mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-12-11 23:50:19 +00:00
3010f033c5
Bumps the golang-dependencies group with 2 updates: [golang.org/x/crypto](https://github.com/golang/crypto) and [golang.org/x/net](https://github.com/golang/net). Updates `golang.org/x/crypto` from 0.14.0 to 0.15.0 - [Commits](https://github.com/golang/crypto/compare/v0.14.0...v0.15.0) Updates `golang.org/x/net` from 0.17.0 to 0.18.0 - [Commits](https://github.com/golang/net/compare/v0.17.0...v0.18.0) --- updated-dependencies: - dependency-name: golang.org/x/crypto dependency-type: direct:production update-type: version-update:semver-minor dependency-group: golang-dependencies - dependency-name: golang.org/x/net dependency-type: direct:production update-type: version-update:semver-minor dependency-group: golang-dependencies ... Signed-off-by: dependabot[bot] <support@github.com>
759 lines
20 KiB
Go
759 lines
20 KiB
Go
// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package ssh
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import (
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"crypto/rand"
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"errors"
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"fmt"
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"io"
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"log"
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"net"
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"strings"
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"sync"
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)
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// debugHandshake, if set, prints messages sent and received. Key
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// exchange messages are printed as if DH were used, so the debug
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// messages are wrong when using ECDH.
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const debugHandshake = false
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// chanSize sets the amount of buffering SSH connections. This is
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// primarily for testing: setting chanSize=0 uncovers deadlocks more
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// quickly.
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const chanSize = 16
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// keyingTransport is a packet based transport that supports key
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// changes. It need not be thread-safe. It should pass through
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// msgNewKeys in both directions.
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type keyingTransport interface {
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packetConn
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// prepareKeyChange sets up a key change. The key change for a
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// direction will be effected if a msgNewKeys message is sent
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// or received.
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prepareKeyChange(*algorithms, *kexResult) error
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}
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// handshakeTransport implements rekeying on top of a keyingTransport
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// and offers a thread-safe writePacket() interface.
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type handshakeTransport struct {
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conn keyingTransport
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config *Config
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serverVersion []byte
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clientVersion []byte
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// hostKeys is non-empty if we are the server. In that case,
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// it contains all host keys that can be used to sign the
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// connection.
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hostKeys []Signer
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// publicKeyAuthAlgorithms is non-empty if we are the server. In that case,
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// it contains the supported client public key authentication algorithms.
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publicKeyAuthAlgorithms []string
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// hostKeyAlgorithms is non-empty if we are the client. In that case,
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// we accept these key types from the server as host key.
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hostKeyAlgorithms []string
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// On read error, incoming is closed, and readError is set.
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incoming chan []byte
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readError error
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mu sync.Mutex
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writeError error
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sentInitPacket []byte
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sentInitMsg *kexInitMsg
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pendingPackets [][]byte // Used when a key exchange is in progress.
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writePacketsLeft uint32
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writeBytesLeft int64
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// If the read loop wants to schedule a kex, it pings this
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// channel, and the write loop will send out a kex
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// message.
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requestKex chan struct{}
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// If the other side requests or confirms a kex, its kexInit
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// packet is sent here for the write loop to find it.
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startKex chan *pendingKex
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kexLoopDone chan struct{} // closed (with writeError non-nil) when kexLoop exits
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// data for host key checking
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hostKeyCallback HostKeyCallback
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dialAddress string
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remoteAddr net.Addr
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// bannerCallback is non-empty if we are the client and it has been set in
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// ClientConfig. In that case it is called during the user authentication
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// dance to handle a custom server's message.
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bannerCallback BannerCallback
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// Algorithms agreed in the last key exchange.
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algorithms *algorithms
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// Counters exclusively owned by readLoop.
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readPacketsLeft uint32
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readBytesLeft int64
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// The session ID or nil if first kex did not complete yet.
