pappyproxy 0.2.6

The Pappy Intercepting Proxy

The Pappy Proxy

Introduction

The Pappy (Proxy Attack Proxy ProxY) Proxy is an intercepting proxy for performing web application security testing. Its features are often similar, or straight up rippoffs from Burp Suite. However, Burp Suite is neither open source nor a command line tool, thus making a proxy like Pappy inevitable. The project is still in its early stages, so there are bugs and only the bare minimum features, but it should be able to do some cool stuff soon (I’m already using it for real work).

Contributing

I am taking any and all feature requests. If you’ve used Burp and had any inconvenience with it, tell me about it and I’ll do everything in my power to make sure Pappy doesn’t have those issues. Or even better, if you want Burp to do something that it doesn’t already, let me know so that I can [STRIKEOUT:use it to stomp them into the dust] improve my project.

If you’re brave and want to try and contribute code, please let me know. Right now the codebase is kind of rough and I have refactored it a few times already, but I would be more than happy to find a stable part of the codebase that you can contribute to.

How to Use It

Installation

Pappy supports OS X and Linux (sorry Windows). Installation requires pip or some other command that can handle a setup.py with requirements. Once the requirements are installed, you can check that it installed correctly by running pappy -l to start the proxy.

$ git clone --recursive https://github.com/roglew/pappy-proxy.git
$ cd pappy-proxy
$ pip install .

Quickstart

Pappy projects take up an entire directory. Any generated scripts, exported responses, etc. will be placed in the current directory so it’s good to give your project a directory of its own. To start a project, do something like:

$ mkdir test_project
$ cd test_project
$ pappy
Copying default config to directory
Proxy is listening on port 8000
pappy> exit
$ ls
data.db      project_config.json
$

And that’s it! The proxy will by default be running on port 8000 and bound to localhost (to keep the hackers out). You can modify the port/interface in config.json. You can list all your intercepted requests with ls, view a full request with vfq <reqid> or view a full response with vfs <reqid>. Right now, the only command to delete requests is filter_prune which deletes all the requests that aren’t in the current context (look at the sections on the context/filter strings for more information on that).

Lite Mode

If you don’t want to dirty up a directory, you can run Pappy in “lite” mode. Pappy will use the default configuration settings and will create a temporary data file in /tmp to use. When you quit, the file will be deleted. If you want to run Pappy in lite mode, run Pappy with either -l or --lite.

Example:

$ pappy -l
Temporary datafile is /tmp/tmpw4mGv2
Proxy is listening on port 8000
pappy> quit
Deleting temporary datafile
$

Adding The CA Cert to Your Browser

In order for Pappy to view data sent using HTTPS, you need to add a generated CA cert (certificate.crt) to your browser. Certificates are generated using the gencerts command and are by default stored in ~/.pappy/certs. This allows Pappy to act as a CA and sign any HTTPS certificate it wants without the browser complaining. This allows Pappy to decrypt and modify HTTPS requests. The certificate installation instructions are different for each browser.

Firefox

You can add the CA cert to Firefox by going to Preferences -> Advanced -> View Certificates -> Authorities -> Import and selecting the certificate.crt file in the certs directory.

Chrome

You can add the CA cert to Chrome by going to Settings -> Show advanced settings -> HTTPS/SSL -> Manage Certificates -> Authorities -> Import and selecting the certificate.crt file in the certs directory.

Safari

For Safari (on macs, obviously), you need to add the CA cert to your system keychain. You can do this by double clicking on the CA cert and following the prompts.

Internet Explorer

I didn’t search too hard for instructions on this (since Pappy doesn’t support windows) and I don’t own a Windows machine to try this, so if you have trouble, I’m not the one to ask. According to Google you can double-click the cert to install it to the system, or you can do Tools -> Content -> Certificates -> Trusted Root Certificates -> Import.

Configuration

Configuration for each project is done in the config.json file. The file is a JSON-formatted dictionary that contains settings for the proxy. The following fields can be used to configure the proxy:

Key	Value
data_file	The file where requests and images will be stored
debug_dir (optional)	Where connection debug info should be stored. If not present, debug info is not saved to a file.
cert_dir	Where the CA cert and the private key for the CA cert are stored
proxy_listeners	A list of dicts which describe which ports the proxy will listen on. Each item is a dict with “port” and “interface” values which determine which port and interface to listen on. For example, if port=8000 and the interface is 127.0.0.1, the proxy will only accept connections from localhost on port 8000. To accept connections from anywhere, set the interface to 0.0.0.0.

