GLORP

Glorp is an HTTP intercept proxy, allowing the inspection and replaying of HTTP requests. The layout and flow was designed to function similar to Portswigger's Burp Proxy and Repeater tabs. The proxy functionality is done using Google's Martian, UI is done with TView.

The idea is to provide a CLI based tool for when you wanna-look-at-this-thing-real-quick and not fire up yet another full-fat container/vm/whatever with Burp and so forth.

Install

Install can be done with git clone and go build/install, or by using one of the binaries available on the releases page.

If you'd like to patch the net/http header casing problems, you can enable the included overlay to overwrite the relevant part of net/http. Note, this has been tested on go1.22.0 on Linux:

go build -overlay overlay.json

Alternatively, to run under docker, clone this repository and:

docker build -tglorp .
docker run -p 8080:8080 --rm -it glorp

Command Line Flags

Usage of ./glorp:
  -addr string
    	The bind address, default 0.0.0.0
  -cert string
    	Path to a CA Certificate
  -help
    	Show help
  -key string
    	Path to the CA cert's private key
  -port uint
    	Listen port for the proxy, default 8080
  -proxy string
    	downstream proxy to use in URI format. example: socks5://127.0.0.1:9050. empty means no downstream proxy
  -v int
    	log level

Using a custom CA

You'll probably want to specify a CA file, so you can load this into your browser/mobile device/operating system/whatever. The easiest way to spin up your own CA for use in Glorp is as follows:

openssl genrsa -out ca.key 2048
openssl req -x509 -new -nodes -key ca.key -sha256 -days 1825 -out ca.crt -subj '/CN=GlorpCA'

Remember to set a common-name. Without a common-name, some platforms like iOS don't play nice. Then, launch glorp:

doi@buzdovan:~/go/src/glorp$ ./glorp -cert ca.crt -key ca.key

UI Usage

Key	View	Details
tab	All	Go to next element (window, button, etc) in the page
shift+tab	All	Go to previous element in the page
ctrl-c	All	Exit Glorp
ctrl-n	All	Go the next page
ctrl-p	All	Go to the previous page
ctrl-r	Proxy/Replay	Send item to the replayer
ctrl-s	Proxy/Replay - highlighted request/response	Save item to file
g	Proxy	Go to first entry in the proxy table
G	Proxy	Go to last entry in the proxy table
/	Proxy	Enter a search-filter regex to filter proxy entries by URL
ctrl-e	Proxy - highlighted request/response	Open the request/response data in view
ctrl-b	Replay	Create a new blank replay item - useful for assembling requests from scratch
ctrl-d	Replay	Delete replay item
ctrl-e	Replay - highlighted request/response	Edit request in vi, responses will open with view
ctrl-x	Replay	Rename replay item
ctrl-g	Replay	Send the request

Ctrl-N and Ctrl-P cycle between the different pages, Tab/Shift+tab is used to cycle between each item within a page.

Proxy Page

The proxy page shows incoming requests. If you select the last item (bottom item), then the view will follow new requests.

Sitemap Page

The sitemap shows the various URLs and hosts that have been accessed via the proxy. You can navigate the list and hit enter to drill down further. This only shows URLs and does not support request/response data in the sitemap view yet.

Replay Page

In the proxy page, hit ctrl-r on an entry and it will be sent to the replay page, where you can modify the request and re-issue it. If you hit ctrl-r in the Replay page, it'll duplicated the current item.

The replays support a history of your sent data. As you modify requests and send them, the history will grow. You can go back and view the previous requests. Editing a previous request that has a response will automatically create a new history entry so you don't lose your old request data.

Editing

Highlight the request text box and hit ctrl-e. This will open the request in VI and let you edit it.

Pro-tip for content length: If you highlight your modified request body in visual mode (v) and then hit g->ctrl+g it will show you how many bytes are selected, and you can update the content-length header accordingly.

Sending Requests

The current replay request can be sent by either hitting the Go button or using ctrl-g.

If the AutoSend checkbox is selected, then after the request is edited it will be automatically sent.

Using an external editor

The highlight->ctrl-e->edit in VI->exit VI->send flow is admittedly clunky, so Glorp also supports using an external editor. If you enable the Ext. Editor check box, the request is spooled out to a temporary file. Any edits to this file are picked up by Glorp. This can be combined with auto-send and auto-content-length updating.

Note: The temp file is removed when Ext. Editor is unchecked. If you do not uncheck this, Glorp will not clean up the temp file for you.

Enabling Ext. Editor should show you the filename to edit:

You can then open that file with any editor and changes will auto-load into Glorp:

You can have multiple external editors open; however, only the one currently focused in glorp will auto-send.

Log Page

This is the general log info page and takes no user input. Glorp is set up such that any call to log.Println or similar will end up in this view.

Save/Load Page

This one should hopefully be self explanatory. Lets you save and load all the proxy entries and replay entries. Writes out to a JSON file or reads in a JSON file. WARNING: Loading will delete all existing proxy and replay entries, rather than append to them.

Transparent Proxying

Glorp does not support transparent proxying, but squid does :D Rather than build this logic into Glorp, I figure run a squid proxy and forward it through. The squid config should look like:

acl all src 0.0.0.0/0
http_access allow all

http_port 3128 
http_port 3080 intercept
https_port 3443 ssl-bump intercept \
  cert=<PATH TO KEY AND CERT IN ONE PEM> \
  generate-host-certificates=on dynamic_cert_mem_cache_size=4MB

sslcrtd_program /usr/local/squid/libexec/security_file_certgen -s /var/lib/ssl_db -M 4MB
acl step1 at_step SslBump1
ssl_bump peek step1
ssl_bump bump all

# forward to glorp
cache_peer 127.0.0.1 parent 8080 0 no-query default
never_direct allow all
sslproxy_cert_error allow all
sslproxy_flags DONT_VERIFY_PEER
sslproxy_cert_error allow all
sslproxy_flags DONT_VERIFY_PEER

Use iptables to hijack the connection:

iptables -t nat -A PREROUTING -i enp1s0 -p tcp --dport 80 -j REDIRECT --to-port 3080
iptables -t nat -A PREROUTING -i enp1s0 -p tcp --dport 443 -j REDIRECT --to-port 3443
iptables -t nat -A POSTROUTING -o enp1s0 -j MASQUERADE

Squid can be built with the following dockerfile:

# docker run --net=host -it --rm -v $PWD:/etc/squid sq1 /usr/local/squid/sbin/squid -N -f /etc/squid/squid.conf
# Net host saves some docker iptables headaches, should probably document how to do that properly...
FROM debian:latest

WORKDIR /opt/

RUN apt update 
RUN apt upgrade -y
RUN apt install -y automake libtool build-essential libssl-dev git ca-certificates

## clone and build squid
RUN git clone https://github.com/squid-cache/squid && cd squid && autoreconf -i
RUN cd /opt/squid && ./configure --prefix=/usr/local/squid --with-openssl --enable-ssl-crtd
RUN cd /opt/squid && make -j4 && make install

# sort the log file dir perms and create the ssl junk
RUN chown nobody /usr/local/squid/var/logs/
RUN /usr/local/squid/libexec/security_file_certgen -c -s /var/lib/ssl_db -M 4MB