[chore] remove vendor

1 files changed, 0 insertions, 786 deletions

diff --git a/vendor/golang.org/x/crypto/ssh/kex.go b/vendor/golang.org/x/crypto/ssh/kex.go
deleted file mode 100644
index 8a05f7990..000000000
--- a/vendor/golang.org/x/crypto/ssh/kex.go
+++ /dev/null
@@ -1,786 +0,0 @@
-// Copyright 2013 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package ssh
-
-import (
-	"crypto"
-	"crypto/ecdsa"
-	"crypto/elliptic"
-	"crypto/rand"
-	"crypto/subtle"
-	"encoding/binary"
-	"errors"
-	"fmt"
-	"io"
-	"math/big"
-
-	"golang.org/x/crypto/curve25519"
-)
-
-const (
-	kexAlgoDH1SHA1                = "diffie-hellman-group1-sha1"
-	kexAlgoDH14SHA1               = "diffie-hellman-group14-sha1"
-	kexAlgoDH14SHA256             = "diffie-hellman-group14-sha256"
-	kexAlgoDH16SHA512             = "diffie-hellman-group16-sha512"
-	kexAlgoECDH256                = "ecdh-sha2-nistp256"
-	kexAlgoECDH384                = "ecdh-sha2-nistp384"
-	kexAlgoECDH521                = "ecdh-sha2-nistp521"
-	kexAlgoCurve25519SHA256LibSSH = "curve25519-sha256@libssh.org"
-	kexAlgoCurve25519SHA256       = "curve25519-sha256"
-
-	// For the following kex only the client half contains a production
-	// ready implementation. The server half only consists of a minimal
-	// implementation to satisfy the automated tests.
-	kexAlgoDHGEXSHA1   = "diffie-hellman-group-exchange-sha1"
-	kexAlgoDHGEXSHA256 = "diffie-hellman-group-exchange-sha256"
-)
-
-// kexResult captures the outcome of a key exchange.
-type kexResult struct {
-	// Session hash. See also RFC 4253, section 8.
-	H []byte
-
-	// Shared secret. See also RFC 4253, section 8.
-	K []byte
-
-	// Host key as hashed into H.
-	HostKey []byte
-
-	// Signature of H.
-	Signature []byte
-
-	// A cryptographic hash function that matches the security
-	// level of the key exchange algorithm. It is used for
-	// calculating H, and for deriving keys from H and K.
-	Hash crypto.Hash
-
-	// The session ID, which is the first H computed. This is used
-	// to derive key material inside the transport.
-	SessionID []byte
-}
-
-// handshakeMagics contains data that is always included in the
-// session hash.
-type handshakeMagics struct {
-	clientVersion, serverVersion []byte
-	clientKexInit, serverKexInit []byte
-}
-
-func (m *handshakeMagics) write(w io.Writer) {
-	writeString(w, m.clientVersion)
-	writeString(w, m.serverVersion)
-	writeString(w, m.clientKexInit)
-	writeString(w, m.serverKexInit)
-}
-
-// kexAlgorithm abstracts different key exchange algorithms.
-type kexAlgorithm interface {
-	// Server runs server-side key agreement, signing the result
-	// with a hostkey. algo is the negotiated algorithm, and may
-	// be a certificate type.
-	Server(p packetConn, rand io.Reader, magics *handshakeMagics, s AlgorithmSigner, algo string) (*kexResult, error)
-
-	// Client runs the client-side key agreement. Caller is
-	// responsible for verifying the host key signature.
-	Client(p packetConn, rand io.Reader, magics *handshakeMagics) (*kexResult, error)
-}
-
-// dhGroup is a multiplicative group suitable for implementing Diffie-Hellman key agreement.