The following tokens will also be replaced with values:

Token	Replaced with
{DATADIR}	The directory where Pappy’s data files are stored

See the default config.json for examples.

Generating Pappy’s CA Cert

In order to intercept and modify requests to sites that use HTTPS, you have to generate and install CA certs to your browser. You can do this by running the gencerts command in Pappy. By default, certs are stored ~/.pappy/certs. This is also the default location that Pappy will look for certificates (unless you specify otherwise in config.json.) In addition, you can give the gencerts command an argument to have it put the generated certs in a different directory.

Command	Description
gencerts [/path/to/put/certs/in]	Generate a CA cert that can be added to your browser to let Pappy decrypt HTTPS traffic. Also generates the private key for that cert in the same directory. If no path is given, the certs will be placed in the default certificate location. Overwrites any existing certs.

Browsing Recorded Requests/Responses

The following commands can be used to view requests and responses

Command	Aliases	Description
ls [a|<num>]	list, ls	List requests that are in the current context (see Context section). Has information like the host, target path, and status code. With no arguments, it will print the 25 most recent requests in the current context. If you pass ‘a’ or ‘all’ as an argument, it will print all the requests in the current context. If you pass a number “n” as an argument, it will print the n most recent requests in the current context.
sm	sm, site_map	Print a tree showing the site map. It will display all requests in the current context that did not have a 404 response.
viq <id(s)>	view_request_info, viq	View additional information about requests. Includes the target port, if SSL was used, applied tags, and other information.
vfq <id(s)>	view_full_request, vfq	[V]iew [F]ull Re[Q]uest, prints the full request including headers and data.
vhq <id(s)>	view_request_headers, vhq	[V]iew [H]eaders of a Re[Q]uest. Prints just the headers of a request.
vfs <id(s)>	view_full_response, vfs	[V]iew [F]ull Re[S]ponse, prints the full response associated with a request including headers and data.
vhs <id(s)>	view_response_headers, vhs	[V]iew [H]eaders of a Re[S]ponse. Prints just the headers of a response associated with a request.

The table shown by ls will have the following columns:

Label	Description
ID	The request ID of that request. Used to identify the request for other commands.
Method	The method(/http verb) for the request
Host	The host that the request was sent to
Path	The path of the request
S-Code	The status code of the response
Req Len	The length of the data submitted
Rsp Len	The length of the data returned in the response
Time	The time in seconds it took to complete the request
Mngl	If the request or response were mangled with the interceptor. If the request was mangled, the column will show ‘q’. If the response was mangled, the column will show ‘s’. If both were mangled, it will show ‘q/s’.

Tags

You can apply tags to a request and use filters to view specific tags. The following commands can be used to apply and remove tags to requests:

Command	Aliases	Description
tag <tag> [id(s)]	tag	Apply a tag to the given requests. If no IDs are given, the tag will be applied to all in-context requests.
untag <tag> [id(s)]	untag	Remove a tag from the given ids. If no IDs are given, the tag is removed from every in-context request.
clrtag <id(s)>	clrtag	Removes all tags from the given ids.

Request IDs

Request IDs are how you identify a request and every command that involves specifying a request will take one or more request IDs. You can see it when you run ls. In addition, you can prepend an ID with prefixes to get requests or responses associated with the request (for example if you modified the request or its response with the interceptor, you can get the unmangled versions.) Here are the valid prefixes:

Prefix	Description
u	If the request was mangled, prefixing the ID with u will result in the unmangled version of the request. The resulting request will not have an associated response because it was never submitted to the server.
s	If the response was mangled, prefixing the request ID s will result in the same request but its associated response will be the unmangled version.

I know it sounds kind of unintuitive. Here are some example commands that will hopefully make things clearer. Suppose request 1 had its request mangled, and request 2 had its response mangled.

