[u/mdw/putty] / console.c

/*
 * console.c: various interactive-prompt routines shared between
 * the console PuTTY tools
 */

#include <windows.h>

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

#include "putty.h"
#include "storage.h"
#include "ssh.h"

int console_batch_mode = FALSE;

static void *console_logctx = NULL;

/*
 * Clean up and exit.
 */
void cleanup_exit(int code)
{
    /*
     * Clean up.
     */
    sk_cleanup();
    WSACleanup();

    random_save_seed();
#ifdef MSCRYPTOAPI
    crypto_wrapup();
#endif

    exit(code);
}

void verify_ssh_host_key(void *frontend, char *host, int port, char *keytype,
			 char *keystr, char *fingerprint)
{
    int ret;
    HANDLE hin;
    DWORD savemode, i;

    static const char absentmsg_batch[] =
	"The server's host key is not cached in the registry. You\n"
	"have no guarantee that the server is the computer you\n"
	"think it is.\n"
	"The server's key fingerprint is:\n"
	"%s\n"
	"Connection abandoned.\n";
    static const char absentmsg[] =
	"The server's host key is not cached in the registry. You\n"
	"have no guarantee that the server is the computer you\n"
	"think it is.\n"
	"The server's key fingerprint is:\n"
	"%s\n"
	"If you trust this host, enter \"y\" to add the key to\n"
	"PuTTY's cache and carry on connecting.\n"
	"If you want to carry on connecting just once, without\n"
	"adding the key to the cache, enter \"n\".\n"
	"If you do not trust this host, press Return to abandon the\n"
	"connection.\n"
	"Store key in cache? (y/n) ";

    static const char wrongmsg_batch[] =
	"WARNING - POTENTIAL SECURITY BREACH!\n"
	"The server's host key does not match the one PuTTY has\n"
	"cached in the registry. This means that either the\n"
	"server administrator has changed the host key, or you\n"
	"have actually connected to another computer pretending\n"
	"to be the server.\n"
	"The new key fingerprint is:\n"
	"%s\n"
	"Connection abandoned.\n";
    static const char wrongmsg[] =
	"WARNING - POTENTIAL SECURITY BREACH!\n"
	"The server's host key does not match the one PuTTY has\n"
	"cached in the registry. This means that either the\n"
	"server administrator has changed the host key, or you\n"
	"have actually connected to another computer pretending\n"
	"to be the server.\n"
	"The new key fingerprint is:\n"
	"%s\n"
	"If you were expecting this change and trust the new key,\n"
	"enter \"y\" to update PuTTY's cache and continue connecting.\n"
	"If you want to carry on connecting but without updating\n"
	"the cache, enter \"n\".\n"
	"If you want to abandon the connection completely, press\n"
	"Return to cancel. Pressing Return is the ONLY guaranteed\n"
	"safe choice.\n"
	"Update cached key? (y/n, Return cancels connection) ";

    static const char abandoned[] = "Connection abandoned.\n";

    char line[32];

    /*
     * Verify the key against the registry.
     */
    ret = verify_host_key(host, port, keytype, keystr);

    if (ret == 0)		       /* success - key matched OK */
	return;

    if (ret == 2) {		       /* key was different */
	if (console_batch_mode) {
	    fprintf(stderr, wrongmsg_batch, fingerprint);
	    cleanup_exit(1);
	}
	fprintf(stderr, wrongmsg, fingerprint);
	fflush(stderr);
    }
    if (ret == 1) {		       /* key was absent */
	if (console_batch_mode) {
	    fprintf(stderr, absentmsg_batch, fingerprint);
	    cleanup_exit(1);
	}
	fprintf(stderr, absentmsg, fingerprint);
	fflush(stderr);
    }

    hin = GetStdHandle(STD_INPUT_HANDLE);
    GetConsoleMode(hin, &savemode);
    SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
			 ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
    ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
    SetConsoleMode(hin, savemode);

    if (line[0] != '\0' && line[0] != '\r' && line[0] != '\n') {
	if (line[0] == 'y' || line[0] == 'Y')
	    store_host_key(host, port, keytype, keystr);
    } else {
	fprintf(stderr, abandoned);
	cleanup_exit(0);
    }
}

void update_specials_menu(void *frontend)
{
}

/*
 * Ask whether the selected cipher is acceptable (since it was
 * below the configured 'warn' threshold).
 * cs: 0 = both ways, 1 = client->server, 2 = server->client
 */
void askcipher(void *frontend, char *ciphername, int cs)
{
    HANDLE hin;
    DWORD savemode, i;

