/*
* Connect to the given ssh server using a proxy command.
*/
static int
ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
{
/*
* Win32 code.
*/
#ifdef WIN32_FIXME
PROCESS_INFORMATION pi = {0};
STARTUPINFO si = {0};
char *fullCmd = NULL;
char strport[NI_MAXSERV] = {0};
int sockin[2] = {-1, -1};
int sockout[2] = {-1, -1};
int exitCode = -1;
/*
* Create command to execute as proxy.
*/
debug("Creating proxy command...");
snprintf(strport, sizeof strport, "%hu", port);
fullCmd = percent_expand(proxy_command, "h", host,
"p", strport, (char *) NULL);
FAIL(fullCmd == NULL);
/*
* Create socket pairs for stdin and stdout.
*/
debug("Creating socket pairs for proxy process...");
socketpair(sockin);
socketpair(sockout);
debug("sockin[0]: %d sockin[1]: %d", sockin[0], sockin[1]);
debug("sockout[0]: %d sockout[1]: %d", sockout[0], sockout[1]);
permanently_drop_suid(original_real_uid);
/*
* Assign sockets to StartupInfo
*/
si.cb = sizeof(STARTUPINFO);
si.hStdInput = (HANDLE) sfd_to_handle(sockin[0]);
si.hStdOutput = (HANDLE) sfd_to_handle(sockout[0]);
si.hStdError = GetStdHandle(STD_ERROR_HANDLE);
si.wShowWindow = SW_HIDE;
si.dwFlags = STARTF_USESTDHANDLES;
si.lpDesktop = NULL;
/*
* Create proxy process with given stdout/stdin.
*/
debug("Executing proxy command: \"%.500s\"...\n", fullCmd);
FAIL(CreateProcess(NULL, fullCmd, NULL, NULL, TRUE,
CREATE_NEW_PROCESS_GROUP, NULL,
NULL, &si, &pi) == FALSE);
proxy_command_handle = pi.hProcess;
proxy_command_pid = pi.dwProcessId;
/*
* Redirect network in/out to proxy sockets.
*/
packet_set_connection(sockout[1], sockin[1]);
exitCode = 0;
fail:
/*
/ Clean up.
*/
close(sockout[0]);
close(sockin[0]);
CloseHandle(pi.hThread);
free(fullCmd);
/*
* Error handler.
*/
if (exitCode)
{
debug("Error cannot create proxy process (%u).\n", (unsigned int) GetLastError());
close(sockout[1]);
close(sockin[1]);
CloseHandle(pi.hProcess);
}
return exitCode;
#else
/*
* Original OpenSSH code.
*/
char *command_string;
int pin[2], pout[2];
pid_t pid;
char *shell;
if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
shell = _PATH_BSHELL;
/* Create pipes for communicating with the proxy. */
if (pipe(pin) < 0 || pipe(pout) < 0)
fatal("Could not create pipes to communicate with the proxy: %.100s",
strerror(errno));
command_string = expand_proxy_command(proxy_command, options.user,
host, port);
debug("Executing proxy command: %.500s", command_string);
/* Fork and execute the proxy command. */
if ((pid = fork()) == 0) {
char *argv[10];
/* Child. Permanently give up superuser privileges. */
permanently_drop_suid(original_real_uid);
/* Redirect stdin and stdout. */
close(pin[1]);
if (pin[0] != 0) {
if (dup2(pin[0], 0) < 0)
perror("dup2 stdin");
close(pin[0]);
}
close(pout[0]);
if (dup2(pout[1], 1) < 0)
perror("dup2 stdout");
/* Cannot be 1 because pin allocated two descriptors. */
close(pout[1]);
/* Stderr is left as it is so that error messages get
printed on the user's terminal. */
argv[0] = shell;
argv[1] = "-c";
argv[2] = command_string;
argv[3] = NULL;
/* Execute the proxy command. Note that we gave up any
extra privileges above. */
signal(SIGPIPE, SIG_DFL);
execv(argv[0], argv);
perror(argv[0]);
exit(1);
}
/* Parent. */
if (pid < 0)
fatal("fork failed: %.100s", strerror(errno));
else
proxy_command_pid = pid; /* save pid to clean up later */
/* Close child side of the descriptors. */
close(pin[0]);
close(pout[1]);
/* Free the command name. */
free(command_string);
/* Set the connection file descriptors. */
packet_set_connection(pout[0], pin[1]);
/* Indicate OK return */
return 0;
#endif /* else WIN32_FIXME */
}
/*
* Connect to the given ssh server using a proxy command that passes a
* a connected fd back to us.