• vfq 1 Prints the mangled version of request 1

• vfq u1 Prints the unmangled version of request 1

• rp u1 Open the repeater with the unmangled version of request 1

• vfs u1 Throws an error because the unmangled version was never submitted

• vfs s1 Throws an error because the response for request 1 was never mangled

• vfs 2 Prints the mangled response of request 2

• vfs s2 Prints the unmangled response of request 2

• vfq u2 Throws an error because request 2’s request was never mangled

• vfs u2 Throws an error because request 2’s request was never mangled

Passing Multiple Request IDs to a Command

Some arguments can take multiple IDs for an argument. To pass multiple IDs to a command, separate the IDs with commas (no spaces!). A few examples:

• viq 1,2,u3 View information about requests 1, 2, and the unmangled version of 3

• gma foo 4,5,6 Generate a macro with definitions for requests 4, 5, and 6

Context

The context is a set of filters that define which requests are considered “active”. Only requests in the current context are displayed with ls. By default, the context includes every single request that passes through the proxy. You can limit down the current context by applying filters. Filters apply rules such as “the response code must equal 500” or “the host must contain google.com”. Once you apply one or more filters, only requests/responses which pass every active filter will be a part of the current context.

Command	Aliases	Description
f <filter string>	filter, fl, f	Add a filter that limits which requests are included in the current context. See the Filter String section for how to create a filter string
fc	filter_clear, fc	Clears the filters and resets the context to contain all requests and responses. Ignores scope
fu	filter_up, fu	Removes the most recently applied filter
fls	filter_list, fls	Print the filters that make up the current context
filter_prune	filter_prune	Delete all the requests that aren’t in the current context from the data file

Filter Strings

Filter strings define a condition that a request/response pair must pass to be part of the context. Most filter strings have the following format:

<field> <comparer> <value>

Where <field> is some part of the request/response, <comparer> is some comparison to <value>. For example, if you wanted a filter that only matches requests to target.org, you could use the following filter string:

host is target.org

field = "host"
comparer = "is"
value = "target.org"

Also if you prefix a comparer with ‘n’ it turns it into a negation. Using the previous example, the following will match any request except for ones where the host contains target.org:

host nis target.org

field = "host"
comparer = "nis"
value = "target.org"

For fields that are a list of key/value pairs (headers, get params, post params, and cookies) you can use the following format:

<field> <comparer1> <value1>[ <comparer2> <value2>]

This is a little more complicated. If you don’t give comparer2/value2, the filter will pass any pair where the key or the value matches comparer1 and value1. If you do give comparer2/value2, the key must match comparer1/value1 and the value must match comparer2/value2 For example:

Filter A:
    cookie contains Session

Filter B:
    cookie contains Session contains 456

Filter C:
    cookie ncontains Ultra

Cookie: SuperSession=abc123
Matches A and C but not B

Cookie: UltraSession=abc123456
Matches both A and B but not C

List of fields

Field Name	Aliases	Description	Format
all	all	The entire request represented as one string	String
host	host, domain, hs, dm	The target host (ie www.target.com)	String
path	path, pt	The path of the url (ie /path/to/secrets.php)	String
body	body, data, bd, dt	The body (data section) of either the request or the response	String
verb	verb, vb	The HTTP verb of the request (ie GET, POST)	String
param	param, pm	Either the get or post parameters	Key/Value
header	header, hd	An HTTP header (ie User-Agent, Basic-Authorization) in the request or response	Key/Value
rawheaders	rawheaders, rh	The entire header section (as one string) of either the head or the response	String
sentcookie	sentcookie, sck	A cookie sent in a request	Key/Value
setcookie	setcookie, stck	A cookie set by a response	Key/Value
statuscode	statuscode, sc, responsecode	The response code of the response	Numeric
tag	tag	Any of the tags applied to the request	String

List of comparers

Field Name	Aliases	Description
is	is	Exact string match
contains	contains, ct	A contain B is true if B is a substring of A
containsr	containsr, ctr	A containr B is true if A matches regexp B
exists	exists, ex	A exists B if A is not an empty string (likely buggy)
Leq	Leq	A Leq B if A’s length equals B (B must be a number)
Lgt	Lgt	A Lgt B if A’s length is greater than B (B must be a number )
Llt	Llt	A Llt B if A’s length is less than B (B must be a number)
eq	eq	A eq B if A = B (A and B must be a number)
gt	gt	A gt B if A > B (A and B must be a number)
lt	lt	A lt B if A < B (A and B must be a number)

Special form filters

A few filters don’t conform to the field, comparer, value format. You can still negate these.

