1 /*===-- llvm-c/blake3.h - BLAKE3 C Interface ----------------------*- C -*-===*\
2 |*                                                                            *|
3 |* Released into the public domain with CC0 1.0                               *|
4 |* See 'llvm/lib/Support/BLAKE3/LICENSE' for info.                            *|
5 |* SPDX-License-Identifier: CC0-1.0                                           *|
6 |*                                                                            *|
7 |*===----------------------------------------------------------------------===*|
8 |*                                                                            *|
9 |* This header declares the C interface to LLVM's BLAKE3 implementation.      *|
10 |* Original BLAKE3 C API: https://github.com/BLAKE3-team/BLAKE3/tree/1.3.1/c  *|
11 |*                                                                            *|
12 |* Symbols are prefixed with 'llvm' to avoid a potential conflict with        *|
13 |* another BLAKE3 version within the same program.                            *|
14 |*                                                                            *|
15 \*===----------------------------------------------------------------------===*/
16 
17 #ifndef LLVM_C_BLAKE3_H
18 #define LLVM_C_BLAKE3_H
19 
20 #include <stddef.h>
21 #include <stdint.h>
22 
23 #ifdef __cplusplus
24 extern "C" {
25 #endif
26 
27 #define LLVM_BLAKE3_VERSION_STRING "1.3.1"
28 #define LLVM_BLAKE3_KEY_LEN 32
29 #define LLVM_BLAKE3_OUT_LEN 32
30 #define LLVM_BLAKE3_BLOCK_LEN 64
31 #define LLVM_BLAKE3_CHUNK_LEN 1024
32 #define LLVM_BLAKE3_MAX_DEPTH 54
33 
34 // This struct is a private implementation detail. It has to be here because
35 // it's part of llvm_blake3_hasher below.
36 typedef struct {
37   uint32_t cv[8];
38   uint64_t chunk_counter;
39   uint8_t buf[LLVM_BLAKE3_BLOCK_LEN];
40   uint8_t buf_len;
41   uint8_t blocks_compressed;
42   uint8_t flags;
43 } llvm_blake3_chunk_state;
44 
45 typedef struct {
46   uint32_t key[8];
47   llvm_blake3_chunk_state chunk;
48   uint8_t cv_stack_len;
49   // The stack size is MAX_DEPTH + 1 because we do lazy merging. For example,
50   // with 7 chunks, we have 3 entries in the stack. Adding an 8th chunk
51   // requires a 4th entry, rather than merging everything down to 1, because we
52   // don't know whether more input is coming. This is different from how the
53   // reference implementation does things.
54   uint8_t cv_stack[(LLVM_BLAKE3_MAX_DEPTH + 1) * LLVM_BLAKE3_OUT_LEN];
55 } llvm_blake3_hasher;
56 
57 const char *llvm_blake3_version(void);
58 void llvm_blake3_hasher_init(llvm_blake3_hasher *self);
59 void llvm_blake3_hasher_init_keyed(llvm_blake3_hasher *self,
60                                    const uint8_t key[LLVM_BLAKE3_KEY_LEN]);
61 void llvm_blake3_hasher_init_derive_key(llvm_blake3_hasher *self,
62                                         const char *context);
63 void llvm_blake3_hasher_init_derive_key_raw(llvm_blake3_hasher *self,
64                                             const void *context,
65                                             size_t context_len);
66 void llvm_blake3_hasher_update(llvm_blake3_hasher *self, const void *input,
67                                size_t input_len);
68 void llvm_blake3_hasher_finalize(const llvm_blake3_hasher *self, uint8_t *out,
69                                  size_t out_len);
70 void llvm_blake3_hasher_finalize_seek(const llvm_blake3_hasher *self,
71                                       uint64_t seek, uint8_t *out,
72                                       size_t out_len);
73 void llvm_blake3_hasher_reset(llvm_blake3_hasher *self);
74 
75 #ifdef __cplusplus
76 }
77 #endif
78 
79 #endif /* LLVM_C_BLAKE3_H */
80