GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.bin/ssh/lib/../readpass.c Lines: 0 83 0.0 %
Date: 2017-11-13 Branches: 0 68 0.0 %

Line Branch Exec Source
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/* $OpenBSD: readpass.c,v 1.51 2015/12/11 00:20:04 mmcc Exp $ */
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/*
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 * Copyright (c) 2001 Markus Friedl.  All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <paths.h>
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#include <readpassphrase.h>
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#include <signal.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "xmalloc.h"
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#include "misc.h"
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#include "pathnames.h"
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#include "log.h"
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#include "ssh.h"
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#include "uidswap.h"
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static char *
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ssh_askpass(char *askpass, const char *msg)
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{
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	pid_t pid, ret;
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	size_t len;
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	char *pass;
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	int p[2], status;
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	char buf[1024];
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	void (*osigchld)(int);
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	if (fflush(stdout) != 0)
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		error("ssh_askpass: fflush: %s", strerror(errno));
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	if (askpass == NULL)
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		fatal("internal error: askpass undefined");
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	if (pipe(p) < 0) {
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		error("ssh_askpass: pipe: %s", strerror(errno));
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		return NULL;
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	}
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	osigchld = signal(SIGCHLD, SIG_DFL);
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	if ((pid = fork()) < 0) {
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		error("ssh_askpass: fork: %s", strerror(errno));
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		signal(SIGCHLD, osigchld);
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		return NULL;
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	}
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	if (pid == 0) {
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		permanently_drop_suid(getuid());
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		close(p[0]);
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		if (dup2(p[1], STDOUT_FILENO) < 0)
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			fatal("ssh_askpass: dup2: %s", strerror(errno));
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		execlp(askpass, askpass, msg, (char *)NULL);
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		fatal("ssh_askpass: exec(%s): %s", askpass, strerror(errno));
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	}
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	close(p[1]);
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	len = 0;
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	do {
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		ssize_t r = read(p[0], buf + len, sizeof(buf) - 1 - len);
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		if (r == -1 && errno == EINTR)
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			continue;
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		if (r <= 0)
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			break;
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		len += r;
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	} while (sizeof(buf) - 1 - len > 0);
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	buf[len] = '\0';
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	close(p[0]);
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	while ((ret = waitpid(pid, &status, 0)) < 0)
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		if (errno != EINTR)
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			break;
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	signal(SIGCHLD, osigchld);
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	if (ret == -1 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
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		explicit_bzero(buf, sizeof(buf));
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		return NULL;
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	}
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	buf[strcspn(buf, "\r\n")] = '\0';
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	pass = xstrdup(buf);
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	explicit_bzero(buf, sizeof(buf));
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	return pass;
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}
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/*
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 * Reads a passphrase from /dev/tty with echo turned off/on.  Returns the
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 * passphrase (allocated with xmalloc).  Exits if EOF is encountered. If
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 * RP_ALLOW_STDIN is set, the passphrase will be read from stdin if no
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 * tty is available
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 */
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char *
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read_passphrase(const char *prompt, int flags)
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{
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	char *askpass = NULL, *ret, buf[1024];
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	int rppflags, use_askpass = 0, ttyfd;
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	rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
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	if (flags & RP_USE_ASKPASS)
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		use_askpass = 1;
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	else if (flags & RP_ALLOW_STDIN) {
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		if (!isatty(STDIN_FILENO)) {
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			debug("read_passphrase: stdin is not a tty");
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			use_askpass = 1;
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		}
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	} else {
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		rppflags |= RPP_REQUIRE_TTY;
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		ttyfd = open(_PATH_TTY, O_RDWR);
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		if (ttyfd >= 0)
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			close(ttyfd);
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		else {
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			debug("read_passphrase: can't open %s: %s", _PATH_TTY,
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			    strerror(errno));
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			use_askpass = 1;
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		}
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	}
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	if ((flags & RP_USE_ASKPASS) && getenv("DISPLAY") == NULL)
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		return (flags & RP_ALLOW_EOF) ? NULL : xstrdup("");
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	if (use_askpass && getenv("DISPLAY")) {
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		if (getenv(SSH_ASKPASS_ENV))
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			askpass = getenv(SSH_ASKPASS_ENV);
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		else
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			askpass = _PATH_SSH_ASKPASS_DEFAULT;
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		if ((ret = ssh_askpass(askpass, prompt)) == NULL)
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			if (!(flags & RP_ALLOW_EOF))
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				return xstrdup("");
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		return ret;
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	}
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	if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL) {
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		if (flags & RP_ALLOW_EOF)
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			return NULL;
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		return xstrdup("");
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	}
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	ret = xstrdup(buf);
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	explicit_bzero(buf, sizeof(buf));
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	return ret;
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}
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int
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ask_permission(const char *fmt, ...)
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{
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	va_list args;
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	char *p, prompt[1024];
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	int allowed = 0;
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	va_start(args, fmt);
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	vsnprintf(prompt, sizeof(prompt), fmt, args);
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	va_end(args);
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	p = read_passphrase(prompt, RP_USE_ASKPASS|RP_ALLOW_EOF);
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	if (p != NULL) {
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		/*
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		 * Accept empty responses and responses consisting
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		 * of the word "yes" as affirmative.
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		 */
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		if (*p == '\0' || *p == '\n' ||
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		    strcasecmp(p, "yes") == 0)
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			allowed = 1;
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		free(p);
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	}
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	return (allowed);
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}