1 /*
2 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
3 * Copyright (c) 2006 CACE Technologies, Davis (California)
4 * All rights reserved.
5 *
6 * SPDX-License-Identifier: (BSD-3-Clause OR GPL-2.0-only)
7 */
8
9 /******************************************************************************/
10 /* File includes */
11 /* */
12 #include <wsutil/pint.h>
13 #include <wsutil/crc32.h>
14 #include "dot11decrypt_system.h"
15 #include "dot11decrypt_int.h"
16
17 #include "dot11decrypt_debug.h"
18 /* */
19 /******************************************************************************/
20
21 /******************************************************************************/
22 /* Internal definitions */
23 /* */
24 #define PHASE1_LOOP_COUNT 8
25
26 #define DOT11DECRYPT_TTAK_LEN 6
27 /* */
28 /******************************************************************************/
29
30 /******************************************************************************/
31 /* Internal function prototypes declarations */
32 /* */
33 static void Dot11DecryptTkipMixingPhase1(
34 UINT16 *TTAK,
35 const UINT8 *TK,
36 const UINT8 *TA,
37 UINT32 TSC)
38 ;
39
40 static void Dot11DecryptTkipMixingPhase2(
41 UINT8 *wep_seed,
42 const UINT8 *TK,
43 UINT16 *PPK,
44 UINT16 TSC16)
45 ;
46
47 /* */
48 /******************************************************************************/
49
50 /******************************************************************************/
51 /* Global variables */
52 /* */
53 /* Note: copied from FreeBSD source code, RELENG 6, */
54 /* sys/net80211/ieee80211_crypto_tkip.c, 471 */
55 static const UINT16 Sbox[256] = {
56 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
57 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
58 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
59 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
60 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
61 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
62 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
63 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
64 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
65 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
66 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
67 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
68 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
69 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
70 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
71 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
72 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
73 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
74 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
75 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
76 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
77 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
78 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
79 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
80 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
81 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
82 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
83 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
84 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
85 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
86 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
87 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
88 };
89 /* */
90 /******************************************************************************/
91
92 /* TODO: check for little-endian, big-endian */
93
94 /* */
95 /* Note: any functions were copied from FreeBSD source code, RELENG 6, */
96 /* sys/net80211/ieee80211_crypto_tkip.c */
97 /* Converted to macros to avoid using __inline, as not all compilers support it */
98 #define RotR1(val) ((UINT16)(((val) >> 1) | ((val) << 15)))
99
100 #define Lo8(val) ((UINT8)((val) & 0xff))
101
102 #define Hi8(val) ((UINT8)((val) >> 8))
103
104 #define Lo16(val) ((UINT16)((val) & 0xffff))
105
106 #define Hi16(val) ((UINT16)((val) >> 16))
107
108 #define Mk16(hi, lo) \
109 ((UINT16)((lo) | (((UINT16) (hi)) << 8)))
110
111 #define Mk16_le(v) ((UINT16)pletoh16(v))
112
113 #define _S_(v) \
114 ((UINT16)(Sbox[Lo8(v)] ^ ((Sbox[Hi8(v)] << 8) | (Sbox[Hi8(v)] >> 8))))
115
116 #define READ_6(b0, b1, b2, b3, b4, b5) \