*/
static int
ssh_proxy_fdpass_connect(const char *host, u_short port,
const char *proxy_command)
{
#ifdef WIN32_FIXME
//PRAGMA:TODO
return 0;
#else
char *command_string;
int sp[2], sock;
pid_t pid;
char *shell;
if ((shell = getenv("SHELL")) == NULL)
shell = _PATH_BSHELL;
if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) < 0)
fatal("Could not create socketpair to communicate with "
"proxy dialer: %.100s", strerror(errno));
command_string = expand_proxy_command(proxy_command, options.user,
host, port);
debug("Executing proxy dialer command: %.500s", command_string);
/* Fork and execute the proxy command. */
if ((pid = fork()) == 0) {
char *argv[10];
/* Child. Permanently give up superuser privileges. */
permanently_drop_suid(original_real_uid);
close(sp[1]);
/* Redirect stdin and stdout. */
if (sp[0] != 0) {
if (dup2(sp[0], 0) < 0)
perror("dup2 stdin");
}
if (sp[0] != 1) {
if (dup2(sp[0], 1) < 0)
perror("dup2 stdout");
}
if (sp[0] >= 2)
close(sp[0]);
/*
* Stderr is left as it is so that error messages get
* printed on the user's terminal.
*/
argv[0] = shell;
argv[1] = "-c";
argv[2] = command_string;
argv[3] = NULL;
/*
* Execute the proxy command.
* Note that we gave up any extra privileges above.
*/
execv(argv[0], argv);
perror(argv[0]);
exit(1);
}
/* Parent. */
if (pid < 0)
fatal("fork failed: %.100s", strerror(errno));
close(sp[0]);
free(command_string);
if ((sock = mm_receive_fd(sp[1])) == -1)
fatal("proxy dialer did not pass back a connection");
while (waitpid(pid, NULL, 0) == -1)
if (errno != EINTR)
fatal("Couldn't wait for child: %s", strerror(errno));
/* Set the connection file descriptors. */
packet_set_connection(sock, sock);
return 0;
#endif
}
/*
* Connect to the given ssh server using a proxy command.
*/
static struct ssh *
ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
{
struct ssh *ssh;
char *command_string, *tmp;
int pin[2], pout[2];
pid_t pid;
char *shell, strport[NI_MAXSERV];
if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
shell = _PATH_BSHELL;
/* Convert the port number into a string. */
snprintf(strport, sizeof strport, "%hu", port);
/*
* Build the final command string in the buffer by making the
* appropriate substitutions to the given proxy command.