Format	Aliases	Description
before	before, bf, b4	Filters out any request that is not before the given request. Filters out any request without a time.
after	after, af	Filters out any request that is not before the given request. Filters out any request without a time.

Scope

Scope is a set of rules to define whether Pappy should mess with a request. You define the scope by setting the context to what you want the scope to be and running scope_save. The scope is saved in the data file and is automatically restored when using the same project directory.

Any requests which don’t match all the filters in the scope will be passed straight to the browser and will not be caught by the interceptor or recorded in the data file. This is useful to make sure you don’t accidentally do something like log in to your email through the proxy and have your plaintext username/password stored.

Command	Aliases	Description
scope_save	scope_save	Set the current context to be the scope
sr	scope_reset, sr	Set the current context to the scope
scope_delete	scope_delete	Clear the scope (everything’s in scope!)
scope_list	scope_list, sls	List all the filters that are applied to the scope

Built-In Filters

Pappy also includes some built in filters that you can apply. These are things that you may want to filter by but may be too tedius to type out. The fbi command also supports tab completion.

Filter	Description
not_image	Matches anything that isn’t an image.
not_jscss	Matches anything that isn’t JavaScript or CSS.

Command	Aliases	Description
fbi <filter>	builtin_filter, fbi	Apply a built-in filter to the current context

Interceptor

This feature is like Burp’s proxy with “Intercept Mode” turned on, except it’s not turned on unless you explicitly turn it on. When the proxy gets a request while in intercept mode, it lets you edit it before forwarding it to the server. In addition, it can stop responses from the server and let you edit them before they get forwarded to the browser. When you run the command, you can pass req and/or rsp as arguments to say whether you would like to intercept requests and/or responses. Only in-scope requests/responses will be intercepted (see Scope section).

The interceptor will use your EDITOR variable to decide which editor to edit the request/response with. If no editor variable is set, it will default to vi.

To forward a request, edit it, save the file, then quit.

Command	Aliases	Description
ic <req,rsp>+	intercept, ic	Begins interception mode. Press enter to leave interception mode and return to the command prompt. Pass in request to intercept requests, response to intercept responses, or both to intercept both.

Intercept both requests and responses:
> ic requests responses
> ic req rsp

Intercept just requests:
> ic requests
> ic req

Intercept just responses:
> ic responses
> ic rsp

Be totally useless:
> ic

To drop a request, delete everything, save and quit.

Repeater

This feature is like Burp’s repeater (yes, really). You choose a request and Pappy will open vim in a split window with your request on the left and the original response on the right. You can make changes to the request and then run “:RepeaterSubmitBuffer” to submit the modified request. The response will be displayed on the right. This command is bound to <leader>f by default, but you can bind it to something else too in your vimrc (I think, dunno if vim will complain if the function undefined which it will be for regular files). This command will submit whatever buffer your cursor is in, so make sure it’s in the request buffer.

When you’re done with repeater, run “:qa!” to avoid having to save changes to nonexistent files.

Command	Aliases	Description
rp <id>	repeater, rp	Open the specified request in the repeater

Vim Command	Keybinding	Action
RepeaterSubmitBuffer	f	Submit the current buffer, split the windows vertically, and show the result in the right window

Macros

Macros are Pappy’s version of Burp’s intruder. You can use macros to make automated requests through the proxy and save them to the data file. A macro file is any python script file in the current directory that is in the form macro_<name>.py. An example project directory with macros would be:

$ ls -l
-rw-r--r-- 1 scaryhacker wheel     150 Nov 26 11:17 config.json
-rw------- 1 scaryhacker wheel 2639872 Nov 26 17:18 data.db
-rw-r--r-- 1 scaryhacker wheel     471 Nov 26 18:42 macro_blank.py
-rw-r--r-- 1 scaryhacker wheel     264 Nov 26 18:49 macro_hackthensa.py
-rw-r--r-- 1 scaryhacker wheel    1261 Nov 26 18:37 macro_testgen.py
-rw-r--r-- 1 scaryhacker wheel     241 Nov 26 17:18 macro_test.py

In this case we have a blank, hackthensa, testgen, and test macro. A macro script is any python script that defines a run_macro(args) function and a MACRO_NAME variable. For example, a simple macro would be:

--- macro_print.py

MACRO_NAME = 'Print Macro'

def run_macro(args):
    if args:
        print "Hello, %s!" % args[0]
    else:
        print "Hello, Pappy!"

