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authorJouni Malinen <j@w1.fi>2010-11-13 09:36:37 (GMT)
committerJouni Malinen <j@w1.fi>2010-11-13 09:36:37 (GMT)
commit2924b0eb791bd100e9ce38dbd6f30b552252639e (patch)
tree0b04fe6a390fd512f1fd989c07f1c07caa494ad6 /wlantest/tkip.c
parenta9dd29d3e1eb0d7159e8dc0f06f131de553db884 (diff)
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wlantest: Add support for TKIP decryption
Diffstat (limited to 'wlantest/tkip.c')
-rw-r--r--wlantest/tkip.c394
1 files changed, 394 insertions, 0 deletions
diff --git a/wlantest/tkip.c b/wlantest/tkip.c
new file mode 100644
index 0000000..eb26dfa
--- /dev/null
+++ b/wlantest/tkip.c
@@ -0,0 +1,394 @@
+/*
+ * Temporal Key Integrity Protocol (CCMP)
+ * Copyright (c) 2010, Jouni Malinen <j@w1.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include "utils/includes.h"
+
+#include "utils/common.h"
+#include "common/ieee802_11_defs.h"
+#include "wlantest.h"
+
+
+static inline u16 RotR1(u16 val)
+{
+ return (val >> 1) | (val << 15);
+}
+
+
+static inline u8 Lo8(u16 val)
+{
+ return val & 0xff;
+}
+
+
+static inline u8 Hi8(u16 val)
+{
+ return val >> 8;
+}
+
+
+static inline u16 Lo16(u32 val)
+{
+ return val & 0xffff;
+}
+
+
+static inline u16 Hi16(u32 val)
+{
+ return val >> 16;
+}
+
+
+static inline u16 Mk16(u8 hi, u8 lo)
+{
+ return lo | (((u16) hi) << 8);
+}
+
+
+static inline u16 Mk16_le(u16 *v)
+{
+ return le_to_host16(*v);
+}
+
+
+static const u16 Sbox[256] =
+{
+ 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
+ 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
+ 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
+ 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
+ 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
+ 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
+ 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
+ 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
+ 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
+ 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
+ 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
+ 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
+ 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
+ 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
+ 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
+ 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
+ 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
+ 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
+ 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
+ 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
+ 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
+ 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
+ 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
+ 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
+ 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
+ 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
+ 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
+ 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
+ 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
+ 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
+ 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
+ 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
+};
+
+
+static inline u16 _S_(u16 v)
+{
+ u16 t = Sbox[Hi8(v)];
+ return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
+}
+
+
+#define PHASE1_LOOP_COUNT 8
+
+static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32)
+{
+ int i, j;
+
+ /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
+ TTAK[0] = Lo16(IV32);
