Decrypting tcpdumps in Wireshark without key files (such as when FIPS is in use)
Problem this snippet solves: This procedure allows you to decrypt a tcpdump made on the F5 without requiring access to the key file. Despite multiple F5 pages that claim to document this procedure, none of them worked for me. This solution includes the one working iRule I found, trimmed down to the essentials. The bash command is my own, which generates a file with all the required elements from the LTM log lines generated by the iRule, needed to decrypt the tcpdump in Wireshark 3.x. How to use this snippet: Upgrade Wireshark to Version 3+. Apply this iRule to the virtual server targeted by the tcpdump: rule sessionsecret { when CLIENTSSL_HANDSHAKE { log local0.debug "CLIENT_RANDOM [SSL::clientrandom] [SSL::sessionsecret]" log local0.debug "RSA Session-ID:[SSL::sessionid] Master-Key:[SSL::sessionsecret]" } when SERVERSSL_HANDSHAKE { log local0.debug "CLIENT_RANDOM [SSL::clientrandom] [SSL::sessionsecret]" log local0.debug "RSA Session-ID:[SSL::sessionid] Master-Key:[SSL::sessionsecret]" } } Run tcpdump on the F5 using all required hooks to grab both client and server traffic. tcpdump -vvni 0.0:nnnp -s0 host <ip> -w /var/tmp/`date +%F-%H%M`.pcap Conduct tests to reproduce the problem, then stop the tcpdump (Control C) and remove the iRule from the virtual server. Collect the log lines into a file. cat /var/log/ltm | grep -oe "RSA Session.*$" -e "CLIENT_RANDOM.*$" > /var/tmp/pms Copy the .pcap and pms files to the computer running Wireshark 3+. Reference the "pms" file in "Wireshark > Preferences > Protocols > TLS > (Pre)-Master-Secret log filename" (hence the pms file name). Ensure that Wireshark > Analyze > Enabled Protocols > "F5 Ethernet trailer" and "f5ethtrailer" boxes are checked. Open the PCAP file in Wireshark; it will be decrypted. IMPORTANT TIP: Decrypting any large tcpdump brings a workstation to its knees, even to the point of running out of memory. A much better approach is to temporarily move the pms file, open the tcpdump in its default encrypted state, identify the problem areas using filters or F5 TCP conversation and export them to a much smaller file. Then you can move the pms file back to the expected location and decrypt the smaller file quickly and without significant impact on the CPU and memory. Code : Please refer to the "How to use this Code Snippet" section above. This procedure was successfully tested in 12.1.2 with a full-proxy virtual server. Tested this on version: 12.1
Ultimate irule debug - Capture and investigate
Problem this snippet solves: I decided to share this Irule for different reasons. When I help our community on devcentral, I regularly see people making recurring requests: How do I do to capture the queries header. How do I do to capture the response header. How do I check the information in the POST Request. How do I check response data (body). What cypher/protocol I use (SSL/TLS). I set up client certificate authentication but I do not know if it works and if I pass my certificate auth. I want to retrieve information from my authentication certificate (subject, issuer, …). My authenticating by certificate does not work and I get an error of what I have to do. I have latencies when dealing with my request. where does the latency come from (F5, server,..). I set up sso (kerberos delegation, json post, Form sso). I do not feel that my request is sent to the backend (or the kerberos token). Does F5 add information or modify the request/response. Which pool member has been selected My VS don’t answer (where does the problem come from) … instead of having an Irule for each request why not consolidate everything and provide a compact Irule. this Irule can help you greatly during your investigations and allows you to capture these different items: How to use this snippet: you have a function that allows you to activate the desired logs (1 to activate and 0 to disable) as describe below: array set app_arrway_referer { client_dest_ip_port 1 client_cert 1 http_request 1 http_request_release 1 http_request_payload 0 http_lb_selected 1 http_response 0 http_response_release 0 http_response_payload 0 http_time_process 0 } the posted logs will be preceded by a UID which will allow you to follow from the beginning to the end of the process of your request / answer. you can for example make a grep on the log to follow the complete process (request / answer). the UID is generated in the following way: `set uid [string range [AES::key 256] 15 23] client_dest_ip_port: this section will allow you to see source IP/Port and destination IP/Port. <CLIENT_ACCEPTED>: ----------- client_dest_ip_port ----------- <CLIENT_ACCEPTED>: uid: 382951fe9 - Client IP Src: 10.20.30.4:60419 <CLIENT_ACCEPTED>: uid: 382951fe9 - Client IP Dest:192.168.30.45:443 <CLIENT_ACCEPTED>: ----------- client_dest_ip_port ----------- client_cert: this section will allow you to check the result code for peer certificate verification ( and also if you have provide a certificate auth). moreover you will be able to recover the information of your authentication certficat (issuer, subject, …). if your authentication certificate that you provid is not valid an error message will be returned (ex: certificate chain too long, invalid CA certificate, …). all errors are listed in the link below: https://devcentral.f5.com/wiki/iRules.SSL__verify_result.ashx <HTTP_REQUEST>: ----------- client_cert ----------- <HTTP_REQUEST>: uid: 382951fe9 - cert number: 0 <HTTP_REQUEST>: uid: 382951fe9 - subject: OU=myOu, CN=youssef <HTTP_REQUEST>: uid: 382951fe9 - Issuer Info: