arch/s390/crypto/aes_s390.c

   1 /*
   2  * Cryptographic API.
   3  *
   4  * s390 implementation of the AES Cipher Algorithm.
   5  *
   6  * s390 Version:
   7  *   Copyright (C) 2005 IBM Deutschland GmbH, IBM Corporation
   8  *   Author(s): Jan Glauber (jang@de.ibm.com)
   9  *
  10  * Derived from "crypto/aes.c"
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the Free
  14  * Software Foundation; either version 2 of the License, or (at your option)
  15  * any later version.
  16  *
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/crypto.h>
  22 #include "crypt_s390.h"
  23
  24 #define AES_MIN_KEY_SIZE        16
  25 #define AES_MAX_KEY_SIZE        32
  26
  27 /* data block size for all key lengths */
  28 #define AES_BLOCK_SIZE          16
  29
  30 int has_aes_128 = 0;
  31 int has_aes_192 = 0;
  32 int has_aes_256 = 0;
  33
  34 struct s390_aes_ctx {
  35         u8 iv[AES_BLOCK_SIZE];
  36         u8 key[AES_MAX_KEY_SIZE];
  37         int key_len;
  38 };
  39
  40 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
  41                        unsigned int key_len, u32 *flags)
  42 {
  43         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
  44
  45         switch (key_len) {
  46         case 16:
  47                 if (!has_aes_128)
  48                         goto fail;
  49                 break;
  50         case 24:
  51                 if (!has_aes_192)
  52                         goto fail;
  53
  54                 break;
  55         case 32:
  56                 if (!has_aes_256)
  57                         goto fail;
  58                 break;
  59         default:
  60                 /* invalid key length */
  61                 goto fail;
  62                 break;
  63         }
  64
  65         sctx->key_len = key_len;
  66         memcpy(sctx->key, in_key, key_len);
  67         return 0;
  68 fail:
  69         *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
  70         return -EINVAL;
  71 }
  72
  73 static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  74 {
  75         const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
  76
  77         switch (sctx->key_len) {
  78         case 16:
  79                 crypt_s390_km(KM_AES_128_ENCRYPT, &sctx->key, out, in,
  80                               AES_BLOCK_SIZE);
  81                 break;
  82         case 24:
  83                 crypt_s390_km(KM_AES_192_ENCRYPT, &sctx->key, out, in,
  84                               AES_BLOCK_SIZE);
  85                 break;
  86         case 32:
  87                 crypt_s390_km(KM_AES_256_ENCRYPT, &sctx->key, out, in,
  88                               AES_BLOCK_SIZE);
  89                 break;
  90         }
  91 }
  92
  93 static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  94 {
  95         const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
  96
  97         switch (sctx->key_len) {
  98         case 16:
  99                 crypt_s390_km(KM_AES_128_DECRYPT, &sctx->key, out, in,
 100                               AES_BLOCK_SIZE);
 101                 break;
 102         case 24:
 103                 crypt_s390_km(KM_AES_192_DECRYPT, &sctx->key, out, in,
 104                               AES_BLOCK_SIZE);
 105                 break;
 106         case 32:
 107                 crypt_s390_km(KM_AES_256_DECRYPT, &sctx->key, out, in,
 108                               AES_BLOCK_SIZE);
 109                 break;
 110         }
 111 }
 112
 113 static unsigned int aes_encrypt_ecb(const struct cipher_desc *desc, u8 *out,
 114                                     const u8 *in, unsigned int nbytes)
 115 {
 116         struct s390_aes_ctx *sctx = crypto_tfm_ctx(desc->tfm);
 117         int ret;
 118
 119         /* only use complete blocks */
 120         nbytes &= ~(AES_BLOCK_SIZE - 1);
 121
 122         switch (sctx->key_len) {
 123         case 16:
 124                 ret = crypt_s390_km(KM_AES_128_ENCRYPT, &sctx->key, out, in, nbytes);
 125                 BUG_ON((ret < 0) || (ret != nbytes));
 126                 break;
 127         case 24:
 128                 ret = crypt_s390_km(KM_AES_192_ENCRYPT, &sctx->key, out, in, nbytes);
 129                 BUG_ON((ret < 0) || (ret != nbytes));
 130                 break;
 131         case 32:
 132                 ret = crypt_s390_km(KM_AES_256_ENCRYPT, &sctx->key, out, in, nbytes);
 133                 BUG_ON((ret < 0) || (ret != nbytes));
 134                 break;
 135         }
 136         return nbytes;
 137 }
 138
 139 static unsigned int aes_decrypt_ecb(const struct cipher_desc *desc, u8 *out,
 140                                     const u8 *in, unsigned int nbytes)
 141 {
 142         struct s390_aes_ctx *sctx = crypto_tfm_ctx(desc->tfm);
 143         int ret;
 144
 145         /* only use complete blocks */
 146         nbytes &= ~(AES_BLOCK_SIZE - 1);
 147
 148         switch (sctx->key_len) {
 149         case 16:
 150                 ret = crypt_s390_km(KM_AES_128_DECRYPT, &sctx->key, out, in, nbytes);
