arch/powerpc/crypto/sha1.c

   1 /*
   2  * Cryptographic API.
   3  *
   4  * powerpc implementation of the SHA1 Secure Hash Algorithm.
   5  *
   6  * Derived from cryptoapi implementation, adapted for in-place
   7  * scatterlist interface.
   8  *
   9  * Derived from "crypto/sha1.c"
  10  * Copyright (c) Alan Smithee.
  11  * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
  12  * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
  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 #include <crypto/internal/hash.h>
  21 #include <linux/init.h>
  22 #include <linux/module.h>
  23 #include <linux/mm.h>
  24 #include <linux/cryptohash.h>
  25 #include <linux/types.h>
  26 #include <crypto/sha.h>
  27 #include <asm/byteorder.h>
  28
  29 extern void powerpc_sha_transform(u32 *state, const u8 *src, u32 *temp);
  30
  31 static int sha1_init(struct shash_desc *desc)
  32 {
  33         struct sha1_state *sctx = shash_desc_ctx(desc);
  34
  35         *sctx = (struct sha1_state){
  36                 .state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
  37         };
  38
  39         return 0;
  40 }
  41
  42 static int sha1_update(struct shash_desc *desc, const u8 *data,
  43                         unsigned int len)
  44 {
  45         struct sha1_state *sctx = shash_desc_ctx(desc);
  46         unsigned int partial, done;
  47         const u8 *src;
  48
  49         partial = sctx->count & 0x3f;
  50         sctx->count += len;
  51         done = 0;
  52         src = data;
  53
  54         if ((partial + len) > 63) {
  55                 u32 temp[SHA_WORKSPACE_WORDS];
  56
  57                 if (partial) {
  58                         done = -partial;
  59                         memcpy(sctx->buffer + partial, data, done + 64);
  60                         src = sctx->buffer;
  61                 }
  62
  63                 do {
  64                         powerpc_sha_transform(sctx->state, src, temp);
  65                         done += 64;
  66                         src = data + done;
  67                 } while (done + 63 < len);
  68
  69                 memzero_explicit(temp, sizeof(temp));
  70                 partial = 0;
  71         }
  72         memcpy(sctx->buffer + partial, src, len - done);
  73
  74         return 0;
  75 }
  76
  77
  78 /* Add padding and return the message digest. */
  79 static int sha1_final(struct shash_desc *desc, u8 *out)
  80 {
  81         struct sha1_state *sctx = shash_desc_ctx(desc);
  82         __be32 *dst = (__be32 *)out;
  83         u32 i, index, padlen;
  84         __be64 bits;
  85         static const u8 padding[64] = { 0x80, };
  86
  87         bits = cpu_to_be64(sctx->count << 3);
  88
  89         /* Pad out to 56 mod 64 */
  90         index = sctx->count & 0x3f;
  91         padlen = (index < 56) ? (56 - index) : ((64+56) - index);
  92         sha1_update(desc, padding, padlen);
  93
  94         /* Append length */
  95         sha1_update(desc, (const u8 *)&bits, sizeof(bits));
  96
  97         /* Store state in digest */
  98         for (i = 0; i < 5; i++)
  99                 dst[i] = cpu_to_be32(sctx->state[i]);
 100
 101         /* Wipe context */
 102         memset(sctx, 0, sizeof *sctx);
 103
 104         return 0;
 105 }
 106
 107 static int sha1_export(struct shash_desc *desc, void *out)
 108 {
 109         struct sha1_state *sctx = shash_desc_ctx(desc);
 110
 111         memcpy(out, sctx, sizeof(*sctx));
 112         return 0;
 113 }
 114
 115 static int sha1_import(struct shash_desc *desc, const void *in)
 116 {
 117         struct sha1_state *sctx = shash_desc_ctx(desc);
 118
 119         memcpy(sctx, in, sizeof(*sctx));
 120         return 0;
 121 }
 122
 123 static struct shash_alg alg = {
 124         .digestsize     =       SHA1_DIGEST_SIZE,
 125         .init           =       sha1_init,
 126         .update         =       sha1_update,
 127         .final          =       sha1_final,
 128         .export         =       sha1_export,
 129         .import         =       sha1_import,
 130         .descsize       =       sizeof(struct sha1_state),
 131         .statesize      =       sizeof(struct sha1_state),
 132         .base           =       {
 133                 .cra_name       =       "sha1",
 134                 .cra_driver_name=       "sha1-powerpc",
 135                 .cra_flags      =       CRYPTO_ALG_TYPE_SHASH,
 136                 .cra_blocksize  =       SHA1_BLOCK_SIZE,
 137                 .cra_module     =       THIS_MODULE,
 138         }
 139 };
 140
 141 static int __init sha1_powerpc_mod_init(void)
 142 {
 143         return crypto_register_shash(&alg);
 144 }
 145
 146 static void __exit sha1_powerpc_mod_fini(void)
 147 {
 148         crypto_unregister_shash(&alg);
 149 }
 150
 151 module_init(sha1_powerpc_mod_init);
 152 module_exit(sha1_powerpc_mod_fini);
 153
 154 MODULE_LICENSE("GPL");
 155 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
 156
 157 MODULE_ALIAS_CRYPTO("sha1");
 158 MODULE_ALIAS_CRYPTO("sha1-powerpc");