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4da1f2b17e
putty-source/windows/winplink.c
Jacob Nevins 8719f92c14 Revamp SSH authentication code so that user interaction is more 
abstracted out; replace loops structured around a single interaction
per loop with less tortuous code (fixes: `ki-multiprompt-crash',
`ssh1-bad-passphrase-crash'; makes `ssh2-password-expiry' and
`proxy-password-prompt' easier).

The new interaction abstraction has a lot of fields that are unused in
the current code (things like window captions); this is groundwork for
`gui-auth'. However, ssh.c still writes directly to stderr; that may
want to be fixed.

In the GUI apps, user interaction is moved to terminal.c. This should
make it easier to fix things like UTF-8 username entry, although I
haven't attempted to do so. Also, control character filtering can be
tailored to be appropriate for individual front-ends; so far I don't
promise anything other than not having made it any worse.

I've tried to test this fairly exhaustively (although Mac stuff is
untested, as usual). It all seems to basically work, but I bet there
are new bugs. (One I know about is that you can no longer make the
PuTTY window go away with a ^D at the password prompt; this should be
fixed.)

[originally from svn r6437]
[this svn revision also touched putty-wishlist]
2005-10-30 20:24:09 +00:00

831 lines
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/*
* PLink - a Windows command-line (stdin/stdout) variant of PuTTY.
*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <stdarg.h>
#define PUTTY_DO_GLOBALS /* actually _define_ globals */
#include "putty.h"
#include "storage.h"
#include "tree234.h"
#define WM_AGENT_CALLBACK (WM_APP + 4)
#define MAX_STDIN_BACKLOG 4096
struct agent_callback {
void (*callback)(void *, void *, int);
void *callback_ctx;
void *data;
int len;
};
void fatalbox(char *p, ...)
{
va_list ap;
fprintf(stderr, "FATAL ERROR: ");
va_start(ap, p);
vfprintf(stderr, p, ap);
va_end(ap);
fputc('\n', stderr);
cleanup_exit(1);
}
void modalfatalbox(char *p, ...)
{
va_list ap;
fprintf(stderr, "FATAL ERROR: ");
va_start(ap, p);
vfprintf(stderr, p, ap);
va_end(ap);
fputc('\n', stderr);
cleanup_exit(1);
}
void connection_fatal(void *frontend, char *p, ...)
{
va_list ap;
fprintf(stderr, "FATAL ERROR: ");
va_start(ap, p);
vfprintf(stderr, p, ap);
va_end(ap);
fputc('\n', stderr);
cleanup_exit(1);
}
void cmdline_error(char *p, ...)
{
va_list ap;
fprintf(stderr, "plink: ");
va_start(ap, p);
vfprintf(stderr, p, ap);
va_end(ap);
fputc('\n', stderr);
exit(1);
}
HANDLE inhandle, outhandle, errhandle;
DWORD orig_console_mode;
WSAEVENT netevent;
static Backend *back;
static void *backhandle;
static Config cfg;
int term_ldisc(Terminal *term, int mode)
{
return FALSE;
}
void ldisc_update(void *frontend, int echo, int edit)
{
/* Update stdin read mode to reflect changes in line discipline. */
DWORD mode;
mode = ENABLE_PROCESSED_INPUT;
if (echo)
mode = mode | ENABLE_ECHO_INPUT;
else
mode = mode & ~ENABLE_ECHO_INPUT;
if (edit)
mode = mode | ENABLE_LINE_INPUT;
else
mode = mode & ~ENABLE_LINE_INPUT;
SetConsoleMode(inhandle, mode);
}
char *get_ttymode(void *frontend, const char *mode) { return NULL; }
struct input_data {
DWORD len;
char buffer[4096];
HANDLE event, eventback;
};
static DWORD WINAPI stdin_read_thread(void *param)
{
struct input_data *idata = (struct input_data *) param;
HANDLE inhandle;
inhandle = GetStdHandle(STD_INPUT_HANDLE);
while (ReadFile(inhandle, idata->buffer, sizeof(idata->buffer),
&idata->len, NULL) && idata->len > 0) {
SetEvent(idata->event);
WaitForSingleObject(idata->eventback, INFINITE);
