SFTP Management
SFTP Management Module: Comprehensive Technical Documentation
For The Satoshi Terminal
Table of Contents
Abstract
Architectural Overview
Secure Communication Protocol Stack
Asynchronous Data Flow Design
Subsystem Modularity
Connection Configuration
Advanced Authentication Mechanisms
Network Topology Considerations
SSH Session Layer Protocol Specifications
File Transfer Lifecycle
Session Negotiation and Key Exchange
Cryptographic Data Handling
Integrity Verification via MAC Algorithms
Advanced Automation and Scheduling
CRON-Compatible Recurrence Framework
Dependency-Driven Workflow Triggers
Multi-Dimensional Task Parallelization
Operational Diagnostics
Deep Packet Inspection for SFTP Layers
Network Latency Profiling and Optimization
Transfer Queue Contention Resolution
Security Framework
NIST-Compliant Key Rotation Policies
Elliptic Curve Cryptography Implementation
Hardening Against MITM and Replay Attacks
Integration Interfaces
RESTful API Endpoint Enumeration
Event-Driven Webhook Architecture
RPC-based Transfer Orchestration
Performance Tuning
Bandwidth Throttling and Prioritization
Dynamic Buffer Size Allocation
Multi-Threaded File Block Processing
Compliance and Auditability
PCI DSS Data Flow Mapping
SOX-Compliant Logging Infrastructure
ISO/IEC 27001 Alignment Metrics
Troubleshooting and Support Escalation
Low-Level Error Code Analysis
Configuration Anomaly Detection Algorithms
Tiered Support Procedures
Glossary of Technical Terms
Appendices
Supported Cipher Suites
RFC References
1. Abstract
The SFTP Management Module of The Satoshi Terminal represents an apex implementation of secure file transfer systems, utilizing SSH-2 (RFC 4251) as a foundational framework. Its architecture integrates cryptographic rigor with operational flexibility, ensuring robust, low-latency, and scalable data exchange mechanisms. This documentation elucidates every facet of its operation, optimized for technically advanced users and system architects.
2. Architectural Overview
2.1 Secure Communication Protocol Stack
The module operates atop the SSH Transport Layer Protocol (RFC 4253), leveraging:
Diffie-Hellman Key Exchange (DHKE): Secures the pre-authentication handshake.
AES-GCM Encryption: Ensures high-speed, low-overhead payload encryption.
HMAC-SHA2: Protects data integrity through keyed hash algorithms.
2.2 Asynchronous Data Flow Design
The system employs event-driven I/O mechanisms (e.g., epoll/kqueue):
Non-blocking Sockets: Minimize thread contention.
Transfer Pipelining: Parallelizes file segmentation for optimized throughput.
2.3 Subsystem Modularity
Connection Manager: Stateless design for rapid reinitialization during disruptions.
Scheduler Kernel: CRON-enhanced internal timing engine.
Audit Layer: Immutable append-only logging for regulatory compliance.
3. Connection Configuration
3.1 Advanced Authentication Mechanisms
Public Key Authentication (RFC 4252):
RSA (2048-bit minimum) and ECDSA support.
Configurable certificate-based trust anchors.
Host-Based Authentication:
Leverages the client's machine identity via FQDN mapping.
Password-Based Authentication: Secured with bcrypt hashing and challenge-response protocols.
3.2 Network Topology Considerations
NAT Traversal: Automatic handling of network address translations.
IPv6 Compatibility: Dual-stack configurations for hybrid environments.
TLS Layer Integration: Optional encapsulation for added transport security.
3.3 SSH Session Layer Protocol Specifications
Adaptive compression via zlib reduces payload overhead.
Key re-exchange triggers every 1 GB or 60 minutes (configurable).
4. File Transfer Lifecycle
4.1 Session Negotiation and Key Exchange
Client Init Message (SSH_MSG_KEXINIT): Initiates cryptographic parameters.
Server Response: Selects compatible cipher suite.
Session Confirmation: Establishes bidirectional encryption.
4.2 Cryptographic Data Handling
Uses AES-256-GCM for payloads with inline MAC verification.
