1 /*
2 * hostapd / EAP-MD5 server
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 "crypto/random.h"
13 #include "eap_i.h"
14 #include "eap_common/chap.h"
15
16
17 #define CHALLENGE_LEN 16
18
19 struct eap_md5_data {
20 u8 challenge[CHALLENGE_LEN];
21 enum { CONTINUE, SUCCESS, FAILURE } state;
22 };
23
24
eap_md5_init(struct eap_sm * sm)25 static void * eap_md5_init(struct eap_sm *sm)
26 {
27 struct eap_md5_data *data;
28
29 data = os_zalloc(sizeof(*data));
30 if (data == NULL)
31 return NULL;
32 data->state = CONTINUE;
33
34 return data;
35 }
36
37
eap_md5_reset(struct eap_sm * sm,void * priv)38 static void eap_md5_reset(struct eap_sm *sm, void *priv)
39 {
40 struct eap_md5_data *data = priv;
41 os_free(data);
42 }
43
44
eap_md5_buildReq(struct eap_sm * sm,void * priv,u8 id)45 static struct wpabuf * eap_md5_buildReq(struct eap_sm *sm, void *priv, u8 id)
46 {
47 struct eap_md5_data *data = priv;
48 struct wpabuf *req;
49
50 if (random_get_bytes(data->challenge, CHALLENGE_LEN)) {
51 wpa_printf(MSG_ERROR, "EAP-MD5: Failed to get random data");
52 data->state = FAILURE;
53 return NULL;
54 }
55
56 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MD5, 1 + CHALLENGE_LEN,
57 EAP_CODE_REQUEST, id);
58 if (req == NULL) {
59 wpa_printf(MSG_ERROR, "EAP-MD5: Failed to allocate memory for "
60 "request");
61 data->state = FAILURE;
62 return NULL;
63 }
64
65 wpabuf_put_u8(req, CHALLENGE_LEN);
66 wpabuf_put_data(req, data->challenge, CHALLENGE_LEN);
67 wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Challenge", data->challenge,
68 CHALLENGE_LEN);
69
70 data->state = CONTINUE;
71
72 return req;
73 }
74
75
eap_md5_check(struct eap_sm * sm,void * priv,struct wpabuf * respData)76 static Boolean eap_md5_check(struct eap_sm *sm, void *priv,
77 struct wpabuf *respData)
78 {
79 const u8 *pos;
80 size_t len;
81
82 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5, respData, &len);
83 if (pos == NULL || len < 1) {
84 wpa_printf(MSG_INFO, "EAP-MD5: Invalid frame");
85 return TRUE;
86 }
87 if (*pos != CHAP_MD5_LEN || 1 + CHAP_MD5_LEN > len) {
88 wpa_printf(MSG_INFO, "EAP-MD5: Invalid response "
89 "(response_len=%d payload_len=%lu",
90 *pos, (unsigned long) len);
91 return TRUE;
92 }
93
94 return FALSE;
95 }
96
97
eap_md5_process(struct eap_sm * sm,void * priv,struct wpabuf * respData)98 static void eap_md5_process(struct eap_sm *sm, void *priv,
99 struct wpabuf *respData)
100 {
101 struct eap_md5_data *data = priv;
102 const u8 *pos;
103 size_t plen;
104 u8 hash[CHAP_MD5_LEN], id;
105
106 if (sm->user == NULL || sm->user->password == NULL ||
107 sm->user->password_hash) {
108 wpa_printf(MSG_INFO, "EAP-MD5: Plaintext password not "
109 "configured");
110 data->state = FAILURE;
111 return;
112 }
113
114 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5, respData, &plen);
115 if (pos == NULL || *pos != CHAP_MD5_LEN || plen < 1 + CHAP_MD5_LEN)
116 return; /* Should not happen - frame already validated */
117
118 pos++; /* Skip response len */
119 wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Response", pos, CHAP_MD5_LEN);
120
121 id = eap_get_id(respData);
122 if (chap_md5(id, sm->user->password, sm->user->password_len,
123 data->challenge, CHALLENGE_LEN, hash)) {
124 wpa_printf(MSG_INFO, "EAP-MD5: CHAP MD5 operation failed");
125 data->state = FAILURE;
126 return;
127 }
128
129 if (os_memcmp_const(hash, pos, CHAP_MD5_LEN) == 0) {
130 wpa_printf(MSG_DEBUG, "EAP-MD5: Done - Success");
131 data->state = SUCCESS;
132 } else {
133 wpa_printf(MSG_DEBUG, "EAP-MD5: Done - Failure");
134 data->state = FAILURE;
135 }
136 }
137
138
eap_md5_isDone(struct eap_sm * sm,void * priv)139 static Boolean eap_md5_isDone(struct eap_sm *sm, void *priv)
140 {
141 struct eap_md5_data *data = priv;
142 return data->state != CONTINUE;
143 }
144
145
eap_md5_isSuccess(struct eap_sm * sm,void * priv)146 static Boolean eap_md5_isSuccess(struct eap_sm *sm, void *priv)
147 {
148 struct eap_md5_data *data = priv;
149 return data->state == SUCCESS;
150 }
151
152
eap_server_md5_register(void)153 int eap_server_md5_register(void)
154 {
155 struct eap_method *eap;
156 int ret;
157
158 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
159 EAP_VENDOR_IETF, EAP_TYPE_MD5, "MD5");
160 if (eap == NULL)
161 return -1;
162
163 eap->init = eap_md5_init;
164 eap->reset = eap_md5_reset;
165 eap->buildReq = eap_md5_buildReq;
166 eap->check = eap_md5_check;
167 eap->process = eap_md5_process;
168 eap->isDone = eap_md5_isDone;
169 eap->isSuccess = eap_md5_isSuccess;
170
171 ret = eap_server_method_register(eap);
172 if (ret)
173 eap_server_method_free(eap);
174 return ret;
175 }
176