You've spent hours getting your encryption keys in order. You've successfully got a granting key and a crypt key from your pubcookie server. Your Apache ssl.conf is finely honed and your external SSL tests are flawless.
Yet your users can't log in. They're not being redirected to the central login server. Instead, they see messages like
Authorization Required
This server could not verify that you are authorized to access the document requested. Either you supplied the wrong credentials (e.g., bad password), or your browser doesn't understand how to supply the credentials required.
And in your ssl_access.log you're just seeing 401 after 401.
In your ssl_error.log you see
access to [file] failed, reason: verification of user id '<null>' not configured
You can curse. You can jump up and down. You can throw things on the floor. But what's really going to help you is this tidbit of knowledge:
Something is overriding your PubcookieAuthTypeNames directive.
What is happening is that when your .htaccess file is read, the AuthType directive there doesn't match anything in your mod_pubcookie.conf file because your directive got overridden by another line somewhere, probably something like
PubcookieAuthTypeNames WebISO
Fix that error, restart Apache, and go have a nice lie-down somewhere.