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_generic.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                                         CRYPTO_ALG_NEED_FALLBACK,
 124         .cra_blocksize          =       AES_BLOCK_SIZE,
 125         .cra_ctxsize            =       sizeof(struct s390_aes_ctx),
 126         .cra_module             =       THIS_MODULE,
 127         .cra_list               =       LIST_HEAD_INIT(aes_alg.cra_list),
 128         .cra_u                  =       {
 129                 .cipher = {
 130                         .cia_min_keysize        =       AES_MIN_KEY_SIZE,
 131                         .cia_max_keysize        =       AES_MAX_KEY_SIZE,
 132                         .cia_setkey             =       aes_set_key,
 133                         .cia_encrypt            =       aes_encrypt,
 134                         .cia_decrypt            =       aes_decrypt,
 135                 }
 136         }
 137 };
 138
 139 static int ecb_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 140                            unsigned int key_len)
 141 {
 142         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 143
 144         switch (key_len) {
 145         case 16:
 146                 sctx->enc = KM_AES_128_ENCRYPT;
 147                 sctx->dec = KM_AES_128_DECRYPT;
 148                 break;
 149         case 24:
 150                 sctx->enc = KM_AES_192_ENCRYPT;
 151                 sctx->dec = KM_AES_192_DECRYPT;
 152                 break;
 153         case 32:
 154                 sctx->enc = KM_AES_256_ENCRYPT;
 155                 sctx->dec = KM_AES_256_DECRYPT;
 156                 break;
 157         }
 158
 159         return aes_set_key(tfm, in_key, key_len);
 160 }
 161
 162 static int ecb_aes_crypt(struct blkcipher_desc *desc, long func, void *param,
 163                          struct blkcipher_walk *walk)
 164 {
 165         int ret = blkcipher_walk_virt(desc, walk);
 166         unsigned int nbytes;
 167
 168         while ((nbytes = walk->nbytes)) {
 169                 /* only use complete blocks */
 170                 unsigned int n = nbytes & ~(AES_BLOCK_SIZE - 1);
 171                 u8 *out = walk->dst.virt.addr;
 172                 u8 *in = walk->src.virt.addr;
 173
 174                 ret = crypt_s390_km(func, param, out, in, n);
 175                 BUG_ON((ret < 0) || (ret != n));
 176
 177                 nbytes &= AES_BLOCK_SIZE - 1;
 178                 ret = blkcipher_walk_done(desc, walk, nbytes);
 179         }
 180
 181         return ret;
 182 }
 183
 184 static int ecb_aes_encrypt(struct blkcipher_desc *desc,
 185                            struct scatterlist *dst, struct scatterlist *src,
 186                            unsigned int nbytes)
 187 {
 188         struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
 189         struct blkcipher_walk walk;
 190
 191         blkcipher_walk_init(&walk, dst, src, nbytes);
 192         return ecb_aes_crypt(desc, sctx->enc, sctx->key, &walk);
 193 }
 194
 195 static int ecb_aes_decrypt(struct blkcipher_desc *desc,
 196                            struct scatterlist *dst, struct scatterlist *src,
 197                            unsigned int nbytes)
 198 {
 199         struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
 200         struct blkcipher_walk walk;
 201
 202         blkcipher_walk_init(&walk, dst, src, nbytes);
 203         return ecb_aes_crypt(desc, sctx->dec, sctx->key, &walk);
 204 }
 205
 206 static struct crypto_alg ecb_aes_alg = {
 207         .cra_name               =       "ecb(aes)",
 208         .cra_driver_name        =       "ecb-aes-s390",
 209         .cra_priority           =       CRYPT_S390_COMPOSITE_PRIORITY,
 210         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER |
 211                                         CRYPTO_ALG_NEED_FALLBACK,
 212         .cra_blocksize          =       AES_BLOCK_SIZE,
 213         .cra_ctxsize            =       sizeof(struct s390_aes_ctx),
 214         .cra_type               =       &crypto_blkcipher_type,
 215         .cra_module             =       THIS_MODULE,
 216         .cra_list               =       LIST_HEAD_INIT(ecb_aes_alg.cra_list),
 217         .cra_u                  =       {
 218                 .blkcipher = {
 219                         .min_keysize            =       AES_MIN_KEY_SIZE,
 220                         .max_keysize            =       AES_MAX_KEY_SIZE,
 221                         .setkey                 =       ecb_aes_set_key,
 222                         .encrypt                =       ecb_aes_encrypt,
 223                         .decrypt                =       ecb_aes_decrypt,
 224                 }
 225         }
 226 };
 227
 228 static int cbc_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 229                            unsigned int key_len)
 230 {
 231         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 232
 233         switch (key_len) {
 234         case 16:
 235                 sctx->enc = KMC_AES_128_ENCRYPT;
 236                 sctx->dec = KMC_AES_128_DECRYPT;
 237                 break;
 238         case 24:
 239                 sctx->enc = KMC_AES_192_ENCRYPT;
 240                 sctx->dec = KMC_AES_192_DECRYPT;
 241                 break;
 242         case 32:
 243                 sctx->enc = KMC_AES_256_ENCRYPT;
 244                 sctx->dec = KMC_AES_256_DECRYPT;
