arch/x86/crypto/sha1_ssse3_glue.c

   1 /*
   2  * Cryptographic API.
   3  *
   4  * Glue code for the SHA1 Secure Hash Algorithm assembler implementation using
   5  * Supplemental SSE3 instructions.
   6  *
   7  * This file is based on sha1_generic.c
   8  *
   9  * Copyright (c) Alan Smithee.
  10  * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
  11  * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
  12  * Copyright (c) Mathias Krause <minipli@googlemail.com>
  13  *
  14  * This program is free software; you can redistribute it and/or modify it
  15  * under the terms of the GNU General Public License as published by the Free
  16  * Software Foundation; either version 2 of the License, or (at your option)
  17  * any later version.
  18  *
  19  */
  20
  21 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  22
  23 #include <crypto/internal/hash.h>
  24 #include <linux/init.h>
  25 #include <linux/module.h>
  26 #include <linux/mm.h>
  27 #include <linux/cryptohash.h>
  28 #include <linux/types.h>
  29 #include <crypto/sha.h>
  30 #include <asm/byteorder.h>
  31 #include <asm/i387.h>
  32 #include <asm/xcr.h>
  33 #include <asm/xsave.h>
  34
  35
  36 asmlinkage void sha1_transform_ssse3(u32 *digest, const char *data,
  37                                      unsigned int rounds);
  38 #ifdef SHA1_ENABLE_AVX_SUPPORT
  39 asmlinkage void sha1_transform_avx(u32 *digest, const char *data,
  40                                    unsigned int rounds);
  41 #endif
  42
  43 static asmlinkage void (*sha1_transform_asm)(u32 *, const char *, unsigned int);
  44
  45
  46 static int sha1_ssse3_init(struct shash_desc *desc)
  47 {
  48         struct sha1_state *sctx = shash_desc_ctx(desc);
  49
  50         *sctx = (struct sha1_state){
  51                 .state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
  52         };
  53
  54         return 0;
  55 }
  56
  57 static int __sha1_ssse3_update(struct shash_desc *desc, const u8 *data,
  58                                unsigned int len, unsigned int partial)
  59 {
  60         struct sha1_state *sctx = shash_desc_ctx(desc);
  61         unsigned int done = 0;
  62
  63         sctx->count += len;
  64
  65         if (partial) {
  66                 done = SHA1_BLOCK_SIZE - partial;
  67                 memcpy(sctx->buffer + partial, data, done);
  68                 sha1_transform_asm(sctx->state, sctx->buffer, 1);
  69         }
  70
  71         if (len - done >= SHA1_BLOCK_SIZE) {
  72                 const unsigned int rounds = (len - done) / SHA1_BLOCK_SIZE;
  73
  74                 sha1_transform_asm(sctx->state, data + done, rounds);
  75                 done += rounds * SHA1_BLOCK_SIZE;
  76         }
  77
  78         memcpy(sctx->buffer, data + done, len - done);
  79
  80         return 0;
  81 }
  82
  83 static int sha1_ssse3_update(struct shash_desc *desc, const u8 *data,
  84                              unsigned int len)
  85 {
  86         struct sha1_state *sctx = shash_desc_ctx(desc);
  87         unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
  88         int res;
  89
  90         /* Handle the fast case right here */
  91         if (partial + len < SHA1_BLOCK_SIZE) {
  92                 sctx->count += len;
  93                 memcpy(sctx->buffer + partial, data, len);
  94
  95                 return 0;
  96         }
  97
  98         if (!irq_fpu_usable()) {
  99                 res = crypto_sha1_update(desc, data, len);
 100         } else {
 101                 kernel_fpu_begin();
 102                 res = __sha1_ssse3_update(desc, data, len, partial);
 103                 kernel_fpu_end();
 104         }
 105
 106         return res;
 107 }
 108
 109
 110 /* Add padding and return the message digest. */
 111 static int sha1_ssse3_final(struct shash_desc *desc, u8 *out)
 112 {
 113         struct sha1_state *sctx = shash_desc_ctx(desc);
 114         unsigned int i, index, padlen;
 115         __be32 *dst = (__be32 *)out;
 116         __be64 bits;
 117         static const u8 padding[SHA1_BLOCK_SIZE] = { 0x80, };
 118
 119         bits = cpu_to_be64(sctx->count << 3);
 120
 121         /* Pad out to 56 mod 64 and append length */
 122         index = sctx->count % SHA1_BLOCK_SIZE;
