Ensure our network layer is properly cleaned up before PuTTY exits.
[u/mdw/putty] / console.c
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
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
39 void verify_ssh_host_key(char *host, int port, char *keytype,
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);
110 cleanup_exit(1);
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);
118 cleanup_exit(1);
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);
136 cleanup_exit(0);
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 */
145 void askcipher(char *ciphername, int cs)
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);
167 cleanup_exit(1);
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);
187 cleanup_exit(0);
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 */
195 int askappend(char *filename)
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
215 if (console_batch_mode) {
216 fprintf(stderr, msgtemplate_batch, FILENAME_MAX, filename);
217 fflush(stderr);
218 return 0;
219 }
220 fprintf(stderr, msgtemplate, FILENAME_MAX, filename);
221 fflush(stderr);
222
223 hin = GetStdHandle(STD_INPUT_HANDLE);
224 GetConsoleMode(hin, &savemode);
225 SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
226 ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
227 ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
228 SetConsoleMode(hin, savemode);
229
230 if (line[0] == 'y' || line[0] == 'Y')
231 return 2;
232 else if (line[0] == 'n' || line[0] == 'N')
233 return 1;
234 else
235 return 0;
236 }
237
238 /*
239 * Warn about the obsolescent key file format.
240 */
241 void old_keyfile_warning(void)
242 {
243 static const char message[] =
244 "You are loading an SSH 2 private key which has an\n"
245 "old version of the file format. This means your key\n"
246 "file is not fully tamperproof. Future versions of\n"
247 "PuTTY may stop supporting this private key format,\n"
248 "so we recommend you convert your key to the new\n"
249 "format.\n"
250 "\n"
251 "Once the key is loaded into PuTTYgen, you can perform\n"
252 "this conversion simply by saving it again.\n";
253
254 fputs(message, stderr);
255 }
256
257 void logevent(char *string)
258 {
259 }
260
261 char *console_password = NULL;
262
263 int console_get_line(const char *prompt, char *str,
264 int maxlen, int is_pw)
265 {
266 HANDLE hin, hout;
267 DWORD savemode, newmode, i;
268
269 if (is_pw && console_password) {
270 static int tried_once = 0;
271
272 if (tried_once) {
273 return 0;
274 } else {
275 strncpy(str, console_password, maxlen);
276 str[maxlen - 1] = '\0';
277 tried_once = 1;
278 return 1;
279 }
280 }
281
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");
290 cleanup_exit(1);
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 }