[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;

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

    if (cfg.protocol == PROT_SSH) {
	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);
    }
}

/*
 * 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, char *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 (cfg.logxfovr != LGXF_ASK) {
	return ((cfg.logxfovr == LGXF_OVR) ? 2 : 1);
    }
    if (console_batch_mode) {
	fprintf(stderr, msgtemplate_batch, FILENAME_MAX, filename);
	fflush(stderr);
	return 0;
    }
    fprintf(stderr, msgtemplate, FILENAME_MAX, filename);
    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 logevent(void *frontend, char *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
93b581bd	18	/*
	19	* Clean up and exit.
	20	*/
	21	void cleanup_exit(int code)
	22	{
	23	/*
	24	* Clean up.
	25	*/
	26	sk_cleanup();
	27	WSACleanup();
	28
	29	if (cfg.protocol == PROT_SSH) {
	30	random_save_seed();
	31	#ifdef MSCRYPTOAPI
	32	crypto_wrapup();
	33	#endif
	34	}
	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
	140	/*
	141	* Ask whether the selected cipher is acceptable (since it was
	142	* below the configured 'warn' threshold).
	143	* cs: 0 = both ways, 1 = client->server, 2 = server->client
	144	*/
a8327734	145	void askcipher(void frontend, char ciphername, int cs)
ff2ae367	146	{
	147	HANDLE hin;
	148	DWORD savemode, i;
	149
	150	static const char msg[] =
	151	"The first %scipher supported by the server is\n"
	152	"%s, which is below the configured warning threshold.\n"
	153	"Continue with connection? (y/n) ";
	154	static const char msg_batch[] =
	155	"The first %scipher supported by the server is\n"
	156	"%s, which is below the configured warning threshold.\n"
	157	"Connection abandoned.\n";
	158	static const char abandoned[] = "Connection abandoned.\n";
	159
	160	char line[32];
	161
	162	if (console_batch_mode) {
	163	fprintf(stderr, msg_batch,
	164	(cs == 0) ? "" :
	165	(cs == 1) ? "client-to-server " : "server-to-client ",
	166	ciphername);
93b581bd	167	cleanup_exit(1);
ff2ae367	168	}
	169
	170	fprintf(stderr, msg,
	171	(cs == 0) ? "" :
	172	(cs == 1) ? "client-to-server " : "server-to-client ",
	173	ciphername);
	174	fflush(stderr);
	175
	176	hin = GetStdHandle(STD_INPUT_HANDLE);
	177	GetConsoleMode(hin, &savemode);
	178	SetConsoleMode(hin, (savemode \| ENABLE_ECHO_INPUT \|
	179	ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT));
	180	ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
	181	SetConsoleMode(hin, savemode);
	182
	183	if (line[0] == 'y' \|\| line[0] == 'Y') {
	184	return;
	185	} else {
	186	fprintf(stderr, abandoned);
93b581bd	187	cleanup_exit(0);
ff2ae367	188	}
	189	}
	190
	191	/*
	192	* Ask whether to wipe a session log file before writing to it.
	193	* Returns 2 for wipe, 1 for append, 0 for cancel (don't log).
	194	*/
a8327734	195	int askappend(void frontend, char filename)
ff2ae367	196	{
	197	HANDLE hin;
	198	DWORD savemode, i;
	199
	200	static const char msgtemplate[] =
	201	"The session log file \"%.*s\" already exists.\n"
	202	"You can overwrite it with a new session log,\n"
	203	"append your session log to the end of it,\n"
	204	"or disable session logging for this session.\n"
	205	"Enter \"y\" to wipe the file, \"n\" to append to it,\n"
	206	"or just press Return to disable logging.\n"
	207	"Wipe the log file? (y/n, Return cancels logging) ";
