/* * 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 <crypto/internal/skcipher.h> #include <linux/init.h> #include <linux/module.h> #include <linux/mm.h> #include <linux/string.h> #define NULL_KEY_SIZE 0 #define NULL_BLOCK_SIZE 1 #define NULL_DIGEST_SIZE 0 #define NULL_IV_SIZE 0 static int null_compress(struct crypto_tfm *tfm, 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(struct crypto_tfm *tfm) { } static void null_update(struct crypto_tfm *tfm, const u8 *data, unsigned int len) { } static void null_final(struct crypto_tfm *tfm, u8 *out) { } static int null_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) { return 0; } static void null_crypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) { memcpy(dst, src, NULL_BLOCK_SIZE); } static int skcipher_null_crypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) { struct blkcipher_walk walk; int err; blkcipher_walk_init(&walk, dst, src, nbytes); err = blkcipher_walk_virt(desc, &walk); while (walk.nbytes) { if (walk.src.virt.addr != walk.dst.virt.addr) memcpy(walk.dst.virt.addr, walk.src.virt.addr, walk.nbytes); err = blkcipher_walk_done(desc, &walk, 0); } return err; } 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_setkey = null_setkey, .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 } } }; static struct crypto_alg skcipher_null = { .cra_name = "ecb(cipher_null)", .cra_driver_name = "ecb-cipher_null", .cra_priority = 100, .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER, .cra_blocksize = NULL_BLOCK_SIZE, .cra_type = &crypto_blkcipher_type, .cra_ctxsize = 0, .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT(skcipher_null.cra_list), .cra_u = { .blkcipher = { .min_keysize = NULL_KEY_SIZE, .max_keysize = NULL_KEY_SIZE, .ivsize = NULL_IV_SIZE, .setkey = null_setkey, .encrypt = skcipher_null_crypt, .decrypt = skcipher_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(&skcipher_null); if (ret < 0) goto out_unregister_cipher; ret = crypto_register_alg(&digest_null); if (ret < 0) goto out_unregister_skcipher; ret = crypto_register_alg(&compress_null); if (ret < 0) goto out_unregister_digest; out: return ret; out_unregister_digest: crypto_unregister_alg(&digest_null); out_unregister_skcipher: crypto_unregister_alg(&skcipher_null); out_unregister_cipher: crypto_unregister_alg(&cipher_null); goto out; } static void __exit fini(void) { crypto_unregister_alg(&compress_null); crypto_unregister_alg(&digest_null); crypto_unregister_alg(&skcipher_null); crypto_unregister_alg(&cipher_null); } module_init(init); module_exit(fini); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Null Cryptographic Algorithms");