Squid Basic Authentication and Username Case
Check Basic authentication username normalization and helper lookup before changing valid passwords or account names.
Squid's Basic helper can receive a lowercase username even when the client supplied mixed case. Compare the backend account name with the identifier sent to the helper.
In Squid 5 through 7's documented Basic configuration, casesensitive controls preservation of uppercase letters. Its default off behavior converts the name to lowercase.
auth_param basic casesensitive onEnable it when the backend requires exact case, retaining the intended helper, credential file, and access policy.
Authorization must follow the same naming policy. An account preserved as Alex should not be assumed to match an ACL written for another case. Record the normalization setting and account identifier when diagnosing a mismatch, with passwords excluded from logs.