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 IBM Corp. 2005,2007
   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 <crypto/algapi.h>
  20 #include <linux/module.h>
  21 #include <linux/init.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 #define AES_KEYLEN_128          1
  31 #define AES_KEYLEN_192          2
  32 #define AES_KEYLEN_256          4
  33
  34 static char keylen_flag = 0;
  35
  36 struct s390_aes_ctx {
  37         u8 iv[AES_BLOCK_SIZE];
  38         u8 key[AES_MAX_KEY_SIZE];
  39         long enc;
  40         long dec;
  41         int key_len;
  42 };
  43
  44 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
  45                        unsigned int key_len)
  46 {
  47         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
  48         u32 *flags = &tfm->crt_flags;
  49
  50         switch (key_len) {
  51         case 16:
  52                 if (!(keylen_flag & AES_KEYLEN_128))
  53                         goto fail;
  54                 break;
  55         case 24:
  56                 if (!(keylen_flag & AES_KEYLEN_192))
  57                         goto fail;
  58
  59                 break;
  60         case 32:
  61                 if (!(keylen_flag & AES_KEYLEN_256))
  62                         goto fail;
  63                 break;
  64         default:
  65                 goto fail;
  66                 break;
  67         }
  68
  69         sctx->key_len = key_len;
  70         memcpy(sctx->key, in_key, key_len);
  71         return 0;
  72 fail:
  73         *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
  74         return -EINVAL;
  75 }
  76
  77 static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  78 {
  79         const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
  80
  81         switch (sctx->key_len) {
  82         case 16:
  83                 crypt_s390_km(KM_AES_128_ENCRYPT, &sctx->key, out, in,
  84                               AES_BLOCK_SIZE);
  85                 break;
  86         case 24:
  87                 crypt_s390_km(KM_AES_192_ENCRYPT, &sctx->key, out, in,
  88                               AES_BLOCK_SIZE);
  89                 break;
  90         case 32:
  91                 crypt_s390_km(KM_AES_256_ENCRYPT, &sctx->key, out, in,
  92                               AES_BLOCK_SIZE);
  93                 break;
  94         }
  95 }
  96
  97 static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  98 {
  99         const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 100
 101         switch (sctx->key_len) {
 102         case 16:
 103                 crypt_s390_km(KM_AES_128_DECRYPT, &sctx->key, out, in,
 104                               AES_BLOCK_SIZE);
 105                 break;
 106         case 24:
 107                 crypt_s390_km(KM_AES_192_DECRYPT, &sctx->key, out, in,
 108                               AES_BLOCK_SIZE);
 109                 break;
 110         case 32:
 111                 crypt_s390_km(KM_AES_256_DECRYPT, &sctx->key, out, in,
 112                               AES_BLOCK_SIZE);
 113                 break;
 114         }
 115 }
 116
 117
 118 static struct crypto_alg aes_alg = {
 119         .cra_name               =       "aes",
 120         .cra_driver_name        =       "aes-s390",
 121         .cra_priority           =       CRYPT_S390_PRIORITY,
 122         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
 123         .cra_blocksize          =       AES_BLOCK_SIZE,
 124         .cra_ctxsize            =       sizeof(struct s390_aes_ctx),
 125         .cra_module             =       THIS_MODULE,
 126         .cra_list               =       LIST_HEAD_INIT(aes_alg.cra_list),
 127         .cra_u                  =       {
 128                 .cipher = {
 129                         .cia_min_keysize        =       AES_MIN_KEY_SIZE,
 130                         .cia_max_keysize        =       AES_MAX_KEY_SIZE,
 131                         .cia_setkey             =       aes_set_key,
 132                         .cia_encrypt            =       aes_encrypt,
 133                         .cia_decrypt            =       aes_decrypt,
 134                 }
 135         }
 136 };
 137
 138 static int ecb_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 139                            unsigned int key_len)
 140 {
 141         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 142
 143         switch (key_len) {
 144         case 16:
 145                 sctx->enc = KM_AES_128_ENCRYPT;
 146                 sctx->dec = KM_AES_128_DECRYPT;
