openssh-portable/readpass.c

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- deraadt@cvs.openbsd.org 2006/08/03 03:34:42 [OVERVIEW atomicio.c atomicio.h auth-bsdauth.c auth-chall.c auth-krb5.c] [auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c] [auth-rsa.c auth-skey.c auth.c auth.h auth1.c auth2-chall.c auth2-gss.c] [auth2-hostbased.c auth2-kbdint.c auth2-none.c auth2-passwd.c ] [auth2-pubkey.c auth2.c authfd.c authfd.h authfile.c bufaux.c bufbn.c] [buffer.c buffer.h canohost.c channels.c channels.h cipher-3des1.c] [cipher-bf1.c cipher-ctr.c cipher.c cleanup.c clientloop.c compat.c] [compress.c deattack.c dh.c dispatch.c dns.c dns.h fatal.c groupaccess.c] [groupaccess.h gss-genr.c gss-serv-krb5.c gss-serv.c hostfile.c kex.c] [kex.h kexdh.c kexdhc.c kexdhs.c kexgex.c kexgexc.c kexgexs.c key.c] [key.h log.c log.h mac.c match.c md-sha256.c misc.c misc.h moduli.c] [monitor.c monitor_fdpass.c monitor_mm.c monitor_mm.h monitor_wrap.c] [monitor_wrap.h msg.c nchan.c packet.c progressmeter.c readconf.c] [readconf.h readpass.c rsa.c scard.c scard.h scp.c servconf.c servconf.h] [serverloop.c session.c session.h sftp-client.c sftp-common.c] [sftp-common.h sftp-glob.c sftp-server.c sftp.c ssh-add.c ssh-agent.c] [ssh-dss.c ssh-gss.h ssh-keygen.c ssh-keyscan.c ssh-keysign.c ssh-rsa.c] [ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c] [sshd.c sshlogin.c sshlogin.h sshpty.c sshpty.h sshtty.c ttymodes.c] [uidswap.c uidswap.h uuencode.c uuencode.h xmalloc.c xmalloc.h] [loginrec.c loginrec.h openbsd-compat/port-aix.c openbsd-compat/port-tun.h] almost entirely get rid of the culture of ".h files that include .h files" ok djm, sort of ok stevesk makes the pain stop in one easy step NB. portable commit contains everything *except* removing includes.h, as that will take a fair bit more work as we move headers that are required for portability workarounds to defines.h. (also, this step wasn't "easy")
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/* $OpenBSD: readpass.c,v 1.47 2006/08/03 03:34:42 deraadt Exp $ */
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/*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
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#include "includes.h"
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <fcntl.h>
#ifdef HAVE_PATHS_H
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# include <paths.h>
#endif
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
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#include "xmalloc.h"
#include "misc.h"
#include "pathnames.h"
#include "log.h"
#include "ssh.h"
#include "uidswap.h"
static char *
ssh_askpass(char *askpass, const char *msg)
{
pid_t pid;
size_t len;
char *pass;
int p[2], status, ret;
char buf[1024];
if (fflush(stdout) != 0)
error("ssh_askpass: fflush: %s", strerror(errno));
if (askpass == NULL)
fatal("internal error: askpass undefined");
if (pipe(p) < 0) {
error("ssh_askpass: pipe: %s", strerror(errno));
return NULL;
}
if ((pid = fork()) < 0) {
error("ssh_askpass: fork: %s", strerror(errno));
return NULL;
}
if (pid == 0) {
permanently_drop_suid(getuid());
close(p[0]);
if (dup2(p[1], STDOUT_FILENO) < 0)
fatal("ssh_askpass: dup2: %s", strerror(errno));
execlp(askpass, askpass, msg, (char *) 0);
fatal("ssh_askpass: exec(%s): %s", askpass, strerror(errno));
}
close(p[1]);
len = ret = 0;
do {
ret = read(p[0], buf + len, sizeof(buf) - 1 - len);
if (ret == -1 && errno == EINTR)
continue;
if (ret <= 0)
break;
len += ret;
} while (sizeof(buf) - 1 - len > 0);
buf[len] = '\0';
close(p[0]);
while (waitpid(pid, &status, 0) < 0)
if (errno != EINTR)
break;
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
memset(buf, 0, sizeof(buf));
return NULL;
}
buf[strcspn(buf, "\r\n")] = '\0';
pass = xstrdup(buf);
memset(buf, 0, sizeof(buf));
return pass;
}
/*
* Reads a passphrase from /dev/tty with echo turned off/on. Returns the
* passphrase (allocated with xmalloc). Exits if EOF is encountered. If
* RP_ALLOW_STDIN is set, the passphrase will be read from stdin if no
* tty is available
