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