arch/s390/crypto/sha1_s390.c

   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.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
  30 #include "crypt_s390.h"
  31
  32 #define SHA1_DIGEST_SIZE        20
  33 #define SHA1_BLOCK_SIZE         64
  34
  35 struct s390_sha1_ctx {
  36         u64 count;              /* message length */
  37         u32 state[5];
  38         u8 buf[2 * SHA1_BLOCK_SIZE];
  39 };
  40
  41 static void sha1_init(struct crypto_tfm *tfm)
  42 {
  43         struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
  44
  45         sctx->state[0] = 0x67452301;
  46         sctx->state[1] = 0xEFCDAB89;
  47         sctx->state[2] = 0x98BADCFE;
  48         sctx->state[3] = 0x10325476;
  49         sctx->state[4] = 0xC3D2E1F0;
  50         sctx->count = 0;
  51 }
  52
  53 static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
  54                         unsigned int len)
  55 {
  56         struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
  57         unsigned int index;
  58         int ret;
  59
  60         /* how much is already in the buffer? */
  61         index = sctx->count & 0x3f;
  62
  63         sctx->count += len;
  64
  65         if (index + len < SHA1_BLOCK_SIZE)
  66                 goto store;
  67
  68         /* process one stored block */
  69         if (index) {
  70                 memcpy(sctx->buf + index, data, SHA1_BLOCK_SIZE - index);
  71                 ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf,
  72                                       SHA1_BLOCK_SIZE);
  73                 BUG_ON(ret != SHA1_BLOCK_SIZE);
  74                 data += SHA1_BLOCK_SIZE - index;
  75                 len -= SHA1_BLOCK_SIZE - index;
  76         }
  77
  78         /* process as many blocks as possible */
  79         if (len >= SHA1_BLOCK_SIZE) {
  80                 ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, data,
  81                                       len & ~(SHA1_BLOCK_SIZE - 1));
  82                 BUG_ON(ret != (len & ~(SHA1_BLOCK_SIZE - 1)));
  83                 data += ret;
  84                 len -= ret;
  85         }
  86
  87 store:
  88         /* anything left? */
  89         if (len)
  90                 memcpy(sctx->buf + index , data, len);
  91 }
  92
  93 /* Add padding and return the message digest. */
  94 static void sha1_final(struct crypto_tfm *tfm, u8 *out)
  95 {
  96         struct s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
  97         u64 bits;
  98         unsigned int index, end;
  99         int ret;
 100
 101         /* must perform manual padding */
 102         index = sctx->count & 0x3f;
 103         end =  (index < 56) ? SHA1_BLOCK_SIZE : (2 * SHA1_BLOCK_SIZE);
 104
 105         /* start pad with 1 */
 106         sctx->buf[index] = 0x80;
 107
 108         /* pad with zeros */
 109         index++;
 110         memset(sctx->buf + index, 0x00, end - index - 8);
 111
 112         /* append message length */
 113         bits = sctx->count * 8;
 114         memcpy(sctx->buf + end - 8, &bits, sizeof(bits));
 115
 116         ret = crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buf, end);
 117         BUG_ON(ret != end);
 118
 119         /* copy digest to out */
 120         memcpy(out, sctx->state, SHA1_DIGEST_SIZE);
 121
 122         /* wipe context */
 123         memset(sctx, 0, sizeof *sctx);
 124 }
 125
 126 static struct crypto_alg alg = {
 127         .cra_name       =       "sha1",
 128         .cra_driver_name=       "sha1-s390",
 129         .cra_priority   =       CRYPT_S390_PRIORITY,
 130         .cra_flags      =       CRYPTO_ALG_TYPE_DIGEST,
 131         .cra_blocksize  =       SHA1_BLOCK_SIZE,
 132         .cra_ctxsize    =       sizeof(struct s390_sha1_ctx),
 133         .cra_module     =       THIS_MODULE,
 134         .cra_list       =       LIST_HEAD_INIT(alg.cra_list),
 135         .cra_u          =       { .digest = {
 136         .dia_digestsize =       SHA1_DIGEST_SIZE,
 137         .dia_init       =       sha1_init,
 138         .dia_update     =       sha1_update,
 139         .dia_final      =       sha1_final } }
 140 };
 141
 142 static int __init init(void)
 143 {
 144         if (!crypt_s390_func_available(KIMD_SHA_1))
 145                 return -EOPNOTSUPP;
 146
 147         return crypto_register_alg(&alg);
 148 }
 149
 150 static void __exit fini(void)
 151 {
 152         crypto_unregister_alg(&alg);
 153 }
 154
 155 module_init(init);
 156 module_exit(fini);
 157
 158 MODULE_ALIAS("sha1");
 159
 160 MODULE_LICENSE("GPL");
 161 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");