Implement "putty -cleanup"

[originally from svn r626]

noise.c

@@ -107,6 +107,16 @@ void random_save_seed(void) {
     }
 }
 
+/*
+ * This function is called from `putty -cleanup'. It removes the
+ * random seed file.
+ */
+void random_destroy_seed(void) {
+    if (!seedpath[0])
+	get_seedpath();
+    remove(seedpath);
+}
+
 /*
  * This function is called every time the random pool needs
  * stirring, and will acquire the system time in all available

putty.h

@@ -2,6 +2,10 @@
 #define PUTTY_PUTTY_H
 
 #define PUTTY_REG_POS "Software\\SimonTatham\\PuTTY"
+#define PUTTY_REG_PARENT "Software\\SimonTatham"
+#define PUTTY_REG_PARENT_CHILD "PuTTY"
+#define PUTTY_REG_GPARENT "Software"
+#define PUTTY_REG_GPARENT_CHILD "SimonTatham"
 
 /*
  * Global variables. Most modules declare these `extern', but
@@ -254,6 +258,7 @@ void noise_get_heavy(void (*func) (void *, int));
 void noise_get_light(void (*func) (void *, int));
 void noise_ultralight(DWORD data);
 void random_save_seed(void);
+void random_destroy_seed(void);
 
 /*
  * Exports from windlg.c.
@@ -266,6 +271,7 @@ void showeventlog (HWND);
 void showabout (HWND);
 void verify_ssh_host_key(char *host, char *keystr);
 void get_sesslist(int allocate);
+void registry_cleanup(void);
 
 GLOBAL int nsessions;
 GLOBAL char **sessions;

windlg.c

@@ -1708,3 +1708,64 @@ void verify_ssh_host_key(char *host, char *keystr) {
 	RegCloseKey(rkey);
     }
 }
+
+/*
+ * Recursively delete a registry key and everything under it.
+ */
+static void registry_recursive_remove(HKEY key) {
+    DWORD i;
+    char name[MAX_PATH+1];
+    HKEY subkey;
+
+    i = 0;
+    while (RegEnumKey(key, i, name, sizeof(name)) == ERROR_SUCCESS) {
+        if (RegOpenKey(key, name, &subkey) == ERROR_SUCCESS) {
+            registry_recursive_remove(subkey);
+            RegCloseKey(subkey);
+        }
+        RegDeleteKey(key, name);
+    }
+}
+
+/*
+ * Destroy all registry information associated with PuTTY.
+ */
+void registry_cleanup(void) {
+    HKEY key;
+    int ret;
+    char name[MAX_PATH+1];
+
+    /*
+     * Open the main PuTTY registry key and remove everything in it.
+     */
+    if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_POS, &key) == ERROR_SUCCESS) {
+        registry_recursive_remove(key);
+        RegCloseKey(key);
+    }
+    /*
+     * Now open the parent key and remove the PuTTY main key. Once
+     * we've done that, see if the parent key has any other
+     * children.
+     */
+    if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_PARENT,
+                   &key) == ERROR_SUCCESS) {
+        RegDeleteKey(key, PUTTY_REG_PARENT_CHILD);
+        ret = RegEnumKey(key, 0, name, sizeof(name));
+        RegCloseKey(key);
+        /*
+         * If the parent key had no other children, we must delete
+         * it in its turn. That means opening the _grandparent_
+         * key.
+         */
+        if (ret != ERROR_SUCCESS) {
+            if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_GPARENT,
+                           &key) == ERROR_SUCCESS) {
+                RegDeleteKey(key, PUTTY_REG_GPARENT_CHILD);
+                RegCloseKey(key);
+            }
+        }
+    }
+    /*
+     * Now we're done.
+     */
+}

window.c

@@ -153,6 +153,33 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show) {
 		tolower(p[1]) == 'o' &&
 		tolower(p[2]) == 'g') {
                 logfile = "putty.log";
+	    } else if (q == p + 7 &&
+		tolower(p[0]) == 'c' &&
+		tolower(p[1]) == 'l' &&
+		tolower(p[2]) == 'e' &&
+		tolower(p[3]) == 'a' &&
+		tolower(p[4]) == 'n' &&
+		tolower(p[5]) == 'u' &&
+		tolower(p[6]) == 'p') {
+                /*
+                 * `putty -cleanup'. Remove all registry entries
+                 * associated with PuTTY, and also find and delete
+                 * the random seed file.
+                 */
+                if (MessageBox(NULL,
+                               "This procedure will remove ALL Registry\n"
+                               "entries associated with PuTTY, and will\n"
+                               "also remove the PuTTY random seed file.\n"
+                               "\n"
+                               "THIS PROCESS WILL DESTROY YOUR SAVED\n"
+                               "SESSIONS. Are you really sure you want\n"
+                               "to continue?",
+                               "PuTTY Warning",
+                               MB_YESNO | MB_ICONWARNING) == IDYES) {
+                    random_destroy_seed();
+                    registry_cleanup();
+                }
+                exit(0);
 	    }
 	    p = q + strspn(q, " \t");
 	}