Eu decidi começar com um servidor limpo. Os erros que eu estava encontrando foram realmente devido ao navegador ainda não ter o certificado de cliente; e, como tal, estava exibindo mensagens de erro obscuras.
<VirtualHost _default_:443>
ServerAdmin [email protected]
ServerName secure.somedomain.com
SSLEngine On
SSLCertificateFile /var/websites/ssl/certificate.crt
SSLCertificateKeyFile /var/websites/ssl/certificate.key
SSLCertificateChainFile /var/websites/ssl/cachain.pem
DocumentRoot /var/websites/www
<Directory />
Options FollowSymLinks
AllowOverride None
</Directory>
<Directory /var/websites/www>
Options Indexes FollowSymLinks MultiViews
AllowOverride None
Order allow,deny
allow from all
SetHandler mono
DirectoryIndex index.html index.aspx default.aspx
SSLRequireSSL
SSLCACertificateFile /etc/apache2/ownca.pem
SSLVerifyClient require
SSLVerifyDepth 1
SSLOptions +StrictRequire +StdEnvVars +ExportCertData
</Directory>
LogLevel warn
ErrorLog /var/websites/logs/error_443.log
CustomLog /var/websites/logs/access_443.log combined
ServerSignature On