1 /*
2 * CTR with CBC-MAC Protocol (CCMP)
3 * Copyright (c) 2010-2012, 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 "utils/includes.h"
10
11 #include "utils/common.h"
12 #include "common/ieee802_11_defs.h"
13 #include "crypto/aes.h"
14 #include "crypto/aes_wrap.h"
15 #include "wlantest.h"
16
17
ccmp_aad_nonce(const struct ieee80211_hdr * hdr,const u8 * data,const u8 * a1,const u8 * a2,const u8 * a3,u8 * aad,size_t * aad_len,u8 * nonce)18 static void ccmp_aad_nonce(const struct ieee80211_hdr *hdr, const u8 *data,
19 const u8 *a1, const u8 *a2, const u8 *a3,
20 u8 *aad, size_t *aad_len, u8 *nonce)
21 {
22 u16 fc, stype, seq;
23 int qos = 0, addr4 = 0;
24 u8 *pos;
25
26 nonce[0] = 0;
27
28 fc = le_to_host16(hdr->frame_control);
29 stype = WLAN_FC_GET_STYPE(fc);
30 if ((fc & (WLAN_FC_TODS | WLAN_FC_FROMDS)) ==
31 (WLAN_FC_TODS | WLAN_FC_FROMDS))
32 addr4 = 1;
33
34 if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA) {
35 fc &= ~0x0070; /* Mask subtype bits */
36 if (stype & 0x08) {
37 const u8 *qc;
38 qos = 1;
39 fc &= ~WLAN_FC_HTC;
40 qc = (const u8 *) (hdr + 1);
41 if (addr4)
42 qc += ETH_ALEN;
43 nonce[0] = qc[0] & 0x0f;
44 }
45 } else if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_MGMT)
46 nonce[0] |= 0x10; /* Management */
47
48 fc &= ~(WLAN_FC_RETRY | WLAN_FC_PWRMGT | WLAN_FC_MOREDATA);
49 fc |= WLAN_FC_ISWEP;
50 WPA_PUT_LE16(aad, fc);
51 pos = aad + 2;
52 os_memcpy(pos, hdr->addr1, 3 * ETH_ALEN);
53 if (a1)
54 os_memcpy(pos, a1, ETH_ALEN);
55 if (a2)
56 os_memcpy(pos + ETH_ALEN, a2, ETH_ALEN);
57 if (a3)
58 os_memcpy(pos + 2 * ETH_ALEN, a3, ETH_ALEN);
59 pos += 3 * ETH_ALEN;
60 seq = le_to_host16(hdr->seq_ctrl);
61 seq &= ~0xfff0; /* Mask Seq#; do not modify Frag# */
62 WPA_PUT_LE16(pos, seq);
63 pos += 2;
64
65 os_memcpy(pos, hdr + 1, addr4 * ETH_ALEN + qos * 2);
66 pos += addr4 * ETH_ALEN;
67 if (qos) {
68 pos[0] &= ~0x70;
69 if (1 /* FIX: either device has SPP A-MSDU Capab = 0 */)
70 pos[0] &= ~0x80;
71 pos++;
72 *pos++ = 0x00;
73 }
74
75 *aad_len = pos - aad;
76
77 if (a2)
78 os_memcpy(nonce + 1, a2, ETH_ALEN);
79 else
80 os_memcpy(nonce + 1, hdr->addr2, ETH_ALEN);
81 nonce[7] = data[7]; /* PN5 */
82 nonce[8] = data[6]; /* PN4 */
83 nonce[9] = data[5]; /* PN3 */
84 nonce[10] = data[4]; /* PN2 */
85 nonce[11] = data[1]; /* PN1 */
86 nonce[12] = data[0]; /* PN0 */
87 }
88
89
ccmp_aad_nonce_pv1(const u8 * hdr,const u8 * a1,const u8 * a2,const u8 * a3,const u8 * pn,u8 * aad,size_t * aad_len,u8 * nonce)90 static void ccmp_aad_nonce_pv1(const u8 *hdr, const u8 *a1, const u8 *a2,
91 const u8 *a3, const u8 *pn,
92 u8 *aad, size_t *aad_len, u8 *nonce)
93 {
94 u16 fc, type, ptid;
95 u8 *pos;
96
97 nonce[0] = BIT(5); /* PV1 */
98 /* TODO: Priority for QMF; 0 is used for Data frames */
99
100 fc = WPA_GET_LE16(hdr);
101 type = (fc & (BIT(2) | BIT(3) | BIT(4))) >> 2;
102
103 if (type == 1)
104 nonce[0] |= 0x10; /* Management */
105 else if ((type == 0) || (type == 3)) {
106 /* QoS Data */
107 ptid = (fc & (BIT(5) | BIT(6) | BIT(7))) >> 5;