DC=com, DC=domain, CN=MobIssuer <HTTP_REQUEST>: uid: 382951fe9 - cert serial: 22:00:30:5c:de:dd:ec:23:6e:b5:e6:77:bj:01:00:00:22:3c:dc <HTTP_REQUEST>: ----------- client_cert ----------- OR <HTTP_REQUEST>: ----------- client_cert ----------- <HTTP_REQUEST>: uid: 382951fe9 - No client certificate provided <HTTP_REQUEST>: ----------- client_cert ----------- http_request: This section allow you to retrieve the complete client HTTP request headers (that is, the method, URI, version, and all headers). I also added the protocol, the ciphers and the name of the vs used. <HTTP_REQUEST>: ----------- http_request ----------- <HTTP_REQUEST>: uid: 382951fe9 - protocol: https <HTTP_REQUEST>: uid: 382951fe9 - cipher name: ECDHE-RSA-AES128-GCM-SHA256 <HTTP_REQUEST>: uid: 382951fe9 - cipher version: TLSv1.2 <HTTP_REQUEST>: uid: 382951fe9 - VS Name: /Common/vs-myapp-443 <HTTP_REQUEST>: uid: 382951fe9 - Request: POST myapp.mydomain.com/browser-management/users/552462/playlist/play/api <HTTP_REQUEST>: uid: 382951fe9 - Host: myapp.mydomain.com <HTTP_REQUEST>: uid: 382951fe9 - Connection: keep-alive <HTTP_REQUEST>: uid: 382951fe9 - Content-Length: 290 <HTTP_REQUEST>: uid: 382951fe9 - Accept: application/json, text/javascript, */*; q=0.01 <HTTP_REQUEST>: uid: 382951fe9 - X-Requested-With: XMLHttpRequest <HTTP_REQUEST>: uid: 382951fe9 - User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.106 Safari/537.36 <HTTP_REQUEST>: uid: 382951fe9 - Referer: https://myapp.mydomain.com/ <HTTP_REQUEST>: uid: 382951fe9 - Accept-Encoding: gzip, deflate, sdch, br <HTTP_REQUEST>: uid: 382951fe9 - Accept-Language: en-US,en;q=0.8 <HTTP_REQUEST>: uid: 382951fe9 - Cookie: RLT=SKjpfdkFDKjkufd976HJhldds=; secureauth=true; STT="LKJSDKJpjslkdjslkjKJSHjfdskjhoLHkjh78dshjhd980szKJH"; ASP.SessionId=dsliulpoiukj908798dsjkh <HTTP_REQUEST>: uid: 382951fe9 - X-Forwarded-For: 10.10.10.22 <HTTP_REQUEST>: ----------- http_request ----------- http_request_release: This section triggered when the system is about to release HTTP data on the serverside of the connection. This event is triggered after modules process the HTTP request. So it will allow you to check request after F5 process. suppose that you have put APM with SSO kerberos, you will be able to see the kerberos token insert by F5. Or XFF insert by HTTP profile… <HTTP_REQUEST_RELEASE>: ----------- http_request_release ----------- <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - VS Name: /Common/vs-myapp-443 <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - Request: GET myapp.mydomain.com/browser-management/users/552462/playlist/play/api <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - Host: myapp.mydomain.com <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - Connection: keep-alive <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - Accept: application/json, text/javascript, */*; q=0.01 <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - X-Requested-With: XMLHttpRequest <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.106 Safari/537.36 <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - Referer: https://myapp.mydomain.com/ <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - Accept-Encoding: gzip, deflate, sdch, br <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - Accept-Language: en-US,en;q=0.8 <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - Cookie: RLT=SKjpfdkFDKjkufd976HJhldds=; secureauth=true; STT="LKJSDKJpjslkdjslkjKJSHjfdskjhoLHkjh78dshjhd980szKJH"; ASP.SessionId=dsliulpoiukj908798dsjkh <HTTP_REQUEST_RELEASE>: uid: 382951fe9 - X-Forwarded-For: 10.10.10.22 <HTTP_REQUEST_RELEASE>: ----------- http_request_release ----------- http_request_payload: This section will allow you to retrieve the HTTP request body. <HTTP_REQUEST>: ----------- http_request_payload ----------- <HTTP_REQUEST>: uid: 382951fe9 - Content-Length header null in request If GET or POST withtout content) <HTTP_REQUEST>: ----------- http_request_payload ----------- or <HTTP_REQUEST>: ----------- http_request_payload ----------- <HTTP_REQUEST>: uid: 382951fe9 - post payload: { id: 24, retrive: 'identity', service: 'IT'} <HTTP_REQUEST>: ----------- http_request_payload ----------- http_lb_selected This section will allow you to you to see which pool member has been selected. Once the pool memeber has been selected, you will not see this logs again until another load balancing decision will be made. If you want to see the selected pool memeber for each request you can see this information in "http_response". <HTTP_REQUEST>: ----------- http_lb_selected ----------- <LB_SELECTED>: uid: 382951fe9 - pool member IP: /Common/pool-name 10.22.33.54 443 <HTTP_REQUEST>: ----------- http_lb_selected ----------- http_response: This section will allow you to retrieve the response status and header lines from the server response. You can also see which pool member has been selected. <HTTP_RESPONSE>: ----------- http_response ----------- <HTTP_RESPONSE>: uid: 382951fe9 - status: 200 <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - pool member IP: /Common/pool-name 10.22.33.54 443 <HTTP_RESPONSE>: uid: 382951fe9 - Cache-Control: no-cache <HTTP_RESPONSE>: uid: 382951fe9 - Pragma: no-cache <HTTP_RESPONSE>: uid: 382951fe9 - Content-Type: application/json; charset=utf-8 <HTTP_RESPONSE>: uid: 382951fe9 - Expires: -1 <HTTP_RESPONSE>: uid: 382951fe9 - Server: Microsoft-IIS/8.5 <HTTP_RESPONSE>: uid: 382951fe9 - X-Powered-By: ASP.NET <HTTP_RESPONSE>: uid: 382951fe9 - Date: Fri, 28 Oct 2018 06:46:59 GMT <HTTP_RESPONSE>: uid: 382951fe9 - Content-Length: 302 <HTTP_RESPONSE>: ----------- http_response ----------- http_response_release: This