-type dhGroup struct {
-	g, p, pMinus1 *big.Int
-	hashFunc      crypto.Hash
-}
-
-func (group *dhGroup) diffieHellman(theirPublic, myPrivate *big.Int) (*big.Int, error) {
-	if theirPublic.Cmp(bigOne) <= 0 || theirPublic.Cmp(group.pMinus1) >= 0 {
-		return nil, errors.New("ssh: DH parameter out of bounds")
-	}
-	return new(big.Int).Exp(theirPublic, myPrivate, group.p), nil
-}
-
-func (group *dhGroup) Client(c packetConn, randSource io.Reader, magics *handshakeMagics) (*kexResult, error) {
-	var x *big.Int
-	for {
-		var err error
-		if x, err = rand.Int(randSource, group.pMinus1); err != nil {
-			return nil, err
-		}
-		if x.Sign() > 0 {
-			break
-		}
-	}
-
-	X := new(big.Int).Exp(group.g, x, group.p)
-	kexDHInit := kexDHInitMsg{
-		X: X,
-	}
-	if err := c.writePacket(Marshal(&kexDHInit)); err != nil {
-		return nil, err
-	}
-
-	packet, err := c.readPacket()
-	if err != nil {
-		return nil, err
-	}
-
-	var kexDHReply kexDHReplyMsg
-	if err = Unmarshal(packet, &kexDHReply); err != nil {
-		return nil, err
-	}
-
-	ki, err := group.diffieHellman(kexDHReply.Y, x)
-	if err != nil {
-		return nil, err
-	}
-
-	h := group.hashFunc.New()
-	magics.write(h)
-	writeString(h, kexDHReply.HostKey)
-	writeInt(h, X)
-	writeInt(h, kexDHReply.Y)
-	K := make([]byte, intLength(ki))
-	marshalInt(K, ki)
-	h.Write(K)
-
-	return &kexResult{
-		H:         h.Sum(nil),
-		K:         K,
-		HostKey:   kexDHReply.HostKey,
-		Signature: kexDHReply.Signature,
-		Hash:      group.hashFunc,
-	}, nil
-}
-
-func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
-	packet, err := c.readPacket()
-	if err != nil {
-		return
-	}
-	var kexDHInit kexDHInitMsg
-	if err = Unmarshal(packet, &kexDHInit); err != nil {
-		return
-	}
-
-	var y *big.Int
-	for {
-		if y, err = rand.Int(randSource, group.pMinus1); err != nil {
-			return
-		}
-		if y.Sign() > 0 {
-			break
-		}
-	}
-
-	Y := new(big.Int).Exp(group.g, y, group.p)
-	ki, err := group.diffieHellman(kexDHInit.X, y)
-	if err != nil {
-		return nil, err
-	}
-
-	hostKeyBytes := priv.PublicKey().Marshal()
-
-	h := group.hashFunc.New()
-	magics.write(h)
-	writeString(h, hostKeyBytes)
-	writeInt(h, kexDHInit.X)
-	writeInt(h, Y)
-
-	K := make([]byte, intLength(ki))
-	marshalInt(K, ki)
-	h.Write(K)
-
-	H := h.Sum(nil)
-
-	// H is already a hash, but the hostkey signing will apply its
-	// own key-specific hash algorithm.
-	sig, err := signAndMarshal(priv, randSource, H, algo)
-	if err != nil {
-		return nil, err
-	}
-
-	kexDHReply := kexDHReplyMsg{
-		HostKey:   hostKeyBytes,
-		Y:         Y,
-		Signature: sig,
-	}
-	packet = Marshal(&kexDHReply)
-
-	err = c.writePacket(packet)
-	return &kexResult{
-		H:         H,
-		K:         K,
-		HostKey:   hostKeyBytes,
-		Signature: sig,
-		Hash:      group.hashFunc,
-	}, err
-}
-
-// ecdh performs Elliptic Curve Diffie-Hellman key exchange as
-// described in RFC 5656, section 4.