- (djm) Big OpenBSD sync: - markus@cvs.openbsd.org 2000/09/30 10:27:44 [log.c] allow loglevel debug - markus@cvs.openbsd.org 2000/10/03 11:59:57 [packet.c] hmac->mac - markus@cvs.openbsd.org 2000/10/03 12:03:03 [auth-krb4.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c] move fake-auth from auth1.c to individual auth methods, disables s/key in debug-msg - markus@cvs.openbsd.org 2000/10/03 12:16:48 ssh.c do not resolve canonname, i have no idea why this was added oin ossh - markus@cvs.openbsd.org 2000/10/09 15:30:44 ssh-keygen.1 ssh-keygen.c -X now reads private ssh.com DSA keys, too. - markus@cvs.openbsd.org 2000/10/09 15:32:34 auth-options.c clear options on every call. - markus@cvs.openbsd.org 2000/10/09 15:51:00 authfd.c authfd.h interop with ssh-agent2, from <res@shore.net> - markus@cvs.openbsd.org 2000/10/10 14:20:45 compat.c use rexexp for version string matching - provos@cvs.openbsd.org 2000/10/10 22:02:18 [kex.c kex.h myproposal.h ssh.h ssh2.h sshconnect2.c sshd.c dh.c dh.h] First rough implementation of the diffie-hellman group exchange. The client can ask the server for bigger groups to perform the diffie-hellman in, thus increasing the attack complexity when using ciphers with longer keys. University of Windsor provided network, T the company. - markus@cvs.openbsd.org 2000/10/11 13:59:52 [auth-rsa.c auth2.c] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:00:27 [auth-options.h] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:03:27 [scp.1 scp.c] support 'scp -o' with help from mouring@pconline.com - markus@cvs.openbsd.org 2000/10/11 14:11:35 [dh.c] Wall - markus@cvs.openbsd.org 2000/10/11 14:14:40 [auth.h auth2.c readconf.c readconf.h readpass.c servconf.c servconf.h] [ssh.h sshconnect2.c sshd_config auth2-skey.c cli.c cli.h] add support for s/key (kbd-interactive) to ssh2, based on work by mkiernan@avantgo.com and me - markus@cvs.openbsd.org 2000/10/11 14:27:24 [auth.c auth1.c auth2.c authfile.c cipher.c cipher.h kex.c kex.h] [myproposal.h packet.c readconf.c session.c ssh.c ssh.h sshconnect1.c] [sshconnect2.c sshd.c] new cipher framework - markus@cvs.openbsd.org 2000/10/11 14:45:21 [cipher.c] remove DES - markus@cvs.openbsd.org 2000/10/12 03:59:20 [cipher.c cipher.h sshconnect1.c sshconnect2.c sshd.c] enable DES in SSH-1 clients only - markus@cvs.openbsd.org 2000/10/12 08:21:13 [kex.h packet.c] remove unused - markus@cvs.openbsd.org 2000/10/13 12:34:46 [sshd.c] Kludge for F-Secure Macintosh < 1.0.2; appro@fy.chalmers.se - markus@cvs.openbsd.org 2000/10/13 12:59:15 [cipher.c cipher.h myproposal.h rijndael.c rijndael.h] rijndael/aes support - markus@cvs.openbsd.org 2000/10/13 13:10:54 [sshd.8] more info about -V - markus@cvs.openbsd.org 2000/10/13 13:12:02 [myproposal.h] prefer no compression
2000-10-14 07:23:11 +02:00
*/
char *
read_passphrase(const char *prompt, int flags)
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{
char *askpass = NULL, *ret, buf[1024];
int rppflags, use_askpass = 0, ttyfd;
rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
if (flags & RP_USE_ASKPASS)
use_askpass = 1;
else if (flags & RP_ALLOW_STDIN) {
if (!isatty(STDIN_FILENO)) {
debug("read_passphrase: stdin is not a tty");
use_askpass = 1;
}
} else {
rppflags |= RPP_REQUIRE_TTY;
ttyfd = open(_PATH_TTY, O_RDWR);
if (ttyfd >= 0)
close(ttyfd);
else {
debug("read_passphrase: can't open %s: %s", _PATH_TTY,
strerror(errno));
use_askpass = 1;
}
}
if ((flags & RP_USE_ASKPASS) && getenv("DISPLAY") == NULL)
return (flags & RP_ALLOW_EOF) ? NULL : xstrdup("");
if (use_askpass && getenv("DISPLAY")) {
if (getenv(SSH_ASKPASS_ENV))
askpass = getenv(SSH_ASKPASS_ENV);
else
askpass = _PATH_SSH_ASKPASS_DEFAULT;
if ((ret = ssh_askpass(askpass, prompt)) == NULL)
if (!(flags & RP_ALLOW_EOF))
return xstrdup("");
return ret;
}
if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL) {
if (flags & RP_ALLOW_EOF)
return NULL;
return xstrdup("");
}
ret = xstrdup(buf);
memset(buf, 'x', sizeof buf);
return ret;
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}
int
ask_permission(const char *fmt, ...)
{
va_list args;
char *p, prompt[1024];
int allowed = 0;
va_start(args, fmt);
vsnprintf(prompt, sizeof(prompt), fmt, args);
va_end(args);
p = read_passphrase(prompt, RP_USE_ASKPASS|RP_ALLOW_EOF);
if (p != NULL) {
/*
* Accept empty responses and responses consisting
* of the word "yes" as affirmative.
*/
if (*p == '\0' || *p == '\n' ||
strcasecmp(p, "yes") == 0)
allowed = 1;
xfree(p);
}
return (allowed);
}