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1 | /* |
2 | * uxcons.c: various interactive-prompt routines shared between the |
3 | * Unix console PuTTY tools |
4 | */ |
5 | |
6 | #include <stdio.h> |
7 | #include <stdlib.h> |
8 | #include <stdarg.h> |
9 | #include <assert.h> |
10 | #include <termios.h> |
11 | #include <unistd.h> |
12 | |
13 | #include "putty.h" |
14 | #include "storage.h" |
15 | #include "ssh.h" |
16 | |
17 | int console_batch_mode = FALSE; |
18 | |
19 | /* |
20 | * Clean up and exit. |
21 | */ |
22 | void cleanup_exit(int code) |
23 | { |
24 | /* |
25 | * Clean up. |
26 | */ |
27 | sk_cleanup(); |
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28 | random_save_seed(); |
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29 | exit(code); |
30 | } |
31 | |
32 | void verify_ssh_host_key(void *frontend, char *host, int port, char *keytype, |
33 | char *keystr, char *fingerprint) |
34 | { |
35 | int ret; |
36 | |
37 | static const char absentmsg_batch[] = |
38 | "The server's host key is not cached. You have no guarantee\n" |
39 | "that the server is the computer you think it is.\n" |
40 | "The server's key fingerprint is:\n" |
41 | "%s\n" |
42 | "Connection abandoned.\n"; |
43 | static const char absentmsg[] = |
44 | "The server's host key is not cached. You have no guarantee\n" |
45 | "that the server is the computer you think it is.\n" |
46 | "The server's key fingerprint is:\n" |
47 | "%s\n" |
48 | "If you trust this host, enter \"y\" to add the key to\n" |
49 | "PuTTY's cache and carry on connecting.\n" |
50 | "If you want to carry on connecting just once, without\n" |
51 | "adding the key to the cache, enter \"n\".\n" |
52 | "If you do not trust this host, press Return to abandon the\n" |
53 | "connection.\n" |
54 | "Store key in cache? (y/n) "; |
55 | |
56 | static const char wrongmsg_batch[] = |
57 | "WARNING - POTENTIAL SECURITY BREACH!\n" |
58 | "The server's host key does not match the one PuTTY has\n" |
59 | "cached. This means that either the server administrator\n" |
60 | "has changed the host key, or you have actually connected\n" |
61 | "to another computer pretending to be the server.\n" |
62 | "The new key fingerprint is:\n" |
63 | "%s\n" |
64 | "Connection abandoned.\n"; |
65 | static const char wrongmsg[] = |
66 | "WARNING - POTENTIAL SECURITY BREACH!\n" |
67 | "The server's host key does not match the one PuTTY has\n" |
68 | "cached. This means that either the server administrator\n" |
69 | "has changed the host key, or you have actually connected\n" |
70 | "to another computer pretending to be the server.\n" |
71 | "The new key fingerprint is:\n" |
72 | "%s\n" |
73 | "If you were expecting this change and trust the new key,\n" |
74 | "enter \"y\" to update PuTTY's cache and continue connecting.\n" |
75 | "If you want to carry on connecting but without updating\n" |
76 | "the cache, enter \"n\".\n" |
77 | "If you want to abandon the connection completely, press\n" |
78 | "Return to cancel. Pressing Return is the ONLY guaranteed\n" |
79 | "safe choice.\n" |
80 | "Update cached key? (y/n, Return cancels connection) "; |
81 | |
82 | static const char abandoned[] = "Connection abandoned.\n"; |
83 | |
84 | char line[32]; |
85 | |
86 | /* |
87 | * Verify the key. |
88 | */ |
89 | ret = verify_host_key(host, port, keytype, keystr); |
90 | |
91 | if (ret == 0) /* success - key matched OK */ |
92 | return; |
93 | |
94 | if (ret == 2) { /* key was different */ |
95 | if (console_batch_mode) { |
96 | fprintf(stderr, wrongmsg_batch, fingerprint); |
97 | cleanup_exit(1); |
98 | } |
99 | fprintf(stderr, wrongmsg, fingerprint); |
100 | fflush(stderr); |
101 | } |
102 | if (ret == 1) { /* key was absent */ |
103 | if (console_batch_mode) { |
104 | fprintf(stderr, absentmsg_batch, fingerprint); |
105 | cleanup_exit(1); |
106 | } |
107 | fprintf(stderr, absentmsg, fingerprint); |
108 | fflush(stderr); |
109 | } |
110 | |
111 | { |
112 | struct termios oldmode, newmode; |
113 | tcgetattr(0, &oldmode); |
114 | newmode = oldmode; |
115 | newmode.c_lflag |= ECHO | ISIG | ICANON; |
116 | tcsetattr(0, TCSANOW, &newmode); |
117 | line[0] = '\0'; |
118 | read(0, line, sizeof(line) - 1); |
119 | tcsetattr(0, TCSANOW, &oldmode); |
120 | } |
121 | |
122 | if (line[0] != '\0' && line[0] != '\r' && line[0] != '\n') { |
123 | if (line[0] == 'y' || line[0] == 'Y') |
124 | store_host_key(host, port, keytype, keystr); |
125 | } else { |
126 | fprintf(stderr, abandoned); |
127 | cleanup_exit(0); |
128 | } |
129 | } |
130 | |
131 | /* |
132 | * Ask whether the selected cipher is acceptable (since it was |
133 | * below the configured 'warn' threshold). |
134 | * cs: 0 = both ways, 1 = client->server, 2 = server->client |
135 | */ |
136 | void askcipher(void *frontend, char *ciphername, int cs) |
137 | { |
138 | static const char msg[] = |
139 | "The first %scipher supported by the server is\n" |
140 | "%s, which is below the configured warning threshold.\n" |
141 | "Continue with connection? (y/n) "; |