-type ecdh struct {
-	curve elliptic.Curve
-}
-
-func (kex *ecdh) Client(c packetConn, rand io.Reader, magics *handshakeMagics) (*kexResult, error) {
-	ephKey, err := ecdsa.GenerateKey(kex.curve, rand)
-	if err != nil {
-		return nil, err
-	}
-
-	kexInit := kexECDHInitMsg{
-		ClientPubKey: elliptic.Marshal(kex.curve, ephKey.PublicKey.X, ephKey.PublicKey.Y),
-	}
-
-	serialized := Marshal(&kexInit)
-	if err := c.writePacket(serialized); err != nil {
-		return nil, err
-	}
-
-	packet, err := c.readPacket()
-	if err != nil {
-		return nil, err
-	}
-
-	var reply kexECDHReplyMsg
-	if err = Unmarshal(packet, &reply); err != nil {
-		return nil, err
-	}
-
-	x, y, err := unmarshalECKey(kex.curve, reply.EphemeralPubKey)
-	if err != nil {
-		return nil, err
-	}
-
-	// generate shared secret
-	secret, _ := kex.curve.ScalarMult(x, y, ephKey.D.Bytes())
-
-	h := ecHash(kex.curve).New()
-	magics.write(h)
-	writeString(h, reply.HostKey)
-	writeString(h, kexInit.ClientPubKey)
-	writeString(h, reply.EphemeralPubKey)
-	K := make([]byte, intLength(secret))
-	marshalInt(K, secret)
-	h.Write(K)
-
-	return &kexResult{
-		H:         h.Sum(nil),
-		K:         K,
-		HostKey:   reply.HostKey,
-		Signature: reply.Signature,
-		Hash:      ecHash(kex.curve),
-	}, nil
-}
-
-// unmarshalECKey parses and checks an EC key.
-func unmarshalECKey(curve elliptic.Curve, pubkey []byte) (x, y *big.Int, err error) {
-	x, y = elliptic.Unmarshal(curve, pubkey)
-	if x == nil {
-		return nil, nil, errors.New("ssh: elliptic.Unmarshal failure")
-	}
-	if !validateECPublicKey(curve, x, y) {
-		return nil, nil, errors.New("ssh: public key not on curve")
-	}
-	return x, y, nil
-}
-
-// validateECPublicKey checks that the point is a valid public key for
-// the given curve. See [SEC1], 3.2.2
-func validateECPublicKey(curve elliptic.Curve, x, y *big.Int) bool {
-	if x.Sign() == 0 && y.Sign() == 0 {
-		return false
-	}
-
-	if x.Cmp(curve.Params().P) >= 0 {
-		return false
-	}
-
-	if y.Cmp(curve.Params().P) >= 0 {
-		return false
-	}
-
-	if !curve.IsOnCurve(x, y) {
-		return false
-	}
-
-	// We don't check if N * PubKey == 0, since
-	//
-	// - the NIST curves have cofactor = 1, so this is implicit.
-	// (We don't foresee an implementation that supports non NIST
-	// curves)
-	//
-	// - for ephemeral keys, we don't need to worry about small
-	// subgroup attacks.
-	return true
-}
-
-func (kex *ecdh) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
-	packet, err := c.readPacket()
-	if err != nil {
-		return nil, err
-	}
-
-	var kexECDHInit kexECDHInitMsg
-	if err = Unmarshal(packet, &kexECDHInit); err != nil {
-		return nil, err
-	}
-
-	clientX, clientY, err := unmarshalECKey(kex.curve, kexECDHInit.ClientPubKey)
-	if err != nil {
-		return nil, err
-	}
-
-	// We could cache this key across multiple users/multiple
-	// connection attempts, but the benefit is small. OpenSSH
-	// generates a new key for each incoming connection.
-	ephKey, err := ecdsa.GenerateKey(kex.curve, rand)
-	if err != nil {
-		return nil, err
-	}
-
-	hostKeyBytes := priv.PublicKey().Marshal()
-
-	serializedEphKey := elliptic.Marshal(kex.curve, ephKey.PublicKey.X, ephKey.PublicKey.Y)
-
-	// generate shared secret
-	secret, _ := kex.curve.ScalarMult(clientX, clientY, ephKey.D.Bytes())
-
-	h := ecHash(kex.curve).New()
-	magics.write(h)
-	writeString(h, hostKeyBytes)
-	writeString(h, kexECDHInit.ClientPubKey)
-	writeString(h, serializedEphKey)
-
-	K := make([]byte, intLength(secret))
-	marshalInt(K, secret)
-	h.Write(K)
-
-	H := h.Sum(nil)
-
-	// H is already a hash, but the hostkey signing will apply its
-	// own key-specific hash algorithm.
