2 * CTR with CBC-MAC Protocol (CCMP)
3 * Copyright (c) 2010-2012, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
9 #include "utils/includes.h"
11 #include "utils/common.h"
12 #include "common/ieee802_11_defs.h"
13 #include "crypto/aes.h"
14 #include "crypto/aes_wrap.h"
18 static void ccmp_aad_nonce(const struct ieee80211_hdr *hdr, const u8 *data,
19 u8 *aad, size_t *aad_len, u8 *nonce)
22 int qos = 0, addr4 = 0;
27 fc = le_to_host16(hdr->frame_control);
28 stype = WLAN_FC_GET_STYPE(fc);
29 if ((fc & (WLAN_FC_TODS | WLAN_FC_FROMDS)) ==
30 (WLAN_FC_TODS | WLAN_FC_FROMDS))
33 if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA) {
34 fc &= ~0x0070; /* Mask subtype bits */
39 qc = (const u8 *) (hdr + 1);
42 nonce[0] = qc[0] & 0x0f;
44 } else if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_MGMT)
45 nonce[0] |= 0x10; /* Management */
47 fc &= ~(WLAN_FC_RETRY | WLAN_FC_PWRMGT | WLAN_FC_MOREDATA);
49 WPA_PUT_LE16(aad, fc);
51 os_memcpy(pos, hdr->addr1, 3 * ETH_ALEN);
53 seq = le_to_host16(hdr->seq_ctrl);
54 seq &= ~0xfff0; /* Mask Seq#; do not modify Frag# */
55 WPA_PUT_LE16(pos, seq);
58 os_memcpy(pos, hdr + 1, addr4 * ETH_ALEN + qos * 2);
59 pos += addr4 * ETH_ALEN;
62 if (1 /* FIX: either device has SPP A-MSDU Capab = 0 */)
70 os_memcpy(nonce + 1, hdr->addr2, ETH_ALEN);
71 nonce[7] = data[7]; /* PN5 */
72 nonce[8] = data[6]; /* PN4 */
73 nonce[9] = data[5]; /* PN3 */
74 nonce[10] = data[4]; /* PN2 */
75 nonce[11] = data[1]; /* PN1 */
76 nonce[12] = data[0]; /* PN0 */
80 u8 * ccmp_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
81 const u8 *data, size_t data_len, size_t *decrypted_len)
83 u8 aad[30], nonce[13];
91 plain = os_malloc(data_len + AES_BLOCK_SIZE);
95 mlen = data_len - 8 - 8;
97 os_memset(aad, 0, sizeof(aad));
98 ccmp_aad_nonce(hdr, data, aad, &aad_len, nonce);
99 wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", aad, aad_len);
100 wpa_hexdump(MSG_EXCESSIVE, "CCMP nonce", nonce, 13);
102 if (aes_ccm_ad(tk, 16, nonce, 8, data + 8, mlen, aad, aad_len,
103 data + 8 + mlen, plain) < 0) {
104 u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
105 wpa_printf(MSG_INFO, "Invalid CCMP MIC in frame: A1=" MACSTR
106 " A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u",
107 MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
109 WLAN_GET_SEQ_SEQ(seq_ctrl),
110 WLAN_GET_SEQ_FRAG(seq_ctrl));
114 wpa_hexdump(MSG_EXCESSIVE, "CCMP decrypted", plain, mlen);
116 *decrypted_len = mlen;
121 void ccmp_get_pn(u8 *pn, const u8 *data)
123 pn[0] = data[7]; /* PN5 */
124 pn[1] = data[6]; /* PN4 */
125 pn[2] = data[5]; /* PN3 */
126 pn[3] = data[4]; /* PN2 */
127 pn[4] = data[1]; /* PN1 */
128 pn[5] = data[0]; /* PN0 */
132 u8 * ccmp_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen, u8 *qos,
133 u8 *pn, int keyid, size_t *encrypted_len)
135 u8 aad[30], nonce[13];
136 size_t aad_len, plen;
138 struct ieee80211_hdr *hdr;
140 if (len < hdrlen || hdrlen < 24)
144 crypt = os_malloc(hdrlen + 8 + plen + 8 + AES_BLOCK_SIZE);
148 os_memcpy(crypt, frame, hdrlen);
