[squid-users] SSL Bump Failures with Google and Wikipedia
Rafael Akchurin
rafael.akchurin at diladele.com
Fri Oct 6 05:24:08 UTC 2017
Hello Eliezer,
>From desktop ff/chrome goto youtube. It will be br encoded.
Best regards,
Rafael Akchurin
> Op 6 okt. 2017 om 02:43 heeft Eliezer Croitoru <eliezer at ngtech.co.il> het volgende geschreven:
>
> Hey Yuri and Rafael,
>
> I have tried to find a site which uses brotli compression but yet to find one.
> Also I have not seen any brotli request headers in firefox or chrome, maybe there is a specific browser which uses it?
>
> Thanks,
> Eliezer
>
> ----
> Eliezer Croitoru
> Linux System Administrator
> Mobile: +972-5-28704261
> Email: eliezer at ngtech.co.il
>
>
> -----Original Message-----
> From: squid-users [mailto:squid-users-bounces at lists.squid-cache.org] On Behalf Of Yuri
> Sent: Sunday, October 1, 2017 04:08
> To: squid-users at lists.squid-cache.org
> Subject: Re: [squid-users] SSL Bump Failures with Google and Wikipedia
>
> I guess in HTTP headers. =-O :-D
>
>
> 01.10.2017 7:05, Eliezer Croitoru пишет:
>> Hey Rafael,
>>
>> Where have you seen the details about brotli being used?
>>
>> Thanks,
>> Eliezer
>>
>> ----
>> Eliezer Croitoru
>> Linux System Administrator
>> Mobile: +972-5-28704261
>> Email: eliezer at ngtech.co.il
>>
>>
>>
>> -----Original Message-----
>> From: Rafael Akchurin [mailto:rafael.akchurin at diladele.com]
>> Sent: Sunday, October 1, 2017 01:16
>> To: Jeffrey Merkey <jeffmerkey at gmail.com>
>> Cc: Eliezer Croitoru <eliezer at ngtech.co.il>; squid-users
>> <squid-users at lists.squid-cache.org>
>> Subject: Re: [squid-users] SSL Bump Failures with Google and Wikipedia
>>
>> Hello Jeff,
>>
>> Do not forget Google and YouTube are now using brotli encoding
>> extensively, not only gzip.
>>
>> Best regards,
>> Rafael Akchurin
>>
>>> Op 30 sep. 2017 om 23:49 heeft Jeffrey Merkey <jeffmerkey at gmail.com>
>>> het
>> volgende geschreven:
>>>> On 9/30/17, Eliezer Croitoru <eliezer at ngtech.co.il> wrote:
>>>> Hey Jeffrey,
>>>>
>>>> What happens when you disable the next icap service this way:
>>>> icap_service service_avi_resp respmod_precache
>>>> icap://127.0.0.1:1344/cherokee bypass=0 adaptation_access
>>>> service_avi_resp deny all
>>>>
>>>> Is it still the same?
>>>> What I suspect is that the requests are defined to accept gzip
>>>> compressed objects and the icap service is not "gnuzip" them which
>>>> results in what you see.
>>>>
>>>> To make sure that squid is not at fault here try to disable both
>>>> icap services and then add then one at a time and see which of this
>>>> triangle is giving you trouble.
>>>> I enhanced an ICAP library which is written in GoLang at:
>>>> https://github.com/elico/icap
>>>>
>>>> And I have couple examples on how to work with http requests and
>>>> responses
>>>> at:
>>>> https://github.com/andybalholm/redwood/
>>>> https://github.com/andybalholm/redwood/search?utf8=%E2%9C%93&q=gzip&
>>>> t
>>>> ype=
>>>>
>>>> Let me know if you need help finding out the issue.
>>>>
>>>> All The Bests,
>>>> Eliezer
>>>>
>>>> ----
>>>> Eliezer Croitoru
>>>> Linux System Administrator
>>>> Mobile: +972-5-28704261
>>>> Email: eliezer at ngtech.co.il
>>>>
>>>>
>>>>
>>>> -----Original Message-----
>>>> From: squid-users [mailto:squid-users-bounces at lists.squid-cache.org]
>>>> On Behalf Of Jeffrey Merkey
>>>> Sent: Saturday, September 30, 2017 23:28
>>>> To: squid-users <squid-users at lists.squid-cache.org>
>>>> Subject: [squid-users] SSL Bump Failures with Google and Wikipedia
>>>>
>>>> Hello All,
>>>>
>>>> I have been working with the squid server and icap and I have been
>>>> running into problems with content cached from google and wikipedia.
>>>> Some sites using https, such as Centos.org work perfectly with ssl
>>>> bumping and I get the decrypted content as html and it's readable.
