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_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
  33 struct s390_sha1_ctx {
  34         u64 count;              /* message length */
  35         u32 state[5];
  36         u8 buf[2 * SHA1_BLOCK_SIZE];
  37 };
  38
  39 static 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
  51 static 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
  85 store:
  86         /* anything left? */
  87         if (len)
  88                 memcpy(sctx->buf + index , data, len);
  89 }
  90
  91 /* Add padding and return the message digest. */
  92 static 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
 124 static 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
 140 static 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
 148 static void __exit fini(void)
 149 {
 150         crypto_unregister_alg(&alg);
 151 }
 152
 153 module_init(init);
 154 module_exit(fini);
 155
 156 MODULE_ALIAS("sha1");
 157
 158 MODULE_LICENSE("GPL");
 159 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");