[deliverable/linux.git] / crypto / gf128mul.c

/* gf128mul.c - GF(2^128) multiplication functions
 *
 * Copyright (c) 2003, Dr Brian Gladman, Worcester, UK.
 * Copyright (c) 2006, Rik Snel <rsnel@cube.dyndns.org>
 *
 * Based on Dr Brian Gladman's (GPL'd) work published at
 * http://fp.gladman.plus.com/cryptography_technology/index.htm
 * See the original copyright notice below.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

/*
 ---------------------------------------------------------------------------
 Copyright (c) 2003, Dr Brian Gladman, Worcester, UK.   All rights reserved.

 LICENSE TERMS

 The free distribution and use of this software in both source and binary
 form is allowed (with or without changes) provided that:

   1. distributions of this source code include the above copyright
      notice, this list of conditions and the following disclaimer;

   2. distributions in binary form include the above copyright
      notice, this list of conditions and the following disclaimer
      in the documentation and/or other associated materials;

   3. the copyright holder's name is not used to endorse products
      built using this software without specific written permission.

 ALTERNATIVELY, provided that this notice is retained in full, this product
 may be distributed under the terms of the GNU General Public License (GPL),
 in which case the provisions of the GPL apply INSTEAD OF those given above.

 DISCLAIMER

 This software is provided 'as is' with no explicit or implied warranties
 in respect of its properties, including, but not limited to, correctness
 and/or fitness for purpose.
 ---------------------------------------------------------------------------
 Issue 31/01/2006

 This file provides fast multiplication in GF(128) as required by several
 cryptographic authentication modes
*/

#include <crypto/gf128mul.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

#define gf128mul_dat(q) { \
	q(0x00), q(0x01), q(0x02), q(0x03), q(0x04), q(0x05), q(0x06), q(0x07),\
	q(0x08), q(0x09), q(0x0a), q(0x0b), q(0x0c), q(0x0d), q(0x0e), q(0x0f),\
	q(0x10), q(0x11), q(0x12), q(0x13), q(0x14), q(0x15), q(0x16), q(0x17),\
	q(0x18), q(0x19), q(0x1a), q(0x1b), q(0x1c), q(0x1d), q(0x1e), q(0x1f),\
	q(0x20), q(0x21), q(0x22), q(0x23), q(0x24), q(0x25), q(0x26), q(0x27),\
	q(0x28), q(0x29), q(0x2a), q(0x2b), q(0x2c), q(0x2d), q(0x2e), q(0x2f),\
	q(0x30), q(0x31), q(0x32), q(0x33), q(0x34), q(0x35), q(0x36), q(0x37),\
	q(0x38), q(0x39), q(0x3a), q(0x3b), q(0x3c), q(0x3d), q(0x3e), q(0x3f),\
	q(0x40), q(0x41), q(0x42), q(0x43), q(0x44), q(0x45), q(0x46), q(0x47),\
	q(0x48), q(0x49), q(0x4a), q(0x4b), q(0x4c), q(0x4d), q(0x4e), q(0x4f),\
	q(0x50), q(0x51), q(0x52), q(0x53), q(0x54), q(0x55), q(0x56), q(0x57),\
	q(0x58), q(0x59), q(0x5a), q(0x5b), q(0x5c), q(0x5d), q(0x5e), q(0x5f),\
	q(0x60), q(0x61), q(0x62), q(0x63), q(0x64), q(0x65), q(0x66), q(0x67),\
	q(0x68), q(0x69), q(0x6a), q(0x6b), q(0x6c), q(0x6d), q(0x6e), q(0x6f),\
	q(0x70), q(0x71), q(0x72), q(0x73), q(0x74), q(0x75), q(0x76), q(0x77),\
	q(0x78), q(0x79), q(0x7a), q(0x7b), q(0x7c), q(0x7d), q(0x7e), q(0x7f),\
	q(0x80), q(0x81), q(0x82), q(0x83), q(0x84), q(0x85), q(0x86), q(0x87),\
	q(0x88), q(0x89), q(0x8a), q(0x8b), q(0x8c), q(0x8d), q(0x8e), q(0x8f),\
	q(0x90), q(0x91), q(0x92), q(0x93), q(0x94), q(0x95), q(0x96), q(0x97),\
	q(0x98), q(0x99), q(0x9a), q(0x9b), q(0x9c), q(0x9d), q(0x9e), q(0x9f),\
	q(0xa0), q(0xa1), q(0xa2), q(0xa3), q(0xa4), q(0xa5), q(0xa6), q(0xa7),\
	q(0xa8), q(0xa9), q(0xaa), q(0xab), q(0xac), q(0xad), q(0xae), q(0xaf),\
	q(0xb0), q(0xb1), q(0xb2), q(0xb3), q(0xb4), q(0xb5), q(0xb6), q(0xb7),\
	q(0xb8), q(0xb9), q(0xba), q(0xbb), q(0xbc), q(0xbd), q(0xbe), q(0xbf),\
	q(0xc0), q(0xc1), q(0xc2), q(0xc3), q(0xc4), q(0xc5), q(0xc6), q(0xc7),\
	q(0xc8), q(0xc9), q(0xca), q(0xcb), q(0xcc), q(0xcd), q(0xce), q(0xcf),\
	q(0xd0), q(0xd1), q(0xd2), q(0xd3), q(0xd4), q(0xd5), q(0xd6), q(0xd7),\
	q(0xd8), q(0xd9), q(0xda), q(0xdb), q(0xdc), q(0xdd), q(0xde), q(0xdf),\
	q(0xe0), q(0xe1), q(0xe2), q(0xe3), q(0xe4), q(0xe5), q(0xe6), q(0xe7),\
	q(0xe8), q(0xe9), q(0xea), q(0xeb), q(0xec), q(0xed), q(0xee), q(0xef),\
	q(0xf0), q(0xf1), q(0xf2), q(0xf3), q(0xf4), q(0xf5), q(0xf6), q(0xf7),\
	q(0xf8), q(0xf9), q(0xfa), q(0xfb), q(0xfc), q(0xfd), q(0xfe), q(0xff) \
}