>>>> Other sites, such as google and wikipedia return what looks like
>>>> encrypted traffic, or perhaps mime encoded data, I am not sure which.
>>>>
>>>> Are there cases where squid will default to direct mode and not
>>>> decrypt the traffic? I am using the latest squid server 3.5.27. I
>>>> really would like to get this working with google and wikipedia. I
>>>> reviewed the page source code from the browser viewer and it looks
>>>> nothing like the data I am getting via the icap server.
>>>>
>>>> Any assistance would be greatly appreciated.
>>>>
>>>> The config I am using is:
>>>>
>>>> #
>>>> # Recommended minimum configuration:
>>>> #
>>>>
>>>> # Example rule allowing access from your local networks.
>>>> # Adapt to list your (internal) IP networks from where browsing #
>>>> should be allowed
>>>>
>>>> acl localnet src 127.0.0.1
>>>> acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
>>>> acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
>>>> acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
>>>> acl localnet src fc00::/7 # RFC 4193 local private network range
>>>> acl localnet src fe80::/10 # RFC 4291 link-local (directly
>>>> plugged) machines
>>>>
>>>> acl SSL_ports port 443
>>>> acl Safe_ports port 80 # http
>>>> acl Safe_ports port 21 # ftp
>>>> acl Safe_ports port 443 # https
>>>> acl Safe_ports port 70 # gopher
>>>> acl Safe_ports port 210 # wais
>>>> acl Safe_ports port 1025-65535 # unregistered ports
>>>> acl Safe_ports port 280 # http-mgmt
>>>> acl Safe_ports port 488 # gss-http
>>>> acl Safe_ports port 591 # filemaker
>>>> acl Safe_ports port 777 # multiling http
>>>> acl CONNECT method CONNECT
>>>>
>>>> #
>>>> # Recommended minimum Access Permission configuration:
>>>> #
>>>> # Deny requests to certain unsafe ports http_access deny !Safe_ports
>>>>
>>>> # Deny CONNECT to other than secure SSL ports http_access deny
>>>> CONNECT !SSL_ports
>>>>
>>>> # Only allow cachemgr access from localhost http_access allow
>>>> localhost manager http_access deny manager
>>>>
>>>> # We strongly recommend the following be uncommented to protect
>>>> innocent # web applications running on the proxy server who think
>>>> the only # one who can access services on "localhost" is a local
>>>> user #http_access deny to_localhost
>>>>
>>>> #
>>>> # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS #
>>>>
>>>> # Example rule allowing access from your local networks.
>>>> # Adapt localnet in the ACL section to list your (internal) IP
>>>> networks # from where browsing should be allowed http_access allow
>>>> localnet http_access allow localhost
>>>>
>>>> # And finally deny all other access to this proxy http_access deny
>>>> all
>>>>
>>>> # Squid normally listens to port 3128 #http_port 3128
>>>>
>>>> # Uncomment and adjust the following to add a disk cache directory.
>>>> #cache_dir ufs /usr/local/squid/var/cache/squid 100 16 256
>>>>
>>>> # Leave coredumps in the first cache dir coredump_dir
>>>> /usr/local/squid/var/cache/squid
>>>>
>>>> #
>>>> # Add any of your own refresh_pattern entries above these.
>>>> #
>>>> refresh_pattern ^ftp: 1440 20% 10080
>>>> refresh_pattern ^gopher: 1440 0% 1440
>>>> refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
>>>> refresh_pattern . 0 20% 4320
>>>>
>>>> http_port 3128 ssl-bump generate-host-certificates=on
>>>> dynamic_cert_mem_cache_size=4MB cert=/etc/squid/ssl_cert/myCA.pem
>>>> http_port 3129
>>>>
>>>> # SSL Bump Config
>>>> always_direct allow all
>>>> ssl_bump server-first all
>>>> sslproxy_cert_error deny all
>>>> sslproxy_flags DONT_VERIFY_PEER
>>>> sslcrtd_program /usr/local/squid/libexec/ssl_crtd -s /var/lib/ssl_db
>>>> -M 4MB sslcrtd_children 8 startup=1 idle=1
>>>>
>>>> # For squid 3.5.x
>>>> #sslcrtd_program /usr/local/squid/libexec/ssl_crtd -s
>>>> /var/lib/ssl_db -M 4MB
>>>>
>>>> # For squid 4.x
>>>> # sslcrtd_program /usr/local/squid/libexec/security_file_certgen -s
>>>> /var/lib/ssl_db -M 4MB
>>>>
>>>> icap_enable on
>>>> icap_send_client_ip on
>>>> icap_send_client_username on
>>>> icap_client_username_header X-Authenticated-User icap_preview_enable
>>>> on icap_preview_size 1024 icap_service service_avi_req
>>>> reqmod_precache icap://127.0.0.1:1344/request
>>>> bypass=1
>>>> adaptation_access service_avi_req allow all