+ TTAK[1] = Hi16(IV32);
+ TTAK[2] = Mk16(TA[1], TA[0]);
+ TTAK[3] = Mk16(TA[3], TA[2]);
+ TTAK[4] = Mk16(TA[5], TA[4]);
+
+ for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
+ j = 2 * (i & 1);
+ TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
+ TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
+ TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
+ TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
+ TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
+ }
+}
+
+
+static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK,
+ u16 IV16)
+{
+ u16 PPK[6];
+
+ /* Step 1 - make copy of TTAK and bring in TSC */
+ PPK[0] = TTAK[0];
+ PPK[1] = TTAK[1];
+ PPK[2] = TTAK[2];
+ PPK[3] = TTAK[3];
+ PPK[4] = TTAK[4];
+ PPK[5] = TTAK[4] + IV16;
+
+ /* Step 2 - 96-bit bijective mixing using S-box */
+ PPK[0] += _S_(PPK[5] ^ Mk16_le((u16 *) &TK[0]));
+ PPK[1] += _S_(PPK[0] ^ Mk16_le((u16 *) &TK[2]));
+ PPK[2] += _S_(PPK[1] ^ Mk16_le((u16 *) &TK[4]));
+ PPK[3] += _S_(PPK[2] ^ Mk16_le((u16 *) &TK[6]));
+ PPK[4] += _S_(PPK[3] ^ Mk16_le((u16 *) &TK[8]));
+ PPK[5] += _S_(PPK[4] ^ Mk16_le((u16 *) &TK[10]));
+
+ PPK[0] += RotR1(PPK[5] ^ Mk16_le((u16 *) &TK[12]));
+ PPK[1] += RotR1(PPK[0] ^ Mk16_le((u16 *) &TK[14]));
+ PPK[2] += RotR1(PPK[1]);
+ PPK[3] += RotR1(PPK[2]);
+ PPK[4] += RotR1(PPK[3]);
+ PPK[5] += RotR1(PPK[4]);
+
+ /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
+ * WEPSeed[0..2] is transmitted as WEP IV */
+ WEPSeed[0] = Hi8(IV16);
+ WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
+ WEPSeed[2] = Lo8(IV16);
+ WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((u16 *) &TK[0])) >> 1);
+ WPA_PUT_LE16(&WEPSeed[4], PPK[0]);
+ WPA_PUT_LE16(&WEPSeed[6], PPK[1]);
+ WPA_PUT_LE16(&WEPSeed[8], PPK[2]);
+ WPA_PUT_LE16(&WEPSeed[10], PPK[3]);
+ WPA_PUT_LE16(&WEPSeed[12], PPK[4]);
+ WPA_PUT_LE16(&WEPSeed[14], PPK[5]);
+}
+
+
+static void wep_crypt(u8 *key, u8 *buf, size_t plen)
+{
+ u32 i, j, k;
+ u8 S[256];
+#define S_SWAP(a,b) do { u8 t = S[a]; S[a] = S[b]; S[b] = t; } while(0)
+ u8 *pos;
+
+ /* Setup RC4 state */
+ for (i = 0; i < 256; i++)
+ S[i] = i;
+ j = 0;
+ for (i = 0; i < 256; i++) {
+ j = (j + S[i] + key[i & 0x0f]) & 0xff;
+ S_SWAP(i, j);
+ }
+
+ /* Apply RC4 to data */
+ pos = buf;
+ i = j = 0;
+ for (k = 0; k < plen; k++) {
+ i = (i + 1) & 0xff;
+ j = (j + S[i]) & 0xff;
+ S_SWAP(i, j);
+ *pos ^= S[(S[i] + S[j]) & 0xff];
+ pos++;
+ }
+}
+
+
+static inline u32 rotl(u32 val, int bits)
+{
+ return (val << bits) | (val >> (32 - bits));
+}
+
+
+static inline u32 rotr(u32 val, int bits)
+{
+ return (val >> bits) | (val << (32 - bits));
+}
+
+
+static inline u32 xswap(u32 val)
+{
+ return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8);
+}
+
+
+#define michael_block(l, r) \
+do { \
+ r ^= rotl(l, 17); \
+ l += r; \
+ r ^= xswap(l); \
+ l += r; \
+ r ^= rotl(l, 3); \
+ l += r; \
+ r ^= rotr(l, 2); \
+ l += r; \
+} while (0)
+
+
+static void michael_mic(const u8 *key, const u8 *hdr, const u8 *data,
+ size_t data_len, u8 *mic)
+{
+ u32 l, r;
+ int i, blocks, last;
+
+ l = WPA_GET_LE32(key);
+ r = WPA_GET_LE32(key + 4);
+
+ /* Michael MIC pseudo header: DA, SA, 3 x 0, Priority */
+ l ^= WPA_GET_LE32(hdr);
+ michael_block(l, r);
+ l ^= WPA_GET_LE32(&hdr[4]);
+ michael_block(l, r);
+ l ^= WPA_GET_LE32(&hdr[8]);
+ michael_block(l, r);
+ l ^= WPA_GET_LE32(&hdr[12]);
+ michael_block(l, r);
+
+ /* 32-bit blocks of data */
+ blocks = data_len / 4;
+ last = data_len % 4;
+ for (i = 0; i < blocks; i++) {
+ l ^= WPA_GET_LE32(&data[4 * i]);
+ michael_block(l, r);
+ }
+
+ /* Last block and padding (0x5a, 4..7 x 0) */
