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

   1 /*
   2  * wincons.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 set_busy_status(void *frontend, int status)
  37 {
  38 }
  39
  40 void notify_remote_exit(void *frontend)
  41 {
  42 }
  43
  44 void timer_change_notify(long next)
  45 {
  46 }
  47
  48 int verify_ssh_host_key(void *frontend, char *host, int port, char *keytype,
  49                         char *keystr, char *fingerprint,
  50                         void (*callback)(void *ctx, int result), void *ctx)
  51 {
  52     int ret;
  53     HANDLE hin;
  54     DWORD savemode, i;
  55
  56     static const char absentmsg_batch[] =
  57         "The server's host key is not cached in the registry. You\n"
  58         "have no guarantee that the server is the computer you\n"
  59         "think it is.\n"
  60         "The server's %s key fingerprint is:\n"
  61         "%s\n"
  62         "Connection abandoned.\n";
  63     static const char absentmsg[] =
  64         "The server's host key is not cached in the registry. You\n"
  65         "have no guarantee that the server is the computer you\n"
  66         "think it is.\n"
  67         "The server's %s key fingerprint is:\n"
  68         "%s\n"
  69         "If you trust this host, enter \"y\" to add the key to\n"
  70         "PuTTY's cache and carry on connecting.\n"
  71         "If you want to carry on connecting just once, without\n"
  72         "adding the key to the cache, enter \"n\".\n"
  73         "If you do not trust this host, press Return to abandon the\n"
  74         "connection.\n"
  75         "Store key in cache? (y/n) ";
  76
  77     static const char wrongmsg_batch[] =
  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 %s key fingerprint is:\n"
  85         "%s\n"
  86         "Connection abandoned.\n";
  87     static const char wrongmsg[] =
  88         "WARNING - POTENTIAL SECURITY BREACH!\n"
  89         "The server's host key does not match the one PuTTY has\n"
  90         "cached in the registry. This means that either the\n"
  91         "server administrator has changed the host key, or you\n"
  92         "have actually connected to another computer pretending\n"
  93         "to be the server.\n"
  94         "The new %s key fingerprint is:\n"
  95         "%s\n"
  96         "If you were expecting this change and trust the new key,\n"
  97         "enter \"y\" to update PuTTY's cache and continue connecting.\n"
  98         "If you want to carry on connecting but without updating\n"
  99         "the cache, enter \"n\".\n"
 100         "If you want to abandon the connection completely, press\n"
 101         "Return to cancel. Pressing Return is the ONLY guaranteed\n"
 102         "safe choice.\n"
 103         "Update cached key? (y/n, Return cancels connection) ";
 104
 105     static const char abandoned[] = "Connection abandoned.\n";
 106
 107     char line[32];
 108
 109     /*
 110      * Verify the key against the registry.
 111      */
 112     ret = verify_host_key(host, port, keytype, keystr);
 113
 114     if (ret == 0)                      /* success - key matched OK */
 115         return 1;
 116
 117     if (ret == 2) {                    /* key was different */
 118         if (console_batch_mode) {
 119             fprintf(stderr, wrongmsg_batch, keytype, fingerprint);
 120             return 0;
 121         }
 122         fprintf(stderr, wrongmsg, keytype, fingerprint);
 123         fflush(stderr);
 124     }
 125     if (ret == 1) {                    /* key was absent */
 126         if (console_batch_mode) {
 127             fprintf(stderr, absentmsg_batch, keytype, fingerprint);
 128             return 0;
 129         }
 130         fprintf(stderr, absentmsg, keytype, fingerprint);
 131         fflush(stderr);
 132     }
 133
 134     hin = GetStdHandle(STD_INPUT_HANDLE);
 135     GetConsoleMode(hin, &savemode);
 136     SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
 137                          ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
 138     ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
 139     SetConsoleMode(hin, savemode);
 140
 141     if (line[0] != '\0' && line[0] != '\r' && line[0] != '\n') {
 142         if (line[0] == 'y' || line[0] == 'Y')
 143             store_host_key(host, port, keytype, keystr);
 144         return 1;
 145     } else {
 146         fprintf(stderr, abandoned);
 147         return 0;
 148     }
 149 }
 150
 151 void update_specials_menu(void *frontend)
 152 {
 153 }
 154
 155 /*
 156  * Ask whether the selected algorithm is acceptable (since it was
 157  * below the configured 'warn' threshold).
