[u/mdw/putty] / windows / wincons.c

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

#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();

    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 %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 %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 %s 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 %s 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, keytype, fingerprint);
	    cleanup_exit(1);
	}
	fprintf(stderr, wrongmsg, keytype, fingerprint);
	fflush(stderr);
    }
    if (ret == 1) {		       /* key was absent */
	if (console_batch_mode) {
	    fprintf(stderr, absentmsg_batch, keytype, fingerprint);
	    cleanup_exit(1);
	}
	fprintf(stderr, absentmsg, keytype, 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	/*
ff2ae367	2	* console.c: various interactive-prompt routines shared between
f4ff9455	3	* the Windows console PuTTY tools
ff2ae367	4	*/
ff2ae367	5
ff2ae367	6	#include <stdio.h>
	7	#include <stdlib.h>
	8	#include <stdarg.h>
	9
	10	#include "putty.h"
	11	#include "storage.h"
	12	#include "ssh.h"
	13
	14	int console_batch_mode = FALSE;
	15
d3fef4a5	16	static void *console_logctx = NULL;
d3fef4a5	17
93b581bd	18	/*
	19	* Clean up and exit.
	20	*/
	21	void cleanup_exit(int code)
	22	{
	23	/*
	24	* Clean up.
	25	*/
	26	sk_cleanup();
93b581bd	27
bf61b566	28	random_save_seed();
93b581bd	29	#ifdef MSCRYPTOAPI
bf61b566	30	crypto_wrapup();
93b581bd	31	#endif
93b581bd	32
	33	exit(code);
	34	}
	35
a8327734	36	void verify_ssh_host_key(void frontend, char host, int port, char *keytype,
ff2ae367	37	char keystr, char fingerprint)
	38	{
	39	int ret;
	40	HANDLE hin;
	41	DWORD savemode, i;
	42
	43	static const char absentmsg_batch[] =
	44	"The server's host key is not cached in the registry. You\n"
	45	"have no guarantee that the server is the computer you\n"
	46	"think it is.\n"
65f66c88	47	"The server's %s key fingerprint is:\n"
ff2ae367	48	"%s\n"
	49	"Connection abandoned.\n";
	50	static const char absentmsg[] =
	51	"The server's host key is not cached in the registry. You\n"
	52	"have no guarantee that the server is the computer you\n"
	53	"think it is.\n"
65f66c88	54	"The server's %s key fingerprint is:\n"
ff2ae367	55	"%s\n"
	56	"If you trust this host, enter \"y\" to add the key to\n"
	57	"PuTTY's cache and carry on connecting.\n"
	58	"If you want to carry on connecting just once, without\n"
	59	"adding the key to the cache, enter \"n\".\n"
	60	"If you do not trust this host, press Return to abandon the\n"
	61	"connection.\n"
	62	"Store key in cache? (y/n) ";
	63
	64	static const char wrongmsg_batch[] =
	65	"WARNING - POTENTIAL SECURITY BREACH!\n"
	66	"The server's host key does not match the one PuTTY has\n"
	67	"cached in the registry. This means that either the\n"
	68	"server administrator has changed the host key, or you\n"
	69	"have actually connected to another computer pretending\n"
	70	"to be the server.\n"
65f66c88	71	"The new %s key fingerprint is:\n"
ff2ae367	72	"%s\n"
	73	"Connection abandoned.\n";
	74	static const char wrongmsg[] =
	75	"WARNING - POTENTIAL SECURITY BREACH!\n"
	76	"The server's host key does not match the one PuTTY has\n"
	77	"cached in the registry. This means that either the\n"
	78	"server administrator has changed the host key, or you\n"
	79	"have actually connected to another computer pretending\n"
	80	"to be the server.\n"
65f66c88	81	"The new %s key fingerprint is:\n"
ff2ae367	82	"%s\n"
	83	"If you were expecting this change and trust the new key,\n"
	84	"enter \"y\" to update PuTTY's cache and continue connecting.\n"
	85	"If you want to carry on connecting but without updating\n"
	86	"the cache, enter \"n\".\n"
	87	"If you want to abandon the connection completely, press\n"
	88	"Return to cancel. Pressing Return is the ONLY guaranteed\n"
	89	"safe choice.\n"
	90	"Update cached key? (y/n, Return cancels connection) ";
	91
	92	static const char abandoned[] = "Connection abandoned.\n";
	93
	94	char line[32];
	95
	96	/*
	97	* Verify the key against the registry.
