1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * sha256_base.h - core logic for SHA-256 implementations 4 * 5 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org> 6 */ 7 8 #ifndef _CRYPTO_SHA256_BASE_H 9 #define _CRYPTO_SHA256_BASE_H 10 11 #include <crypto/internal/hash.h> 12 #include <crypto/sha2.h> 13 #include <linux/crypto.h> 14 #include <linux/module.h> 15 #include <linux/string.h> 16 17 #include <asm/unaligned.h> 18 19 typedef void (sha256_block_fn)(struct sha256_state *sst, u8 const *src, 20 int blocks); 21 22 static inline int sha224_base_init(struct shash_desc *desc) 23 { 24 struct sha256_state *sctx = shash_desc_ctx(desc); 25 26 sha224_init(sctx); 27 return 0; 28 } 29 30 static inline int sha256_base_init(struct shash_desc *desc) 31 { 32 struct sha256_state *sctx = shash_desc_ctx(desc); 33 34 sha256_init(sctx); 35 return 0; 36 } 37 38 static inline int sha256_base_do_update(struct shash_desc *desc, 39 const u8 *data, 40 unsigned int len, 41 sha256_block_fn *block_fn) 42 { 43 struct sha256_state *sctx = shash_desc_ctx(desc); 44 unsigned int partial = sctx->count % SHA256_BLOCK_SIZE; 45 46 sctx->count += len; 47 48 if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) { 49 int blocks; 50 51 if (partial) { 52 int p = SHA256_BLOCK_SIZE - partial; 53 54 memcpy(sctx->buf + partial, data, p); 55 data += p; 56 len -= p; 57 58 block_fn(sctx, sctx->buf, 1); 59 } 60 61 blocks = len / SHA256_BLOCK_SIZE; 62 len %= SHA256_BLOCK_SIZE; 63 64 if (blocks) { 65 block_fn(sctx, data, blocks); 66 data += blocks * SHA256_BLOCK_SIZE; 67 } 68 partial = 0; 69 } 70 if (len) 71 memcpy(sctx->buf + partial, data, len); 72 73 return 0; 74 } 75 76 static inline int sha256_base_do_finalize(struct shash_desc *desc, 77 sha256_block_fn *block_fn) 78 { 79 const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64); 80 struct sha256_state *sctx = shash_desc_ctx(desc); 81 __be64 *bits = (__be64 *)(sctx->buf + bit_offset); 82 unsigned int partial = sctx->count % SHA256_BLOCK_SIZE; 83 84 sctx->buf[partial++] = 0x80; 85 if (partial > bit_offset) { 86 memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial); 87 partial = 0; 88 89 block_fn(sctx, sctx->buf, 1); 90 } 91 92 memset(sctx->buf + partial, 0x0, bit_offset - partial); 93 *bits = cpu_to_be64(sctx->count << 3); 94 block_fn(sctx, sctx->buf, 1); 95 96 return 0; 97 } 98 99 static inline int sha256_base_finish(struct shash_desc *desc, u8 *out) 100 { 101 unsigned int digest_size = crypto_shash_digestsize(desc->tfm); 102 struct sha256_state *sctx = shash_desc_ctx(desc); 103 __be32 *digest = (__be32 *)out; 104 int i; 105 106 for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32)) 107 put_unaligned_be32(sctx->state[i], digest++); 108 109 memzero_explicit(sctx, sizeof(*sctx)); 110 return 0; 111 } 112 113 #endif /* _CRYPTO_SHA256_BASE_H */ 114