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sessionID []byte
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}
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type pendingKex struct {
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otherInit []byte
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done chan error
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}
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func newHandshakeTransport(conn keyingTransport, config *Config, clientVersion, serverVersion []byte) *handshakeTransport {
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t := &handshakeTransport{
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conn: conn,
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serverVersion: serverVersion,
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clientVersion: clientVersion,
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incoming: make(chan []byte, chanSize),
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requestKex: make(chan struct{}, 1),
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startKex: make(chan *pendingKex),
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kexLoopDone: make(chan struct{}),
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config: config,
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}
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t.resetReadThresholds()
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t.resetWriteThresholds()
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// We always start with a mandatory key exchange.
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t.requestKex <- struct{}{}
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return t
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}
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func newClientTransport(conn keyingTransport, clientVersion, serverVersion []byte, config *ClientConfig, dialAddr string, addr net.Addr) *handshakeTransport {
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t := newHandshakeTransport(conn, &config.Config, clientVersion, serverVersion)
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t.dialAddress = dialAddr
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t.remoteAddr = addr
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t.hostKeyCallback = config.HostKeyCallback
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t.bannerCallback = config.BannerCallback
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if config.HostKeyAlgorithms != nil {
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t.hostKeyAlgorithms = config.HostKeyAlgorithms
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} else {
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t.hostKeyAlgorithms = supportedHostKeyAlgos
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}
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go t.readLoop()
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go t.kexLoop()
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return t
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}
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func newServerTransport(conn keyingTransport, clientVersion, serverVersion []byte, config *ServerConfig) *handshakeTransport {
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t := newHandshakeTransport(conn, &config.Config, clientVersion, serverVersion)
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t.hostKeys = config.hostKeys
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t.publicKeyAuthAlgorithms = config.PublicKeyAuthAlgorithms
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go t.readLoop()
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go t.kexLoop()
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return t
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}
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func (t *handshakeTransport) getSessionID() []byte {
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return t.sessionID
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}
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// waitSession waits for the session to be established. This should be
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// the first thing to call after instantiating handshakeTransport.
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func (t *handshakeTransport) waitSession() error {
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p, err := t.readPacket()
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if err != nil {
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return err
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}
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if p[0] != msgNewKeys {
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return fmt.Errorf("ssh: first packet should be msgNewKeys")
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}
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return nil
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}
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func (t *handshakeTransport) id() string {
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if len(t.hostKeys) > 0 {
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return "server"
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}
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return "client"
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}
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func (t *handshakeTransport) printPacket(p []byte, write bool) {
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action := "got"
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if write {
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action = "sent"
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}
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if p[0] == msgChannelData || p[0] == msgChannelExtendedData {
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log.Printf("%s %s data (packet %d bytes)", t.id(), action, len(p))
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} else {
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msg, err := decode(p)
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log.Printf("%s %s %T %v (%v)", t.id(), action, msg, msg, err)
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}
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}
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func (t *handshakeTransport) readPacket() ([]byte, error) {
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p, ok := <-t.incoming
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if !ok {
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return nil, t.readError
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}
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return p, nil
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}
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func (t *handshakeTransport) readLoop() {
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first := true
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for {
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p, err := t.readOnePacket(first)
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first = false
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if err != nil {
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t.readError = err
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close(t.incoming)
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break
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}
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if p[0] == msgIgnore || p[0] == msgDebug {
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continue
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}
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t.incoming <- p
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}
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// Stop writers too.
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t.recordWriteError(t.readError)
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// Unblock the writer should it wait for this.
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close(t.startKex)
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// Don't close t.requestKex; it's also written to from writePacket.
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}
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func (t *handshakeTransport) pushPacket(p []byte) error {
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if debugHandshake {
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t.printPacket(p, true)
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}
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return t.conn.writePacket(p)
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}
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func (t *handshakeTransport) getWriteError() error {
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t.mu.Lock()
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defer t.mu.Unlock()
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return t.writeError
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}
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func (t *handshakeTransport) recordWriteError(err error) {
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t.mu.Lock()
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defer t.mu.Unlock()
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if t.writeError == nil && err != nil {
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t.writeError = err
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}
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}
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func (t *handshakeTransport) requestKeyExchange() {
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select {
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case t.requestKex <- struct{}{}:
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default:
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// something already requested a kex, so do nothing.
