arch/s390/crypto/des_z990.c

   1 /*
   2  * Cryptographic API.
   3  *
   4  * z990 implementation of the DES Cipher Algorithm.
   5  *
   6  * Copyright (c) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
   7  * Author(s): Thomas Spatzier (tspat@de.ibm.com)
   8  *
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  */
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/mm.h>
  19 #include <linux/errno.h>
  20 #include <asm/scatterlist.h>
  21 #include <linux/crypto.h>
  22 #include "crypt_z990.h"
  23 #include "crypto_des.h"
  24
  25 #define DES_BLOCK_SIZE 8
  26 #define DES_KEY_SIZE 8
  27
  28 #define DES3_128_KEY_SIZE       (2 * DES_KEY_SIZE)
  29 #define DES3_128_BLOCK_SIZE     DES_BLOCK_SIZE
  30
  31 #define DES3_192_KEY_SIZE       (3 * DES_KEY_SIZE)
  32 #define DES3_192_BLOCK_SIZE     DES_BLOCK_SIZE
  33
  34 struct crypt_z990_des_ctx {
  35         u8 iv[DES_BLOCK_SIZE];
  36         u8 key[DES_KEY_SIZE];
  37 };
  38
  39 struct crypt_z990_des3_128_ctx {
  40         u8 iv[DES_BLOCK_SIZE];
  41         u8 key[DES3_128_KEY_SIZE];
  42 };
  43
  44 struct crypt_z990_des3_192_ctx {
  45         u8 iv[DES_BLOCK_SIZE];
  46         u8 key[DES3_192_KEY_SIZE];
  47 };
  48
  49 static int
  50 des_setkey(void *ctx, const u8 *key, unsigned int keylen, u32 *flags)
  51 {
  52         struct crypt_z990_des_ctx *dctx;
  53         int ret;
  54
  55         dctx = ctx;
  56         //test if key is valid (not a weak key)
  57         ret = crypto_des_check_key(key, keylen, flags);
  58         if (ret == 0){
  59                 memcpy(dctx->key, key, keylen);
  60         }
  61         return ret;
  62 }
  63
  64
  65 static void
  66 des_encrypt(void *ctx, u8 *dst, const u8 *src)
  67 {
  68         struct crypt_z990_des_ctx *dctx;
  69
  70         dctx = ctx;
  71         crypt_z990_km(KM_DEA_ENCRYPT, dctx->key, dst, src, DES_BLOCK_SIZE);
  72 }
  73
  74 static void
  75 des_decrypt(void *ctx, u8 *dst, const u8 *src)
  76 {
  77         struct crypt_z990_des_ctx *dctx;
  78
  79         dctx = ctx;
  80         crypt_z990_km(KM_DEA_DECRYPT, dctx->key, dst, src, DES_BLOCK_SIZE);
  81 }
  82
  83 static struct crypto_alg des_alg = {
  84         .cra_name               =       "des",
  85         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
  86         .cra_blocksize          =       DES_BLOCK_SIZE,
  87         .cra_ctxsize            =       sizeof(struct crypt_z990_des_ctx),
  88         .cra_module             =       THIS_MODULE,
  89         .cra_list               =       LIST_HEAD_INIT(des_alg.cra_list),
  90         .cra_u                  =       { .cipher = {
  91         .cia_min_keysize        =       DES_KEY_SIZE,
  92         .cia_max_keysize        =       DES_KEY_SIZE,
  93         .cia_setkey             =       des_setkey,
  94         .cia_encrypt            =       des_encrypt,
  95         .cia_decrypt            =       des_decrypt } }
  96 };
  97
  98 /*
  99  * RFC2451:
 100  *
 101  *   For DES-EDE3, there is no known need to reject weak or
 102  *   complementation keys.  Any weakness is obviated by the use of
 103  *   multiple keys.
 104  *
 105  *   However, if the two  independent 64-bit keys are equal,
 106  *   then the DES3 operation is simply the same as DES.
 107  *   Implementers MUST reject keys that exhibit this property.
 108  *
 109  */
 110 static int
 111 des3_128_setkey(void *ctx, const u8 *key, unsigned int keylen, u32 *flags)
 112 {
 113         int i, ret;
 114         struct crypt_z990_des3_128_ctx *dctx;
 115         const u8* temp_key = key;
 116
 117         dctx = ctx;
 118         if (!(memcmp(key, &key[DES_KEY_SIZE], DES_KEY_SIZE))) {
 119
 120                 *flags |= CRYPTO_TFM_RES_BAD_KEY_SCHED;
 121                 return -EINVAL;
 122         }
 123         for (i = 0; i < 2; i++, temp_key += DES_KEY_SIZE) {
 124                 ret = crypto_des_check_key(temp_key, DES_KEY_SIZE, flags);
 125                 if (ret < 0)
 126                         return ret;
 127         }
 128         memcpy(dctx->key, key, keylen);
 129         return 0;
 130 }
 131
 132 static void
 133 des3_128_encrypt(void *ctx, u8 *dst, const u8 *src)
 134 {
 135         struct crypt_z990_des3_128_ctx *dctx;
 136
 137         dctx = ctx;
 138         crypt_z990_km(KM_TDEA_128_ENCRYPT, dctx->key, dst, (void*)src,
 139                         DES3_128_BLOCK_SIZE);
 140 }
 141
 142 static void
 143 des3_128_decrypt(void *ctx, u8 *dst, const u8 *src)
 144 {
 145         struct crypt_z990_des3_128_ctx *dctx;
 146
 147         dctx = ctx;
 148         crypt_z990_km(KM_TDEA_128_DECRYPT, dctx->key, dst, (void*)src,
 149                         DES3_128_BLOCK_SIZE);
 150 }
 151
 152 static struct crypto_alg des3_128_alg = {
 153         .cra_name               =       "des3_ede128",
 154         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
 155         .cra_blocksize          =       DES3_128_BLOCK_SIZE,
 156         .cra_ctxsize            =       sizeof(struct crypt_z990_des3_128_ctx),
 157         .cra_module             =       THIS_MODULE,
 158         .cra_list               =       LIST_HEAD_INIT(des3_128_alg.cra_list),
 159         .cra_u                  =       { .cipher = {
 160         .cia_min_keysize        =       DES3_128_KEY_SIZE,
 161         .cia_max_keysize        =       DES3_128_KEY_SIZE,
 162         .cia_setkey             =       des3_128_setkey,
 163         .cia_encrypt            =       des3_128_encrypt,
 164         .cia_decrypt            =       des3_128_decrypt } }
 165 };
 166
 167 /*
 168  * RFC2451:
 169  *
 170  *   For DES-EDE3, there is no known need to reject weak or
 171  *   complementation keys.  Any weakness is obviated by the use of
 172  *   multiple keys.
