src/eap_peer/eap_md5.c

   1 /*
   2  * EAP peer method: EAP-MD5 (RFC 3748 and RFC 1994)
   3  * Copyright (c) 2004-2012, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "includes.h"
  10
  11 #include "common.h"
  12 #include "eap_i.h"
  13 #include "eap_common/chap.h"
  14
  15
  16 static void * eap_md5_init(struct eap_sm *sm)
  17 {
  18         /* No need for private data. However, must return non-NULL to indicate
  19          * success. */
  20         return (void *) 1;
  21 }
  22
  23
  24 static void eap_md5_deinit(struct eap_sm *sm, void *priv)
  25 {
  26 }
  27
  28
  29 static struct wpabuf * eap_md5_process(struct eap_sm *sm, void *priv,
  30                                        struct eap_method_ret *ret,
  31                                        const struct wpabuf *reqData)
  32 {
  33         struct wpabuf *resp;
  34         const u8 *pos, *challenge, *password;
  35         u8 *rpos, id;
  36         size_t len, challenge_len, password_len;
  37
  38         password = eap_get_config_password(sm, &password_len);
  39         if (password == NULL) {
  40                 wpa_printf(MSG_INFO, "EAP-MD5: Password not configured");
  41                 eap_sm_request_password(sm);
  42                 ret->ignore = TRUE;
  43                 return NULL;
  44         }
  45
  46         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5, reqData, &len);
  47         if (pos == NULL || len == 0) {
  48                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid frame (pos=%p len=%lu)",
  49                            pos, (unsigned long) len);
  50                 ret->ignore = TRUE;
  51                 return NULL;
  52         }
  53
  54         /*
  55          * CHAP Challenge:
  56          * Value-Size (1 octet) | Value(Challenge) | Name(optional)
  57          */
  58         challenge_len = *pos++;
  59         if (challenge_len == 0 || challenge_len > len - 1) {
  60                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid challenge "
  61                            "(challenge_len=%lu len=%lu)",
  62                            (unsigned long) challenge_len, (unsigned long) len);
  63                 ret->ignore = TRUE;
  64                 return NULL;
  65         }
  66         ret->ignore = FALSE;
  67         challenge = pos;
  68         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Challenge",
  69                     challenge, challenge_len);
  70
  71         wpa_printf(MSG_DEBUG, "EAP-MD5: Generating Challenge Response");
  72         ret->methodState = METHOD_DONE;
  73         ret->decision = DECISION_COND_SUCC;
  74         ret->allowNotifications = TRUE;
  75
  76         resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MD5, 1 + CHAP_MD5_LEN,
  77                              EAP_CODE_RESPONSE, eap_get_id(reqData));
  78         if (resp == NULL)
  79                 return NULL;
  80
  81         /*
  82          * CHAP Response:
  83          * Value-Size (1 octet) | Value(Response) | Name(optional)
  84          */
  85         wpabuf_put_u8(resp, CHAP_MD5_LEN);
  86
  87         id = eap_get_id(resp);
  88         rpos = wpabuf_put(resp, CHAP_MD5_LEN);
  89         if (chap_md5(id, password, password_len, challenge, challenge_len,
  90                      rpos)) {
  91                 wpa_printf(MSG_INFO, "EAP-MD5: CHAP MD5 operation failed");
  92                 ret->ignore = TRUE;
  93                 wpabuf_free(resp);
  94                 return NULL;
  95         }
  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
 106         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 107                                     EAP_VENDOR_IETF, EAP_TYPE_MD5, "MD5");
 108         if (eap == NULL)
 109                 return -1;
 110
 111         eap->init = eap_md5_init;
 112         eap->deinit = eap_md5_deinit;
 113         eap->process = eap_md5_process;
 114
 115         return eap_peer_method_register(eap);
 116 }