irule
677 Topics- tcl logic in SAML Attribute value field possible?Hi. We're running BigIP as a SAML IDP. Can I somehow issue tcl logic in a SAML attributes? I'm talking about the Access ›› Federation : SAML Identity Provider : Local IdP Services, editing an object, under SAML Attributes. Based on what's in the memberOf attribute, I need to issue as a value either empty string or "SpecificValue". I am familiar with the %{session.variable} construct, but I don't want to clutter the session with more variables if I can avoid it, as that impacts all sessions using our IDP (30 or so federated services on the same VIP and AP). I tried these two approches: %{ set result {} ; if { [mcget {session.ad.last.attr.memberOf}] contains {| CN=SpecificGroup,OU=Resource groups,OU=Groups,DC=Domain,DC=com |}} { set result {SpecificValue} } ; return $result } expr { set result {} ; if { [mcget {session.ad.last.attr.memberOf}] contains {| CN=SpecificGroup,OU=Resource groups,OU=Groups,DC=Domain,DC=com |}} { set result {SpecificValue} } ; return $result } Expected result: An issued claim with the value "" or "SpecificValue" Actual result: An issued claim with the above code as the value As I mentioned, we've set it up using one VIP that is hosting 30 or so services. We're running 16.1.3.1. They are using the same SSO configuration and there's an iRule triggerd at ACCESS_POLICY_AGENT_EVENT, which does some magic to extract issuer and suchlike, and that helps to make decisions later in the Access Policy. It also populates a few session variables under the session.custom namespace for use in the Access Policy. Additional session variables are being populated in the Access Policy, such as resolved manager and their email address. I have looked briefly at the ASSERT::saml functions, but even if it would be possible to manipulate that way, I wish to keep this set up as stream lined as possible and with as few new "special cases" in an iRule. So while I appreciate pointers along that route as well, I would first of all like to know if there is a way to do it natively in the SAML attribute value field. And if there are any options I have not yet explored here?1.1KViews0likes6Comments
- F5 iRule for X-Country-Code not working as expectedIs it possible to insert an X-Country-Code into the F5 BIG-IP response to the client. I want to do this only for a specific URI pattern. I tried the iRule below, using HTTP_REQUEST to capture the country code when the pattern /java is matched and substituting it in the HTTP_RESPONSE, but it didn't work. Any suggestions would be greatly appreciated. HTTP_REQUEST { if {[HTTP::uri] starts_with "/java"} { set country_code [whereis [IP::client_addr] country] log local0. "Matched /example - client IP: [IP::client_addr], country: $country_code" # Temporarily store country code in a header for use in HTTP_RESPONSE HTTP::header insert "X-Country-Temp" $country_code } } when HTTP_RESPONSE { if {[HTTP::uri] starts_with "/java"} { log local0. "HTTP_RESPONSE triggered for [IP::client_addr]" HTTP::header insert "X-Country-Code" "$country_code" log local0. "Added X-Country-Code: $country_code to response" } } Also I tried below in the response , but no luck when HTTP_RESPONSE { if {[HTTP::header exists "X-Country-Code" ]} { log local0. "HTTP_RESPONSE triggered for [IP::client_addr]" HTTP::header insert "X-Country-Code" "$country_code" log local0. "Added X-Country-Code: $country_code to response" } }Solved109Views0likes4Comments
- Is it possible to select ASM BoT profile from irule?Hi. . Is it possible to select BoT profile from irule? . Concept is we have different set of IP which need to allow "some" BoT type. That why we can't use whitelist IP in BoT profile because it will allow all BoT type. So We want to use iRule to check if it IP A > use BoT profile which have some exception, but if all other IP > use normally BoT profile. . when HTTP_REQUEST { # Check IP and select BoT profile from that if { [IP::client_addr] eq "A" } { ASM::enable allow_some_bot_profile } else { ASM::enable normally_bot_profile } } ps. I didn't see any document about how to select BoT profile. So I'm not sure if ASM::enable can do that.78Views0likes3Comments
- Best approach to serve maintenance pageHi, We need to put website under maintenance for about 6 hours. Traffic flow: Clients -->Akamai--->F5-->Backend servers. We have maintenance page hosted in AWS cloud Front. which approach is better? DNS Change – Temporarily point our domain (via CNAME) to CloudFront by adjusting the TTL to 2 minutes. F5 Configuration – Issue a 302 redirect from F5 to CloudFront or forward (reverse proxy) traffic from F5 to CloudFront by modifying the Host header. This keeps the browser on our domain and returns a 200 OK. Main concerns : Avoiding browser/edge caching issues (we can clear Akamai cache if needed). Ensuring a quick rollback after maintenance. Which approach would be best? Could you advise on the correct implementation?121Views0likes4Comments
