Add a 'from_server' flag in prompts_t.

This goes with the existing 'to_server' flag (indicating whether the
values typed by the user are going to be sent over the wire or remain
local), to indicate whether the _text of the prompts_ has come over
the wire or is originated locally.

Like to_server, nothing yet uses this. It's a hedge against the
possibility of maybe having an option for all the auth prompts to work
via GUI dialog boxes.

cmdgen.c

@@ -753,6 +753,7 @@ int main(int argc, char **argv)
 		prompts_t *p = new_prompts();
 		int ret;
 		p->to_server = false;
+		p->from_server = false;
 		p->name = dupstr("SSH key passphrase");
 		add_prompt(p, dupstr("Enter passphrase to load key: "), false);
 		ret = console_get_userpass_input(p);
@@ -889,6 +890,7 @@ int main(int argc, char **argv)
 	int ret;
 
 	p->to_server = false;
+	p->from_server = false;
 	p->name = dupstr("New SSH key passphrase");
 	add_prompt(p, dupstr("Enter passphrase to save key: "), false);
 	add_prompt(p, dupstr("Re-enter passphrase to verify: "), false);

putty.h

@@ -659,6 +659,15 @@ typedef struct {
      * sufficient).
      */
     bool to_server;
+
+    /*
+     * Indicates whether the prompts originated _at_ the server, so
+     * that the front end can display some kind of trust sigil that
+     * distinguishes (say) a legit private-key passphrase prompt from
+     * a fake one sent by a malicious server.
+     */
+    bool from_server;
+
     char *name;		/* Short description, perhaps for dialog box title */
     bool name_reqd;     /* Display of `name' required or optional? */
     char *instruction;	/* Long description, maybe with embedded newlines */

rlogin.c

@@ -228,6 +228,7 @@ static const char *rlogin_init(Seat *seat, Backend **backend_handle,
 
         rlogin->prompt = new_prompts();
         rlogin->prompt->to_server = true;
+        rlogin->prompt->from_server = false;
         rlogin->prompt->name = dupstr("Rlogin login name");
         add_prompt(rlogin->prompt, dupstr("rlogin username: "), true); 
         ret = seat_get_userpass_input(rlogin->seat, rlogin->prompt, NULL);

ssh1login.c

@@ -383,6 +383,7 @@ static void ssh1_login_process_queue(PacketProtocolLayer *ppl)
     if ((s->username = get_remote_username(s->conf)) == NULL) {
         s->cur_prompt = new_prompts();
         s->cur_prompt->to_server = true;
+        s->cur_prompt->from_server = false;
         s->cur_prompt->name = dupstr("SSH login name");
         add_prompt(s->cur_prompt, dupstr("login as: "), true);
         s->userpass_ret = seat_get_userpass_input(
@@ -641,6 +642,7 @@ static void ssh1_login_process_queue(PacketProtocolLayer *ppl)
                 } else {
                     s->cur_prompt = new_prompts(s->ppl.seat);
                     s->cur_prompt->to_server = false;
+                    s->cur_prompt->from_server = false;
                     s->cur_prompt->name = dupstr("SSH key passphrase");
                     add_prompt(s->cur_prompt,
                                dupprintf("Passphrase for key \"%s\": ",
@@ -805,6 +807,7 @@ static void ssh1_login_process_queue(PacketProtocolLayer *ppl)
                 }
                 ppl_logevent("Received TIS challenge");
                 s->cur_prompt->to_server = true;
+                s->cur_prompt->from_server = true;
                 s->cur_prompt->name = dupstr("SSH TIS authentication");
                 /* Prompt heuristic comes from OpenSSH */
                 if (!memchr(challenge.ptr, '\n', challenge.len)) {
@@ -853,6 +856,7 @@ static void ssh1_login_process_queue(PacketProtocolLayer *ppl)
                 }
                 ppl_logevent("Received CryptoCard challenge");
                 s->cur_prompt->to_server = true;
+                s->cur_prompt->from_server = true;
                 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
                 s->cur_prompt->name_reqd = false;
                 /* Prompt heuristic comes from OpenSSH */
@@ -885,6 +889,7 @@ static void ssh1_login_process_queue(PacketProtocolLayer *ppl)
                 return;
             }
             s->cur_prompt->to_server = true;
+            s->cur_prompt->from_server = false;
             s->cur_prompt->name = dupstr("SSH password");
             add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
                                                 s->username, s->savedhost),

ssh2userauth.c

@@ -385,6 +385,7 @@ static void ssh2_userauth_process_queue(PacketProtocolLayer *ppl)
         } else if ((s->username = s->default_username) == NULL) {
             s->cur_prompt = new_prompts();
             s->cur_prompt->to_server = true;
+            s->cur_prompt->from_server = false;
             s->cur_prompt->name = dupstr("SSH login name");
             add_prompt(s->cur_prompt, dupstr("login as: "), true); 
             s->userpass_ret = seat_get_userpass_input(
@@ -822,6 +823,7 @@ static void ssh2_userauth_process_queue(PacketProtocolLayer *ppl)
                          */
                         s->cur_prompt = new_prompts();
                         s->cur_prompt->to_server = false;
+                        s->cur_prompt->from_server = false;
                         s->cur_prompt->name = dupstr("SSH key passphrase");
                         add_prompt(s->cur_prompt,
                                    dupprintf("Passphrase for key \"%s\": ",
@@ -1201,6 +1203,7 @@ static void ssh2_userauth_process_queue(PacketProtocolLayer *ppl)
                     get_string(pktin); /* skip language tag */
                     s->cur_prompt = new_prompts();
                     s->cur_prompt->to_server = true;
+                    s->cur_prompt->from_server = true;
 
                     /*
                      * Get any prompt(s) from the packet.
@@ -1326,6 +1329,7 @@ static void ssh2_userauth_process_queue(PacketProtocolLayer *ppl)
 
                 s->cur_prompt = new_prompts();
                 s->cur_prompt->to_server = true;
+                s->cur_prompt->from_server = false;
                 s->cur_prompt->name = dupstr("SSH password");
                 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
                                                     s->username, s->hostname),
@@ -1420,6 +1424,7 @@ static void ssh2_userauth_process_queue(PacketProtocolLayer *ppl)
 
                     s->cur_prompt = new_prompts();
                     s->cur_prompt->to_server = true;
+                    s->cur_prompt->from_server = false;
                     s->cur_prompt->name = dupstr("New SSH password");
                     s->cur_prompt->instruction = mkstr(prompt);
                     s->cur_prompt->instr_reqd = true;

unix/uxpgnt.c

@@ -328,6 +328,7 @@ static char *askpass_tty(const char *prompt)
     int ret;
     prompts_t *p = new_prompts();
     p->to_server = false;
+    p->from_server = false;
     p->name = dupstr("Pageant passphrase prompt");
     add_prompt(p, dupcat(prompt, ": ", (const char *)NULL), false);
     ret = console_get_userpass_input(p);