    static const char msg[] =
	"The first %scipher supported by the server is\n"
	"%s, which is below the configured warning threshold.\n"
	"Continue with connection? (y/n) ";
    static const char msg_batch[] =
	"The first %scipher supported by the server is\n"
	"%s, which is below the configured warning threshold.\n"
	"Connection abandoned.\n";
    static const char abandoned[] = "Connection abandoned.\n";

    char line[32];

    if (console_batch_mode) {
	fprintf(stderr, msg_batch,
		(cs == 0) ? "" :
		(cs == 1) ? "client-to-server " : "server-to-client ",
		ciphername);
	cleanup_exit(1);
    }

    fprintf(stderr, msg,
	    (cs == 0) ? "" :
	    (cs == 1) ? "client-to-server " : "server-to-client ",
	    ciphername);
    fflush(stderr);

    hin = GetStdHandle(STD_INPUT_HANDLE);
    GetConsoleMode(hin, &savemode);
    SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
			 ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
    ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
    SetConsoleMode(hin, savemode);

    if (line[0] == 'y' || line[0] == 'Y') {
	return;
    } else {
	fprintf(stderr, abandoned);
	cleanup_exit(0);
    }
}

/*
 * Ask whether to wipe a session log file before writing to it.
 * Returns 2 for wipe, 1 for append, 0 for cancel (don't log).
 */
int askappend(void *frontend, Filename filename)
{
    HANDLE hin;
    DWORD savemode, i;

    static const char msgtemplate[] =
	"The session log file \"%.*s\" already exists.\n"
	"You can overwrite it with a new session log,\n"
	"append your session log to the end of it,\n"
	"or disable session logging for this session.\n"
	"Enter \"y\" to wipe the file, \"n\" to append to it,\n"
	"or just press Return to disable logging.\n"
	"Wipe the log file? (y/n, Return cancels logging) ";

    static const char msgtemplate_batch[] =
	"The session log file \"%.*s\" already exists.\n"
	"Logging will not be enabled.\n";

    char line[32];

    if (console_batch_mode) {
	fprintf(stderr, msgtemplate_batch, FILENAME_MAX, filename.path);
	fflush(stderr);
	return 0;
    }
    fprintf(stderr, msgtemplate, FILENAME_MAX, filename.path);
    fflush(stderr);

    hin = GetStdHandle(STD_INPUT_HANDLE);
    GetConsoleMode(hin, &savemode);
    SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
			 ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
    ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
    SetConsoleMode(hin, savemode);

    if (line[0] == 'y' || line[0] == 'Y')
	return 2;
    else if (line[0] == 'n' || line[0] == 'N')
	return 1;
    else
	return 0;
}

/*
 * Warn about the obsolescent key file format.
 * 
 * Uniquely among these functions, this one does _not_ expect a
 * frontend handle. This means that if PuTTY is ported to a
 * platform which requires frontend handles, this function will be
 * an anomaly. Fortunately, the problem it addresses will not have
 * been present on that platform, so it can plausibly be
 * implemented as an empty function.
 */
void old_keyfile_warning(void)
{
    static const char message[] =
	"You are loading an SSH 2 private key which has an\n"
	"old version of the file format. This means your key\n"
	"file is not fully tamperproof. Future versions of\n"
	"PuTTY may stop supporting this private key format,\n"
	"so we recommend you convert your key to the new\n"
	"format.\n"
	"\n"
	"Once the key is loaded into PuTTYgen, you can perform\n"
	"this conversion simply by saving it again.\n";

    fputs(message, stderr);
}

void console_provide_logctx(void *logctx)
{
    console_logctx = logctx;
}

void logevent(void *frontend, const char *string)
{
    if (console_logctx)
	log_eventlog(console_logctx, string);
}

int console_get_line(const char *prompt, char *str,
			    int maxlen, int is_pw)
{
    HANDLE hin, hout;
    DWORD savemode, newmode, i;

    if (console_batch_mode) {
	if (maxlen > 0)
	    str[0] = '\0';
    } else {
	hin = GetStdHandle(STD_INPUT_HANDLE);
	hout = GetStdHandle(STD_OUTPUT_HANDLE);
	if (hin == INVALID_HANDLE_VALUE || hout == INVALID_HANDLE_VALUE) {
	    fprintf(stderr, "Cannot get standard input/output handles\n");
	    cleanup_exit(1);
	}

