source: wpa_supplicant/vendor/current/src/crypto/milenage.c@ 793

Last change on this file since 793 was 793, checked in by andi.b@gmx.net, 11 years ago

wpa_supplicant: initial import of wpa_supplicant2.2
  • Property svn:eol-style set to native
File size: 9.5 KB
Line 
1/*
2 * 3GPP AKA - Milenage algorithm (3GPP TS 35.205, .206, .207, .208)
3 * Copyright (c) 2006-2007 <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 * This file implements an example authentication algorithm defined for 3GPP
9 * AKA. This can be used to implement a simple HLR/AuC into hlr_auc_gw to allow
10 * EAP-AKA to be tested properly with real USIM cards.
11 *
12 * This implementations assumes that the r1..r5 and c1..c5 constants defined in
13 * TS 35.206 are used, i.e., r1=64, r2=0, r3=32, r4=64, r5=96, c1=00..00,
14 * c2=00..01, c3=00..02, c4=00..04, c5=00..08. The block cipher is assumed to
15 * be AES (Rijndael).
16 */
17
18#include "includes.h"
19
20#include "common.h"
21#include "crypto/aes_wrap.h"
22#include "milenage.h"
23
24
25/**
26 * milenage_f1 - Milenage f1 and f1* algorithms
27 * @opc: OPc = 128-bit value derived from OP and K
28 * @k: K = 128-bit subscriber key
29 * @_rand: RAND = 128-bit random challenge
30 * @sqn: SQN = 48-bit sequence number
31 * @amf: AMF = 16-bit authentication management field
32 * @mac_a: Buffer for MAC-A = 64-bit network authentication code, or %NULL
33 * @mac_s: Buffer for MAC-S = 64-bit resync authentication code, or %NULL
34 * Returns: 0 on success, -1 on failure
35 */
36int milenage_f1(const u8 *opc, const u8 *k, const u8 *_rand,
37 const u8 *sqn, const u8 *amf, u8 *mac_a, u8 *mac_s)
38{
39 u8 tmp1[16], tmp2[16], tmp3[16];
40 int i;
41
42 /* tmp1 = TEMP = E_K(RAND XOR OP_C) */
43 for (i = 0; i < 16; i++)
44 tmp1[i] = _rand[i] ^ opc[i];
45 if (aes_128_encrypt_block(k, tmp1, tmp1))
46 return -1;
47
48 /* tmp2 = IN1 = SQN || AMF || SQN || AMF */
49 os_memcpy(tmp2, sqn, 6);
50 os_memcpy(tmp2 + 6, amf, 2);
51 os_memcpy(tmp2 + 8, tmp2, 8);
52
53 /* OUT1 = E_K(TEMP XOR rot(IN1 XOR OP_C, r1) XOR c1) XOR OP_C */
54
55 /* rotate (tmp2 XOR OP_C) by r1 (= 0x40 = 8 bytes) */
56 for (i = 0; i < 16; i++)
57 tmp3[(i + 8) % 16] = tmp2[i] ^ opc[i];
58 /* XOR with TEMP = E_K(RAND XOR OP_C) */
59 for (i = 0; i < 16; i++)
60 tmp3[i] ^= tmp1[i];
61 /* XOR with c1 (= ..00, i.e., NOP) */
62
63 /* f1 || f1* = E_K(tmp3) XOR OP_c */
64 if (aes_128_encrypt_block(k, tmp3, tmp1))
65 return -1;
66 for (i = 0; i < 16; i++)
67 tmp1[i] ^= opc[i];
68 if (mac_a)
69 os_memcpy(mac_a, tmp1, 8); /* f1 */
70 if (mac_s)
71 os_memcpy(mac_s, tmp1 + 8, 8); /* f1* */
72 return 0;
73}
74
75
76/**