 147                 break;
 148         case 24:
 149                 sctx->enc = KM_AES_192_ENCRYPT;
 150                 sctx->dec = KM_AES_192_DECRYPT;
 151                 break;
 152         case 32:
 153                 sctx->enc = KM_AES_256_ENCRYPT;
 154                 sctx->dec = KM_AES_256_DECRYPT;
 155                 break;
 156         }
 157
 158         return aes_set_key(tfm, in_key, key_len);
 159 }
 160
 161 static int ecb_aes_crypt(struct blkcipher_desc *desc, long func, void *param,
 162                          struct blkcipher_walk *walk)
 163 {
 164         int ret = blkcipher_walk_virt(desc, walk);
 165         unsigned int nbytes;
 166
 167         while ((nbytes = walk->nbytes)) {
 168                 /* only use complete blocks */
 169                 unsigned int n = nbytes & ~(AES_BLOCK_SIZE - 1);
 170                 u8 *out = walk->dst.virt.addr;
 171                 u8 *in = walk->src.virt.addr;
 172
 173                 ret = crypt_s390_km(func, param, out, in, n);
 174                 BUG_ON((ret < 0) || (ret != n));
 175
 176                 nbytes &= AES_BLOCK_SIZE - 1;
 177                 ret = blkcipher_walk_done(desc, walk, nbytes);
 178         }
 179
 180         return ret;
 181 }
 182
 183 static int ecb_aes_encrypt(struct blkcipher_desc *desc,
 184                            struct scatterlist *dst, struct scatterlist *src,
 185                            unsigned int nbytes)
 186 {
 187         struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
 188         struct blkcipher_walk walk;
 189
 190         blkcipher_walk_init(&walk, dst, src, nbytes);
 191         return ecb_aes_crypt(desc, sctx->enc, sctx->key, &walk);
 192 }
 193
 194 static int ecb_aes_decrypt(struct blkcipher_desc *desc,
 195                            struct scatterlist *dst, struct scatterlist *src,
 196                            unsigned int nbytes)
 197 {
 198         struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
 199         struct blkcipher_walk walk;
 200
 201         blkcipher_walk_init(&walk, dst, src, nbytes);
 202         return ecb_aes_crypt(desc, sctx->dec, sctx->key, &walk);
 203 }
 204
 205 static struct crypto_alg ecb_aes_alg = {
 206         .cra_name               =       "ecb(aes)",
 207         .cra_driver_name        =       "ecb-aes-s390",
 208         .cra_priority           =       CRYPT_S390_COMPOSITE_PRIORITY,
 209         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
 210         .cra_blocksize          =       AES_BLOCK_SIZE,
 211         .cra_ctxsize            =       sizeof(struct s390_aes_ctx),
 212         .cra_type               =       &crypto_blkcipher_type,
 213         .cra_module             =       THIS_MODULE,
 214         .cra_list               =       LIST_HEAD_INIT(ecb_aes_alg.cra_list),
 215         .cra_u                  =       {
 216                 .blkcipher = {
 217                         .min_keysize            =       AES_MIN_KEY_SIZE,
 218                         .max_keysize            =       AES_MAX_KEY_SIZE,
 219                         .setkey                 =       ecb_aes_set_key,
 220                         .encrypt                =       ecb_aes_encrypt,
 221                         .decrypt                =       ecb_aes_decrypt,
 222                 }
 223         }
 224 };
 225
 226 static int cbc_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 227                            unsigned int key_len)
 228 {
 229         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 230
 231         switch (key_len) {
 232         case 16:
 233                 sctx->enc = KMC_AES_128_ENCRYPT;
 234                 sctx->dec = KMC_AES_128_DECRYPT;
 235                 break;
 236         case 24:
 237                 sctx->enc = KMC_AES_192_ENCRYPT;
 238                 sctx->dec = KMC_AES_192_DECRYPT;
 239                 break;
 240         case 32:
 241                 sctx->enc = KMC_AES_256_ENCRYPT;
 242                 sctx->dec = KMC_AES_256_DECRYPT;
 243                 break;
 244         }
 245
 246         return aes_set_key(tfm, in_key, key_len);
 247 }
 248
 249 static int cbc_aes_crypt(struct blkcipher_desc *desc, long func, void *param,
 250                          struct blkcipher_walk *walk)
 251 {
 252         int ret = blkcipher_walk_virt(desc, walk);
 253         unsigned int nbytes = walk->nbytes;
 254
 255         if (!nbytes)
 256                 goto out;
 257
 258         memcpy(param, walk->iv, AES_BLOCK_SIZE);
 259         do {
