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    SSLBUMP without MITM

    Scheduled Pinned Locked Moved Cache/Proxy
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    • F
      fabiomello
      last edited by

      i am the person who did this change to opnsense, if you want and the maintaner of package accepts, i could do a pull request with this change.
      note: it works only with domain and not with complete urls, because dont do the intercept

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      • D
        doktornotor Banned
        last edited by

        @fabiomello:

        i am the person who did this change to opnsense, if you want and the maintaner of package accepts, i could do a pull request with this change.

        So, this could be pretty much rewritten to:

        setup ssl bump acl's

        acl bump_step1 at_step SslBump1
        acl bump_step2 at_step SslBump2
        acl bump_step3 at_step SslBump3
        acl bump_nobumpsites ssl::server_name "/usr/local/etc/squid/nobumpsites.acl"

        configure bump

        ssl_bump peek bump_step1 all
        ssl_bump splice all
        ssl_bump peek bump_step2 all
        ssl_bump splice bump_step3 all
        ssl_bump bump

        sslproxy_cert_error deny all

        @fabiomello:

        note: it works only with domain and not with complete urls, because dont do the intercept

        Yes, that is the problem. It does not intercept. Most of the code does nothing, as indicated above. It splices everything, you are finished with the stuff after the red line marked above [1].

        What the code in pfSense Squid attempts to do is: do NOT intercept 'Whitelist' ACL (that's what your no-op bump_nobumpsites ACL attempts to do but the code is just not used anywhere) and intercept the rest [2]

        [1] https://github.com/pfsense/FreeBSD-ports/blob/devel/www/pfSense-pkg-squid/files/usr/local/pkg/squid.inc#L1539
        [2]
        https://github.com/pfsense/FreeBSD-ports/blob/devel/www/pfSense-pkg-squid/files/usr/local/pkg/squid.inc#L1826
        https://github.com/pfsense/FreeBSD-ports/blob/devel/www/pfSense-pkg-squid/files/usr/local/pkg/squid.inc#L1887

        I must be missing something here.

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        • T
          tadaog
          last edited by

          doktornotor:

          You patch does getting the full https URL only and wonderfully, it we put ".*" at the whitelist, so that squidguard can do its job of denying or allowing it according its rules, exactly as it does with http.

          So, to summarize, putting in the whitelist field:

          .*

          and squidGuard does its jobs with http and https URLs!!!

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          • D
            doktornotor Banned
            last edited by

            OK, so I guess there are no changes really required for the SquidGuard + SSL usecase. Thanks for feedback.

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            • jimpJ
              jimp Rebel Alliance Developer Netgate
              last edited by

              To summarize, this does work with transparent interception without installing a CA on clients, but I can only get it to see the domain name, not the full URL as some in the thread have stated.

              • Squid General tab, Show Advanced Options, Custom ACLs (before auth)
              acl bump_step1 at_step SslBump1
              ssl_bump peek bump_step1 all
              ssl_bump splice all
              sslproxy_cert_error deny all
              
              • ACLs tab, whitelist:```
                .*
              
              When squidGuard blocks it kills the connection, it doesn't redirect or do anything nice.
              
              And naturally this doesn't let you see the body so no chance for AV or similar to check the contents.

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              • D
                doktornotor Banned
                last edited by

                @jimp: As I understand the previous post, there's really no need to put anything into Custom ACLs; the code is equivalent to what we have in the package already when you whitelist everything (.*) - there's

                ssl_bump splice whitelist
                ssl_bump bump all

                (and the second line won't have anything to match left when you've whitelisted everything)

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                • jimpJ
                  jimp Rebel Alliance Developer Netgate
                  last edited by

                  Ah, so all you need is the whitelist ".*" and the rest happens automatically? Cool. That does seem to work.

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                  • D
                    doktornotor Banned
                    last edited by

                    Yeah, it's basically "supertransparent", as in - no certificates forged/no need to install certs on clients. (And yeah, obviously it's limited in sense that you just get enough info about the connection for SquidGuard to do its job, but nothing else, i.e., no content filtering/AV/etc.)

                    Perhaps could use some hints in the GUI…

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                    • jimpJ
                      jimp Rebel Alliance Developer Netgate
                      last edited by

                      Would be nice to kick that in somehow when CA = "None" when using SSL Interception, or at least allow CA = None to be set in that case. It doesn't seem like that should be necessary since it isn't going to be using the CA when acting in that role. I haven't tried it though, maybe squid is dumb and still needs it set.