section triggered when the system is about to release HTTP data on the clientside of the connection. This event is triggered after modules process the HTTP response. you can make sure that the answer has not been altering after the f5 process. You can also see which pool member has been selected. <HTTP_RESPONSE_RELEASE>: ----------- http_response_release ----------- <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - status: 200 <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - pool member IP: /Common/pool-name 10.22.33.54 443 <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Cache-Control: no-cache <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Pragma: no-cache <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Content-Type: application/json; charset=utf-8 <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Expires: -1 <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Server: Microsoft-IIS/8.5 <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - X-Powered-By: ASP.NET <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Date: Fri, 28 Oct 2018 06:46:59 GMT <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Content-Length: 302 <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Strict-Transport-Security: max-age=16070400; includeSubDomains <HTTP_RESPONSE_RELEASE>: ----------- http_response_release ----------- http_response_payload: This section will allow you to Collects an amount of HTTP body data that you specify. <HTTP_RESPONSE_DATA>: ----------- http_response_payload ----------- <HTTP_RESPONSE_DATA>: uid: 382951fe9 - Response (Body) payload: { "username" : "youssef", "genre" : "unknown", "validation-factors" : { "validationFactors" : [ { "name" : "remote_address", "value" : "127.0.0.1" } ] }} <HTTP_RESPONSE_DATA>: ----------- http_response_payload ----------- http_time_process: this part will allow you to put back information which can be useful to you to target the latency problematic. it is clear that it is not precise and that f5 offers other tools for that. but you will be able to quickly see which elements take the most time to be processed. you will be able to see how long f5 takes to process the request, the response and how long the backend server takes time to respond. <HTTP_RESPONSE_RELEASE>: ----------- http_time_process ----------- <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Time to request (F5 request time) = 5 (ms) <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Time to response (F5 response time) = 0 (ms) <HTTP_RESPONSE_RELEASE>: uid: 382951fe9 - Time to server (server backend process time) = 4 (ms) <HTTP_RESPONSE_RELEASE>: ----------- http_time_process ----------- Code : when CLIENT_ACCEPTED { # set a unique id for transaction set uid [string range [AES::key 256] 15 23] # set what's you want to retrieve 0 or 1 array set app_arrway_referer { client_dest_ip_port 1 client_cert 1 http_request 1 http_request_release 1 http_request_payload 1 http_lb_selected 1 http_response 1 http_response_release 1 http_response_payload 1 http_time_process 1 } if {$app_arrway_referer(client_dest_ip_port)} { log local0. " ----------- client_dest_ip_port ----------- " clientside { log local0. "uid: $uid - Client IP Src: [IP::client_addr]:[TCP::client_port]" } log local0. "uid: $uid - Client IP Dest:[IP::local_addr]:[TCP::local_port]" log local0. " ----------- client_dest_ip_port ----------- " log local0. " " } } when HTTP_REQUEST { set http_request_time [clock clicks -milliseconds] # Triggered when the system receives a certificate message from the client. The message may contain zero or more certificates. if {$app_arrway_referer(client_cert)} { log local0. " ----------- client_cert ----------- " # SSL::cert count - Returns the total number of certificates that the peer has offered. if {[SSL::cert count] > 0}{ # Check if there was no error in validating the client cert against LTM's server cert if { [SSL::verify_result] == 0 }{ for {set i 0} {$i < [SSL::cert count]} {incr i}{ log local0. "uid: $uid - cert number: $i" log local0. "uid: $uid - subject: [X509::subject [SSL::cert $i]]" log local0. "uid: $uid - Issuer Info: [X509::issuer [SSL::cert $i]]" log local0. "uid: $uid - cert serial: [X509::serial_number [SSL::cert $i]]" } } else { # https://devcentral.f5.com/s/wiki/iRules.SSL__verify_result.ashx (OpenSSL verify result codes) log local0. "uid: $uid - Cert Info: [X509::verify_cert_error_string [SSL::verify_result]]" } } else { log local0. "uid: $uid - No client certificate provided" } log local0. " ----------- client_cert ----------- " log local0. " " } if {$app_arrway_referer(http_request)} { log local0. " ----------- http_request ----------- " if { [PROFILE::exists clientssl] == 1 } { log local0. "uid: $uid - protocol: https" log local0. "uid: $uid - cipher name: [SSL::cipher name]" log local0. "uid: $uid - cipher version: [SSL::cipher version]" } log local0. "uid: $uid - VS Name: [virtual]" log local0. "uid: $uid - Request: [HTTP::method] [HTTP::host][HTTP::uri]" foreach aHeader [HTTP::header names] { log local0. "uid: $uid - $aHeader: [HTTP::header value $aHeader]" } log local0. " ----------- http_request ----------- " log local0. " " } set collect_length_request [HTTP::header value "Content-Length"] set contentlength 1 if {$app_arrway_referer(http_request_payload)} { if { [catch { if { $collect_length_request > 0 && $collect_length_request < 1048577 } { set collect_length $collect_length_request } else { set collect_length 1048576 } if { $collect_length > 0 } { HTTP::collect $collect_length_request set contentlength 1 } }] } { # no DATA in POST Request log local0. " ----------- http_request_payload ----------- " log local0. "uid: $uid - Content-Length header null in request" log local0. " ----------- http_request_payload ----------- " log local0. " " set contentlength 0 } } } when HTTP_REQUEST_DATA { if {$app_arrway_referer(http_request_payload)} { log local0. " ----------- http_request_payload ----------- " if {$contentlength} { set postpayload [HTTP::payload] log local0. "uid: $uid - post payload: $postpayload" #HTTP::release } log local0. " ----------- http_request_payload ----------- " log local0. " " } } when HTTP_REQUEST_RELEASE { if {$app_arrway_referer(http_request_release)} { log local0. " ----------- http_request_release ----------- " if { [PROFILE::exists clientssl] == 1 } { log local0. "uid: $uid - cipher protocol: https" log local0. "uid: $uid - cipher name: [SSL::cipher name]" log local0. "uid: $uid - cipher version: [SSL::cipher version]" } log local0. "uid: $uid - VS Name: [virtual]" log local0. "uid: $uid - Request: [HTTP::method] [HTTP::host][HTTP::uri]" foreach aHeader [HTTP::header names] { log local0. "uid: $uid - $aHeader: [HTTP::header value $aHeader]" } log local0. " ----------- http_request_release ----------- " log local0. " " } set http_request_time_release [clock clicks -milliseconds] } when LB_SELECTED { if {$app_arrway_referer(http_lb_selected)} { log local0. " ----------- http_lb_selected ----------- " log local0. "uid: $uid - pool member IP: [LB::server]" log local0. " ----------- http_lb_selected ----------- " log local0. " " } } when HTTP_RESPONSE { set http_response_time [clock clicks -milliseconds] set content_length [HTTP::header "Content-Length"] if {$app_arrway_referer(http_response)} { log local0. " ----------- http_response ----------- " log local0. "uid: $uid - status: [HTTP::status]" log local0. "uid: $uid - pool member IP: [LB::server]" foreach aHeader [HTTP::header names] { log local0. "uid: $uid - $aHeader: [HTTP::header value $aHeader]" } log local0. " ----------- http_response ----------- " log local0. " " } if {$app_arrway_referer(http_response_payload)} { if { $content_length > 0 && $content_length < 1048577 } { set collect_length $content_length } else { set collect_length 1048576 } if { $collect_length > 0 } { HTTP::collect $collect_length } } } when HTTP_RESPONSE_DATA { if {$app_arrway_referer(http_response_payload)} { log local0. " ----------- http_response_payload ----------- " set payload [HTTP::payload] log local0. "uid: $uid - Response (Body) payload: $payload" log local0. " ----------- http_response_payload ----------- " log local0. " " } } when HTTP_RESPONSE_RELEASE { set http_response_time_release [clock clicks -milliseconds] if {$app_arrway_referer(http_response_release)} { log local0. " ----------- http_response_release ----------- " log local0. "uid: $uid - status: [HTTP::status]" log local0. "uid: $uid - pool member IP: [LB::server]" foreach aHeader [HTTP::header names] { log local0. "uid: $uid - $aHeader: [HTTP::header value $aHeader]" } log local0. " ----------- http_response_release ----------- " log local0. " " } if {$app_arrway_referer(http_time_process)} { log local0. " ----------- http_time_process ----------- " log local0.info "uid: $uid - Time to request (F5 request time) = [expr $http_request_time - $http_request_time_release] (ms)" log local0.info "uid: $uid - Time to response (F5 response time) = [expr $http_response_time - $http_response_time_release] (ms)" log local0.info "uid: $uid - Time to server (server backend process time) = [expr $http_request_time_release - $http_response_time] (ms)" log local0. " ----------- http_time_process ----------- " log local0. " " } } Tested this on version: 13.0iRule Event Order Flowchart
Problem this snippet solves The original contributions are from HTTP Event Order -- Access Policy Manager - DevCentral (f5.com) I have updated this code example to use draw.io so that anyone can update diagram for required changes. Attempt to diagram a logic path for iRule event processing visually. There is special emphasis with ACCESS events as their lifecycle is a bit more complicated. These events should cover the most common use cases to customize ACCESS functionality. How to use this snippet This diagram can be updated via the free draw.io at https://app.diagrams.net/ Tested this on version No Version Found
Add SameSite attribute to APM Cookies
Problem this snippet solves: This irule add SameSite attribute with value None to APM Cookies. related to Chrome 80 behavior change : Cookies default to SameSite=Lax When you put "SameSite=None", you must have the "Secure" attribute set to the cookie. How to use this snippet: Add the irule to a Virtual Server. Change value of the attribute from None to desired value. Pay attention to possible interferences with other irules applied to Virtual Servers. Code : when RULE_INIT { set static::apm_cookies { "F5_fullWT" "F5_HT_shrinked" "F5_ST" "LastMRH_Session" "MRHSequence" "MRHSession" "MRHSHint" "TIN" "F5_VdiUserClientChoicecitrix" "F5_VdiUserClientChoicevmware_view" } } when CLIENT_ACCEPTED { ACCESS::restrict_irule_events disable } when HTTP_RESPONSE_RELEASE { foreach apm_cookie ${static::apm_cookies} { if { [HTTP::cookie exists ${apm_cookie}] } { HTTP::cookie attribute ${apm_cookie} insert "SameSite" None if { ![HTTP::cookie attribute ${apm_cookie} exists "secure"] } { HTTP::cookie attribute ${apm_cookie} insert "Secure" } } } } Tested this on version: 12.1Set the SameSite Cookie Attribute for Web Application and BIG-IP Module Cookies