77 * milenage_f2345 - Milenage f2, f3, f4, f5, f5* algorithms
78 * @opc: OPc = 128-bit value derived from OP and K
79 * @k: K = 128-bit subscriber key
80 * @_rand: RAND = 128-bit random challenge
81 * @res: Buffer for RES = 64-bit signed response (f2), or %NULL
82 * @ck: Buffer for CK = 128-bit confidentiality key (f3), or %NULL
83 * @ik: Buffer for IK = 128-bit integrity key (f4), or %NULL
84 * @ak: Buffer for AK = 48-bit anonymity key (f5), or %NULL
85 * @akstar: Buffer for AK = 48-bit anonymity key (f5*), or %NULL
86 * Returns: 0 on success, -1 on failure
87 */
88int milenage_f2345(const u8 *opc, const u8 *k, const u8 *_rand,
89 u8 *res, u8 *ck, u8 *ik, u8 *ak, u8 *akstar)
90{
91 u8 tmp1[16], tmp2[16], tmp3[16];
92 int i;
93
94 /* tmp2 = TEMP = E_K(RAND XOR OP_C) */
95 for (i = 0; i < 16; i++)
96 tmp1[i] = _rand[i] ^ opc[i];
97 if (aes_128_encrypt_block(k, tmp1, tmp2))
98 return -1;
99
100 /* OUT2 = E_K(rot(TEMP XOR OP_C, r2) XOR c2) XOR OP_C */
101 /* OUT3 = E_K(rot(TEMP XOR OP_C, r3) XOR c3) XOR OP_C */
102 /* OUT4 = E_K(rot(TEMP XOR OP_C, r4) XOR c4) XOR OP_C */
103 /* OUT5 = E_K(rot(TEMP XOR OP_C, r5) XOR c5) XOR OP_C */
104
105 /* f2 and f5 */
106 /* rotate by r2 (= 0, i.e., NOP) */
107 for (i = 0; i < 16; i++)
108 tmp1[i] = tmp2[i] ^ opc[i];
109 tmp1[15] ^= 1; /* XOR c2 (= ..01) */
110 /* f5 || f2 = E_K(tmp1) XOR OP_c */
111 if (aes_128_encrypt_block(k, tmp1, tmp3))
112 return -1;
113 for (i = 0; i < 16; i++)
114 tmp3[i] ^= opc[i];
115 if (res)
116 os_memcpy(res, tmp3 + 8, 8); /* f2 */
117 if (ak)
118 os_memcpy(ak, tmp3, 6); /* f5 */
119
120 /* f3 */
121 if (ck) {
122 /* rotate by r3 = 0x20 = 4 bytes */
123 for (i = 0; i < 16; i++)
124 tmp1[(i + 12) % 16] = tmp2[i] ^ opc[i];
125 tmp1[15] ^= 2; /* XOR c3 (= ..02) */
126 if (aes_128_encrypt_block(k, tmp1, ck))
127 return -1;
128 for (i = 0; i < 16; i++)
129 ck[i] ^= opc[i];
130 }
131
132 /* f4 */
133 if (ik) {
134 /* rotate by r4 = 0x40 = 8 bytes */
135 for (i = 0; i < 16; i++)
136 tmp1[(i + 8) % 16] = tmp2[i] ^ opc[i];
137 tmp1[15] ^= 4; /* XOR c4 (= ..04) */
138 if (aes_128_encrypt_block(k, tmp1, ik))
139 return -1;
140 for (i = 0; i < 16; i++)
141 ik[i] ^= opc[i];
142 }
143
144 /* f5* */
145 if (akstar) {
146 /* rotate by r5 = 0x60 = 12 bytes */
147 for (i = 0; i < 16; i++)
148 tmp1[(i + 4) % 16] = tmp2[i] ^ opc[i];
149 tmp1[15] ^= 8; /* XOR c5 (= ..08) */
150 if (aes_128_encrypt_block(k, tmp1, tmp1))
151 return -1;
152 for (i = 0; i < 6; i++)
153 akstar[i] = tmp1[i] ^ opc[i];
154 }
155
156 return 0;
157}
158
159
160/**
161 * milenage_generate - Generate AKA AUTN,IK,CK,RES
162 * @opc: OPc = 128-bit operator variant algorithm configuration field (encr.)
