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eCapture (旁观者): capture SSL/TLS text content without a CA certificate using eBPF.#

• Introduction
• Getting started
  • Download
    • ELF binary file
    • Docker image
  • Capture openssl text content.
  • Modules
    • OpenSSL Module
    • GoTLS Module
    • Other Modules
  • Videos
• Security & Operations
• Contributing
• Compilation

Introduction#

• 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.
• Zsh audit, capture zsh command for Host Security Audit.
• MySQL query SQL audit, support mysqld 5.6\5.7\8.0, and MariaDB.

Getting started#

Download#

ELF binary file#

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

Docker image#

# pull docker image
docker pull gojue/ecapture:latest
# run
docker run --rm --privileged=true --net=host -v ${HOST_PATH}:${CONTAINER_PATH} gojue/ecapture ARGS

⚠️ Security Note: --privileged=true grants full host access. For production use, consider specific capabilities instead. See Minimum Privileges Guide.

see Docker Hub for more information.

Capture openssl text content.#

sudo ecapture tls

eCapture will automatically detect the system's OpenSSL library and start capturing plaintext. When you make an HTTPS request (e.g., curl https://google.com), the captured request and response will be displayed:

...
INF module started successfully. moduleName=EBPFProbeOPENSSL
??? UUID:233851_233851_curl_5_1_172.16.71.1:51837, Name:HTTP2Request, Type:2, Length:304
header field ":method" = "GET"
header field ":path" = "/"
header field ":authority" = "google.com"
...

📄 For complete output examples, see docs/example-outputs.md.

Modules#

The eCapture tool comprises 8 modules that respectively support plaintext capture for TLS/SSL encryption libraries like OpenSSL, GnuTLS, NSPR, BoringSSL, and GoTLS. Additionally, it facilitates software audits for Bash, MySQL, and PostgreSQL applications.

• bash capture bash command
• zsh capture zsh command
• gnutls capture gnutls text content without CA cert for gnutls libraries.
• gotls Capturing plaintext communication from Golang programs encrypted with TLS/HTTPS.
• mysqld capture sql queries from mysqld 5.6/5.7/8.0 .
• nss capture nss/nspr encrypted text content without CA cert for nss/nspr libraries.
• postgres capture sql queries from postgres 10+.
• tls use to capture tls/ssl text content without CA cert. (Support openssl 1.0.x/1.1.x/3.0.x or newer).
  You can use ecapture -h to view the list of subcommands.

OpenSSL Module#

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。

The OpenSSL module supports three capture modes:

• pcap/pcapng mode stores captured plaintext data in pcap-NG format.
• keylog/key mode saves the TLS handshake keys to a file.
• text mode directly captures plaintext data, either outputting to a specified file or printing to the command line.

Pcap Mode#

Supported TLS encrypted http 1.0/1.1/2.0 over TCP, and http3 QUIC protocol over UDP.
You can specify -m pcap or -m pcapng and use it in conjunction with --pcapfile and -i parameters. The default value for --pcapfile is ecapture_openssl.pcapng.

sudo ecapture tls -m pcap -i eth0 --pcapfile=ecapture.pcapng tcp port 443

This command saves captured plaintext data packets as a pcapng file, which can be viewed using Wireshark.

📄 For complete pcapng mode output, see docs/example-outputs.md.

Keylog Mode#

You can specify -m keylog or -m key and use it in conjunction with the --keylogfile parameter, which defaults to ecapture_masterkey.log.

The captured OpenSSL TLS Master Secret information is saved to --keylogfile. You can also enable tcpdump packet capture and then use Wireshark to open the file and set the Master Secret path to view plaintext data packets.

sudo ecapture tls -m keylog -keylogfile=openssl_keylog.log

You can also directly use the tshark software for real-time decryption and display:

tshark -o tls.keylog_file:ecapture_masterkey.log -Y http -T fields -e http.file_data -f "port 443" -i eth0

Text Mode#

sudo ecapture tls -m text will output all plaintext data packets. (Starting from v0.7.0, it no longer captures
SSLKEYLOG information.)

GoTLS Module#

Similar to the OpenSSL module.

gotls command#

capture tls text context.

Step 1:

sudo ecapture gotls --elfpath=/home/cfc4n/go_https_client --hex

Step 2:

/home/cfc4n/go_https_client

more help#

sudo ecapture gotls -h

Other Modules#

such as bash\mysqld\postgres modules, you can use ecapture -h to view the list of subcommands.

Videos#

• Youtube video: How to use eCapture v0.1.0
• eCapture capturing plaintext of Golang TLS/HTTPS traffic

eCaptureQ GUI Application#

eCaptureQ is a cross-platform graphical user interface client for eCapture,
visualizing eBPF TLS capture
capabilities. Built using the Rust + Tauri + React technology stack, it provides a real-time, responsive interface,
enabling easy analysis of encrypted traffic without the need for CA certificates. It simplifies complex eBPF capture
techniques, making them easy to use. Supports two modes:

• Integrated Mode: Unified Linux/Android execution
• Remote Mode: Windows/macOS/Linux client connects to a remote eCapture service

Event Forwarding#

Event Forwarding Projects

Video Demonstration#

https://github.com/user-attachments/assets/c8b7a84d-58eb-4fdb-9843-f775c97bdbfb

🔗 GitHub Repository

Protobuf Protocols#

For details of the Protobuf log schema used by eCapture/eCaptureQ, see:

• protobuf/PROTOCOLS.md

Stargazers over time#

Security & Operations#

• Security Policy — Vulnerability reporting and supported versions
• Minimum Privileges — Required Linux capabilities and least-privilege configuration
• Defense & Detection — How to detect and defend against unauthorized usage
• Performance Benchmarks — Overhead measurement methodology and expected characteristics
• Release Verification — How to verify the integrity of release artifacts

Contributing#

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

Compilation#

Custom Compilation#

You can customize the features you want, such as setting the offset address for uprobe to support statically compiled OpenSSL libraries. Refer to the compilation guide for compilation instructions.

Configurations Remote Update#

After eCapture is running, you can dynamically modify the configurations through HTTP interfaces. Refer to the HTTP API Documentation.

Event Forwarding#

eCapture supports multiple event forwarding methods. You can forward events to packet capture software such as Burp Suite. For details, refer to the Event Forwarding API Documentation.