git.distorted.org.uk Git - u/mdw/putty/blob - windows/wincons.c

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