arch/x86/crypto/blowfish_glue.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Glue Code for assembler optimized version of Blowfish
   4  *
   5  * Copyright (c) 2011 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
   6  *
   7  * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
   8  *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
   9  */
  10
  11 #include <crypto/algapi.h>
  12 #include <crypto/blowfish.h>
  13 #include <crypto/internal/skcipher.h>
  14 #include <linux/crypto.h>
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18
  19 /* regular block cipher functions */
  20 asmlinkage void __blowfish_enc_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src,
  21                                    bool xor);
  22 asmlinkage void blowfish_dec_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src);
  23
  24 /* 4-way parallel cipher functions */
  25 asmlinkage void __blowfish_enc_blk_4way(struct bf_ctx *ctx, u8 *dst,
  26                                         const u8 *src, bool xor);
  27 asmlinkage void blowfish_dec_blk_4way(struct bf_ctx *ctx, u8 *dst,
  28                                       const u8 *src);
  29
  30 static inline void blowfish_enc_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src)
  31 {
  32         __blowfish_enc_blk(ctx, dst, src, false);
  33 }
  34
  35 static inline void blowfish_enc_blk_4way(struct bf_ctx *ctx, u8 *dst,
  36                                          const u8 *src)
  37 {
  38         __blowfish_enc_blk_4way(ctx, dst, src, false);
  39 }
  40
  41 static void blowfish_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
  42 {
  43         blowfish_enc_blk(crypto_tfm_ctx(tfm), dst, src);
  44 }
  45
  46 static void blowfish_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
  47 {
  48         blowfish_dec_blk(crypto_tfm_ctx(tfm), dst, src);
  49 }
  50
  51 static int blowfish_setkey_skcipher(struct crypto_skcipher *tfm,
  52                                     const u8 *key, unsigned int keylen)
  53 {
  54         return blowfish_setkey(&tfm->base, key, keylen);
  55 }
  56
  57 static int ecb_crypt(struct skcipher_request *req,
  58                      void (*fn)(struct bf_ctx *, u8 *, const u8 *),
  59                      void (*fn_4way)(struct bf_ctx *, u8 *, const u8 *))
  60 {
  61         unsigned int bsize = BF_BLOCK_SIZE;
  62         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  63         struct bf_ctx *ctx = crypto_skcipher_ctx(tfm);
  64         struct skcipher_walk walk;
  65         unsigned int nbytes;
  66         int err;
  67
  68         err = skcipher_walk_virt(&walk, req, false);
  69
  70         while ((nbytes = walk.nbytes)) {
  71                 u8 *wsrc = walk.src.virt.addr;
  72                 u8 *wdst = walk.dst.virt.addr;
  73
  74                 /* Process four block batch */
  75                 if (nbytes >= bsize * 4) {
  76                         do {
  77                                 fn_4way(ctx, wdst, wsrc);
  78
  79                                 wsrc += bsize * 4;
  80                                 wdst += bsize * 4;
  81                                 nbytes -= bsize * 4;
  82                         } while (nbytes >= bsize * 4);
  83
  84                         if (nbytes < bsize)
  85                                 goto done;
  86                 }
  87
  88                 /* Handle leftovers */
  89                 do {
  90                         fn(ctx, wdst, wsrc);
  91
  92                         wsrc += bsize;
  93                         wdst += bsize;
  94                         nbytes -= bsize;
  95                 } while (nbytes >= bsize);
  96
  97 done:
  98                 err = skcipher_walk_done(&walk, nbytes);
  99         }
 100
 101         return err;
 102 }
 103
 104 static int ecb_encrypt(struct skcipher_request *req)
 105 {
 106         return ecb_crypt(req, blowfish_enc_blk, blowfish_enc_blk_4way);
 107 }
 108
 109 static int ecb_decrypt(struct skcipher_request *req)
 110 {
 111         return ecb_crypt(req, blowfish_dec_blk, blowfish_dec_blk_4way);
 112 }
 113
 114 static unsigned int __cbc_encrypt(struct bf_ctx *ctx,