+ switch (last) {
+ case 0:
+ l ^= 0x5a;
+ break;
+ case 1:
+ l ^= data[4 * i] | 0x5a00;
+ break;
+ case 2:
+ l ^= data[4 * i] | (data[4 * i + 1] << 8) | 0x5a0000;
+ break;
+ case 3:
+ l ^= data[4 * i] | (data[4 * i + 1] << 8) |
+ (data[4 * i + 2] << 16) | 0x5a000000;
+ break;
+ }
+ michael_block(l, r);
+ /* l ^= 0; */
+ michael_block(l, r);
+
+ WPA_PUT_LE32(mic, l);
+ WPA_PUT_LE32(mic + 4, r);
+}
+
+
+static void michael_mic_hdr(const struct ieee80211_hdr *hdr11, u8 *hdr)
+{
+ int hdrlen = 24;
+ u16 fc = le_to_host16(hdr11->frame_control);
+
+ switch (fc & (WLAN_FC_FROMDS | WLAN_FC_TODS)) {
+ case WLAN_FC_TODS:
+ os_memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
+ os_memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
+ break;
+ case WLAN_FC_FROMDS:
+ os_memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
+ os_memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
+ break;
+ case WLAN_FC_FROMDS | WLAN_FC_TODS:
+ os_memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
+ os_memcpy(hdr + ETH_ALEN, hdr11 + 1, ETH_ALEN); /* SA */
+ hdrlen += ETH_ALEN;
+ break;
+ case 0:
+ os_memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
+ os_memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
+ break;
+ }
+
+ if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA &&
+ (WLAN_FC_GET_STYPE(fc) & 0x08)) {
+ const u8 *qos = ((const u8 *) hdr11) + hdrlen;
+ hdr[12] = qos[0] & 0x0f; /* priority */
+ } else
+ hdr[12] = 0; /* priority */
+
+ hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
+}
+
+
+u8 * tkip_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
+ const u8 *data, size_t data_len, size_t *decrypted_len)
+{
+ u16 iv16;
+ u32 iv32;
+ u16 ttak[5];
+ u8 rc4key[16];
+ u8 *plain;
+ size_t plain_len;
+ u32 icv, rx_icv;
+ const u8 *mic_key;
+ u8 michael_hdr[16];
+ u8 mic[8];
+ u16 fc = le_to_host16(hdr->frame_control);
+
+ if (data_len < 8 + 4)
+ return NULL;
+
+ iv16 = (data[0] << 8) | data[2];
+ iv32 = WPA_GET_LE32(&data[4]);
+ wpa_printf(MSG_EXCESSIVE, "TKIP decrypt: iv32=%08x iv16=%04x",
+ iv32, iv16);
+
+ tkip_mixing_phase1(ttak, tk, hdr->addr2, iv32);
+ wpa_hexdump(MSG_EXCESSIVE, "TKIP TTAK", (u8 *) ttak, sizeof(ttak));
+ tkip_mixing_phase2(rc4key, tk, ttak, iv16);
+ wpa_hexdump(MSG_EXCESSIVE, "TKIP RC4KEY", rc4key, sizeof(rc4key));
+
+ plain_len = data_len - 8;
+ plain = os_malloc(plain_len);
+ if (plain == NULL)
+ return NULL;
+ os_memcpy(plain, data + 8, plain_len);
+ wep_crypt(rc4key, plain, plain_len);
+
+ icv = crc32(plain, plain_len - 4);
+ rx_icv = WPA_GET_LE32(plain + plain_len - 4);
+ if (icv != rx_icv) {
+ wpa_printf(MSG_INFO, "TKIP ICV mismatch in frame from " MACSTR,
+ MAC2STR(hdr->addr2));
+ wpa_printf(MSG_DEBUG, "TKIP calculated ICV %08x received ICV "
+ "%08x", icv, rx_icv);
+ os_free(plain);
+ return NULL;
+ }
+ plain_len -= 4;
+
+ /* TODO: MSDU reassembly */
+
+ if (plain_len < 8) {
+ wpa_printf(MSG_INFO, "TKIP: Not enough room for Michael MIC "
+ "in a frame from " MACSTR, MAC2STR(hdr->addr2));
+ os_free(plain);
+ return NULL;
+ }
+
+ michael_mic_hdr(hdr, michael_hdr);
+ mic_key = tk + ((fc & WLAN_FC_FROMDS) ? 16 : 24);
+ michael_mic(mic_key, michael_hdr, plain, plain_len - 8, mic);
+ if (os_memcmp(mic, plain + plain_len - 8, 8) != 0) {
+ wpa_printf(MSG_INFO, "TKIP: Michael MIC mismatch in a frame "
+ "from " MACSTR, MAC2STR(hdr->addr2));
+ wpa_hexdump(MSG_DEBUG, "TKIP: Calculated MIC", mic, 8);
+ wpa_hexdump(MSG_DEBUG, "TKIP: Received MIC",
+ plain + plain_len - 8, 8);
+ os_free(plain);
+ return NULL;
+ }
+
+ *decrypted_len = plain_len - 8;
+ return plain;
+}