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                      • D
                        doktornotor Banned
                        last edited by

                        Yeah, afraid that's a no go, the certs are really required - plus, the ACL (whitelist) can be anything there and be changed at any time,  or have lines prepended/appended, really no way for Squid to figure out it's not going to need to fake any certs.

                        (But you could generate a temporary one for the CA in the background on each config resync; would need additional logic/code though in squid.inc. If you want something like this, I'd prefer having a separate checkbox for this, with some JS logic that'd gray out/disable unneeded MITM stuff in the GUI, and use a different ACL than the current whitelist for that, basically just use the built-in "all" one - like ssl_bump splice all)

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                        • S
                          shonjir
                          last edited by

                          I'm running a variation of this config in transparent mode with squidguard and shallalist quite successfully.

                          I'm not sure why exactly, but this configuration improves over basic step 1 peek and splice all by allowing logging of the server certificate (instead of just IP address), domain blocking of SSL sites via squidguard list, and provides an alternate splice operation for certain sites that for some reason cannot connect after the certificate name is captured.

                          # peek at client TLS-request to get SNI
                          # peek at server cert (for logging)
                          # splice earlySplice at step 3 only
                          acl earlySplice ssl::server_name "*.crashplan.com"
                          ssl_bump peek step1
                          ssl_bump peek step2 earlySplice
                          ssl_bump splice step3 earlySplice
                          ssl_bump splice all
                          sslproxy_cert_error deny all
                          
                          
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                          • D
                            doktornotor Banned
                            last edited by

                            Well yes, that will no doubt improve splice since you get whole lot more information available at steps 2/3, as explained here:
                            https://github.com/pfsense/FreeBSD-ports/blob/devel/www/pfSense-pkg-squid/files/usr/local/pkg/squid.inc#L1539

                            The above makes bumping impossible, however.

                            It's not possible to do zillion variants in the GUI. Use Advanced Options, Custom ACLs (before auth).

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                            • S
                              shonjir
                              last edited by

                              The above makes bumping impossible, however.

                              This is understood.  For my use case, I don't need full blown MiTM - logging the site name and simple domain blocking are sufficient.

                              Right now I'm using custom ACLs for this.  It's a hack (because it supersedes the auto-generated ssl_bump directives that follow), but it works.

                              It would be nice if it were available as a simple toggle in the config or if the various ssl config options were exposed for customization under 'advanced', but it works reasonably well as-is.

                              Thank you for your work making this tool available!

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                              • D
                                doktornotor Banned
                                last edited by

                                I'll see if something reasonable can be added for

                                • splice everything without bump (i.e., splice all)
                                • custom splice ACLs/settings (some advanced textarea burried somewhere, if you break it, your problem)

                                without overcomplicating the GUI and confusing everyone.

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                                • D
                                  doktornotor Banned
                                  last edited by

                                  OK, how's this?

                                  https://github.com/pfsense/FreeBSD-ports/pull/269

                                  ssl_mitm_mode_01.png
                                  ssl_mitm_mode_01.png_thumb
                                  ssl_mitm_mode_02.png
                                  ssl_mitm_mode_02.png_thumb

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                                  • jimpJ
                                    jimp Rebel Alliance Developer Netgate
                                    last edited by

                                    Looks great, we're getting that PR merged in right now, thanks!

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                                    • D
                                      doktornotor Banned
                                      last edited by

                                      Thanks for testing/feedback. Any volunteers to fixrewrite SquidGuard now? (No, I cannot do it. Tried many times, unable to work with that code for more than a couple of minutes.)

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                                      • F
                                        fabiomello
                                        last edited by

                                        e2guardian its more active…
                                        if you want to replace squidGuard with e2guardian i could do this!

                                        what you think?

                                        https://github.com/e2guardian/e2guardian

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                                        • D
                                          doktornotor Banned
                                          last edited by

                                          @fabiomello:

                                          e2guardian its more active…
                                          if you want to replace squidGuard with e2guardian i could do this!

                                          what you think?

                                          https://github.com/e2guardian/e2guardian

                                          Hmmm… good luck.

                                          • https://forum.pfsense.org/index.php?topic=87526.0
                                          • https://github.com/pfsense/pfsense-packages/pull/866
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                                          • jimpJ
                                            jimp Rebel Alliance Developer Netgate
                                            last edited by

                                            From the history there it looks like it had a similar problem to squidGuard. Whatever happens, it needs a ground-up rewrite with up-to-date style and practices all-around.

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                                            Do not Chat/PM for help!

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