}
idata->len = 0;
SetEvent(idata->event);
return 0;
}
struct output_data {
DWORD len, lenwritten;
int writeret;
char *buffer;
int is_stderr, done;
HANDLE event, eventback;
int busy;
};
static DWORD WINAPI stdout_write_thread(void *param)
{
struct output_data *odata = (struct output_data *) param;
HANDLE outhandle, errhandle;
outhandle = GetStdHandle(STD_OUTPUT_HANDLE);
errhandle = GetStdHandle(STD_ERROR_HANDLE);
while (1) {
WaitForSingleObject(odata->eventback, INFINITE);
if (odata->done)
break;
odata->writeret =
WriteFile(odata->is_stderr ? errhandle : outhandle,
odata->buffer, odata->len, &odata->lenwritten, NULL);
SetEvent(odata->event);
}
return 0;
}
bufchain stdout_data, stderr_data;
struct output_data odata, edata;
void try_output(int is_stderr)
{
struct output_data *data = (is_stderr ? &edata : &odata);
void *senddata;
int sendlen;
if (!data->busy) {
bufchain_prefix(is_stderr ? &stderr_data : &stdout_data,
&senddata, &sendlen);
data->buffer = senddata;
data->len = sendlen;
SetEvent(data->eventback);
data->busy = 1;
}
}
int from_backend(void *frontend_handle, int is_stderr,
const char *data, int len)
{
int osize, esize;
if (is_stderr) {
bufchain_add(&stderr_data, data, len);
try_output(1);
} else {
bufchain_add(&stdout_data, data, len);
try_output(0);
}
osize = bufchain_size(&stdout_data);
esize = bufchain_size(&stderr_data);
return osize + esize;
}
int from_backend_untrusted(void *frontend_handle, const char *data, int len)
{
/*
* No "untrusted" output should get here (the way the code is
* currently, it's all diverted by FLAG_STDERR).
*/
assert(!"Unexpected call to from_backend_untrusted()");
return 0; /* not reached */
}
int get_userpass_input(prompts_t *p, unsigned char *in, int inlen)
{
int ret;
ret = cmdline_get_passwd_input(p, in, inlen);
if (ret == -1)
ret = console_get_userpass_input(p, in, inlen);
return ret;
}
static DWORD main_thread_id;
void agent_schedule_callback(void (*callback)(void *, void *, int),
void *callback_ctx, void *data, int len)
{
struct agent_callback *c = snew(struct agent_callback);
c->callback = callback;
c->callback_ctx = callback_ctx;
c->data = data;
c->len = len;
PostThreadMessage(main_thread_id, WM_AGENT_CALLBACK, 0, (LPARAM)c);
}
/*
* Short description of parameters.
*/
static void usage(void)
{
printf("PuTTY Link: command-line connection utility\n");
printf("%s\n", ver);
printf("Usage: plink [options] [user@]host [command]\n");
printf(" (\"host\" can also be a PuTTY saved session name)\n");
printf("Options:\n");
printf(" -V print version information and exit\n");
printf(" -pgpfp print PGP key fingerprints and exit\n");
printf(" -v show verbose messages\n");
printf(" -load sessname Load settings from saved session\n");
printf(" -ssh -telnet -rlogin -raw\n");
printf(" force use of a particular protocol\n");
printf(" -P port connect to specified port\n");
printf(" -l user connect with specified username\n");
printf(" -batch disable all interactive prompts\n");
printf("The following options only apply to SSH connections:\n");
printf(" -pw passw login with specified password\n");
printf(" -D [listen-IP:]listen-port\n");
printf(" Dynamic SOCKS-based port forwarding\n");
printf(" -L [listen-IP:]listen-port:host:port\n");
printf(" Forward local port to remote address\n");
printf(" -R [listen-IP:]listen-port:host:port\n");
printf(" Forward remote port to local address\n");
printf(" -X -x enable / disable X11 forwarding\n");
printf(" -A -a enable / disable agent forwarding\n");
printf(" -t -T enable / disable pty allocation\n");
printf(" -1 -2 force use of particular protocol version\n");
