eap_server_md5.c revision c5ec7f57ead87efa365800228aa0b09a12d9e6c4 
1/*
2 * hostapd / EAP-MD5 server
3 * Copyright (c) 2004-2007, 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
19struct eap_md5_data {
20	u8 challenge[CHALLENGE_LEN];
21	enum { CONTINUE, SUCCESS, FAILURE } state;
22};
23
24
25static 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
38static 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
45static 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
76static 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
98static 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	chap_md5(id, sm->user->password, sm->user->password_len,
123		 data->challenge, CHALLENGE_LEN, hash);
124
125	if (os_memcmp(hash, pos, CHAP_MD5_LEN) == 0) {
126		wpa_printf(MSG_DEBUG, "EAP-MD5: Done - Success");
127		data->state = SUCCESS;
128	} else {
129		wpa_printf(MSG_DEBUG, "EAP-MD5: Done - Failure");
130		data->state = FAILURE;
131	}
132}
133
134
135static Boolean eap_md5_isDone(struct eap_sm *sm, void *priv)
136{
137	struct eap_md5_data *data = priv;
138	return data->state != CONTINUE;
139}
140
141
142static Boolean eap_md5_isSuccess(struct eap_sm *sm, void *priv)
143{
144	struct eap_md5_data *data = priv;
145	return data->state == SUCCESS;
146}
147
148
149int eap_server_md5_register(void)
150{
151	struct eap_method *eap;
152	int ret;
153
154	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
155				      EAP_VENDOR_IETF, EAP_TYPE_MD5, "MD5");
156	if (eap == NULL)
157		return -1;
158
159	eap->init = eap_md5_init;
160	eap->reset = eap_md5_reset;
161	eap->buildReq = eap_md5_buildReq;
162	eap->check = eap_md5_check;
163	eap->process = eap_md5_process;
164	eap->isDone = eap_md5_isDone;
165	eap->isSuccess = eap_md5_isSuccess;
166
167	ret = eap_server_method_register(eap);
168	if (ret)
169		eap_server_method_free(eap);
170	return ret;
171}
172