/*	Given the value i in 0..255 as the byte overflow when a field element
    in GHASH is multipled by x^8, this function will return the values that
    are generated in the lo 16-bit word of the field value by applying the
    modular polynomial. The values lo_byte and hi_byte are returned via the
    macro xp_fun(lo_byte, hi_byte) so that the values can be assembled into
    memory as required by a suitable definition of this macro operating on
    the table above
*/

#define xx(p, q)	0x##p##q

#define xda_bbe(i) ( \
	(i & 0x80 ? xx(43, 80) : 0) ^ (i & 0x40 ? xx(21, c0) : 0) ^ \
	(i & 0x20 ? xx(10, e0) : 0) ^ (i & 0x10 ? xx(08, 70) : 0) ^ \
	(i & 0x08 ? xx(04, 38) : 0) ^ (i & 0x04 ? xx(02, 1c) : 0) ^ \
	(i & 0x02 ? xx(01, 0e) : 0) ^ (i & 0x01 ? xx(00, 87) : 0) \
)

#define xda_lle(i) ( \
	(i & 0x80 ? xx(e1, 00) : 0) ^ (i & 0x40 ? xx(70, 80) : 0) ^ \
	(i & 0x20 ? xx(38, 40) : 0) ^ (i & 0x10 ? xx(1c, 20) : 0) ^ \
	(i & 0x08 ? xx(0e, 10) : 0) ^ (i & 0x04 ? xx(07, 08) : 0) ^ \
	(i & 0x02 ? xx(03, 84) : 0) ^ (i & 0x01 ? xx(01, c2) : 0) \
)

static const u16 gf128mul_table_lle[256] = gf128mul_dat(xda_lle);
static const u16 gf128mul_table_bbe[256] = gf128mul_dat(xda_bbe);

/* These functions multiply a field element by x, by x^4 and by x^8
 * in the polynomial field representation. It uses 32-bit word operations
 * to gain speed but compensates for machine endianess and hence works
 * correctly on both styles of machine.
 */

static void gf128mul_x_lle(be128 *r, const be128 *x)
{
	u64 a = be64_to_cpu(x->a);
	u64 b = be64_to_cpu(x->b);
	u64 _tt = gf128mul_table_lle[(b << 7) & 0xff];

	r->b = cpu_to_be64((b >> 1) | (a << 63));
	r->a = cpu_to_be64((a >> 1) ^ (_tt << 48));
}

static void gf128mul_x_bbe(be128 *r, const be128 *x)
{
	u64 a = be64_to_cpu(x->a);
	u64 b = be64_to_cpu(x->b);
	u64 _tt = gf128mul_table_bbe[a >> 63];

	r->a = cpu_to_be64((a << 1) | (b >> 63));
	r->b = cpu_to_be64((b << 1) ^ _tt);
}

static void gf128mul_x8_lle(be128 *x)
{
	u64 a = be64_to_cpu(x->a);
	u64 b = be64_to_cpu(x->b);
	u64 _tt = gf128mul_table_lle[b & 0xff];

	x->b = cpu_to_be64((b >> 8) | (a << 56));
	x->a = cpu_to_be64((a >> 8) ^ (_tt << 48));
}

static void gf128mul_x8_bbe(be128 *x)
{
	u64 a = be64_to_cpu(x->a);
	u64 b = be64_to_cpu(x->b);
	u64 _tt = gf128mul_table_bbe[a >> 56];

	x->a = cpu_to_be64((a << 8) | (b >> 56));
	x->b = cpu_to_be64((b << 8) ^ _tt);
}

void gf128mul_lle(be128 *r, const be128 *b)
{
	be128 p[8];
	int i;

	p[0] = *r;
	for (i = 0; i < 7; ++i)
		gf128mul_x_lle(&p[i + 1], &p[i]);

	memset(r, 0, sizeof(r));
	for (i = 0;;) {
		u8 ch = ((u8 *)b)[15 - i];

