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Seida

Seida is a Symbolic Execution plugin for IDA.

Seida is C/S architecture:

the server is responsible for providing the symbolic execution of the simulation environment.
the client as IDA plugin.

Server

Before we can use the client-side plugin, we need to start the server first. For now we use angr as execution engine, we can replace it with any other engine later.

Create venv and install angr:

$ python -m venv venv
$ source venv/bin/activate
$ pip install angr

then we can start Seida Server inside venv:

$ python server.py init_script
SEIDA_SERVER_ADDR = "http://0.0.0.0:50052"
>

You also can input some simple python code in this server console(It's the same environment as the client side), e.g.:

> print(project.arch)
<Arch AARCH64 (LE)>

If you want write some complex code, you can write them in a script file and use load command to load it:

> load init_script

NOTE: you also can use python server.py init_script to launch the server, it will auto load init_script at beginning.

Install

Before install plugin, you need to change SEIDA_SERVER_ADDR in serda.py first.

and then:

As Script: use File / Script file... in IDA to load serda.py .
As Plugin: change SEIDA_USE_AS_SCRIPT to False, and then put serda.py in the IDA/plugins folder.

Usage

When the plugin is installed, the following buttons will be added to the IDA toolbar:

[start], start symbolic simulation execution from the current position.
[step], step one instruction
[stepb], step one basic block
[stept], step to cursor position

Command

In addition to these buttons, Seida also provide some python commands, you can use them in IDA's Python console.

Load File

Before you can do anything, you need to load the file same as the current loaded by IDA.

$ seida.load(filepath, base_addr=0)

NOTE: If your server and client are not on the same machine, the filepath file is the file on the server, not on the client.

Dump Memory

$ seida.dump_memory(addr, size)
7fffffffffed870  f8 ff ff ff ff ff ff ff  ff ff ff ff 00 00 00 00  |................|
7fffffffffed880  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
7fffffffffed890  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
7fffffffffed8a0  e8 ff ff ff ff ff ff ff  00 00 00 00 00 00 00 00  |................|
7fffffffffed8b0  f0 ff fe ff ff ff ff 07  4c 1b f2 00 00 00 00 00  |........L.......|
7fffffffffed8c0

Set Register

$ seida.set_reg(reg_name, val)

Hook Function

$ seida.hook_func(func_addr)

Run Script

Write a python script file:

x = claripy.BVS('x', 8 * 8)  # symbolic heap memory
simulation.active[0].memory.store(0x00102c98, x, size=8)

NOTE: For more information about symbolic execution, please go to angr.

and then load this script:

$ seida.do_file(py_file_path)