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/mm.h>
  29 #include <linux/crypto.h>
  30 #include <asm/scatterlist.h>
  31 #include <asm/byteorder.h>
  32 #include "crypt_s390.h"
  33
  34 #define SHA1_DIGEST_SIZE        20
  35 #define SHA1_BLOCK_SIZE         64
  36
  37 struct crypt_s390_sha1_ctx {
  38         u64 count;
  39         u32 state[5];
  40         u32 buf_len;
  41         u8 buffer[2 * SHA1_BLOCK_SIZE];
  42 };
  43
  44 static void sha1_init(struct crypto_tfm *tfm)
  45 {
  46         struct crypt_s390_sha1_ctx *ctx = crypto_tfm_ctx(tfm);
  47
  48         ctx->state[0] = 0x67452301;
  49         ctx->state[1] = 0xEFCDAB89;
  50         ctx->state[2] = 0x98BADCFE;
  51         ctx->state[3] = 0x10325476;
  52         ctx->state[4] = 0xC3D2E1F0;
  53
  54         ctx->count = 0;
  55         ctx->buf_len = 0;
  56 }
  57
  58 static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
  59                         unsigned int len)
  60 {
  61         struct crypt_s390_sha1_ctx *sctx;
  62         long imd_len;
  63
  64         sctx = crypto_tfm_ctx(tfm);
  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_s390_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_s390_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 pad_message(struct crypt_s390_sha1_ctx* sctx)
  95 {
  96         int index;
  97
  98         index = sctx->buf_len;
  99         sctx->buf_len = (sctx->buf_len < 56) ?
 100                          SHA1_BLOCK_SIZE:2 * SHA1_BLOCK_SIZE;
 101         /* start pad with 1 */
 102         sctx->buffer[index] = 0x80;
 103         /* pad with zeros */
 104         index++;
 105         memset(sctx->buffer + index, 0x00, sctx->buf_len - index);
 106         /* append length */
 107         memcpy(sctx->buffer + sctx->buf_len - 8, &sctx->count,
 108                sizeof sctx->count);
 109 }
 110
 111 /* Add padding and return the message digest. */
 112 static void sha1_final(struct crypto_tfm *tfm, u8 *out)
 113 {
 114         struct crypt_s390_sha1_ctx *sctx = crypto_tfm_ctx(tfm);
 115
 116         /* must perform manual padding */
 117         pad_message(sctx);
 118         crypt_s390_kimd(KIMD_SHA_1, sctx->state, sctx->buffer, sctx->buf_len);
 119         /* copy digest to out */
 120         memcpy(out, sctx->state, SHA1_DIGEST_SIZE);
 121         /* wipe context */
 122         memset(sctx, 0, sizeof *sctx);
 123 }
 124
 125 static struct crypto_alg alg = {
 126         .cra_name       =       "sha1",
 127         .cra_driver_name=       "sha1-s390",
 128         .cra_priority   =       CRYPT_S390_PRIORITY,
 129         .cra_flags      =       CRYPTO_ALG_TYPE_DIGEST,
 130         .cra_blocksize  =       SHA1_BLOCK_SIZE,
 131         .cra_ctxsize    =       sizeof(struct crypt_s390_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 __init init(void)
 142 {
 143         if (!crypt_s390_func_available(KIMD_SHA_1))
 144                 return -EOPNOTSUPP;
 145
 146         return crypto_register_alg(&alg);
 147 }
 148
 149 static void __exit fini(void)
 150 {
 151         crypto_unregister_alg(&alg);
 152 }
 153
 154 module_init(init);
 155 module_exit(fini);
 156
 157 MODULE_ALIAS("sha1");
 158
 159 MODULE_LICENSE("GPL");
 160 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");