149 hdr = (struct ieee80211_hdr *) crypt;
150 hdr->frame_control |= host_to_le16(WLAN_FC_ISWEP);
151 pos = crypt + hdrlen;
152 *pos++ = pn[5]; /* PN0 */
153 *pos++ = pn[4]; /* PN1 */
154 *pos++ = 0x00; /* Rsvd */
155 *pos++ = 0x20 | (keyid << 6);
156 *pos++ = pn[3]; /* PN2 */
157 *pos++ = pn[2]; /* PN3 */
158 *pos++ = pn[1]; /* PN4 */
159 *pos++ = pn[0]; /* PN5 */
161 os_memset(aad, 0, sizeof(aad));
162 ccmp_aad_nonce(hdr, crypt + hdrlen, aad, &aad_len, nonce);
163 wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", aad, aad_len);
164 wpa_hexdump(MSG_EXCESSIVE, "CCMP nonce", nonce, 13);
166 if (aes_ccm_ae(tk, 16, nonce, 8, frame + hdrlen, plen, aad, aad_len,
167 pos, pos + plen) < 0) {
172 wpa_hexdump(MSG_EXCESSIVE, "CCMP encrypted", crypt + hdrlen + 8, plen);
174 *encrypted_len = hdrlen + 8 + plen + 8;
180 u8 * ccmp_256_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
181 const u8 *data, size_t data_len, size_t *decrypted_len)
183 u8 aad[30], nonce[13];
188 if (data_len < 8 + 16)
191 plain = os_malloc(data_len + AES_BLOCK_SIZE);
195 mlen = data_len - 8 - 16;
197 os_memset(aad, 0, sizeof(aad));
198 ccmp_aad_nonce(hdr, data, aad, &aad_len, nonce);
199 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 AAD", aad, aad_len);
200 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 nonce", nonce, 13);
202 if (aes_ccm_ad(tk, 32, nonce, 16, data + 8, mlen, aad, aad_len,
203 data + 8 + mlen, plain) < 0) {
204 u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
205 wpa_printf(MSG_INFO, "Invalid CCMP-256 MIC in frame: A1=" MACSTR
206 " A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u",
207 MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
209 WLAN_GET_SEQ_SEQ(seq_ctrl),
210 WLAN_GET_SEQ_FRAG(seq_ctrl));
214 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 decrypted", plain, mlen);
216 *decrypted_len = mlen;
221 u8 * ccmp_256_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen,
222 u8 *qos, u8 *pn, int keyid, size_t *encrypted_len)
224 u8 aad[30], nonce[13];
225 size_t aad_len, plen;
227 struct ieee80211_hdr *hdr;
229 if (len < hdrlen || hdrlen < 24)
233 crypt = os_malloc(hdrlen + 8 + plen + 16 + AES_BLOCK_SIZE);
237 os_memcpy(crypt, frame, hdrlen);
238 hdr = (struct ieee80211_hdr *) crypt;
239 hdr->frame_control |= host_to_le16(WLAN_FC_ISWEP);
240 pos = crypt + hdrlen;
241 *pos++ = pn[5]; /* PN0 */
242 *pos++ = pn[4]; /* PN1 */
243 *pos++ = 0x00; /* Rsvd */
244 *pos++ = 0x20 | (keyid << 6);
245 *pos++ = pn[3]; /* PN2 */
246 *pos++ = pn[2]; /* PN3 */
247 *pos++ = pn[1]; /* PN4 */
248 *pos++ = pn[0]; /* PN5 */
250 os_memset(aad, 0, sizeof(aad));
251 ccmp_aad_nonce(hdr, crypt + hdrlen, aad, &aad_len, nonce);
252 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 AAD", aad, aad_len);
253 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 nonce", nonce, 13);
255 if (aes_ccm_ae(tk, 32, nonce, 16, frame + hdrlen, plen, aad, aad_len,
256 pos, pos + plen) < 0) {
261 wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 encrypted", crypt + hdrlen + 8,
264 *encrypted_len = hdrlen + 8 + plen + 16;