arch/arm/crypto/sha1-ce-glue.c

   1 /*
   2  * sha1-ce-glue.c - SHA-1 secure hash using ARMv8 Crypto Extensions
   3  *
   4  * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <crypto/internal/hash.h>
  12 #include <crypto/sha.h>
  13 #include <linux/crypto.h>
  14 #include <linux/module.h>
  15
  16 #include <asm/crypto/sha1.h>
  17 #include <asm/hwcap.h>
  18 #include <asm/neon.h>
  19 #include <asm/simd.h>
  20 #include <asm/unaligned.h>
  21
  22 MODULE_DESCRIPTION("SHA1 secure hash using ARMv8 Crypto Extensions");
  23 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  24 MODULE_LICENSE("GPL v2");
  25
  26 asmlinkage void sha1_ce_transform(int blocks, u8 const *src, u32 *state,
  27                                   u8 *head);
  28
  29 static int sha1_init(struct shash_desc *desc)
  30 {
  31         struct sha1_state *sctx = shash_desc_ctx(desc);
  32
  33         *sctx = (struct sha1_state){
  34                 .state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
  35         };
  36         return 0;
  37 }
  38
  39 static int sha1_update(struct shash_desc *desc, const u8 *data,
  40                        unsigned int len)
  41 {
  42         struct sha1_state *sctx = shash_desc_ctx(desc);
  43         unsigned int partial;
  44
  45         if (!may_use_simd())
  46                 return sha1_update_arm(desc, data, len);
  47
  48         partial = sctx->count % SHA1_BLOCK_SIZE;
  49         sctx->count += len;
  50
  51         if ((partial + len) >= SHA1_BLOCK_SIZE) {
  52                 int blocks;
  53
  54                 if (partial) {
  55                         int p = SHA1_BLOCK_SIZE - partial;
  56
  57                         memcpy(sctx->buffer + partial, data, p);
  58                         data += p;
  59                         len -= p;
  60                 }
  61
  62                 blocks = len / SHA1_BLOCK_SIZE;
  63                 len %= SHA1_BLOCK_SIZE;
  64
  65                 kernel_neon_begin();
  66                 sha1_ce_transform(blocks, data, sctx->state,
  67                                   partial ? sctx->buffer : NULL);
  68                 kernel_neon_end();
  69
  70                 data += blocks * SHA1_BLOCK_SIZE;
  71                 partial = 0;
  72         }
  73         if (len)
  74                 memcpy(sctx->buffer + partial, data, len);
  75         return 0;
  76 }
  77
  78 static int sha1_final(struct shash_desc *desc, u8 *out)
  79 {
  80         static const u8 padding[SHA1_BLOCK_SIZE] = { 0x80, };
  81
  82         struct sha1_state *sctx = shash_desc_ctx(desc);
  83         __be64 bits = cpu_to_be64(sctx->count << 3);
  84         __be32 *dst = (__be32 *)out;
  85         int i;
  86
  87         u32 padlen = SHA1_BLOCK_SIZE
  88                      - ((sctx->count + sizeof(bits)) % SHA1_BLOCK_SIZE);
  89
  90         sha1_update(desc, padding, padlen);
  91         sha1_update(desc, (const u8 *)&bits, sizeof(bits));
  92
  93         for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++)
  94                 put_unaligned_be32(sctx->state[i], dst++);
  95
  96         *sctx = (struct sha1_state){};
  97         return 0;
  98 }
  99
 100 static int sha1_export(struct shash_desc *desc, void *out)
 101 {
 102         struct sha1_state *sctx = shash_desc_ctx(desc);
 103         struct sha1_state *dst = out;
 104
 105         *dst = *sctx;
 106         return 0;
 107 }
 108
 109 static int sha1_import(struct shash_desc *desc, const void *in)
 110 {
 111         struct sha1_state *sctx = shash_desc_ctx(desc);
 112         struct sha1_state const *src = in;
 113
 114         *sctx = *src;
 115         return 0;
 116 }
 117
 118 static struct shash_alg alg = {
 119         .init                   = sha1_init,
 120         .update                 = sha1_update,
 121         .final                  = sha1_final,
 122         .export                 = sha1_export,
 123         .import                 = sha1_import,
 124         .descsize               = sizeof(struct sha1_state),
 125         .digestsize             = SHA1_DIGEST_SIZE,
 126         .statesize              = sizeof(struct sha1_state),
 127         .base                   = {
 128                 .cra_name               = "sha1",
 129                 .cra_driver_name        = "sha1-ce",
 130                 .cra_priority           = 200,
 131                 .cra_flags              = CRYPTO_ALG_TYPE_SHASH,
 132                 .cra_blocksize          = SHA1_BLOCK_SIZE,
 133                 .cra_module             = THIS_MODULE,
 134         }
 135 };
 136
 137 static int __init sha1_ce_mod_init(void)
 138 {
 139         if (!(elf_hwcap2 & HWCAP2_SHA1))
 140                 return -ENODEV;
 141         return crypto_register_shash(&alg);
 142 }
 143
 144 static void __exit sha1_ce_mod_fini(void)
 145 {
 146         crypto_unregister_shash(&alg);
 147 }
 148
 149 module_init(sha1_ce_mod_init);
 150 module_exit(sha1_ce_mod_fini);