Problem this snippet solves: UPDATE: Note that the work for SameSite is evolving rapidly and this new entry should be considered over the iRule contents below. Chrome (and likely other browsers to follow) will enforce the SameSite attribute on HTTP cookies to Lax beginning soon (initial limited rollout week of Feb 17th, 2020) which could impact sites that don't explicitly set the attribute. This iRule will set the SameSite attribute in all BIG-IP and app cookies found in Set-Cookie headers. Note that this would not modify cookies set on the client using javascript or other methods. Contributed by: hoolio How to use this snippet: Apply the iRule to the appropriate virtual servers. Code : when HTTP_RESPONSE_RELEASE { # Set all BIG-IP and app cookies found in Set-Cookie headers using this iRule to: # none: Cookies will be sent in both first-party context and cross-origin requests; # however, the value must be explicitly set to None and all browser requests must # follow the HTTPS protocol and include the Secure attribute which requires an encrypted # connection. Cookies that don't adhere to that requirement will be rejected. # Both attributes are required together. If just None is specified without Secure or # if the HTTPS protocol is not used, the third-party cookie will be rejected. # # lax: Cookies will be sent automatically only in a first-party context and with HTTP GET requests. # SameSite cookies will be withheld on cross-site sub-requests, such as calls to load images or iframes, # but will be sent when a user navigates to the URL from an external site, e.g., by following a link. # # strict: browser never sends cookies in requests to third party domains # # Above definitions from: https://docs.microsoft.com/en-us/microsoftteams/platform/resources/samesite-cookie-update # # Note: this iRule would not modify cookies set on the client using Javascript or other methods outside of Set-Cookie headers! set samesite_security "none" # Log debug to /var/log/ltm? (1=yes, 0=no) set cookie_debug 1 set cookie_names [HTTP::cookie names] if {$cookie_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: \[HTTP::header values {Set-Cookie}\]: [HTTP::header values {Set-Cookie}]"} if {$cookie_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: \$cookie_names ([llength $cookie_names]): $cookie_names"} foreach a_cookie $cookie_names { # Remove any prior instances of SameSite attributes HTTP::cookie attribute $a_cookie remove {samesite} # Insert a new SameSite attribute HTTP::cookie attribute $a_cookie insert {samesite} $samesite_security # If samesite attribute is set to None, then the Secure flag must be set for browsers to accept the cookie if {[string equal -nocase $samesite_security "none"]} { HTTP::cookie secure $a_cookie enable } } if {$cookie_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: Set-Cookie header values: [HTTP::header values {Set-Cookie}]"} } Tested this on version: 13.0iRule for AFM IP Intelligence security policy to work with HTTP XFF (X-Forwarded-For) headers
Code is community submitted, community supported, and recognized as ‘Use At Your Own Risk’. Short Description As mentioned in article https://my.f5.com/manage/s/article/K73304774 (K73304774: AFM + IP Intelligence does not block requests using X-Forwarded-For header value) the AFM can't work with XFF headers unless decrypting traffic and using the IP Intelligence i in a irule, which is comlex but there is an easier way and I will show you how! 😎 Description of the irule "virtual" command: https://clouddocs.f5.com/api/irules/virtual.html If the XFF has multiple values better also see article https://my.f5.com/manage/s/article/K70310105 (K70310105: ASM with IP-intelligence cannot reject request based on x-forwarded-for) that if for the ASM/AWAF but the same principle applies here. Problem solved by this Code Snippet The iRule below is attached on a virtual server that decrypts the HTTPS traffic, then the traffic is forwarded to another second virtual server where the IP Intelligence policy is assigned. How to use this Code Snippet Make 2 virtial servers as the first VS will decrypt the traffic (you also attach the iRule to the first VS) and will lead to the second VS and the second VS will have an LTM pool and the IPI policy attached to it. Keep in mind that if the traffic is too high there could be a bottleneck because of the internal channel between the two VS. Code Snippet Meta Information Version: 16.1.3.4 Coding Language: TCL/iRule Full Code Snippet when HTTP_REQUEST { if { [HTTP::header exists "X-Forwarded-For"] } { snat [HTTP::header "X-Forwarded-For"] log local0. "Client IP changed from [IP::client_addr] to [HTTP::header "X-Forwarded-For"]" } virtual second_vs }Performance Logging iRule (Rule_http_log)
Problem this snippet solves: Here's a logging iRule. You'll need a HSL syslog pool to log too. Various bits gathered from other posts on DevCentral. Sharing in case there is interest. Make sure your rsyslogd is setup to use the newer syslog format like RFC-5424 including milliseconds and timezone info. Includes Country (co) and logs individual request times for each request on a HTTP/1.1 connection. To configure F5 logging to use milliseconds and timezone, disable logging in the gui and use tmsh edit sys syslog and something like: include " # short hostnames options { use_fqdn(no); }; # Remote syslog in RFC5424 - Tim Riker <Tim@Rikers.org> destination remotesyslog { syslog(\"10.1.2.3\" transport(\"udp\") port(51443) ts_format(iso)); }; log { source(s_syslog_pipe); destination(remotesyslog); }; " Uses upvar and proc. Tested on 11.6 - 15.1 This tracks connection info in a table and then copies that down to the per-request log() to handle reporting on http2. This version works around a BIG-IP bug