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