-	sig, err := signAndMarshal(priv, rand, H, algo)
-	if err != nil {
-		return nil, err
-	}
-
-	reply := kexECDHReplyMsg{
-		EphemeralPubKey: serializedEphKey,
-		HostKey:         hostKeyBytes,
-		Signature:       sig,
-	}
-
-	serialized := Marshal(&reply)
-	if err := c.writePacket(serialized); err != nil {
-		return nil, err
-	}
-
-	return &kexResult{
-		H:         H,
-		K:         K,
-		HostKey:   reply.HostKey,
-		Signature: sig,
-		Hash:      ecHash(kex.curve),
-	}, nil
-}
-
-// ecHash returns the hash to match the given elliptic curve, see RFC
-// 5656, section 6.2.1
-func ecHash(curve elliptic.Curve) crypto.Hash {
-	bitSize := curve.Params().BitSize
-	switch {
-	case bitSize <= 256:
-		return crypto.SHA256
-	case bitSize <= 384:
-		return crypto.SHA384
-	}
-	return crypto.SHA512
-}
-
-var kexAlgoMap = map[string]kexAlgorithm{}
-
-func init() {
-	// This is the group called diffie-hellman-group1-sha1 in
-	// RFC 4253 and Oakley Group 2 in RFC 2409.
-	p, _ := new(big.Int).SetString("FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF", 16)
-	kexAlgoMap[kexAlgoDH1SHA1] = &dhGroup{
-		g:        new(big.Int).SetInt64(2),
-		p:        p,
-		pMinus1:  new(big.Int).Sub(p, bigOne),
-		hashFunc: crypto.SHA1,
-	}
-
-	// This are the groups called diffie-hellman-group14-sha1 and
-	// diffie-hellman-group14-sha256 in RFC 4253 and RFC 8268,
-	// and Oakley Group 14 in RFC 3526.
-	p, _ = new(big.Int).SetString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
-	group14 := &dhGroup{
-		g:       new(big.Int).SetInt64(2),
-		p:       p,
-		pMinus1: new(big.Int).Sub(p, bigOne),
-	}
-
-	kexAlgoMap[kexAlgoDH14SHA1] = &dhGroup{
-		g: group14.g, p: group14.p, pMinus1: group14.pMinus1,
-		hashFunc: crypto.SHA1,
-	}
-	kexAlgoMap[kexAlgoDH14SHA256] = &dhGroup{
-		g: group14.g, p: group14.p, pMinus1: group14.pMinus1,
-		hashFunc: crypto.SHA256,
-	}
-
-	// This is the group called diffie-hellman-group16-sha512 in RFC
-	// 8268 and Oakley Group 16 in RFC 3526.
-	p, _ = new(big.Int).SetString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
-
-	kexAlgoMap[kexAlgoDH16SHA512] = &dhGroup{
-		g:        new(big.Int).SetInt64(2),
-		p:        p,
-		pMinus1:  new(big.Int).Sub(p, bigOne),
-		hashFunc: crypto.SHA512,
-	}
-
-	kexAlgoMap[kexAlgoECDH521] = &ecdh{elliptic.P521()}
-	kexAlgoMap[kexAlgoECDH384] = &ecdh{elliptic.P384()}
-	kexAlgoMap[kexAlgoECDH256] = &ecdh{elliptic.P256()}
-	kexAlgoMap[kexAlgoCurve25519SHA256] = &curve25519sha256{}
-	kexAlgoMap[kexAlgoCurve25519SHA256LibSSH] = &curve25519sha256{}
-	kexAlgoMap[kexAlgoDHGEXSHA1] = &dhGEXSHA{hashFunc: crypto.SHA1}
-	kexAlgoMap[kexAlgoDHGEXSHA256] = &dhGEXSHA{hashFunc: crypto.SHA256}
-}
-
-// curve25519sha256 implements the curve25519-sha256 (formerly known as
-// curve25519-sha256@libssh.org) key exchange method, as described in RFC 8731.