You can place this macro in your project directory then load and run it from Pappy. When a macro is run, arguments are passed from the command line. Arguments are separated the same way as they are on the command line, so if you want to use spaces in your argument, you have to put quotes around it.

$ pappy
Proxy is listening on port 8000
pappy> lma
Loaded "<Macro Test Macro (tm/test)>"
Loaded "<Macro Macro 6494496 (testgen)>"
Loaded "<Macro Print Macro (print)>"
Loaded "<Macro Hack the NSA (htnsa/hackthensa)>"
Loaded "<Macro Macro 62449408 (blank)>"
pappy> rma print
Hello, Pappy!
pappy> rma print NSA
Hello, NSA!
pappy> rma print Idiot Slayer
Hello, Idiot!
pappy> rma print "Idiot Slayer"
Hello, Idiot Slayer!

You’ll need to run lma every time you make a change to the macro in order to reload it. In addition, any code outside of the run_macro function will be run when it the macro gets loaded.

Generating Macros From Requests

You can also generate macros that have Pappy Request objects created with the same information as requests you’ve already made. For example:

$ pappy
Proxy is listening on port 8000
pappy> ls
ID  Verb  Host         Path               S-Code  Req Len  Rsp Len  Time  Mngl
5   GET   vitaly.sexy  /esr1.jpg          200 OK  0        17653    --    --
4   GET   vitaly.sexy  /netscape.gif      200 OK  0        1135     --    --
3   GET   vitaly.sexy  /construction.gif  200 OK  0        28366    --    --
2   GET   vitaly.sexy  /vitaly2.jpg       200 OK  0        2034003  --    --
1   GET   vitaly.sexy  /                  200 OK  0        1201     --    --
pappy> gma sexy 1
Wrote script to macro_sexy.py
pappy> quit
$ cat macro_sexy.py
from pappyproxy.http import Request, get_request, post_request

MACRO_NAME = 'Macro 94664581'
SHORT_NAME = ''

###########
## Requests

req0 = Request((
'GET / HTTP/1.1\r\n'
'Host: vitaly.sexy\r\n'
'User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:36.0) Gecko/20100101 Firefox/36.0\r\n'
'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\n'
'Accept-Language: en-US,en;q=0.5\r\n'
'Accept-Encoding: gzip, deflate\r\n'
'Connection: keep-alive\r\n'
'Pragma: no-cache\r\n'
'Cache-Control: no-cache\r\n'
'\r\n'
))


def run_macro(args):
    # Example:
    # req = req0.copy() # Copy req0
    # req.submit() # Submit the request to get a response
    # print req.response.raw_headers # print the response headers
    # req.save() # save the request to the data file
    # or copy req0 into a loop and use string substitution to automate requests
    pass

If you enter in a value for SHORT_NAME, you can use it as a shortcut to run that macro. So if in a macro you set SHORT_NAME='tm' you can run it by running pappy> rma tm.

Command	Aliases	Description
lma [dir]	load_macros, lma	Load macros from a directory. If dir is not given, use the current directory (the project directory)
rma <macro name>	run_macro, rma	Run a macro with the given name. You can use the shortname, filename, or long name.
gma <name> [id(s)]	generate_macro, gma	Generate a macro with the given name. If request IDs are given, the macro will contain request objects that contain each request.
rpy <id(s)>	rpy	Print the Python object definitions for each of the given ids

Request Objects

The main method of interacting with the proxy is through Request objects. You can submit a request with req.sumbit() and save it to the data file with req.save(). The objects also have attributes which can be used to modify the request in a high-level way. Unfortunately, I haven’t gotten around to writing full docs on the API and it’s still changing every once in a while so I apologize if I pull the carpet out from underneath you.

Dict-like objects are represented with a custom class called a RepeatableDict. I haven’t gotten around to writing docs on it yet, so just interact with it like a dict and don’t be surprised if it’s missing some methods you would expect a dict to have.

