1 /* $OpenBSD: helper.c,v 1.18 2019/06/28 13:32:41 deraadt Exp $ */
2
3 /*
4 * Copyright (c) 2000 Poul-Henning Kamp <phk@FreeBSD.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 /*
20 * If we meet some day, and you think this stuff is worth it, you
21 * can buy me a beer in return. Poul-Henning Kamp
22 */
23
24 #include <sys/types.h>
25 #include <sys/stat.h>
26
27 #include <errno.h>
28 #include <fcntl.h>
29 #include <stdlib.h>
30 #include <stdio.h>
31 #include <string.h>
32 #include <unistd.h>
33
34 #include <hashinc>
35
36 #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
37
38 char *
HASHEnd(HASH_CTX * ctx,char * buf)39 HASHEnd(HASH_CTX *ctx, char *buf)
40 {
41 int i;
42 u_int8_t digest[HASH_DIGEST_LENGTH];
43 static const char hex[] = "0123456789abcdef";
44
45 if (buf == NULL && (buf = malloc(HASH_DIGEST_STRING_LENGTH)) == NULL)
46 return (NULL);
47
48 HASHFinal(digest, ctx);
49 for (i = 0; i < HASH_DIGEST_LENGTH; i++) {
50 buf[i + i] = hex[digest[i] >> 4];
51 buf[i + i + 1] = hex[digest[i] & 0x0f];
52 }
53 buf[i + i] = '\0';
54 explicit_bzero(digest, sizeof(digest));
55 return (buf);
56 }
57 DEF_WEAK(HASHEnd);
58
59 char *
HASHFileChunk(const char * filename,char * buf,off_t off,off_t len)60 HASHFileChunk(const char *filename, char *buf, off_t off, off_t len)
61 {
62 struct stat sb;
63 u_char buffer[BUFSIZ];
64 HASH_CTX ctx;
65 int fd, save_errno;
66 ssize_t nr;
67
68 HASHInit(&ctx);
69
70 if ((fd = open(filename, O_RDONLY)) == -1)
71 return (NULL);
72 if (len == 0) {
73 if (fstat(fd, &sb) == -1) {
74 save_errno = errno;
75 close(fd);
76 errno = save_errno;
77 return (NULL);
78 }
79 len = sb.st_size;
80 }
81 if (off > 0 && lseek(fd, off, SEEK_SET) == -1) {
82 save_errno = errno;
83 close(fd);
84 errno = save_errno;
85 return (NULL);
86 }
87
88 while ((nr = read(fd, buffer, MINIMUM(sizeof(buffer), len))) > 0) {
89 HASHUpdate(&ctx, buffer, nr);
90 if (len > 0 && (len -= nr) == 0)
91 break;
92 }
93
94 save_errno = errno;
95 close(fd);
96 errno = save_errno;
97 return (nr == -1 ? NULL : HASHEnd(&ctx, buf));
98 }
99 DEF_WEAK(HASHFileChunk);
100
101 char *
HASHFile(const char * filename,char * buf)102 HASHFile(const char *filename, char *buf)
103 {
104 return (HASHFileChunk(filename, buf, 0, 0));
105 }
106 DEF_WEAK(HASHFile);
107
108 char *
HASHData(const u_char * data,size_t len,char * buf)109 HASHData(const u_char *data, size_t len, char *buf)
110 {
111 HASH_CTX ctx;
112
113 HASHInit(&ctx);
114 HASHUpdate(&ctx, data, len);
115 return (HASHEnd(&ctx, buf));
116 }
117 DEF_WEAK(HASHData);
118