dht

README

DHT is a distributed hash table based on the Kademlia paper:
https://pdos.csail.mit.edu/~petar/papers/maymounkov-kademlia-lncs.pdf.

It also uses the S/Kademlia extension "crypto puzzles" to impede Eclipse and
Sybil attacks (see the PROTOCOL, section 14 "Node ID Generation" for details).
S/Kademlia paper: https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.68.4986&rep=rep1&type=pdf

DHT also includes many other security measures:
	- Node IDs are Ed25519 keypairs.
	- All messages are signed by the node's private key.
	- All messages are encrypted with the recipient's public key.
	- Fixed-size (UDP) messages are padded to avoid leaking message type.

The network is completely decentralized. For more details read the PROTOCOL.

To operate a node:

1. Install golang: golang.org/dl

On Linux distributions like Ubuntu, Fedora, etc. you should be able to install a
"golang" package through your package manager.

2. Download dht with:

	go get -u github.com/esote/dht/cmd/dht

This will create a "dht" executable in your go/bin folder. Add ~/go/bin to PATH.

3. Create a working directory, for example

	mkdir /tmp/dht

3. Start a node

	dht /tmp/dht start PORT

The program will ask for a password to encrypt the node's private key.

4. Stop a node

	dht /tmp/dht stop

5. Bootstrap another node

	dht /tmp/dht bootstrap ID IP:PORT

		Bootstrap a node, ID must be full base64 code, IP must be an
		IPv4 or IPv6 address (hostnames not allowed).

6. Store a file on the network

	dht /tmp/dht store /PATH/TO/FILE

7. Load a file from the network

	dht /tmp/dht load KEY /PATH/TO/OUTPUT

		KEY must be full base64 code.

Documentation

Index

• type DHT
  • func NewDHT(config *DHTConfig) (*DHT, error)
  • func (dht *DHT) Bootstrap(id []byte, ip net.IP, port uint16) (err error)
  • func (dht *DHT) Close() error
  • func (dht *DHT) Load(key []byte) (io.ReadCloser, uint64, error)
  • func (dht *DHT) Store(key []byte, length uint64, value Rereader) error
• type DHTConfig
• type LogLevel
  • func (l LogLevel) String() string
• type Logger
  • func NewConsoleLogger(min LogLevel) Logger
• type Rereader

Types

type DHT

type DHT struct {
	// contains filtered or unexported fields
}

func NewDHT

func NewDHT(config *DHTConfig) (*DHT, error)

func (*DHT) Bootstrap

func (dht *DHT) Bootstrap(id []byte, ip net.IP, port uint16) (err error)

func (*DHT) Close

func (dht *DHT) Close() error

func (*DHT) Load

func (dht *DHT) Load(key []byte) (io.ReadCloser, uint64, error)

func (*DHT) Store

func (dht *DHT) Store(key []byte, length uint64, value Rereader) error

type DHTConfig

type DHTConfig struct {
	NetworkID     []byte
	Dir           string
	Password      []byte
	Storer        storer.Storer
	Logger        Logger
	IP            net.IP
	Port          uint16
	FixedTimeout  time.Duration // Timeout for fixed-length messages
	StreamTimeout time.Duration // Timeout for stream messages
	// contains filtered or unexported fields
}

type LogLevel

type LogLevel int

LogLevel is the priority of an event

const (
	//LogCrit    LogLevel = iota // Critical error, requiring DHT to exit
	LogErr     LogLevel = iota // Error with DHT
	LogWarning                 // Error from external request
	LogInfo                    // DHT operation information
	LogDebug                   // Debug details
)

TODO: ensure all logging follows these categories Log levels

func (LogLevel) String

func (l LogLevel) String() string

type Logger

type Logger interface {
	Log(level LogLevel, a ...interface{})
	Logf(level LogLevel, format string, a ...interface{})
}

Logger records events of varying importance.

func NewConsoleLogger

func NewConsoleLogger(min LogLevel) Logger

NewConsoleLogger records logs to the console: stdout if level >= LogInfo, otherwise stderr.

type Rereader

type Rereader interface {
	Next() (io.ReadCloser, error)
}

Rereader returns a new reader for the same source, allowing its stream to be "reread".