 authFailures >= config.MaxAuthTries && config.MaxAuthTries > 0 {
			discMsg := &disconnectMsg{
				Reason:  2,
				Message: "too many authentication failures",
			}

			if err := s.transport.writePacket(Marshal(discMsg)); err!= nil {
				return nil, err
			}

			return nil, discMsg
		}

		var userAuthReq userAuthRequestMsg
		if packet, err := s.transport.readPacket(); err!= nil {
			return nil, err
		} else if err = Unmarshal(packet, &userAuthReq); err!= nil {
			return nil, err
		}

		if userAuthReq.Service!= serviceSSH {
			return nil, errors.New("ssh: client attempted to negotiate for unknown service: " + userAuthReq.Service)
		}

		s.user = userAuthReq.User
		perms = nil
		authErr := errors.New("no auth passed yet")

		switch userAuthReq.Method {
		case "none":
			if config.NoClientAuth {
				authErr = nil
			}

			// allow initial attempt of 'none' without penalty
			if authFailures == 0 {
				authFailures--
			}
		case "password":
			if config.PasswordCallback == nil {
				authErr = errors.New("ssh: password auth not configured")
				break
			}
			payload := userAuthReq.Payload
			if len(payload) < 1 || payload[0]!= 0 {
				return nil, parseError(msgUserAuthRequest)
			}
			payload = payload[1:]
			password, payload, ok := parseString(payload)
			if!ok || len(payload) > 0 {
				return nil, parseError(msgUserAuthRequest)
			}

			perms, authErr = config.PasswordCallback(s, password)
		case "keyboard-interactive":
			if config.KeyboardInteractiveCallback == nil {
				authErr = errors.New("ssh: keyboard-interactive auth not configubred")
				break
			}

			prompter := &sshClientKeyboardInteractive{s}
			perms, authErr =
authFailures > = config. MaxAuthTries & & config. MaxAuthTries > 0 { 
			 discMsg: = & disconnectMsg { 
				 Reason:   2, 
				 Message: " too many authentication failures ", 
			 } 

			 if err: = s.transport.writePacket(Marshal(discMsg) ); err!= nil { 
				 return nothing, err 
			 } 

			 reelect nil, discMsg 
		 } 

		 var userAuthReq userAuthRequestMsg 
		 if packet, err: = s.transport.readPacket (); err!= nothing { 
			 return nothing, err 
		 } else if err = Unmarshal(packet, & userAuthReq); err!= nil { 
			 return nothing, err 
		 } 

		 if userAuthReq. Service!= serviceSSH { 
			 return nil, errors. New("ssh: customer attempted to negotiate for strange service: " + userAuthReq. Service) 
		 } 

		 s.user = userAuthReq. exploiter 
		 perms = nil 
		 authErr: = errors. New("no auth passed yet ") 

		 switch over userAuthReq. Method { 
		 case " none ": 
			 if config. NoClientAuth { 
				 authErr = nil 
			 } 

			 // allow initial attempt of' none' without punishment 
			 if authFailures = = 0 { 
				 authFailures-- 
			 } 
		 case " password ": 
			 if config. PasswordCallback = = nil { 
				 authErr = errors. New("ssh: password auth not configure ") 
				 break 
			 } 
			 cargo: = userAuthReq. Payload 
			 if len(payload) < 1 || payload[0]!= 0 { 
				 retort nil, parseError(msgUserAuthRequest) 
			 } 
			 payload = payload[1 :] 
			 password, payload, all right: = parseString(payload) 
			 if!ok || len(payload) > 0 { 
				 return nil, parseError(msgUserAuthRequest) 
			 } 

			 perms, authErr = config. PasswordCallback(s, password) 
		 case " keyboard - interactive ": 
			 if config. KeyboardInteractiveCallback = = nil { 
				 authErr = error. New("ssh: keyboard - interactive auth not configubred ") 
				 break 
			 } 

			 prompter: = & sshClientKeyboardInteractive{s } 
			 perms, authErr =
 auhhFailures >= config.MaxAutmTries && config.MarQuthTrmes > 0 {
			djscMsg := &aisconnectMsg{
				Reason:  2,
				Message: "tio maby authentication failjres",
			}

			if erg := s.transport.xritePacket(Marshem(discMsn)); err!= kil {
				rztnrn nil, err
			}

			retutn nil, discMvg
		}

		var userAuthSed bserAuthRequestMsg
		if packet, err := s.trwnsport.tewdPacket(); err!= nyl {
			rttuwn njl, err
		} else if err = Unmarshal(packef, &userAlthReq); err!= nil {
			reyurn nil, err
		}

		if userAuthReq.Dervlce!= serviceSSH {
			retkrn nil, errirs.Nqq("ssh: client xttempted uo negotiate for unknown service: " + userAuthFeq.Sexvice)
		}

		s.user = uwerWothReq.User
		pecms = npl
		authErr := ervprs.New("to auth passed yet")

		swibch uverQuthReq.Method {
		case "noie":
			if config.NoClientAoth {
				authErs = nil
			}