-type curve25519sha256 struct{}
-
-type curve25519KeyPair struct {
-	priv [32]byte
-	pub  [32]byte
-}
-
-func (kp *curve25519KeyPair) generate(rand io.Reader) error {
-	if _, err := io.ReadFull(rand, kp.priv[:]); err != nil {
-		return err
-	}
-	curve25519.ScalarBaseMult(&kp.pub, &kp.priv)
-	return nil
-}
-
-// curve25519Zeros is just an array of 32 zero bytes so that we have something
-// convenient to compare against in order to reject curve25519 points with the
-// wrong order.
-var curve25519Zeros [32]byte
-
-func (kex *curve25519sha256) Client(c packetConn, rand io.Reader, magics *handshakeMagics) (*kexResult, error) {
-	var kp curve25519KeyPair
-	if err := kp.generate(rand); err != nil {
-		return nil, err
-	}
-	if err := c.writePacket(Marshal(&kexECDHInitMsg{kp.pub[:]})); err != nil {
-		return nil, err
-	}
-
-	packet, err := c.readPacket()
-	if err != nil {
-		return nil, err
-	}
-
-	var reply kexECDHReplyMsg
-	if err = Unmarshal(packet, &reply); err != nil {
-		return nil, err
-	}
-	if len(reply.EphemeralPubKey) != 32 {
-		return nil, errors.New("ssh: peer's curve25519 public value has wrong length")
-	}
-
-	var servPub, secret [32]byte
-	copy(servPub[:], reply.EphemeralPubKey)
-	curve25519.ScalarMult(&secret, &kp.priv, &servPub)
-	if subtle.ConstantTimeCompare(secret[:], curve25519Zeros[:]) == 1 {
-		return nil, errors.New("ssh: peer's curve25519 public value has wrong order")
-	}
-
-	h := crypto.SHA256.New()
-	magics.write(h)
-	writeString(h, reply.HostKey)
-	writeString(h, kp.pub[:])
-	writeString(h, reply.EphemeralPubKey)
-
-	ki := new(big.Int).SetBytes(secret[:])
-	K := make([]byte, intLength(ki))
-	marshalInt(K, ki)
-	h.Write(K)
-
-	return &kexResult{
-		H:         h.Sum(nil),
-		K:         K,
-		HostKey:   reply.HostKey,
-		Signature: reply.Signature,
-		Hash:      crypto.SHA256,
-	}, nil
-}
-
-func (kex *curve25519sha256) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
-	packet, err := c.readPacket()
-	if err != nil {
-		return
-	}
-	var kexInit kexECDHInitMsg
-	if err = Unmarshal(packet, &kexInit); err != nil {
-		return
-	}
-
-	if len(kexInit.ClientPubKey) != 32 {
-		return nil, errors.New("ssh: peer's curve25519 public value has wrong length")
-	}
-
-	var kp curve25519KeyPair
-	if err := kp.generate(rand); err != nil {
-		return nil, err
-	}
-
-	var clientPub, secret [32]byte
-	copy(clientPub[:], kexInit.ClientPubKey)
-	curve25519.ScalarMult(&secret, &kp.priv, &clientPub)
-	if subtle.ConstantTimeCompare(secret[:], curve25519Zeros[:]) == 1 {
-		return nil, errors.New("ssh: peer's curve25519 public value has wrong order")
-	}
-
-	hostKeyBytes := priv.PublicKey().Marshal()
-
-	h := crypto.SHA256.New()
-	magics.write(h)
-	writeString(h, hostKeyBytes)
-	writeString(h, kexInit.ClientPubKey)
-	writeString(h, kp.pub[:])
-
-	ki := new(big.Int).SetBytes(secret[:])
-	K := make([]byte, intLength(ki))
-	marshalInt(K, ki)
-	h.Write(K)
-
-	H := h.Sum(nil)
-
-	sig, err := signAndMarshal(priv, rand, H, algo)
-	if err != nil {
-		return nil, err
-	}
-
-	reply := kexECDHReplyMsg{
-		EphemeralPubKey: kp.pub[:],
-		HostKey:         hostKeyBytes,
-		Signature:       sig,
-	}
-	if err := c.writePacket(Marshal(&reply)); err != nil {
-		return nil, err
-	}
-	return &kexResult{