 245                 break;
 246         }
 247
 248         return aes_set_key(tfm, in_key, key_len);
 249 }
 250
 251 static int cbc_aes_crypt(struct blkcipher_desc *desc, long func, void *param,
 252                          struct blkcipher_walk *walk)
 253 {
 254         int ret = blkcipher_walk_virt(desc, walk);
 255         unsigned int nbytes = walk->nbytes;
 256
 257         if (!nbytes)
 258                 goto out;
 259
 260         memcpy(param, walk->iv, AES_BLOCK_SIZE);
 261         do {
 262                 /* only use complete blocks */
 263                 unsigned int n = nbytes & ~(AES_BLOCK_SIZE - 1);
 264                 u8 *out = walk->dst.virt.addr;
 265                 u8 *in = walk->src.virt.addr;
 266
 267                 ret = crypt_s390_kmc(func, param, out, in, n);
 268                 BUG_ON((ret < 0) || (ret != n));
 269
 270                 nbytes &= AES_BLOCK_SIZE - 1;
 271                 ret = blkcipher_walk_done(desc, walk, nbytes);
 272         } while ((nbytes = walk->nbytes));
 273         memcpy(walk->iv, param, AES_BLOCK_SIZE);
 274
 275 out:
 276         return ret;
 277 }
 278
 279 static int cbc_aes_encrypt(struct blkcipher_desc *desc,
 280                            struct scatterlist *dst, struct scatterlist *src,
 281                            unsigned int nbytes)
 282 {
 283         struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
 284         struct blkcipher_walk walk;
 285
 286         blkcipher_walk_init(&walk, dst, src, nbytes);
 287         return cbc_aes_crypt(desc, sctx->enc, sctx->iv, &walk);
 288 }
 289
 290 static int cbc_aes_decrypt(struct blkcipher_desc *desc,
 291                            struct scatterlist *dst, struct scatterlist *src,
 292                            unsigned int nbytes)
 293 {
 294         struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
 295         struct blkcipher_walk walk;
 296
 297         blkcipher_walk_init(&walk, dst, src, nbytes);
 298         return cbc_aes_crypt(desc, sctx->dec, sctx->iv, &walk);
 299 }
 300
 301 static struct crypto_alg cbc_aes_alg = {
 302         .cra_name               =       "cbc(aes)",
 303         .cra_driver_name        =       "cbc-aes-s390",
 304         .cra_priority           =       CRYPT_S390_COMPOSITE_PRIORITY,
 305         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER |
 306                                         CRYPTO_ALG_NEED_FALLBACK,
 307         .cra_blocksize          =       AES_BLOCK_SIZE,
 308         .cra_ctxsize            =       sizeof(struct s390_aes_ctx),
 309         .cra_type               =       &crypto_blkcipher_type,
 310         .cra_module             =       THIS_MODULE,
 311         .cra_list               =       LIST_HEAD_INIT(cbc_aes_alg.cra_list),
 312         .cra_u                  =       {
 313                 .blkcipher = {
 314                         .min_keysize            =       AES_MIN_KEY_SIZE,
 315                         .max_keysize            =       AES_MAX_KEY_SIZE,
 316                         .ivsize                 =       AES_BLOCK_SIZE,
 317                         .setkey                 =       cbc_aes_set_key,
 318                         .encrypt                =       cbc_aes_encrypt,
 319                         .decrypt                =       cbc_aes_decrypt,
 320                 }
 321         }
 322 };
 323
 324 static int __init aes_init(void)
 325 {
 326         int ret;
 327
 328         if (crypt_s390_func_available(KM_AES_128_ENCRYPT))
 329                 keylen_flag |= AES_KEYLEN_128;
 330         if (crypt_s390_func_available(KM_AES_192_ENCRYPT))
 331                 keylen_flag |= AES_KEYLEN_192;
 332         if (crypt_s390_func_available(KM_AES_256_ENCRYPT))
 333                 keylen_flag |= AES_KEYLEN_256;
 334
 335         if (!keylen_flag)
 336                 return -EOPNOTSUPP;
 337
 338         /* z9 109 and z9 BC/EC only support 128 bit key length */
 339         if (keylen_flag == AES_KEYLEN_128) {
 340                 aes_alg.cra_u.cipher.cia_max_keysize = AES_MIN_KEY_SIZE;
 341                 ecb_aes_alg.cra_u.blkcipher.max_keysize = AES_MIN_KEY_SIZE;
 342                 cbc_aes_alg.cra_u.blkcipher.max_keysize = AES_MIN_KEY_SIZE;
 343                 printk(KERN_INFO
 344                        "aes_s390: hardware acceleration only available for"
 345                        "128 bit keys\n");
 346         }
 347
 348         ret = crypto_register_alg(&aes_alg);
 349         if (ret)
 350                 goto aes_err;
 351
 352         ret = crypto_register_alg(&ecb_aes_alg);
 353         if (ret)
 354                 goto ecb_aes_err;
 355
 356         ret = crypto_register_alg(&cbc_aes_alg);
 357         if (ret)
 358                 goto cbc_aes_err;
 359
 360 out:
 361         return ret;
 362
 363 cbc_aes_err:
 364         crypto_unregister_alg(&ecb_aes_alg);
 365 ecb_aes_err:
 366         crypto_unregister_alg(&aes_alg);
 367 aes_err:
 368         goto out;
 369 }
 370
 371 static void __exit aes_fini(void)
 372 {
 373         crypto_unregister_alg(&cbc_aes_alg);
 374         crypto_unregister_alg(&ecb_aes_alg);
 375         crypto_unregister_alg(&aes_alg);
 376 }
 377
 378 module_init(aes_init);
 379 module_exit(aes_fini);
 380
 381 MODULE_ALIAS("aes");
 382
 383 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
 384 MODULE_LICENSE("GPL");
 385