programs/charon/lib/crypto/crypters/crypter.h

   1 /**
   2  * @file crypter.h
   3  *
   4  * @brief Interface crypter_t
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2005 Jan Hutter, Martin Willi
  10  * Hochschule fuer Technik Rapperswil
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the
  14  * Free Software Foundation; either version 2 of the License, or (at your
  15  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  */
  22
  23 #ifndef CRYPTER_H_
  24 #define CRYPTER_H_
  25
  26 #include <types.h>
  27
  28 typedef enum encryption_algorithm_t encryption_algorithm_t;
  29
  30 /**
  31  * @brief Encryption algorithm, as in IKEv2 RFC 3.3.2.
  32  *
  33  * Currently only the following algorithms are implemented and therefore supported:
  34  * - ENCR_AES_CBC
  35  *
  36  * @todo Implement more enryption algorithms, such as 3DES
  37  *
  38  * @ingroup crypters
  39  */
  40 enum encryption_algorithm_t {
  41         ENCR_UNDEFINED = 1024,
  42         ENCR_DES_IV64 = 1,
  43         ENCR_DES = 2,
  44         ENCR_3DES = 3,
  45         ENCR_RC5 = 4,
  46         ENCR_IDEA = 5,
  47         ENCR_CAST = 6,
  48         ENCR_BLOWFISH = 7,
  49         ENCR_3IDEA = 8,
  50         ENCR_DES_IV32 = 9,
  51         ENCR_NULL = 11,
  52         /**
  53          * Implemented in class aes_cbc_crypter_t.
  54          */
  55         ENCR_AES_CBC = 12,
  56         ENCR_AES_CTR = 13
  57 };
  58
  59 /**
  60  * String mappings for encryption_algorithm_t.
  61  */
  62 extern mapping_t encryption_algorithm_m[];
  63
  64
  65 typedef struct crypter_t crypter_t;
  66
  67 /**
  68  * @brief Generic interface for symmetric encryption algorithms.
  69  *
  70  * @b Constructors:
  71  *  - crypter_create()
  72  *
  73  * @ingroup crypters
  74  */
  75 struct crypter_t {
  76         /**
  77          * @brief Encrypt a chunk of data and allocate space for the encrypted value.
  78          *
  79          * @param this                          calling object
  80          * @param data                          data to encrypt
  81          * @param iv                            initializing vector
  82          * @param[out] encrypted        pointer where the encrypted bytes will be written
  83          * @return
  84          *                                                      - SUCCESS
  85          *                                                      - INVALID_ARG if data size not a multiple of block size
  86          */
  87         status_t (*encrypt) (crypter_t *this, chunk_t data, chunk_t iv, chunk_t *encrypted);
  88
  89         /**
  90          * @brief Decrypt a chunk of data and allocate space for the decrypted value.
  91          *
  92          * @param this                          calling object
  93          * @param data                          data to decrypt
  94          * @param iv                            initializing vector
  95          * @param[out] encrypted        pointer where the decrypted bytes will be written
  96          * @return
  97          *                                                      - SUCCESS
  98          *                                                      - INVALID_ARG if data size not a multiple of block size
  99          */
 100         status_t (*decrypt) (crypter_t *this, chunk_t data, chunk_t iv, chunk_t *decrypted);
 101
 102         /**
 103          * @brief Get the block size of this crypter_t object.
 104          *
 105          * @param this                          calling object
 106          * @return                                      block size in bytes
 107          */
 108         size_t (*get_block_size) (crypter_t *this);
 109
 110         /**
 111          * @brief Get the key size of this crypter_t object.
 112          *
 113          * @param this                          calling object
 114          * @return                                      key size in bytes
 115          */
 116         size_t (*get_key_size) (crypter_t *this);
 117
 118         /**
 119          * @brief Set the key for this crypter_t object.
 120          *
 121          * @param this                          calling object
 122          * @param key                           key to set
 123          * @return
 124          *                                                      - SUCCESS
 125          *                                                      - INVALID_ARG if key length invalid
 126          */
 127         status_t (*set_key) (crypter_t *this, chunk_t key);
 128
 129         /**
 130          * @brief Destroys a crypter_t object.
 131          *
 132          * @param this                          calling object
 133          */
 134         void (*destroy) (crypter_t *this);
 135 };
 136
 137 /**
 138  * @brief Generic constructor for crypter_t objects.
 139  *
 140  * Currently only the following algorithms are implemented and therefore supported:
 141  * - ENCR_AES_CBC
 142  *
 143  * The key_size is ignored for algorithms with fixed key size.
 144  *
 145  * @param encryption_algorithm  Algorithm to use for crypter
 146  * @param key_size                              size of the key in bytes
 147  * @return
 148  *                                                              - crypter_t object
 149  *                                                              - NULL if encryption algorithm/key_size is not supported
 150  */
 151 crypter_t *crypter_create(encryption_algorithm_t encryption_algorithm, size_t key_size);
 152
 153 #endif /*CRYPTER_H_*/