Version:  2.6.24 2.6.25 2.6.26 2.6.27 2.6.28

Architecture:  x86 m68k m68knommu mips powerpc sh blackfin

Linux/crypto/crypto_null.c

  1 /* 
  2  * Cryptographic API.
  3  *
  4  * Null algorithms, aka Much Ado About Nothing.
  5  *
  6  * These are needed for IPsec, and may be useful in general for
  7  * testing & debugging.
  8  * 
  9  * The null cipher is compliant with RFC2410.
 10  *
 11  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 12  *
 13  * This program is free software; you can redistribute it and/or modify
 14  * it under the terms of the GNU General Public License as published by
 15  * the Free Software Foundation; either version 2 of the License, or
 16  * (at your option) any later version.
 17  *
 18  */
 19 
 20 #include <crypto/internal/skcipher.h>
 21 #include <linux/init.h>
 22 #include <linux/module.h>
 23 #include <linux/mm.h>
 24 #include <linux/string.h>
 25 
 26 #define NULL_KEY_SIZE           0
 27 #define NULL_BLOCK_SIZE         1
 28 #define NULL_DIGEST_SIZE        0
 29 #define NULL_IV_SIZE            0
 30 
 31 static int null_compress(struct crypto_tfm *tfm, const u8 *src,
 32                          unsigned int slen, u8 *dst, unsigned int *dlen)
 33 {
 34         if (slen > *dlen)
 35                 return -EINVAL;
 36         memcpy(dst, src, slen);
 37         *dlen = slen;
 38         return 0;
 39 }
 40 
 41 static void null_init(struct crypto_tfm *tfm)
 42 { }
 43 
 44 static void null_update(struct crypto_tfm *tfm, const u8 *data,
 45                         unsigned int len)
 46 { }
 47 
 48 static void null_final(struct crypto_tfm *tfm, u8 *out)
 49 { }
 50 
 51 static int null_setkey(struct crypto_tfm *tfm, const u8 *key,
 52                        unsigned int keylen)
 53 { return 0; }
 54 
 55 static void null_crypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
 56 {
 57         memcpy(dst, src, NULL_BLOCK_SIZE);
 58 }
 59 
 60 static int skcipher_null_crypt(struct blkcipher_desc *desc,
 61                                struct scatterlist *dst,
 62                                struct scatterlist *src, unsigned int nbytes)
 63 {
 64         struct blkcipher_walk walk;
 65         int err;
 66 
 67         blkcipher_walk_init(&walk, dst, src, nbytes);
 68         err = blkcipher_walk_virt(desc, &walk);
 69 
 70         while (walk.nbytes) {
 71                 if (walk.src.virt.addr != walk.dst.virt.addr)
 72                         memcpy(walk.dst.virt.addr, walk.src.virt.addr,
 73                                walk.nbytes);
 74                 err = blkcipher_walk_done(desc, &walk, 0);
 75         }
 76 
 77         return err;
 78 }
 79 
 80 static struct crypto_alg compress_null = {
 81         .cra_name               =       "compress_null",
 82         .cra_flags              =       CRYPTO_ALG_TYPE_COMPRESS,
 83         .cra_blocksize          =       NULL_BLOCK_SIZE,
 84         .cra_ctxsize            =       0,
 85         .cra_module             =       THIS_MODULE,
 86         .cra_list               =       LIST_HEAD_INIT(compress_null.cra_list),
 87         .cra_u                  =       { .compress = {
 88         .coa_compress           =       null_compress,
 89         .coa_decompress         =       null_compress } }
 90 };
 91 
 92 static struct crypto_alg digest_null = {
 93         .cra_name               =       "digest_null",
 94         .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST,
 95         .cra_blocksize          =       NULL_BLOCK_SIZE,
 96         .cra_ctxsize            =       0,
 97         .cra_module             =       THIS_MODULE,
 98         .cra_list               =       LIST_HEAD_INIT(digest_null.cra_list),   
 99         .cra_u                  =       { .digest = {
100         .dia_digestsize         =       NULL_DIGEST_SIZE,
101         .dia_setkey             =       null_setkey,
102         .dia_init               =       null_init,
103         .dia_update             =       null_update,
104         .dia_final              =       null_final } }
105 };
106 
107 static struct crypto_alg cipher_null = {
108         .cra_name               =       "cipher_null",
109         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
110         .cra_blocksize          =       NULL_BLOCK_SIZE,
111         .cra_ctxsize            =       0,
112         .cra_module             =       THIS_MODULE,
113         .cra_list               =       LIST_HEAD_INIT(cipher_null.cra_list),
114         .cra_u                  =       { .cipher = {
115         .cia_min_keysize        =       NULL_KEY_SIZE,
116         .cia_max_keysize        =       NULL_KEY_SIZE,
117         .cia_setkey             =       null_setkey,
118         .cia_encrypt            =       null_crypt,
119         .cia_decrypt            =       null_crypt } }
120 };
121 
122 static struct crypto_alg skcipher_null = {
123         .cra_name               =       "ecb(cipher_null)",
124         .cra_driver_name        =       "ecb-cipher_null",
125         .cra_priority           =       100,
126         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
127         .cra_blocksize          =       NULL_BLOCK_SIZE,
128         .cra_type               =       &crypto_blkcipher_type,
129         .cra_ctxsize            =       0,
130         .cra_module             =       THIS_MODULE,
131         .cra_list               =       LIST_HEAD_INIT(skcipher_null.cra_list),
132         .cra_u                  =       { .blkcipher = {
133         .min_keysize            =       NULL_KEY_SIZE,
134         .max_keysize            =       NULL_KEY_SIZE,
135         .ivsize                 =       NULL_IV_SIZE,
136         .setkey                 =       null_setkey,
137         .encrypt                =       skcipher_null_crypt,
138         .decrypt                =       skcipher_null_crypt } }
139 };
140 
141 MODULE_ALIAS("compress_null");
142 MODULE_ALIAS("digest_null");
143 MODULE_ALIAS("cipher_null");
144 
145 static int __init crypto_null_mod_init(void)
146 {
147         int ret = 0;
148         
149         ret = crypto_register_alg(&cipher_null);
150         if (ret < 0)
151                 goto out;
152 
153         ret = crypto_register_alg(&skcipher_null);
154         if (ret < 0)
155                 goto out_unregister_cipher;
156 
157         ret = crypto_register_alg(&digest_null);
158         if (ret < 0)
159                 goto out_unregister_skcipher;
160 
161         ret = crypto_register_alg(&compress_null);
162         if (ret < 0)
163                 goto out_unregister_digest;
164 
165 out:    
166         return ret;
167 
168 out_unregister_digest:
169         crypto_unregister_alg(&digest_null);
170 out_unregister_skcipher:
171         crypto_unregister_alg(&skcipher_null);
172 out_unregister_cipher:
173         crypto_unregister_alg(&cipher_null);
174         goto out;
175 }
176 
177 static void __exit crypto_null_mod_fini(void)
178 {
179         crypto_unregister_alg(&compress_null);
180         crypto_unregister_alg(&digest_null);
181         crypto_unregister_alg(&skcipher_null);
182         crypto_unregister_alg(&cipher_null);
183 }
184 
185 module_init(crypto_null_mod_init);
186 module_exit(crypto_null_mod_fini);
187 
188 MODULE_LICENSE("GPL");
189 MODULE_DESCRIPTION("Null Cryptographic Algorithms");
190

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