 123         padlen = (index < 56) ? (56 - index) : ((SHA1_BLOCK_SIZE+56) - index);
 124         if (!irq_fpu_usable()) {
 125                 crypto_sha1_update(desc, padding, padlen);
 126                 crypto_sha1_update(desc, (const u8 *)&bits, sizeof(bits));
 127         } else {
 128                 kernel_fpu_begin();
 129                 /* We need to fill a whole block for __sha1_ssse3_update() */
 130                 if (padlen <= 56) {
 131                         sctx->count += padlen;
 132                         memcpy(sctx->buffer + index, padding, padlen);
 133                 } else {
 134                         __sha1_ssse3_update(desc, padding, padlen, index);
 135                 }
 136                 __sha1_ssse3_update(desc, (const u8 *)&bits, sizeof(bits), 56);
 137                 kernel_fpu_end();
 138         }
 139
 140         /* Store state in digest */
 141         for (i = 0; i < 5; i++)
 142                 dst[i] = cpu_to_be32(sctx->state[i]);
 143
 144         /* Wipe context */
 145         memset(sctx, 0, sizeof(*sctx));
 146
 147         return 0;
 148 }
 149
 150 static int sha1_ssse3_export(struct shash_desc *desc, void *out)
 151 {
 152         struct sha1_state *sctx = shash_desc_ctx(desc);
 153
 154         memcpy(out, sctx, sizeof(*sctx));
 155
 156         return 0;
 157 }
 158
 159 static int sha1_ssse3_import(struct shash_desc *desc, const void *in)
 160 {
 161         struct sha1_state *sctx = shash_desc_ctx(desc);
 162
 163         memcpy(sctx, in, sizeof(*sctx));
 164
 165         return 0;
 166 }
 167
 168 static struct shash_alg alg = {
 169         .digestsize     =       SHA1_DIGEST_SIZE,
 170         .init           =       sha1_ssse3_init,
 171         .update         =       sha1_ssse3_update,
 172         .final          =       sha1_ssse3_final,
 173         .export         =       sha1_ssse3_export,
 174         .import         =       sha1_ssse3_import,
 175         .descsize       =       sizeof(struct sha1_state),
 176         .statesize      =       sizeof(struct sha1_state),
 177         .base           =       {
 178                 .cra_name       =       "sha1",
 179                 .cra_driver_name=       "sha1-ssse3",
 180                 .cra_priority   =       150,
 181                 .cra_flags      =       CRYPTO_ALG_TYPE_SHASH,
 182                 .cra_blocksize  =       SHA1_BLOCK_SIZE,
 183                 .cra_module     =       THIS_MODULE,
 184         }
 185 };
 186
 187 #ifdef SHA1_ENABLE_AVX_SUPPORT
 188 static bool __init avx_usable(void)
 189 {
 190         u64 xcr0;
 191
 192         if (!cpu_has_avx || !cpu_has_osxsave)
 193                 return false;
 194
 195         xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
 196         if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
 197                 pr_info("AVX detected but unusable.\n");
 198
 199                 return false;
 200         }
 201
 202         return true;
 203 }
 204 #endif
 205
 206 static int __init sha1_ssse3_mod_init(void)
 207 {
 208         /* test for SSSE3 first */
 209         if (cpu_has_ssse3)
 210                 sha1_transform_asm = sha1_transform_ssse3;
 211
 212 #ifdef SHA1_ENABLE_AVX_SUPPORT
 213         /* allow AVX to override SSSE3, it's a little faster */
 214         if (avx_usable())
 215                 sha1_transform_asm = sha1_transform_avx;
 216 #endif
 217
 218         if (sha1_transform_asm) {
 219                 pr_info("Using %s optimized SHA-1 implementation\n",
 220                         sha1_transform_asm == sha1_transform_ssse3 ? "SSSE3"
 221                                                                    : "AVX");
 222                 return crypto_register_shash(&alg);
 223         }
 224         pr_info("Neither AVX nor SSSE3 is available/usable.\n");
 225
 226         return -ENODEV;
 227 }
 228
 229 static void __exit sha1_ssse3_mod_fini(void)
 230 {
 231         crypto_unregister_shash(&alg);
 232 }
 233
 234 module_init(sha1_ssse3_mod_init);
 235 module_exit(sha1_ssse3_mod_fini);
 236
 237 MODULE_LICENSE("GPL");
 238 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm, Supplemental SSE3 accelerated");
 239
 240 MODULE_ALIAS("sha1");