Bypassing TLS Certificate Validation with Ld_preload
13 hours ago
- #Linux
- #Security Research
- #TLS
- Introduces tls-preloader, a tool to bypass TLS certificate validation on Linux using LD_PRELOAD.
- Supports multiple TLS libraries including OpenSSL, GnuTLS, NSS, mbedTLS, and wolfSSL.
- Useful for security research, debugging embedded systems, and analyzing network traffic.
- Explains the dynamic linking process in Linux and how LD_PRELOAD intercepts function calls.
- Details technical implementation, including intercepted functions and debugging with LD_DEBUG.
- Lists practical applications like security assessments, IoT device analysis, and development testing.
- Covers installation and example commands for using the tool with applications like curl and Firefox.
- Discusses limitations, including incompatibility with statically linked binaries and certain languages.
- Explains why LD_PRELOAD doesn't work with sudo due to security restrictions (AT_SECURE).
- Provides a case study demonstrating the tool's effectiveness with Firefox and BadSSL.com.