diff options
Diffstat (limited to 'drivers/staging/ks7010/michael_mic.c')
-rw-r--r-- | drivers/staging/ks7010/michael_mic.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/drivers/staging/ks7010/michael_mic.c b/drivers/staging/ks7010/michael_mic.c new file mode 100644 index 0000000..e14c109 --- /dev/null +++ b/drivers/staging/ks7010/michael_mic.c @@ -0,0 +1,139 @@ +/* + * Driver for KeyStream wireless LAN + * + * Copyright (C) 2005-2008 KeyStream Corp. + * Copyright (C) 2009 Renesas Technology Corp. + * + * 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. + */ + +#include <linux/types.h> +#include <linux/string.h> +#include "michael_mic.h" + +// Rotation functions on 32 bit values +#define ROL32( A, n ) ( ((A) << (n)) | ( ((A)>>(32-(n))) & ( (1UL << (n)) - 1 ) ) ) +#define ROR32( A, n ) ROL32( (A), 32-(n) ) +// Convert from Byte[] to UInt32 in a portable way +#define getUInt32( A, B ) (uint32_t)(A[B+0] << 0) + (A[B+1] << 8) + (A[B+2] << 16) + (A[B+3] << 24) + +// Convert from UInt32 to Byte[] in a portable way +#define putUInt32( A, B, C ) A[B+0] = (uint8_t) (C & 0xff); \ + A[B+1] = (uint8_t) ((C>>8) & 0xff); \ + A[B+2] = (uint8_t) ((C>>16) & 0xff); \ + A[B+3] = (uint8_t) ((C>>24) & 0xff) + +// Reset the state to the empty message. +#define MichaelClear( A ) A->L = A->K0; \ + A->R = A->K1; \ + A->nBytesInM = 0; + +static +void MichaelInitializeFunction(struct michel_mic_t *Mic, uint8_t * key) +{ + // Set the key + Mic->K0 = getUInt32(key, 0); + Mic->K1 = getUInt32(key, 4); + + //clear(); + MichaelClear(Mic); +} + +#define MichaelBlockFunction(L, R) \ +do{ \ + R ^= ROL32( L, 17 ); \ + L += R; \ + R ^= ((L & 0xff00ff00) >> 8) | ((L & 0x00ff00ff) << 8); \ + L += R; \ + R ^= ROL32( L, 3 ); \ + L += R; \ + R ^= ROR32( L, 2 ); \ + L += R; \ +}while(0) + +static +void MichaelAppend(struct michel_mic_t *Mic, uint8_t * src, int nBytes) +{ + int addlen; + if (Mic->nBytesInM) { + addlen = 4 - Mic->nBytesInM; + if (addlen > nBytes) + addlen = nBytes; + memcpy(&Mic->M[Mic->nBytesInM], src, addlen); + Mic->nBytesInM += addlen; + src += addlen; + nBytes -= addlen; + + if (Mic->nBytesInM < 4) + return; + + Mic->L ^= getUInt32(Mic->M, 0); + MichaelBlockFunction(Mic->L, Mic->R); + Mic->nBytesInM = 0; + } + + while (nBytes >= 4) { + Mic->L ^= getUInt32(src, 0); + MichaelBlockFunction(Mic->L, Mic->R); + src += 4; + nBytes -= 4; + } + + if (nBytes > 0) { + Mic->nBytesInM = nBytes; + memcpy(Mic->M, src, nBytes); + } +} + +static +void MichaelGetMIC(struct michel_mic_t *Mic, uint8_t * dst) +{ + uint8_t *data = Mic->M; + switch (Mic->nBytesInM) { + case 0: + Mic->L ^= 0x5a; + break; + case 1: + Mic->L ^= data[0] | 0x5a00; + break; + case 2: + Mic->L ^= data[0] | (data[1] << 8) | 0x5a0000; + break; + case 3: + Mic->L ^= data[0] | (data[1] << 8) | (data[2] << 16) | + 0x5a000000; + break; + } + MichaelBlockFunction(Mic->L, Mic->R); + MichaelBlockFunction(Mic->L, Mic->R); + // The appendByte function has already computed the result. + putUInt32(dst, 0, Mic->L); + putUInt32(dst, 4, Mic->R); + + // Reset to the empty message. + MichaelClear(Mic); +} + +void MichaelMICFunction(struct michel_mic_t *Mic, uint8_t * Key, + uint8_t * Data, int Len, uint8_t priority, + uint8_t * Result) +{ + uint8_t pad_data[4] = { priority, 0, 0, 0 }; + // Compute the MIC value + /* + * IEEE802.11i page 47 + * Figure 43g TKIP MIC processing format + * +--+--+--------+--+----+--+--+--+--+--+--+--+--+ + * |6 |6 |1 |3 |M |1 |1 |1 |1 |1 |1 |1 |1 | Octet + * +--+--+--------+--+----+--+--+--+--+--+--+--+--+ + * |DA|SA|Priority|0 |Data|M0|M1|M2|M3|M4|M5|M6|M7| + * +--+--+--------+--+----+--+--+--+--+--+--+--+--+ + */ + MichaelInitializeFunction(Mic, Key); + MichaelAppend(Mic, (uint8_t *) Data, 12); /* |DA|SA| */ + MichaelAppend(Mic, pad_data, 4); /* |Priority|0|0|0| */ + MichaelAppend(Mic, (uint8_t *) (Data + 12), Len - 12); /* |Data| */ + MichaelGetMIC(Mic, Result); +} |