PeerLink

PeerLink is a robust peer-to-peer (P2P) file transfer application designed to minimize reliance on centralized servers. Leveraging the power of libp2p and IPFS, PeerLink ensures secure, efficient, and reliable file sharing directly between users.

Table of Contents

• PeerLink
  • Table of Contents
  • Features
  • Usage
    • Sending a File
    • Receiving a File
  • Security
  • Contributing
  • Acknowledgements

Features

• Secure File Transfer: Utilizes Password-Authenticated Key Exchange (PAKE) for secure key exchange, ensuring that only intended recipients can access the files.
• File Verification: Implements SHA-256 checksums to verify the integrity of transferred files.
• File Transfer Confirmation: Allows the receiver to confirm the file transfer before saving it.
• Decentralized Networking: Built on libp2p and IPFS to provide a decentralized network infrastructure, eliminating the need for centralized servers.
• Automatic NAT Traversal: Enables seamless connections across different network configurations using libp2p's automatic NAT traversal features.

Usage

PeerLink operates through a command-line interface, offering two primary functionalities: sending and receiving files.

Sending a File

1. Run PeerLink:

   ./peerlink send <filename>

2. Share the Secret Words:

   After providing the file path, PeerLink generates four secret words. Share these securely with the intended receiver:

   Share the following four words with the receiver securely:
   word1 word2 word3 word4
   

3. Await Connection:

   The application waits for the receiver to connect and request the file:

   Waiting for the receiver to connect and request the file...
   

Warning

Sometimes, sending a file may fail due to an error in publishing the CID to the DHT. If this occurs, simply try the process again. This is a known issue with the underlying network and usually resolves on subsequent attempt. If anyone has a fix for this, please do create a PR!

Receiving a File

1. Run PeerLink:

   ./peerlink receive <input-passphrase>

2. Confirm File Transfer: You will be prompted to confirm the file transfer:

   Received file metadata:
   <file metadata>
   Do you want to receive the file? (y/n)
   

3. Receive and Verify File:

   PeerLink downloads the file, verifies its integrity using the SHA-256 checksum, and saves it to the specified location.

   File received successfully
   

Security

PeerLink prioritizes the security and integrity of file transfers through multiple mechanisms:

• Password-Authenticated Key Exchange (PAKE): Ensures that the key exchange process is secure and that only parties with the correct secret words can establish a shared encryption key.
• AES-GCM Encryption: All data transferred between peers is encrypted using AES-GCM, providing both confidentiality and integrity.
• SHA-256 Checksums: Each file transfer includes a SHA-256 checksum to verify that the file has not been tampered with or corrupted during transit.
• Decentralized Discovery: Utilizing libp2p's DHT for peer discovery reduces the risk of centralized points of failure or attack.
• NAT Traversal: Uses libp2p's automatic NAT traversal features to connect peers behind NATs.
• Direct Connection: Even if the receiver is behind a NAT, peerlink uses libp2p's hole punching feature to connect directly.

Contributing

Contributions are welcome! If you'd like to contribute to PeerLink, please open a pull request.

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Disclaimer: PeerLink is a community-driven project and is provided "as is" without any warranties. Use it at your own risk. Always ensure that you have the necessary permissions to share and access files.

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Acknowledgements

• libp2p
• IPFS
• PAKE
• pcp