LDAP StartTLS Extension to LDAPS Proxy
Problem this snippet solves: The outlined iRule implements a LDAP StartTLS-Extension (see RFC2830) to traditional LDAPS proxy. The iRule can be used to add StartTLS-Extension support to LDAP instances, which do not support the StartTLS extension. The iRule will inspect the first TCP datagram for the LDAP-StartTLS request OID. If a StartTLS request is identified, the iRule will parse the ASN.1/BER structure of the LDAP request to extract the LDAP MessageID. Once the MessageID is extracted, the iRule will respond on behalf of the LDAP server with a LDAP response containing the request MessageID and StartTLS OID and then forward the remaining server side connection to a traditional LDAPS pool. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_ACCEPTED>: Client 172.21.92.28%1 is Connected to VS 172.21.17.211%1:389 Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_ACCEPTED>: Starting to collect LDAP TCP data. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Received LDAP TCP data. Searching for LDAP STARTTLS request OID. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Parsing 1st BER encoded message envelope (type and length). Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Checking 1st BER encoded message type = sequence (0x30). Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: 1st BER encoded message type is sequence (0x30). Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Checking if 1st BER encoded length value is a Multi-Byte length field. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Multi-Byte length field detected. Parsing the Multi-Byte length field value. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Adding the Multi-Byte length to scan offset. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Parsing 2nd BER encoded message envelope (type and length). Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Checking 2nd BER encoded message type = integer (0x02) Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: 1st BER encoded message type is integer (0x02). Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Checking if 1st BER encoded length value is a Multi-Byte length field. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Extracting 2nd BER encoded message value = MessageId. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Sending STARTTLS reply with matching LDAP MessageID to client. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Selecting LDAPS:683 pool. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Clearing the collected payload buffer. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Unset temporary array variable. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <CLIENT_DATA>: Releasing the connection. Mon Feb 29 09:41:42 CET 2016 debug f5-02 tmm1[2649] Rule /Common/LDAP_STARTTLS <SERVER_CONNECTED>: Client 172.21.92.28%1 is forwarded to 172.21.91.20%1:636 Cheers, Kai How to use this snippet: Usage: Create a new iRule and copy/paste the provided iRule into it. Modify the $static::ldaps_pool variable to match your LDAPS:636 pool name. Attach the iRule to your LDAP:386 Vitual Server. Test the iRule with an StartTLS aware LDAP client pointing to the LDAP:386 Vitual Server. Code : when RULE_INIT { set static::ldaps_pool "INSERT_YOUR_LDAPS_POOL_NAME" array set static::hex_filler { 1 "0000000" 2 "000000" 3 "00000" 4 "0000" 5 "000" 6 "00" 7 "0" 8 "" } } when CLIENT_ACCEPTED { log local0.debug "Client [IP::client_addr] is Connected to VS [IP::local_addr]:[TCP::local_port]" # log local0.debug "Starting to collect LDAP TCP data." TCP::collect } when CLIENT_DATA { # log local0.debug "Received LDAP TCP data. Searching for LDAP STARTTLS request OID." if { [TCP::payload] contains "1.3.6.1.4.1.1466.20037" } then { if { [catch { # log local0.debug "Parsing 1st BER encoded message envelope (type and length)." binary scan [TCP::payload] H2c temp(ber_1_type) temp(ber_1_length) set temp(scan_offset) 2 # log local0.debug "Checking 1st BER encoded message type = sequence (0x30)." if { $temp(ber_1_type) eq "30" } then { # log local0.debug "1st BER encoded message type is sequence (0x30)." # log local0.debug "Checking if 1st BER encoded length value is a Multi-Byte length field." if { [expr { $temp(ber_1_length) & 0x80 }] } then { # log local0.debug "Multi-Byte length field detected. Parsing the Multi-Byte length field value." # Diabled: binary scan [TCP::payload] x$temp(scan_offset)H[expr { ($temp(ber_1_length) & 0x7F) * 2 }] temp(ber_1_mlength) # log local0.debug "Adding the Multi-Byte length to scan offset." incr temp(scan_offset) [expr { $temp(ber_1_length) & 0x7F }] # Diabled: log local0.debug "Formating the received HEX string to numeric value." # Diabled: set temp(ber_1_length) [expr { [subst "0x$temp(ber_1_mlength)"] }] } # Diabled: log local0.debug "Extracting 1nd BER encoded message value = XXX." # Diabled: binary scan [TCP::payload] x$temp(scan_offset)H[expr { $temp(ber_2_length) * 2 }] temp(ber_2_value) # log local0.debug "Parsing 2nd BER encoded message envelope (type and length)." binary scan [TCP::payload] x$temp(scan_offset)H2c temp(ber_2_type) temp(ber_2_length) incr temp(scan_offset) 2 # log local0.debug "Checking 2nd BER encoded message type = integer (0x02)" if { $temp(ber_2_type) eq "02" } then { # log local0.debug "1st BER encoded message type is integer (0x02)." # log local0.debug "Checking if 1st BER encoded length value is a Multi-Byte length field." if { [expr { $temp(ber_2_length) & 0x80 }] } then { # log local0.debug "Multi-Byte length field detected. Parsing the Multi-Byte length field value." binary scan [TCP::payload] x$temp(scan_offset)H[expr { ($temp(ber_2_length) & 0x7F) * 2 }] temp(ber_2_mlength) # log local0.debug "Adding the Multi-Byte length to scan offset." incr temp(scan_offset) [expr { $temp(ber_2_length) & 0x7F }] # log local0.debug "Formating the received HEX string to numeric value." set temp(ber_2_length) [expr { [subst "0x$temp(ber_2_mlength)"] }] } # log local0.debug "Extracting 2nd BER encoded message value = MessageId." binary scan [TCP::payload] x$temp(scan_offset)H[expr { $temp(ber_2_length) * 2 }] temp(ber_2_value) # log local0.debug "Sending STARTTLS reply with matching LDAP MessageID to client." TCP::respond [binary format H* "30840000002B0204$static::hex_filler([string length $temp(ber_2_value)])$temp(ber_2_value)78840000001f0a0100040004008a16312e332e362e312e342e312e313436362e3230303337"] # log local0.debug "Selecting LDAPS:683 pool $static::ldaps_pool." pool $static::ldaps_pool # log local0.debug "Clearing the collected payload buffer." TCP::payload replace 0 [TCP::payload length] "" } } }]} then { log local0.debug "Parsing of BER encoded message envelope raised an error." log local0.debug "Extended ErrorInfo = [subst "\$::errorInfo"]" } # log local0.debug "Unset temporary array variable." unset -nocomplain temp } # log local0.debug "Releasing the connection." TCP::release } when SERVER_CONNECTED { log local0.debug "Client [IP::client_addr] is forwarded to [LB::server addr]:[LB::server port]" } Tested this on version: 12.0
SMTP iRule and Submission Port
Hi I'm trying to deploy smtp service on F5 and POPs, IMAPs and SMTPs (TCP 25) works fine. I just got stuck with submission port on TCP 587. Can not use STARTTLS extension. There is an irule [1] which is suppose to be cure same problem with SMTPs. Looks like people use that iRule and solved the "STARTTLS" issue. Can anyone confirm this irule whether works with submission port as well ? [1] https://devcentral.f5.com/codeshare?sid=700