Here is a quick list of attributes that you can use with Request objects:

Attribute	Settable?	Data Type	Description
cookies	Yes	RepeatableDict	Cookies sent in the request
fragment	Yes	String	The url fragment (The text after the #)
full_path	No	String	The path including url params and the fragment
full_request	No	String	The full request including headers and data
headers	Yes	RepeatableDict	The headers of the request
host	Yes	String	The host that the request is sent to
is_ssl	Yes	Bool	Whether the request is/was sent over SSL
path	Yes	String	The document path (ie www.a.com/this/is/the/path)
port	Yes	Integer	The port the request is/was sent to
post_params	Yes	RepeatableDict	Post parameters
raw_data	Yes	String	The data part of the request
raw_headers	No	String	The text of the headers section of the request
reqid	Yes	Integer	The ID of the request. If set when save() is called, it replaces the request with the same id in the database
response	Yes	Response	The associated response for the request
rsptime	No	Datetime Delta	The time it took to complete the request. Set when submit() is called
status_line	Yes	String	The status line of the request (ie ‘GET / HTTP/1.1’)
time_end	Yes	Datetime	The time when the request was completed
time_start	Yes	Datetime	The time when the request was started
unmangled	Yes	Request	If the request was mangled, the unmangled version of the request
url	Yes	String	The URL of the request (ie ‘https://www.google.com’)
url_params	Yes	RepeatableDict	The URL parameters of the request
verb	Yes	String	The verb used for the request (ie GET, POST, PATCH, HEAD, etc). Doesn’t have to be a valid verb.
version	Yes	String	The version part of the status line (ie ‘HTTP/1.1’)

Request methods:

Function	Description
submit()	Submit the request through the proxy. Does not save the request to the data file
save()	Save the request, its unmangled version, its associated response, and the unmangled version of the response to the database

And here is a quick list of attributes that you can use with Response objects:

Attribute	Settable?	Data Type	Description
cookies	Yes	RepeatableDict	Cookies set by the response
headers	Yes	RepeatableDict	The headers of the response
response_code	Yes	Integer	The response code of the response
response_text	Yes	String	The text associated with the response code (ie OK, NOT FOUND)
rspid	Yes	Integer	The response id of the response. If this is the same as another response in the database, calling save() on the associated request will replace that response in the database
unmangled	Yes	Response	If the response was mangled, this will refer to the unmangled version of the response. Otherwise it is None
version	Yes	String	The version part of the status line of the response (ie ‘HTTP/1.1’)
raw_headers	No	String	A text version of the headers of the response
status_line	Yes	String	The status line of the response
raw_data	Yes	String	The data portion of the response
full_response	No	String	The full text version of the response including headers and data

Like I said, these interfaces are prone to change and will probably crash when you use them. If you get a traceback, send me an email so I can fix it.

Useful Functions

There are also a few functions which could be useful for creating requests in macros. It’s worth pointing out that request_by_id is useful for passing request objects as arguments. For example, here is a macro that lets you resubmit a request with the Google Bot user agent:

## macro_googlebot.py

from pappyproxy.http import Request, get_request, post_request, request_by_id
from pappyproxy.context import set_tag
from pappyproxy.iter import *

MACRO_NAME = 'Submit as Google'
SHORT_NAME = ''

def run_macro(args):
    req = request_by_id(args[0])
    req.headers['User-Agent'] = "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
    req.submit()
    req.save()

Function	Description
get_request(url, url_params={})	Returns a Request object that contains a GET request to the given url with the given url params
post_request(url, post_params={}, url_params={})	Returns a Request object that contains a POST request to the given url with the given url and post params
request_by_id(reqid)	Get a request object from its id.

Intercepting Macros

Intercepting macros let you mangle requests as they pass through the proxy. Similarly to normal macros, an intercepting macro is any python script with an “int” prefix. For example, int_name.py would be a valid intercepting macro name. They are also loaded with the lma command. An intercepting macro can define two functions: mangle_request or mangle_response. Both requests only take a Request object as a parameter. mangle_request returns either a new, modified Request object to change it, or it can return the original object to not mangle it. The mange_response must return a Response (not request!) object. The request passed in to mangle_response will have an associated response with it. If you want to modify the response, copy request.response, make modifications, then return it. If you would like to pass it through untouched, just return request.response.

Note, that due to twisted funkyness, you cannot save requests from intercepting macros. Technically you can, but to do that you’ll have to define async_mangle_request (or response) instead of mangle_request (or response) then use Request.async_deep_save which generates a deferred, then generate a deferred from async_mangle_requests (inline callbacks work too). If you’ve never used twisted before, please don’t try. Twisted is hard. Plus the mangled request will be saved before it is submitted anyways.

