arch/s390/crypto/sha1_z990.c

   1 /*
   2  * Cryptographic API.
   3  *
   4  * z990 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 (C) 2003 IBM Deutschland GmbH, IBM Corporation
  12  *   Author(s): Thomas Spatzier (tspat@de.ibm.com)
  13  *
  14  * Derived from "crypto/sha1.c"
  15  *   Copyright (c) Alan Smithee.
  16  *   Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
  17  *   Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
  18  *
  19  * This program is free software; you can redistribute it and/or modify it
  20  * under the terms of the GNU General Public License as published by the Free
  21  * Software Foundation; either version 2 of the License, or (at your option)
  22  * any later version.
  23  *
  24  */
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/mm.h>
  28 #include <linux/crypto.h>
  29 #include <asm/scatterlist.h>
  30 #include <asm/byteorder.h>
  31 #include "crypt_z990.h"
  32
  33 #define SHA1_DIGEST_SIZE        20
  34 #define SHA1_BLOCK_SIZE         64
  35
  36 struct crypt_z990_sha1_ctx {
  37         u64 count;
  38         u32 state[5];
  39         u32 buf_len;
  40         u8 buffer[2 * SHA1_BLOCK_SIZE];
  41 };
  42
  43 static void
  44 sha1_init(void *ctx)
  45 {
  46         static const struct crypt_z990_sha1_ctx initstate = {
  47                 .state = {
  48                         0x67452301,
  49                         0xEFCDAB89,
  50                         0x98BADCFE,
  51                         0x10325476,
  52                         0xC3D2E1F0
  53                 },
  54         };
  55         memcpy(ctx, &initstate, sizeof(initstate));
  56 }
  57
  58 static void
  59 sha1_update(void *ctx, const u8 *data, unsigned int len)
  60 {
  61         struct crypt_z990_sha1_ctx *sctx;
  62         long imd_len;
  63
  64         sctx = ctx;
  65         sctx->count += len * 8; //message bit length
  66
  67         //anything in buffer yet? -> must be completed
  68         if (sctx->buf_len && (sctx->buf_len + len) >= SHA1_BLOCK_SIZE) {
  69                 //complete full block and hash
  70                 memcpy(sctx->buffer + sctx->buf_len, data,
  71                                 SHA1_BLOCK_SIZE - sctx->buf_len);
  72                 crypt_z990_kimd(KIMD_SHA_1, sctx->state, sctx->buffer,
  73                                 SHA1_BLOCK_SIZE);
  74                 data += SHA1_BLOCK_SIZE - sctx->buf_len;
  75                 len -= SHA1_BLOCK_SIZE - sctx->buf_len;
  76                 sctx->buf_len = 0;
  77         }
  78
  79         //rest of data contains full blocks?
  80         imd_len = len & ~0x3ful;
  81         if (imd_len){
  82                 crypt_z990_kimd(KIMD_SHA_1, sctx->state, data, imd_len);
  83                 data += imd_len;
  84                 len -= imd_len;
  85         }
  86         //anything left? store in buffer
  87         if (len){
  88                 memcpy(sctx->buffer + sctx->buf_len , data, len);
  89                 sctx->buf_len += len;
  90         }
  91 }
  92
  93
  94 static void
  95 pad_message(struct crypt_z990_sha1_ctx* sctx)
  96 {
  97         int index;
  98
  99         index = sctx->buf_len;
 100         sctx->buf_len = (sctx->buf_len < 56)?
 101                 SHA1_BLOCK_SIZE:2 * SHA1_BLOCK_SIZE;
 102         //start pad with 1
 103         sctx->buffer[index] = 0x80;
 104         //pad with zeros
 105         index++;
 106         memset(sctx->buffer + index, 0x00, sctx->buf_len - index);
 107         //append length
 108         memcpy(sctx->buffer + sctx->buf_len - 8, &sctx->count,
 109                         sizeof sctx->count);
 110 }
 111
 112 /* Add padding and return the message digest. */
 113 static void
 114 sha1_final(void* ctx, u8 *out)
 115 {
 116         struct crypt_z990_sha1_ctx *sctx = ctx;
 117
 118         //must perform manual padding
 119         pad_message(sctx);
 120         crypt_z990_kimd(KIMD_SHA_1, sctx->state, sctx->buffer, sctx->buf_len);
 121         //copy digest to out
 122         memcpy(out, sctx->state, SHA1_DIGEST_SIZE);
 123         /* Wipe context */
 124         memset(sctx, 0, sizeof *sctx);
 125 }
 126
 127 static struct crypto_alg alg = {
 128         .cra_name       =       "sha1",
 129         .cra_flags      =       CRYPTO_ALG_TYPE_DIGEST,
 130         .cra_blocksize  =       SHA1_BLOCK_SIZE,
 131         .cra_ctxsize    =       sizeof(struct crypt_z990_sha1_ctx),
 132         .cra_module     =       THIS_MODULE,
 133         .cra_list       =       LIST_HEAD_INIT(alg.cra_list),
 134         .cra_u          =       { .digest = {
 135         .dia_digestsize =       SHA1_DIGEST_SIZE,
 136         .dia_init       =       sha1_init,
 137         .dia_update     =       sha1_update,
 138         .dia_final      =       sha1_final } }
 139 };
 140
 141 static int
 142 init(void)
 143 {
 144         int ret = -ENOSYS;
 145
 146         if (crypt_z990_func_available(KIMD_SHA_1)){
 147                 ret = crypto_register_alg(&alg);
 148                 if (ret == 0){
 149                         printk(KERN_INFO "crypt_z990: sha1_z990 loaded.\n");
 150                 }
 151         }
 152         return ret;
 153 }
 154
 155 static void __exit
 156 fini(void)
 157 {
 158         crypto_unregister_alg(&alg);
 159 }
 160
 161 module_init(init);
 162 module_exit(fini);
 163
 164 MODULE_ALIAS("sha1");
 165
 166 MODULE_LICENSE("GPL");
 167 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");