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/*
* Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
* Copyright (c) 2006 CACE Technologies, Davis (California)
* All rights reserved.
*
* SPDX-License-Identifier: (BSD-3-Clause OR GPL-2.0-only)
*/
/******************************************************************************/
/* File includes */
/* */
#include <wsutil/pint.h>
#include <wsutil/crc32.h>
#include "dot11decrypt_system.h"
#include "dot11decrypt_int.h"
#include "dot11decrypt_debug.h"
/* */
/******************************************************************************/
/******************************************************************************/
/* Internal definitions */
/* */
#define PHASE1_LOOP_COUNT 8
#define DOT11DECRYPT_TTAK_LEN 6
/* */
/******************************************************************************/
/******************************************************************************/
/* Internal function prototypes declarations */
/* */
static void Dot11DecryptTkipMixingPhase1(
uint16_t *TTAK,
const uint8_t *TK,
const uint8_t *TA,
uint32_t TSC)
;
static void Dot11DecryptTkipMixingPhase2(
uint8_t *wep_seed,
const uint8_t *TK,
uint16_t *PPK,
uint16_t TSC16)
;
/* */
/******************************************************************************/
/******************************************************************************/
/* Global variables */
/* */
/* Note: copied from FreeBSD source code, RELENG 6, */
/* sys/net80211/ieee80211_crypto_tkip.c, 471 */
static const uint16_t 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,
};
/* */
/******************************************************************************/
/* TODO: check for little-endian, big-endian */
/* */
/* Note: any functions were copied from FreeBSD source code, RELENG 6, */
/* sys/net80211/ieee80211_crypto_tkip.c */
/* Converted to macros to avoid using __inline, as not all compilers support it */
#define RotR1(val) ((uint16_t)(((val) >> 1) | ((val) << 15)))
#define Lo8(val) ((uint8_t)((val) & 0xff))
#define Hi8(val) ((uint8_t)((val) >> 8))
#define Lo16(val) ((uint16_t)((val) & 0xffff))
#define Hi16(val) ((uint16_t)((val) >> 16))
#define Mk16(hi, lo) \
((uint16_t)((lo) | (((uint16_t) (hi)) << 8)))
#define Mk16_le(v) ((uint16_t)pletoh16(v))
#define _S_(v) \
((uint16_t)(Sbox[Lo8(v)] ^ ((Sbox[Hi8(v)] << 8) | (Sbox[Hi8(v)] >> 8))))
#define READ_6(b0, b1, b2, b3, b4, b5) \
((((uint64_t)((uint16_t)((b4 << 0) | (b5 << 8)))) << 32) | \
((uint32_t)((b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24))))
/******************************************************************************/
/* Function definitions */
static void Dot11DecryptTkipMixingPhase1(
uint16_t *TTAK,
const uint8_t *TK,
const uint8_t *TA,
uint32_t TSC)
{
uint16_t i, j;
/* Initialize the 80-bit TTAK from TSC (TSC) and TA[0..5] */
TTAK[0] = Lo16(TSC);
TTAK[1] = Hi16(TSC);
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 = (uint16_t)(2 * (i & 1));
TTAK[0] = (uint16_t)(TTAK[0] + _S_((uint16_t)(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]))));
