Revision 9a40ac86152c9cffd3dca482a15ddf9a8c5716b3 authored by Khem Raj on 04 June 2010, 03:05:15 UTC, committed by Russell King on 08 June 2010, 18:42:18 UTC
When functions incoming parameters are not in input operands list gcc
4.5 does not load the parameters into registers before calling this
function but the inline assembly assumes valid addresses inside this
function. This breaks the code because r0 and r1 are invalid when
execution enters v4wb_copy_user_page ()

Also the constant needs to be used as third input operand so account
for that as well.

Tested on qemu arm.

CC: <stable@kernel.org>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
1 parent 76962be
Raw File
tea.c
/* 
 * Cryptographic API.
 *
 * TEA, XTEA, and XETA crypto alogrithms
 *
 * The TEA and Xtended TEA algorithms were developed by David Wheeler 
 * and Roger Needham at the Computer Laboratory of Cambridge University.
 *
 * Due to the order of evaluation in XTEA many people have incorrectly
 * implemented it.  XETA (XTEA in the wrong order), exists for
 * compatibility with these implementations.
 *
 * Copyright (c) 2004 Aaron Grothe ajgrothe@yahoo.com
 *
 * 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.
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <asm/byteorder.h>
#include <linux/crypto.h>
#include <linux/types.h>

#define TEA_KEY_SIZE		16
#define TEA_BLOCK_SIZE		8
#define TEA_ROUNDS		32
#define TEA_DELTA		0x9e3779b9

#define XTEA_KEY_SIZE		16
#define XTEA_BLOCK_SIZE		8
#define XTEA_ROUNDS		32
#define XTEA_DELTA		0x9e3779b9

struct tea_ctx {
	u32 KEY[4];
};

struct xtea_ctx {
	u32 KEY[4];
};

static int tea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
		      unsigned int key_len)
{
	struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
	const __le32 *key = (const __le32 *)in_key;

	ctx->KEY[0] = le32_to_cpu(key[0]);
	ctx->KEY[1] = le32_to_cpu(key[1]);
	ctx->KEY[2] = le32_to_cpu(key[2]);
	ctx->KEY[3] = le32_to_cpu(key[3]);

	return 0; 

}

static void tea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	u32 y, z, n, sum = 0;
	u32 k0, k1, k2, k3;
	struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
	const __le32 *in = (const __le32 *)src;
	__le32 *out = (__le32 *)dst;

	y = le32_to_cpu(in[0]);
	z = le32_to_cpu(in[1]);

	k0 = ctx->KEY[0];
	k1 = ctx->KEY[1];
	k2 = ctx->KEY[2];
	k3 = ctx->KEY[3];

	n = TEA_ROUNDS;

	while (n-- > 0) {
		sum += TEA_DELTA;
		y += ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
		z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
	}
	
	out[0] = cpu_to_le32(y);
	out[1] = cpu_to_le32(z);
}

static void tea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	u32 y, z, n, sum;
	u32 k0, k1, k2, k3;
	struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
	const __le32 *in = (const __le32 *)src;
	__le32 *out = (__le32 *)dst;

	y = le32_to_cpu(in[0]);
	z = le32_to_cpu(in[1]);

	k0 = ctx->KEY[0];
	k1 = ctx->KEY[1];
	k2 = ctx->KEY[2];
	k3 = ctx->KEY[3];

	sum = TEA_DELTA << 5;

	n = TEA_ROUNDS;

	while (n-- > 0) {
		z -= ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
		y -= ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
		sum -= TEA_DELTA;
	}
	
	out[0] = cpu_to_le32(y);
	out[1] = cpu_to_le32(z);
}

static int xtea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
		       unsigned int key_len)
{
	struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
	const __le32 *key = (const __le32 *)in_key;

	ctx->KEY[0] = le32_to_cpu(key[0]);
	ctx->KEY[1] = le32_to_cpu(key[1]);
	ctx->KEY[2] = le32_to_cpu(key[2]);
	ctx->KEY[3] = le32_to_cpu(key[3]);

	return 0; 