	GetConsoleMode(hin, &savemode);
	newmode = savemode | ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT;
	if (is_pw)
	    newmode &= ~ENABLE_ECHO_INPUT;
	else
	    newmode |= ENABLE_ECHO_INPUT;
	SetConsoleMode(hin, newmode);

	WriteFile(hout, prompt, strlen(prompt), &i, NULL);
	ReadFile(hin, str, maxlen - 1, &i, NULL);

	SetConsoleMode(hin, savemode);

	if ((int) i > maxlen)
	    i = maxlen - 1;
	else
	    i = i - 2;
	str[i] = '\0';

	if (is_pw)
	    WriteFile(hout, "\r\n", 2, &i, NULL);

    }
    return 1;
}

void frontend_keypress(void *handle)
{
    /*
     * This is nothing but a stub, in console code.
     */
    return;
}
Commit	Line	Data
ff2ae367	1	/*
	2	* console.c: various interactive-prompt routines shared between
	3	* the console PuTTY tools
	4	*/
	5
	6	#include <windows.h>
	7
	8	#include <stdio.h>
	9	#include <stdlib.h>
	10	#include <stdarg.h>
	11
	12	#include "putty.h"
	13	#include "storage.h"
	14	#include "ssh.h"
	15
	16	int console_batch_mode = FALSE;
	17
d3fef4a5	18	static void *console_logctx = NULL;
d3fef4a5	19
93b581bd	20	/*
	21	* Clean up and exit.
	22	*/
	23	void cleanup_exit(int code)
	24	{
	25	/*
	26	* Clean up.
	27	*/
	28	sk_cleanup();
	29	WSACleanup();
	30
bf61b566	31	random_save_seed();
93b581bd	32	#ifdef MSCRYPTOAPI
bf61b566	33	crypto_wrapup();
93b581bd	34	#endif
93b581bd	35
	36	exit(code);
	37	}
	38
a8327734	39	void verify_ssh_host_key(void frontend, char host, int port, char *keytype,
ff2ae367	40	char keystr, char fingerprint)
	41	{
	42	int ret;
	43	HANDLE hin;
	44	DWORD savemode, i;
	45
	46	static const char absentmsg_batch[] =
	47	"The server's host key is not cached in the registry. You\n"
	48	"have no guarantee that the server is the computer you\n"
	49	"think it is.\n"
	50	"The server's key fingerprint is:\n"
	51	"%s\n"
	52	"Connection abandoned.\n";
	53	static const char absentmsg[] =
	54	"The server's host key is not cached in the registry. You\n"
	55	"have no guarantee that the server is the computer you\n"
	56	"think it is.\n"
	57	"The server's key fingerprint is:\n"
	58	"%s\n"
	59	"If you trust this host, enter \"y\" to add the key to\n"
	60	"PuTTY's cache and carry on connecting.\n"
	61	"If you want to carry on connecting just once, without\n"
	62	"adding the key to the cache, enter \"n\".\n"
	63	"If you do not trust this host, press Return to abandon the\n"
	64	"connection.\n"
	65	"Store key in cache? (y/n) ";
	66
	67	static const char wrongmsg_batch[] =
	68	"WARNING - POTENTIAL SECURITY BREACH!\n"
	69	"The server's host key does not match the one PuTTY has\n"
	70	"cached in the registry. This means that either the\n"
	71	"server administrator has changed the host key, or you\n"
	72	"have actually connected to another computer pretending\n"
	73	"to be the server.\n"
	74	"The new key fingerprint is:\n"
	75	"%s\n"
	76	"Connection abandoned.\n";
	77	static const char wrongmsg[] =
	78	"WARNING - POTENTIAL SECURITY BREACH!\n"
	79	"The server's host key does not match the one PuTTY has\n"
	80	"cached in the registry. This means that either the\n"
	81	"server administrator has changed the host key, or you\n"
	82	"have actually connected to another computer pretending\n"
	83	"to be the server.\n"
	84	"The new key fingerprint is:\n"
	85	"%s\n"
	86	"If you were expecting this change and trust the new key,\n"
	87	"enter \"y\" to update PuTTY's cache and continue connecting.\n"
	88	"If you want to carry on connecting but without updating\n"
	89	"the cache, enter \"n\".\n"
	90	"If you want to abandon the connection completely, press\n"
	91	"Return to cancel. Pressing Return is the ONLY guaranteed\n"
	92	"safe choice.\n"
