From 4348ad76758ba2fd547d7a9ae046833bfe33e669 Mon Sep 17 00:00:00 2001
From: Richard Hansen <rhansen@rhansen.org>
Date: Tue, 16 Jun 2020 13:51:21 -0400
Subject: [PATCH] Truncate freedns passwords longer than 16 chars

Fixes #176
---
 ChangeLog.md | 4 ++++
 ddclient     | 6 +++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 68abea5..4dff5f3 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -9,6 +9,10 @@ repository history](https://github.com/ddclient/ddclient/commits/master).
 
   * Added support for OVH DynHost.
 
+### Bug fixes
+
+  * Fixed freedns.afraid.org for passwords longer than 16 characters.
+
 ### Compatibility and dependency changes
 
   * Perl v5.10.1 or later is now required.
diff --git a/ddclient b/ddclient
index f3b16f5..79e3ee3 100755
--- a/ddclient
+++ b/ddclient
@@ -3844,7 +3844,11 @@ sub nic_freedns_update {
 
     ## First get the list of updatable hosts
     my $url;
-    $url = "http://$config{$_[0]}{'server'}/api/?action=getdyndns&sha=" . &sha1_hex("$config{$_[0]}{'login'}|$config{$_[0]}{'password'}");
+    # https://freedns.afraid.org/api/ says, "Password is maximum length of 16 characters."
+    # Experimentation has shown that this means that longer passwords must be truncated.
+    my $truncated_password = substr($config{$_[0]}{'password'}, 0, 16);
+    my $hashed_creds = sha1_hex("$config{$_[0]}{'login'}|$truncated_password");
+    $url = "http://$config{$_[0]}{'server'}/api/?action=getdyndns&sha=" . $hashed_creds;
     my $reply = geturl(opt('proxy'), $url);
     if (!defined($reply) || !$reply || !header_ok($_[0], $reply)) {
         failed("updating %s: Could not connect to %s for site list.", $_[0], $url);