1 /*
2 * EAP peer method: EAP-TLV (draft-josefsson-pppext-eap-tls-eap-07.txt)
3 * Copyright (c) 2004-2008, 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_tlv.h"
20
21
22 /**
23 * eap_tlv_build_nak - Build EAP-TLV NAK message
24 * @id: EAP identifier for the header
25 * @nak_type: TLV type (EAP_TLV_*)
26 * @resp_len: Buffer for returning the response length
27 * Returns: Buffer to the allocated EAP-TLV NAK message or %NULL on failure
28 *
29 * This funtion builds an EAP-TLV NAK message. The caller is responsible for
30 * freeing the returned buffer.
31 */
eap_tlv_build_nak(int id,u16 nak_type,size_t * resp_len)32 u8 * eap_tlv_build_nak(int id, u16 nak_type, size_t *resp_len)
33 {
34 struct eap_hdr *hdr;
35 u8 *pos;
36
37 hdr = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TLV, resp_len,
38 10, EAP_CODE_RESPONSE, id, &pos);
39 if (hdr == NULL)
40 return NULL;
41
42 *pos++ = 0x80; /* Mandatory */
43 *pos++ = EAP_TLV_NAK_TLV;
44 /* Length */
45 *pos++ = 0;
46 *pos++ = 6;
47 /* Vendor-Id */
48 *pos++ = 0;
49 *pos++ = 0;
50 *pos++ = 0;
51 *pos++ = 0;
52 /* NAK-Type */
53 WPA_PUT_BE16(pos, nak_type);
54
55 return (u8 *) hdr;
56 }
57
58
59 /**
60 * eap_tlv_build_result - Build EAP-TLV Result message
61 * @id: EAP identifier for the header
62 * @status: Status (EAP_TLV_RESULT_SUCCESS or EAP_TLV_RESULT_FAILURE)
63 * @resp_len: Buffer for returning the response length
64 * Returns: Buffer to the allocated EAP-TLV Result message or %NULL on failure
65 *
66 * This funtion builds an EAP-TLV Result message. The caller is responsible for
67 * freeing the returned buffer.
68 */
eap_tlv_build_result(int id,u16 status,size_t * resp_len)69 u8 * eap_tlv_build_result(int id, u16 status, size_t *resp_len)
70 {
71 struct eap_hdr *hdr;
72 u8 *pos;
73
74 hdr = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TLV, resp_len,
75 6, EAP_CODE_RESPONSE, id, &pos);
76 if (hdr == NULL)
77 return NULL;
78
79 *pos++ = 0x80; /* Mandatory */
80 *pos++ = EAP_TLV_RESULT_TLV;
81 /* Length */
82 *pos++ = 0;
83 *pos++ = 2;
84 /* Status */
85 WPA_PUT_BE16(pos, status);
86
87 return (u8 *) hdr;
88 }
89
90
91 /**
92 * eap_tlv_process - Process a received EAP-TLV message and generate a response
93 * @sm: Pointer to EAP state machine allocated with eap_sm_init()
94 * @ret: Return values from EAP request validation and processing
95 * @hdr: EAP-TLV request to be processed. The caller must have validated that
96 * the buffer is large enough to contain full request (hdr->length bytes) and
97 * that the EAP type is EAP_TYPE_TLV.
98 * @resp: Buffer to return a pointer to the allocated response message. This
99 * field should be initialized to %NULL before the call. The value will be
100 * updated if a response message is generated. The caller is responsible for
101 * freeing the allocated message.
