arch/s390/crypto/sha_common.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Cryptographic API.
   4  *
   5  * s390 generic implementation of the SHA Secure Hash Algorithms.
   6  *
   7  * Copyright IBM Corp. 2007
   8  * Author(s): Jan Glauber (jang@de.ibm.com)
   9  */
  10
  11 #include <crypto/internal/hash.h>
  12 #include <linux/module.h>
  13 #include <asm/cpacf.h>
  14 #include "sha.h"
  15
  16 int s390_sha_update(struct shash_desc *desc, const u8 *data, unsigned int len)
  17 {
  18         struct s390_sha_ctx *ctx = shash_desc_ctx(desc);
  19         unsigned int bsize = crypto_shash_blocksize(desc->tfm);
  20         unsigned int index, n;
  21
  22         /* how much is already in the buffer? */
  23         index = ctx->count & (bsize - 1);
  24         ctx->count += len;
  25
  26         if ((index + len) < bsize)
  27                 goto store;
  28
  29         /* process one stored block */
  30         if (index) {
  31                 memcpy(ctx->buf + index, data, bsize - index);
  32                 cpacf_kimd(ctx->func, ctx->state, ctx->buf, bsize);
  33                 data += bsize - index;
  34                 len -= bsize - index;
  35                 index = 0;
  36         }
  37
  38         /* process as many blocks as possible */
  39         if (len >= bsize) {
  40                 n = len & ~(bsize - 1);
  41                 cpacf_kimd(ctx->func, ctx->state, data, n);
  42                 data += n;
  43                 len -= n;
  44         }
  45 store:
  46         if (len)
  47                 memcpy(ctx->buf + index , data, len);
  48
  49         return 0;
  50 }
  51 EXPORT_SYMBOL_GPL(s390_sha_update);
  52
  53 int s390_sha_final(struct shash_desc *desc, u8 *out)
  54 {
  55         struct s390_sha_ctx *ctx = shash_desc_ctx(desc);
  56         unsigned int bsize = crypto_shash_blocksize(desc->tfm);
  57         u64 bits;
  58         unsigned int index, end, plen;
  59
  60         /* SHA-512 uses 128 bit padding length */
  61         plen = (bsize > SHA256_BLOCK_SIZE) ? 16 : 8;
  62
  63         /* must perform manual padding */
  64         index = ctx->count & (bsize - 1);
  65         end = (index < bsize - plen) ? bsize : (2 * bsize);
  66
  67         /* start pad with 1 */
  68         ctx->buf[index] = 0x80;
  69         index++;
  70
  71         /* pad with zeros */
  72         memset(ctx->buf + index, 0x00, end - index - 8);
  73
  74         /*
  75          * Append message length. Well, SHA-512 wants a 128 bit length value,
  76          * nevertheless we use u64, should be enough for now...
  77          */
  78         bits = ctx->count * 8;
  79         memcpy(ctx->buf + end - 8, &bits, sizeof(bits));
  80         cpacf_kimd(ctx->func, ctx->state, ctx->buf, end);
  81
  82         /* copy digest to out */
  83         memcpy(out, ctx->state, crypto_shash_digestsize(desc->tfm));
  84         /* wipe context */
  85         memset(ctx, 0, sizeof *ctx);
  86
  87         return 0;
  88 }
  89 EXPORT_SYMBOL_GPL(s390_sha_final);
  90
  91 MODULE_LICENSE("GPL");
  92 MODULE_DESCRIPTION("s390 SHA cipher common functions");