	93	"Update cached key? (y/n, Return cancels connection) ";
	94
	95	static const char abandoned[] = "Connection abandoned.\n";
	96
	97	char line[32];
	98
	99	/*
	100	* Verify the key against the registry.
	101	*/
	102	ret = verify_host_key(host, port, keytype, keystr);
	103
104	if (ret == 0) /* success - key matched OK */
105	return;
106
107	if (ret == 2) { /* key was different */
108	if (console_batch_mode) {
109	fprintf(stderr, wrongmsg_batch, fingerprint);
93b581bd	110	cleanup_exit(1);
ff2ae367	111	}
	112	fprintf(stderr, wrongmsg, fingerprint);
	113	fflush(stderr);
	114	}
	115	if (ret == 1) { /* key was absent */
	116	if (console_batch_mode) {
	117	fprintf(stderr, absentmsg_batch, fingerprint);
93b581bd	118	cleanup_exit(1);
ff2ae367	119	}
	120	fprintf(stderr, absentmsg, fingerprint);
	121	fflush(stderr);
	122	}
	123
	124	hin = GetStdHandle(STD_INPUT_HANDLE);
	125	GetConsoleMode(hin, &savemode);
	126	SetConsoleMode(hin, (savemode \| ENABLE_ECHO_INPUT \|
	127	ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT));
	128	ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
	129	SetConsoleMode(hin, savemode);
	130
	131	if (line[0] != '\0' && line[0] != '\r' && line[0] != '\n') {
	132	if (line[0] == 'y' \|\| line[0] == 'Y')
	133	store_host_key(host, port, keytype, keystr);
	134	} else {
	135	fprintf(stderr, abandoned);
93b581bd	136	cleanup_exit(0);
ff2ae367	137	}
	138	}
	139
125105d1	140	void update_specials_menu(void *frontend)
	141	{
	142	}
	143
ff2ae367	144	/*
	145	* Ask whether the selected cipher is acceptable (since it was
	146	* below the configured 'warn' threshold).
	147	* cs: 0 = both ways, 1 = client->server, 2 = server->client
	148	*/
a8327734	149	void askcipher(void frontend, char ciphername, int cs)
ff2ae367	150	{
	151	HANDLE hin;
	152	DWORD savemode, i;
	153
	154	static const char msg[] =
	155	"The first %scipher supported by the server is\n"
	156	"%s, which is below the configured warning threshold.\n"
	157	"Continue with connection? (y/n) ";
	158	static const char msg_batch[] =
	159	"The first %scipher supported by the server is\n"
	160	"%s, which is below the configured warning threshold.\n"
	161	"Connection abandoned.\n";
	162	static const char abandoned[] = "Connection abandoned.\n";
	163
	164	char line[32];
	165
	166	if (console_batch_mode) {
	167	fprintf(stderr, msg_batch,
	168	(cs == 0) ? "" :
	169	(cs == 1) ? "client-to-server " : "server-to-client ",
	170	ciphername);
93b581bd	171	cleanup_exit(1);
ff2ae367	172	}
	173
	174	fprintf(stderr, msg,
	175	(cs == 0) ? "" :
	176	(cs == 1) ? "client-to-server " : "server-to-client ",
	177	ciphername);
	178	fflush(stderr);
	179
	180	hin = GetStdHandle(STD_INPUT_HANDLE);
	181	GetConsoleMode(hin, &savemode);
	182	SetConsoleMode(hin, (savemode \| ENABLE_ECHO_INPUT \|
	183	ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT));
	184	ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
	185	SetConsoleMode(hin, savemode);
	186
	187	if (line[0] == 'y' \|\| line[0] == 'Y') {
	188	return;
	189	} else {
	190	fprintf(stderr, abandoned);
93b581bd	191	cleanup_exit(0);
ff2ae367	192	}
	193	}
	194
	195	/*
	196	* Ask whether to wipe a session log file before writing to it.
	197	* Returns 2 for wipe, 1 for append, 0 for cancel (don't log).
	198	*/
9a30e26b	199	int askappend(void *frontend, Filename filename)
ff2ae367	200	{
	201	HANDLE hin;
	202	DWORD savemode, i;
	203
	204	static const char msgtemplate[] =
	205	"The session log file \"%.*s\" already exists.\n"
	206	"You can overwrite it with a new session log,\n"
	207	"append your session log to the end of it,\n"
	208	"or disable session logging for this session.\n"
	209	"Enter \"y\" to wipe the file, \"n\" to append to it,\n"
