1 /* THIS FILE HAS BEEN MODIFIED FROM THE ORIGINAL OPENBSD SOURCE */
2 /* Changes: Removed mktemp */
3 
4 /*	$OpenBSD: mktemp.c,v 1.30 2010/03/21 23:09:30 schwarze Exp $ */
5 /*
6  * Copyright (c) 1996-1998, 2008 Theo de Raadt
7  * Copyright (c) 1997, 2008-2009 Todd C. Miller
8  *
9  * Permission to use, copy, modify, and distribute this software for any
10  * purpose with or without fee is hereby granted, provided that the above
11  * copyright notice and this permission notice appear in all copies.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
14  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
16  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
19  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20  */
21 
22 /* OPENBSD ORIGINAL: lib/libc/stdio/mktemp.c */
23 
24 #include "includes.h"
25 
26 #include <sys/types.h>
27 #include <sys/stat.h>
28 #include <errno.h>
29 #include <fcntl.h>
30 #include <limits.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <ctype.h>
35 #include <unistd.h>
36 
37 #if !defined(HAVE_MKDTEMP)
38 
39 #define MKTEMP_NAME	0
40 #define MKTEMP_FILE	1
41 #define MKTEMP_DIR	2
42 
43 #define TEMPCHARS	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
44 #define NUM_CHARS	(sizeof(TEMPCHARS) - 1)
45 
46 static int
mktemp_internal(char * path,int slen,int mode)47 mktemp_internal(char *path, int slen, int mode)
48 {
49 	char *start, *cp, *ep;
50 	const char *tempchars = TEMPCHARS;
51 	unsigned int r, tries;
52 	struct stat sb;
53 	size_t len;
54 	int fd;
55 
56 	len = strlen(path);
57 	if (len == 0 || slen < 0 || (size_t)slen >= len) {
58 		errno = EINVAL;
59 		return(-1);
60 	}
61 	ep = path + len - slen;
62 
63 	tries = 1;
64 	for (start = ep; start > path && start[-1] == 'X'; start--) {
65 		if (tries < INT_MAX / NUM_CHARS)
66 			tries *= NUM_CHARS;
67 	}
68 	tries *= 2;
69 
70 	do {
71 		for (cp = start; cp != ep; cp++) {
72 			r = arc4random_uniform(NUM_CHARS);
73 			*cp = tempchars[r];
74 		}
75 
76 		switch (mode) {
77 		case MKTEMP_NAME:
78 			if (lstat(path, &sb) != 0)
79 				return(errno == ENOENT ? 0 : -1);
80 			break;
81 		case MKTEMP_FILE:
82 			fd = open(path, O_CREAT|O_EXCL|O_RDWR, S_IRUSR|S_IWUSR);
83 			if (fd != -1 || errno != EEXIST)
84 				return(fd);
85 			break;
86 		case MKTEMP_DIR:
87 			if (mkdir(path, S_IRUSR|S_IWUSR|S_IXUSR) == 0)
88 				return(0);
89 			if (errno != EEXIST)
90 				return(-1);
91 			break;
92 		}
93 	} while (--tries);
94 
95 	errno = EEXIST;
96 	return(-1);
97 }
98 
99 #if 0
100 char *_mktemp(char *);
101 
102 char *
103 _mktemp(char *path)
104 {
105 	if (mktemp_internal(path, 0, MKTEMP_NAME) == -1)
106 		return(NULL);
107 	return(path);
108 }
109 
110 __warn_references(mktemp,
111     "warning: mktemp() possibly used unsafely; consider using mkstemp()");
112 
113 char *
114 mktemp(char *path)
115 {
116 	return(_mktemp(path));
117 }
118 #endif
119 
120 int
mkstemp(char * path)121 mkstemp(char *path)
122 {
123 	return(mktemp_internal(path, 0, MKTEMP_FILE));
124 }
125 
126 int
mkstemps(char * path,int slen)127 mkstemps(char *path, int slen)
128 {
129 	return(mktemp_internal(path, slen, MKTEMP_FILE));
130 }
131 
132 char *
mkdtemp(char * path)133 mkdtemp(char *path)
134 {
135 	int error;
136 
137 	error = mktemp_internal(path, 0, MKTEMP_DIR);
138 	return(error ? NULL : path);
139 }
140 
141 #endif /* !defined(HAVE_MKDTEMP) */
142