include/crypto/sm3_base.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * sm3_base.h - core logic for SM3 implementations
   4  *
   5  * Copyright (C) 2017 ARM Limited or its affiliates.
   6  * Written by Gilad Ben-Yossef <gilad@benyossef.com>
   7  */
   8
   9 #include <crypto/internal/hash.h>
  10 #include <crypto/sm3.h>
  11 #include <linux/crypto.h>
  12 #include <linux/module.h>
  13 #include <asm/unaligned.h>
  14
  15 typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks);
  16
  17 static inline int sm3_base_init(struct shash_desc *desc)
  18 {
  19         struct sm3_state *sctx = shash_desc_ctx(desc);
  20
  21         sctx->state[0] = SM3_IVA;
  22         sctx->state[1] = SM3_IVB;
  23         sctx->state[2] = SM3_IVC;
  24         sctx->state[3] = SM3_IVD;
  25         sctx->state[4] = SM3_IVE;
  26         sctx->state[5] = SM3_IVF;
  27         sctx->state[6] = SM3_IVG;
  28         sctx->state[7] = SM3_IVH;
  29         sctx->count = 0;
  30
  31         return 0;
  32 }
  33
  34 static inline int sm3_base_do_update(struct shash_desc *desc,
  35                                       const u8 *data,
  36                                       unsigned int len,
  37                                       sm3_block_fn *block_fn)
  38 {
  39         struct sm3_state *sctx = shash_desc_ctx(desc);
  40         unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
  41
  42         sctx->count += len;
  43
  44         if (unlikely((partial + len) >= SM3_BLOCK_SIZE)) {
  45                 int blocks;
  46
  47                 if (partial) {
  48                         int p = SM3_BLOCK_SIZE - partial;
  49
  50                         memcpy(sctx->buffer + partial, data, p);
  51                         data += p;
  52                         len -= p;
  53
  54                         block_fn(sctx, sctx->buffer, 1);
  55                 }
  56
  57                 blocks = len / SM3_BLOCK_SIZE;
  58                 len %= SM3_BLOCK_SIZE;
  59
  60                 if (blocks) {
  61                         block_fn(sctx, data, blocks);
  62                         data += blocks * SM3_BLOCK_SIZE;
  63                 }
  64                 partial = 0;
  65         }
  66         if (len)
  67                 memcpy(sctx->buffer + partial, data, len);
  68
  69         return 0;
  70 }
  71
  72 static inline int sm3_base_do_finalize(struct shash_desc *desc,
  73                                         sm3_block_fn *block_fn)
  74 {
  75         const int bit_offset = SM3_BLOCK_SIZE - sizeof(__be64);
  76         struct sm3_state *sctx = shash_desc_ctx(desc);
  77         __be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
  78         unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
  79
  80         sctx->buffer[partial++] = 0x80;
  81         if (partial > bit_offset) {
  82                 memset(sctx->buffer + partial, 0x0, SM3_BLOCK_SIZE - partial);
  83                 partial = 0;
  84
  85                 block_fn(sctx, sctx->buffer, 1);
  86         }
  87
  88         memset(sctx->buffer + partial, 0x0, bit_offset - partial);
  89         *bits = cpu_to_be64(sctx->count << 3);
  90         block_fn(sctx, sctx->buffer, 1);
  91
  92         return 0;
  93 }
  94
  95 static inline int sm3_base_finish(struct shash_desc *desc, u8 *out)
  96 {
  97         struct sm3_state *sctx = shash_desc_ctx(desc);
  98         __be32 *digest = (__be32 *)out;
  99         int i;
 100
 101         for (i = 0; i < SM3_DIGEST_SIZE / sizeof(__be32); i++)
 102                 put_unaligned_be32(sctx->state[i], digest++);
 103
 104         *sctx = (struct sm3_state){};
 105         return 0;
 106 }