		if (ch & 0x80)
			be128_xor(r, r, &p[0]);
		if (ch & 0x40)
			be128_xor(r, r, &p[1]);
		if (ch & 0x20)
			be128_xor(r, r, &p[2]);
		if (ch & 0x10)
			be128_xor(r, r, &p[3]);
		if (ch & 0x08)
			be128_xor(r, r, &p[4]);
		if (ch & 0x04)
			be128_xor(r, r, &p[5]);
		if (ch & 0x02)
			be128_xor(r, r, &p[6]);
		if (ch & 0x01)
			be128_xor(r, r, &p[7]);

		if (++i >= 16)
			break;

		gf128mul_x8_lle(r);
	}
}
EXPORT_SYMBOL(gf128mul_lle);

void gf128mul_bbe(be128 *r, const be128 *b)
{
	be128 p[8];
	int i;

	p[0] = *r;
	for (i = 0; i < 7; ++i)
		gf128mul_x_bbe(&p[i + 1], &p[i]);

	memset(r, 0, sizeof(r));
	for (i = 0;;) {
		u8 ch = ((u8 *)b)[i];

		if (ch & 0x80)
			be128_xor(r, r, &p[7]);
		if (ch & 0x40)
			be128_xor(r, r, &p[6]);
		if (ch & 0x20)
			be128_xor(r, r, &p[5]);
		if (ch & 0x10)
			be128_xor(r, r, &p[4]);
		if (ch & 0x08)
			be128_xor(r, r, &p[3]);
		if (ch & 0x04)
			be128_xor(r, r, &p[2]);
		if (ch & 0x02)
			be128_xor(r, r, &p[1]);
		if (ch & 0x01)
			be128_xor(r, r, &p[0]);

		if (++i >= 16)
			break;

		gf128mul_x8_bbe(r);
	}
}
EXPORT_SYMBOL(gf128mul_bbe);

/*      This version uses 64k bytes of table space.
    A 16 byte buffer has to be multiplied by a 16 byte key
    value in GF(128).  If we consider a GF(128) value in
    the buffer's lowest byte, we can construct a table of
    the 256 16 byte values that result from the 256 values
    of this byte.  This requires 4096 bytes. But we also
    need tables for each of the 16 higher bytes in the
    buffer as well, which makes 64 kbytes in total.
*/
/* additional explanation
 * t[0][BYTE] contains g*BYTE
 * t[1][BYTE] contains g*x^8*BYTE
 *  ..
 * t[15][BYTE] contains g*x^120*BYTE */
struct gf128mul_64k *gf128mul_init_64k_lle(const be128 *g)
{
	struct gf128mul_64k *t;
	int i, j, k;

	t = kzalloc(sizeof(*t), GFP_KERNEL);
	if (!t)
		goto out;

	for (i = 0; i < 16; i++) {
		t->t[i] = kzalloc(sizeof(*t->t[i]), GFP_KERNEL);
		if (!t->t[i]) {
			gf128mul_free_64k(t);
			t = NULL;
			goto out;
		}
	}

	t->t[0]->t[128] = *g;
	for (j = 64; j > 0; j >>= 1)
		gf128mul_x_lle(&t->t[0]->t[j], &t->t[0]->t[j + j]);

	for (i = 0;;) {
		for (j = 2; j < 256; j += j)
			for (k = 1; k < j; ++k)
				be128_xor(&t->t[i]->t[j + k],
					  &t->t[i]->t[j], &t->t[i]->t[k]);

		if (++i >= 16)
			break;

		for (j = 128; j > 0; j >>= 1) {
			t->t[i]->t[j] = t->t[i - 1]->t[j];
			gf128mul_x8_lle(&t->t[i]->t[j]);
		}
	}

out:
	return t;
}
EXPORT_SYMBOL(gf128mul_init_64k_lle);

struct gf128mul_64k *gf128mul_init_64k_bbe(const be128 *g)
{
	struct gf128mul_64k *t;
	int i, j, k;

	t = kzalloc(sizeof(*t), GFP_KERNEL);
	if (!t)
		goto out;

	for (i = 0; i < 16; i++) {
		t->t[i] = kzalloc(sizeof(*t->t[i]), GFP_KERNEL);
		if (!t->t[i]) {
			gf128mul_free_64k(t);
			t = NULL;
			goto out;
		}
	}

	t->t[0]->t[1] = *g;
	for (j = 1; j <= 64; j <<= 1)
		gf128mul_x_bbe(&t->t[0]->t[j + j], &t->t[0]->t[j]);

	for (i = 0;;) {
		for (j = 2; j < 256; j += j)
			for (k = 1; k < j; ++k)
				be128_xor(&t->t[i]->t[j + k],
					  &t->t[i]->t[j], &t->t[i]->t[k]);

		if (++i >= 16)
			break;

		for (j = 128; j > 0; j >>= 1) {
			t->t[i]->t[j] = t->t[i - 1]->t[j];
			gf128mul_x8_bbe(&t->t[i]->t[j]);
		}
	}

out:
	return t;
}
EXPORT_SYMBOL(gf128mul_init_64k_bbe);

void gf128mul_free_64k(struct gf128mul_64k *t)
{
	int i;

	for (i = 0; i < 16; i++)
		kfree(t->t[i]);
	kfree(t);
}
EXPORT_SYMBOL(gf128mul_free_64k);

void gf128mul_64k_lle(be128 *a, struct gf128mul_64k *t)
{
	u8 *ap = (u8 *)a;
	be128 r[1];
	int i;