printf(" -4 -6 force use of IPv4 or IPv6\n");
printf(" -C enable compression\n");
printf(" -i key private key file for authentication\n");
printf(" -m file read remote command(s) from file\n");
printf(" -s remote command is an SSH subsystem (SSH-2 only)\n");
printf(" -N don't start a shell/command (SSH-2 only)\n");
exit(1);
}
static void version(void)
{
printf("plink: %s\n", ver);
exit(1);
}
char *do_select(SOCKET skt, int startup)
{
int events;
if (startup) {
events = (FD_CONNECT | FD_READ | FD_WRITE |
FD_OOB | FD_CLOSE | FD_ACCEPT);
} else {
events = 0;
}
if (p_WSAEventSelect(skt, netevent, events) == SOCKET_ERROR) {
switch (p_WSAGetLastError()) {
case WSAENETDOWN:
return "Network is down";
default:
return "WSAEventSelect(): unknown error";
}
}
return NULL;
}
int main(int argc, char **argv)
{
WSAEVENT stdinevent, stdoutevent, stderrevent;
HANDLE handles[4];
DWORD in_threadid, out_threadid, err_threadid;
struct input_data idata;
int reading = FALSE;
int sending;
int portnumber = -1;
SOCKET *sklist;
int skcount, sksize;
int connopen;
int exitcode;
int errors;
int use_subsystem = 0;
long now, next;
sklist = NULL;
skcount = sksize = 0;
/*
* Initialise port and protocol to sensible defaults. (These
* will be overridden by more or less anything.)
*/
default_protocol = PROT_SSH;
default_port = 22;
flags = FLAG_STDERR;
/*
* Process the command line.
*/
do_defaults(NULL, &cfg);
loaded_session = FALSE;
default_protocol = cfg.protocol;
default_port = cfg.port;
errors = 0;
{
/*
* Override the default protocol if PLINK_PROTOCOL is set.
*/
char *p = getenv("PLINK_PROTOCOL");
int i;
if (p) {
for (i = 0; backends[i].backend != NULL; i++) {
if (!strcmp(backends[i].name, p)) {
default_protocol = cfg.protocol = backends[i].protocol;
default_port = cfg.port =
backends[i].backend->default_port;
break;
}
}
}
}
while (--argc) {
char *p = *++argv;
if (*p == '-') {
int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
1, &cfg);
if (ret == -2) {
fprintf(stderr,
"plink: option \"%s\" requires an argument\n", p);
errors = 1;
} else if (ret == 2) {
--argc, ++argv;
} else if (ret == 1) {
continue;
} else if (!strcmp(p, "-batch")) {
console_batch_mode = 1;
} else if (!strcmp(p, "-s")) {
/* Save status to write to cfg later. */
use_subsystem = 1;
} else if (!strcmp(p, "-V")) {
version();
} else if (!strcmp(p, "-pgpfp")) {
pgp_fingerprints();
exit(1);
} else {
fprintf(stderr, "plink: unknown option \"%s\"\n", p);
errors = 1;
}
} else if (*p) {
if (!*cfg.host) {
char *q = p;
/*
* If the hostname starts with "telnet:", set the
* protocol to Telnet and process the string as a
* Telnet URL.
*/
if (!strncmp(q, "telnet:", 7)) {
char c;
q += 7;
if (q[0] == '/' && q[1] == '/')
q += 2;
cfg.protocol = PROT_TELNET;
p = q;
while (*p && *p != ':' && *p != '/')
p++;
c = *p;
if (*p)
*p++ = '\0';
if (c == ':')
cfg.port = atoi(p);
else
cfg.port = -1;
strncpy(cfg.host, q, sizeof(cfg.host) - 1);
cfg.host[sizeof(cfg.host) - 1] = '\0';
} else {
char *r, *user, *host;
/*
* Before we process the [user@]host string, we
* first check for the presence of a protocol
* prefix (a protocol name followed by ",").
*/
r = strchr(p, ',');
if (r) {
int i, j;
for (i = 0; backends[i].backend != NULL; i++) {
j = strlen(backends[i].name);
if (j == r - p &&
!memcmp(backends[i].name, p, j)) {
default_protocol = cfg.protocol =
backends[i].protocol;
portnumber =
backends[i].backend->default_port;
p = r + 1;
break;
}
}
}
/*
* A nonzero length string followed by an @ is treated
* as a username. (We discount an _initial_ @.) The
* rest of the string (or the whole string if no @)
* is treated as a session name and/or hostname.
