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
16static 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
24static void eap_md5_deinit(struct eap_sm *sm, void *priv)
25{
26}
27
28
29static 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
102int 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}
121