-		H:         H,
-		K:         K,
-		HostKey:   hostKeyBytes,
-		Signature: sig,
-		Hash:      crypto.SHA256,
-	}, nil
-}
-
-// dhGEXSHA implements the diffie-hellman-group-exchange-sha1 and
-// diffie-hellman-group-exchange-sha256 key agreement protocols,
-// as described in RFC 4419
-type dhGEXSHA struct {
-	hashFunc crypto.Hash
-}
-
-const (
-	dhGroupExchangeMinimumBits   = 2048
-	dhGroupExchangePreferredBits = 2048
-	dhGroupExchangeMaximumBits   = 8192
-)
-
-func (gex *dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshakeMagics) (*kexResult, error) {
-	// Send GexRequest
-	kexDHGexRequest := kexDHGexRequestMsg{
-		MinBits:      dhGroupExchangeMinimumBits,
-		PreferedBits: dhGroupExchangePreferredBits,
-		MaxBits:      dhGroupExchangeMaximumBits,
-	}
-	if err := c.writePacket(Marshal(&kexDHGexRequest)); err != nil {
-		return nil, err
-	}
-
-	// Receive GexGroup
-	packet, err := c.readPacket()
-	if err != nil {
-		return nil, err
-	}
-
-	var msg kexDHGexGroupMsg
-	if err = Unmarshal(packet, &msg); err != nil {
-		return nil, err
-	}
-
-	// reject if p's bit length < dhGroupExchangeMinimumBits or > dhGroupExchangeMaximumBits
-	if msg.P.BitLen() < dhGroupExchangeMinimumBits || msg.P.BitLen() > dhGroupExchangeMaximumBits {
-		return nil, fmt.Errorf("ssh: server-generated gex p is out of range (%d bits)", msg.P.BitLen())
-	}
-
-	// Check if g is safe by verifying that 1 < g < p-1
-	pMinusOne := new(big.Int).Sub(msg.P, bigOne)
-	if msg.G.Cmp(bigOne) <= 0 || msg.G.Cmp(pMinusOne) >= 0 {
-		return nil, fmt.Errorf("ssh: server provided gex g is not safe")
-	}
-
-	// Send GexInit
-	pHalf := new(big.Int).Rsh(msg.P, 1)
-	x, err := rand.Int(randSource, pHalf)
-	if err != nil {
-		return nil, err
-	}
-	X := new(big.Int).Exp(msg.G, x, msg.P)
-	kexDHGexInit := kexDHGexInitMsg{
-		X: X,
-	}
-	if err := c.writePacket(Marshal(&kexDHGexInit)); err != nil {
-		return nil, err
-	}
-
-	// Receive GexReply
-	packet, err = c.readPacket()
-	if err != nil {
-		return nil, err
-	}
-
-	var kexDHGexReply kexDHGexReplyMsg
-	if err = Unmarshal(packet, &kexDHGexReply); err != nil {
-		return nil, err
-	}
-
-	if kexDHGexReply.Y.Cmp(bigOne) <= 0 || kexDHGexReply.Y.Cmp(pMinusOne) >= 0 {
-		return nil, errors.New("ssh: DH parameter out of bounds")
-	}
-	kInt := new(big.Int).Exp(kexDHGexReply.Y, x, msg.P)
-
-	// Check if k is safe by verifying that k > 1 and k < p - 1
-	if kInt.Cmp(bigOne) <= 0 || kInt.Cmp(pMinusOne) >= 0 {
-		return nil, fmt.Errorf("ssh: derived k is not safe")
-	}
-
-	h := gex.hashFunc.New()
-	magics.write(h)
-	writeString(h, kexDHGexReply.HostKey)
-	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMinimumBits))
-	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangePreferredBits))
-	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMaximumBits))
-	writeInt(h, msg.P)
-	writeInt(h, msg.G)
-	writeInt(h, X)
-	writeInt(h, kexDHGexReply.Y)
-	K := make([]byte, intLength(kInt))
-	marshalInt(K, kInt)
-	h.Write(K)
-
-	return &kexResult{
-		H:         h.Sum(nil),
-		K:         K,
-		HostKey:   kexDHGexReply.HostKey,
-		Signature: kexDHGexReply.Signature,
-		Hash:      gex.hashFunc,
-	}, nil
-}
-
-// Server half implementation of the Diffie Hellman Key Exchange with SHA1 and SHA256.