142 | static const char msg_batch[] = |
143 | "The first %scipher supported by the server is\n" |
144 | "%s, which is below the configured warning threshold.\n" |
145 | "Connection abandoned.\n"; |
146 | static const char abandoned[] = "Connection abandoned.\n"; |
147 | |
148 | char line[32]; |
149 | |
150 | if (console_batch_mode) { |
151 | fprintf(stderr, msg_batch, |
152 | (cs == 0) ? "" : |
153 | (cs == 1) ? "client-to-server " : "server-to-client ", |
154 | ciphername); |
155 | cleanup_exit(1); |
156 | } |
157 | |
158 | fprintf(stderr, msg, |
159 | (cs == 0) ? "" : |
160 | (cs == 1) ? "client-to-server " : "server-to-client ", |
161 | ciphername); |
162 | fflush(stderr); |
163 | |
164 | { |
165 | struct termios oldmode, newmode; |
166 | tcgetattr(0, &oldmode); |
167 | newmode = oldmode; |
168 | newmode.c_lflag |= ECHO | ISIG | ICANON; |
169 | tcsetattr(0, TCSANOW, &newmode); |
170 | line[0] = '\0'; |
171 | read(0, line, sizeof(line) - 1); |
172 | tcsetattr(0, TCSANOW, &oldmode); |
173 | } |
174 | |
175 | if (line[0] == 'y' || line[0] == 'Y') { |
176 | return; |
177 | } else { |
178 | fprintf(stderr, abandoned); |
179 | cleanup_exit(0); |
180 | } |
181 | } |
182 | |
183 | /* |
184 | * Ask whether to wipe a session log file before writing to it. |
185 | * Returns 2 for wipe, 1 for append, 0 for cancel (don't log). |
186 | */ |
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187 | int askappend(void *frontend, Filename filename) |
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188 | { |
189 | static const char msgtemplate[] = |
190 | "The session log file \"%.*s\" already exists.\n" |
191 | "You can overwrite it with a new session log,\n" |
192 | "append your session log to the end of it,\n" |
193 | "or disable session logging for this session.\n" |
194 | "Enter \"y\" to wipe the file, \"n\" to append to it,\n" |
195 | "or just press Return to disable logging.\n" |
196 | "Wipe the log file? (y/n, Return cancels logging) "; |
197 | |
198 | static const char msgtemplate_batch[] = |
199 | "The session log file \"%.*s\" already exists.\n" |
200 | "Logging will not be enabled.\n"; |
201 | |
202 | char line[32]; |
203 | |
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204 | if (console_batch_mode) { |
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205 | fprintf(stderr, msgtemplate_batch, FILENAME_MAX, filename.path); |
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206 | fflush(stderr); |
207 | return 0; |
208 | } |
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209 | fprintf(stderr, msgtemplate, FILENAME_MAX, filename.path); |
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210 | fflush(stderr); |
211 | |
212 | { |
213 | struct termios oldmode, newmode; |
214 | tcgetattr(0, &oldmode); |
215 | newmode = oldmode; |
216 | newmode.c_lflag |= ECHO | ISIG | ICANON; |
217 | tcsetattr(0, TCSANOW, &newmode); |
218 | line[0] = '\0'; |
219 | read(0, line, sizeof(line) - 1); |
220 | tcsetattr(0, TCSANOW, &oldmode); |
221 | } |
222 | |
223 | if (line[0] == 'y' || line[0] == 'Y') |
224 | return 2; |
225 | else if (line[0] == 'n' || line[0] == 'N') |
226 | return 1; |
227 | else |
228 | return 0; |
229 | } |
230 | |
231 | /* |
232 | * Warn about the obsolescent key file format. |
233 | * |
234 | * Uniquely among these functions, this one does _not_ expect a |
235 | * frontend handle. This means that if PuTTY is ported to a |
236 | * platform which requires frontend handles, this function will be |
237 | * an anomaly. Fortunately, the problem it addresses will not have |
238 | * been present on that platform, so it can plausibly be |
239 | * implemented as an empty function. |
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(void *frontend, char *string) |
258 | { |
a0e5ed33 |
259 | log_eventlog(logctx, string); |
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260 | } |
261 | |
262 | int console_get_line(const char *prompt, char *str, |
263 | int maxlen, int is_pw) |
264 | { |
265 | struct termios oldmode, newmode; |
266 | int i; |
267 | |
268 | if (console_batch_mode) { |
269 | if (maxlen > 0) |
270 | str[0] = '\0'; |
271 | } else { |
272 | tcgetattr(0, &oldmode); |
273 | newmode = oldmode; |
274 | newmode.c_lflag |= ISIG | ICANON; |
275 | if (is_pw) |
276 | newmode.c_lflag &= ~ECHO; |
277 | else |
278 | newmode.c_lflag |= ECHO; |
279 | tcsetattr(0, TCSANOW, &newmode); |
280 | |
281 | fputs(prompt, stdout); |
282 | fflush(stdout); |
283 | i = read(0, str, maxlen - 1); |
284 | |
285 | tcsetattr(0, TCSANOW, &oldmode); |
286 | |
287 | if (i > 0 && str[i-1] == '\n') |
288 | i--; |
289 | str[i] = '\0'; |
290 | |
291 | if (is_pw) |
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292 | fputs("\n", stdout); |
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293 | } |
294 | return 1; |
295 | } |
296 | |
297 | void frontend_keypress(void *handle) |
298 | { |
299 | /* |
300 | * This is nothing but a stub, in console code. |
301 | */ |
302 | return; |
303 | } |