*
* Use "exec" to avoid "sh -c" processes on some platforms
* (e.g. Solaris)
*/
xasprintf(&tmp, "exec %s", proxy_command);
command_string = percent_expand(tmp, "h", host, "p", strport,
"r", options.user, (char *)NULL);
xfree(tmp);
/* Create pipes for communicating with the proxy. */
if (pipe(pin) < 0 || pipe(pout) < 0)
fatal("Could not create pipes to communicate with the proxy: %.100s",
strerror(errno));
debug("Executing proxy command: %.500s", command_string);
/* Fork and execute the proxy command. */
if ((pid = fork()) == 0) {
char *argv[10];
/* Child. Permanently give up superuser privileges. */
permanently_drop_suid(original_real_uid);
/* Redirect stdin and stdout. */
close(pin[1]);
if (pin[0] != 0) {
if (dup2(pin[0], 0) < 0)
perror("dup2 stdin");
close(pin[0]);
}
close(pout[0]);
if (dup2(pout[1], 1) < 0)
perror("dup2 stdout");
/* Cannot be 1 because pin allocated two descriptors. */
close(pout[1]);
/* Stderr is left as it is so that error messages get
printed on the user's terminal. */
argv[0] = shell;
argv[1] = "-c";
argv[2] = command_string;
argv[3] = NULL;
/* Execute the proxy command. Note that we gave up any
extra privileges above. */
signal(SIGPIPE, SIG_DFL);
execv(argv[0], argv);
perror(argv[0]);
exit(1);
}
/* Parent. */
if (pid < 0)
fatal("fork failed: %.100s", strerror(errno));
else
proxy_command_pid = pid; /* save pid to clean up later */
/* Close child side of the descriptors. */
close(pin[0]);
close(pout[1]);
/* Free the command name. */
xfree(command_string);
/* Set the connection file descriptors. */
ssh = ssh_packet_set_connection(NULL, pout[0], pin[1]);
ssh_packet_set_timeout(ssh, options.server_alive_interval,
options.server_alive_count_max);
/* Indicate OK return */
return (ssh);
}
/*
* Connect to the given ssh server using a proxy command.
*/
static int
ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
{
char *command_string;
int pin[2], pout[2];
pid_t pid;
char *shell;
if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
shell = _PATH_BSHELL;
/* Create pipes for communicating with the proxy. */
if (pipe(pin) < 0 || pipe(pout) < 0)
fatal("Could not create pipes to communicate with the proxy: %.100s",
strerror(errno));
command_string = expand_proxy_command(proxy_command, options.user,
host, port);
debug("Executing proxy command: %.500s", command_string);
/* Fork and execute the proxy command. */
if ((pid = fork()) == 0) {
char *argv[10];
/* Child. Permanently give up superuser privileges. */
permanently_drop_suid(original_real_uid);
/* Redirect stdin and stdout. */
close(pin[1]);
if (pin[0] != 0) {
if (dup2(pin[0], 0) < 0)
perror("dup2 stdin");
close(pin[0]);
}
close(pout[0]);
if (dup2(pout[1], 1) < 0)
perror("dup2 stdout");
/* Cannot be 1 because pin allocated two descriptors. */
close(pout[1]);
/* Stderr is left as it is so that error messages get
printed on the user's terminal. */
argv[0] = shell;
argv[1] = "-c";
argv[2] = command_string;
argv[3] = NULL;
/* Execute the proxy command. Note that we gave up any
extra privileges above. */
signal(SIGPIPE, SIG_DFL);
execv(argv[0], argv);
perror(argv[0]);
exit(1);
}
/* Parent. */
if (pid < 0)
fatal("fork failed: %.100s", strerror(errno));
else
proxy_command_pid = pid; /* save pid to clean up later */
/* Close child side of the descriptors. */
close(pin[0]);
close(pout[1]);
/* Free the command name. */
free(command_string);
/* Set the connection file descriptors. */
packet_set_connection(pout[0], pin[1]);
/* Indicate OK return */
return 0;
}
static char *
ssh_askpass(char *askpass, const char *msg)
{
pid_t pid, ret;
size_t len;
char *pass;
int p[2], status;
char buf[1024];
void (*osigchld)(int);
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;
}
osigchld = signal(SIGCHLD, SIG_DFL);
if ((pid = fork()) < 0) {
error("ssh_askpass: fork: %s", strerror(errno));
signal(SIGCHLD, osigchld);
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 = 0;
do {
ssize_t r = read(p[0], buf + len, sizeof(buf) - 1 - len);
if (r == -1 && errno == EINTR)
continue;
if (r <= 0)
break;
len += r;
} while (sizeof(buf) - 1 - len > 0);
buf[len] = '\0';
close(p[0]);
while ((ret = waitpid(pid, &status, 0)) < 0)
if (errno != EINTR)
break;
signal(SIGCHLD, osigchld);
if (ret == -1 || !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;
}
