[squid-users] Logs not showing ssl::servername

Fri Dec 2 08:55:34 UTC 2022

Hi *ngtech1ltd,*

Logformat:

logformat custom %ts.%03tu %>a %Ss/%03>Hs %ssl::>sni %ssl::bump_mode
%ssl::<cert_subject %<A %err_code %err_detail
access_log daemon:/var/log/squid/custom.log custom

Complete config for https:

# Handle HTTPS requests
https_port 3130 intercept ssl-bump cert=/etc/squid/ssl/squid.pem
acl SSL_port port 443
http_access allow SSL_port
acl step1 at_step SslBump1
acl step2 at_step SslBump2
acl step3 at_step SslBump3
ssl_bump peek step1 all

# Deny requests to proxy instance metadat
acl instance_metadata dst 169.254.169.254
http_access deny instance_metadata

# Filter HTTP requests based on the whitelist
acl allowed_http_sites dstdom_regex "/etc/squid/whitelist.txt"
http_access allow allowed_http_sites

# Filter HTTPS requests based on the whitelist
acl allowed_https_sites ssl::server_name_regex "/etc/squid/whitelist.txt"
ssl_bump peek step2 allowed_https_sites
ssl_bump splice step3 allowed_https_sites
ssl_bump terminate step2 all

http_access deny all

TBH reproducing it could be pretty hard. As far as I know that connection
comes from some agent that aws uses to grab data about what you are running
on the EC2, that EC2 machine is pretty old (so almost sure is running an
old agent version). I don´t see any usage on that service so I imagine is
not activate. Also the behavior I imagine has something to do with AWS
processing that connection and failing (for example because the Squid
machine has no rights to use it). Really the only strange thing is that it
logs 500 and TCP_TUNNEL, there is no way I can check if something else is
going on. Honestly if you don´t see the motive why it logs 500 and
TCP_TUNNEL I would probably give up on that... Is the only I spot strange.

I just took and old subnet and put there the Squid for some testing, then I
saw that (among a lot else logs that were going fine) there were one
strange log every few seconds and didn´t understand what´s going on. I was
thinking that it was my config file since I read a lot of blogs saying that
HTTPS transparent proxy without certificate was not possible (it looks like
it is). So I focused on fixing that but after trying a lot of different
sslbumb combinations I didn´t fix that.

Thanks!

El jue, 1 dic 2022 a las 16:41, Gabriel Vilariño (<gvilarino6 at gmail.com>)
escribió:

