 5d26a105b5
			
		
	
	
	5d26a105b5
	
	
	
		
			
			This prefixes all crypto module loading with "crypto-" so we never run the risk of exposing module auto-loading to userspace via a crypto API, as demonstrated by Mathias Krause: https://lkml.org/lkml/2013/3/4/70 Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
		
			
				
	
	
		
			159 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			159 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /* GPL HEADER START
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|  *
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|  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 only,
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|  * as published by the Free Software Foundation.
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|  *
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|  * This program is distributed in the hope that it will be useful, but
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|  * WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * General Public License version 2 for more details (a copy is included
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|  * in the LICENSE file that accompanied this code).
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * version 2 along with this program; If not, see http://www.gnu.org/licenses
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|  *
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|  * Please  visit http://www.xyratex.com/contact if you need additional
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|  * information or have any questions.
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|  *
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|  * GPL HEADER END
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|  */
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| 
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| /*
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|  * Copyright 2012 Xyratex Technology Limited
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|  */
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| 
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| /*
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|  * This is crypto api shash wrappers to crc32_le.
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|  */
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| 
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| #include <linux/crc32.h>
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| #include <crypto/internal/hash.h>
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| #include <linux/init.h>
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| #include <linux/module.h>
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| #include <linux/string.h>
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| #include <linux/kernel.h>
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| 
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| #define CHKSUM_BLOCK_SIZE	1
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| #define CHKSUM_DIGEST_SIZE	4
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| 
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| static u32 __crc32_le(u32 crc, unsigned char const *p, size_t len)
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| {
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| 	return crc32_le(crc, p, len);
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| }
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| 
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| /** No default init with ~0 */
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| static int crc32_cra_init(struct crypto_tfm *tfm)
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| {
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| 	u32 *key = crypto_tfm_ctx(tfm);
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| 
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| 	*key = 0;
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| 
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| 	return 0;
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| }
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| 
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| 
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| /*
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|  * Setting the seed allows arbitrary accumulators and flexible XOR policy
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|  * If your algorithm starts with ~0, then XOR with ~0 before you set
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|  * the seed.
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|  */
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| static int crc32_setkey(struct crypto_shash *hash, const u8 *key,
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| 			unsigned int keylen)
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| {
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| 	u32 *mctx = crypto_shash_ctx(hash);
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| 
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| 	if (keylen != sizeof(u32)) {
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| 		crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
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| 		return -EINVAL;
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| 	}
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| 	*mctx = le32_to_cpup((__le32 *)key);
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| 	return 0;
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| }
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| 
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| static int crc32_init(struct shash_desc *desc)
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| {
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| 	u32 *mctx = crypto_shash_ctx(desc->tfm);
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| 	u32 *crcp = shash_desc_ctx(desc);
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| 
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| 	*crcp = *mctx;
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| 
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| 	return 0;
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| }
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| 
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| static int crc32_update(struct shash_desc *desc, const u8 *data,
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| 			unsigned int len)
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| {
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| 	u32 *crcp = shash_desc_ctx(desc);
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| 
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| 	*crcp = __crc32_le(*crcp, data, len);
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| 	return 0;
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| }
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| 
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| /* No final XOR 0xFFFFFFFF, like crc32_le */
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| static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len,
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| 			 u8 *out)
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| {
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| 	*(__le32 *)out = cpu_to_le32(__crc32_le(*crcp, data, len));
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| 	return 0;
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| }
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| 
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| static int crc32_finup(struct shash_desc *desc, const u8 *data,
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| 		       unsigned int len, u8 *out)
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| {
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| 	return __crc32_finup(shash_desc_ctx(desc), data, len, out);
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| }
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| 
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| static int crc32_final(struct shash_desc *desc, u8 *out)
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| {
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| 	u32 *crcp = shash_desc_ctx(desc);
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| 
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| 	*(__le32 *)out = cpu_to_le32p(crcp);
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| 	return 0;
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| }
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| 
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| static int crc32_digest(struct shash_desc *desc, const u8 *data,
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| 			unsigned int len, u8 *out)
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| {
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| 	return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len,
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| 			     out);
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| }
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| static struct shash_alg alg = {
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| 	.setkey		= crc32_setkey,
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| 	.init		= crc32_init,
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| 	.update		= crc32_update,
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| 	.final		= crc32_final,
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| 	.finup		= crc32_finup,
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| 	.digest		= crc32_digest,
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| 	.descsize	= sizeof(u32),
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| 	.digestsize	= CHKSUM_DIGEST_SIZE,
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| 	.base		= {
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| 		.cra_name		= "crc32",
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| 		.cra_driver_name	= "crc32-table",
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| 		.cra_priority		= 100,
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| 		.cra_blocksize		= CHKSUM_BLOCK_SIZE,
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| 		.cra_ctxsize		= sizeof(u32),
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| 		.cra_module		= THIS_MODULE,
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| 		.cra_init		= crc32_cra_init,
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| 	}
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| };
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| 
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| static int __init crc32_mod_init(void)
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| {
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| 	return crypto_register_shash(&alg);
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| }
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| 
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| static void __exit crc32_mod_fini(void)
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| {
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| 	crypto_unregister_shash(&alg);
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| }
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| 
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| module_init(crc32_mod_init);
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| module_exit(crc32_mod_fini);
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| 
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| MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");
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| MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32");
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| MODULE_LICENSE("GPL");
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| MODULE_ALIAS_CRYPTO("crc32");
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