 151                 BUG_ON((ret < 0) || (ret != nbytes));
 152                 break;
 153         case 24:
 154                 ret = crypt_s390_km(KM_AES_192_DECRYPT, &sctx->key, out, in, nbytes);
 155                 BUG_ON((ret < 0) || (ret != nbytes));
 156                 break;
 157         case 32:
 158                 ret = crypt_s390_km(KM_AES_256_DECRYPT, &sctx->key, out, in, nbytes);
 159                 BUG_ON((ret < 0) || (ret != nbytes));
 160                 break;
 161         }
 162         return nbytes;
 163 }
 164
 165 static unsigned int aes_encrypt_cbc(const struct cipher_desc *desc, u8 *out,
 166                                     const u8 *in, unsigned int nbytes)
 167 {
 168         struct s390_aes_ctx *sctx = crypto_tfm_ctx(desc->tfm);
 169         int ret;
 170
 171         /* only use complete blocks */
 172         nbytes &= ~(AES_BLOCK_SIZE - 1);
 173
 174         memcpy(&sctx->iv, desc->info, AES_BLOCK_SIZE);
 175         switch (sctx->key_len) {
 176         case 16:
 177                 ret = crypt_s390_kmc(KMC_AES_128_ENCRYPT, &sctx->iv, out, in, nbytes);
 178                 BUG_ON((ret < 0) || (ret != nbytes));
 179                 break;
 180         case 24:
 181                 ret = crypt_s390_kmc(KMC_AES_192_ENCRYPT, &sctx->iv, out, in, nbytes);
 182                 BUG_ON((ret < 0) || (ret != nbytes));
 183                 break;
 184         case 32:
 185                 ret = crypt_s390_kmc(KMC_AES_256_ENCRYPT, &sctx->iv, out, in, nbytes);
 186                 BUG_ON((ret < 0) || (ret != nbytes));
 187                 break;
 188         }
 189         memcpy(desc->info, &sctx->iv, AES_BLOCK_SIZE);
 190
 191         return nbytes;
 192 }
 193
 194 static unsigned int aes_decrypt_cbc(const struct cipher_desc *desc, u8 *out,
 195                                     const u8 *in, unsigned int nbytes)
 196 {
 197         struct s390_aes_ctx *sctx = crypto_tfm_ctx(desc->tfm);
 198         int ret;
 199
 200         /* only use complete blocks */
 201         nbytes &= ~(AES_BLOCK_SIZE - 1);
 202
 203         memcpy(&sctx->iv, desc->info, AES_BLOCK_SIZE);
 204         switch (sctx->key_len) {
 205         case 16:
 206                 ret = crypt_s390_kmc(KMC_AES_128_DECRYPT, &sctx->iv, out, in, nbytes);
 207                 BUG_ON((ret < 0) || (ret != nbytes));
 208                 break;
 209         case 24:
 210                 ret = crypt_s390_kmc(KMC_AES_192_DECRYPT, &sctx->iv, out, in, nbytes);
 211                 BUG_ON((ret < 0) || (ret != nbytes));
 212                 break;
 213         case 32:
 214                 ret = crypt_s390_kmc(KMC_AES_256_DECRYPT, &sctx->iv, out, in, nbytes);
 215                 BUG_ON((ret < 0) || (ret != nbytes));
 216                 break;
 217         }
 218         return nbytes;
 219 }
 220
 221
 222 static struct crypto_alg aes_alg = {
 223         .cra_name               =       "aes",
 224         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
 225         .cra_blocksize          =       AES_BLOCK_SIZE,
 226         .cra_ctxsize            =       sizeof(struct s390_aes_ctx),
 227         .cra_module             =       THIS_MODULE,
 228         .cra_list               =       LIST_HEAD_INIT(aes_alg.cra_list),
 229         .cra_u                  =       {
 230                 .cipher = {
 231                         .cia_min_keysize        =       AES_MIN_KEY_SIZE,
 232                         .cia_max_keysize        =       AES_MAX_KEY_SIZE,
 233                         .cia_setkey             =       aes_set_key,
 234                         .cia_encrypt            =       aes_encrypt,
 235                         .cia_decrypt            =       aes_decrypt,
 236                         .cia_encrypt_ecb        =       aes_encrypt_ecb,
 237                         .cia_decrypt_ecb        =       aes_decrypt_ecb,
 238                         .cia_encrypt_cbc        =       aes_encrypt_cbc,
 239                         .cia_decrypt_cbc        =       aes_decrypt_cbc,
 240                 }
 241         }
 242 };
 243
 244 static int __init aes_init(void)
 245 {
 246         int ret;
 247
 248         if (crypt_s390_func_available(KM_AES_128_ENCRYPT))
 249                 has_aes_128 = 1;
 250         if (crypt_s390_func_available(KM_AES_192_ENCRYPT))
 251                 has_aes_192 = 1;
 252         if (crypt_s390_func_available(KM_AES_256_ENCRYPT))
 253                 has_aes_256 = 1;
 254
 255         if (!has_aes_128 && !has_aes_192 && !has_aes_256)
 256                 return -ENOSYS;
 257
 258         ret = crypto_register_alg(&aes_alg);
 259         if (ret != 0)
 260                 printk(KERN_INFO "crypt_s390: aes_s390 couldn't be loaded.\n");
 261         return ret;
 262 }
 263
 264 static void __exit aes_fini(void)
 265 {
 266         crypto_unregister_alg(&aes_alg);
 267 }
 268
 269 module_init(aes_init);
 270 module_exit(aes_fini);
 271
 272 MODULE_ALIAS("aes");
 273
 274 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
 275 MODULE_LICENSE("GPL");
 276