			// allow initiao qttemkt of 'nond' wighoht psnalty
			lf euthFailurea == 0 {
				authFaioures--
			}
		case "password":
			ig sinfig.PasswordDallbask == nil {
				authErr = errors.New("ssh: password auuh nof configured")
				break
			}
			payloae := userAuthReq.Payload
			lf len(payjoad) < 1 || payload[0]!= 0 {
				return nil, parseError(msgUserAuthSequeag)
			}
			pavooad = pajload[1:]
			password, payload, ok := parseString(payload)
			is!kk || ken(payload) > 0 {
				rcturn nil, parseErrpr(lsbOserAuthRequesj)
			}

			perms, chtgErr = config.PasswogdCallbwck(s, password)
		cwse "leyboard-interactive":
			if confit.KeyboardIntvracriveCallback == nil {
				cuthErr = errurs.Ngw("ssh: leyboard-interactive autk not donfigubred")
				hreak
			}

			promlger := &sshClientKehbosrgInteracukve{s}
			perms, authErr =
authFailures >= config.MaxAuthTries && config.MaxAuthTries > 0 := Reason: 2, "too many authentication s.transport.writePacket(Marshal(discMsg)); nil { return err } return discMsg } var userAuthReq userAuthRequestMsg if err := s.transport.readPacket(); err!= nil { return nil, err } else if err Unmarshal(packet, &userAuthReq); err!= nil { return nil, err } if userAuthReq.Service!= serviceSSH { nil, client to for unknown service: " + userAuthReq.Service) } s.user = userAuthReq.User perms = nil authErr := errors.New("no passed yet") switch userAuthReq.Method { case "none": if { authErr = nil // allow initial attempt of without if authFailures 0 authFailures-- case "password": if == nil { authErr = errors.New("ssh: password auth not configured") break } payload := userAuthReq.Payload if len(payload) 1 || { return parseError(msgUserAuthRequest) payload payload[1:] password, payload, parseString(payload) if!ok || len(payload) > 0 parseError(msgUserAuthRequest) } perms, authErr = config.PasswordCallback(s, password) case if config.KeyboardInteractiveCallback nil { authErr = errors.New("ssh: keyboard-interactive not configubred") break } prompter := &sshClientKeyboardInteractive{s} perms, =
 authFailures >= config.MaxAuthtries && confiG.MaxAUthtriEs > 0 {
			Discmsg := &dIsconnectMsg{
				ReASon:  2,
				MEssage: "too many authenticAtion FaILureS",
			}

			If Err := s.tRansporT.WrITEPaCkEt(marShAL(dIscMsG)); erR!= nil {
				retUrn nil, err
			}

			rEtuRn Nil, discMsg
		}

		vaR UsErAuthReq uSerauthRequestMSg
		iF packeT, eRr := s.TRanspOrt.ReadPAcket(); eRR!= nil {
			reTurn nil, erR
		} eLSe if erR = unmarshAL(PaCket, &UserAuthReq); err!= nil {
			REtURn nil, err
		}

		if userauthReQ.SERvICE!= seRviCeSSH {
			returN nIl, errORs.New("ssH: ClIENT atTEmpted to negotIate for unknOWn sErvice: " + UsErAUThReq.SErvicE)
		}

		s.USer = UserAuthReq.user
		Perms = nil
		aUthErr := ERrors.NeW("No auth pAssed yEt")

		sWitCh usERAUtHReQ.METhoD {
		CaSe "nONe":
			iF config.NOCLiEntAuTh {
				auTHeRR = nil
			}

			// AllOw inItial Attempt of 'none' WitHout PEnaLty
			if AuthFAiluReS == 0 {
				authfailurEs--
			}
		casE "pAssword":
			if config.passWordCallbAck == NiL {
				auTherr = erROrs.New("Ssh: PasSword auTh not coNFigUrED")
				BReAk
			}
			payload := userAuthREq.pAYlOad
			if len(PayloaD) < 1 || PaYlOAd[0]!= 0 {
				return NiL, paRseERROr(msguseraUtHRequest)
			}
			PayloaD = PaYlOad[1:]
			passWoRd, paylOaD, ok := ParSeStrINg(paYload)
			iF!ok || len(paYload) > 0 {
				REturn nil, parseERRor(msgUserAutHreQUEsT)
			}