 158  */
 159 int askalg(void *frontend, const char *algtype, const char *algname,
 160            void (*callback)(void *ctx, int result), void *ctx)
 161 {
 162     HANDLE hin;
 163     DWORD savemode, i;
 164
 165     static const char msg[] =
 166         "The first %s supported by the server is\n"
 167         "%s, which is below the configured warning threshold.\n"
 168         "Continue with connection? (y/n) ";
 169     static const char msg_batch[] =
 170         "The first %s supported by the server is\n"
 171         "%s, which is below the configured warning threshold.\n"
 172         "Connection abandoned.\n";
 173     static const char abandoned[] = "Connection abandoned.\n";
 174
 175     char line[32];
 176
 177     if (console_batch_mode) {
 178         fprintf(stderr, msg_batch, algtype, algname);
 179         return 0;
 180     }
 181
 182     fprintf(stderr, msg, algtype, algname);
 183     fflush(stderr);
 184
 185     hin = GetStdHandle(STD_INPUT_HANDLE);
 186     GetConsoleMode(hin, &savemode);
 187     SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
 188                          ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
 189     ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
 190     SetConsoleMode(hin, savemode);
 191
 192     if (line[0] == 'y' || line[0] == 'Y') {
 193         return 1;
 194     } else {
 195         fprintf(stderr, abandoned);
 196         return 0;
 197     }
 198 }
 199
 200 /*
 201  * Ask whether to wipe a session log file before writing to it.
 202  * Returns 2 for wipe, 1 for append, 0 for cancel (don't log).
 203  */
 204 int askappend(void *frontend, Filename filename,
 205               void (*callback)(void *ctx, int result), void *ctx)
 206 {
 207     HANDLE hin;
 208     DWORD savemode, i;
 209
 210     static const char msgtemplate[] =
 211         "The session log file \"%.*s\" already exists.\n"
 212         "You can overwrite it with a new session log,\n"
 213         "append your session log to the end of it,\n"
 214         "or disable session logging for this session.\n"
 215         "Enter \"y\" to wipe the file, \"n\" to append to it,\n"
 216         "or just press Return to disable logging.\n"
 217         "Wipe the log file? (y/n, Return cancels logging) ";
 218
 219     static const char msgtemplate_batch[] =
 220         "The session log file \"%.*s\" already exists.\n"
 221         "Logging will not be enabled.\n";
 222
 223     char line[32];
 224
 225     if (console_batch_mode) {
 226         fprintf(stderr, msgtemplate_batch, FILENAME_MAX, filename.path);
 227         fflush(stderr);
 228         return 0;
 229     }
 230     fprintf(stderr, msgtemplate, FILENAME_MAX, filename.path);
 231     fflush(stderr);
 232
 233     hin = GetStdHandle(STD_INPUT_HANDLE);
 234     GetConsoleMode(hin, &savemode);
 235     SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
 236                          ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
 237     ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
 238     SetConsoleMode(hin, savemode);
 239
 240     if (line[0] == 'y' || line[0] == 'Y')
 241         return 2;
 242     else if (line[0] == 'n' || line[0] == 'N')
 243         return 1;
 244     else
 245         return 0;
 246 }
 247
 248 /*
 249  * Warn about the obsolescent key file format.
 250  *
 251  * Uniquely among these functions, this one does _not_ expect a
 252  * frontend handle. This means that if PuTTY is ported to a
 253  * platform which requires frontend handles, this function will be
 254  * an anomaly. Fortunately, the problem it addresses will not have
 255  * been present on that platform, so it can plausibly be
 256  * implemented as an empty function.
 257  */
 258 void old_keyfile_warning(void)
 259 {
 260     static const char message[] =
 261         "You are loading an SSH-2 private key which has an\n"
 262         "old version of the file format. This means your key\n"
 263         "file is not fully tamperproof. Future versions of\n"
 264         "PuTTY may stop supporting this private key format,\n"
 265         "so we recommend you convert your key to the new\n"
 266         "format.\n"
 267         "\n"
 268         "Once the key is loaded into PuTTYgen, you can perform\n"
 269         "this conversion simply by saving it again.\n";
 270
 271     fputs(message, stderr);
 272 }
 273
 274 /*
 275  * Display the fingerprints of the PGP Master Keys to the user.