 115                                   struct skcipher_walk *walk)
 116 {
 117         unsigned int bsize = BF_BLOCK_SIZE;
 118         unsigned int nbytes = walk->nbytes;
 119         u64 *src = (u64 *)walk->src.virt.addr;
 120         u64 *dst = (u64 *)walk->dst.virt.addr;
 121         u64 *iv = (u64 *)walk->iv;
 122
 123         do {
 124                 *dst = *src ^ *iv;
 125                 blowfish_enc_blk(ctx, (u8 *)dst, (u8 *)dst);
 126                 iv = dst;
 127
 128                 src += 1;
 129                 dst += 1;
 130                 nbytes -= bsize;
 131         } while (nbytes >= bsize);
 132
 133         *(u64 *)walk->iv = *iv;
 134         return nbytes;
 135 }
 136
 137 static int cbc_encrypt(struct skcipher_request *req)
 138 {
 139         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 140         struct bf_ctx *ctx = crypto_skcipher_ctx(tfm);
 141         struct skcipher_walk walk;
 142         unsigned int nbytes;
 143         int err;
 144
 145         err = skcipher_walk_virt(&walk, req, false);
 146
 147         while ((nbytes = walk.nbytes)) {
 148                 nbytes = __cbc_encrypt(ctx, &walk);
 149                 err = skcipher_walk_done(&walk, nbytes);
 150         }
 151
 152         return err;
 153 }
 154
 155 static unsigned int __cbc_decrypt(struct bf_ctx *ctx,
 156                                   struct skcipher_walk *walk)
 157 {
 158         unsigned int bsize = BF_BLOCK_SIZE;
 159         unsigned int nbytes = walk->nbytes;
 160         u64 *src = (u64 *)walk->src.virt.addr;
 161         u64 *dst = (u64 *)walk->dst.virt.addr;
 162         u64 ivs[4 - 1];
 163         u64 last_iv;
 164
 165         /* Start of the last block. */
 166         src += nbytes / bsize - 1;
 167         dst += nbytes / bsize - 1;
 168
 169         last_iv = *src;
 170
 171         /* Process four block batch */
 172         if (nbytes >= bsize * 4) {
 173                 do {
 174                         nbytes -= bsize * 4 - bsize;
 175                         src -= 4 - 1;
 176                         dst -= 4 - 1;
 177
 178                         ivs[0] = src[0];
 179                         ivs[1] = src[1];
 180                         ivs[2] = src[2];
 181
 182                         blowfish_dec_blk_4way(ctx, (u8 *)dst, (u8 *)src);
 183
 184                         dst[1] ^= ivs[0];
 185                         dst[2] ^= ivs[1];
 186                         dst[3] ^= ivs[2];
 187
 188                         nbytes -= bsize;
 189                         if (nbytes < bsize)
 190                                 goto done;
 191
 192                         *dst ^= *(src - 1);
 193                         src -= 1;
 194                         dst -= 1;
 195                 } while (nbytes >= bsize * 4);
 196         }
 197
 198         /* Handle leftovers */
 199         for (;;) {
 200                 blowfish_dec_blk(ctx, (u8 *)dst, (u8 *)src);
 201
 202                 nbytes -= bsize;
 203                 if (nbytes < bsize)
 204                         break;
 205
 206                 *dst ^= *(src - 1);
 207                 src -= 1;
 208                 dst -= 1;
 209         }
 210
 211 done:
 212         *dst ^= *(u64 *)walk->iv;
 213         *(u64 *)walk->iv = last_iv;
 214
 215         return nbytes;
 216 }
 217
 218 static int cbc_decrypt(struct skcipher_request *req)
 219 {
 220         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 221         struct bf_ctx *ctx = crypto_skcipher_ctx(tfm);
 222         struct skcipher_walk walk;
 223         unsigned int nbytes;
 224         int err;
 225
 226         err = skcipher_walk_virt(&walk, req, false);
 227
 228         while ((nbytes = walk.nbytes)) {
 229                 nbytes = __cbc_decrypt(ctx, &walk);
 230                 err = skcipher_walk_done(&walk, nbytes);
 231         }
 232
 233         return err;
 234 }
 235
 236 static struct crypto_alg bf_cipher_alg = {
 237         .cra_name               = "blowfish",
 238         .cra_driver_name        = "blowfish-asm",
 239         .cra_priority           = 200,
 240         .cra_flags              = CRYPTO_ALG_TYPE_CIPHER,
 241         .cra_blocksize          = BF_BLOCK_SIZE,