> Hi there,
>
> Sorry for the delay. I have problems to only log 1 request.
>
> I removed the internal ip that makes the request and one internal dns, but
> dont think that´s important. Also removed all machines that weren´t
> producing this traffic so we should only have the AWS arsernal request (on
> the access.log I only see one but could be a second one, however all of
> those produce exact same result).
>
> About the motivation Alex, really the only thing that concerns me is the
> strange log (TCP_TUNNEL and error 500). On the usage side, I can not tell
> if that call is working (going trough or not) since I don´t even use that
> service. I was evaluating how Squid works and simply run in that strange
> log. My final objective is to simply understand what´s going on (tunnel or
> 500) but there is nothing critical that I have to fix.
>
> Link: https://privfile.com/download.php?fid=6388c98c4ad19-MTQ5ODM= is
> valid for one day, password is "pepe" without "".
>
> Thanks!
>
>
>
>
>
>
>
>
> El mié, 30 nov 2022 a las 9:16, Gabriel Vilariño (<gvilarino6 at gmail.com>)
> escribió:
>
>> Hi again!
>>
>> Thanks for the info!
>>
>> Log with error code and error detail at the end, both "-":
>> 1669794718.051 INTERNAL_IP *TCP_TUNNEL/500*
>> arsenal.us-west-2.amazonaws.com splice /CN=
>> arsenal.us-west-2.amazonaws.com 54.240.254.131* - -*
>>
>> The cache.log with ALL,1 does not look to share a lot, in fact I don´t
>> see any messages referencing this transaction:
>>
>> 22/11/30 07:51:39 kid1| Current Directory is /
>> 2022/11/30 07:51:39 kid1| Creating missing swap directories
>> 2022/11/30 07:51:39 kid1| No cache_dir stores are configured.
>> 2022/11/30 07:51:39| Removing PID file (/run/squid.pid)
>> 2022/11/30 07:51:39 kid1| Current Directory is /
>> 2022/11/30 07:51:39 kid1| Starting Squid Cache version 5.7 for
>> x86_64-pc-linux-gnu...
>> 2022/11/30 07:51:39 kid1| Service Name: squid
>> 2022/11/30 07:51:39 kid1| Process ID 64694
>> 2022/11/30 07:51:39 kid1| Process Roles: worker
>> 2022/11/30 07:51:39 kid1| With 1024 file descriptors available
>> 2022/11/30 07:51:39 kid1| Initializing IP Cache...
>> 2022/11/30 07:51:39 kid1| DNS Socket created at [::], FD 9
>> 2022/11/30 07:51:39 kid1| DNS Socket created at 0.0.0.0, FD 10
>> 2022/11/30 07:51:39 kid1| Adding nameserver 127.0.0.53 from
>> /etc/resolv.conf
>> 2022/11/30 07:51:39 kid1| Adding domain dev.ops.mitekcloud.local from
>> /etc/resolv.conf
>> 2022/11/30 07:51:39 kid1| helperOpenServers: Starting 5/32
>> 'security_file_certgen' processes
>> 2022/11/30 07:51:39 kid1| Logfile: opening log
>> daemon:/var/log/squid/custom.log
>> 2022/11/30 07:51:39 kid1| Logfile Daemon: opening log
>> /var/log/squid/custom.log
>> 2022/11/30 07:51:40 kid1| Local cache digest enabled; rebuild/rewrite
>> every 3600/3600 sec
>> 2022/11/30 07:51:40 kid1| Store logging disabled
>> 2022/11/30 07:51:40 kid1| Swap maxSize 0 + 262144 KB, estimated 20164
>> objects
>> 2022/11/30 07:51:40 kid1| Target number of buckets: 1008
>> 2022/11/30 07:51:40 kid1| Using 8192 Store buckets
>> 2022/11/30 07:51:40 kid1| Max Mem  size: 262144 KB
>> 2022/11/30 07:51:40 kid1| Max Swap size: 0 KB
>> 2022/11/30 07:51:40 kid1| Using Least Load store dir selection
>> 2022/11/30 07:51:40 kid1| Current Directory is /
>> 2022/11/30 07:51:40 kid1| Finished loading MIME types and icons.
>> 2022/11/30 07:51:40 kid1| HTCP Disabled.
>> 2022/11/30 07:51:40 kid1| Pinger socket opened on FD 27
>> 2022/11/30 07:51:40 kid1| Squid plugin modules loaded: 0
>> 2022/11/30 07:51:40 kid1| Adaptation support is off.
