The Great Renaming: hkexsh -> xs (Xperimental Shell)

Signed-off-by: Russ Magee <rmagee@gmail.com>

xsnet/consts.go

@@ -0,0 +1,113 @@
+// consts.go - consts for xsnet
+
+// Copyright (c) 2017-2019 Russell Magee
+// Licensed under the terms of the MIT license (see LICENSE.mit in this
+// distribution)
+//
+// golang implementation by Russ Magee (rmagee_at_gmail.com)
+package xsnet
+
+// KEX algorithm values
+//
+// Specified (in string form) as the extensions parameter
+// to xsnet.Dial()
+// Alg is sent in a uint8 so there are up to 256 possible
+const (
+	KEX_HERRADURA256 = iota // this MUST be first for default if omitted in ctor
+	KEX_HERRADURA512
+	KEX_HERRADURA1024
+	KEX_HERRADURA2048
+	KEX_resvd4
+	KEX_resvd5
+	KEX_resvd6
+	KEX_resvd7
+	KEX_KYBER512
+	KEX_KYBER768
+	KEX_KYBER1024
+	KEX_resvd11
+	KEX_NEWHOPE
+	KEX_NEWHOPE_SIMPLE // 'NewHopeLP-Simple' - https://eprint.iacr.org/2016/1157
+	KEX_resvd14
+	KEX_resvd15
+)
+
+// Sent from client to server in order to specify which
+// algo shall be used (see xsnet.KEX_HERRADURA256, ...)
+type KEXAlg uint8
+
+// Extended exit status codes - indicate comm/pty issues
+// rather than remote end normal UNIX exit codes
+const (
+	CSENone           = 1024 + iota
+	CSETruncCSO       // No CSOExitStatus in payload
+	CSEStillOpen      // Channel closed unexpectedly
+	CSEExecFail       // cmd.Start() (exec) failed
+	CSEPtyExecFail    // pty.Start() (exec w/pty) failed
+	CSEPtyGetNameFail // failed to obtain pty name
+)
+
+// Extended (>255 UNIX exit status) codes
+// This indicate channel-related or internal errors
+type CSExtendedCode uint32
+
+// Channel Status/Op bytes - packet types
+const (
+	// Main connection/session control
+	CSONone        = iota // No error, normal packet
+	CSOHmacInvalid        // HMAC mismatch detected on remote end
+	CSOTermSize           // set term size (rows:cols)
+	CSOExitStatus         // Remote cmd exit status
+	CSOChaff              // Dummy packet, do not pass beyond decryption
+
+	// Tunnel setup/control/status
+	CSOTunSetup     // client -> server tunnel setup request (dstport)
+	CSOTunSetupAck  // server -> client tunnel setup ack
+	CSOTunRefused   // server -> client: tunnel rport connection refused
+	CSOTunData      // packet contains tunnel data [rport:data]
+	CSOTunKeepAlive // client tunnel heartbeat
+	CSOTunDisconn   // server -> client: tunnel rport disconnected
+	CSOTunHangup    // client -> server: tunnel lport hung up
+)
+
+// TunEndpoint.tunCtl control values - used to control workers for client
+// or server tunnels depending on the code
+const (
+	TunCtl_Client_Listen = 'a'
+	// [CSOTunAccept]
+	// status: server has ack'd tun setup request
+	// action: client should accept (after re-listening, if required) on lport
+
+	TunCtl_Server_Dial = 'd' // server has dialled OK, client side can accept() conns
+	// [CSOTunAccept]
+	// status: client wants to open tunnel to rport
+	// action:server side should dial() rport on client's behalf
+)
+
+// Channel status Op byte type (see CSONone, ... and CSENone, ...)
+type CSOType uint32
+
+//TODO: this should be small (max unfragmented packet size?)
+const MAX_PAYLOAD_LEN = 4*1024*1024*1024 - 1
+
+// Session symmetric crypto algs
+const (
+	CAlgAES256     = iota
+	CAlgTwofish128 // golang.org/x/crypto/twofish
+	CAlgBlowfish64 // golang.org/x/crypto/blowfish
+	CAlgCryptMT1   //cryptmt using mtwist64
+	CAlgWanderer   // inhouse experimental crypto alg
+	CAlgNoneDisallowed
+)
+
+// Available ciphers for hkex.Conn
+type CSCipherAlg uint32
+
+// Session packet auth HMAC algs
+const (
+	HmacSHA256 = iota
+	HmacSHA512
+	HmacNoneDisallowed
+)
+
+// Available HMACs for hkex.Conn
+type CSHmacAlg uint32