*/
r = strrchr(p, '@');
if (r == p)
p++, r = NULL; /* discount initial @ */
if (r) {
*r++ = '\0';
user = p, host = r;
} else {
user = NULL, host = p;
}
/*
* Now attempt to load a saved session with the
* same name as the hostname.
*/
{
Config cfg2;
do_defaults(host, &cfg2);
if (loaded_session || cfg2.host[0] == '\0') {
/* No settings for this host; use defaults */
/* (or session was already loaded with -load) */
strncpy(cfg.host, host, sizeof(cfg.host) - 1);
cfg.host[sizeof(cfg.host) - 1] = '\0';
cfg.port = default_port;
} else {
cfg = cfg2;
}
}
if (user) {
/* Patch in specified username. */
strncpy(cfg.username, user,
sizeof(cfg.username) - 1);
cfg.username[sizeof(cfg.username) - 1] = '\0';
}
}
} else {
char *command;
int cmdlen, cmdsize;
cmdlen = cmdsize = 0;
command = NULL;
while (argc) {
while (*p) {
if (cmdlen >= cmdsize) {
cmdsize = cmdlen + 512;
command = sresize(command, cmdsize, char);
}
command[cmdlen++]=*p++;
}
if (cmdlen >= cmdsize) {
cmdsize = cmdlen + 512;
command = sresize(command, cmdsize, char);
}
command[cmdlen++]=' '; /* always add trailing space */
if (--argc) p = *++argv;
}
if (cmdlen) command[--cmdlen]='\0';
/* change trailing blank to NUL */
cfg.remote_cmd_ptr = command;
cfg.remote_cmd_ptr2 = NULL;
cfg.nopty = TRUE; /* command => no terminal */
break; /* done with cmdline */
}
}
}
if (errors)
return 1;
if (!*cfg.host) {
usage();
}
/*
* Trim leading whitespace off the hostname if it's there.
*/
{
int space = strspn(cfg.host, " \t");
memmove(cfg.host, cfg.host+space, 1+strlen(cfg.host)-space);
}
/* See if host is of the form user@host */
if (cfg.host[0] != '\0') {
char *atsign = strrchr(cfg.host, '@');
/* Make sure we're not overflowing the user field */
if (atsign) {
if (atsign - cfg.host < sizeof cfg.username) {
strncpy(cfg.username, cfg.host, atsign - cfg.host);
cfg.username[atsign - cfg.host] = '\0';
}
memmove(cfg.host, atsign + 1, 1 + strlen(atsign + 1));
}
}
/*
* Perform command-line overrides on session configuration.
*/
cmdline_run_saved(&cfg);
/*
* Apply subsystem status.
*/
if (use_subsystem)
cfg.ssh_subsys = TRUE;
/*
* Trim a colon suffix off the hostname if it's there.
*/
cfg.host[strcspn(cfg.host, ":")] = '\0';
/*
* Remove any remaining whitespace from the hostname.
*/
{
int p1 = 0, p2 = 0;
while (cfg.host[p2] != '\0') {
if (cfg.host[p2] != ' ' && cfg.host[p2] != '\t') {
cfg.host[p1] = cfg.host[p2];
p1++;
}
p2++;
}
cfg.host[p1] = '\0';
}
if (!cfg.remote_cmd_ptr && !*cfg.remote_cmd)
flags |= FLAG_INTERACTIVE;
/*
* Select protocol. This is farmed out into a table in a
* separate file to enable an ssh-free variant.
*/
{
int i;
back = NULL;
for (i = 0; backends[i].backend != NULL; i++)
if (backends[i].protocol == cfg.protocol) {
back = backends[i].backend;
break;
}
if (back == NULL) {
fprintf(stderr,
"Internal fault: Unsupported protocol found\n");
return 1;
}
}
/*
* Select port.
*/
if (portnumber != -1)
cfg.port = portnumber;
sk_init();
if (p_WSAEventSelect == NULL) {
fprintf(stderr, "Plink requires WinSock 2\n");
return 1;
}
/*
* Start up the connection.
