title: Can't set md5 password in HSQLDB: routine signature not found
body: <p>Documentation on MD5 in HSQLDB is somewhat scarce, but I have followed these instructions to in order to enable md5-ing my passwords:</p>
  
  <pre><code>CREATE FUNCTION md5(VARBINARY(128))
  RETURNS VARBINARY(226)
  LANGUAGE JAVA
  DETERMINISTIC
  NO SQL
  EXTERNAL NAME 'CLASSPATH:org.hsqldb.lib.MD5.digest'
  </code></pre>
  
  <p>Now when I try to update my password:</p>
  
  <pre><code>UPDATE worker SET password = md5('pass123') WHERE wid=1
  </code></pre>
  
  <p>I get the following error:</p>
  
  <pre><code>java.sql.SQLException: routine signature not found for: PUBLIC.MD5(CHARACTER)
  </code></pre>
  
  <p>I'm not that well acquainted with sql, so I'm not sure where I'm making a mistake.</p>