108 nonce[0] |= ptid;
109 }
110
111 fc &= ~(BIT(10) | BIT(11) | BIT(13) | BIT(14) | BIT(15));
112 fc |= BIT(12);
113 WPA_PUT_LE16(aad, fc);
114 pos = aad + 2;
115 if (type == 0 || type == 3) {
116 const u8 *sc;
117
118 os_memcpy(pos, a1, ETH_ALEN);
119 pos += ETH_ALEN;
120 os_memcpy(pos, a2, ETH_ALEN);
121 pos += ETH_ALEN;
122
123 if (type == 0) {
124 /* Either A1 or A2 contains SID */
125 sc = hdr + 2 + 2 + ETH_ALEN;
126 } else {
127 /* Both A1 and A2 contain full addresses */
128 sc = hdr + 2 + 2 * ETH_ALEN;
129 }
130 /* SC with Sequence Number subfield (bits 4-15 of the Sequence
131 * Control field) masked to 0. */
132 *pos++ = *sc & 0x0f;
133 *pos++ = 0;
134
135 if (a3) {
136 os_memcpy(pos, a3, ETH_ALEN);
137 pos += ETH_ALEN;
138 }
139 }
140
141 *aad_len = pos - aad;
142
143 os_memcpy(nonce + 1, a2, ETH_ALEN);
144 nonce[7] = pn[5]; /* PN5 */
145 nonce[8] = pn[4]; /* PN4 */
146 nonce[9] = pn[3]; /* PN3 */
147 nonce[10] = pn[2]; /* PN2 */
148 nonce[11] = pn[1]; /* PN1 */
149 nonce[12] = pn[0]; /* PN0 */
150 }
151
152
ccmp_decrypt(const u8 * tk,const struct ieee80211_hdr * hdr,const u8 * a1,const u8 * a2,const u8 * a3,const u8 * data,size_t data_len,size_t * decrypted_len)153 u8 * ccmp_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
154 const u8 *a1, const u8 *a2, const u8 *a3,
155 const u8 *data, size_t data_len,
156 size_t *decrypted_len)
157 {
158 u8 aad[30], nonce[13];
159 size_t aad_len;
160 size_t mlen;
161 u8 *plain;
162
163 if (data_len < 8 + 8)
164 return NULL;
165
166 plain = os_malloc(data_len + AES_BLOCK_SIZE);
167 if (plain == NULL)
168 return NULL;
169
170 mlen = data_len - 8 - 8;
171
172 os_memset(aad, 0, sizeof(aad));
173 ccmp_aad_nonce(hdr, data, a1, a2, a3, aad, &aad_len, nonce);
174 wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", aad, aad_len);
175 wpa_hexdump(MSG_EXCESSIVE, "CCM Nonce", nonce, 13);
176
177 if (aes_ccm_ad(tk, 16, nonce, 8, data + 8, mlen, aad, aad_len,
178 data + 8 + mlen, plain) < 0) {
179 u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
180 wpa_printf(MSG_INFO, "Invalid CCMP MIC in frame: A1=" MACSTR
181 " A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u",
182 MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
183 MAC2STR(hdr->addr3),
184 WLAN_GET_SEQ_SEQ(seq_ctrl),
185 WLAN_GET_SEQ_FRAG(seq_ctrl));
186 os_free(plain);
187 return NULL;
188 }
189 wpa_hexdump(MSG_EXCESSIVE, "CCMP decrypted", plain, mlen);
190
191 *decrypted_len = mlen;
192 return plain;
193 }
194
195
ccmp_get_pn(u8 * pn,const u8 * data)196 void ccmp_get_pn(u8 *pn, const u8 *data)
197 {
198 pn[0] = data[7]; /* PN5 */
199 pn[1] = data[6]; /* PN4 */
200 pn[2] = data[5]; /* PN3 */
201 pn[3] = data[4]; /* PN2 */
202 pn[4] = data[1]; /* PN1 */
203 pn[5] = data[0]; /* PN0 */
204 }
205
206
ccmp_encrypt(const u8 * tk,u8 * frame,size_t len,size_t hdrlen,const u8 * qos,const u8 * a1,const u8 * a2,const u8 * a3,const u8 * pn,int keyid,size_t * encrypted_len)207 u8 * ccmp_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen,
