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eCapture(旁观者): capture SSL/TLS text content without CA cert Using eBPF.

Note

Supports Linux/Android kernel versions x86_64 4.18 and above, aarch64 5.5 and above. Does not support Windows and macOS system.

How eCapture works

SSL/TLS plaintext capture, support openssl\libressl\boringssl\gnutls\nspr(nss) libraries.
GoTLS plaintext support go tls library, which refers to encrypted communication in https/tls programs written in the golang language.
bash audit, capture bash command for Host Security Audit.
mysql query SQL audit, support mysqld 5.6\5.7\8.0, and mariadDB.

eCapture Architecture

eCapture User Manual

Getting started

use ELF binary file

Download ELF zip file release , unzip and use by command ./ecapture --help.

Linux kernel version >= 4.18 is required.
Enable BTF BPF Type Format (BTF) (Optional, 2022-04-17)

Command line options

Note

Need ROOT permission.

eCapture search /etc/ld.so.conf file default, to search load directories of SO file, and search openssl shard libraries location. or you can use --libssl flag to set shard library path.

If target program is compile statically, you can set program path as --libssl flag value directly。

Pcapng result

./ecapture tls -i eth0 -w pcapng -p 443 capture plaintext packets save as pcapng file, use Wireshark read it directly.

plaintext result

./ecapture tls will capture all plaintext context ,output to console, and capture Master Secret of openssl TLS save to ecapture_masterkey.log. You can also use tcpdump to capture raw packet,and use Wireshark to read them with Master Secret settings.

check your server BTF config：

cfc4n@vm-server:~$# uname -r
4.18.0-305.3.1.el8.x86_64
cfc4n@vm-server:~$# cat /boot/config-`uname -r` | grep CONFIG_DEBUG_INFO_BTF
CONFIG_DEBUG_INFO_BTF=y

tls command

capture tls text context. Step 1:

./ecapture tls --hex

Step 2:

curl https://github.com

libressl&boringssl

# for installed libressl, libssl.so.52 is the dynamic ssl lib
vm@vm-server:~$ ldd /usr/local/bin/openssl
	linux-vdso.so.1 (0x00007ffc82985000)
	libssl.so.52 => /usr/local/lib/libssl.so.52 (0x00007f1730f9f000)
	libcrypto.so.49 => /usr/local/lib/libcrypto.so.49 (0x00007f1730d8a000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f1730b62000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f17310b2000)

# use the libssl to config the libssl.so path
vm@vm-server:~$ sudo ./ecapture tls --libssl="/usr/local/lib/libssl.so.52" --hex

# in another terminal, use the command, then type some string, watch the output of ecapture
vm@vm-server:~$ /usr/local/bin/openssl s_client -connect github.com:443

# for installed boringssl, usage is the same
/path/to/bin/bssl s_client -connect github.com:443

bash command

capture bash command.

ps -ef | grep foo

What's eBPF

eBPF

How to compile

Linux Kernel: >= 4.18.

Tools

golang 1.18 or newer
clang 9.0 or newer
cmake 3.18.4 or newer
clang backend: llvm 9.0 or newer
kernel config:CONFIG_DEBUG_INFO_BTF=y (Optional, 2022-04-17)

command

ubuntu

If you are using Ubuntu 20.04 or later versions, you can use a single command to complete the initialization of the compilation environment.

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/gojue/ecapture/master/builder/init_env.sh)"

other Linux

In addition to the software listed in the 'Toolchain Version' section above, the following software is also required for the compilation environment. Please install it yourself.

linux-tools-common
linux-tools-generic
pkgconf
libelf-dev

Clone the repository code and compile it

git clone git@github.com:gojue/ecapture.git
cd ecapture
make
bin/ecapture

compile without BTF

eCapture support BTF disabled with command make nocore to compile at 2022/04/17. It can work normally even on Linux systems that do not support BTF.

make nocore
bin/ecapture --help

Contributing

See CONTRIBUTING for details on submitting patches and the contribution workflow.

askk / ecapture