[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 <[email protected]> Signed-off-by: Herbert Xu <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
josf · May 17, 2005 · d085600 · d085600
1 parent ba32311
commit d085600
Showing 1 changed file with 15 additions and 13 deletions.
diff --git a/crypto/crypto_null.c b/crypto/crypto_null.c
@@ -21,18 +21,21 @@
 #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)
-{ return 0; }
-
-static int null_decompress(void *ctx, const u8 *src, unsigned int slen,
-                           u8 *dst, unsigned int *dlen)
-{ return 0; }
+{
+	if (slen > *dlen)
+		return -EINVAL;
+	memcpy(dst, src, slen);
+	*dlen = slen;
+	return 0;
+}
 
 static void null_init(void *ctx)
 { }
@@ -47,11 +50,10 @@ static int null_setkey(void *ctx, const u8 *key,
                        unsigned int keylen, u32 *flags)
 { return 0; }
 
-static void null_encrypt(void *ctx, u8 *dst, const u8 *src)
-{ }
-
-static void null_decrypt(void *ctx, u8 *dst, const u8 *src)
-{ }
+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",
@@ -62,7 +64,7 @@ static struct crypto_alg compress_null = {
 	.cra_list		=       LIST_HEAD_INIT(compress_null.cra_list),
 	.cra_u			=	{ .compress = {
 	.coa_compress 		=	null_compress,
-	.coa_decompress		=	null_decompress } }
+	.coa_decompress		=	null_compress } }
 };
 
 static struct crypto_alg digest_null = {
@@ -90,8 +92,8 @@ static struct crypto_alg cipher_null = {
 	.cia_min_keysize	=	NULL_KEY_SIZE,
 	.cia_max_keysize	=	NULL_KEY_SIZE,
 	.cia_setkey		= 	null_setkey,
-	.cia_encrypt		=	null_encrypt,
-	.cia_decrypt		=	null_decrypt } }
+	.cia_encrypt		=	null_crypt,
+	.cia_decrypt		=	null_crypt } }
 };
 
 MODULE_ALIAS("compress_null");