208 const u8 *qos, const u8 *a1, const u8 *a2, const u8 *a3,
209 const u8 *pn, int keyid, size_t *encrypted_len)
210 {
211 u8 aad[30], nonce[13];
212 size_t aad_len, plen;
213 u8 *crypt, *pos;
214 struct ieee80211_hdr *hdr;
215
216 if (len < hdrlen || hdrlen < 24)
217 return NULL;
218 plen = len - hdrlen;
219
220 crypt = os_malloc(hdrlen + 8 + plen + 8 + AES_BLOCK_SIZE);
221 if (crypt == NULL)
222 return NULL;
223
224 os_memcpy(crypt, frame, hdrlen);
225 hdr = (struct ieee80211_hdr *) crypt;
226 hdr->frame_control |= host_to_le16(WLAN_FC_ISWEP);
227 pos = crypt + hdrlen;
228 *pos++ = pn[5]; /* PN0 */
229 *pos++ = pn[4]; /* PN1 */
230 *pos++ = 0x00; /* Rsvd */
231 *pos++ = 0x20 | (keyid << 6);
232 *pos++ = pn[3]; /* PN2 */
233 *pos++ = pn[2]; /* PN3 */
234 *pos++ = pn[1]; /* PN4 */
235 *pos++ = pn[0]; /* PN5 */
236
237 os_memset(aad, 0, sizeof(aad));
238 ccmp_aad_nonce(hdr, crypt + hdrlen, a1, a2, a3, aad, &aad_len, nonce);
239 wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", aad, aad_len);
240 wpa_hexdump(MSG_EXCESSIVE, "CCM Nonce", nonce, 13);
241
242 if (aes_ccm_ae(tk, 16, nonce, 8, frame + hdrlen, plen, aad, aad_len,
243 pos, pos + plen) < 0) {
244 os_free(crypt);
245 return NULL;
246 }
247
248 wpa_hexdump(MSG_EXCESSIVE, "CCMP encrypted", crypt + hdrlen + 8, plen);
249
250 *encrypted_len = hdrlen + 8 + plen + 8;
251
252 return crypt;
253 }
254
255
ccmp_encrypt_pv1(const u8 * tk,const u8 * a1,const u8 * a2,const u8 * a3,const u8 * frame,size_t len,size_t hdrlen,const u8 * pn,int keyid,size_t * encrypted_len)256 u8 * ccmp_encrypt_pv1(const u8 *tk, const u8 *a1, const u8 *a2, const u8 *a3,
257 const u8 *frame, size_t len,
258 size_t hdrlen, const u8 *pn, int keyid,
259 size_t *encrypted_len)
260 {
261 u8 aad[24], nonce[13];
262 size_t aad_len, plen;
263 u8 *crypt, *pos;
264 struct ieee80211_hdr *hdr;
265
266 if (len < hdrlen || hdrlen < 12)
267 return NULL;
268 plen = len - hdrlen;
269
270 crypt = os_malloc(hdrlen + plen + 8 + AES_BLOCK_SIZE);
271 if (crypt == NULL)
272 return NULL;
273
274 os_memcpy(crypt, frame, hdrlen);
275 hdr = (struct ieee80211_hdr *) crypt;
276 hdr->frame_control |= host_to_le16(BIT(12)); /* Protected Frame */
277 pos = crypt + hdrlen;
278
279 os_memset(aad, 0, sizeof(aad));
280 ccmp_aad_nonce_pv1(crypt, a1, a2, a3, pn, aad, &aad_len, nonce);
281 wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", aad, aad_len);
282 wpa_hexdump(MSG_EXCESSIVE, "CCM Nonce", nonce, sizeof(nonce));
283
284 if (aes_ccm_ae(tk, 16, nonce, 8, frame + hdrlen, plen, aad, aad_len,
285 pos, pos + plen) < 0) {
286 os_free(crypt);
287 return NULL;
288 }
289
290 wpa_hexdump(MSG_EXCESSIVE, "CCMP encrypted", crypt + hdrlen, plen);
291
292 *encrypted_len = hdrlen + plen + 8;
293
294 return crypt;
295 }
296
297
ccmp_256_decrypt(const u8 * tk,const struct ieee80211_hdr * hdr,const u8 * a1,const u8 * a2,const u8 * a3,const u8 * data,size_t data_len,size_t * decrypted_len)298 u8 * ccmp_256_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
