feat: add https payload interception via ssl bumping

[Copilot]

Investigated whether Squid proxy can intercept HTTPS payloads for debugging. Answer: yes, via SSL bumping.

Changes

Core Implementation

• CLI: Added --ssl-bump flag with security warnings
• Configuration: Extended SquidConfig to generate ssl_bump directives for HTTPS interception
• Certificate: Auto-generate ephemeral CA certificate via generate-cert.sh on container startup
• Container: Updated Squid Dockerfile to install OpenSSL

Visibility Enhancement

Without SSL bumping (default):

172.30.0.20 api.github.com:443 CONNECT 200 TCP_TUNNEL api.github.com:443

With SSL bumping:

172.30.0.20 api.github.com GET 200 TCP_MISS https://api.github.com/zen "curl/7.81.0"

Full URL path, HTTP method, and headers now visible in logs.

Configuration Logic

Generates different Squid configs based on mode:

• Default: http_port 3128 with CONNECT tunneling
• SSL bump: https_port 3128 intercept ssl-bump with peek/bump/terminate directives

Intelligently references ACLs based on domain type (plain/patterns/both).

Security

• Opt-in only (disabled by default)
• Ephemeral certificates (auto-generated, not persisted)
• Prominent warnings on execution
• Comprehensive security documentation

Testing

• 11 new test cases covering SSL bumping configuration
• All scenarios: plain domains, wildcard patterns, combinations
• 359 total tests passing

Usage

sudo awf --allow-domains github.com --ssl-bump -- curl -k https://api.github.com/zen

Note: -k required as ephemeral CA not trusted by default. Feature intended for debugging only.

Original prompt

Investigate if the Squid proxy container can intercept the HTTPS payload as a logging / debugging mechanism

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