LXR linux/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
  29extern void powerpc_sha_transform(u32 *state, const u8 *src, u32 *temp);
  30
  31static 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
  42static 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                memset(temp, 0, 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. */
  79static 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
 107static 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
 115static 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
 123static 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
 141static int __init sha1_powerpc_mod_init(void)
 142{
 143        return crypto_register_shash(&alg);
 144}
 145
 146static void __exit sha1_powerpc_mod_fini(void)
 147{
 148        crypto_unregister_shash(&alg);
 149}
 150
 151module_init(sha1_powerpc_mod_init);
 152module_exit(sha1_powerpc_mod_fini);
 153
 154MODULE_LICENSE("GPL");
 155MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
 156
 157MODULE_ALIAS("sha1-powerpc");
 158