auth_http_pass_client_cert
The `auth_http_pass_client_cert` directive configures whether to pass the client certificate to the authentication HTTP server.
Description
The auth_http_pass_client_cert directive is part of the NGINX Mail Core module and controls the behavior of client certificate forwarding during HTTP authentication processes. When set to on, NGINX forwards the client certificate to an external HTTP authentication server, which can then inspect or validate it as needed. This is particularly useful in setups where client certificates are part of an authentication mechanism, allowing for checks against a centralized server.
This directive can take two values: on and off. By default, the directive is set to off, meaning that the client certificate will not be forwarded. If the feature is required, operators must explicitly declare it in their NGINX mail configuration. When on, the relevant client SSL information is passed along, which is essential for the proper validation of user identification via certificates.
In operational use, proper testing should be conducted to ensure that the configuration works as intended, especially in environments where client certificates are required for accessing certain resources. Misconfiguring this directive could lead to authentication failures or security vulnerabilities if certificates are incorrectly processed or made available when they should not be.
Config Example
mail {
auth_http_pass_client_cert on;
# additional configuration...
}Ensure that the external HTTP authentication server is correctly set up to handle client certificates being sent.
Misunderstanding the effect of setting this directive to on, as it can expose client certificates if not handled properly by the HTTP server.