Fix PRNG seeding to resist guessing

[empserver] / src / server / main.c

diff --git a/src/server/main.c b/src/server/main.c
index 267de1cdb37d75cb7e6173065d64c704ff3574c1..52c4c8cc3fb2eb72494b8cf155e96979aaf9683c 100644 (file)
--- a/src/server/main.c
+++ b/src/server/main.c
@@ -1,6 +1,6 @@
 /*
  *  Empire - A multi-player, client/server Internet based war game.
- *  Copyright (C) 1986-2011, Dave Pare, Jeff Bailey, Thomas Ruschak,
+ *  Copyright (C) 1986-2013, Dave Pare, Jeff Bailey, Thomas Ruschak,
  *                Ken Stevens, Steve McClure, Markus Armbruster
  *
  *  Empire is free software: you can redistribute it and/or modify
@@ -31,7 +31,7 @@
  *     Steve McClure, 1996, 1998
  *     Doug Hay, 1998
  *     Ron Koenderink, 2004-2009
- *     Markus Armbruster, 2005-2011
+ *     Markus Armbruster, 2005-2012
  */
 
 #include <config.h>
@@ -50,6 +50,7 @@
 #include "sys/socket.h"
 #endif
 
+#include "chance.h"
 #include "empio.h"
 #include "empthread.h"
 #include "file.h"
@@ -78,7 +79,7 @@ static void loc_NTInit(void);
  * Lock to synchronize player threads with update.
  * Update holds it exclusive, commands hold it shared.
  */
-empth_rwlock_t *play_lock;
+empth_rwlock_t *update_lock;
 /*
  * Lock to synchronize player threads with shutdown.
  * Shutdown holds it exclusive, player threads in state PS_PLAYING
@@ -142,7 +143,8 @@ main(int argc, char **argv)
     char *config_file = NULL;
     int force_bad_state = 0;
     int op, idx, sig;
-    unsigned seed = time(NULL);
+    unsigned seed = 0;
+    int seed_set = 0;
 
     oops_handler = ignore;
 
@@ -193,6 +195,7 @@ main(int argc, char **argv)
            break;
        case 'R':
            seed = strtoul(optarg, NULL, 10);
+           seed_set = 1;
            break;
        case 'v':
            printf("%s\n\n%s", version, legal);
@@ -253,6 +256,8 @@ main(int argc, char **argv)
        return install_service(program_name, service_name, config_file);
 #endif /* _WIN32 */
 
+    if (!seed_set)
+       seed = pick_seed();
     init_server(seed, force_bad_state);
 
 #if defined(_WIN32)
@@ -286,7 +291,6 @@ main(int argc, char **argv)
     }
 #endif /* !_WIN32 */
     start_server(flags);
-    journal_prng(seed);
 
     for (;;) {
        sig = empth_wait_for_signal();
@@ -350,7 +354,7 @@ crash_dump(void)
 static void
 init_server(unsigned seed, int force_bad_state)
 {
-    srandom(seed);
+    seed_prng(seed);
 #if defined(_WIN32)
     loc_NTInit();
 #endif
@@ -359,6 +363,9 @@ init_server(unsigned seed, int force_bad_state)
     io_init();
     init_nreport();
 
+    if (journal_startup() < 0)
+       exit(1);
+    journal_prng(seed);
     loginit("server");
 }
 
@@ -377,11 +384,9 @@ start_server(int flags)
 
     empth_init((void **)&player, flags);
 
-    if (journal_startup() < 0)
-       exit(1);
-
+    update_lock = empth_rwlock_create("Update");
     shutdown_lock = empth_rwlock_create("Shutdown");
-    if (!shutdown_lock)
+    if (!update_lock || !shutdown_lock)
        exit_nomem();
 
     market_init();