xref: /freebsd/crypto/openssh/openbsd-compat/mktemp.c (revision d056fa046c6a91b90cd98165face0e42a33a5173)
1 /* THIS FILE HAS BEEN MODIFIED FROM THE ORIGINAL OPENBSD SOURCE */
2 /* Changes: Removed mktemp */
3 
4 /*	$OpenBSD: mktemp.c,v 1.19 2005/08/08 08:05:36 espie Exp $ */
5 /*
6  * Copyright (c) 1987, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /* OPENBSD ORIGINAL: lib/libc/stdio/mktemp.c */
35 
36 #include "includes.h"
37 
38 #if !defined(HAVE_MKDTEMP) || defined(HAVE_STRICT_MKSTEMP)
39 
40 static int _gettemp(char *, int *, int, int);
41 
42 int
43 mkstemps(char *path, int slen)
44 {
45 	int fd;
46 
47 	return (_gettemp(path, &fd, 0, slen) ? fd : -1);
48 }
49 
50 int
51 mkstemp(char *path)
52 {
53 	int fd;
54 
55 	return (_gettemp(path, &fd, 0, 0) ? fd : -1);
56 }
57 
58 char *
59 mkdtemp(char *path)
60 {
61 	return(_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL);
62 }
63 
64 static int
65 _gettemp(path, doopen, domkdir, slen)
66 	char *path;
67 	register int *doopen;
68 	int domkdir;
69 	int slen;
70 {
71 	register char *start, *trv, *suffp;
72 	struct stat sbuf;
73 	int rval;
74 	pid_t pid;
75 
76 	if (doopen && domkdir) {
77 		errno = EINVAL;
78 		return(0);
79 	}
80 
81 	for (trv = path; *trv; ++trv)
82 		;
83 	trv -= slen;
84 	suffp = trv;
85 	--trv;
86 	if (trv < path) {
87 		errno = EINVAL;
88 		return (0);
89 	}
90 	pid = getpid();
91 	while (trv >= path && *trv == 'X' && pid != 0) {
92 		*trv-- = (pid % 10) + '0';
93 		pid /= 10;
94 	}
95 	while (trv >= path && *trv == 'X') {
96 		char c;
97 
98 		pid = (arc4random() & 0xffff) % (26+26);
99 		if (pid < 26)
100 			c = pid + 'A';
101 		else
102 			c = (pid - 26) + 'a';
103 		*trv-- = c;
104 	}
105 	start = trv + 1;
106 
107 	/*
108 	 * check the target directory; if you have six X's and it
109 	 * doesn't exist this runs for a *very* long time.
110 	 */
111 	if (doopen || domkdir) {
112 		for (;; --trv) {
113 			if (trv <= path)
114 				break;
115 			if (*trv == '/') {
116 				*trv = '\0';
117 				rval = stat(path, &sbuf);
118 				*trv = '/';
119 				if (rval != 0)
120 					return(0);
121 				if (!S_ISDIR(sbuf.st_mode)) {
122 					errno = ENOTDIR;
123 					return(0);
124 				}
125 				break;
126 			}
127 		}
128 	}
129 
130 	for (;;) {
131 		if (doopen) {
132 			if ((*doopen =
133 			    open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
134 				return(1);
135 			if (errno != EEXIST)
136 				return(0);
137 		} else if (domkdir) {
138 			if (mkdir(path, 0700) == 0)
139 				return(1);
140 			if (errno != EEXIST)
141 				return(0);
142 		} else if (lstat(path, &sbuf))
143 			return(errno == ENOENT ? 1 : 0);
144 
145 		/* tricky little algorithm for backward compatibility */
146 		for (trv = start;;) {
147 			if (!*trv)
148 				return (0);
149 			if (*trv == 'Z') {
150 				if (trv == suffp)
151 					return (0);
152 				*trv++ = 'a';
153 			} else {
154 				if (isdigit(*trv))
155 					*trv = 'a';
156 				else if (*trv == 'z')	/* inc from z to A */
157 					*trv = 'A';
158 				else {
159 					if (trv == suffp)
160 						return (0);
161 					++*trv;
162 				}
163 				break;
164 			}
165 		}
166 	}
167 	/*NOTREACHED*/
168 }
169 
170 #endif /* !defined(HAVE_MKDTEMP) || defined(HAVE_STRICT_MKSTEMP) */
171