>> 2022/11/30 07:51:40 kid1| Accepting HTTP Socket connections at conn13
>> local=[::]:3128 remote=[::] FD 23 flags=9
>> 2022/11/30 07:51:40 kid1| Accepting NAT intercepted HTTP Socket
>> connections at conn15 local=[::]:3129 remote=[::] FD 24 flags=41
>> 2022/11/30 07:51:40 kid1| Accepting NAT intercepted SSL bumped HTTPS
>> Socket connections at conn17 local=[::]:3130 remote=[::] FD 25 flags=41
>> 2022/11/30 07:51:40| pinger: Initialising ICMP pinger ...
>> 2022/11/30 07:51:40| pinger: ICMP socket opened.
>> 2022/11/30 07:51:40| pinger: ICMPv6 socket opened
>> 2022/11/30 07:51:41 kid1| storeLateRelease: released 0 objects
>> 2022/11/30 07:52:09 kid1| Preparing for shutdown after 3 requests
>> ... Starts ending the connections for shutdown, ends with next message...
>> *2022/11/30 07:52:40 kid1| Squid Cache (Version 5.7): Exiting normally.*
>>
>> I checked with further log levels but it outputs a lot of data (I know
>> this one is not for admins, I wanted to try to sent only the relevant logs
>> since those aws agents do several calls and I was not to only record one
>> transaction). Also if I needed, this is shared as an attachment?
>>
>> Thanks in advance!
>>
>>
>> El mar, 29 nov 2022 a las 21:52, Gabriel Vilariño (<gvilarino6 at gmail.com>)
>> escribió:
>>
>>> Thanks Alex!
>>>
>>> Here are the fixed logs:
>>> 1669726977.734 INTERNAL_CLIENT_IP TCP_TUNNEL/500
>>> arsenal.us-west-2.amazonaws.com splice /CN=
>>> arsenal.us-west-2.amazonaws.com 54.240.251.223
>>>
>>> As you can see, the destination is an aws service, more interesting, it
>>> effectively *logs the splice* action! That´s why I though it was
>>> letting the traffic go trough. Also the debug logs from SSL show this:
>>> 2022/11/29 10:32:38.943 kid1| 83,5| PeekingPeerConnector.cc(273) *startTunneling:
>>> will tunnel instead of negotiating TLS* # Last line from previously
>>> attached logs
>>>
>>> As far as I know this means *is getting to the TCP_TUNNEL, at that
>>> point it can not know anything about the internal status on the connection
>>> between client and host*. If not, *where I should be looking for this
>>> error? *Should try to review further the debug ssl logs to se if I fend
>>> something more useful? Maybe tcpdump? This could be just the end service
>>> failing on the request? Or is an error between Squid and the end sever?
>>>
>>> If I understand right the request that fails is the fake connect and I
>>> need to understand why. Also note almost same config logged this as
>>> TCP_TUNNEL/200 on version 3.5. But as said before, I really not sure
>>> how to check, since that service is just an agent installed on some aws
>>> machines and don´t know how to reproduce this behavior.
>>>
>>>
>>>
>>>
>>> Thanks again! Hope I answered fine since I didn´t get the answer email.
>>>
>>>
>>> El mar, 29 nov 2022 a las 14:06, Gabriel Vilariño (<gvilarino6 at gmail.com>)
>>> escribió:
>>>
>>>> Just got it solved. Was caused because of checking default access.log.
>>>> Using a new file solves all the problems.
>>>>
>>>> However, in this context, what means TCP_TUNNEL/500? is it because the
>>>> TLS handshake? I would like to know if it is tunneling correctly or is
>>>> having some trouble (not easy to test right now).
>>>>
>>>> Thanks!
>>>>
>>>> El mar, 29 nov 2022 a las 13:16, Gabriel Vilariño (<
>>>> gvilarino6 at gmail.com>) escribió:
>>>>
>>>>> Hi there,
>>>>>
>>>>> I am setting up an HTTP/HTTPS transparent proxy, meaning the clients
>>>>> not need any certificates for using the proxy. This works fine on version
