Hookup

This module provides a uniform interface to network connections with optional support for TLS and SOCKS.

This library is careful to support both IPv4 and IPv6. It will attempt to all of the addresses that a domain name resolves to until one the first successful connection.

Use connect and close to establish and close network connections.

Use recv, recvLine, and send to receive and transmit data on an open network connection.

TLS and SOCKS parameters can be provided. When both are provided a connection will first be established to the SOCKS server and then the TLS connection will be established through that proxy server. This is most useful when connecting through a dynamic port forward of an SSH client via the -D flag.

Connections

data Connection

A connection to a network service along with its read buffer used for line-oriented protocols. The connection could be a plain network connection, SOCKS connected, or TLS.

connect

Arguments

:: ConnectionParams

parameters

-> IO Connection

open connection

Open network connection to TCP service specified by the given parameters.

The resulting connection MUST be closed with close to avoid leaking resources.

Throws IOError, SocksError, ProtocolError, ConnectionFailure

connectWithSocket

Arguments

:: ConnectionParams

parameters

-> Socket

connected socket

-> IO Connection

open connection

Create a new Connection using an already connected socket. This will attempt to start TLS if configured but will ignore any SOCKS server settings as it is assumed that the socket is already actively connected to the intended service.

Throws ProtocolError

close

Arguments

:: Connection

open connection

-> IO ()

Close network connection.

Reading and writing data

recv

Arguments

:: Connection

open connection

-> Int

maximum underlying recv size

-> IO ByteString

next chunk from stream

Receive the next chunk from the stream. This operation will first return the buffer if it contains a non-empty chunk. Otherwise it will request up to the requested number of bytes from the stream.

Throws: IOError, ConnectionAbruptlyTerminated, ProtocolError

recvLine

Arguments

:: Connection

open connection

-> Int

maximum line length

-> IO (Maybe ByteString)

next line or end-of-stream

Receive a line from the network connection. Both "\r\n" and "\n" are recognized.

Returning Nothing means that the peer has closed its half of the connection.

Unterminated lines will raise a LineTruncated exception. This can happen if the peer transmits some data and closes its end without transmitting a line terminator.

Throws: ConnectionAbruptlyTerminated, ProtocolError, ConnectionFailure, IOError

send

Arguments

:: Connection

open connection

-> ByteString

chunk

-> IO ()

Send bytes on the network connection. This ensures the whole chunk is transmitted, which might take multiple underlying sends.

Throws: IOError, ProtocolError

putBuf

Arguments

:: Connection

connection

-> ByteString

new head of buffer

-> IO ()

Push a ByteString onto the buffer so that it will be the first bytes to be read on the next receive operation. This could perhaps be useful for putting the unused portion of a recv back into the buffer for future recvLine or recv operations.

Configuration

data ConnectionParams

Parameters for connect.

Common defaults for fields: defaultFamily, defaultTlsParams

When a SocksParams is provided the connection will be established using a SOCKS (version 5) proxy.

When a TlsParams is provided the connection negotiate TLS at connect time in order to protect the stream.

The binding hostname can be used to force the connect to use a particular interface or IP protocol version.

Constructors

ConnectionParams

Fields

• cpHost :: HostName

  Destination host

• cpPort :: PortNumber

  Destination TCP port

• cpSocks :: Maybe SocksParams

  Optional SOCKS parameters

• cpTls :: Maybe TlsParams

  Optional TLS parameters

• cpBind :: Maybe HostName

  Source address to bind

data SocksParams

SOCKS connection parameters

Constructors

SocksParams

Fields

• spHost :: HostName

  SOCKS server host

• spPort :: PortNumber

  SOCKS server port

data TlsParams

TLS connection parameters. These parameters are passed to OpenSSL when making a secure connection.

Constructors

TlsParams

Fields

• tpClientCertificate :: Maybe FilePath

  Path to client certificate

• tpClientPrivateKey :: Maybe FilePath

  Path to client private key

• tpClientPrivateKeyPassword :: PemPasswordSupply

  Private key decryption password

• tpServerCertificate :: Maybe FilePath

  Path to CA certificate bundle

• tpCipherSuite :: String

  OpenSSL cipher suite name (e.g. "HIGH")

• tpInsecure :: Bool

  Disables certificate checking when True

data PemPasswordSupply

PemPasswordSupply represents a way to supply password.

FIXME: using PwTTY causes an error but I don't know why: "error:0906406D:PEM routines:DEF_CALLBACK:problems getting password"

Constructors

PwNone

no password

PwStr String

password in a static string

PwBS ByteString

password in a static bytestring.

PwCallback PemPasswordCallback

get a password by a callback

PwTTY

read a password from TTY

defaultTlsParams :: TlsParams

Default values for TLS that use no client certificates, use system CA root, "HIGH" cipher suite, and which validate hostnames.

Errors

data ConnectionFailure

Type for errors that can be thrown by this package.

Constructors

HostnameResolutionFailure HostName String

Failure during getAddrInfo resolving remote host

ConnectionFailure [IOError]

Failure during connect to remote host

LineTooLong

Failure during recvLine

LineTruncated

Incomplete line during recvLine

SocksError CommandReply

Socks command rejected by server by given reply code

SocksAuthenticationError

Socks authentication method was not accepted

SocksProtocolError

Socks server sent an invalid message or no message.

SocksBadDomainName

Domain name was too long for SOCKS protocol

Instances

Show ConnectionFailure

Defined in Hookup

Methods

showsPrec :: Int -> ConnectionFailure -> ShowS

show :: ConnectionFailure -> String

showList :: [ConnectionFailure] -> ShowS

Exception ConnectionFailure

displayException implemented for prettier messages

Defined in Hookup

Methods

toException :: ConnectionFailure -> SomeException

fromException :: SomeException -> Maybe ConnectionFailure

displayException :: ConnectionFailure -> String

newtype CommandReply

SOCKS command reply codes

Constructors

CommandReply Word8

Bundled Patterns

pattern Succeeded :: CommandReply

pattern GeneralFailure :: CommandReply

pattern NotAllowed :: CommandReply

pattern NetUnreachable :: CommandReply

pattern HostUnreachable :: CommandReply

pattern ConnectionRefused :: CommandReply

pattern TTLExpired :: CommandReply

pattern CmdNotSupported :: CommandReply

pattern AddrNotSupported :: CommandReply

Instances

Eq CommandReply

Defined in Hookup.Socks5

Methods

(==) :: CommandReply -> CommandReply -> Bool

(/=) :: CommandReply -> CommandReply -> Bool

Show CommandReply

Defined in Hookup.Socks5

Methods

showsPrec :: Int -> CommandReply -> ShowS

show :: CommandReply -> String

showList :: [CommandReply] -> ShowS

SSL Information

getClientCertificate :: Connection -> Maybe X509

Get peer certificate if one exists.

getPeerCertificate :: Connection -> IO (Maybe X509)

Get peer certificate if one exists.

getPeerCertFingerprintSha1 :: Connection -> IO (Maybe ByteString)

getPeerCertFingerprintSha256 :: Connection -> IO (Maybe ByteString)

getPeerCertFingerprintSha512 :: Connection -> IO (Maybe ByteString)

getPeerPubkeyFingerprintSha1 :: Connection -> IO (Maybe ByteString)

getPeerPubkeyFingerprintSha256 :: Connection -> IO (Maybe ByteString)

getPeerPubkeyFingerprintSha512 :: Connection -> IO (Maybe ByteString)