where HTTP::version does not report 2 or higher for http2 and later requests. With http2 profiles, subsequent requests using the same connection can generate this error in the logs if HTTP::respond HTTP::redirect or HTTP::retry is called from and earlier iRule. Reorder your iRules to avoid this. <HTTP_REQUEST> - No HTTP header is cached - ERR_NOT_SUPPORTED (line 1) invoked from within "HTTP::method" How to use this snippet: Add this iRule to whatever virtual hosts you desire. I always add it as the first rule. If you have a rule that sets headers you want to track, you may want this after the rule that sets headers. Interesting Splunk queries can be created like: index=* perflog | timechart avg(cpu_5sec) by host limit=10 to show load across multiple F5s. index=* perflog | timechart max(upstream_time) by http_host limit=10 to show long request times by http_host Any other iRule may add things to the log() array and those will get added to the single hsl output. If you create a dg_http_log datagroup, that will be used to filter what gets logged. Tested on version: 13.0 - 15.1 # Rule_http_log # http logging - Tim Riker <Tim@Rikers.org> # bits taken from this post: # https://devcentral.f5.com/questions/irule-for-getting-total-response-time-server-response-time-and-server-connection-time # iRule performance tracking # https://devcentral.f5.com/questions/Timing-iRules timing on # timing is on by default in 11.5.0+ to see stats: # tmsh show ltm rule Rule_http_log # # if the dg_http_log datagroup exists then vips or hosts/paths in dg_http_log that start with # "NONE" no logging (really anything other than empty) # "INFO" normal logging # "FINE" full request and response headers and CLIENT_CLOSED # # upstream_time := 15000 in the datagroup to log all requests over 15 seconds # # example: # "/Common/vs_www.example.com_HTTPS" := "FINE" - logged including CLIENT_CLOSED # "www.example.com/" := "INFO" - logged # "www.example.com/somepath" := "FINE" - full headers # "www.example.com/otherpath" := "NONE" - not logged when RULE_INIT { # hostname up to first dot set static::hostname [getfield [info hostname] "." 1] } # not calling /Common/proc:hsllog as this logs when the request occurred # instead of the time it calls hsllog at the end of the request proc hsllog {time mylog} { upvar 1 $mylog log # https://tools.ietf.org/html/rfc5424 <local0.info>version rfc-3339time host procid msgid structured_data log # should be able to use a "Z" here instead of "+00:00" but our splunk logs don't handle that # 134 = local0.info set output "<134>1 [clock format [string range $time 0 end-3] -gmt 1 -format %Y-%m-%dT%H:%M:%S.[string range $time end-2 end]+00:00] ${static::hostname} httplog [TMM::cmp_group].[TMM::cmp_unit] - -" foreach key [lsort [array names log]] { if { ($log($key) matches_regex {[\" ;,:]}) } { append output " $key=\"[string map {\" "|"} $log($key)]\"" } else { append output " $key=$log($key)" } } # avoid marking virtual server up when hsl pool is up # https://support.f5.com/csp/article/K14505 set hsl pool_syslog HSL::send [HSL::open -proto UDP -pool $hsl] $output } when CLIENT_ACCEPTED { # calculate and track milliseconds # is this / 1000 guaranteed to be clock seconds? TCL docs say no, but it looks like on f5 it is. set tcp_start_time [clock clicks -milliseconds] set log(loglevel) 0 if { [class exists dg_http_log] } { # virtual name entries need to be full path, ie: /Common/vs_www.example.com_HTTP switch -- [string range [class match -value -- [virtual name] equals dg_http_log] 0 3] { "FINE" { set log(loglevel) 2 } "INFO" { set log(loglevel) 1 } default { set log(loglevel) 0 } } } table set -subtable [IP::client_addr]:[TCP::client_port] loglevel $log(loglevel) table set -subtable [IP::client_addr]:[TCP::client_port] tmm "[TMM::cmp_group].[TMM::cmp_unit]" table set -subtable [IP::client_addr]:[TCP::client_port] client_addr [IP::client_addr] table set -subtable [IP::client_addr]:[TCP::client_port] client_port [TCP::client_port] table set -subtable [IP::client_addr]:[TCP::client_port] cpu_5sec [cpu usage 5secs] table set -subtable [IP::client_addr]:[TCP::client_port] virtual_name [virtual name] set co [whereis [IP::client_addr] country] if { $co eq "" } { set co unknown } table set -subtable [IP::client_addr]:[TCP::client_port] co $co } when HTTP_REQUEST { set http_request_time [clock clicks -milliseconds] set keys [table keys -subtable [IP::client_addr]:[TCP::client_port]] foreach key $keys { set log($key) "[table lookup -subtable "[IP::client_addr]:[TCP::client_port]" "$key"]" } if {[HTTP::has_responded]} { # The rule should come BEFORE any rules that do things like redirects set log(http_has_responded) [HTTP::has_responded] set log(loglevel) 1 set log(event) HTTP_REQUEST call hsllog $http_request_time log return } if { [class exists dg_http_log] } { set logsetting [class match -value -- [HTTP::host][HTTP::uri] starts_with dg_http_log] if { $logsetting ne "" } { # override log(loglevel) if we found something switch -- [string range $logsetting 0 3] { "FINE" { set log(loglevel) 2 } "INFO" { set log(loglevel) 1 } default { set log(loglevel) 0 } } } } set log(http_host) [HTTP::host] set log(http_uri) [HTTP::uri] set log(http_method) [HTTP::method] # request_num might not be accurate for HTTP2 set log(request_num) [HTTP::request_num] set log(request_size) [string length [HTTP::request]] # BUG http2 reported as http1 in pre 16.x # https://cdn.f5.com/product/bugtracker/ID842053.html set log(http_version) [HTTP::version] if { [catch \[HTTP2::version\] result] == 1 } { if { $result contains "Operation not supported" } { #log local0. "HTTP version is: [HTTP::version]" } else { set h2ver [eval "\HTTP2::version"] # we might have http2 support, but not be http2 if { $h2ver != 0 } { set log(http_version) $h2ver } } } #log local0. "http_version = $log(http_version)" if { $log(loglevel) > 1 } { foreach {header} [HTTP::header names] { set log(req-$header) [HTTP::header $header] } } else { foreach {header} {"connection" "content-length" "keep-alive" "last-modified" "policy-cn" "referer" "transfer-encoding" "user-agent" "x-forwarded-for" "x-forwarded-proto" "x-forwarded-scheme"} { if { [HTTP::header exists $header] } { set log(req-$header) [HTTP::header $header] } } } } when LB_SELECTED { set lb_selected_time [clock clicks -milliseconds] set log(server_addr) [LB::server addr] set log(server_port) [LB::server port] set log(pool) [LB::server pool] } when SERVER_CONNECTED { set log(connection_time) [expr {[clock clicks -milliseconds] - $lb_selected_time}] set log(snat_addr) [IP::local_addr] set log(snat_port) [TCP::local_port] } when LB_FAILED { set log(event_info) [event info] } when HTTP_REJECT { set log(http_reject) [HTTP::reject_reason] } when HTTP_REQUEST_SEND { set http_request_send_time [clock clicks -milliseconds] } when HTTP_RESPONSE { set log(upstream_time) [expr {[clock clicks -milliseconds] - $http_request_send_time}] set log(http_status) [HTTP::status] if { $log(loglevel) > 1 } { foreach {header} [HTTP::header names] { set log(res-$header) [HTTP::header $header] } } else { foreach {header} {"cache-control" "connection" "content-encoding" "content-length" "content-type" "content-security-policy" "keep-alive" "last-modified" "location" "server" "www-authenticate"} { if { [HTTP::header exists $header] } { set log(res-$header) [HTTP::header $header] } } } # if logging is off, but upstream_time is over threshold in datagroup, log anyway if { ($log(loglevel) < 1) && [class exists dg_http_log] } { set log_upstream_time [class match -value -- upstream_time equals dg_http_log] if {$log_upstream_time ne "" && $log(upstream_time) >= $log_upstream_time} { set log(over_upstream_time) $log_upstream_time set log(loglevel) 1 } } } when HTTP_RESPONSE_RELEASE { if { [info exists http_request_time] } { set log(http_time) "[expr {[clock clicks -milliseconds] - $http_request_time}]" # push http_time into table so CLIENT_CLOSED can see it in HTTP/2 table set -subtable [IP::client_addr]:[TCP::client_port] http_time $log(http_time) } else { set http_request_time [clock clicks -milliseconds] } set log(event) HTTP_RESPONSE_RELEASE if { $log(loglevel) > 0 } { call hsllog $http_request_time log } } when HTTP_DISABLED { set log(http_passthrough_reason) [HTTP::passthrough_reason] } when CLIENT_CLOSED { # grab log() values from table set keys [table keys -subtable [IP::client_addr]:[TCP::client_port]] foreach key $keys { set log($key) "[table lookup -subtable "[IP::client_addr]:[TCP::client_port]" "$key"]" } set log(tcp_time) "[expr {[clock clicks -milliseconds] - $tcp_start_time}]" set log(event) CLIENT_CLOSED # http_time didn't get set, log here (HTTP_RESPONSE_RELEASE never called, catch redirects, aborted connections) if { not ([info exists log(http_time)]) } { if { [info exists http_request_time] } { # called HTTP_REQUEST but not HTTP_RESPONSE_RELEASE using HTTP 1.0 or 1.1 set log(http_time) "[expr {[clock clicks -milliseconds] - $http_request_time}]" } call hsllog $tcp_start_time log } elseif { $log(loglevel) > 1 } { call hsllog $tcp_start_time log } # clean out table when client disconnects table delete -subtable [IP::client_addr]:[TCP::client_port] -all }Set the SameSite Attribute for LTM Persistence Cookies
Problem this snippet solves: Chrome (and likely other browsers to follow) will enforce the SameSite attribute on HTTP cookies to Lax beginning soon (initial limited rollout week of Feb 17th, 2020) which could impact sites that don't explicitly set the attribute. This iRule will add the SameSite attribute to LTM persistence cookies. Contributed by: hoolio How to use this snippet: Apply the iRule to the appropriate virtual servers. Code : when HTTP_RESPONSE_RELEASE { # Log debug to /var/log/tlm? 1=yes, 0=no set persist_cookie_dbg 1 # Set the SameSite cookie attribute value to one of: Strict, Lax or None # # None: Cookies will be sent in both first-party context and cross-origin requests; # however, the value must be explicitly set to None and all browser requests must # follow the HTTPS protocol and include the Secure attribute which requires an encrypted # connection. Cookies that don't adhere to that requirement will be rejected. # Both attributes are required together. If just None is specified without Secure or # if the HTTPS protocol is not used, the third-party cookie will be rejected. # # Lax: Cookies will be sent automatically only in a first-party context and with HTTP GET requests. # SameSite cookies will be withheld on cross-site sub-requests, such as calls to load images or iframes, # but will be sent when a user navigates to the URL from an external site, e.g., by following a link. # # Strict: browser never sends cookies in requests to third party domains # # Above definitions from: https://docs.microsoft.com/en-us/microsoftteams/platform/resources/samesite-cookie-update set samesite_security "none" # Exit this rule if the VS does not have a persist cookie profile attached if {not [PROFILE::exists persist cookie]}{ if {$persist_cookie_dbg}{log local0. "[IP::client_addr]:[TCP::client_port]: Exiting because there isn't a cookie persist profile on the VS"} return } # Get the persistence cookie profile cookie name # [PROFILE::persist mode cookie cookie_name] returns: # - a runtime error, if a persist