xref: /freebsd/crypto/openssh/openbsd-compat/mktemp.c (revision d95e11bf7e5a59b5c3f81bd8dfc2918ee7d3bada)
1 /* THIS FILE HAS BEEN MODIFIED FROM THE ORIGINAL OPENBSD SOURCE */
2 /* Changes: Removed mktemp */
3 
4 /*
5  * Copyright (c) 1987, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "includes.h"
34 
35 #if !defined(HAVE_MKDTEMP) || defined(HAVE_STRICT_MKSTEMP)
36 
37 #if defined(LIBC_SCCS) && !defined(lint)
38 static char rcsid[] = "$OpenBSD: mktemp.c,v 1.17 2003/06/02 20:18:37 millert Exp $";
39 #endif /* LIBC_SCCS and not lint */
40 
41 #ifdef HAVE_CYGWIN
42 #define open binary_open
43 extern int binary_open();
44 #endif
45 
46 static int _gettemp(char *, int *, int, int);
47 
48 int
49 mkstemps(path, slen)
50 	char *path;
51 	int slen;
52 {
53 	int fd;
54 
55 	return (_gettemp(path, &fd, 0, slen) ? fd : -1);
56 }
57 
58 int
59 mkstemp(path)
60 	char *path;
61 {
62 	int fd;
63 
64 	return (_gettemp(path, &fd, 0, 0) ? fd : -1);
65 }
66 
67 char *
68 mkdtemp(path)
69 	char *path;
70 {
71 	return(_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL);
72 }
73 
74 static int
75 _gettemp(path, doopen, domkdir, slen)
76 	char *path;
77 	register int *doopen;
78 	int domkdir;
79 	int slen;
80 {
81 	register char *start, *trv, *suffp;
82 	struct stat sbuf;
83 	int rval;
84 	pid_t pid;
85 
86 	if (doopen && domkdir) {
87 		errno = EINVAL;
88 		return(0);
89 	}
90 
91 	for (trv = path; *trv; ++trv)
92 		;
93 	trv -= slen;
94 	suffp = trv;
95 	--trv;
96 	if (trv < path) {
97 		errno = EINVAL;
98 		return (0);
99 	}
100 	pid = getpid();
101 	while (trv >= path && *trv == 'X' && pid != 0) {
102 		*trv-- = (pid % 10) + '0';
103 		pid /= 10;
104 	}
105 	while (trv >= path && *trv == 'X') {
106 		char c;
107 
108 		pid = (arc4random() & 0xffff) % (26+26);
109 		if (pid < 26)
110 			c = pid + 'A';
111 		else
112 			c = (pid - 26) + 'a';
113 		*trv-- = c;
114 	}
115 	start = trv + 1;
116 
117 	/*
118 	 * check the target directory; if you have six X's and it
119 	 * doesn't exist this runs for a *very* long time.
120 	 */
121 	if (doopen || domkdir) {
122 		for (;; --trv) {
123 			if (trv <= path)
124 				break;
125 			if (*trv == '/') {
126 				*trv = '\0';
127 				rval = stat(path, &sbuf);
128 				*trv = '/';
129 				if (rval != 0)
130 					return(0);
131 				if (!S_ISDIR(sbuf.st_mode)) {
132 					errno = ENOTDIR;
133 					return(0);
134 				}
135 				break;
136 			}
137 		}
138 	}
139 
140 	for (;;) {
141 		if (doopen) {
142 			if ((*doopen =
143 			    open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
144 				return(1);
145 			if (errno != EEXIST)
146 				return(0);
147 		} else if (domkdir) {
148 			if (mkdir(path, 0700) == 0)
149 				return(1);
150 			if (errno != EEXIST)
151 				return(0);
152 		} else if (lstat(path, &sbuf))
153 			return(errno == ENOENT ? 1 : 0);
154 
155 		/* tricky little algorithm for backward compatibility */
156 		for (trv = start;;) {
157 			if (!*trv)
158 				return (0);
159 			if (*trv == 'Z') {
160 				if (trv == suffp)
161 					return (0);
162 				*trv++ = 'a';
163 			} else {
164 				if (isdigit(*trv))
165 					*trv = 'a';
166 				else if (*trv == 'z')	/* inc from z to A */
167 					*trv = 'A';
168 				else {
169 					if (trv == suffp)
170 						return (0);
171 					++*trv;
172 				}
173 				break;
174 			}
175 		}
176 	}
177 	/*NOTREACHED*/
178 }
179 
180 #endif /* !defined(HAVE_MKDTEMP) || defined(HAVE_STRICT_MKSTEMP) */
181