	*r = t->t[0]->t[ap[0]];
	for (i = 1; i < 16; ++i)
		be128_xor(r, r, &t->t[i]->t[ap[i]]);
	*a = *r;
}
EXPORT_SYMBOL(gf128mul_64k_lle);

void gf128mul_64k_bbe(be128 *a, struct gf128mul_64k *t)
{
	u8 *ap = (u8 *)a;
	be128 r[1];
	int i;

	*r = t->t[0]->t[ap[15]];
	for (i = 1; i < 16; ++i)
		be128_xor(r, r, &t->t[i]->t[ap[15 - i]]);
	*a = *r;
}
EXPORT_SYMBOL(gf128mul_64k_bbe);

/*      This version uses 4k bytes of table space.
    A 16 byte buffer has to be multiplied by a 16 byte key
    value in GF(128).  If we consider a GF(128) value in a
    single byte, we can construct a table of the 256 16 byte
    values that result from the 256 values of this byte.
    This requires 4096 bytes. If we take the highest byte in
    the buffer and use this table to get the result, we then
    have to multiply by x^120 to get the final value. For the
    next highest byte the result has to be multiplied by x^112
    and so on. But we can do this by accumulating the result
    in an accumulator starting with the result for the top
    byte.  We repeatedly multiply the accumulator value by
    x^8 and then add in (i.e. xor) the 16 bytes of the next
    lower byte in the buffer, stopping when we reach the
    lowest byte. This requires a 4096 byte table.
*/
struct gf128mul_4k *gf128mul_init_4k_lle(const be128 *g)
{
	struct gf128mul_4k *t;
	int j, k;

	t = kzalloc(sizeof(*t), GFP_KERNEL);
	if (!t)
		goto out;

	t->t[128] = *g;
	for (j = 64; j > 0; j >>= 1)
		gf128mul_x_lle(&t->t[j], &t->t[j+j]);

	for (j = 2; j < 256; j += j)
		for (k = 1; k < j; ++k)
			be128_xor(&t->t[j + k], &t->t[j], &t->t[k]);

out:
	return t;
}
EXPORT_SYMBOL(gf128mul_init_4k_lle);

struct gf128mul_4k *gf128mul_init_4k_bbe(const be128 *g)
{
	struct gf128mul_4k *t;
	int j, k;

	t = kzalloc(sizeof(*t), GFP_KERNEL);
	if (!t)
		goto out;

	t->t[1] = *g;
	for (j = 1; j <= 64; j <<= 1)
		gf128mul_x_bbe(&t->t[j + j], &t->t[j]);

	for (j = 2; j < 256; j += j)
		for (k = 1; k < j; ++k)
			be128_xor(&t->t[j + k], &t->t[j], &t->t[k]);

out:
	return t;
}
EXPORT_SYMBOL(gf128mul_init_4k_bbe);

void gf128mul_4k_lle(be128 *a, struct gf128mul_4k *t)
{
	u8 *ap = (u8 *)a;
	be128 r[1];
	int i = 15;

	*r = t->t[ap[15]];
	while (i--) {
		gf128mul_x8_lle(r);
		be128_xor(r, r, &t->t[ap[i]]);
	}
	*a = *r;
}
EXPORT_SYMBOL(gf128mul_4k_lle);

void gf128mul_4k_bbe(be128 *a, struct gf128mul_4k *t)
{
	u8 *ap = (u8 *)a;
	be128 r[1];
	int i = 0;