}

static void xtea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	u32 y, z, sum = 0;
	u32 limit = XTEA_DELTA * XTEA_ROUNDS;
	struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
	const __le32 *in = (const __le32 *)src;
	__le32 *out = (__le32 *)dst;

	y = le32_to_cpu(in[0]);
	z = le32_to_cpu(in[1]);

	while (sum != limit) {
		y += ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum&3]); 
		sum += XTEA_DELTA;
		z += ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 &3]); 
	}
	
	out[0] = cpu_to_le32(y);
	out[1] = cpu_to_le32(z);
}

static void xtea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	u32 y, z, sum;
	struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
	const __le32 *in = (const __le32 *)src;
	__le32 *out = (__le32 *)dst;

	y = le32_to_cpu(in[0]);
	z = le32_to_cpu(in[1]);

	sum = XTEA_DELTA * XTEA_ROUNDS;

	while (sum) {
		z -= ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 & 3]);
		sum -= XTEA_DELTA;
		y -= ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum & 3]);
	}
	
	out[0] = cpu_to_le32(y);
	out[1] = cpu_to_le32(z);
}


static void xeta_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	u32 y, z, sum = 0;
	u32 limit = XTEA_DELTA * XTEA_ROUNDS;
	struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
	const __le32 *in = (const __le32 *)src;
	__le32 *out = (__le32 *)dst;

	y = le32_to_cpu(in[0]);
	z = le32_to_cpu(in[1]);

	while (sum != limit) {
		y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3];
		sum += XTEA_DELTA;
		z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3];
	}
	
	out[0] = cpu_to_le32(y);
	out[1] = cpu_to_le32(z);
}

static void xeta_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	u32 y, z, sum;
	struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
	const __le32 *in = (const __le32 *)src;
	__le32 *out = (__le32 *)dst;

	y = le32_to_cpu(in[0]);
	z = le32_to_cpu(in[1]);

	sum = XTEA_DELTA * XTEA_ROUNDS;

	while (sum) {
		z -= (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 & 3];
		sum -= XTEA_DELTA;
		y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3];
	}
	
	out[0] = cpu_to_le32(y);
	out[1] = cpu_to_le32(z);
}

static struct crypto_alg tea_alg = {
	.cra_name		=	"tea",
	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize		=	TEA_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof (struct tea_ctx),
	.cra_alignmask		=	3,
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(tea_alg.cra_list),
	.cra_u			=	{ .cipher = {
	.cia_min_keysize	=	TEA_KEY_SIZE,
	.cia_max_keysize	=	TEA_KEY_SIZE,
	.cia_setkey		= 	tea_setkey,
	.cia_encrypt		=	tea_encrypt,
	.cia_decrypt		=	tea_decrypt } }
};

static struct crypto_alg xtea_alg = {
	.cra_name		=	"xtea",
	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize		=	XTEA_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof (struct xtea_ctx),
	.cra_alignmask		=	3,
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(xtea_alg.cra_list),
	.cra_u			=	{ .cipher = {
	.cia_min_keysize	=	XTEA_KEY_SIZE,
	.cia_max_keysize	=	XTEA_KEY_SIZE,
	.cia_setkey		= 	xtea_setkey,
	.cia_encrypt		=	xtea_encrypt,
	.cia_decrypt		=	xtea_decrypt } }
};

static struct crypto_alg xeta_alg = {
	.cra_name		=	"xeta",
	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize		=	XTEA_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof (struct xtea_ctx),
	.cra_alignmask		=	3,
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(xtea_alg.cra_list),
	.cra_u			=	{ .cipher = {
	.cia_min_keysize	=	XTEA_KEY_SIZE,
	.cia_max_keysize	=	XTEA_KEY_SIZE,
	.cia_setkey		= 	xtea_setkey,
	.cia_encrypt		=	xeta_encrypt,
	.cia_decrypt		=	xeta_decrypt } }
};

static int __init tea_mod_init(void)
{
	int ret = 0;
	
	ret = crypto_register_alg(&tea_alg);
	if (ret < 0)
		goto out;

	ret = crypto_register_alg(&xtea_alg);
	if (ret < 0) {
		crypto_unregister_alg(&tea_alg);
		goto out;
	}

	ret = crypto_register_alg(&xeta_alg);
	if (ret < 0) {
		crypto_unregister_alg(&tea_alg);
		crypto_unregister_alg(&xtea_alg);
		goto out;
	}

out:	
	return ret;
}

static void __exit tea_mod_fini(void)
{
	crypto_unregister_alg(&tea_alg);
	crypto_unregister_alg(&xtea_alg);
	crypto_unregister_alg(&xeta_alg);
}

MODULE_ALIAS("xtea");
MODULE_ALIAS("xeta");

module_init(tea_mod_init);
module_exit(tea_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms");
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