src/libsimaka/simaka_message.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_message simaka_message
  18  * @{ @ingroup libsimaka
  19  */
  20
  21 #ifndef SIMAKA_MESSAGE_H_
  22 #define SIMAKA_MESSAGE_H_
  23
  24 #include <enum.h>
  25 #include <daemon.h>
  26
  27 #include "simaka_crypto.h"
  28
  29 typedef struct simaka_message_t simaka_message_t;
  30 typedef enum simaka_attribute_t simaka_attribute_t;
  31 typedef enum simaka_subtype_t simaka_subtype_t;
  32
  33 /**
  34  * Subtypes of EAP-SIM/AKA messages
  35  */
  36 enum simaka_subtype_t {
  37         AKA_CHALLENGE = 1,
  38         AKA_AUTHENTICATION_REJECT = 2,
  39         AKA_SYNCHRONIZATION_FAILURE = 4,
  40         AKA_IDENTITY = 5,
  41         SIM_START = 10,
  42         SIM_CHALLENGE = 11,
  43         SIM_NOTIFICATION = 12,
  44         AKA_NOTIFICATION = 12,
  45         SIM_REAUTHENTICATION = 13,
  46         AKA_REAUTHENTICATION = 13,
  47         SIM_CLIENT_ERROR = 14,
  48         AKA_CLIENT_ERROR = 14,
  49 };
  50
  51 /**
  52  * Enum names for simaka_subtype_t
  53  */
  54 extern enum_name_t *simaka_subtype_names;
  55
  56 /**
  57  * Attributes in EAP-SIM/AKA messages
  58  */
  59 enum simaka_attribute_t {
  60         AT_RAND = 1,
  61         AT_AUTN = 2,
  62         AT_RES = 3,
  63         AT_AUTS = 4,
  64         AT_PADDING = 6,
  65         AT_NONCE_MT = 7,
  66         AT_PERMANENT_ID_REQ = 10,
  67         AT_MAC = 11,
  68         AT_NOTIFICATION = 12,
  69         AT_ANY_ID_REQ = 13,
  70         AT_IDENTITY = 14,
  71         AT_VERSION_LIST = 15,
  72         AT_SELECTED_VERSION = 16,
  73         AT_FULLAUTH_ID_REQ = 17,
  74         AT_COUNTER = 19,
  75         AT_COUNTER_TOO_SMALL = 20,
  76         AT_NONCE_S = 21,
  77         AT_CLIENT_ERROR_CODE = 22,
  78         AT_IV = 129,
  79         AT_ENCR_DATA = 130,
  80         AT_NEXT_PSEUDONYM = 132,
  81         AT_NEXT_REAUTH_ID = 133,
  82         AT_CHECKCODE = 134,
  83         AT_RESULT_IND = 135,
  84 };
  85
  86 /**
  87  * Enum names for simaka_attribute_t
  88  */
  89 extern enum_name_t *simaka_attribute_names;
  90
  91 /**
  92  * EAP-SIM and EAP-AKA message abstraction.
  93  *
  94  * Messages for EAP-SIM and EAP-AKA share a common format, this class
  95  * abstracts such a message and provides encoding/encryption/signing
  96  * functionality.
  97  */
  98 struct simaka_message_t {
  99
 100         /**
 101          * Check if the given message is a request or response.
 102          *
 103          * @return                      TRUE if request, FALSE if response
 104          */
 105         bool (*is_request)(simaka_message_t *this);
 106
 107         /**
 108          * Get the EAP message identifier.
 109          *
 110          * @return                      EAP message identifier
 111          */
 112         u_int8_t (*get_identifier)(simaka_message_t *this);
 113
 114         /**
 115          * Get the EAP type of the message.
 116          *
 117          * @return                      EAP type: EAP-SIM or EAP-AKA
 118          */
 119         eap_type_t (*get_type)(simaka_message_t *this);
 120
 121         /**
 122          * Get the subtype of an EAP-SIM message.
 123          *
 124          * @return                      subtype of message
 125          */
 126         simaka_subtype_t (*get_subtype)(simaka_message_t *this);
 127
 128         /**
 129          * Create an enumerator over message attributes.
 130          *
 131          * @return                      enumerator over (simaka_attribute_t, chunk_t)
 132          */
 133         enumerator_t* (*create_attribute_enumerator)(simaka_message_t *this);
 134
 135         /**
 136          * Append an attribute to the EAP-SIM message.
 137          *
 138          * Make sure to pass only data of correct length for the given attribute.
 139          *
 140          * @param type          type of attribute to add to message
 141          * @param data          unpadded attribute data to add
 142          */
 143         void (*add_attribute)(simaka_message_t *this, simaka_attribute_t type,
 144                                                   chunk_t data);
 145
 146         /**
 147          * Parse a message, with optional attribute decryption.
 148          *
 149          * This method does not verify message integrity, as the key is available
 150          * only after the payload has been parsed.
 151          *
 152          * @param crypto        EAP-SIM/AKA crypto helper
 153          * @return                      TRUE if message parsed successfully
 154          */
 155         bool (*parse)(simaka_message_t *this, simaka_crypto_t *crypto);
 156
 157         /**
 158          * Verify the message integrity of a parsed message.
 159          *
 160          * @param crypto        EAP-SIM/AKA crypto helper
 161          * @param sigdata       additional data to include in signature, if any
 162          * @return                      TRUE if message integrity check successful
 163          */
 164         bool (*verify)(simaka_message_t *this, simaka_crypto_t *crypto,
 165                                    chunk_t sigdata);
 166
 167         /**
 168          * Generate a message, optionally encrypt attributes and create a MAC.
 169          *
 170          * @param crypto        EAP-SIM/AKA crypto helper
 171          * @param sigdata       additional data to include in signature, if any
 172          * @return                      generated eap payload, NULL if failed
 173          */
 174         eap_payload_t* (*generate)(simaka_message_t *this, simaka_crypto_t *crypto,
 175                                                            chunk_t sigdata);
 176
 177         /**
 178          * Destroy a simaka_message_t.
 179          */
 180         void (*destroy)(simaka_message_t *this);
 181 };
 182
 183 /**
 184  * Create an empty simaka_message.
 185  *
 186  * @param request               TRUE for a request message, FALSE for a response
 187  * @param identifier    EAP message identifier
 188  * @param type                  EAP subtype of the message
 189  * @return                              empty message of requested kind, NULL on error
 190  */
 191 simaka_message_t *simaka_message_create(bool request, u_int8_t identifier,
 192                                                                 eap_type_t type, simaka_subtype_t subtype);
 193
 194 /**
 195  * Create an simaka_message from a chunk of data.
 196  *
 197  * @param payload               payload to create message from
 198  * @return                              EAP message, NULL on error
 199  */
 200 simaka_message_t *simaka_message_create_from_payload(eap_payload_t *payload);
 201
 202 #endif /* SIMAKA_MESSAGE_H_ @}*/