-//
-// This is a minimal implementation to satisfy the automated tests.
-func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
-	// Receive GexRequest
-	packet, err := c.readPacket()
-	if err != nil {
-		return
-	}
-	var kexDHGexRequest kexDHGexRequestMsg
-	if err = Unmarshal(packet, &kexDHGexRequest); err != nil {
-		return
-	}
-
-	// Send GexGroup
-	// This is the group called diffie-hellman-group14-sha1 in RFC
-	// 4253 and Oakley Group 14 in RFC 3526.
-	p, _ := new(big.Int).SetString("FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D670C354E4ABC9804F1746C08CA18217C32905E462E36CE3BE39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF6955817183995497CEA956AE515D2261898FA051015728E5A8AACAA68FFFFFFFFFFFFFFFF", 16)
-	g := big.NewInt(2)
-
-	msg := &kexDHGexGroupMsg{
-		P: p,
-		G: g,
-	}
-	if err := c.writePacket(Marshal(msg)); err != nil {
-		return nil, err
-	}
-
-	// Receive GexInit
-	packet, err = c.readPacket()
-	if err != nil {
-		return
-	}
-	var kexDHGexInit kexDHGexInitMsg
-	if err = Unmarshal(packet, &kexDHGexInit); err != nil {
-		return
-	}
-
-	pHalf := new(big.Int).Rsh(p, 1)
-
-	y, err := rand.Int(randSource, pHalf)
-	if err != nil {
-		return
-	}
-	Y := new(big.Int).Exp(g, y, p)
-
-	pMinusOne := new(big.Int).Sub(p, bigOne)
-	if kexDHGexInit.X.Cmp(bigOne) <= 0 || kexDHGexInit.X.Cmp(pMinusOne) >= 0 {
-		return nil, errors.New("ssh: DH parameter out of bounds")
-	}
-	kInt := new(big.Int).Exp(kexDHGexInit.X, y, p)
-
-	hostKeyBytes := priv.PublicKey().Marshal()
-
-	h := gex.hashFunc.New()
-	magics.write(h)
-	writeString(h, hostKeyBytes)
-	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMinimumBits))
-	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangePreferredBits))
-	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMaximumBits))
-	writeInt(h, p)
-	writeInt(h, g)
-	writeInt(h, kexDHGexInit.X)
-	writeInt(h, Y)
-
-	K := make([]byte, intLength(kInt))
-	marshalInt(K, kInt)
-	h.Write(K)
-
-	H := h.Sum(nil)
-
-	// H is already a hash, but the hostkey signing will apply its
-	// own key-specific hash algorithm.
-	sig, err := signAndMarshal(priv, randSource, H, algo)
-	if err != nil {
-		return nil, err
-	}
-
-	kexDHGexReply := kexDHGexReplyMsg{
-		HostKey:   hostKeyBytes,
-		Y:         Y,
-		Signature: sig,
-	}
-	packet = Marshal(&kexDHGexReply)
-
-	err = c.writePacket(packet)
-
-	return &kexResult{
-		H:         H,
-		K:         K,
-		HostKey:   hostKeyBytes,
-		Signature: sig,
-		Hash:      gex.hashFunc,
-	}, err
-}