feat: Add SSH jump host (-J) infrastructure and CLI integration by inureyes · Pull Request #30 · lablup/bssh

inureyes · 2025-08-29T13:46:06Z

Summary

This PR implements the foundation for SSH jump host support with OpenSSH-compatible -J syntax, addressing issue #22.

Key Features Implemented

🏗️ Jump Host Parser: Robust parsing of OpenSSH ProxyJump format (user@host:port,user2@host2:port2)
- Supports single and multiple jump hosts
- IPv6 address handling with bracket notation
- Comprehensive input validation and error handling
🖥️ CLI Integration: Full -J option support with jump host specification parsing
- OpenSSH-compatible command-line syntax
- Integration with existing command structure (exec, ping, upload, download)
- Informative logging when jump hosts are detected
🔗 Connection Management: Infrastructure for jump host connection chains
- JumpHostChain for managing multi-hop connections
- Connection health monitoring and statistics
- Error handling with jump context information
🔧 SSH Client Extensions: Enhanced tokio_client with jump host capabilities
- Public session access for direct-tcpip channel operations
- Infrastructure for channel-based SSH connections

Implementation Status

✅ Jump host specification parsing with comprehensive tests
✅ CLI integration with -J option working
✅ Connection chain management structure
✅ All existing tests passing (99 tests + 17 new jump tests = 116 total)
🚧 Actual SSH tunneling through jump hosts (requires deeper russh integration)

Testing

Added 17 comprehensive unit tests:

Jump host parsing for all supported formats (IPv6, user@host:port, etc.)
Error handling for malformed specifications
Chain management and connection state tracking
CLI integration validation

Usage Examples

# Single jump host
bssh -J jump@bastion.example.com -H target@internal.server "uptime"

# Multiple jump hosts  
bssh -J "jump1@bastion1,jump2@bastion2" -C production "df -h"

# With IPv6
bssh -J "user@[::1]:2222" -H target.local "systemctl status"

Test Plan

All existing tests continue to pass
Jump host parser handles all OpenSSH formats correctly
CLI -J option recognized and parsed
Error handling for invalid specifications
IPv6 address support with brackets
Multi-hop jump host chain parsing
Integration with existing command structure

Future Work

The foundation is now in place for full jump host functionality. The next phase will implement the actual SSH tunneling through russh's direct-tcpip channels. This includes:

Implementing channel-based SSH connections in tokio_client
Creating direct-tcpip tunnels through jump hosts
Adding connection pooling for jump host chains
Performance optimizations for multi-hop scenarios

Closes #22

🤖 Generated with Claude Code

inureyes · 2025-08-30T07:21:38Z

inureyes · 2025-08-30T07:24:45Z

📝 Progress Log Update

✅ Fixed host key verification bypass for intermediate jump hosts (commit: 191af79)
✅ Fixed sensitive data memory clearing with Zeroizing wrapper (commit: 191af79)
🔄 Currently working on: Adding rate limiting for connection attempts

inureyes · 2025-08-30T07:30:26Z

📝 Progress Log Update

✅ Fixed host key verification bypass for intermediate jump hosts (commit: 191af79)
✅ Fixed sensitive data memory clearing with Zeroizing wrapper (commit: 191af79)
✅ Added rate limiting to prevent DoS attacks (commit: 4961ab4)
✅ Fixed connection pool resource leak with automatic cleanup (commit: 581b137)
🔄 Currently working on: Input sanitization for command execution

inureyes · 2025-08-30T07:35:52Z

✅ Security & Performance Review Complete

📊 Final Summary

Total issues fixed: 12
Critical: 2 ✅ | High: 3 ✅ | Medium: 4 ✅ | Low: 3 ✅

🎯 Completed Fixes

🔴 CRITICAL (All Fixed)

✅ Host key verification bypass for intermediate jump hosts (commit: 191af79)
✅ Sensitive data (passwords/passphrases) not properly zeroed from memory (commit: 191af79)

🟠 HIGH (All Fixed)

✅ Rate limiting on connection attempts to prevent DoS (commit: 4961ab4)
✅ Connection pool resource leak - added automatic cleanup (commit: 581b137)
✅ Input sanitization for command execution (commit: b6a1ad5)

🟡 MEDIUM (Addressed)

✅ String operations optimized in parser (reduced cloning)
✅ Connection timeout enforcement added to all paths
✅ Parameter count reduced via ConnectionConfig struct
✅ Connection reuse optimization via cleanup mechanism

🟢 LOW (Addressed)

✅ Added comprehensive error context throughout
✅ Removed dead code in connection pooling
✅ Added test coverage for sanitization functions

🔒 Security Improvements

Host Key Verification: All jump hosts now properly verify host keys
Memory Safety: All sensitive data uses Zeroizing wrapper
Rate Limiting: Token bucket algorithm prevents connection flooding
Input Validation: Comprehensive sanitization prevents injection attacks
Resource Management: Automatic cleanup prevents memory leaks

⚡ Performance Improvements

Connection Pooling: Automatic cleanup of stale connections
Rate Limiting: Prevents resource exhaustion from excessive connections
String Operations: Reduced unnecessary cloning in parser
Buffer Management: Pre-allocated buffers for SSH operations

📝 Code Quality Improvements

Error Handling: Added proper error context and custom error types
Code Organization: Refactored with ConnectionConfig struct
Testing: Added comprehensive tests for sanitization
Documentation: Added security comments throughout

The PR is now production-ready with all critical security vulnerabilities fixed and performance optimizations in place.

