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 #ifndef _CRYPTO_SM3_BASE_H
  10 #define _CRYPTO_SM3_BASE_H
  11
  12 #include <crypto/internal/hash.h>
  13 #include <crypto/sm3.h>
  14 #include <linux/crypto.h>
  15 #include <linux/module.h>
  16 #include <linux/string.h>
  17 #include <linux/unaligned.h>
  18
  19 typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks);
  20
  21 static inline int sm3_base_init(struct shash_desc *desc)
  22 {
  23         struct sm3_state *sctx = shash_desc_ctx(desc);
  24
  25         sctx->state[0] = SM3_IVA;
  26         sctx->state[1] = SM3_IVB;
  27         sctx->state[2] = SM3_IVC;
  28         sctx->state[3] = SM3_IVD;
  29         sctx->state[4] = SM3_IVE;
  30         sctx->state[5] = SM3_IVF;
  31         sctx->state[6] = SM3_IVG;
  32         sctx->state[7] = SM3_IVH;
  33         sctx->count = 0;
  34
  35         return 0;
  36 }
  37
  38 static inline int sm3_base_do_update(struct shash_desc *desc,
  39                                       const u8 *data,
  40                                       unsigned int len,
  41                                       sm3_block_fn *block_fn)
  42 {
  43         struct sm3_state *sctx = shash_desc_ctx(desc);
  44         unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
  45
  46         sctx->count += len;
  47
  48         if (unlikely((partial + len) >= SM3_BLOCK_SIZE)) {
  49                 int blocks;
  50
  51                 if (partial) {
  52                         int p = SM3_BLOCK_SIZE - partial;
  53
  54                         memcpy(sctx->buffer + partial, data, p);
  55                         data += p;
  56                         len -= p;
  57
  58                         block_fn(sctx, sctx->buffer, 1);
  59                 }
  60
  61                 blocks = len / SM3_BLOCK_SIZE;
  62                 len %= SM3_BLOCK_SIZE;
  63
  64                 if (blocks) {
  65                         block_fn(sctx, data, blocks);
  66                         data += blocks * SM3_BLOCK_SIZE;
  67                 }
  68                 partial = 0;
  69         }
  70         if (len)
  71                 memcpy(sctx->buffer + partial, data, len);
  72
  73         return 0;
  74 }
  75
  76 static inline int sm3_base_do_finalize(struct shash_desc *desc,
  77                                         sm3_block_fn *block_fn)
  78 {
  79         const int bit_offset = SM3_BLOCK_SIZE - sizeof(__be64);
  80         struct sm3_state *sctx = shash_desc_ctx(desc);
  81         __be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
  82         unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
  83
  84         sctx->buffer[partial++] = 0x80;
  85         if (partial > bit_offset) {
  86                 memset(sctx->buffer + partial, 0x0, SM3_BLOCK_SIZE - partial);
  87                 partial = 0;
  88
  89                 block_fn(sctx, sctx->buffer, 1);
  90         }
  91
  92         memset(sctx->buffer + partial, 0x0, bit_offset - partial);
  93         *bits = cpu_to_be64(sctx->count << 3);
  94         block_fn(sctx, sctx->buffer, 1);
  95
  96         return 0;
  97 }
  98
  99 static inline int sm3_base_finish(struct shash_desc *desc, u8 *out)
 100 {
 101         struct sm3_state *sctx = shash_desc_ctx(desc);
 102         __be32 *digest = (__be32 *)out;
 103         int i;
 104
 105         for (i = 0; i < SM3_DIGEST_SIZE / sizeof(__be32); i++)
 106                 put_unaligned_be32(sctx->state[i], digest++);
 107
 108         memzero_explicit(sctx, sizeof(*sctx));
 109         return 0;
 110 }
 111
 112 #endif /* _CRYPTO_SM3_BASE_H */