 242         .cra_ctxsize            = sizeof(struct bf_ctx),
 243         .cra_alignmask          = 0,
 244         .cra_module             = THIS_MODULE,
 245         .cra_u = {
 246                 .cipher = {
 247                         .cia_min_keysize        = BF_MIN_KEY_SIZE,
 248                         .cia_max_keysize        = BF_MAX_KEY_SIZE,
 249                         .cia_setkey             = blowfish_setkey,
 250                         .cia_encrypt            = blowfish_encrypt,
 251                         .cia_decrypt            = blowfish_decrypt,
 252                 }
 253         }
 254 };
 255
 256 static struct skcipher_alg bf_skcipher_algs[] = {
 257         {
 258                 .base.cra_name          = "ecb(blowfish)",
 259                 .base.cra_driver_name   = "ecb-blowfish-asm",
 260                 .base.cra_priority      = 300,
 261                 .base.cra_blocksize     = BF_BLOCK_SIZE,
 262                 .base.cra_ctxsize       = sizeof(struct bf_ctx),
 263                 .base.cra_module        = THIS_MODULE,
 264                 .min_keysize            = BF_MIN_KEY_SIZE,
 265                 .max_keysize            = BF_MAX_KEY_SIZE,
 266                 .setkey                 = blowfish_setkey_skcipher,
 267                 .encrypt                = ecb_encrypt,
 268                 .decrypt                = ecb_decrypt,
 269         }, {
 270                 .base.cra_name          = "cbc(blowfish)",
 271                 .base.cra_driver_name   = "cbc-blowfish-asm",
 272                 .base.cra_priority      = 300,
 273                 .base.cra_blocksize     = BF_BLOCK_SIZE,
 274                 .base.cra_ctxsize       = sizeof(struct bf_ctx),
 275                 .base.cra_module        = THIS_MODULE,
 276                 .min_keysize            = BF_MIN_KEY_SIZE,
 277                 .max_keysize            = BF_MAX_KEY_SIZE,
 278                 .ivsize                 = BF_BLOCK_SIZE,
 279                 .setkey                 = blowfish_setkey_skcipher,
 280                 .encrypt                = cbc_encrypt,
 281                 .decrypt                = cbc_decrypt,
 282         },
 283 };
 284
 285 static bool is_blacklisted_cpu(void)
 286 {
 287         if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
 288                 return false;
 289
 290         if (boot_cpu_data.x86 == 0x0f) {
 291                 /*
 292                  * On Pentium 4, blowfish-x86_64 is slower than generic C
 293                  * implementation because use of 64bit rotates (which are really
 294                  * slow on P4). Therefore blacklist P4s.
 295                  */
 296                 return true;
 297         }
 298
 299         return false;
 300 }
 301
 302 static int force;
 303 module_param(force, int, 0);
 304 MODULE_PARM_DESC(force, "Force module load, ignore CPU blacklist");
 305
 306 static int __init blowfish_init(void)
 307 {
 308         int err;
 309
 310         if (!force && is_blacklisted_cpu()) {
 311                 printk(KERN_INFO
 312                         "blowfish-x86_64: performance on this CPU "
 313                         "would be suboptimal: disabling "
 314                         "blowfish-x86_64.\n");
 315                 return -ENODEV;
 316         }
 317
 318         err = crypto_register_alg(&bf_cipher_alg);
 319         if (err)
 320                 return err;
 321
 322         err = crypto_register_skciphers(bf_skcipher_algs,
 323                                         ARRAY_SIZE(bf_skcipher_algs));
 324         if (err)
 325                 crypto_unregister_alg(&bf_cipher_alg);
 326
 327         return err;
 328 }
 329
 330 static void __exit blowfish_fini(void)
 331 {
 332         crypto_unregister_alg(&bf_cipher_alg);
 333         crypto_unregister_skciphers(bf_skcipher_algs,
 334                                     ARRAY_SIZE(bf_skcipher_algs));
 335 }
 336
 337 module_init(blowfish_init);
 338 module_exit(blowfish_fini);
 339
 340 MODULE_LICENSE("GPL");
 341 MODULE_DESCRIPTION("Blowfish Cipher Algorithm, asm optimized");
 342 MODULE_ALIAS_CRYPTO("blowfish");
 343 MODULE_ALIAS_CRYPTO("blowfish-asm");