= 32 or in bits when in the range 128 <= klen <= 256 */
    00115
    00116 #ifdef  AES_ENCRYPT
    00117
    00118 typedef struct
    00119 {   aes_32t ks[KS_LENGTH];
    00120 } aes_encrypt_ctx;
    00121
    00122 #if defined(AES_128) || defined(AES_VAR)
    00123 aes_rval aes_encrypt_key128(const void *in_key, aes_encrypt_ctx cx[1]);
    00124 #endif
    00125
    00126 #if defined(AES_192) || defined(AES_VAR)
    00127 aes_rval aes_encrypt_key192(const void *in_key, aes_encrypt_ctx cx[1]);
    00128 #endif
    00129
    00130 #if defined(AES_256) || defined(AES_VAR)
    00131 aes_rval aes_encrypt_key256(const void *in_key, aes_encrypt_ctx cx[1]);
    00132 #endif
    00133
    00134 #if defined(AES_VAR)
    00135 aes_rval aes_encrypt_key(const void *in_key, int key_len, aes_encrypt_ctx cx[1]);
    00136 #endif
    00137
    00138 aes_rval aes_encrypt(const void *in_blk, void *out_blk, const aes_encrypt_ctx cx[1]);
    00139 #endif
    00140
    00141 #ifdef AES_DECRYPT
    00142
    00143 typedef struct
    00144 {   aes_32t ks[KS_LENGTH];
    00145 } aes_decrypt_ctx;
    00146
    00147 #if defined(AES_128) || defined(AES_VAR)
    00148 aes_rval aes_decrypt_key128(const void *in_key, aes_decrypt_ctx cx[1]);
    00149 #endif
    00150
    00151 #if defined(AES_192) || defined(AES_VAR)
    00152 aes_rval aes_decrypt_key192(const void *in_key, aes_decrypt_ctx cx[1]);
    00153 #endif
    00154
    00155 #if defined(AES_256) || defined(AES_VAR)
    00156 aes_rval aes_decrypt_key256(const void *in_key, aes_decrypt_ctx cx[1]);
    00157 #endif
    00158
    00159 #if defined(AES_VAR)
    00160 aes_rval aes_decrypt_key(const void *in_key, int key_len, aes_decrypt_ctx cx[1]);
    00161 #endif
    00162
    00163 aes_rval aes_decrypt(const void *in_blk, void *out_blk, const aes_decrypt_ctx cx[1]);
    00164 #endif
    00165
    00166 #if defined(__cplusplus)
    00167 }
    00168 #endif
    00169
    00170 #endif