- Trigger js challenge/Captcha for ip reputation/ip intelligence categoriesProblem solved by this Code Snippet Because some ISP or cloud providers do not monitor their users a lot of times client ip addresses are marked as "spam sources" or "windows exploits" and as the ip addresses are dynamic and after time a legitimate user can use this ip addresses the categories are often stopped in the IP intelligence profile or under the ASM/AWAF policy. This usually happens in Public Clouds that do not monitor what their users do and the IP gets marked as bad then another good user after a day or two has this ip address and this causes the issue. For many of my clients I had to stop the ip reputation/ip intelligence category "spam sources" and in some cases "windows exploits" so having a javascript/captcha checks seems a nice compromise 😎 To still make use of this categories the users coming from those ip addresses can be forced to solve captcha checks or at least to be checked for javascript support! How to use this Code Snippet Have AWAF/ASM and ip intelligence licensed Add AWAF/ASM policy with irule support option (by default not enabled under the policy) or/and Bot profile under the Virtual server Optionally add IP intelligence profile or enable the Ip intelligence under the WAF policy without the categories that cause a lot of false positives, Add the irule and if needed modify the categories for which it triggers Do not forget to first create the data group, used in the code or delete that part of the code and to uncomment the Bot part of the code, if you plan to do js check and not captcha and maybe comment the captcha part ! Code Snippet Meta Information Version: 17.1.3 Coding Language: TCL Code You can find the code and further documentation in my GitHub repository: reputation-javascript-captcha-challlenge/ at main · Nikoolayy1/reputation-javascript-captcha-challlenge when HTTP_REQUEST { # Take the ip address for ip reputation/intelligence check from the XFF header if it comes from the whitelisted source ip addresses in data group "client_ip_class" if { [HTTP::header exists "X-Forwarded-For"] && [class match [IP::client_addr] equals "/Common/client_ip_class"] } { set trueIP [HTTP::header "X-Forwarded-For"] } else { set trueIP [IP::client_addr] } # Check if IP reputation is triggered and it is containing "Spam Sources" if { ([llength [IP::reputation $trueIP]] != 0) && ([IP::reputation $trueIP] contains "Spam Sources") }{ log local0. "The category is [IP::reputation $trueIP] from [IP::client_addr]" # Set the variable 1 or bulean true as to trigger ASM captcha or bot defense javascript set js_ch 1 } else { set js_ch 0 } # Custom response page just for testing if there is no real backend origin server for testing if {!$js_ch} { HTTP::respond 200 content { <html> <head> <title>Apology Page</title> </head> <body> We are sorry, but the site you are looking for is temporarily out of service<br> If you feel you have reached this page in error, please try again. </body> </html> } } } # when BOTDEFENSE_ACTION { # Trigger bot defense action javascript check for Spam Sources # if {$js_ch && (not ([BOTDEFENSE::reason] starts_with "passed browser challenge")) && ([BOTDEFENSE::action] eq "allow") }{ # BOTDEFENSE::action browser_challenge # } # } when ASM_REQUEST_DONE { # Trigger ASM captcha check only for users comming from Spam sources that have not already passed the captcha check (don't have the captcha cookie) if {$js_ch && [ASM::captcha_status] ne "correct"} { set res [ASM::captcha] if {$res ne "ok"} { log local0. "Cannot send captcha_challenge: \"$res\"" } } } Extra References: BOTDEFENSE::action ASM::captcha ASM::captcha_status293Views1like1Comment
- Json parsing with iRulesJSON is now the format of choice for most APIs. It's time we were able to parse JSON with F5 iRules too, as simple string matching is not always good enough. That's why I wrote a simple JSON parser for iRules. It is a validating single pass parser that processes the JSON string char by char until the JsonPath expression matches, no recursion or any other fancy stuff. As I do not wanted to reinvent the wheel, it is basically a rewrite of the JSON parser found in the mongoose webserver project in plain TCL. The usage is very simple: set token [call json::json_get_tok { $json $path }] $json is the json string to parse $path is a JsonPath expression, following operators are implemented: Operator Description $ The root element to query. This starts all path expressions. .<name> Dot-notated child. [<number>] Array index. Example Simple JSON: { "aud": "audience \"test\"", "iss": "https://issuer.de/issuer/", "iat": 1701422123, "roles": [ "role1", "role2" ], "obj": { "sub": "adcad2b8", }, "ver": "2.0" } JsonPath expression to parse this simple JSON: JsonPath Return value $.aud "audience \"test\"" $.iat 1701422123 $.obj.sub "adcad2b8" $.roles[0] "role1" To decode the extracted JSON string: set decoded [call json::json_decode_str { $token }] This removes the enclosing quotes from a string and decodes JSON escapes. Code You can find the code and further documentation in my GitHub repository: https://github.com/JuergenMang/f5-irules-json965Views3likes2Comments
- irule to block a non valid urlHi, we send web traffic to our F5 APM, this traffic is analyzed by an Elasticsearch server Sometimes our APM receives an invalid http request that causes problems on our Elasticsearch server. The URL contains a lot of special characters Is there any idea for a rule to block such invalid requests? correct xxxx TECH_REQUEST w.x.y.z:42426 CONNECT vcsa.vmware.com:443 1 Internet_SrvUpdates 708b5c79 (ALLOWED_WILDCARD) incorrect xxxx TECH_REQUEST w.x.y.z :52900 ��_ ��[� ��+��>�©L��^'�9����&�,�+�$�#� 1 Internet_SrvUpdates 708b5c79 (BLOCKED_NO_WILDCARD_OR_TUPLE) many thanks80Views0likes2Comments