	208
	209	static const char msgtemplate_batch[] =
	210	"The session log file \"%.*s\" already exists.\n"
	211	"Logging will not be enabled.\n";
	212
	213	char line[32];
	214
361b81c1	215	if (cfg.logxfovr != LGXF_ASK) {
	216	return ((cfg.logxfovr == LGXF_OVR) ? 2 : 1);
	217	}
ff2ae367	218	if (console_batch_mode) {
	219	fprintf(stderr, msgtemplate_batch, FILENAME_MAX, filename);
	220	fflush(stderr);
	221	return 0;
	222	}
	223	fprintf(stderr, msgtemplate, FILENAME_MAX, filename);
	224	fflush(stderr);
	225
	226	hin = GetStdHandle(STD_INPUT_HANDLE);
	227	GetConsoleMode(hin, &savemode);
	228	SetConsoleMode(hin, (savemode \| ENABLE_ECHO_INPUT \|
	229	ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT));
	230	ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
	231	SetConsoleMode(hin, savemode);
	232
	233	if (line[0] == 'y' \|\| line[0] == 'Y')
	234	return 2;
	235	else if (line[0] == 'n' \|\| line[0] == 'N')
	236	return 1;
	237	else
	238	return 0;
	239	}
	240
	241	/*
	242	* Warn about the obsolescent key file format.
a8327734	243	*
	244	* Uniquely among these functions, this one does _not_ expect a
	245	* frontend handle. This means that if PuTTY is ported to a
	246	* platform which requires frontend handles, this function will be
	247	* an anomaly. Fortunately, the problem it addresses will not have
	248	* been present on that platform, so it can plausibly be
	249	* implemented as an empty function.
ff2ae367	250	*/
	251	void old_keyfile_warning(void)
	252	{
	253	static const char message[] =
	254	"You are loading an SSH 2 private key which has an\n"
	255	"old version of the file format. This means your key\n"
	256	"file is not fully tamperproof. Future versions of\n"
	257	"PuTTY may stop supporting this private key format,\n"
	258	"so we recommend you convert your key to the new\n"
	259	"format.\n"
	260	"\n"
	261	"Once the key is loaded into PuTTYgen, you can perform\n"
	262	"this conversion simply by saving it again.\n";
	263
	264	fputs(message, stderr);
	265	}
	266
a8327734	267	void logevent(void frontend, char string)
ff2ae367	268	{
	269	}
	270
ff2ae367	271	int console_get_line(const char prompt, char str,
	272	int maxlen, int is_pw)
	273	{
	274	HANDLE hin, hout;
	275	DWORD savemode, newmode, i;
	276
ff2ae367	277	if (console_batch_mode) {
	278	if (maxlen > 0)
	279	str[0] = '\0';
	280	} else {
	281	hin = GetStdHandle(STD_INPUT_HANDLE);
	282	hout = GetStdHandle(STD_OUTPUT_HANDLE);
	283	if (hin == INVALID_HANDLE_VALUE \|\| hout == INVALID_HANDLE_VALUE) {
	284	fprintf(stderr, "Cannot get standard input/output handles\n");
93b581bd	285	cleanup_exit(1);
ff2ae367	286	}
	287
	288	GetConsoleMode(hin, &savemode);
	289	newmode = savemode \| ENABLE_PROCESSED_INPUT \| ENABLE_LINE_INPUT;
	290	if (is_pw)
	291	newmode &= ~ENABLE_ECHO_INPUT;
	292	else
	293	newmode \|= ENABLE_ECHO_INPUT;
	294	SetConsoleMode(hin, newmode);
	295
	296	WriteFile(hout, prompt, strlen(prompt), &i, NULL);
	297	ReadFile(hin, str, maxlen - 1, &i, NULL);
	298
	299	SetConsoleMode(hin, savemode);
	300
	301	if ((int) i > maxlen)
	302	i = maxlen - 1;
	303	else
	304	i = i - 2;
	305	str[i] = '\0';
	306
	307	if (is_pw)
	308	WriteFile(hout, "\r\n", 2, &i, NULL);
	309
	310	}
	311	return 1;
	312	}
f8255dce	313
b9d7bcad	314	void frontend_keypress(void *handle)
f8255dce	315	{
	316	/*
	317	* This is nothing but a stub, in console code.
	318	*/
	319	return;
	320	}