	98	*/
	99	ret = verify_host_key(host, port, keytype, keystr);
	100
	101	if (ret == 0) /* success - key matched OK */
	102	return;
	103
	104	if (ret == 2) { /* key was different */
	105	if (console_batch_mode) {
65f66c88	106	fprintf(stderr, wrongmsg_batch, keytype, fingerprint);
93b581bd	107	cleanup_exit(1);
ff2ae367	108	}
65f66c88	109	fprintf(stderr, wrongmsg, keytype, fingerprint);
ff2ae367	110	fflush(stderr);
	111	}
	112	if (ret == 1) { /* key was absent */
	113	if (console_batch_mode) {
65f66c88	114	fprintf(stderr, absentmsg_batch, keytype, fingerprint);
93b581bd	115	cleanup_exit(1);
ff2ae367	116	}
65f66c88	117	fprintf(stderr, absentmsg, keytype, fingerprint);
ff2ae367	118	fflush(stderr);
	119	}
	120
	121	hin = GetStdHandle(STD_INPUT_HANDLE);
	122	GetConsoleMode(hin, &savemode);
	123	SetConsoleMode(hin, (savemode \| ENABLE_ECHO_INPUT \|
	124	ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT));
	125	ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
	126	SetConsoleMode(hin, savemode);
	127
	128	if (line[0] != '\0' && line[0] != '\r' && line[0] != '\n') {
	129	if (line[0] == 'y' \|\| line[0] == 'Y')
	130	store_host_key(host, port, keytype, keystr);
	131	} else {
	132	fprintf(stderr, abandoned);
93b581bd	133	cleanup_exit(0);
ff2ae367	134	}
	135	}
	136
125105d1	137	void update_specials_menu(void *frontend)
	138	{
	139	}
	140
ff2ae367	141	/*
	142	* Ask whether the selected cipher is acceptable (since it was
	143	* below the configured 'warn' threshold).
	144	* cs: 0 = both ways, 1 = client->server, 2 = server->client
	145	*/
a8327734	146	void askcipher(void frontend, char ciphername, int cs)
ff2ae367	147	{
	148	HANDLE hin;
	149	DWORD savemode, i;
	150
	151	static const char msg[] =
	152	"The first %scipher supported by the server is\n"
	153	"%s, which is below the configured warning threshold.\n"
	154	"Continue with connection? (y/n) ";
	155	static const char msg_batch[] =
	156	"The first %scipher supported by the server is\n"
	157	"%s, which is below the configured warning threshold.\n"
	158	"Connection abandoned.\n";
	159	static const char abandoned[] = "Connection abandoned.\n";
	160
	161	char line[32];
	162
	163	if (console_batch_mode) {
	164	fprintf(stderr, msg_batch,
	165	(cs == 0) ? "" :
	166	(cs == 1) ? "client-to-server " : "server-to-client ",
	167	ciphername);
93b581bd	168	cleanup_exit(1);
ff2ae367	169	}
	170
	171	fprintf(stderr, msg,
	172	(cs == 0) ? "" :
	173	(cs == 1) ? "client-to-server " : "server-to-client ",
	174	ciphername);
	175	fflush(stderr);
	176
	177	hin = GetStdHandle(STD_INPUT_HANDLE);
	178	GetConsoleMode(hin, &savemode);
	179	SetConsoleMode(hin, (savemode \| ENABLE_ECHO_INPUT \|
	180	ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT));
	181	ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
	182	SetConsoleMode(hin, savemode);
	183
	184	if (line[0] == 'y' \|\| line[0] == 'Y') {
	185	return;
	186	} else {
	187	fprintf(stderr, abandoned);
93b581bd	188	cleanup_exit(0);
ff2ae367	189	}
	190	}
	191
	192	/*
	193	* Ask whether to wipe a session log file before writing to it.
	194	* Returns 2 for wipe, 1 for append, 0 for cancel (don't log).