163 * @amf: AMF = 16-bit authentication management field
164 * @k: K = 128-bit subscriber key
165 * @sqn: SQN = 48-bit sequence number
166 * @_rand: RAND = 128-bit random challenge
167 * @autn: Buffer for AUTN = 128-bit authentication token
168 * @ik: Buffer for IK = 128-bit integrity key (f4), or %NULL
169 * @ck: Buffer for CK = 128-bit confidentiality key (f3), or %NULL
170 * @res: Buffer for RES = 64-bit signed response (f2), or %NULL
171 * @res_len: Max length for res; set to used length or 0 on failure
172 */
173void milenage_generate(const u8 *opc, const u8 *amf, const u8 *k,
174 const u8 *sqn, const u8 *_rand, u8 *autn, u8 *ik,
175 u8 *ck, u8 *res, size_t *res_len)
176{
177 int i;
178 u8 mac_a[8], ak[6];
179
180 if (*res_len < 8) {
181 *res_len = 0;
182 return;
183 }
184 if (milenage_f1(opc, k, _rand, sqn, amf, mac_a, NULL) ||
185 milenage_f2345(opc, k, _rand, res, ck, ik, ak, NULL)) {
186 *res_len = 0;
187 return;
188 }
189 *res_len = 8;
190
191 /* AUTN = (SQN ^ AK) || AMF || MAC */
192 for (i = 0; i < 6; i++)
193 autn[i] = sqn[i] ^ ak[i];
194 os_memcpy(autn + 6, amf, 2);
195 os_memcpy(autn + 8, mac_a, 8);
196}
197
198
199/**
200 * milenage_auts - Milenage AUTS validation
201 * @opc: OPc = 128-bit operator variant algorithm configuration field (encr.)
202 * @k: K = 128-bit subscriber key
203 * @_rand: RAND = 128-bit random challenge
204 * @auts: AUTS = 112-bit authentication token from client
205 * @sqn: Buffer for SQN = 48-bit sequence number
206 * Returns: 0 = success (sqn filled), -1 on failure
207 */
208int milenage_auts(const u8 *opc, const u8 *k, const u8 *_rand, const u8 *auts,
209 u8 *sqn)
210{
211 u8 amf[2] = { 0x00, 0x00 }; /* TS 33.102 v7.0.0, 6.3.3 */
212 u8 ak[6], mac_s[8];
213 int i;
214
215 if (milenage_f2345(opc, k, _rand, NULL, NULL, NULL, NULL, ak))
216 return -1;
217 for (i = 0; i < 6; i++)
218 sqn[i] = auts[i] ^ ak[i];
219 if (milenage_f1(opc, k, _rand, sqn, amf, NULL, mac_s) ||
220 memcmp(mac_s, auts + 6, 8) != 0)
221 return -1;
222 return 0;
223}
224
225
226/**
227 * gsm_milenage - Generate GSM-Milenage (3GPP TS 55.205) authentication triplet
228 * @opc: OPc = 128-bit operator variant algorithm configuration field (encr.)
229 * @k: K = 128-bit subscriber key
230 * @_rand: RAND = 128-bit random challenge
231 * @sres: Buffer for SRES = 32-bit SRES
232 * @kc: Buffer for Kc = 64-bit Kc
233 * Returns: 0 on success, -1 on failure
234 */
235int gsm_milenage(const u8 *opc, const u8 *k, const u8 *_rand, u8 *sres, u8 *kc)
236{
237 u8 res[8], ck[16], ik[16];
238 int i;
239
240 if (milenage_f2345(opc, k, _rand, res, ck, ik, NULL, NULL))
241 return -1;
242
243 for (i = 0; i < 8; i++)
244 kc[i] = ck[i] ^ ck[i + 8] ^ ik[i] ^ ik[i + 8];
245
246#ifdef GSM_MILENAGE_ALT_SRES
247 os_memcpy(sres, res, 4);
248#else /* GSM_MILENAGE_ALT_SRES */
249 for (i = 0; i < 4; i++)
250 sres[i] = res[i] ^ res[i + 4];
251#endif /* GSM_MILENAGE_ALT_SRES */
252 return 0;
253}
254
255
256/**
257 * milenage_generate - Generate AKA AUTN,IK,CK,RES
258 * @opc: OPc = 128-bit operator variant algorithm configuration field (encr.)
