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