Annotation of src/usr.bin/ssh/readpass.c, Revision 1.21
1.1 deraadt 1: /*
1.8 deraadt 2: * Copyright (c) 1988, 1993
3: * The Regents of the University of California. All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: * 3. All advertising materials mentioning features or use of this software
14: * must display the following acknowledgement:
15: * This product includes software developed by the University of
16: * California, Berkeley and its contributors.
17: * 4. 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.
1.6 deraadt 32: */
1.1 deraadt 33:
34: #include "includes.h"
1.21 ! markus 35: RCSID("$OpenBSD: readpass.c,v 1.20 2001/07/02 22:29:20 markus Exp $");
1.19 markus 36:
37: #include <readpassphrase.h>
1.1 deraadt 38:
39: #include "xmalloc.h"
1.14 itojun 40: #include "readpass.h"
1.15 markus 41: #include "pathnames.h"
42: #include "log.h"
43: #include "atomicio.h"
44: #include "ssh.h"
45:
1.18 itojun 46: static char *
1.16 mouring 47: ssh_askpass(char *askpass, const char *msg)
1.15 markus 48: {
49: pid_t pid;
50: size_t len;
51: char *nl, *pass;
52: int p[2], status;
53: char buf[1024];
54:
55: if (fflush(stdout) != 0)
56: error("ssh_askpass: fflush: %s", strerror(errno));
57: if (askpass == NULL)
58: fatal("internal error: askpass undefined");
1.21 ! markus 59: if (pipe(p) < 0) {
! 60: error("ssh_askpass: pipe: %s", strerror(errno));
! 61: return xstrdup("");
! 62: }
! 63: if ((pid = fork()) < 0) {
! 64: error("ssh_askpass: fork: %s", strerror(errno));
! 65: return xstrdup("");
! 66: }
1.15 markus 67: if (pid == 0) {
68: seteuid(getuid());
69: setuid(getuid());
70: close(p[0]);
71: if (dup2(p[1], STDOUT_FILENO) < 0)
72: fatal("ssh_askpass: dup2: %s", strerror(errno));
73: execlp(askpass, askpass, msg, (char *) 0);
74: fatal("ssh_askpass: exec(%s): %s", askpass, strerror(errno));
75: }
76: close(p[1]);
77: len = read(p[0], buf, sizeof buf);
78: close(p[0]);
79: while (waitpid(pid, &status, 0) < 0)
80: if (errno != EINTR)
81: break;
82: if (len <= 1)
83: return xstrdup("");
84: nl = strchr(buf, '\n');
85: if (nl)
86: *nl = '\0';
87: pass = xstrdup(buf);
88: memset(buf, 0, sizeof(buf));
89: return pass;
90: }
91:
1.7 markus 92: /*
1.19 markus 93: * Reads a passphrase from /dev/tty with echo turned off/on. Returns the
94: * passphrase (allocated with xmalloc). Exits if EOF is encountered. If
95: * RP_ALLOW_STDIN is set, the passphrase will be read from stdin if no
96: * tty is available
1.12 markus 97: */
1.5 markus 98: char *
1.19 markus 99: read_passphrase(const char *prompt, int flags)
1.1 deraadt 100: {
1.19 markus 101: char *askpass = NULL, *ret, buf[1024];
102: int rppflags, use_askpass = 0, ttyfd;
1.15 markus 103:
1.19 markus 104: rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
105: if (flags & RP_ALLOW_STDIN) {
1.15 markus 106: if (!isatty(STDIN_FILENO))
107: use_askpass = 1;
108: } else {
1.19 markus 109: rppflags |= RPP_REQUIRE_TTY;
1.15 markus 110: ttyfd = open("/dev/tty", O_RDWR);
111: if (ttyfd >= 0)
112: close(ttyfd);
113: else
114: use_askpass = 1;
115: }
116:
117: if (use_askpass && getenv("DISPLAY")) {
118: if (getenv(SSH_ASKPASS_ENV))
119: askpass = getenv(SSH_ASKPASS_ENV);
120: else
121: askpass = _PATH_SSH_ASKPASS_DEFAULT;
122: return ssh_askpass(askpass, prompt);
123: }
124:
1.19 markus 125: if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL)
1.20 markus 126: return xstrdup("");
1.19 markus 127:
128: ret = xstrdup(buf);
129: memset(buf, 'x', sizeof buf);
130: return ret;
1.1 deraadt 131: }