Revision ac34ebb3a67e699edcb5ac72f19d31679369dfaa authored by Christopher Yeoh on 31 May 2012, 23:26:42 UTC, committed by Linus Torvalds on 01 June 2012, 00:49:32 UTC
A cleanup of rw_copy_check_uvector and compat_rw_copy_check_uvector after
changes made to support CMA in an earlier patch.

Rather than having an additional check_access parameter to these
functions, the first paramater type is overloaded to allow the caller to
specify CHECK_IOVEC_ONLY which means check that the contents of the iovec
are valid, but do not check the memory that they point to.  This is used
by process_vm_readv/writev where we need to validate that a iovec passed
to the syscall is valid but do not want to check the memory that it points
to at this point because it refers to an address space in another process.

Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent ee62c6b
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");
back to top