	*r = t->t[ap[0]];
	while (++i < 16) {
		gf128mul_x8_bbe(r);
		be128_xor(r, r, &t->t[ap[i]]);
	}
	*a = *r;
}
EXPORT_SYMBOL(gf128mul_4k_bbe);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Functions for multiplying elements of GF(2^128)");
Commit	Line	Data
c494e070 RS	1	/* gf128mul.c - GF(2^128) multiplication functions
	2	*
	3	* Copyright (c) 2003, Dr Brian Gladman, Worcester, UK.
	4	* Copyright (c) 2006, Rik Snel <rsnel@cube.dyndns.org>
	5	*
	6	* Based on Dr Brian Gladman's (GPL'd) work published at
	7	* http://fp.gladman.plus.com/cryptography_technology/index.htm
	8	* See the original copyright notice below.
	9	*
	10	* This program is free software; you can redistribute it and/or modify it
	11	* under the terms of the GNU General Public License as published by the Free
	12	* Software Foundation; either version 2 of the License, or (at your option)
	13	* any later version.
	14	*/
	15
	16	/*
	17	---------------------------------------------------------------------------
	18	Copyright (c) 2003, Dr Brian Gladman, Worcester, UK. All rights reserved.
	19
	20	LICENSE TERMS
	21
	22	The free distribution and use of this software in both source and binary
	23	form is allowed (with or without changes) provided that:
	24
	25	1. distributions of this source code include the above copyright
	26	notice, this list of conditions and the following disclaimer;
	27
	28	2. distributions in binary form include the above copyright
	29	notice, this list of conditions and the following disclaimer
	30	in the documentation and/or other associated materials;
	31
	32	3. the copyright holder's name is not used to endorse products
	33	built using this software without specific written permission.
	34
	35	ALTERNATIVELY, provided that this notice is retained in full, this product
	36	may be distributed under the terms of the GNU General Public License (GPL),
	37	in which case the provisions of the GPL apply INSTEAD OF those given above.
	38
	39	DISCLAIMER
	40
	41	This software is provided 'as is' with no explicit or implied warranties
	42	in respect of its properties, including, but not limited to, correctness
	43	and/or fitness for purpose.
	44	---------------------------------------------------------------------------
	45	Issue 31/01/2006
	46
	47	This file provides fast multiplication in GF(128) as required by several
	48	cryptographic authentication modes
	49	*/
	50
	51	#include <crypto/gf128mul.h>
	52	#include <linux/kernel.h>
	53	#include <linux/module.h>
	54	#include <linux/slab.h>
	55
	56	#define gf128mul_dat(q) { \
	57	q(0x00), q(0x01), q(0x02), q(0x03), q(0x04), q(0x05), q(0x06), q(0x07),\
	58	q(0x08), q(0x09), q(0x0a), q(0x0b), q(0x0c), q(0x0d), q(0x0e), q(0x0f),\
	59	q(0x10), q(0x11), q(0x12), q(0x13), q(0x14), q(0x15), q(0x16), q(0x17),\
	60	q(0x18), q(0x19), q(0x1a), q(0x1b), q(0x1c), q(0x1d), q(0x1e), q(0x1f),\
	61	q(0x20), q(0x21), q(0x22), q(0x23), q(0x24), q(0x25), q(0x26), q(0x27),\
	62	q(0x28), q(0x29), q(0x2a), q(0x2b), q(0x2c), q(0x2d), q(0x2e), q(0x2f),\
	63	q(0x30), q(0x31), q(0x32), q(0x33), q(0x34), q(0x35), q(0x36), q(0x37),\
	64	q(0x38), q(0x39), q(0x3a), q(0x3b), q(0x3c), q(0x3d), q(0x3e), q(0x3f),\
65	q(0x40), q(0x41), q(0x42), q(0x43), q(0x44), q(0x45), q(0x46), q(0x47),\
66	q(0x48), q(0x49), q(0x4a), q(0x4b), q(0x4c), q(0x4d), q(0x4e), q(0x4f),\
67	q(0x50), q(0x51), q(0x52), q(0x53), q(0x54), q(0x55), q(0x56), q(0x57),\
68	q(0x58), q(0x59), q(0x5a), q(0x5b), q(0x5c), q(0x5d), q(0x5e), q(0x5f),\
69	q(0x60), q(0x61), q(0x62), q(0x63), q(0x64), q(0x65), q(0x66), q(0x67),\
70	q(0x68), q(0x69), q(0x6a), q(0x6b), q(0x6c), q(0x6d), q(0x6e), q(0x6f),\
71	q(0x70), q(0x71), q(0x72), q(0x73), q(0x74), q(0x75), q(0x76), q(0x77),\