	210	"or just press Return to disable logging.\n"
	211	"Wipe the log file? (y/n, Return cancels logging) ";
	212
	213	static const char msgtemplate_batch[] =
	214	"The session log file \"%.*s\" already exists.\n"
	215	"Logging will not be enabled.\n";
	216
	217	char line[32];
	218
	219	if (console_batch_mode) {
9a30e26b	220	fprintf(stderr, msgtemplate_batch, FILENAME_MAX, filename.path);
ff2ae367	221	fflush(stderr);
	222	return 0;
	223	}
9a30e26b	224	fprintf(stderr, msgtemplate, FILENAME_MAX, filename.path);
ff2ae367	225	fflush(stderr);
	226
	227	hin = GetStdHandle(STD_INPUT_HANDLE);
	228	GetConsoleMode(hin, &savemode);
	229	SetConsoleMode(hin, (savemode \| ENABLE_ECHO_INPUT \|
	230	ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT));
	231	ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
	232	SetConsoleMode(hin, savemode);
	233
	234	if (line[0] == 'y' \|\| line[0] == 'Y')
	235	return 2;
	236	else if (line[0] == 'n' \|\| line[0] == 'N')
	237	return 1;
	238	else
	239	return 0;
	240	}
	241
	242	/*
	243	* Warn about the obsolescent key file format.
a8327734	244	*
	245	* Uniquely among these functions, this one does _not_ expect a
	246	* frontend handle. This means that if PuTTY is ported to a
	247	* platform which requires frontend handles, this function will be
	248	* an anomaly. Fortunately, the problem it addresses will not have
	249	* been present on that platform, so it can plausibly be
	250	* implemented as an empty function.
ff2ae367	251	*/
	252	void old_keyfile_warning(void)
	253	{
	254	static const char message[] =
	255	"You are loading an SSH 2 private key which has an\n"
	256	"old version of the file format. This means your key\n"
	257	"file is not fully tamperproof. Future versions of\n"
	258	"PuTTY may stop supporting this private key format,\n"
	259	"so we recommend you convert your key to the new\n"
	260	"format.\n"
	261	"\n"
	262	"Once the key is loaded into PuTTYgen, you can perform\n"
	263	"this conversion simply by saving it again.\n";
	264
	265	fputs(message, stderr);
	266	}
	267
d3fef4a5	268	void console_provide_logctx(void *logctx)
	269	{
	270	console_logctx = logctx;
	271	}
	272
cbe2d68f	273	void logevent(void frontend, const char string)
ff2ae367	274	{
d3fef4a5	275	if (console_logctx)
d3fef4a5	276	log_eventlog(console_logctx, string);
ff2ae367	277	}
ff2ae367	278
ff2ae367	279	int console_get_line(const char prompt, char str,
	280	int maxlen, int is_pw)
	281	{
	282	HANDLE hin, hout;
	283	DWORD savemode, newmode, i;
	284
ff2ae367	285	if (console_batch_mode) {
	286	if (maxlen > 0)
	287	str[0] = '\0';
	288	} else {
	289	hin = GetStdHandle(STD_INPUT_HANDLE);
	290	hout = GetStdHandle(STD_OUTPUT_HANDLE);
	291	if (hin == INVALID_HANDLE_VALUE \|\| hout == INVALID_HANDLE_VALUE) {
	292	fprintf(stderr, "Cannot get standard input/output handles\n");
93b581bd	293	cleanup_exit(1);
ff2ae367	294	}
	295
	296	GetConsoleMode(hin, &savemode);
	297	newmode = savemode \| ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT;
	298	if (is_pw)
	299	newmode &= ~ENABLE_ECHO_INPUT;
	300	else
	301	newmode \|= ENABLE_ECHO_INPUT;
	302	SetConsoleMode(hin, newmode);
	303
	304	WriteFile(hout, prompt, strlen(prompt), &i, NULL);
	305	ReadFile(hin, str, maxlen - 1, &i, NULL);
	306
	307	SetConsoleMode(hin, savemode);
	308
	309	if ((int) i > maxlen)
	310	i = maxlen - 1;
	311	else
	312	i = i - 2;
	313	str[i] = '\0';
	314
	315	if (is_pw)
	316	WriteFile(hout, "\r\n", 2, &i, NULL);
	317
	318	}
	319	return 1;
	320	}
f8255dce	321
b9d7bcad	322	void frontend_keypress(void *handle)
f8255dce	323	{
	324	/*
	325	* This is nothing but a stub, in console code.
	326	*/
	327	return;
	328	}