299 const u8 *a1, const u8 *a2, const u8 *a3,
300 const u8 *data, size_t data_len, size_t *decrypted_len)
301 {
302 u8 aad[30], nonce[13];
303 size_t aad_len;
304 size_t mlen;
305 u8 *plain;
306
307 if (data_len < 8 + 16)
308 return NULL;
309
310 plain = os_malloc(data_len + AES_BLOCK_SIZE);
311 if (plain == NULL)
312 return NULL;
313
314 mlen = data_len - 8 - 16;
315
316 os_memset(aad, 0, sizeof(aad));
317 ccmp_aad_nonce(hdr, data, a1, a2, a3, aad, &aad_len, nonce);
318 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 AAD", aad, aad_len);
319 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 nonce", nonce, 13);
320
321 if (aes_ccm_ad(tk, 32, nonce, 16, data + 8, mlen, aad, aad_len,
322 data + 8 + mlen, plain) < 0) {
323 u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
324 wpa_printf(MSG_INFO, "Invalid CCMP-256 MIC in frame: A1=" MACSTR
325 " A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u",
326 MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
327 MAC2STR(hdr->addr3),
328 WLAN_GET_SEQ_SEQ(seq_ctrl),
329 WLAN_GET_SEQ_FRAG(seq_ctrl));
330 os_free(plain);
331 return NULL;
332 }
333 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 decrypted", plain, mlen);
334
335 *decrypted_len = mlen;
336 return plain;
337 }
338
339
ccmp_256_encrypt(const u8 * tk,u8 * frame,size_t len,size_t hdrlen,const u8 * qos,const u8 * a1,const u8 * a2,const u8 * a3,const u8 * pn,int keyid,size_t * encrypted_len)340 u8 * ccmp_256_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen,
341 const u8 *qos, const u8 *a1, const u8 *a2, const u8 *a3,
342 const u8 *pn, int keyid, size_t *encrypted_len)
343 {
344 u8 aad[30], nonce[13];
345 size_t aad_len, plen;
346 u8 *crypt, *pos;
347 struct ieee80211_hdr *hdr;
348
349 if (len < hdrlen || hdrlen < 24)
350 return NULL;
351 plen = len - hdrlen;
352
353 crypt = os_malloc(hdrlen + 8 + plen + 16 + AES_BLOCK_SIZE);
354 if (crypt == NULL)
355 return NULL;
356
357 os_memcpy(crypt, frame, hdrlen);
358 hdr = (struct ieee80211_hdr *) crypt;
359 hdr->frame_control |= host_to_le16(WLAN_FC_ISWEP);
360 pos = crypt + hdrlen;
361 *pos++ = pn[5]; /* PN0 */
362 *pos++ = pn[4]; /* PN1 */
363 *pos++ = 0x00; /* Rsvd */
364 *pos++ = 0x20 | (keyid << 6);
365 *pos++ = pn[3]; /* PN2 */
366 *pos++ = pn[2]; /* PN3 */
367 *pos++ = pn[1]; /* PN4 */
368 *pos++ = pn[0]; /* PN5 */
369
370 os_memset(aad, 0, sizeof(aad));
371 ccmp_aad_nonce(hdr, crypt + hdrlen, a1, a2, a3, aad, &aad_len, nonce);
372 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 AAD", aad, aad_len);
373 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 nonce", nonce, 13);
374
375 if (aes_ccm_ae(tk, 32, nonce, 16, frame + hdrlen, plen, aad, aad_len,
376 pos, pos + plen) < 0) {
377 os_free(crypt);
378 return NULL;
379 }
380
381 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 encrypted", crypt + hdrlen + 8,
382 plen);
383
384 *encrypted_len = hdrlen + 8 + plen + 16;
385
386 return crypt;
387 }
388
