1 / 30

MuSL Builder

MuSL Builder. Handcrafting custom Mu Scenarios. MuSL in the Mu Scenario Editor. MuSL Builder Overview. MuSL _ Builder is a Ruby project that creates scenarios in the Mu Scenario Language (MuSL) Each MuSL_Builder component class creates protocol messages from text template files

aleron
Download Presentation

MuSL Builder

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. MuSL Builder Handcrafting custom Mu Scenarios

  2. MuSL in the Mu Scenario Editor

  3. MuSL Builder Overview • MuSL_Builder is a Ruby project that creates scenarios in the Mu Scenario Language (MuSL) • Each MuSL_Builder component class creates protocol messages from text template files • Messages are chained together to create a complete scenario

  4. High Level: The Builder UI

  5. Builder UI • The Builder UI puts together properties from the parameters and scenario steps dynamically created by the user • The Builder UI then builds the MuSL file using the MuslBuilder class

  6. The Power of MuSL_Builder • From a few message classes, it is easy to create a wide variety of scenarios • For example, to create a simple ‘ping’ flood, one would only need to use a single ICMP message class and a one-line statement in a MuSL_Builder properties file: messages=ICMPPing(100)

  7. A SIP Example • Given the sample SIP message templates, you could easily create a wacky scenario from properties files entries such as: sequence=wacky:SIPInvite(17),SIPPrack(3),SIPBye,SIPRegister(2),SIPAck,SIPBye,SIPTrying(12) messages=wacky(114) • A scenario created from this definition would contain 4,218 messages

  8. MuSL Builder Source Code • The project is located in mu-labs: • http://code.google.com/p/mu-labs/source/browse/trunk/analyzer/automation/MuSL_Builder • The project contains sample code for a variety of protocols, including SIP, IMAP, FTP, BGP and ICMP

  9. MuSL Builder Pieces • A complete set of MuSL Builder components includes: • The MuslBuilder class • the executable run from the command-line • A Base class • defines custom headers, options and variables • A Properties File • defines the scenario • Protocol Message Files • compose the scenario steps

  10. Base Classes • Each component implements its own Base class in order to customize the header with: • transports • options • variables • Base classes derive from a common base class which shares global fields among messages of the same component

  11. FTPBase with transport and options

  12. Message Files • There are two types of messages: • Client messages are sent to a Server • Server messages are sent to a Client • Each message file creates a complete protocol message in MuSL • Message files are simple .txt files containing messages in the Mu Scenario Language

  13. A Sample Message File # Request: USER anonymous FTP_Client_Send_<%= @step %> = <%= @transport %>.client_send { # ftp|File Transfer Protocol (FTP) "USER "$user"\\r\\n" } FTP_Server_Receive_<%= @step %> = FTP_Client_Send_<%= @step %>.server_receive

  14. Sample Message: Step • The ‘step’ is a unique identifier for each message pair, and is tracked globally • In the example template, the following line in the template: • SIP_Client_Send_<%= @step %> = • Is transformed at runtime, replacing <%= @step %> with the value of the global ‘step’ field. • The resulting line might look like this: • SIP_Client_Send_2 =

  15. Sample Message: Transport • Each message class has a default transport in its constructor • The default transport can be overridden by specification in the properties file: • messages=FTPMkdir[ALT_FTP_TRANSPORT] <%= @transport %>.client_send becomes ALT_FTP_TRANSPORT.client_send

  16. The MuslBuilder Class • muslbuilder.rb is the executable class • reads in a properties file or array • output a complete scenario in the Mu Scenario Language • The builder class creates a Hash (called ‘params’) from the properties which is passed into the Component base class constructor

  17. Properties • Properties can be in a text file or passed in to muslbuilder as an array, containing • options • sequences • Messages • components • additional transports • scenario_name • The properties are read by the muslbuilder (executable) and contain the blueprint for constructing the scenario • Properties files can have any name

  18. Properties: Parameters • Parameters are passed along to base class constructors, and typically contain global Scenario option or variable names and default values: • domain=mydomain.com • sender=joe_sender • recipient=joanna-recipient • The only required properties are “messages” and “components”, which defines the name of the protocol(s) to be used • components=FTP,HTTP

  19. Properties Files: Sequences • Sequences • Sequences are comma-separated lists of component message class names, in the format • sequence=sequence_name:Class1,Class2,Class3… • sequence=bye:SIPBye,SIPOk • A properties file can contain any number of user defined sequences • Sequences also provide a repeat syntax, which causes the specified message to be repeated as many times in a row as indicated • sequence=flood:SIPInvite(1000),SIPBye(12),SIPOk

  20. Properties Files: Messages • Messages are a comma-separated list containing any combination of message class and/or sequence names • There can be only one messages line per properties file messages=bye,SIPAck(12),flood,SIPRinging,SIPAck(2) • Using messages and sequences, all sorts of message patterns can be arbitrarily constructed

  21. Properties Files: Additional Transports • Sometimes you may want to add a transport later in the scenario. In the properties files, transports look similar to sequences: • transport=key:value • The transport can be added to a ‘sequence’ or put directly into ‘messages’. The transport can be used in any following step, using the alternate transport syntax • Musl_Builder changes the transport to a string in the form of “key = value” and inserts it into the scenario • Example: • transport=FTP_2:tcp(dst_port: 21) • messages=FTPReady,FTPUser,FTP_2,FTPGoodbye[FTP_2] • FTP_2 = tcp(dst_port: 21)

  22. Building a Scenario • From the command-line in the root directory, invoke ruby specifying and a properties file name. ruby muslbuilder.rb properties/sip.properties • The resulting text is a complete scenario in the Mu Scenario Language

  23. Load the scenario into the MuSL Editor • Open the Mu Scenario Editor in pcapr.net • Copy and Paste your MuSL Builder scenario into the left pane • Any syntax errors will be caught and indicated by the editor • The right pane will show the actual hex or text output of the scenario

  24. Importing into Studio • In order to import your scenario into Studio from the Mu Scenario Editor, you must have first opened pcapr from the Mu • Click the ‘studio’ link above the right pane • The scenario will be imported into the Mu and opened in a new browser window

  25. Executing the Scenario • In Mu Studio, set your testbed appropriately and run the scenario as usual • Scenario -> Verify

  26. Customizing the Scenario • Assertions are placed in Component Server classes • Global options and variables are placed in Component Base classes • Captured variables are placed in Component Server classes

  27. Sample Assertions and Variables SIP_Client_Receive=SIP_Server_Send.client_receive { assertions { /SIP\/2.0 (\d+)/:1 == "200" } variables { @to_tag = /To:.*?tag=(\w+)/:1 } }

  28. Sample Global Options template = 'scenario(name: "SIP") { options { $domain="<%= @domain %>” $sender="<%= @sender %>" $recipient="<%= @recipient %>" } steps { SIP = udp(src_port: 5060, dst_port: 5060) } }'

  29. Sample Global Variables template ='scenario(name: "ICMP") { variables { @data = random_bytes(56) @id = random_integer(4096) } steps { ICMP = ip(protocol: 1) } }'

  30. MuslParser: From Pcap To MuslBuilder • MuslBuilder message classes can be built readily from existing pcaps • 1. import pcap into the MuSL Editor • 2. save the left-pane as a text file (e.g. “a.msl”) • 3. ruby musl_parser.rba.msl output_ • MuslParser splits the .msl file into individual message step text files, including the erb substitutions needed for step counters and transports • Use these as the template strings in your message class files • ** You will still need to edit the strings to • a) create unique struct names (if any) with <%= @step %> • b) insert your global options and variables

More Related