*/
netevent = CreateEvent(NULL, FALSE, FALSE, NULL);
{
const char *error;
char *realhost;
/* nodelay is only useful if stdin is a character device (console) */
int nodelay = cfg.tcp_nodelay &&
(GetFileType(GetStdHandle(STD_INPUT_HANDLE)) == FILE_TYPE_CHAR);
error = back->init(NULL, &backhandle, &cfg, cfg.host, cfg.port,
&realhost, nodelay, cfg.tcp_keepalives);
if (error) {
fprintf(stderr, "Unable to open connection:\n%s", error);
return 1;
}
logctx = log_init(NULL, &cfg);
back->provide_logctx(backhandle, logctx);
console_provide_logctx(logctx);
sfree(realhost);
}
connopen = 1;
stdinevent = CreateEvent(NULL, FALSE, FALSE, NULL);
stdoutevent = CreateEvent(NULL, FALSE, FALSE, NULL);
stderrevent = CreateEvent(NULL, FALSE, FALSE, NULL);
inhandle = GetStdHandle(STD_INPUT_HANDLE);
outhandle = GetStdHandle(STD_OUTPUT_HANDLE);
errhandle = GetStdHandle(STD_ERROR_HANDLE);
/*
* Turn off ECHO and LINE input modes. We don't care if this
* call fails, because we know we aren't necessarily running in
* a console.
*/
GetConsoleMode(inhandle, &orig_console_mode);
SetConsoleMode(inhandle, ENABLE_PROCESSED_INPUT);
main_thread_id = GetCurrentThreadId();
handles[0] = netevent;
handles[1] = stdinevent;
handles[2] = stdoutevent;
handles[3] = stderrevent;
sending = FALSE;
/*
* Create spare threads to write to stdout and stderr, so we
* can arrange asynchronous writes.
*/
odata.event = stdoutevent;
odata.eventback = CreateEvent(NULL, FALSE, FALSE, NULL);
odata.is_stderr = 0;
odata.busy = odata.done = 0;
if (!CreateThread(NULL, 0, stdout_write_thread,
&odata, 0, &out_threadid)) {
fprintf(stderr, "Unable to create output thread\n");
cleanup_exit(1);
}
edata.event = stderrevent;
edata.eventback = CreateEvent(NULL, FALSE, FALSE, NULL);
edata.is_stderr = 1;
edata.busy = edata.done = 0;
if (!CreateThread(NULL, 0, stdout_write_thread,
&edata, 0, &err_threadid)) {
fprintf(stderr, "Unable to create error output thread\n");
cleanup_exit(1);
}
now = GETTICKCOUNT();
while (1) {
int n;
DWORD ticks;
if (!sending && back->sendok(backhandle)) {
/*
* Create a separate thread to read from stdin. This is
* a total pain, but I can't find another way to do it:
*
* - an overlapped ReadFile or ReadFileEx just doesn't
* happen; we get failure from ReadFileEx, and
* ReadFile blocks despite being given an OVERLAPPED
* structure. Perhaps we can't do overlapped reads
* on consoles. WHY THE HELL NOT?
*
* - WaitForMultipleObjects(netevent, console) doesn't
* work, because it signals the console when
* _anything_ happens, including mouse motions and
* other things that don't cause data to be readable
* - so we're back to ReadFile blocking.
*/
idata.event = stdinevent;
idata.eventback = CreateEvent(NULL, FALSE, FALSE, NULL);
if (!CreateThread(NULL, 0, stdin_read_thread,
&idata, 0, &in_threadid)) {
fprintf(stderr, "Unable to create input thread\n");
cleanup_exit(1);
}
sending = TRUE;
reading = TRUE;
}
if (run_timers(now, &next)) {
ticks = next - GETTICKCOUNT();
if (ticks < 0) ticks = 0; /* just in case */
} else {
ticks = INFINITE;
}
n = MsgWaitForMultipleObjects(4, handles, FALSE, ticks,
QS_POSTMESSAGE);
if (n == WAIT_OBJECT_0 + 0) {
WSANETWORKEVENTS things;
SOCKET socket;
extern SOCKET first_socket(int *), next_socket(int *);
extern int select_result(WPARAM, LPARAM);
int i, socketstate;
/*
* We must not call select_result() for any socket
* until we have finished enumerating within the tree.
