1 /* Declarations of functions and data types used for SHA256 and SHA224 sum
2 library functions.
3 Copyright (C) 2005-2006, 2008-2023 Free Software Foundation, Inc.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 #ifndef SHA256_H
19 # define SHA256_H 1
20
21 /* This file uses HAVE_OPENSSL_SHA256. */
22 # if !_GL_CONFIG_H_INCLUDED
23 # error "Please include config.h first."
24 # endif
25
26 # include <stdio.h>
27 # include <stdint.h>
28
29 # if HAVE_OPENSSL_SHA256
30 # ifndef OPENSSL_API_COMPAT
31 # define OPENSSL_API_COMPAT 0x10101000L /* FIXME: Use OpenSSL 1.1+ API. */
32 # endif
33 # include <openssl/sha.h>
34 # endif
35
36 # ifdef __cplusplus
37 extern "C" {
38 # endif
39
40 enum { SHA224_DIGEST_SIZE = 224 / 8 };
41 enum { SHA256_DIGEST_SIZE = 256 / 8 };
42
43 # if HAVE_OPENSSL_SHA256
44 # define GL_OPENSSL_NAME 224
45 # include "gl_openssl.h"
46 # define GL_OPENSSL_NAME 256
47 # include "gl_openssl.h"
48 # else
49 /* Structure to save state of computation between the single steps. */
50 struct sha256_ctx
51 {
52 uint32_t state[8];
53
54 uint32_t total[2];
55 size_t buflen; /* ≥ 0, ≤ 128 */
56 uint32_t buffer[32]; /* 128 bytes; the first buflen bytes are in use */
57 };
58
59 /* Initialize structure containing state of computation. */
60 extern void sha256_init_ctx (struct sha256_ctx *ctx);
61 extern void sha224_init_ctx (struct sha256_ctx *ctx);
62
63 /* Starting with the result of former calls of this function (or the
64 initialization function update the context for the next LEN bytes
65 starting at BUFFER.
66 It is necessary that LEN is a multiple of 64!!! */
67 extern void sha256_process_block (const void *buffer, size_t len,
68 struct sha256_ctx *ctx);
69
70 /* Starting with the result of former calls of this function (or the
71 initialization function update the context for the next LEN bytes
72 starting at BUFFER.
73 It is NOT required that LEN is a multiple of 64. */
74 extern void sha256_process_bytes (const void *buffer, size_t len,
75 struct sha256_ctx *ctx);
76
77 /* Process the remaining bytes in the buffer and put result from CTX
78 in first 32 (28) bytes following RESBUF. The result is always in little
79 endian byte order, so that a byte-wise output yields to the wanted
80 ASCII representation of the message digest. */
81 extern void *sha256_finish_ctx (struct sha256_ctx *ctx, void *restrict resbuf);
82 extern void *sha224_finish_ctx (struct sha256_ctx *ctx, void *restrict resbuf);
83
84
85 /* Put result from CTX in first 32 (28) bytes following RESBUF. The result is
86 always in little endian byte order, so that a byte-wise output yields
87 to the wanted ASCII representation of the message digest. */
88 extern void *sha256_read_ctx (const struct sha256_ctx *ctx,
89 void *restrict resbuf);
90 extern void *sha224_read_ctx (const struct sha256_ctx *ctx,
91 void *restrict resbuf);
92
93
94 /* Compute SHA256 (SHA224) message digest for LEN bytes beginning at BUFFER.
95 The result is always in little endian byte order, so that a byte-wise
96 output yields to the wanted ASCII representation of the message
97 digest. */
98 extern void *sha256_buffer (const char *buffer, size_t len,
99 void *restrict resblock);
100 extern void *sha224_buffer (const char *buffer, size_t len,
101 void *restrict resblock);
102
103 # endif
104
105 /* Compute SHA256 (SHA224) message digest for bytes read from STREAM.
106 STREAM is an open file stream. Regular files are handled more efficiently.
107 The contents of STREAM from its current position to its end will be read.
108 The case that the last operation on STREAM was an 'ungetc' is not supported.
109 The resulting message digest number will be written into the 32 (28) bytes
110 beginning at RESBLOCK. */
111 extern int sha256_stream (FILE *stream, void *resblock);
112 extern int sha224_stream (FILE *stream, void *resblock);
113
114
115 # ifdef __cplusplus
116 }
117 # endif
118
119 #endif
120
121 /*
122 * Hey Emacs!
123 * Local Variables:
124 * coding: utf-8
125 * End:
126 */