	195	*/
9a30e26b	196	int askappend(void *frontend, Filename filename)
ff2ae367	197	{
	198	HANDLE hin;
	199	DWORD savemode, i;
	200
	201	static const char msgtemplate[] =
	202	"The session log file \"%.*s\" already exists.\n"
	203	"You can overwrite it with a new session log,\n"
	204	"append your session log to the end of it,\n"
	205	"or disable session logging for this session.\n"
	206	"Enter \"y\" to wipe the file, \"n\" to append to it,\n"
	207	"or just press Return to disable logging.\n"
	208	"Wipe the log file? (y/n, Return cancels logging) ";
	209
	210	static const char msgtemplate_batch[] =
	211	"The session log file \"%.*s\" already exists.\n"
	212	"Logging will not be enabled.\n";
	213
	214	char line[32];
	215
	216	if (console_batch_mode) {
9a30e26b	217	fprintf(stderr, msgtemplate_batch, FILENAME_MAX, filename.path);
ff2ae367	218	fflush(stderr);
	219	return 0;
	220	}
9a30e26b	221	fprintf(stderr, msgtemplate, FILENAME_MAX, filename.path);
ff2ae367	222	fflush(stderr);
	223
	224	hin = GetStdHandle(STD_INPUT_HANDLE);
	225	GetConsoleMode(hin, &savemode);
	226	SetConsoleMode(hin, (savemode \| ENABLE_ECHO_INPUT \|
	227	ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT));
	228	ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
	229	SetConsoleMode(hin, savemode);
	230
	231	if (line[0] == 'y' \|\| line[0] == 'Y')
	232	return 2;
	233	else if (line[0] == 'n' \|\| line[0] == 'N')
	234	return 1;
	235	else
	236	return 0;
	237	}
	238
	239	/*
	240	* Warn about the obsolescent key file format.
a8327734	241	*
	242	* Uniquely among these functions, this one does _not_ expect a
	243	* frontend handle. This means that if PuTTY is ported to a
	244	* platform which requires frontend handles, this function will be
	245	* an anomaly. Fortunately, the problem it addresses will not have
	246	* been present on that platform, so it can plausibly be
	247	* implemented as an empty function.
ff2ae367	248	*/
	249	void old_keyfile_warning(void)
	250	{
	251	static const char message[] =
	252	"You are loading an SSH 2 private key which has an\n"
	253	"old version of the file format. This means your key\n"
	254	"file is not fully tamperproof. Future versions of\n"
	255	"PuTTY may stop supporting this private key format,\n"
	256	"so we recommend you convert your key to the new\n"
	257	"format.\n"
	258	"\n"
	259	"Once the key is loaded into PuTTYgen, you can perform\n"
	260	"this conversion simply by saving it again.\n";
	261
	262	fputs(message, stderr);
	263	}
	264
d3fef4a5	265	void console_provide_logctx(void *logctx)
	266	{
	267	console_logctx = logctx;
	268	}
	269
cbe2d68f	270	void logevent(void frontend, const char string)
ff2ae367	271	{
d3fef4a5	272	if (console_logctx)
d3fef4a5	273	log_eventlog(console_logctx, string);
ff2ae367	274	}
ff2ae367	275
ff2ae367	276	int console_get_line(const char prompt, char str,
	277	int maxlen, int is_pw)
	278	{
	279	HANDLE hin, hout;
	280	DWORD savemode, newmode, i;
	281
ff2ae367	282	if (console_batch_mode) {
	283	if (maxlen > 0)
	284	str[0] = '\0';
	285	} else {
	286	hin = GetStdHandle(STD_INPUT_HANDLE);
	287	hout = GetStdHandle(STD_OUTPUT_HANDLE);
	288	if (hin == INVALID_HANDLE_VALUE \|\| hout == INVALID_HANDLE_VALUE) {
	289	fprintf(stderr, "Cannot get standard input/output handles\n");
93b581bd	290	cleanup_exit(1);
ff2ae367	291	}
	292
	293	GetConsoleMode(hin, &savemode);
	294	newmode = savemode \| ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT;
	295	if (is_pw)
	296	newmode &= ~ENABLE_ECHO_INPUT;
	297	else
	298	newmode \|= ENABLE_ECHO_INPUT;
	299	SetConsoleMode(hin, newmode);
	300
	301	WriteFile(hout, prompt, strlen(prompt), &i, NULL);
	302	ReadFile(hin, str, maxlen - 1, &i, NULL);
	303
	304	SetConsoleMode(hin, savemode);
	305
	306	if ((int) i > maxlen)
	307	i = maxlen - 1;
	308	else
	309	i = i - 2;
	310	str[i] = '\0';
	311
	312	if (is_pw)
	313	WriteFile(hout, "\r\n", 2, &i, NULL);
	314
	315	}
	316	return 1;
	317	}
f8255dce	318
b9d7bcad	319	void frontend_keypress(void *handle)
f8255dce	320	{
	321	/*
	322	* This is nothing but a stub, in console code.
	323	*/
	324	return;
	325	}