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}
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}
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func (t *handshakeTransport) resetWriteThresholds() {
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t.writePacketsLeft = packetRekeyThreshold
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if t.config.RekeyThreshold > 0 {
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t.writeBytesLeft = int64(t.config.RekeyThreshold)
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} else if t.algorithms != nil {
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t.writeBytesLeft = t.algorithms.w.rekeyBytes()
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} else {
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t.writeBytesLeft = 1 << 30
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}
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}
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func (t *handshakeTransport) kexLoop() {
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write:
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for t.getWriteError() == nil {
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var request *pendingKex
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var sent bool
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for request == nil || !sent {
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var ok bool
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select {
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case request, ok = <-t.startKex:
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if !ok {
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break write
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}
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case <-t.requestKex:
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break
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}
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if !sent {
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if err := t.sendKexInit(); err != nil {
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t.recordWriteError(err)
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break
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}
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sent = true
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}
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}
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if err := t.getWriteError(); err != nil {
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if request != nil {
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request.done <- err
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}
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break
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}
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// We're not servicing t.requestKex, but that is OK:
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// we never block on sending to t.requestKex.
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// We're not servicing t.startKex, but the remote end
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// has just sent us a kexInitMsg, so it can't send
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// another key change request, until we close the done
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// channel on the pendingKex request.
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err := t.enterKeyExchange(request.otherInit)
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t.mu.Lock()
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t.writeError = err
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t.sentInitPacket = nil
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t.sentInitMsg = nil
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t.resetWriteThresholds()
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// we have completed the key exchange. Since the
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// reader is still blocked, it is safe to clear out
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// the requestKex channel. This avoids the situation
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// where: 1) we consumed our own request for the
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// initial kex, and 2) the kex from the remote side
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// caused another send on the requestKex channel,
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clear:
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for {
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select {
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case <-t.requestKex:
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//
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default:
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break clear
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}
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}
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request.done <- t.writeError
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// kex finished. Push packets that we received while
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// the kex was in progress. Don't look at t.startKex
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// and don't increment writtenSinceKex: if we trigger
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// another kex while we are still busy with the last
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// one, things will become very confusing.
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for _, p := range t.pendingPackets {
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t.writeError = t.pushPacket(p)
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if t.writeError != nil {
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break
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}
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}
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t.pendingPackets = t.pendingPackets[:0]
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t.mu.Unlock()
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}
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// Unblock reader.
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t.conn.Close()
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// drain startKex channel. We don't service t.requestKex
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// because nobody does blocking sends there.
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for request := range t.startKex {
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request.done <- t.getWriteError()
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}
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// Mark that the loop is done so that Close can return.
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close(t.kexLoopDone)
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}
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// The protocol uses uint32 for packet counters, so we can't let them
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// reach 1<<32. We will actually read and write more packets than
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// this, though: the other side may send more packets, and after we
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// hit this limit on writing we will send a few more packets for the
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// key exchange itself.
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const packetRekeyThreshold = (1 << 31)
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func (t *handshakeTransport) resetReadThresholds() {
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t.readPacketsLeft = packetRekeyThreshold
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if t.config.RekeyThreshold > 0 {
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t.readBytesLeft = int64(t.config.RekeyThreshold)
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} else if t.algorithms != nil {
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t.readBytesLeft = t.algorithms.r.rekeyBytes()
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} else {
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t.readBytesLeft = 1 << 30
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}
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}
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func (t *handshakeTransport) readOnePacket(first bool) ([]byte, error) {
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p, err := t.conn.readPacket()
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if err != nil {
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return nil, err
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}
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if t.readPacketsLeft > 0 {
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t.readPacketsLeft--
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} else {
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t.requestKeyExchange()
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}
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if t.readBytesLeft > 0 {
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t.readBytesLeft -= int64(len(p))
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} else {
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t.requestKeyExchange()
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}
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if debugHandshake {
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t.printPacket(p, false)
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}
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if first && p[0] != msgKexInit {
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return nil, fmt.Errorf("ssh: first packet should be msgKexInit")
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}
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if p[0] != msgKexInit {
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return p, nil
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}
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firstKex := t.sessionID == nil
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kex := pendingKex{
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done: make(chan error, 1),
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otherInit: p,
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}
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t.startKex <- &kex
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err = <-kex.done
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if debugHandshake {
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log.Printf("%s exited key exchange (first %v), err %v", t.id(), firstKex, err)
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}
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if err != nil {
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return nil, err
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}
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t.resetReadThresholds()
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// By default, a key exchange is hidden from higher layers by
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// translating it into msgIgnore.
