- int ret;
-
- static const char absentmsg[] =
- "The server's host key is not cached. You have no guarantee\n"
- "that the server is the computer you 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[] =
- "WARNING - POTENTIAL SECURITY BREACH!\n"
- "The server's host key does not match the one PuTTY has\n"
- "cached. This means that either the server administrator\n"
- "has changed the host key, or you have actually connected\n"
- "to another computer pretending 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.
- */
- ret = verify_host_key(host, port, keytype, keystr);
-
- if (ret == 0) /* success - key matched OK */
- return;
-
- if (ret == 2) { /* key was different */
- fprintf(stderr, wrongmsg, fingerprint);
- fflush(stderr);
- }
- if (ret == 1) { /* key was absent */
- fprintf(stderr, absentmsg, fingerprint);
- fflush(stderr);
- }
-
- {
- struct termios oldmode, newmode;
- tcgetattr(0, &oldmode);
- newmode = oldmode;
- newmode.c_lflag |= ECHO | ISIG | ICANON;
- tcsetattr(0, TCSANOW, &newmode);
- line[0] = '\0';
- read(0, line, sizeof(line) - 1);
- tcsetattr(0, TCSANOW, &oldmode);
- }
-
- 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);
- }