xref: /dragonfly/libexec/ftpd/site_md5.c (revision bf2127be)
1 /*
2  * Copyright (c) 2019 The DragonFly Project.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
14  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
15  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
16  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
17  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
19  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
21  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
23  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/types.h>
28 #include <sys/stat.h>
29 #include <errno.h>
30 #include <fcntl.h>
31 #include <unistd.h>
32 #include <openssl/md5.h>
33 
34 #include <stdio.h>		/* for FILE in extern.h */
35 #include <netinet/in.h>		/* for struct sockaddr_in */
36 #include "extern.h"
37 
38 char *
sitemd5(const char * filename,char * const buf)39 sitemd5(const char *filename, char * const buf)
40 {
41 	unsigned char digest[MD5_DIGEST_LENGTH];
42 	static const char hex[]="0123456789abcdef";
43 	MD5_CTX ctx;
44 	unsigned char buffer[4096];
45 	struct stat st;
46 	off_t size;
47 	int fd, bytes, i, saved_errno;
48 
49 	if (!buf)
50 		return NULL;
51 
52 	fd = open(filename, O_RDONLY);
53 	if (fd < 0)
54 		return NULL;
55 	if (fstat(fd, &st) < 0) {
56 		bytes = -1;
57 		goto err;
58 	}
59 
60 	MD5_Init(&ctx);
61 	size = st.st_size;
62 	bytes = 0;
63 	while (size > 0) {
64 		if ((size_t)size > sizeof(buffer))
65 			bytes = read(fd, buffer, sizeof(buffer));
66 		else
67 			bytes = read(fd, buffer, size);
68 		if (bytes < 0)
69 			break;
70 		MD5_Update(&ctx, buffer, bytes);
71 		size -= bytes;
72 	}
73 
74 err:
75 	saved_errno = errno;
76 	close(fd);
77 	errno = saved_errno;
78 
79 	if (bytes < 0)
80 		return NULL;
81 
82 	MD5_Final(digest, &ctx);
83 	for (i = 0; i < MD5_DIGEST_LENGTH; i++) {
84 		buf[2*i] = hex[digest[i] >> 4];
85 		buf[2*i+1] = hex[digest[i] & 0x0f];
86 	}
87 	buf[MD5_DIGEST_LENGTH * 2] = '\0';
88 
89 	return buf;
90 }
91