SMTF – Send Me The File (yes, thats the name)

SMTF is a secure, peer-to-peer file transfer system over TCP designed with minimal trust assumptions and no central servers. It emphasizes direct connectivity, modern cryptography, and robust protocol design for safe and reliable file transfers between peers.

Note: This Tool expects the sender to be publicly available.

Feature	Description
Architecture	Pure peer-to-peer file transfer over TCP with no central servers, brokers, or relays. Peers connect directly.
Session Security	Ephemeral secrets are generated per transfer session using secure OS randomness. No long-term shared secrets, reducing replay and key-compromise risk.
Data Protection	End-to-end encryption using ChaCha20-Poly1305. Data is encrypted in fixed-size chunks to support large files, partial transfer recovery, and per-chunk integrity and authentication.
Key Exchange & Forward Secrecy	Per-session encryption keys derived using X25519 Diffie-Hellman and HKDF. Ensures forward secrecy, cryptographic isolation between transfers, and no key reuse across sessions.

Requirements

• Git
• Rust (rustc and cargo)
• TCP connectivity between peers

Installation and Build

Windows

1. Install Git Bash

   Download and install Git for Windows (includes Git Bash) - https://git-scm.com/download/win

2. Install Rust (rustc and cargo)

   Install Rust using rustup - https://www.rust-lang.org/tools/install

   Ensure cargo is added to your PATH during installation.

3. Clone the repository

• Open Git Bash and run:

  git clone https://github.com/vamsi200/smtf/
  cd smtf

• Build the project

  cargo build --release

• The compiled binary will be available in:

  target/release/

Linux

1. Install Git

• Use your distribution’s package manager, for example:

  sudo pacman -S git        # Arch
  sudo apt install git      # Debian/Ubuntu
  sudo dnf install git      # Fedora

2. Install Rust (rustc and cargo)

• Install Rust using rustup:

  curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

• Reload your shell:

  source ~/.cargo/env

• Clone the repository

  git clone https://github.com/vamsi200/smtf/
  cd smtf

• Build the project

  cargo build --release

• The compiled binary will be available in:

  target/release/

Screenshots

Security Notes

• All cryptographic material is ephemeral and scoped to a single session.
• No plaintext file data is transmitted over the network (except the file information at the start of send, which I will change).
• Each transfer is isolated to prevent key reuse or cross-session compromise.