>>>>
>>>> icap_service service_avi_resp respmod_precache
>>>> icap://127.0.0.1:1344/cherokee bypass=0 adaptation_access
>>>> service_avi_resp allow all
>>>>
>>>> Jeff
>>>> _______________________________________________
>>>> squid-users mailing list
>>>> squid-users at lists.squid-cache.org
>>>> http://lists.squid-cache.org/listinfo/squid-users
>>>>
>>>>
>>> Eliezer,
>>>
>>> Well, you certainly hit the nail on the head. I added the following
>>> code to check the content being sent to the icap server from squid,
>>> and here is what I found when I check the headers being sent from the
>>> remote web server:
>>>
>>> Code to check for content type and encoding received by the icap
>>> server added to c-icap:
>>>
>>> hdrs = ci_http_response_headers(req);
>>> content_type = ci_headers_value(hdrs, "Content-Type");
>>> if (content_type)
>>> ci_debug_printf(1,"srv_cherokee: content-type: %s\n",
>>> content_type);
>>>
>>> content_encoding = ci_headers_value(hdrs, "Content-Encoding");
>>> if (content_encoding)
>>> ci_debug_printf(1,"srv_cherokee: content-encoding: %s\n",
>>> content_encoding);
>>>
>>> And the output from scanned pages sent over from squid:
>>>
>>> srv_cherokee: init request 0x7f3dbc008eb0 pool hits:1 allocations: 1
>>> Allocating from objects pool object 5 pool hits:1 allocations: 1
>>> Geting buffer from pool 4096:1 Requested service: cherokee Read
>>> preview data if there are and process request
>>> srv_cherokee: content-type: text/html; charset=utf-8
>>> srv_cherokee: content-encoding: gzip <-- As you stated, I am
>>> getting gzipped data
>>> srv_cherokee: we expect to read :-1 body data Allow 204...
>>> Preview handler return allow 204 response
>>> srv_cherokee: release request 0x7f3dbc008eb0 Store buffer to long
>>> pool 4096:1 Storing to objects pool object 5 Log request to access
>>> log file /var/log/i-cap_access.log
>>>
>>>
>>> Wikipedia at https://en.wikipedia.org/wiki/HTTP_compression
>>> describes the process as:
>>>
>>> " ...
>>> Compression scheme negotiation[edit]
>>> In most cases, excluding the SDCH, the negotiation is done in two
>>> steps, described in
>>> RFC 2616:
>>>
>>> 1. The web client advertises which compression schemes it supports
>>> by including a list
>>> of tokens in the HTTP request. For Content-Encoding, the list in a
>>> field called Accept -
>>> Encoding; for Transfer-Encoding, the field is called TE.
>>>
>>> GET /encrypted-area HTTP/1.1
>>> Host: www.example.com
>>> Accept-Encoding: gzip, deflate
>>>
>>> 2. If the server supports one or more compression schemes, the
>>> outgoing data may be
>>> compressed by one or more methods supported by both parties. If
>>> this is the case, the
>>> server will add a Content-Encoding or Transfer-Encoding field in
>>> the HTTP response with
>>> the used schemes, separated by commas.
>>>
>>> HTTP/1.1 200 OK
>>> Date: mon, 26 June 2016 22:38:34 GMT
>>> Server: Apache/1.3.3.7 (Unix) (Red-Hat/Linux)
>>> Last-Modified: Wed, 08 Jan 2003 23:11:55 GMT
>>> Accept-Ranges: bytes
>>> Content-Length: 438
>>> Connection: close
>>> Content-Type: text/html; charset=UTF-8
>>> Content-Encoding: gzip
>>>
>>> The web server is by no means obligated to use any compression
>>> method -
>> this
>>> depends on the internal settings of the web server and also may
>>> depend on the internal
>>> architecture of the website in question.
>>>
>>> In case of SDCH a dictionary negotiation is also required, which
>>> may involve additional
>>> steps, like downloading a proper dictionary from .
>>> .."
>>>
>>>
>>> So, it looks like it is a feature of the browser. So, is it possible
>>> to have squid gunzip the data or configure the browser not to send
>>> the header to remove "Accept-Encoding: gzip, deflate" from the
>>> request sent to the remote server telling it to gzip the data?
>>>
>>> Thanks
>>>
>>> Jeff
>>> _______________________________________________
>>> squid-users mailing list
>>> squid-users at lists.squid-cache.org
>>> http://lists.squid-cache.org/listinfo/squid-users
>> _______________________________________________
>> squid-users mailing list
>> squid-users at lists.squid-cache.org
>> http://lists.squid-cache.org/listinfo/squid-users
>
>
>
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