X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/1843a4251fa30af433f6edb8b5e0892d34dbd000..HEAD:/readpass.c diff --git a/readpass.c b/readpass.c index 3b6ed72b..bd144c2e 100644 --- a/readpass.c +++ b/readpass.c @@ -1,6 +1,6 @@ +/* $OpenBSD: readpass.c,v 1.47 2006/08/03 03:34:42 deraadt Exp $ */ /* - * Copyright (c) 1988, 1993 - * The Regents of the University of California. All rights reserved. + * 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 @@ -10,59 +10,65 @@ * 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. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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. + * 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. */ #include "includes.h" -RCSID("$OpenBSD: readpass.c,v 1.19 2001/06/24 05:35:33 markus Exp $"); -#include +#include +#include + +#include +#include +#ifdef HAVE_PATHS_H +# include +#endif +#include +#include +#include +#include +#include #include "xmalloc.h" -#include "readpass.h" +#include "misc.h" #include "pathnames.h" #include "log.h" -#include "atomicio.h" #include "ssh.h" +#include "uidswap.h" static char * ssh_askpass(char *askpass, const char *msg) { pid_t pid; size_t len; - char *nl, *pass; - int p[2], status; + 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) - fatal("ssh_askpass: pipe: %s", strerror(errno)); - if ((pid = fork()) < 0) - fatal("ssh_askpass: fork: %s", strerror(errno)); + 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) { - seteuid(getuid()); - setuid(getuid()); + permanently_drop_suid(getuid()); close(p[0]); if (dup2(p[1], STDOUT_FILENO) < 0) fatal("ssh_askpass: dup2: %s", strerror(errno)); @@ -70,16 +76,29 @@ ssh_askpass(char *askpass, const char *msg) fatal("ssh_askpass: exec(%s): %s", askpass, strerror(errno)); } close(p[1]); - len = read(p[0], buf, sizeof buf); + + 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 (len <= 1) - return xstrdup(""); - nl = strchr(buf, '\n'); - if (nl) - *nl = '\0'; + + 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; @@ -98,30 +117,72 @@ read_passphrase(const char *prompt, int flags) int rppflags, use_askpass = 0, ttyfd; rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF; - if (flags & RP_ALLOW_STDIN) { - if (!isatty(STDIN_FILENO)) + 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("/dev/tty", O_RDWR); + ttyfd = open(_PATH_TTY, O_RDWR); if (ttyfd >= 0) close(ttyfd); - else + 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; - return ssh_askpass(askpass, prompt); + if ((ret = ssh_askpass(askpass, prompt)) == NULL) + if (!(flags & RP_ALLOW_EOF)) + return xstrdup(""); + return ret; } - if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL) - return NULL; + 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; } + +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); +}