 173  *
 174  *   However, if the first two or last two independent 64-bit keys are
 175  *   equal (k1 == k2 or k2 == k3), then the DES3 operation is simply the
 176  *   same as DES.  Implementers MUST reject keys that exhibit this
 177  *   property.
 178  *
 179  */
 180 static int
 181 des3_192_setkey(void *ctx, const u8 *key, unsigned int keylen, u32 *flags)
 182 {
 183         int i, ret;
 184         struct crypt_z990_des3_192_ctx *dctx;
 185         const u8* temp_key;
 186
 187         dctx = ctx;
 188         temp_key = key;
 189         if (!(memcmp(key, &key[DES_KEY_SIZE], DES_KEY_SIZE) &&
 190             memcmp(&key[DES_KEY_SIZE], &key[DES_KEY_SIZE * 2],
 191                                                 DES_KEY_SIZE))) {
 192
 193                 *flags |= CRYPTO_TFM_RES_BAD_KEY_SCHED;
 194                 return -EINVAL;
 195         }
 196         for (i = 0; i < 3; i++, temp_key += DES_KEY_SIZE) {
 197                 ret = crypto_des_check_key(temp_key, DES_KEY_SIZE, flags);
 198                 if (ret < 0){
 199                         return ret;
 200                 }
 201         }
 202         memcpy(dctx->key, key, keylen);
 203         return 0;
 204 }
 205
 206 static void
 207 des3_192_encrypt(void *ctx, u8 *dst, const u8 *src)
 208 {
 209         struct crypt_z990_des3_192_ctx *dctx;
 210
 211         dctx = ctx;
 212         crypt_z990_km(KM_TDEA_192_ENCRYPT, dctx->key, dst, (void*)src,
 213                         DES3_192_BLOCK_SIZE);
 214 }
 215
 216 static void
 217 des3_192_decrypt(void *ctx, u8 *dst, const u8 *src)
 218 {
 219         struct crypt_z990_des3_192_ctx *dctx;
 220
 221         dctx = ctx;
 222         crypt_z990_km(KM_TDEA_192_DECRYPT, dctx->key, dst, (void*)src,
 223                         DES3_192_BLOCK_SIZE);
 224 }
 225
 226 static struct crypto_alg des3_192_alg = {
 227         .cra_name               =       "des3_ede",
 228         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
 229         .cra_blocksize          =       DES3_192_BLOCK_SIZE,
 230         .cra_ctxsize            =       sizeof(struct crypt_z990_des3_192_ctx),
 231         .cra_module             =       THIS_MODULE,
 232         .cra_list               =       LIST_HEAD_INIT(des3_192_alg.cra_list),
 233         .cra_u                  =       { .cipher = {
 234         .cia_min_keysize        =       DES3_192_KEY_SIZE,
 235         .cia_max_keysize        =       DES3_192_KEY_SIZE,
 236         .cia_setkey             =       des3_192_setkey,
 237         .cia_encrypt            =       des3_192_encrypt,
 238         .cia_decrypt            =       des3_192_decrypt } }
 239 };
 240
 241
 242
 243 static int
 244 init(void)
 245 {
 246         int ret;
 247
 248         if (!crypt_z990_func_available(KM_DEA_ENCRYPT) ||
 249             !crypt_z990_func_available(KM_TDEA_128_ENCRYPT) ||
 250             !crypt_z990_func_available(KM_TDEA_192_ENCRYPT)){
 251                 return -ENOSYS;
 252         }
 253
 254         ret = 0;
 255         ret |= (crypto_register_alg(&des_alg) == 0)? 0:1;
 256         ret |= (crypto_register_alg(&des3_128_alg) == 0)? 0:2;
 257         ret |= (crypto_register_alg(&des3_192_alg) == 0)? 0:4;
 258         if (ret){
 259                 crypto_unregister_alg(&des3_192_alg);
 260                 crypto_unregister_alg(&des3_128_alg);
 261                 crypto_unregister_alg(&des_alg);
 262                 return -EEXIST;
 263         }
 264
 265         printk(KERN_INFO "crypt_z990: des_z990 loaded.\n");
 266         return 0;
 267 }
 268
 269 static void __exit
 270 fini(void)
 271 {
 272         crypto_unregister_alg(&des3_192_alg);
 273         crypto_unregister_alg(&des3_128_alg);
 274         crypto_unregister_alg(&des_alg);
 275 }
 276
 277 module_init(init);
 278 module_exit(fini);
 279
 280 MODULE_ALIAS("des");
 281 MODULE_ALIAS("des3_ede");
 282
 283 MODULE_LICENSE("GPL");
 284 MODULE_DESCRIPTION("DES & Triple DES EDE Cipher Algorithms");