>>>>> 3.5 of Squid, however after upgrading to 5.7 the behavior of the logs
>>>>> change:
>>>>>
>>>>> 1669723133.174   8037 10.184.19.220 TCP_TUNNEL/500 6207 CONNECT
>>>>> 54.240.253.128:443 - ORIGINAL_DST/54.240.253.128 -
>>>>>
>>>>> Directive: logformat squid %ts.%03tu %>a %Ss/%03>Hs %ssl::>sni
>>>>> %ssl::bump_mode ssl::>cert_subject %<ru
>>>>>
>>>>> On version 3.5 we were obtaining the domain name (an aws service) in
>>>>> the place of ORIGINAL_DST. Also now we are not seeing any information about
>>>>> the bump_mode in no one of the connections while before we were seeing it.
>>>>> One could trough that it could be because of the /500 message, however on a
>>>>> 200 one to docs.ansble.com it also don´t show any data on the sni
>>>>> field:
>>>>>
>>>>> 1669723513.363    332 10.184.19.220 TCP_TUNNEL/200 38192 CONNECT
>>>>> 104.26.0.234:443 - ORIGINAL_DST/104.26.0.234 -
>>>>>
>>>>> Also the 500 looks to come from the squid not understanding something
>>>>> on the SSL negotiation:
>>>>>
>>>>> 2022/11/29 10:32:38.943 kid1| 83,4| support.cc(248) check_domain:
>>>>> Verifying server domain arsenal.us-west-2.amazonaws.com to
>>>>> certificate name/subjectAltName arsenal.us-west-2.amazonaws.com 2022/11/29
>>>>> 10:32:38.943 kid1| 83,5| bio.cc(136) read: FD 28 read 347 <= 65535 2022/11/29
>>>>> 10:32:38.943 kid1| 83,5| Io.cc(91) Handshake: -1/0 for TLS connection
>>>>> 0x558453168970 over conn99 local=SQUID-INTERNAL-IP:44264 remote=
>>>>> 54.240.251.223:443 ORIGINAL_DST FD 28 flags=1 2022/11/29 10:32:38.943
>>>>> kid1| 83,2| PeerConnector.cc(256) handleNegotiationResult: ERROR: failure
>>>>> while establishing TLS connection on FD: 280x558452b68980*1 2022/11/29
>>>>> 10:32:38.943 kid1| 83,5| NegotiationHistory.cc(85) retrieveNegotiatedInfo:
>>>>> SSL connection info on FD 28 SSL version NONE/0.0 negotiated cipher 2022/11/29
>>>>> 10:32:38.943 kid1| 83,5| PeekingPeerConnector.cc(84)
>>>>> checkForPeekAndSpliceMatched: Will check for peek and splice on FD 28 2022/11/29
>>>>> 10:32:38.943 kid1| 83,5| PeekingPeerConnector.cc(395)
>>>>> serverCertificateVerified: HTTPS server CN:
>>>>> arsenal.us-west-2.amazonaws.com bumped: conn99
>>>>> local=SQUID-INTERNAL-IP:44264 remote=54.240.251.223:443 ORIGINAL_DST
>>>>> FD 28 flags=1
>>>>> 2022/11/29 10:32:38.943 kid1| 83,5| PeekingPeerConnector.cc(273)
>>>>> startTunneling: will tunnel instead of negotiating TLS
>>>>>
>>>>> It is clear that in creates the tunnel so the 500 probably is that
>>>>> error? Why the bump/sni messages never log anything (according to
>>>>> https://wiki.squid-cache.org/Features/SslPeekAndSplice they should
>>>>> log splice not -). This is the config for bumping:
>>>>>
>>>>>
>>>>>
>>>>> acl step1 at_step SslBump1
>>>>> acl step2 at_step SslBump2
>>>>> acl step3 at_step SslBump3
>>>>> ssl_bump peek step1 all
>>>>>
>>>>> .... http rules ...
>>>>>
>>>>> acl allowed_https_sites ssl::server_name_regex
>>>>> "/etc/squid/whitelist.txt"
>>>>> ssl_bump peek step2 allowed_https_sites
>>>>> ssl_bump splice step3 allowed_https_sites
>>>>> ssl_bump terminate step2 all
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Ip tables simply redirect:
>>>>>
>>>>> iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port
>>>>> 3129
>>>>> iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-port
>>>>> 3130 # https port on squid: https_port 3130 intercept ssl-bump
>>>>> cert=/etc/squid/ssl/dummy.pem
>>>>>
>>>>> Thanks in advance, i have been trying this for a week now reading a
>>>>> lot of posts but not luck...
>>>>>
>>>>
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