# HG changeset patch
# User Markus Bröker <mbroeker@largo.dyndns.tv>
# Date 1267144966 -3600
# Node ID 59b09b0aeb96ef6bcff97213489d3c9a616d6c32
# Parent  34094173351c48aab6e39a6b0a0d3b42c13a89ce
safe_strncpy replaces the insecure strncpy function

strncpy copies up to n bytes and does not terminate it, except the
null byte is in the first n bytes...

committer: Markus Bröker <mbroeker@largo.homelinux.org>

diff --git a/include/compat.h b/include/compat.h
--- a/include/compat.h
+++ b/include/compat.h
@@ -8,4 +8,5 @@
 #define COMPAT_H
 
 char *compat_strdup (const char *);
+char *safe_strncpy (char *dest, const char *src, size_t size);
 #endif
diff --git a/src/compat.c b/src/compat.c
--- a/src/compat.c
+++ b/src/compat.c
@@ -19,3 +19,18 @@
 
     return buf;
 }
+
+char *safe_strncpy (char *dest, const char *src, size_t size)
+{
+    size_t i;
+
+    for (i = 0; i < size - 1; i++) {
+        if (src[i] == '\0')
+            break;
+        dest[i] = src[i];
+    }
+
+    dest[i] = '\0';
+
+    return dest;
+}
diff --git a/src/irc.c b/src/irc.c
--- a/src/irc.c
+++ b/src/irc.c
@@ -259,7 +259,7 @@
                         *ptr = '\0';
 
                     message->channel = strtok (message->line, " ");
-                    strncpy (message->current_channel, message->channel, sizeof (message->current_channel));
+                    safe_strncpy (message->current_channel, message->channel, sizeof (message->current_channel));
                     message->line = strtok (NULL, "\r\n");
                     message->line++;
                     printf ("%10s %s %s :%s\n", "READ", message->command, message->channel, message->line);
diff --git a/src/main.c b/src/main.c
--- a/src/main.c
+++ b/src/main.c
@@ -16,6 +16,8 @@
 #include <config.h>
 #include "common.h"
 
+#include <compat.h>
+
 #ifndef CONFIG_FILE
 #define CONFIG_FILE "/var/lib/mcbot/.mcbotrc"
 #endif
@@ -86,7 +88,7 @@
 
     if (uc.channel) {
         fprintf (message.stream, "JOIN :%s\r\n", uc.channel);
-        strncpy (message.current_channel, uc.channel, 40);
+        safe_strncpy (message.current_channel, uc.channel, sizeof (message.current_channel));
         if (uc.topic)
             fprintf (message.stream, "TOPIC %s :%s\r\n", uc.channel, uc.topic);
     }