contrib/wpa_supplicant-0.5.8/eap_md5.c

   1 /*
   2  * EAP peer method: EAP-MD5 (RFC 3748 and RFC 1994)
   3  * Copyright (c) 2004-2006, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "eap_i.h"
  19 #include "md5.h"
  20 #include "crypto.h"
  21
  22
  23 static void * eap_md5_init(struct eap_sm *sm)
  24 {
  25         /* No need for private data. However, must return non-NULL to indicate
  26          * success. */
  27         return (void *) 1;
  28 }
  29
  30
  31 static void eap_md5_deinit(struct eap_sm *sm, void *priv)
  32 {
  33 }
  34
  35
  36 static u8 * eap_md5_process(struct eap_sm *sm, void *priv,
  37                             struct eap_method_ret *ret,
  38                             const u8 *reqData, size_t reqDataLen,
  39                             size_t *respDataLen)
  40 {
  41         const struct eap_hdr *req;
  42         struct eap_hdr *resp;
  43         const u8 *pos, *challenge, *password;
  44         u8 *rpos;
  45         size_t len, challenge_len, password_len;
  46         const u8 *addr[3];
  47         size_t elen[3];
  48
  49         password = eap_get_config_password(sm, &password_len);
  50         if (password == NULL) {
  51                 wpa_printf(MSG_INFO, "EAP-MD5: Password not configured");
  52                 eap_sm_request_password(sm);
  53                 ret->ignore = TRUE;
  54                 return NULL;
  55         }
  56
  57         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5,
  58                                reqData, reqDataLen, &len);
  59         if (pos == NULL || len == 0) {
  60                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid frame (pos=%p len=%lu)",
  61                            pos, (unsigned long) len);
  62                 ret->ignore = TRUE;
  63                 return NULL;
  64         }
  65
  66         /*
  67          * CHAP Challenge:
  68          * Value-Size (1 octet) | Value(Challenge) | Name(optional)
  69          */
  70         req = (const struct eap_hdr *) reqData;
  71         challenge_len = *pos++;
  72         if (challenge_len == 0 || challenge_len > len - 1) {
  73                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid challenge "
  74                            "(challenge_len=%lu len=%lu)",
  75                            (unsigned long) challenge_len, (unsigned long) len);
  76                 ret->ignore = TRUE;
  77                 return NULL;
  78         }
  79         ret->ignore = FALSE;
  80         challenge = pos;
  81         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Challenge",
  82                     challenge, challenge_len);
  83
  84         wpa_printf(MSG_DEBUG, "EAP-MD5: Generating Challenge Response");
  85         ret->methodState = METHOD_DONE;
  86         ret->decision = DECISION_UNCOND_SUCC;
  87         ret->allowNotifications = TRUE;
  88
  89         resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MD5, respDataLen,
  90                              1 + MD5_MAC_LEN, EAP_CODE_RESPONSE,
  91                              req->identifier, &rpos);
  92         if (resp == NULL)
  93                 return NULL;
  94
  95         /*
  96          * CHAP Response:
  97          * Value-Size (1 octet) | Value(Response) | Name(optional)
  98          */
  99         *rpos++ = MD5_MAC_LEN;
 100
 101         addr[0] = &resp->identifier;
 102         elen[0] = 1;
 103         addr[1] = password;
 104         elen[1] = password_len;
 105         addr[2] = challenge;
 106         elen[2] = challenge_len;
 107         md5_vector(3, addr, elen, rpos);
 108         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Response", rpos, MD5_MAC_LEN);
 109
 110         return (u8 *) resp;
 111 }
 112
 113
 114 int eap_peer_md5_register(void)
 115 {
 116         struct eap_method *eap;
 117         int ret;
 118
 119         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 120                                     EAP_VENDOR_IETF, EAP_TYPE_MD5, "MD5");
 121         if (eap == NULL)
 122                 return -1;
 123
 124         eap->init = eap_md5_init;
 125         eap->deinit = eap_md5_deinit;
 126         eap->process = eap_md5_process;
 127
 128         ret = eap_peer_method_register(eap);
 129         if (ret)
 130                 eap_peer_method_free(eap);
 131         return ret;
 132 }