in src/main/java/org/apache/sling/auth/form/impl/FormAuthenticationHandler.java [525:537]
private String getCookieAuthData(final Credentials credentials) {
if (credentials instanceof SimpleCredentials) {
Object data = ((SimpleCredentials) credentials).getAttribute(attrCookieAuthData);
if (data instanceof String) {
return (String) data;
}
} else if (credentials instanceof FormCredentials) {
return ((FormCredentials) credentials).getAuthData();
}
// no SimpleCredentials or no valid attribute
return null;
}