 260                 /* only use complete blocks */
 261                 unsigned int n = nbytes & ~(AES_BLOCK_SIZE - 1);
 262                 u8 *out = walk->dst.virt.addr;
 263                 u8 *in = walk->src.virt.addr;
 264
 265                 ret = crypt_s390_kmc(func, param, out, in, n);
 266                 BUG_ON((ret < 0) || (ret != n));
 267
 268                 nbytes &= AES_BLOCK_SIZE - 1;
 269                 ret = blkcipher_walk_done(desc, walk, nbytes);
 270         } while ((nbytes = walk->nbytes));
 271         memcpy(walk->iv, param, AES_BLOCK_SIZE);
 272
 273 out:
 274         return ret;
 275 }
 276
 277 static int cbc_aes_encrypt(struct blkcipher_desc *desc,
 278                            struct scatterlist *dst, struct scatterlist *src,
 279                            unsigned int nbytes)
 280 {
 281         struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
 282         struct blkcipher_walk walk;
 283
 284         blkcipher_walk_init(&walk, dst, src, nbytes);
 285         return cbc_aes_crypt(desc, sctx->enc, sctx->iv, &walk);
 286 }
 287
 288 static int cbc_aes_decrypt(struct blkcipher_desc *desc,
 289                            struct scatterlist *dst, struct scatterlist *src,
 290                            unsigned int nbytes)
 291 {
 292         struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
 293         struct blkcipher_walk walk;
 294
 295         blkcipher_walk_init(&walk, dst, src, nbytes);
 296         return cbc_aes_crypt(desc, sctx->dec, sctx->iv, &walk);
 297 }
 298
 299 static struct crypto_alg cbc_aes_alg = {
 300         .cra_name               =       "cbc(aes)",
 301         .cra_driver_name        =       "cbc-aes-s390",
 302         .cra_priority           =       CRYPT_S390_COMPOSITE_PRIORITY,
 303         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
 304         .cra_blocksize          =       AES_BLOCK_SIZE,
 305         .cra_ctxsize            =       sizeof(struct s390_aes_ctx),
 306         .cra_type               =       &crypto_blkcipher_type,
 307         .cra_module             =       THIS_MODULE,
 308         .cra_list               =       LIST_HEAD_INIT(cbc_aes_alg.cra_list),
 309         .cra_u                  =       {
 310                 .blkcipher = {
 311                         .min_keysize            =       AES_MIN_KEY_SIZE,
 312                         .max_keysize            =       AES_MAX_KEY_SIZE,
 313                         .ivsize                 =       AES_BLOCK_SIZE,
 314                         .setkey                 =       cbc_aes_set_key,
 315                         .encrypt                =       cbc_aes_encrypt,
 316                         .decrypt                =       cbc_aes_decrypt,
 317                 }
 318         }
 319 };
 320
 321 static int __init aes_init(void)
 322 {
 323         int ret;
 324
 325         if (crypt_s390_func_available(KM_AES_128_ENCRYPT))
 326                 keylen_flag |= AES_KEYLEN_128;
 327         if (crypt_s390_func_available(KM_AES_192_ENCRYPT))
 328                 keylen_flag |= AES_KEYLEN_192;
 329         if (crypt_s390_func_available(KM_AES_256_ENCRYPT))
 330                 keylen_flag |= AES_KEYLEN_256;
 331
 332         if (!keylen_flag)
 333                 return -EOPNOTSUPP;
 334
 335         /* z9 109 and z9 BC/EC only support 128 bit key length */
 336         if (keylen_flag == AES_KEYLEN_128)
 337                 printk(KERN_INFO
 338                        "aes_s390: hardware acceleration only available for"
 339                        "128 bit keys\n");
 340
 341         ret = crypto_register_alg(&aes_alg);
 342         if (ret)
 343                 goto aes_err;
 344
 345         ret = crypto_register_alg(&ecb_aes_alg);
 346         if (ret)
 347                 goto ecb_aes_err;
 348
 349         ret = crypto_register_alg(&cbc_aes_alg);
 350         if (ret)
 351                 goto cbc_aes_err;
 352
 353 out:
 354         return ret;
 355
 356 cbc_aes_err:
 357         crypto_unregister_alg(&ecb_aes_alg);
 358 ecb_aes_err:
 359         crypto_unregister_alg(&aes_alg);
 360 aes_err:
 361         goto out;
 362 }
 363
 364 static void __exit aes_fini(void)
 365 {
 366         crypto_unregister_alg(&cbc_aes_alg);
 367         crypto_unregister_alg(&ecb_aes_alg);
 368         crypto_unregister_alg(&aes_alg);
 369 }
 370
 371 module_init(aes_init);
 372 module_exit(aes_fini);
 373
 374 MODULE_ALIAS("aes");
 375
 376 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
 377 MODULE_LICENSE("GPL");
 378