src/libstrongswan/crypto/hashers/hasher.h

   1 /*
   2  * Copyright (C) 2005 Jan Hutter
   3  * Copyright (C) 2005-2006 Martin Willi
   4  *
   5  * Hochschule fuer Technik Rapperswil
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2 of the License, or (at your
  10  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  * for more details.
  16  */
  17
  18 /**
  19  * @defgroup hasher hasher
  20  * @{ @ingroup crypto
  21  */
  22
  23 #ifndef HASHER_H_
  24 #define HASHER_H_
  25
  26 typedef enum hash_algorithm_t hash_algorithm_t;
  27 typedef struct hasher_t hasher_t;
  28
  29 #include <library.h>
  30 #include <credentials/keys/public_key.h>
  31
  32 /**
  33  * Algorithms to use for hashing.
  34  */
  35 enum hash_algorithm_t {
  36         /** not specified hash function */
  37         HASH_UNKNOWN            = 0,
  38         /** preferred hash function, general purpose */
  39         HASH_PREFERRED          = 1,
  40         HASH_MD2                        = 2,
  41         HASH_MD4                        = 3,
  42         HASH_MD5                        = 4,
  43         HASH_SHA1                       = 5,
  44         HASH_SHA224                     = 6,
  45         HASH_SHA256             = 7,
  46         HASH_SHA384             = 8,
  47         HASH_SHA512             = 9
  48 };
  49
  50 #define HASH_SIZE_MD2           16
  51 #define HASH_SIZE_MD4           16
  52 #define HASH_SIZE_MD5           16
  53 #define HASH_SIZE_SHA1          20
  54 #define HASH_SIZE_SHA224        28
  55 #define HASH_SIZE_SHA256        32
  56 #define HASH_SIZE_SHA384        48
  57 #define HASH_SIZE_SHA512        64
  58
  59 /**
  60  * enum names for hash_algorithm_t.
  61  */
  62 extern enum_name_t *hash_algorithm_names;
  63
  64 /**
  65  * Generic interface for all hash functions.
  66  */
  67 struct hasher_t {
  68         /**
  69          * Hash data and write it in the buffer.
  70          *
  71          * If the parameter hash is NULL, no result is written back
  72          * and more data can be appended to already hashed data.
  73          * If not, the result is written back and the hasher is reset.
  74          *
  75          * The hash output parameter must hold at least
  76          * hash_t.get_block_size() bytes.
  77          *
  78          * @param data          data to hash
  79          * @param hash          pointer where the hash will be written
  80          */
  81         void (*get_hash) (hasher_t *this, chunk_t data, u_int8_t *hash);
  82
  83         /**
  84          * Hash data and allocate space for the hash.
  85          *
  86          * If the parameter hash is NULL, no result is written back
  87          * and more data can be appended to already hashed data.
  88          * If not, the result is written back and the hasher is reset.
  89          *
  90          * @param data          chunk with data to hash
  91          * @param hash          chunk which will hold allocated hash
  92          */
  93         void (*allocate_hash) (hasher_t *this, chunk_t data, chunk_t *hash);
  94
  95         /**
  96          * Get the size of the resulting hash.
  97          *
  98          * @return                      hash size in bytes
  99          */
 100         size_t (*get_hash_size) (hasher_t *this);
 101
 102         /**
 103          * Resets the hashers state.
 104          */
 105         void (*reset) (hasher_t *this);
 106
 107         /**
 108          * Destroys a hasher object.
 109          */
 110         void (*destroy) (hasher_t *this);
 111 };
 112
 113 /**
 114  * Conversion of ASN.1 OID to hash algorithm.
 115  *
 116  * @param oid                   ASN.1 OID
 117  * @return                              hash algorithm, HASH_UNKNOWN if OID unsuported
 118  */
 119 hash_algorithm_t hasher_algorithm_from_oid(int oid);
 120
 121 /**
 122  * Conversion of hash algorithm into ASN.1 OID.
 123  *
 124  * @param alg                   hash algorithm
 125  * @return                              ASN.1 OID, or OID_UNKNOW
 126  */
 127 int hasher_algorithm_to_oid(hash_algorithm_t alg);
 128
 129 /**
 130  * Conversion of hash signature algorithm into ASN.1 OID.
 131  *
 132  * @param alg                   hash algorithm
 133  * @param alg                   public key type
 134  * @return                              ASN.1 OID if, or OID_UNKNOW
 135  */
 136 int hasher_signature_algorithm_to_oid(hash_algorithm_t alg, key_type_t key);
 137
 138 #endif /** HASHER_H_ @}*/