I would appreciate if there is anybody who can advise me if the following FTP configuration is possible. I need range of read-only users that follow this pattern:


e.g., _012345678901234 that will use same password without creating all possible combinations. The use case is the following - we provisioning devices and they are using FTP to download new version of firmware. In the log I can see both username and password used to download files. The main goal is to have device serial number in the log.

I did not find a way to specify wildcard for username. Currently we have anonymous access only, but it's obviously not good enough.

1 Answer 1


In ProFTPD there is no straightforward way to specify a wildcard for a username. However you can use mod_sql to authenticate your users and customize queries used to get user info.

Example of custom queries taken from ProFTPD docs:

SQLAuthenticate users groups usersetfast
SQLUserInfo custom:/get-user-by-name/get-user-by-id/get-user-names/get-all-users
SQLNamedQuery get-user-by-name SELECT "userid, passwd, uid, gid, homedir, shell FROM users WHERE userid = '%U'"
SQLNamedQuery get-user-by-id SELECT "userid, passwd, uid, gid, homedir, shell FROM users WHERE uid = %{0}"
SQLNamedQuery get-user-names SELECT "userid FROM users"
SQLNamedQuery get-all-users SELECT "userid, passwd, uid, gid, homedir, shell FROM users" 

In your case get-user-by-name query could look something like:

SQLNamedQuery get-user-by-name SELECT "'%U', passwd, uid, gid, homedir, shell FROM users WHERE userid = SUBSTRING_INDEX('%U', '_', 1) AND SUBSTRING_INDEX('%U', '_', -1) RLIKE '_[0-9]{15}'"

Please note that this is not a tested solution. Just an idea of one possible way how this could be achieved.

  • In theory with some DNS providers I should be able to define wildcard A or CNAME record to resolve *.ftp.company.com to ftp.company.com or ip address. The question is: Can I configure logging in proftpd somehow to write host name used to access ftp service to the log? I know there would be a problem as I cannot have wildcard host name in /etc/hosts.
    – ruruskyi
    Jul 22, 2014 at 17:21
  • ProFTPD and FTP for that matter is not aware of hostnames. Read this.
    – grekasius
    Jul 22, 2014 at 17:35
  • Did you consider using HTTP instead?
    – grekasius
    Jul 22, 2014 at 17:37
  • Unfortunately HTTP isn't a case, FTP is already in place on embedded devices. Is it possible to define 100,000 aliases for the same ftp user in config file, e.g., _00000, _00001, ... , _99999 ?
    – ruruskyi
    Jul 22, 2014 at 22:30
  • I'm not aware of any user alias number limit. You can test that fairly easily though. In any case such solution would be a nightmare to manage and wouldn't scale well. I would rather try to utilize mod_sql or implement a custom authentication module.
    – grekasius
    Jul 23, 2014 at 14:02

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.