eCapture is a tool to capture SSL/TLS text content without CA cert Using eBPF.

How eCapture works

• SSL/TLS text context capture, support openssl\libressl\boringssl\gnutls\nspr(nss) libraries.
• bash audit, capture bash command for Host Security Audit.
• mysql query SQL audit, support mysqld 5.6\5.7\8.0, and mariadDB.

eCapture Architecure

Getting started

use ELF binary file

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

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

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

uprobe HOOK

openssl\libressl\boringssl hook

eCapture hookSSL_write \ SSL_read function of shared library /lib/x86_64-linux-gnu/libssl.so.1.1. get text context, and send message to user space by eBPF maps.

Probes: []manager.Probe{ { Section: “uprobe/SSL_write”, EbpfFuncName: “probe_entry_SSL_write”, AttachToFuncName: “SSL_write”, //UprobeOffset: 0x386B0, BinaryPath: “/lib/x86_64-linux-gnu/libssl.so.1.1”, }, { Section: “uretprobe/SSL_write”, EbpfFuncName: “probe_ret_SSL_write”, AttachToFuncName: “SSL_write”, //UprobeOffset: 0x386B0, BinaryPath: “/lib/x86_64-linux-gnu/libssl.so.1.1”, }, { Section: “uprobe/SSL_read”, EbpfFuncName: “probe_entry_SSL_read”, AttachToFuncName: “SSL_read”, //UprobeOffset: 0x38380, BinaryPath: “/lib/x86_64-linux-gnu/libssl.so.1.1”, }, { Section: “uretprobe/SSL_read”, EbpfFuncName: “probe_ret_SSL_read”, AttachToFuncName: “SSL_read”, //UprobeOffset: 0x38380, BinaryPath: “/lib/x86_64-linux-gnu/libssl.so.1.1”, }, /*/
},

bash readline.so hook

hook /bin/bash symbol name readline.

How to compile

Linux Kernel: >= 4.18.

Tools

• golang 1.16
• clang 9.0.0
• cmake 3.18.4
• clang backend: llvm 9.0.0
• kernel config:CONFIG_DEBUG_INFO_BTF=y (Optional, 2022-04-17)

command

git clone git@github.com:ehids/ecapture.git
cd ecapture
make
bin/ecapture –help

compile without BTF

eCapture support NO BTF with command make nocore to compile on 2022/04/17.

make nocore
bin/ecapture –help