72	q(0x78), q(0x79), q(0x7a), q(0x7b), q(0x7c), q(0x7d), q(0x7e), q(0x7f),\
73	q(0x80), q(0x81), q(0x82), q(0x83), q(0x84), q(0x85), q(0x86), q(0x87),\
74	q(0x88), q(0x89), q(0x8a), q(0x8b), q(0x8c), q(0x8d), q(0x8e), q(0x8f),\
75	q(0x90), q(0x91), q(0x92), q(0x93), q(0x94), q(0x95), q(0x96), q(0x97),\
76	q(0x98), q(0x99), q(0x9a), q(0x9b), q(0x9c), q(0x9d), q(0x9e), q(0x9f),\
77	q(0xa0), q(0xa1), q(0xa2), q(0xa3), q(0xa4), q(0xa5), q(0xa6), q(0xa7),\
78	q(0xa8), q(0xa9), q(0xaa), q(0xab), q(0xac), q(0xad), q(0xae), q(0xaf),\
79	q(0xb0), q(0xb1), q(0xb2), q(0xb3), q(0xb4), q(0xb5), q(0xb6), q(0xb7),\
80	q(0xb8), q(0xb9), q(0xba), q(0xbb), q(0xbc), q(0xbd), q(0xbe), q(0xbf),\
81	q(0xc0), q(0xc1), q(0xc2), q(0xc3), q(0xc4), q(0xc5), q(0xc6), q(0xc7),\
82	q(0xc8), q(0xc9), q(0xca), q(0xcb), q(0xcc), q(0xcd), q(0xce), q(0xcf),\
83	q(0xd0), q(0xd1), q(0xd2), q(0xd3), q(0xd4), q(0xd5), q(0xd6), q(0xd7),\
84	q(0xd8), q(0xd9), q(0xda), q(0xdb), q(0xdc), q(0xdd), q(0xde), q(0xdf),\
85	q(0xe0), q(0xe1), q(0xe2), q(0xe3), q(0xe4), q(0xe5), q(0xe6), q(0xe7),\
86	q(0xe8), q(0xe9), q(0xea), q(0xeb), q(0xec), q(0xed), q(0xee), q(0xef),\
87	q(0xf0), q(0xf1), q(0xf2), q(0xf3), q(0xf4), q(0xf5), q(0xf6), q(0xf7),\
88	q(0xf8), q(0xf9), q(0xfa), q(0xfb), q(0xfc), q(0xfd), q(0xfe), q(0xff) \
89	}
90
91	/* Given the value i in 0..255 as the byte overflow when a field element
92	in GHASH is multipled by x^8, this function will return the values that
93	are generated in the lo 16-bit word of the field value by applying the
94	modular polynomial. The values lo_byte and hi_byte are returned via the
95	macro xp_fun(lo_byte, hi_byte) so that the values can be assembled into
96	memory as required by a suitable definition of this macro operating on
97	the table above
98	*/
99
100	#define xx(p, q) 0x##p##q
101
102	#define xda_bbe(i) ( \
103	(i & 0x80 ? xx(43, 80) : 0) ^ (i & 0x40 ? xx(21, c0) : 0) ^ \
104	(i & 0x20 ? xx(10, e0) : 0) ^ (i & 0x10 ? xx(08, 70) : 0) ^ \
105	(i & 0x08 ? xx(04, 38) : 0) ^ (i & 0x04 ? xx(02, 1c) : 0) ^ \
106	(i & 0x02 ? xx(01, 0e) : 0) ^ (i & 0x01 ? xx(00, 87) : 0) \
107	)
108
109	#define xda_lle(i) ( \
110	(i & 0x80 ? xx(e1, 00) : 0) ^ (i & 0x40 ? xx(70, 80) : 0) ^ \
111	(i & 0x20 ? xx(38, 40) : 0) ^ (i & 0x10 ? xx(1c, 20) : 0) ^ \
112	(i & 0x08 ? xx(0e, 10) : 0) ^ (i & 0x04 ? xx(07, 08) : 0) ^ \
113	(i & 0x02 ? xx(03, 84) : 0) ^ (i & 0x01 ? xx(01, c2) : 0) \
114	)
115
116	static const u16 gf128mul_table_lle[256] = gf128mul_dat(xda_lle);
117	static const u16 gf128mul_table_bbe[256] = gf128mul_dat(xda_bbe);
118
119	/* These functions multiply a field element by x, by x^4 and by x^8
120	* in the polynomial field representation. It uses 32-bit word operations
121	* to gain speed but compensates for machine endianess and hence works
122	* correctly on both styles of machine.
123	*/
124
125	static void gf128mul_x_lle(be128 r, const be128 x)
126	{
127	u64 a = be64_to_cpu(x->a);
128	u64 b = be64_to_cpu(x->b);
129	u64 _tt = gf128mul_table_lle[(b << 7) & 0xff];
130
131	r->b = cpu_to_be64((b >> 1) \| (a << 63));
132	r->a = cpu_to_be64((a >> 1) ^ (_tt << 48));
133	}
134
135	static void gf128mul_x_bbe(be128 r, const be128 x)
136	{
137	u64 a = be64_to_cpu(x->a);
138	u64 b = be64_to_cpu(x->b);
139	u64 _tt = gf128mul_table_bbe[a >> 63];
140
141	r->a = cpu_to_be64((a << 1) \| (b >> 63));
142	r->b = cpu_to_be64((b << 1) ^ _tt);
143	}
144
145	static void gf128mul_x8_lle(be128 *x)
146	{
147	u64 a = be64_to_cpu(x->a);
148	u64 b = be64_to_cpu(x->b);
149	u64 _tt = gf128mul_table_lle[b & 0xff];
150
151	x->b = cpu_to_be64((b >> 8) \| (a << 56));
152	x->a = cpu_to_be64((a >> 8) ^ (_tt << 48));
