WSSecurityEngine: No password callback supplied

Issue

I have build an example webservice with WS-Security to authenticate using usernameToken. The example works fine when I'm running this from a WAR, but when I try to run it from within an EJB EAR I get an error similar to this:

Caused by: org.apache.ws.security.WSSecurityException: General security error (WSSecurityEngine: No password callback supplied)
        at org.apache.ws.security.validate.UsernameTokenValidator.verifyDigestPassword(UsernameTokenValidator.java:155) [wss4j-1.6.7-redhat-1.jar:1.6.7-redhat-1]
        at org.apache.ws.security.validate.UsernameTokenValidator.verifyPlaintextPassword(UsernameTokenValidator.java:142) [wss4j-1.6.7-redhat-1.jar:1.6.7-redhat-1]
        at org.apache.ws.security.validate.UsernameTokenValidator.validate(UsernameTokenValidator.java:100) [wss4j-1.6.7-redhat-1.jar:1.6.7-redhat-1]
        at org.apache.ws.security.processor.UsernameTokenProcessor.handleUsernameToken(UsernameTokenProcessor.java:152) [wss4j-1.6.7-redhat-1.jar:1.6.7-redhat-1]
        at org.apache.ws.security.processor.UsernameTokenProcessor.handleToken(UsernameTokenProcessor.java:66) [wss4j-1.6.7-redhat-1.jar:1.6.7-redhat-1]
        at org.apache.cxf.ws.security.wss4j.UsernameTokenInterceptor.getPrincipal(UsernameTokenInterceptor.java:193) [cxf-rt-ws-security-2.4.9-redhat-3.jar:2.4.9-redhat-3]
        at org.apache.cxf.ws.security.wss4j.UsernameTokenInterceptor.processUsernameToken(UsernameTokenInterceptor.java:134) [cxf-rt-ws-security-2.4.9-redhat-3.jar:2.4.9-redhat-3]
        ... 29 more