* This is because select_result() may close the socket
* and modify the tree.
*/
/* Count the active sockets. */
i = 0;
for (socket = first_socket(&socketstate);
socket != INVALID_SOCKET;
socket = next_socket(&socketstate)) i++;
/* Expand the buffer if necessary. */
if (i > sksize) {
sksize = i + 16;
sklist = sresize(sklist, sksize, SOCKET);
}
/* Retrieve the sockets into sklist. */
skcount = 0;
for (socket = first_socket(&socketstate);
socket != INVALID_SOCKET;
socket = next_socket(&socketstate)) {
sklist[skcount++] = socket;
}
/* Now we're done enumerating; go through the list. */
for (i = 0; i < skcount; i++) {
WPARAM wp;
socket = sklist[i];
wp = (WPARAM) socket;
if (!p_WSAEnumNetworkEvents(socket, NULL, &things)) {
static const struct { int bit, mask; } eventtypes[] = {
{FD_CONNECT_BIT, FD_CONNECT},
{FD_READ_BIT, FD_READ},
{FD_CLOSE_BIT, FD_CLOSE},
{FD_OOB_BIT, FD_OOB},
{FD_WRITE_BIT, FD_WRITE},
{FD_ACCEPT_BIT, FD_ACCEPT},
};
int e;
noise_ultralight(socket);
noise_ultralight(things.lNetworkEvents);
for (e = 0; e < lenof(eventtypes); e++)
if (things.lNetworkEvents & eventtypes[e].mask) {
LPARAM lp;
int err = things.iErrorCode[eventtypes[e].bit];
lp = WSAMAKESELECTREPLY(eventtypes[e].mask, err);
connopen &= select_result(wp, lp);
}
}
}
} else if (n == WAIT_OBJECT_0 + 1) {
reading = 0;
noise_ultralight(idata.len);
if (connopen && back->socket(backhandle) != NULL) {
if (idata.len > 0) {
back->send(backhandle, idata.buffer, idata.len);
} else {
back->special(backhandle, TS_EOF);
}
}
} else if (n == WAIT_OBJECT_0 + 2) {
odata.busy = 0;
if (!odata.writeret) {
fprintf(stderr, "Unable to write to standard output\n");
cleanup_exit(0);
}
bufchain_consume(&stdout_data, odata.lenwritten);
if (bufchain_size(&stdout_data) > 0)
try_output(0);
if (connopen && back->socket(backhandle) != NULL) {
back->unthrottle(backhandle, bufchain_size(&stdout_data) +
bufchain_size(&stderr_data));
}
} else if (n == WAIT_OBJECT_0 + 3) {
edata.busy = 0;
if (!edata.writeret) {
fprintf(stderr, "Unable to write to standard output\n");
cleanup_exit(0);
}
bufchain_consume(&stderr_data, edata.lenwritten);
if (bufchain_size(&stderr_data) > 0)
try_output(1);
if (connopen && back->socket(backhandle) != NULL) {
back->unthrottle(backhandle, bufchain_size(&stdout_data) +
bufchain_size(&stderr_data));
}
} else if (n == WAIT_OBJECT_0 + 4) {
MSG msg;
while (PeekMessage(&msg, INVALID_HANDLE_VALUE,
WM_AGENT_CALLBACK, WM_AGENT_CALLBACK,
PM_REMOVE)) {
struct agent_callback *c = (struct agent_callback *)msg.lParam;
c->callback(c->callback_ctx, c->data, c->len);
sfree(c);
}
}
if (n == WAIT_TIMEOUT) {
now = next;
} else {
now = GETTICKCOUNT();
}
if (!reading && back->sendbuffer(backhandle) < MAX_STDIN_BACKLOG) {
SetEvent(idata.eventback);
reading = 1;
}
if ((!connopen || back->socket(backhandle) == NULL) &&
bufchain_size(&stdout_data) == 0 &&
bufchain_size(&stderr_data) == 0)
break; /* we closed the connection */
}
exitcode = back->exitcode(backhandle);
if (exitcode < 0) {
fprintf(stderr, "Remote process exit code unavailable\n");
exitcode = 1; /* this is an error condition */
}
cleanup_exit(exitcode);
return 0; /* placate compiler warning */
}
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