profile isn't defined on the VS # - a null length string, if the cookie persist profile doesn't have a cookie name set (which is the default) # - the cookie name, if the cookie persist profile has a custom cookie name set if {[set persist_cookie [PROFILE::persist mode cookie cookie_name]] ne ""}{ # Above command returned a custom cookie name from the persistence profile if {$persist_cookie_dbg}{log local0. "[IP::client_addr]:[TCP::client_port]: \$persist_cookie=$persist_cookie"} } else { # Cookie persist profile does not have a custom cookie name set, so derive it from the pool name, using the format BIGipServer set persist_cookie "BIGipServer[LB::server pool]" } if {$persist_cookie_dbg}{log local0. "[IP::client_addr]:[TCP::client_port]: Parsed persist cookie name=$persist_cookie"} # Set the samesite cookie attribute on the persistence cookie switch [string tolower $samesite_security] { "none" { # samesite=none requires the Secure flag also be set HTTP::cookie attribute $persist_cookie insert "SameSite" "None" HTTP::cookie secure $persist_cookie } "lax" - "strict" { HTTP::cookie attribute $persist_cookie insert "SameSite" $samesite_security } default { if {$persist_cookie_dbg}{log local0. "[IP::client_addr]:[TCP::client_port]: Invalid SameSite attribute value ''. \ Needs to be one of None|Lax|Strict"} } } # Log the Set-Cookie header values if {$persist_cookie_dbg}{log local0. "[IP::client_addr]:[TCP::client_port]: Set-Cookie header values=[HTTP::header values {set-cookie}]"} } # Log examples: # No cookie persist profile enabled on the virtual server: : 10.1.1.8:51193: Exiting because there isn't a cookie persist profile on the VS # Default cookie persist profile enabled on the virtual server (no persist cookie name is explicitly defined) : 10.1.1.8:51215: Parsed persist cookie name=BIGipServer/Common/http_pool : 10.1.1.8:51215: Set-Cookie header values={BIGipServerhttp_pool=117506314.20480.0000; path=/; Httponly; Secure} # Custom cookie persist profile enabled on the virtual server with a custom cookie name defined as "my_persist_cookie" : 10.1.1.8:51255: $persist_cookie=my_persist_cookie : 10.1.1.8:51255: Parsed persist cookie name=my_persist_cookie : 10.1.1.8:51255: Set-Cookie header values={my_persist_cookie=117506314.20480.0000; path=/; Httponly; Secure;SameSite=None} Tested this on version: 13.0
iRules Development Environment
Problem this snippet solves: You want to write iRules on your own system and save them into some source control repo (git) then you need some tools. You could look at the old and out of date iRules Editor but want you really want is something more powerful. You want an IDE!! You need VSCode (Visual Studio Code) How to use this snippet: How to setup VSCode for iRule development Download and install VSCode, if you are on Windows system recommend the User Installer over the System Installer Once installed you will need some Extensions, click on the Extensions icon on the and search for the following extensions or click on the links below to open the VisualStudio Marketplace where you can click on the Install button. Recommended Extensions: f5-networks-iRule GitLens Tcl or TCL Better Comments You can now open up a folder and create some files and write some iRules. VSCode help (https://code.visualstudio.com/docs) Git help (http://think-like-a-git.net/) For a central Git repo recommand GitHub or GitLab Code : Example iRule file named logTime.tcl: ltm rule logTime { when CLIENT_ACCEPTED { set timeInMilliseconds [clock clicks -milliseconds] log local0.info "TCP connection started at [clock format [expr {$timeInMilliseconds / 1000}] -format "%H:%M:%S" -gmt true].[format {%03u} [expr {$timeInMilliseconds % 1000}]] for IP [IP::client_addr]" } when HTTP_REQUEST { set timeInMilliseconds [clock clicks -milliseconds] log local0.info "HTTP Reqest at [clock format [expr {$timeInMilliseconds / 1000}] -format "%H:%M:%S" -gmt true].[format {%03u} [expr {$timeInMilliseconds % 1000}]] for IP [IP::client_addr] and URI [HTTP::uri]" } } Tested this on version: No Version Found
Proxy Protocol v2 Initiator
Problem this snippet solves: Proxy Protocol v1 related articles have already been posted on DevCentral, but there is no v2 support iRule code available. A customer wanted to support Proxy Protocol v2, so I wrote an iRule code for supporting v2. Proxy protocol for the BIG-IP (f5.com) How to use this snippet: Back-end server must handle Proxy header prior data exchange. Code : when CLIENT_ACCEPTED { # DEBUG On/Off set DEBUG 0 set v2_proxy_header "0d0a0d0a000d0a515549540a" # v2 version and command : 0x21 - version 2 & PROXY command set v2_ver_command "21" # v2 address family and transport protocol : 0x11 - AF_INET (IPv4) & TCP protocol set v2_af_tp "11" # v2 Address Size : 0x000C - 12 bytes for IPv4 + TCP set v2_address_length "000c" # Get TCP port - 2 byte hexadecimal format set src_port [format "%04x" [TCP::client_port]] set dst_port [format "%04x" [TCP::local_port]] # Get Src Address and convert to 4 byte hexadecimal format foreach val [split [IP::client_addr] "."] { append src_addr [format "%02x" $val] } # Get Dst Address and convert to 4 byte hexadecimal format foreach val [split [IP::local_addr] "."] { append dst_addr [format "%02x" $val] } # Build proxy v2 data set proxy_data [binary format H* "${v2_proxy_header}${v2_ver_command}${v2_af_tp}${v2_address_length}${src_addr}${dst_addr}${src_port}${dst_port}"] if { $DEBUG } { binary scan $proxy_data H* proxy_dump log local0. "[IP::client_addr]:[TCP::client_port]_[IP::local_addr]:[TCP::local_port] - proxy_data dump : $proxy_dump" } } when SERVER_CONNECTED { TCP::respond $proxy_data }