117 ((((UINT64)((UINT16)((b4 << 0) | (b5 << 8)))) << 32) | \
118 ((UINT32)((b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24))))
119
120 /******************************************************************************/
121 /* Function definitions */
122
Dot11DecryptTkipMixingPhase1(UINT16 * TTAK,const UINT8 * TK,const UINT8 * TA,UINT32 TSC)123 static void Dot11DecryptTkipMixingPhase1(
124 UINT16 *TTAK,
125 const UINT8 *TK,
126 const UINT8 *TA,
127 UINT32 TSC)
128 {
129 UINT16 i, j;
130
131 /* Initialize the 80-bit TTAK from TSC (TSC) and TA[0..5] */
132 TTAK[0] = Lo16(TSC);
133 TTAK[1] = Hi16(TSC);
134 TTAK[2] = Mk16(TA[1], TA[0]);
135 TTAK[3] = Mk16(TA[3], TA[2]);
136 TTAK[4] = Mk16(TA[5], TA[4]);
137
138 for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
139 j = (UINT16)(2 * (i & 1));
140 TTAK[0] = (UINT16)(TTAK[0] + _S_((UINT16)(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]))));
141 TTAK[1] = (UINT16)(TTAK[1] + _S_((UINT16)(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]))));
142 TTAK[2] = (UINT16)(TTAK[2] + _S_((UINT16)(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]))));
143 TTAK[3] = (UINT16)(TTAK[3] + _S_((UINT16)(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]))));
144 TTAK[4] = (UINT16)(TTAK[4] + _S_((UINT16)(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j]))) + i);
145 }
146 }
147
Dot11DecryptTkipMixingPhase2(UINT8 * wep_seed,const UINT8 * TK,UINT16 * TTAK,UINT16 TSC16)148 static void Dot11DecryptTkipMixingPhase2(
149 UINT8 *wep_seed,
150 const UINT8 *TK,
151 UINT16 *TTAK,
152 UINT16 TSC16)
153 {
154 INT i;
155 TTAK[5] = (UINT16)(TTAK[4] + TSC16);
156
157 /* Step 2 - 96-bit bijective mixing using S-box */
158 TTAK[0] = (UINT16)(TTAK[0] + _S_((UINT16)(TTAK[5] ^ Mk16_le(&TK[0]))));
159 TTAK[1] = (UINT16)(TTAK[1] + _S_((UINT16)(TTAK[0] ^ Mk16_le(&TK[2]))));
160 TTAK[2] = (UINT16)(TTAK[2] + _S_((UINT16)(TTAK[1] ^ Mk16_le(&TK[4]))));
161 TTAK[3] = (UINT16)(TTAK[3] + _S_((UINT16)(TTAK[2] ^ Mk16_le(&TK[6]))));
162 TTAK[4] = (UINT16)(TTAK[4] + _S_((UINT16)(TTAK[3] ^ Mk16_le(&TK[8]))));
163 TTAK[5] = (UINT16)(TTAK[5] + _S_((UINT16)(TTAK[4] ^ Mk16_le(&TK[10]))));
164
165 TTAK[0] = (UINT16)(TTAK[0] + RotR1((UINT16)(TTAK[5] ^ Mk16_le(&TK[12]))));
166 TTAK[1] = (UINT16)(TTAK[1] + RotR1((UINT16)(TTAK[0] ^ Mk16_le(&TK[14]))));
167 TTAK[2] = (UINT16)(TTAK[2] + RotR1(TTAK[1]));
168 TTAK[3] = (UINT16)(TTAK[3] + RotR1(TTAK[2]));
169 TTAK[4] = (UINT16)(TTAK[4] + RotR1(TTAK[3]));
170 TTAK[5] = (UINT16)(TTAK[5] + RotR1(TTAK[4]));
171
172 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
173 * wep_seed[0..2] is transmitted as WEP IV */
174 wep_seed[0] = Hi8(TSC16);
175 wep_seed[1] = (UINT8)((Hi8(TSC16) | 0x20) & 0x7F);
176 wep_seed[2] = Lo8(TSC16);
177 wep_seed[3] = Lo8((UINT16)((TTAK[5] ^ Mk16_le(&TK[0])) >> 1));
178
179 for (i = 0; i < 6; i++)
180 {
181 wep_seed[4 + ( 2 * i)] = Lo8( TTAK[i] );
182 wep_seed[5 + ( 2 * i)] = Hi8( TTAK[i] );
183 }
184 }
185
186 /* Note: taken from FreeBSD source code, RELENG 6, */
187 /* sys/net80211/ieee80211_crypto_tkip.c, 936 */
Dot11DecryptTkipDecrypt(UCHAR * tkip_mpdu,size_t mpdu_len,UCHAR TA[DOT11DECRYPT_MAC_LEN],UCHAR TK[DOT11DECRYPT_TK_LEN])188 INT Dot11DecryptTkipDecrypt(
189 UCHAR *tkip_mpdu,
190 size_t mpdu_len,
191 UCHAR TA[DOT11DECRYPT_MAC_LEN],
192 UCHAR TK[DOT11DECRYPT_TK_LEN])
193 {
194 UINT64 TSC64;
195 UINT32 TSC;
196 UINT16 TSC16;
197 UINT8 *IV;
198 UINT16 TTAK[DOT11DECRYPT_TTAK_LEN];
199 UINT8 wep_seed[DOT11DECRYPT_WEP_128_KEY_LEN];
200
201 IV = tkip_mpdu;
202
203 TSC64 = READ_6(IV[2], IV[0], IV[4], IV[5], IV[6], IV[7]);
204 TSC16 = (UINT16)TSC64;
205
206 /* The original code made no sense!! We were shifting a 16-bit number 16 bits to the right. */
207 /* We instead have to have READ_6() be returned to a UINT64 and shift *that* value. */
208 TSC = (UINT32)(TSC64 >> 16);
209
210 Dot11DecryptTkipMixingPhase1(TTAK, TK, TA, TSC);
211
212 Dot11DecryptTkipMixingPhase2(wep_seed, TK, TTAK, TSC16);
213
214 return Dot11DecryptWepDecrypt(
215 wep_seed,
216 DOT11DECRYPT_WEP_128_KEY_LEN,
217 tkip_mpdu + DOT11DECRYPT_TKIP_HEADER,
218 mpdu_len-(DOT11DECRYPT_TKIP_HEADER+DOT11DECRYPT_WEP_ICV)); /* MPDU - TKIP_HEADER - MIC */
219
220 /* TODO check (IEEE 802.11i-2004, pg. 44) */
221
222 }
223 /* */
224 /******************************************************************************/
225