153	}
154
155	static void gf128mul_x8_bbe(be128 *x)
156	{
157	u64 a = be64_to_cpu(x->a);
158	u64 b = be64_to_cpu(x->b);
159	u64 _tt = gf128mul_table_bbe[a >> 56];
160
161	x->a = cpu_to_be64((a << 8) \| (b >> 56));
162	x->b = cpu_to_be64((b << 8) ^ _tt);
163	}
164
165	void gf128mul_lle(be128 r, const be128 b)
166	{
167	be128 p[8];
168	int i;
169
170	p[0] = *r;
171	for (i = 0; i < 7; ++i)
172	gf128mul_x_lle(&p[i + 1], &p[i]);
173
174	memset(r, 0, sizeof(r));
175	for (i = 0;;) {
176	u8 ch = ((u8 *)b)[15 - i];
177
178	if (ch & 0x80)
179	be128_xor(r, r, &p[0]);
180	if (ch & 0x40)
181	be128_xor(r, r, &p[1]);
182	if (ch & 0x20)
183	be128_xor(r, r, &p[2]);
184	if (ch & 0x10)
185	be128_xor(r, r, &p[3]);
186	if (ch & 0x08)
187	be128_xor(r, r, &p[4]);
188	if (ch & 0x04)
189	be128_xor(r, r, &p[5]);
190	if (ch & 0x02)
191	be128_xor(r, r, &p[6]);
192	if (ch & 0x01)
193	be128_xor(r, r, &p[7]);
194
195	if (++i >= 16)
196	break;
197
198	gf128mul_x8_lle(r);
199	}
200	}
201	EXPORT_SYMBOL(gf128mul_lle);
202
203	void gf128mul_bbe(be128 r, const be128 b)
204	{
205	be128 p[8];
206	int i;
207
208	p[0] = *r;
209	for (i = 0; i < 7; ++i)
210	gf128mul_x_bbe(&p[i + 1], &p[i]);
211
212	memset(r, 0, sizeof(r));
213	for (i = 0;;) {
214	u8 ch = ((u8 *)b)[i];
215
216	if (ch & 0x80)
217	be128_xor(r, r, &p[7]);
218	if (ch & 0x40)
219	be128_xor(r, r, &p[6]);
220	if (ch & 0x20)
221	be128_xor(r, r, &p[5]);
222	if (ch & 0x10)
223	be128_xor(r, r, &p[4]);
224	if (ch & 0x08)
225	be128_xor(r, r, &p[3]);
226	if (ch & 0x04)
227	be128_xor(r, r, &p[2]);
228	if (ch & 0x02)
229	be128_xor(r, r, &p[1]);
230	if (ch & 0x01)
231	be128_xor(r, r, &p[0]);
232
233	if (++i >= 16)
234	break;
235
236	gf128mul_x8_bbe(r);
237	}
238	}
239	EXPORT_SYMBOL(gf128mul_bbe);
240
241	/* This version uses 64k bytes of table space.
242	A 16 byte buffer has to be multiplied by a 16 byte key
243	value in GF(128). If we consider a GF(128) value in
244	the buffer's lowest byte, we can construct a table of
245	the 256 16 byte values that result from the 256 values
246	of this byte. This requires 4096 bytes. But we also
247	need tables for each of the 16 higher bytes in the
248	buffer as well, which makes 64 kbytes in total.
249	*/
250	/* additional explanation
251	* t[0][BYTE] contains g*BYTE
252	* t[1][BYTE] contains gx^8BYTE
253	* ..
254	* t[15][BYTE] contains gx^120BYTE */
255	struct gf128mul_64k gf128mul_init_64k_lle(const be128 g)
256	{
257	struct gf128mul_64k *t;
258	int i, j, k;
259
260	t = kzalloc(sizeof(*t), GFP_KERNEL);
261	if (!t)
262	goto out;
263
264	for (i = 0; i < 16; i++) {
265	t->t[i] = kzalloc(sizeof(*t->t[i]), GFP_KERNEL);
266	if (!t->t[i]) {
267	gf128mul_free_64k(t);
268	t = NULL;
269	goto out;
270	}
271	}
272
273	t->t[0]->t[128] = *g;
274	for (j = 64; j > 0; j >>= 1)
275	gf128mul_x_lle(&t->t[0]->t[j], &t->t[0]->t[j + j]);
276
277	for (i = 0;;) {
278	for (j = 2; j < 256; j += j)
279	for (k = 1; k < j; ++k)
280	be128_xor(&t->t[i]->t[j + k],
281	&t->t[i]->t[j], &t->t[i]->t[k]);
282
283	if (++i >= 16)
284	break;
285
286	for (j = 128; j > 0; j >>= 1) {
287	t->t[i]->t[j] = t->t[i - 1]->t[j];
288	gf128mul_x8_lle(&t->t[i]->t[j]);
289	}
290	}
291
292	out:
293	return t;
294	}
295	EXPORT_SYMBOL(gf128mul_init_64k_lle);
296
297	struct gf128mul_64k gf128mul_init_64k_bbe(const be128 g)
298	{
299	struct gf128mul_64k *t;
300	int i, j, k;
301
302	t = kzalloc(sizeof(*t), GFP_KERNEL);
303	if (!t)
304	goto out;
305
306	for (i = 0; i < 16; i++) {
307	t->t[i] = kzalloc(sizeof(*t->t[i]), GFP_KERNEL);
308	if (!t->t[i]) {
309	gf128mul_free_64k(t);
310	t = NULL;
311	goto out;
312	}
313	}
314
315	t->t[0]->t[1] = *g;
316	for (j = 1; j <= 64; j <<= 1)