102 * @resp_len: Buffer for returning the response length
103 * Returns: 0 on success, -1 on failure
104 */
eap_tlv_process(struct eap_sm * sm,struct eap_method_ret * ret,const struct eap_hdr * hdr,u8 ** resp,size_t * resp_len,int force_failure)105 int eap_tlv_process(struct eap_sm *sm, struct eap_method_ret *ret,
106 const struct eap_hdr *hdr, u8 **resp, size_t *resp_len,
107 int force_failure)
108 {
109 size_t left, tlv_len;
110 const u8 *pos;
111 const u8 *result_tlv = NULL;
112 size_t result_tlv_len = 0;
113 int tlv_type, mandatory;
114
115 /* Parse TLVs */
116 left = be_to_host16(hdr->length) - sizeof(struct eap_hdr) - 1;
117 pos = (const u8 *) (hdr + 1);
118 pos++;
119 wpa_hexdump(MSG_DEBUG, "EAP-TLV: Received TLVs", pos, left);
120 while (left >= 4) {
121 mandatory = !!(pos[0] & 0x80);
122 tlv_type = WPA_GET_BE16(pos) & 0x3fff;
123 pos += 2;
124 tlv_len = WPA_GET_BE16(pos);
125 pos += 2;
126 left -= 4;
127 if (tlv_len > left) {
128 wpa_printf(MSG_DEBUG, "EAP-TLV: TLV underrun "
129 "(tlv_len=%lu left=%lu)",
130 (unsigned long) tlv_len,
131 (unsigned long) left);
132 return -1;
133 }
134 switch (tlv_type) {
135 case EAP_TLV_RESULT_TLV:
136 result_tlv = pos;
137 result_tlv_len = tlv_len;
138 break;
139 default:
140 wpa_printf(MSG_DEBUG, "EAP-TLV: Unsupported TLV Type "
141 "%d%s", tlv_type,
142 mandatory ? " (mandatory)" : "");
143 if (mandatory) {
144 /* NAK TLV and ignore all TLVs in this packet.
145 */
146 *resp = eap_tlv_build_nak(hdr->identifier,
147 tlv_type, resp_len);
148 return *resp == NULL ? -1 : 0;
149 }
150 /* Ignore this TLV, but process other TLVs */
151 break;
152 }
153
154 pos += tlv_len;
155 left -= tlv_len;
156 }
157 if (left) {
158 wpa_printf(MSG_DEBUG, "EAP-TLV: Last TLV too short in "
159 "Request (left=%lu)", (unsigned long) left);
160 return -1;
161 }
162
163 /* Process supported TLVs */
164 if (result_tlv) {
165 int status, resp_status;
166 wpa_hexdump(MSG_DEBUG, "EAP-TLV: Result TLV",
167 result_tlv, result_tlv_len);
168 if (result_tlv_len < 2) {
169 wpa_printf(MSG_INFO, "EAP-TLV: Too short Result TLV "
170 "(len=%lu)",
171 (unsigned long) result_tlv_len);
172 return -1;
173 }
174 status = WPA_GET_BE16(result_tlv);
175 if (status == EAP_TLV_RESULT_SUCCESS) {
176 wpa_printf(MSG_INFO, "EAP-TLV: TLV Result - Success "
177 "- EAP-TLV/Phase2 Completed");
178 if (force_failure) {
179 wpa_printf(MSG_INFO, "EAP-TLV: Earlier failure"
180 " - force failed Phase 2");
181 resp_status = EAP_TLV_RESULT_FAILURE;
182 ret->decision = DECISION_FAIL;
183 } else {
184 resp_status = EAP_TLV_RESULT_SUCCESS;
185 ret->decision = DECISION_UNCOND_SUCC;
186 }
187 } else if (status == EAP_TLV_RESULT_FAILURE) {
188 wpa_printf(MSG_INFO, "EAP-TLV: TLV Result - Failure");
189 resp_status = EAP_TLV_RESULT_FAILURE;
190 ret->decision = DECISION_FAIL;
191 } else {
192 wpa_printf(MSG_INFO, "EAP-TLV: Unknown TLV Result "
193 "Status %d", status);
194 resp_status = EAP_TLV_RESULT_FAILURE;
195 ret->decision = DECISION_FAIL;
196 }
197 ret->methodState = METHOD_DONE;
198
199 *resp = eap_tlv_build_result(hdr->identifier, resp_status,
200 resp_len);
201 }
202
203 return 0;
204 }
205