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successPacket := []byte{msgIgnore}
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if firstKex {
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// sendKexInit() for the first kex waits for
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// msgNewKeys so the authentication process is
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// guaranteed to happen over an encrypted transport.
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successPacket = []byte{msgNewKeys}
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}
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return successPacket, nil
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}
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// sendKexInit sends a key change message.
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func (t *handshakeTransport) sendKexInit() error {
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t.mu.Lock()
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defer t.mu.Unlock()
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if t.sentInitMsg != nil {
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// kexInits may be sent either in response to the other side,
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// or because our side wants to initiate a key change, so we
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// may have already sent a kexInit. In that case, don't send a
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// second kexInit.
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return nil
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}
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msg := &kexInitMsg{
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KexAlgos: t.config.KeyExchanges,
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CiphersClientServer: t.config.Ciphers,
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CiphersServerClient: t.config.Ciphers,
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MACsClientServer: t.config.MACs,
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MACsServerClient: t.config.MACs,
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CompressionClientServer: supportedCompressions,
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CompressionServerClient: supportedCompressions,
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}
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io.ReadFull(rand.Reader, msg.Cookie[:])
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isServer := len(t.hostKeys) > 0
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if isServer {
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for _, k := range t.hostKeys {
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// If k is a MultiAlgorithmSigner, we restrict the signature
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// algorithms. If k is a AlgorithmSigner, presume it supports all
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// signature algorithms associated with the key format. If k is not
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// an AlgorithmSigner, we can only assume it only supports the
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// algorithms that matches the key format. (This means that Sign
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// can't pick a different default).
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keyFormat := k.PublicKey().Type()
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switch s := k.(type) {
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case MultiAlgorithmSigner:
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for _, algo := range algorithmsForKeyFormat(keyFormat) {
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if contains(s.Algorithms(), underlyingAlgo(algo)) {
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msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, algo)
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}
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}
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case AlgorithmSigner:
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msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, algorithmsForKeyFormat(keyFormat)...)
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default:
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msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, keyFormat)
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}
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}
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} else {
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msg.ServerHostKeyAlgos = t.hostKeyAlgorithms
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// As a client we opt in to receiving SSH_MSG_EXT_INFO so we know what
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// algorithms the server supports for public key authentication. See RFC
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// 8308, Section 2.1.
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if firstKeyExchange := t.sessionID == nil; firstKeyExchange {
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msg.KexAlgos = make([]string, 0, len(t.config.KeyExchanges)+1)
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msg.KexAlgos = append(msg.KexAlgos, t.config.KeyExchanges...)
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msg.KexAlgos = append(msg.KexAlgos, "ext-info-c")
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}
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}
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packet := Marshal(msg)
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// writePacket destroys the contents, so save a copy.
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packetCopy := make([]byte, len(packet))
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copy(packetCopy, packet)
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if err := t.pushPacket(packetCopy); err != nil {
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return err
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}
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t.sentInitMsg = msg
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t.sentInitPacket = packet
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return nil
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}
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func (t *handshakeTransport) writePacket(p []byte) error {
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switch p[0] {
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case msgKexInit:
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return errors.New("ssh: only handshakeTransport can send kexInit")
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case msgNewKeys:
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return errors.New("ssh: only handshakeTransport can send newKeys")
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}
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t.mu.Lock()
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defer t.mu.Unlock()
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if t.writeError != nil {
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return t.writeError
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}
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if t.sentInitMsg != nil {
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// Copy the packet so the writer can reuse the buffer.