TTAK[1] = (uint16_t)(TTAK[1] + _S_((uint16_t)(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]))));
TTAK[2] = (uint16_t)(TTAK[2] + _S_((uint16_t)(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]))));
TTAK[3] = (uint16_t)(TTAK[3] + _S_((uint16_t)(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]))));
TTAK[4] = (uint16_t)(TTAK[4] + _S_((uint16_t)(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j]))) + i);
}
}
static void Dot11DecryptTkipMixingPhase2(
uint8_t *wep_seed,
const uint8_t *TK,
uint16_t *TTAK,
uint16_t TSC16)
{
int i;
TTAK[5] = (uint16_t)(TTAK[4] + TSC16);
/* Step 2 - 96-bit bijective mixing using S-box */
TTAK[0] = (uint16_t)(TTAK[0] + _S_((uint16_t)(TTAK[5] ^ Mk16_le(&TK[0]))));
TTAK[1] = (uint16_t)(TTAK[1] + _S_((uint16_t)(TTAK[0] ^ Mk16_le(&TK[2]))));
TTAK[2] = (uint16_t)(TTAK[2] + _S_((uint16_t)(TTAK[1] ^ Mk16_le(&TK[4]))));
TTAK[3] = (uint16_t)(TTAK[3] + _S_((uint16_t)(TTAK[2] ^ Mk16_le(&TK[6]))));
TTAK[4] = (uint16_t)(TTAK[4] + _S_((uint16_t)(TTAK[3] ^ Mk16_le(&TK[8]))));
TTAK[5] = (uint16_t)(TTAK[5] + _S_((uint16_t)(TTAK[4] ^ Mk16_le(&TK[10]))));
TTAK[0] = (uint16_t)(TTAK[0] + RotR1((uint16_t)(TTAK[5] ^ Mk16_le(&TK[12]))));
TTAK[1] = (uint16_t)(TTAK[1] + RotR1((uint16_t)(TTAK[0] ^ Mk16_le(&TK[14]))));
TTAK[2] = (uint16_t)(TTAK[2] + RotR1(TTAK[1]));
TTAK[3] = (uint16_t)(TTAK[3] + RotR1(TTAK[2]));
TTAK[4] = (uint16_t)(TTAK[4] + RotR1(TTAK[3]));
TTAK[5] = (uint16_t)(TTAK[5] + RotR1(TTAK[4]));
/* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
* wep_seed[0..2] is transmitted as WEP IV */
wep_seed[0] = Hi8(TSC16);
wep_seed[1] = (uint8_t)((Hi8(TSC16) | 0x20) & 0x7F);
wep_seed[2] = Lo8(TSC16);
wep_seed[3] = Lo8((uint16_t)((TTAK[5] ^ Mk16_le(&TK[0])) >> 1));
for (i = 0; i < 6; i++)
{
wep_seed[4 + ( 2 * i)] = Lo8( TTAK[i] );
wep_seed[5 + ( 2 * i)] = Hi8( TTAK[i] );
}
}
/* Note: taken from FreeBSD source code, RELENG 6, */
/* sys/net80211/ieee80211_crypto_tkip.c, 936 */
int Dot11DecryptTkipDecrypt(
unsigned char *tkip_mpdu,
size_t mpdu_len,
unsigned char TA[DOT11DECRYPT_MAC_LEN],
unsigned char TK[DOT11DECRYPT_TK_LEN])
{
uint64_t TSC64;
uint32_t TSC;
uint16_t TSC16;
uint8_t *IV;
uint16_t TTAK[DOT11DECRYPT_TTAK_LEN];
uint8_t wep_seed[DOT11DECRYPT_WEP_128_KEY_LEN];
IV = tkip_mpdu;
TSC64 = READ_6(IV[2], IV[0], IV[4], IV[5], IV[6], IV[7]);
TSC16 = (uint16_t)TSC64;
/* The original code made no sense!! We were shifting a 16-bit number 16 bits to the right. */
/* We instead have to have READ_6() be returned to a uint64_t and shift *that* value. */
TSC = (uint32_t)(TSC64 >> 16);
Dot11DecryptTkipMixingPhase1(TTAK, TK, TA, TSC);
Dot11DecryptTkipMixingPhase2(wep_seed, TK, TTAK, TSC16);
return Dot11DecryptWepDecrypt(
wep_seed,
DOT11DECRYPT_WEP_128_KEY_LEN,
tkip_mpdu + DOT11DECRYPT_TKIP_HEADER,
mpdu_len-(DOT11DECRYPT_TKIP_HEADER+DOT11DECRYPT_WEP_ICV)); /* MPDU - TKIP_HEADER - MIC */
/* TODO check (IEEE 802.11i-2004, pg. 44) */
}
/* */
/******************************************************************************/
|