Confusing? Here are some example intercepting macros:

## int_cloud2butt.py

import string

MACRO_NAME = 'Cloud to Butt'

def mangle_response(request):
    r = request.response.copy()
    r.raw_data = string.replace(r.raw_data, 'cloud', 'butt')
    r.raw_data = string.replace(r.raw_data, 'Cloud', 'Butt')
    return r

## int_donothing.py

import string

MACRO_NAME = 'Do Nothing'

def mangle_request(request):
    return request

def mangle_response(request):
    return request.response

## int_adminplz.py

from base64 import base64encode as b64e

MACRO_NAME = 'Admin Session'

def mangle_request(request):
    r = request.copy()
    r.headers['Authorization'] = 'Basic %s' % b64e('Admin:Password123')
    return r

In addition, you can use an init(args) function to get arguments from the command line. If no arguments are passed, args will be an empty list. Here is an example macro that does a search and replace:

## int_replace.py

MACRO_NAME = 'Find and Replace'
SHORT_NAME = ''
runargs = []

def init(args):
    global runargs
    runargs = args

def mangle_request(request):
    global runargs
    if len(runargs) < 2:
        return request
    request.body = request.body.replace(runargs[0], runargs[1])
    return request

def mangle_response(request):
    global runargs
    if len(runargs) < 2:
        return request.response
    request.response.body = request.response.body.replace(runargs[0], runargs[1])
    return request.response

You can use this macro to do any search and replace that you want. For example, if you wanted to replace “Google” with “Skynet”, you can run the macro like this:

pappy> lma
Loaded "<InterceptingMacro Find and Replace (replace)>"
pappy> rim replace Google Skynet
"Find and Replace" started
pappy>

Now every site that you visit will be a little bit more accurate.

Enabling/Disabling Intercepting Macros

You can use the following commands to start/stop intercepting macros

Command	Aliases	Description
lma [dir]	load_macros, lma	Load macros from a directory. If dir is not given, use the current directory (the project directory)
rim <macro name>	run_int_macro, rim	Run an intercepting macro. Similarly to normal macros you can use the name, short name, or file name of the macro.
sim <macro name> [args]	stop_int_macro, sim	Stop an intercepting macro. If arguments are given, they will be passed to the macro’s init(args) function if it exists.
lim	list_int_macros, lsim	List all enabled/disabled intercepting macros
gima <name>	generate_int_macro, gima	Generate an intercepting macro with the given name.

Logging

You can watch in real-time what requests are going through the proxy. Verbosisty defaults to 1 which just states when connections are made/lost and some information on what is happening. If verbosity is set to 3, it includes all the data which is sent through the proxy and processed. It will print the raw response from the server, what it decodes it to, etc. Even if you don’t run this command, all the information is stored in the dubug directory (the directory is cleared every start though!)

Command	Description
log [verbosity]	View the log at the given verbosity. Default verbosity is 1 which just shows connections being made/lost and some other info, verbosity 3 shows full requests/responses as they pass through and are processed by the proxy

Additional Commands and Features

This is a list of other random stuff you can do that isn’t categorized under anything else. These are mostly commands that I found that I needed while doing a test and just added. They likely don’t do a ton of error checking.

Command	Aliases	Description
dump_response <reqid> [filename]	dump_response	Dumps the data from the response to the given filename (useful for images, .swf, etc). If no filename is given, it uses the name given in the path.
export <req|rsp> <reqid>	export	Writes either the full request or response to a file in the current directory.

Response streaming

If you don’t have any intercepting macros running, Pappy will forward data to the browser as it gets it. However, if you’re trying to mangle messages/responses, Pappy will need to download the entire message first.

FAQ

Why does my request have an id of --?!?!

You can’t do anything with a request/response until it is decoded and saved to disk. In between the time when a request is decoded and when it’s saved to disk, it will have an ID of --. So just wait a little bit and it will get an ID you can use.

Changelog

The boring part of the readme

• 0.1.2

• Refactor almost every part of proxy

• Basic framework for plugins

• Bugfixes probably

• Create changelog

• 0.1.1

• Start using sane versioning system

• No idea what I added