 276  */
 277 void pgp_fingerprints(void)
 278 {
 279     fputs("These are the fingerprints of the PuTTY PGP Master Keys. They can\n"
 280           "be used to establish a trust path from this executable to another\n"
 281           "one. See the manual for more information.\n"
 282           "(Note: these fingerprints have nothing to do with SSH!)\n"
 283           "\n"
 284           "PuTTY Master Key (RSA), 1024-bit:\n"
 285           "  " PGP_RSA_MASTER_KEY_FP "\n"
 286           "PuTTY Master Key (DSA), 1024-bit:\n"
 287           "  " PGP_DSA_MASTER_KEY_FP "\n", stdout);
 288 }
 289
 290 void console_provide_logctx(void *logctx)
 291 {
 292     console_logctx = logctx;
 293 }
 294
 295 void logevent(void *frontend, const char *string)
 296 {
 297     if (console_logctx)
 298         log_eventlog(console_logctx, string);
 299 }
 300
 301 static void console_data_untrusted(HANDLE hout, const char *data, int len)
 302 {
 303     DWORD dummy;
 304     /* FIXME: control-character filtering */
 305     WriteFile(hout, data, len, &dummy, NULL);
 306 }
 307
 308 int console_get_userpass_input(prompts_t *p, unsigned char *in, int inlen)
 309 {
 310     HANDLE hin, hout;
 311     size_t curr_prompt;
 312
 313     /*
 314      * Zero all the results, in case we abort half-way through.
 315      */
 316     {
 317         int i;
 318         for (i = 0; i < p->n_prompts; i++)
 319             memset(p->prompts[i]->result, 0, p->prompts[i]->result_len);
 320     }
 321
 322     if (console_batch_mode)
 323         return 0;
 324
 325     hin = GetStdHandle(STD_INPUT_HANDLE);
 326     hout = GetStdHandle(STD_OUTPUT_HANDLE);
 327     if (hin == INVALID_HANDLE_VALUE || hout == INVALID_HANDLE_VALUE) {
 328         fprintf(stderr, "Cannot get standard input/output handles\n");
 329         cleanup_exit(1);
 330     }
 331
 332     /*
 333      * Preamble.
 334      */
 335     /* We only print the `name' caption if we have to... */
 336     if (p->name_reqd && p->name) {
 337         size_t l = strlen(p->name);
 338         console_data_untrusted(hout, p->name, l);
 339         if (p->name[l-1] != '\n')
 340             console_data_untrusted(hout, "\n", 1);
 341     }
 342     /* ...but we always print any `instruction'. */
 343     if (p->instruction) {
 344         size_t l = strlen(p->instruction);
 345         console_data_untrusted(hout, p->instruction, l);
 346         if (p->instruction[l-1] != '\n')
 347             console_data_untrusted(hout, "\n", 1);
 348     }
 349
 350     for (curr_prompt = 0; curr_prompt < p->n_prompts; curr_prompt++) {
 351
 352         DWORD savemode, newmode, i = 0;
 353         prompt_t *pr = p->prompts[curr_prompt];
 354         BOOL r;
 355
 356         GetConsoleMode(hin, &savemode);
 357         newmode = savemode | ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT;
 358         if (!pr->echo)
 359             newmode &= ~ENABLE_ECHO_INPUT;
 360         else
 361             newmode |= ENABLE_ECHO_INPUT;
 362         SetConsoleMode(hin, newmode);
 363
 364         console_data_untrusted(hout, pr->prompt, strlen(pr->prompt));
 365
 366         r = ReadFile(hin, pr->result, pr->result_len - 1, &i, NULL);
 367
 368         SetConsoleMode(hin, savemode);
 369
 370         if ((int) i > pr->result_len)
 371             i = pr->result_len - 1;
 372         else
 373             i = i - 2;
 374         pr->result[i] = '\0';
 375
 376         if (!pr->echo) {
 377             DWORD dummy;
 378             WriteFile(hout, "\r\n", 2, &dummy, NULL);
 379         }
 380
 381     }
 382
 383     return 1; /* success */
 384
 385 }
 386
 387 void frontend_keypress(void *handle)
 388 {
 389     /*
 390      * This is nothing but a stub, in console code.
 391      */
 392     return;
 393 }