I'm sure it is already documented, how to assign certificates to a dedicated username. But I so far didn't find it.
To my knowledge a TLS certificate will contain a username (a NAI) in TLS-Client-Cert-Common-Name. You can always check that if the TLS name does not match the username specified, you reject the request? :-) Stefan Paetow Moonshot Industry & Research Liaison Coordinator t: +44 (0)1235 822 125 gpg: 0x3FCE5142 xmpp: stefanp@jabber.dev.ja.net skype: stefan.paetow.janet jisc.ac.uk Jisc is a registered charity (number 1149740) and a company limited by guarantee which is registered in England under Company No. 5747339, VAT No. GB 197 0632 86. Jisc¹s registered office is: One Castlepark, Tower Hill, Bristol, BS2 0JA. T 0203 697 5800.