linux-hardened/crypto/crypto_null.c
Patrick McHardy d0856009db [PATCH] crypto: fix null encryption/compression
null_encrypt() needs to copy the data in case src and dst are disjunct,
null_compress() needs to copy the data in any case as far as I can tell.  I
joined compress/decompress and encrypt/decrypt to avoid duplicating code.

Without this patch ESP null_enc packets look like this:

IP (tos 0x0, ttl  64, id 23130, offset 0, flags [DF], length: 128)
10.0.0.1 > 10.0.0.2: ESP(spi=0x0f9ca149,seq=0x4)
	0x0000:  4500 0080 5a5a 4000 4032 cbef 0a00 0001  E...ZZ@.@2......
	0x0010:  0a00 0002 0f9c a149 0000 0004 0000 0000  .......I........
	0x0020:  0000 0000 0000 0000 0000 0000 0000 0000  ................
	0x0030:  0000 0000 0000 0000 0000 0000 0000 0000  ................
	0x0040:  0000 0000 0000 0000 0000 0000 0000 0000  ................
	0x0050:  0000                                     ..

IP (tos 0x0, ttl  64, id 256, offset 0, flags [DF], length: 128)
10.0.0.2 > 10.0.0.1: ESP(spi=0x0e4f7b51,seq=0x2)
	0x0000:  4500 0080 0100 4000 4032 254a 0a00 0002  E.....@.@2%J....
	0x0010:  0a00 0001 0e4f 7b51 0000 0002 a8a8 a8a8  .....O{Q........
	0x0020:  a8a8 a8a8 a8a8 a8a8 a8a8 a8a8 a8a8 a8a8  ................
	0x0030:  a8a8 a8a8 a8a8 a8a8 a8a8 a8a8 a8a8 a8a8  ................
	0x0040:  a8a8 a8a8 a8a8 a8a8 a8a8 a8a8 a8a8 a8a8  ................
	0x0050:  a8a8                                     ..

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-17 07:59:18 -07:00

139 lines
3.3 KiB
C

/*
* Cryptographic API.
*
* Null algorithms, aka Much Ado About Nothing.
*
* These are needed for IPsec, and may be useful in general for
* testing & debugging.
*
* The null cipher is compliant with RFC2410.
*
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
*
* 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/scatterlist.h>
#include <linux/crypto.h>
#include <linux/string.h>
#define NULL_KEY_SIZE 0
#define NULL_BLOCK_SIZE 1
#define NULL_DIGEST_SIZE 0
static int null_compress(void *ctx, const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen)
{
if (slen > *dlen)
return -EINVAL;
memcpy(dst, src, slen);
*dlen = slen;
return 0;
}
static void null_init(void *ctx)
{ }
static void null_update(void *ctx, const u8 *data, unsigned int len)
{ }
static void null_final(void *ctx, u8 *out)
{ }
static int null_setkey(void *ctx, const u8 *key,
unsigned int keylen, u32 *flags)
{ return 0; }
static void null_crypt(void *ctx, u8 *dst, const u8 *src)
{
memcpy(dst, src, NULL_BLOCK_SIZE);
}
static struct crypto_alg compress_null = {
.cra_name = "compress_null",
.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
.cra_blocksize = NULL_BLOCK_SIZE,
.cra_ctxsize = 0,
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(compress_null.cra_list),
.cra_u = { .compress = {
.coa_compress = null_compress,
.coa_decompress = null_compress } }
};
static struct crypto_alg digest_null = {
.cra_name = "digest_null",
.cra_flags = CRYPTO_ALG_TYPE_DIGEST,
.cra_blocksize = NULL_BLOCK_SIZE,
.cra_ctxsize = 0,
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(digest_null.cra_list),
.cra_u = { .digest = {
.dia_digestsize = NULL_DIGEST_SIZE,
.dia_init = null_init,
.dia_update = null_update,
.dia_final = null_final } }
};
static struct crypto_alg cipher_null = {
.cra_name = "cipher_null",
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = NULL_BLOCK_SIZE,
.cra_ctxsize = 0,
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(cipher_null.cra_list),
.cra_u = { .cipher = {
.cia_min_keysize = NULL_KEY_SIZE,
.cia_max_keysize = NULL_KEY_SIZE,
.cia_setkey = null_setkey,
.cia_encrypt = null_crypt,
.cia_decrypt = null_crypt } }
};
MODULE_ALIAS("compress_null");
MODULE_ALIAS("digest_null");
MODULE_ALIAS("cipher_null");
static int __init init(void)
{
int ret = 0;
ret = crypto_register_alg(&cipher_null);
if (ret < 0)
goto out;
ret = crypto_register_alg(&digest_null);
if (ret < 0) {
crypto_unregister_alg(&cipher_null);
goto out;
}
ret = crypto_register_alg(&compress_null);
if (ret < 0) {
crypto_unregister_alg(&digest_null);
crypto_unregister_alg(&cipher_null);
goto out;
}
out:
return ret;
}
static void __exit fini(void)
{
crypto_unregister_alg(&compress_null);
crypto_unregister_alg(&digest_null);
crypto_unregister_alg(&cipher_null);
}
module_init(init);
module_exit(fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Null Cryptographic Algorithms");