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cp := make([]byte, len(p))
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copy(cp, p)
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t.pendingPackets = append(t.pendingPackets, cp)
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return nil
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}
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if t.writeBytesLeft > 0 {
|
|
t.writeBytesLeft -= int64(len(p))
|
|
} else {
|
|
t.requestKeyExchange()
|
|
}
|
|
|
|
if t.writePacketsLeft > 0 {
|
|
t.writePacketsLeft--
|
|
} else {
|
|
t.requestKeyExchange()
|
|
}
|
|
|
|
if err := t.pushPacket(p); err != nil {
|
|
t.writeError = err
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (t *handshakeTransport) Close() error {
|
|
// Close the connection. This should cause the readLoop goroutine to wake up
|
|
// and close t.startKex, which will shut down kexLoop if running.
|
|
err := t.conn.Close()
|
|
|
|
// Wait for the kexLoop goroutine to complete.
|
|
// At that point we know that the readLoop goroutine is complete too,
|
|
// because kexLoop itself waits for readLoop to close the startKex channel.
|
|
<-t.kexLoopDone
|
|
|
|
return err
|
|
}
|
|
|
|
func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
|
|
if debugHandshake {
|
|
log.Printf("%s entered key exchange", t.id())
|
|
}
|
|
|
|
otherInit := &kexInitMsg{}
|
|
if err := Unmarshal(otherInitPacket, otherInit); err != nil {
|
|
return err
|
|
}
|
|
|
|
magics := handshakeMagics{
|
|
clientVersion: t.clientVersion,
|
|
serverVersion: t.serverVersion,
|
|
clientKexInit: otherInitPacket,
|
|
serverKexInit: t.sentInitPacket,
|
|
}
|
|
|
|
clientInit := otherInit
|
|
serverInit := t.sentInitMsg
|
|
isClient := len(t.hostKeys) == 0
|
|
if isClient {
|
|
clientInit, serverInit = serverInit, clientInit
|
|
|
|
magics.clientKexInit = t.sentInitPacket
|
|
magics.serverKexInit = otherInitPacket
|
|
}
|
|
|
|
var err error
|
|
t.algorithms, err = findAgreedAlgorithms(isClient, clientInit, serverInit)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// We don't send FirstKexFollows, but we handle receiving it.
|
|
//
|
|
// RFC 4253 section 7 defines the kex and the agreement method for
|
|
// first_kex_packet_follows. It states that the guessed packet
|
|
// should be ignored if the "kex algorithm and/or the host
|
|
// key algorithm is guessed wrong (server and client have
|
|
// different preferred algorithm), or if any of the other
|
|
// algorithms cannot be agreed upon". The other algorithms have
|
|
// already been checked above so the kex algorithm and host key
|
|
// algorithm are checked here.
|
|
if otherInit.FirstKexFollows && (clientInit.KexAlgos[0] != serverInit.KexAlgos[0] || clientInit.ServerHostKeyAlgos[0] != serverInit.ServerHostKeyAlgos[0]) {
|
|
// other side sent a kex message for the wrong algorithm,
|
|
// which we have to ignore.
|
|
if _, err := t.conn.readPacket(); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
kex, ok := kexAlgoMap[t.algorithms.kex]
|
|
if !ok {
|
|
return fmt.Errorf("ssh: unexpected key exchange algorithm %v", t.algorithms.kex)
|
|
}
|
|
|
|
var result *kexResult
|
|
if len(t.hostKeys) > 0 {
|
|
result, err = t.server(kex, &magics)
|
|
} else {
|
|
result, err = t.client(kex, &magics)
|
|
}
|
|
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
firstKeyExchange := t.sessionID == nil
|
|
if firstKeyExchange {
|
|
t.sessionID = result.H
|
|
}
|
|
result.SessionID = t.sessionID
|
|
|
|
if err := t.conn.prepareKeyChange(t.algorithms, result); err != nil {
|
|
return err
|
|
}
|
|
if err = t.conn.writePacket([]byte{msgNewKeys}); err != nil {
|
|
return err
|
|
}
|
|
|
|
// On the server side, after the first SSH_MSG_NEWKEYS, send a SSH_MSG_EXT_INFO
|
|
// message with the server-sig-algs extension if the client supports it. See
|
|
// RFC 8308, Sections 2.4 and 3.1, and [PROTOCOL], Section 1.9.