259 * @k: K = 128-bit subscriber key
260 * @sqn: SQN = 48-bit sequence number
261 * @_rand: RAND = 128-bit random challenge
262 * @autn: AUTN = 128-bit authentication token
263 * @ik: Buffer for IK = 128-bit integrity key (f4), or %NULL
264 * @ck: Buffer for CK = 128-bit confidentiality key (f3), or %NULL
265 * @res: Buffer for RES = 64-bit signed response (f2), or %NULL
266 * @res_len: Variable that will be set to RES length
267 * @auts: 112-bit buffer for AUTS
268 * Returns: 0 on success, -1 on failure, or -2 on synchronization failure
269 */
270int milenage_check(const u8 *opc, const u8 *k, const u8 *sqn, const u8 *_rand,
271 const u8 *autn, u8 *ik, u8 *ck, u8 *res, size_t *res_len,
272 u8 *auts)
273{
274 int i;
275 u8 mac_a[8], ak[6], rx_sqn[6];
276 const u8 *amf;
277
278 wpa_hexdump(MSG_DEBUG, "Milenage: AUTN", autn, 16);
279 wpa_hexdump(MSG_DEBUG, "Milenage: RAND", _rand, 16);
280
281 if (milenage_f2345(opc, k, _rand, res, ck, ik, ak, NULL))
282 return -1;
283
284 *res_len = 8;
285 wpa_hexdump_key(MSG_DEBUG, "Milenage: RES", res, *res_len);
286 wpa_hexdump_key(MSG_DEBUG, "Milenage: CK", ck, 16);
287 wpa_hexdump_key(MSG_DEBUG, "Milenage: IK", ik, 16);
288 wpa_hexdump_key(MSG_DEBUG, "Milenage: AK", ak, 6);
289
290 /* AUTN = (SQN ^ AK) || AMF || MAC */
291 for (i = 0; i < 6; i++)
292 rx_sqn[i] = autn[i] ^ ak[i];
293 wpa_hexdump(MSG_DEBUG, "Milenage: SQN", rx_sqn, 6);
294
295 if (os_memcmp(rx_sqn, sqn, 6) <= 0) {
296 u8 auts_amf[2] = { 0x00, 0x00 }; /* TS 33.102 v7.0.0, 6.3.3 */
297 if (milenage_f2345(opc, k, _rand, NULL, NULL, NULL, NULL, ak))
298 return -1;
299 wpa_hexdump_key(MSG_DEBUG, "Milenage: AK*", ak, 6);
300 for (i = 0; i < 6; i++)
301 auts[i] = sqn[i] ^ ak[i];
302 if (milenage_f1(opc, k, _rand, sqn, auts_amf, NULL, auts + 6))
303 return -1;
304 wpa_hexdump(MSG_DEBUG, "Milenage: AUTS", auts, 14);
305 return -2;
306 }
307
308 amf = autn + 6;
309 wpa_hexdump(MSG_DEBUG, "Milenage: AMF", amf, 2);
310 if (milenage_f1(opc, k, _rand, rx_sqn, amf, mac_a, NULL))
311 return -1;
312
313 wpa_hexdump(MSG_DEBUG, "Milenage: MAC_A", mac_a, 8);
314
315 if (os_memcmp(mac_a, autn + 8, 8) != 0) {
316 wpa_printf(MSG_DEBUG, "Milenage: MAC mismatch");
317 wpa_hexdump(MSG_DEBUG, "Milenage: Received MAC_A",
318 autn + 8, 8);
319 return -1;
320 }
321
322 return 0;
323}
Note: See TracBrowser for help on using the repository browser.