src/eap_peer/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 "eap_common/chap.h"
  20
  21
  22 static void * eap_md5_init(struct eap_sm *sm)
  23 {
  24         /* No need for private data. However, must return non-NULL to indicate
  25          * success. */
  26         return (void *) 1;
  27 }
  28
  29
  30 static void eap_md5_deinit(struct eap_sm *sm, void *priv)
  31 {
  32 }
  33
  34
  35 static struct wpabuf * eap_md5_process(struct eap_sm *sm, void *priv,
  36                                        struct eap_method_ret *ret,
  37                                        const struct wpabuf *reqData)
  38 {
  39         struct wpabuf *resp;
  40         const u8 *pos, *challenge, *password;
  41         u8 *rpos, id;
  42         size_t len, challenge_len, password_len;
  43
  44         password = eap_get_config_password(sm, &password_len);
  45         if (password == NULL) {
  46                 wpa_printf(MSG_INFO, "EAP-MD5: Password not configured");
  47                 eap_sm_request_password(sm);
  48                 ret->ignore = TRUE;
  49                 return NULL;
  50         }
  51
  52         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5, reqData, &len);
  53         if (pos == NULL || len == 0) {
  54                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid frame (pos=%p len=%lu)",
  55                            pos, (unsigned long) len);
  56                 ret->ignore = TRUE;
  57                 return NULL;
  58         }
  59
  60         /*
  61          * CHAP Challenge:
  62          * Value-Size (1 octet) | Value(Challenge) | Name(optional)
  63          */
  64         challenge_len = *pos++;
  65         if (challenge_len == 0 || challenge_len > len - 1) {
  66                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid challenge "
  67                            "(challenge_len=%lu len=%lu)",
  68                            (unsigned long) challenge_len, (unsigned long) len);
  69                 ret->ignore = TRUE;
  70                 return NULL;
  71         }
  72         ret->ignore = FALSE;
  73         challenge = pos;
  74         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Challenge",
  75                     challenge, challenge_len);
  76
  77         wpa_printf(MSG_DEBUG, "EAP-MD5: Generating Challenge Response");
  78         ret->methodState = METHOD_DONE;
  79         ret->decision = DECISION_UNCOND_SUCC;
  80         ret->allowNotifications = TRUE;
  81
  82         resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MD5, 1 + CHAP_MD5_LEN,
  83                              EAP_CODE_RESPONSE, eap_get_id(reqData));
  84         if (resp == NULL)
  85                 return NULL;
  86
  87         /*
  88          * CHAP Response:
  89          * Value-Size (1 octet) | Value(Response) | Name(optional)
  90          */
  91         wpabuf_put_u8(resp, CHAP_MD5_LEN);
  92
  93         id = eap_get_id(resp);
  94         rpos = wpabuf_put(resp, CHAP_MD5_LEN);
  95         chap_md5(id, password, password_len, challenge, challenge_len, rpos);
  96         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Response", rpos, CHAP_MD5_LEN);
  97
  98         return resp;
  99 }
 100
 101
 102 int eap_peer_md5_register(void)
 103 {
 104         struct eap_method *eap;
 105         int ret;
 106
 107         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 108                                     EAP_VENDOR_IETF, EAP_TYPE_MD5, "MD5");
 109         if (eap == NULL)
 110                 return -1;
 111
 112         eap->init = eap_md5_init;
 113         eap->deinit = eap_md5_deinit;
 114         eap->process = eap_md5_process;
 115
 116         ret = eap_peer_method_register(eap);
 117         if (ret)
 118                 eap_peer_method_free(eap);
 119         return ret;
 120 }