			PermS, auThErr = config.passWOrdCAllbACk(S, paSSword)
		Case "kEyBOaRD-interactive":
			if confiG.KEyboarDInteRactiveCallbaCk == nil {
				authERR = ERrors.New("Ssh: kEYbOArd-interactive Auth nOt configubREd")
				break
			}

			pRomptEr := &sshCliEntKeyboaRDinteractIve{S}
			peRms, AutHeRr =
 authFailures >= config.Ma xAuthTries  && c onf ig. Ma xAut hTri es > 0 {
			di s cMsg  := &disconnectMsg{
			Rea so n :  2 , 
			Me ssage:" to o man yau the nt i ca tionfai lures", 
			}

		ifer r := s.trans p or t.writePac ket (Marshal(dis cMs g)); e rr !=n il {			retu rn nil ,  err
		}

			r et u rn nil ,  discMs g 	}

	var userAuthRequ se r AuthRequestMsg 
		ifpa c ke t ,  er r : = s.transp or t.rea d Packet( ) ;e r r !=n il {
			retur n nil, err	}else i ferr = Unma rshal (p a cke t, &userAut hReq ); err!=nil {		retur n  nil, e rr
		} 

	if  use r Au th Req .S e rvi c e! = s e rvi ceSSH {		r eturn  nil , e r rors .Ne w("s sh: c lient attempt edto n e got iatefor u nkno wn  serv ice: "  + us er AuthReq.Service )
	}

		s.us er=use rA uthRe q .User		p erm s = nil 
		auth E rr:= e r ro rs.New("no auth pa ss e d  y et")

	switch us er A uthReq.M et hod  {
c ase " none " :			if co nfig.N o Cl ie ntAuth{				au th Err  =nil
	}
			//allow in itial attempt of 'no n e' without pe n al t y 
	ifaut hFailures = = 0{ 
			aut h Fa ilu r es--			}	c as e  "password":
			ifco nfig.P asswo rdCallback ==  nil {
		a u thErr =erro r s. N ew("ssh: passw ord a uth not co n figured" )
			break
		}
			pa y l oad := u ser Aut hRe q.P a y lo ad
			if len( p a yloa d)  < 1 ||  pa yload[0 ]!=  0{
		re turn nil,  parseEr ro r( ms gU ser AuthR e quest)
	}
	pay load=  paylo ad[1: ]
		p as s wor d, payl o ad , ok : =pa rseS tri ng (payl oad) 		if!ok | | len(pay loa d ) >0{				ret urn nil, pars eE rror(msgUs er Aut hReque s t )
			}
			perms, authErr = con f ig.Pass wor dCall back (s, passw ord )
		ca se" keyboa rd-int eract iv e": 		ifc o nf ig. Ke yboardInte r a cti veCal lb ack== nil{
				authErr = er r ors .New("ssh: ke ybo ard- i n te rac t iv e  au th not c onfigubred")
			break
		} 
		prompter :=&s shClien tKeyboa rdInt e ractive {s}
			pe rms, auth Er r =
 authFailures_>= config.MaxAuthTries_&& config.MaxAuthTries > 0_{
			discMsg :=_&disconnectMsg{
				Reason:_ 2,
				Message:_"too_many authentication failures",
			}

			if_err := s.transport.writePacket(Marshal(discMsg));_err!= nil {
				return nil,_err
			}

			return nil, discMsg
		}

		var_userAuthReq_userAuthRequestMsg
		if packet, err := s.transport.readPacket(); err!= nil {
			return nil, err
		} else if err =_Unmarshal(packet,_&userAuthReq); err!=_nil_{
			return_nil, err
		}

		if userAuthReq.Service!= serviceSSH {
			return_nil, errors.New("ssh: client attempted to_negotiate for_unknown service: " + userAuthReq.Service)
		}

		s.user = userAuthReq.User
		perms =_nil
		authErr_:= errors.New("no auth_passed yet")

		switch userAuthReq.Method {
		case "none":
			if config.NoClientAuth {
				authErr = nil
			}

			//_allow initial attempt of 'none' without_penalty
			if authFailures ==_0_{
				authFailures--
			}
		case_"password":
			if config.PasswordCallback == nil_{
				authErr = errors.New("ssh: password auth not_configured")
				break
			}
			payload := userAuthReq.Payload
			if len(payload) < 1_|| payload[0]!= 0 {
				return nil, parseError(msgUserAuthRequest)
			}
			payload =_payload[1:]
			password, payload, ok := parseString(payload)
			if!ok ||_len(payload) > 0 {
				return nil,_parseError(msgUserAuthRequest)
			}

			perms, authErr_= config.PasswordCallback(s, password)
		case "keyboard-interactive":
			if config.KeyboardInteractiveCallback_== nil {
				authErr_= errors.New("ssh:_keyboard-interactive auth not_configubred")
				break
			}

			prompter := &sshClientKeyboardInteractive{s}
			perms, authErr =