LXR linux/arch/s390/crypto/sha1

   1/*
   2 * Cryptographic API.
   3 *
   4 * s390 implementation of the SHA1 Secure Hash Algorithm.
   5 *
   6 * Derived from cryptoapi implementation, adapted for in-place
   7 * scatterlist interface.  Originally based on the public domain
   8 * implementation written by Steve Reid.
   9 *
  10 * s390 Version:
  11 *   Copyright IBM Corp. 2003,2007
  12 *   Author(s): Thomas Spatzier
  13 *              Jan Glauber (jan.glauber@de.ibm.com)
  14 *
  15 * Derived from "crypto/sha1_generic.c"
  16 *   Copyright (c) Alan Smithee.
  17 *   Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
  18 *   Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
  19 *
  20 * This program is free software; you can redistribute it and/or modify it
  21 * under the terms of the GNU General Public License as published by the Free
  22 * Software Foundation; either version 2 of the License, or (at your option)
  23 * any later version.
  24 *
  25 */
  26#include <linux/init.h>
  27#include <linux/module.h>
  28#include <linux/crypto.h>
  29#include <crypto/sha.h>
  30
  31#include "crypt_s390.h"
  32
  33struct s390_sha1_ctx {
  34        u64 count;              /* message length */
  35        u32 state[5];
  36        u8 buf[2 * SHA1_BLOCK_SIZE];
  37};
  38
  39static void sha1_init(struct crypto_tfm *tfm)
  40{
  41        struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
  42
  43        sctx->state[0] = SHA1_H0;
  44        sctx->state[1] = SHA1_H1;
  45        sctx->state[2] = SHA1_H2;
  46        sctx->state[3] = SHA1_H3;
  47        sctx->state[4] = SHA1_H4;
  48        sctx->count = 0;
  49}
  50
  51static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
  52                        unsigned int len)
  53{
  54        struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
  55        unsigned int index;
  56        int ret;
  57
  58        /* how much is already in the buffer? */
  59        index = sctx->count & 0x3f;
  60
  61        sctx->count += len;
  62
  63        if (index + len < SHA1_BLOCK_SIZE)
  64                goto store;
  65
  66        /* process one stored block */
  67        if (index) {
  68                memcpy(sctx->buf + index, data, SHA1_BLOCK_SIZE - index);
  69                ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf,
  70                                      SHA1_BLOCK_SIZE);
  71                BUG_ON(ret != SHA1_BLOCK_SIZE);
  72                data += SHA1_BLOCK_SIZE - index;
  73                len -= SHA1_BLOCK_SIZE - index;
  74        }
  75
  76        /* process as many blocks as possible */
  77        if (len >= SHA1_BLOCK_SIZE) {
  78                ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, data,
  79                                      len & ~(SHA1_BLOCK_SIZE - 1));
  80                BUG_ON(ret != (len & ~(SHA1_BLOCK_SIZE - 1)));
  81                data += ret;
  82                len -= ret;
  83        }
  84
  85store:
  86        /* anything left? */
  87        if (len)
  88                memcpy(sctx->buf + index , data, len);
  89}
  90
  91/* Add padding and return the message digest. */
  92static void sha1_final(struct crypto_tfm *tfm, u8 *out)
  93{
  94        struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
  95        u64 bits;
  96        unsigned int index, end;
  97        int ret;
  98
  99        /* must perform manual padding */
 100        index = sctx->count & 0x3f;
 101        end =  (index < 56) ? SHA1_BLOCK_SIZE : (2 * SHA1_BLOCK_SIZE);
 102
 103        /* start pad with 1 */
 104        sctx->buf[index] = 0x80;
 105
 106        /* pad with zeros */
 107        index++;
 108        memset(sctx->buf + index, 0x00, end - index - 8);
 109
 110        /* append message length */
 111        bits = sctx->count * 8;
 112        memcpy(sctx->buf + end - 8, &bits, sizeof(bits));
 113
 114        ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf, end);
 115        BUG_ON(ret != end);
 116
 117        /* copy digest to out */
 118        memcpy(out, sctx->state, SHA1_DIGEST_SIZE);
 119
 120        /* wipe context */
 121        memset(sctx, 0, sizeof *sctx);
 122}
 123
 124static struct crypto_alg alg = {
 125        .cra_name       =       "sha1",
 126        .cra_driver_name=       "sha1-s390",
 127        .cra_priority   =       CRYPT_S390_PRIORITY,
 128        .cra_flags      =       CRYPTO_ALG_TYPE_DIGEST,
 129        .cra_blocksize  =       SHA1_BLOCK_SIZE,
 130        .cra_ctxsize    =       sizeof(struct s390_sha1_ctx),
 131        .cra_module     =       THIS_MODULE,
 132        .cra_list       =       LIST_HEAD_INIT(alg.cra_list),
 133        .cra_u          =       { .digest = {
 134        .dia_digestsize =       SHA1_DIGEST_SIZE,
 135        .dia_init       =       sha1_init,
 136        .dia_update     =       sha1_update,
 137        .dia_final      =       sha1_final } }
 138};
 139
 140static int __init init(void)
 141{
 142        if (!crypt_s390_func_available(KIMD_SHA_1))
 143                return -EOPNOTSUPP;
 144
 145        return crypto_register_alg(&alg);
 146}
 147
 148static void __exit fini(void)
 149{
 150        crypto_unregister_alg(&alg);
 151}
 152
 153module_init(init);
 154module_exit(fini);
 155
 156MODULE_ALIAS("sha1");
 157
 158MODULE_LICENSE("GPL");
 159MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
 160