317	gf128mul_x_bbe(&t->t[0]->t[j + j], &t->t[0]->t[j]);
318
319	for (i = 0;;) {
320	for (j = 2; j < 256; j += j)
321	for (k = 1; k < j; ++k)
322	be128_xor(&t->t[i]->t[j + k],
323	&t->t[i]->t[j], &t->t[i]->t[k]);
324
325	if (++i >= 16)
326	break;
327
328	for (j = 128; j > 0; j >>= 1) {
329	t->t[i]->t[j] = t->t[i - 1]->t[j];
330	gf128mul_x8_bbe(&t->t[i]->t[j]);
331	}
332	}
333
334	out:
335	return t;
336	}
337	EXPORT_SYMBOL(gf128mul_init_64k_bbe);
338
339	void gf128mul_free_64k(struct gf128mul_64k *t)
340	{
341	int i;
342
343	for (i = 0; i < 16; i++)
344	kfree(t->t[i]);
345	kfree(t);
346	}
347	EXPORT_SYMBOL(gf128mul_free_64k);
348
349	void gf128mul_64k_lle(be128 a, struct gf128mul_64k t)
350	{
351	u8 ap = (u8 )a;
352	be128 r[1];
353	int i;
354
355	*r = t->t[0]->t[ap[0]];
356	for (i = 1; i < 16; ++i)
357	be128_xor(r, r, &t->t[i]->t[ap[i]]);
358	a = r;
359	}
360	EXPORT_SYMBOL(gf128mul_64k_lle);
361
362	void gf128mul_64k_bbe(be128 a, struct gf128mul_64k t)
363	{
364	u8 ap = (u8 )a;
365	be128 r[1];
366	int i;
367
368	*r = t->t[0]->t[ap[15]];
369	for (i = 1; i < 16; ++i)
370	be128_xor(r, r, &t->t[i]->t[ap[15 - i]]);
371	a = r;
372	}
373	EXPORT_SYMBOL(gf128mul_64k_bbe);
374
375	/* This version uses 4k bytes of table space.
376	A 16 byte buffer has to be multiplied by a 16 byte key
377	value in GF(128). If we consider a GF(128) value in a
378	single byte, we can construct a table of the 256 16 byte
379	values that result from the 256 values of this byte.
380	This requires 4096 bytes. If we take the highest byte in
381	the buffer and use this table to get the result, we then
382	have to multiply by x^120 to get the final value. For the
383	next highest byte the result has to be multiplied by x^112
384	and so on. But we can do this by accumulating the result
385	in an accumulator starting with the result for the top
386	byte. We repeatedly multiply the accumulator value by
387	x^8 and then add in (i.e. xor) the 16 bytes of the next
388	lower byte in the buffer, stopping when we reach the
389	lowest byte. This requires a 4096 byte table.
390	*/
391	struct gf128mul_4k gf128mul_init_4k_lle(const be128 g)
392	{
393	struct gf128mul_4k *t;
394	int j, k;
395
396	t = kzalloc(sizeof(*t), GFP_KERNEL);
397	if (!t)
398	goto out;
399
400	t->t[128] = *g;
401	for (j = 64; j > 0; j >>= 1)
402	gf128mul_x_lle(&t->t[j], &t->t[j+j]);
403
404	for (j = 2; j < 256; j += j)
405	for (k = 1; k < j; ++k)
406	be128_xor(&t->t[j + k], &t->t[j], &t->t[k]);
407
408	out:
409	return t;
410	}
411	EXPORT_SYMBOL(gf128mul_init_4k_lle);
412
413	struct gf128mul_4k gf128mul_init_4k_bbe(const be128 g)
414	{
415	struct gf128mul_4k *t;
416	int j, k;
417
418	t = kzalloc(sizeof(*t), GFP_KERNEL);
419	if (!t)
420	goto out;
421
422	t->t[1] = *g;
423	for (j = 1; j <= 64; j <<= 1)
424	gf128mul_x_bbe(&t->t[j + j], &t->t[j]);
425
426	for (j = 2; j < 256; j += j)
427	for (k = 1; k < j; ++k)
428	be128_xor(&t->t[j + k], &t->t[j], &t->t[k]);
429
430	out:
431	return t;
432	}
433	EXPORT_SYMBOL(gf128mul_init_4k_bbe);
434
435	void gf128mul_4k_lle(be128 a, struct gf128mul_4k t)
436	{
437	u8 ap = (u8 )a;
438	be128 r[1];
439	int i = 15;
440
441	*r = t->t[ap[15]];
442	while (i--) {
443	gf128mul_x8_lle(r);
444	be128_xor(r, r, &t->t[ap[i]]);
445	}
446	a = r;
447	}
448	EXPORT_SYMBOL(gf128mul_4k_lle);
449
450	void gf128mul_4k_bbe(be128 a, struct gf128mul_4k t)
451	{
452	u8 ap = (u8 )a;
453	be128 r[1];
454	int i = 0;
455
456	*r = t->t[ap[0]];
457	while (++i < 16) {
458	gf128mul_x8_bbe(r);
459	be128_xor(r, r, &t->t[ap[i]]);
460	}
461	a = r;
462	}
463	EXPORT_SYMBOL(gf128mul_4k_bbe);
464
465	MODULE_LICENSE("GPL");
466	MODULE_DESCRIPTION("Functions for multiplying elements of GF(2^128)");