We have an existing Confluence instance and want to change to authenticate through JIRA/LDAP

[Kevin Cassidy]

We originally installed JIRA with 50 user licenses and later purchased Confluence with only 25 licenses.  We set up Confluence to use JIRA's authentication but the mis match in license counts caused issues.  We now have 100 user licenses for each tool and want to set up Confluence to use JIRA authentication since our users are normally in JIRA and pop over to Confuence.  The multiple log ins between the tools is a pain.  We have both systems set up to use LDAP for user authentication and the permissions are managed through each tool locally. 

[Bruno Vincent]

As far as I understand both your Jira and Confluence instances now use LDAP authentication but you don't want to re-enter your LDAP credentials when browsing from one application to another. So what you need is SSO. Atlassian Crowd is the recommended tool to get SSO on your Atlassian stack. Please also allow me to suggest you to take a look at the IWAAC plugin thanks to which you won't even have to enter your LDAP username/password at all. (Disclaimer: I work for the vendor of this plugin)