140 lines
3.3 KiB
C
140 lines
3.3 KiB
C
/*
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* Cryptographic API.
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*
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* Null algorithms, aka Much Ado About Nothing.
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*
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* These are needed for IPsec, and may be useful in general for
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* testing & debugging.
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*
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* The null cipher is compliant with RFC2410.
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*
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* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <asm/scatterlist.h>
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#include <linux/crypto.h>
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#include <linux/string.h>
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#define NULL_KEY_SIZE 0
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#define NULL_BLOCK_SIZE 1
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#define NULL_DIGEST_SIZE 0
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static int null_compress(void *ctx, const u8 *src, unsigned int slen,
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u8 *dst, unsigned int *dlen)
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{
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if (slen > *dlen)
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return -EINVAL;
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memcpy(dst, src, slen);
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*dlen = slen;
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return 0;
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}
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static void null_init(void *ctx)
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{ }
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static void null_update(void *ctx, const u8 *data, unsigned int len)
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{ }
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static void null_final(void *ctx, u8 *out)
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{ }
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static int null_setkey(void *ctx, const u8 *key,
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unsigned int keylen, u32 *flags)
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{ return 0; }
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static void null_crypt(void *ctx, u8 *dst, const u8 *src)
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{
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memcpy(dst, src, NULL_BLOCK_SIZE);
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}
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static struct crypto_alg compress_null = {
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.cra_name = "compress_null",
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.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
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.cra_blocksize = NULL_BLOCK_SIZE,
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.cra_ctxsize = 0,
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.cra_module = THIS_MODULE,
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.cra_list = LIST_HEAD_INIT(compress_null.cra_list),
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.cra_u = { .compress = {
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.coa_compress = null_compress,
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.coa_decompress = null_compress } }
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};
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static struct crypto_alg digest_null = {
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.cra_name = "digest_null",
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.cra_flags = CRYPTO_ALG_TYPE_DIGEST,
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.cra_blocksize = NULL_BLOCK_SIZE,
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.cra_ctxsize = 0,
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.cra_module = THIS_MODULE,
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.cra_list = LIST_HEAD_INIT(digest_null.cra_list),
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.cra_u = { .digest = {
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.dia_digestsize = NULL_DIGEST_SIZE,
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.dia_init = null_init,
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.dia_update = null_update,
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.dia_final = null_final } }
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};
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static struct crypto_alg cipher_null = {
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.cra_name = "cipher_null",
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.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
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.cra_blocksize = NULL_BLOCK_SIZE,
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.cra_ctxsize = 0,
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.cra_module = THIS_MODULE,
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.cra_list = LIST_HEAD_INIT(cipher_null.cra_list),
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.cra_u = { .cipher = {
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.cia_min_keysize = NULL_KEY_SIZE,
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.cia_max_keysize = NULL_KEY_SIZE,
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.cia_setkey = null_setkey,
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.cia_encrypt = null_crypt,
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.cia_decrypt = null_crypt } }
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};
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MODULE_ALIAS("compress_null");
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MODULE_ALIAS("digest_null");
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MODULE_ALIAS("cipher_null");
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static int __init init(void)
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{
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int ret = 0;
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ret = crypto_register_alg(&cipher_null);
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if (ret < 0)
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goto out;
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ret = crypto_register_alg(&digest_null);
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if (ret < 0) {
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crypto_unregister_alg(&cipher_null);
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goto out;
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}
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ret = crypto_register_alg(&compress_null);
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if (ret < 0) {
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crypto_unregister_alg(&digest_null);
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crypto_unregister_alg(&cipher_null);
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goto out;
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}
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out:
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return ret;
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}
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static void __exit fini(void)
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{
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crypto_unregister_alg(&compress_null);
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crypto_unregister_alg(&digest_null);
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crypto_unregister_alg(&cipher_null);
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}
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module_init(init);
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module_exit(fini);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Null Cryptographic Algorithms");
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