|
|
if !isClient && firstKeyExchange && contains(clientInit.KexAlgos, "ext-info-c") {
|
|
supportedPubKeyAuthAlgosList := strings.Join(t.publicKeyAuthAlgorithms, ",")
|
|
extInfo := &extInfoMsg{
|
|
NumExtensions: 2,
|
|
Payload: make([]byte, 0, 4+15+4+len(supportedPubKeyAuthAlgosList)+4+16+4+1),
|
|
}
|
|
extInfo.Payload = appendInt(extInfo.Payload, len("server-sig-algs"))
|
|
extInfo.Payload = append(extInfo.Payload, "server-sig-algs"...)
|
|
extInfo.Payload = appendInt(extInfo.Payload, len(supportedPubKeyAuthAlgosList))
|
|
extInfo.Payload = append(extInfo.Payload, supportedPubKeyAuthAlgosList...)
|
|
extInfo.Payload = appendInt(extInfo.Payload, len("ping@openssh.com"))
|
|
extInfo.Payload = append(extInfo.Payload, "ping@openssh.com"...)
|
|
extInfo.Payload = appendInt(extInfo.Payload, 1)
|
|
extInfo.Payload = append(extInfo.Payload, "0"...)
|
|
if err := t.conn.writePacket(Marshal(extInfo)); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
if packet, err := t.conn.readPacket(); err != nil {
|
|
return err
|
|
} else if packet[0] != msgNewKeys {
|
|
return unexpectedMessageError(msgNewKeys, packet[0])
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// algorithmSignerWrapper is an AlgorithmSigner that only supports the default
|
|
// key format algorithm.
|
|
//
|
|
// This is technically a violation of the AlgorithmSigner interface, but it
|
|
// should be unreachable given where we use this. Anyway, at least it returns an
|
|
// error instead of panicing or producing an incorrect signature.
|
|
type algorithmSignerWrapper struct {
|
|
Signer
|
|
}
|
|
|
|
func (a algorithmSignerWrapper) SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error) {
|
|
if algorithm != underlyingAlgo(a.PublicKey().Type()) {
|
|
return nil, errors.New("ssh: internal error: algorithmSignerWrapper invoked with non-default algorithm")
|
|
}
|
|
return a.Sign(rand, data)
|
|
}
|
|
|
|
func pickHostKey(hostKeys []Signer, algo string) AlgorithmSigner {
|
|
for _, k := range hostKeys {
|
|
if s, ok := k.(MultiAlgorithmSigner); ok {
|
|
if !contains(s.Algorithms(), underlyingAlgo(algo)) {
|
|
continue
|
|
}
|
|
}
|
|
|
|
if algo == k.PublicKey().Type() {
|
|
return algorithmSignerWrapper{k}
|
|
}
|
|
|
|
k, ok := k.(AlgorithmSigner)
|
|
if !ok {
|
|
continue
|
|
}
|
|
for _, a := range algorithmsForKeyFormat(k.PublicKey().Type()) {
|
|
if algo == a {
|
|
return k
|
|
}
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (t *handshakeTransport) server(kex kexAlgorithm, magics *handshakeMagics) (*kexResult, error) {
|
|
hostKey := pickHostKey(t.hostKeys, t.algorithms.hostKey)
|
|
if hostKey == nil {
|
|
return nil, errors.New("ssh: internal error: negotiated unsupported signature type")
|
|
}
|
|
|
|
r, err := kex.Server(t.conn, t.config.Rand, magics, hostKey, t.algorithms.hostKey)
|
|
return r, err
|
|
}
|
|
|
|
func (t *handshakeTransport) client(kex kexAlgorithm, magics *handshakeMagics) (*kexResult, error) {
|
|
result, err := kex.Client(t.conn, t.config.Rand, magics)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
hostKey, err := ParsePublicKey(result.HostKey)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if err := verifyHostKeySignature(hostKey, t.algorithms.hostKey, result); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
err = t.hostKeyCallback(t.dialAddress, t.remoteAddr, hostKey)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return result, nil
|
|
}
|