All keys derived via HKDF (HMAC-based Key Derivation Function).
4.3 Integrity Verification via MAC Algorithms
SHA2-256 ensures tamper-evident data blocks.
Configurable retries for hash mismatches.
5. Advanced Automation and Scheduling
5.1 CRON-Compatible Recurrence Framework
Enables granular scheduling with UNIX CRON syntax.
Supports "at least once" delivery guarantees for critical transfers.
5.2 Dependency-Driven Workflow Triggers
Triggers include:
File system events (inotify/FSChange hooks).
RESTful API callbacks.
Log-based triggers for dynamic workflow reconfiguration.
5.3 Multi-Dimensional Task Parallelization
Uses weighted round-robin algorithms to allocate resources across tasks.
Isolates I/O threads to reduce CPU-bound contention.
6. Operational Diagnostics
6.1 Deep Packet Inspection for SFTP Layers
Analyzes SSH_MSG_CHANNEL_DATA packets for performance bottlenecks.
Identifies protocol anomalies (e.g., undefined opcode requests).
6.2 Network Latency Profiling and Optimization
Measures RTT (Round-Trip Time) per connection.
Dynamically adjusts TCP window size based on observed throughput.
6.3 Transfer Queue Contention Resolution
Implements priority inversion mitigation.
Supports dynamic queue reordering based on SLA parameters.
7. Security Framework
7.1 NIST-Compliant Key Rotation Policies
Automates private key lifecycle with configurable rotation intervals.
Supports "grace period" key overlap for seamless transitions.
7.2 Elliptic Curve Cryptography Implementation
ECDH over P-256 (prime256v1) ensures high-security with minimal CPU impact.
7.3 Hardening Against MITM and Replay Attacks
Session replay prevented via nonce-based sequence numbering.
Mitigates downgrade attacks with enforced cipher suite pinning.
8. Integration Interfaces
8.1 RESTful API Endpoint Enumeration
POST /api/v1/sftp/upload: Initiates secure file uploads.
GET /api/v1/sftp/status: Fetches real-time connection diagnostics.
DELETE /api/v1/sftp/session: Terminates live sessions forcefully.
8.2 Event-Driven Webhook Architecture
Pushes updates for:
Transfer completion events.
Authentication anomalies.
SLA breach notifications.
8.3 RPC-Based Transfer Orchestration
Uses gRPC for high-throughput, low-latency task management.
9. Performance Tuning
9.1 Bandwidth Throttling and Prioritization
Rate limiting enforced via token bucket algorithms.
QoS tagging for prioritizing critical transfers.
9.2 Dynamic Buffer Size Allocation
Adaptive resizing based on:
Current congestion levels.
Packet loss statistics.
9.3 Multi-Threaded File Block Processing
Implements scatter/gather I/O to maximize disk and network concurrency.
10. Compliance and Auditability
10.1 PCI DSS Data Flow Mapping
Provides comprehensive transfer flowcharts.
Verifies encryption at all stages of the pipeline.
10.2 SOX-Compliant Logging Infrastructure
Timestamped logs with cryptographic integrity checks.
Audit trails for user actions and automated processes.
10.3 ISO/IEC 27001 Alignment Metrics
Automated checks for compliance with Annex A.10 (Cryptography).
11. Troubleshooting and Support Escalation
11.1 Low-Level Error Code Analysis
Error codes (e.g.,
SSH_DISCONNECT_HOST_NOT_ALLOWED) mapped to resolution guides.
11.2 Configuration Anomaly Detection Algorithms
Detects misconfigurations in:
Key formats.
Network policies.
11.3 Tiered Support Procedures
Tier 1: Initial diagnosis using built-in tools.
Tier 2: Escalation to backend specialists.
Tier 3: Collaboration with external server administrators.
12. Glossary of Technical Terms
13. Appendices
Supported Cipher Suites
AES-256-GCM
ChaCha20-Poly1305
AES-128-CTR
RFC References
RFC 4251 (SSH Protocol Architecture)
RFC 4253 (SSH Transport Layer Protocol)
Last updated