src/libsimaka/simaka_crypto.h

   1 /*
   2  * Copyright (C) 2009 Martin Willi
   3  * Hochschule fuer Technik Rapperswil
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  */
  15
  16 /**
  17  * @defgroup simaka_crypto simaka_crypto
  18  * @{ @ingroup libsimaka
  19  */
  20
  21 #ifndef SIMAKA_CRYPTO_H_
  22 #define SIMAKA_CRYPTO_H_
  23
  24 #include <library.h>
  25
  26 typedef struct simaka_crypto_t simaka_crypto_t;
  27
  28 /**
  29  * EAP-SIM/AKA crypto helper and key derivation class.
  30  */
  31 struct simaka_crypto_t {
  32
  33         /**
  34          * Get the signer to use for AT_MAC calculation/verification.
  35          *
  36          * @return              signer reference, NULL if no keys have been derived
  37          */
  38         signer_t* (*get_signer)(simaka_crypto_t *this);
  39
  40         /**
  41          * Get the signer to use for AT_ENCR_DATA encryption/decryption.
  42          *
  43          * @return              crypter reference, NULL if no keys have been derived
  44          */
  45         crypter_t* (*get_crypter)(simaka_crypto_t *this);
  46
  47         /**
  48          * Get the random number generator.
  49          *
  50          * @return              rng reference
  51          */
  52         rng_t* (*get_rng)(simaka_crypto_t *this);
  53
  54         /**
  55          * Derive keys after full authentication.
  56          *
  57          * This methods derives the k_encr/k_auth keys and loads them into the
  58          * internal crypter/signer instances. The passed data is method specific:
  59          * For EAP-SIM, it is "n*Kc|NONCE_MT|Version List|Selected Version", for
  60          * EAP-AKA it is "IK|CK".
  61          *
  62          * @param id    peer identity
  63          * @param data  method specific data
  64          * @param mk    chunk receiving allocated master key MK
  65          * @return              allocated MSK value
  66          */
  67         chunk_t (*derive_keys_full)(simaka_crypto_t *this, identification_t *id,
  68                                                                 chunk_t data, chunk_t *mk);
  69
  70         /**
  71          * Derive k_encr/k_auth keys from MK using fast reauthentication.
  72          *
  73          * This methods derives the k_encr/k_auth keys and loads them into the
  74          * internal crypter/signer instances.
  75          *
  76          * @param mk    master key
  77          */
  78         void (*derive_keys_reauth)(simaka_crypto_t *this, chunk_t mk);
  79
  80         /**
  81          * Derive MSK using fast reauthentication.
  82          *
  83          * @param id            fast reauthentication identity
  84          * @param counter       fast reauthentication counter value, network order
  85          * @param nonce_s       server generated NONCE_S value
  86          * @param mk            master key of last full authentication
  87          */
  88         chunk_t (*derive_keys_reauth_msk)(simaka_crypto_t *this,
  89                                                                           identification_t *id, chunk_t counter,
  90                                                                           chunk_t nonce_s, chunk_t mk);
  91
  92         /**
  93          * Clear keys (partially) derived.
  94          */
  95         void (*clear_keys)(simaka_crypto_t *this);
  96
  97         /**
  98          * Destroy a simaka_crypto_t.
  99          */
 100         void (*destroy)(simaka_crypto_t *this);
 101 };
 102
 103 /**
 104  * Create a simaka_crypto instance.
 105  *
 106  * @return              EAP-SIM/AKA crypto instance, NULL if algorithms missing
 107  */
 108 simaka_crypto_t *simaka_crypto_create();
 109
 110 #endif /** SIMAKA_CRYPTO_H_ @}*/