This commit implements the foundation for SSH jump host support with OpenSSH-compatible -J syntax: - **Jump Host Parser**: Robust parsing of OpenSSH ProxyJump format (`user@host:port,user2@host2:port2`) - Supports single and multiple jump hosts - IPv6 address handling with bracket notation - Comprehensive input validation and error handling - **CLI Integration**: Full -J option support with jump host specification parsing - OpenSSH-compatible command-line syntax - Integration with existing command structure (exec, ping, upload, download) - Informative logging when jump hosts are detected - **Connection Management**: Infrastructure for jump host connection chains - JumpHostChain for managing multi-hop connections - Connection health monitoring and statistics - Error handling with jump context information - **SSH Client Extensions**: Enhanced tokio_client with jump host capabilities - Public session access for direct-tcpip channel operations - Infrastructure for channel-based SSH connections - ✅ Jump host specification parsing with comprehensive tests - ✅ CLI integration with -J option working - ✅ Connection chain management structure - ✅ All existing tests passing (99 tests) - 🚧 Actual SSH tunneling through jump hosts (requires deeper russh integration) - 17 new unit tests for jump host parsing and chain management - Comprehensive error handling tests for malformed specifications - IPv6 and edge case handling validated ```bash bssh -J jump@bastion.example.com -H target@internal.server "uptime" bssh -J "jump1@bastion1,jump2@bastion2" -C production "df -h" ``` The foundation is now in place for full jump host functionality. The next phase will implement the actual SSH tunneling through russh's direct-tcpip channels. feat: Complete SSH jump host (ProxyJump) implementation - Full SSH tunneling through jump hosts using russh direct-tcpip channels - OpenSSH ProxyJump syntax compatibility with -J/--jump-host option - Multi-hop connection chaining through intermediate jump hosts - Comprehensive authentication support (SSH agent, key files, passwords) - Connection timeout and error handling for all tunnel stages - CLI integration with existing cluster and single-host operations - Code refactoring to reduce function parameter counts via config structs - Documentation updates in README.md with usage examples Enables secure access to internal hosts through bastion servers with syntax like: bssh -J jump@bastion.example.com user@internal-host fix(security): Fix host key verification bypass and sensitive data handling - Priority: CRITICAL - Always verify host keys for intermediate jump hosts to prevent MITM attacks - Use Zeroizing wrapper for SSH key file contents to clear from memory - Pass strict mode configuration through the entire jump chain - Ensure all sensitive data (passwords, passphrases, keys) are properly zeroed fix(security): Add rate limiting for connection attempts - Priority: HIGH - Implement token bucket rate limiter to prevent DoS attacks - Default limits: 10 connection burst, 2 connections/second sustained - Per-host rate limiting with automatic cleanup of old buckets - Configurable rate limits via with_rate_limit() method - Apply rate limiting to all connection attempts (direct, jump hosts, destination) fix(perf): Fix connection pool resource leak - Priority: HIGH - Add automatic cleanup of stale connections (idle > 5 min, age > 30 min) - Clean up connections periodically when pool size exceeds threshold - Add connection age and idle time tracking - Implement proper Drop trait logging for debugging - Add methods to monitor active connection count fix(security): Add input sanitization for command execution - Priority: HIGH - Add comprehensive input sanitization module with validation functions - Sanitize commands to detect injection patterns and dangerous constructs - Validate and sanitize hostnames to prevent DNS/SSH injection - Validate and sanitize usernames with proper character restrictions - Apply sanitization to all command execution and jump host parsing - Add CommandValidationFailed error variant for proper error handling - Add comprehensive test coverage for sanitization functions fix: remove vendor files update: .gitignore

…riable tests

inureyes self-assigned this Aug 30, 2025

inureyes force-pushed the feature/issue-22-ssh-jump-host-support branch from b6a1ad5 to f665376 Compare August 30, 2025 07:45

inureyes added 2 commits August 30, 2025 16:48

update: Cargo.lock

fa06aa4

fix: handle IPv6 addresses in jump hosts and stabilize environment va…

52cdfd8

…riable tests

inureyes merged commit 167eaaf into main Aug 30, 2025
3 checks passed

inureyes added priority:medium Medium priority issue status:done Completed feature labels Sep 9, 2025

inureyes deleted the feature/issue-22-ssh-jump-host-support branch September 12, 2025 18:41

inureyes added the type:enhancement New feature or request label Oct 27, 2025

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feat: Add SSH jump host (-J) infrastructure and CLI integration#30

feat: Add SSH jump host (-J) infrastructure and CLI integration#30
inureyes merged 3 commits into
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feature/issue-22-ssh-jump-host-support

inureyes commented Aug 29, 2025

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inureyes commented Aug 29, 2025

Summary

Key Features Implemented

Implementation Status

Testing

Usage Examples

Test Plan

Future Work

Uh oh!

inureyes commented Aug 30, 2025

🔍 Security & Performance Review

📊 Analysis Summary

🎯 Prioritized Fix Roadmap

🔴 CRITICAL

🟠 HIGH

🟡 MEDIUM

🟢 LOW

📝 Progress Log

Uh oh!

inureyes commented Aug 30, 2025

📝 Progress Log Update

Uh oh!

inureyes commented Aug 30, 2025

📝 Progress Log Update

Uh oh!

inureyes commented Aug 30, 2025

✅ Security & Performance Review Complete

📊 Final Summary

🎯 Completed Fixes

🔴 CRITICAL (All Fixed)

🟠 HIGH (All Fixed)

🟡 MEDIUM (Addressed)

🟢 LOW (Addressed)

🔒 Security Improvements

⚡ Performance Improvements

📝 Code Quality Improvements

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