opensource/podman
1
0
Fork 0
mirror of https://github.com/containers/podman.git synced 2025-05-21 17:16:22 +08:00
Code Issues Packages Projects Releases Wiki Activity

V2 Add support for ssh authentication methods

Browse Source 
* podman --remote ssh://<user>:<password>@<host>:<port><path>
* podman --remote ssh://<user>:<password>@<host>:<port><path> \
  --identity <path> --passphrase <phrase>
* ssh-add <key>
  podman --remote ssh://<user>@<host><path>
* Fix `podman help` to run even if podman missing components
* Prompt for passphrase on stdin IFF key is protected and passphrase
  not given via any other configuration

* cobra flags do not support optional value flags therefore refactored
  --remote to be a boolean and --url will now contain the URI to Podman
  service

Signed-off-by: Jhon Honce <jhonce@redhat.com>
This commit is contained in:
Jhon Honce
2020-06-02 11:46:24 -07:00
parent 9bd48a64bb
commit cbca625328
14 changed files with 1874 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
cmd/podman/root.go
View File

@ -103,6 +103,11 @@ func persistentPreRunE(cmd *cobra.Command, args []string) error {
cfg := registry.PodmanConfig()
// Help is a special case, no need for more setup
if cmd.Name() == "help" {
return nil
}
// Prep the engines
if _, err := registry.NewImageEngine(cmd, args); err != nil {
return err
@ -150,6 +155,11 @@ func persistentPostRunE(cmd *cobra.Command, args []string) error {
// TODO: Remove trace statement in podman V2.1
logrus.Debugf("Called %s.PersistentPostRunE(%s)", cmd.Name(), strings.Join(os.Args, " "))
// Help is a special case, no need for more cleanup
if cmd.Name() == "help" {
return nil
}
cfg := registry.PodmanConfig()
if cmd.Flag("cpu-profile").Changed {
pprof.StopCPUProfile()
@ -191,8 +201,11 @@ func loggingHook() {
func rootFlags(opts *entities.PodmanConfig, flags *pflag.FlagSet) {
// V2 flags
flags.StringVarP(&opts.Uri, "remote", "r", registry.DefaultAPIAddress(), "URL to access Podman service")
flags.StringSliceVar(&opts.Identities, "identity", []string{}, "path to SSH identity file")
flags.BoolVarP(&opts.Remote, "remote", "r", false, "Access remote Podman service (default false)")
// TODO Read uri from containers.config when available
flags.StringVar(&opts.Uri, "url", registry.DefaultAPIAddress(), "URL to access Podman service (CONTAINER_HOST)")
flags.StringSliceVar(&opts.Identities, "identity", []string{}, "path to SSH identity file, (CONTAINER_SSHKEY)")
flags.StringVar(&opts.PassPhrase, "passphrase", "", "passphrase for identity file (not secure, CONTAINER_PASSPHRASE), ssh-agent always supported")
cfg := opts.Config
flags.StringVar(&cfg.Engine.CgroupManager, "cgroup-manager", cfg.Engine.CgroupManager, "Cgroup manager to use (\"cgroupfs\"|\"systemd\")")

14
docs/source/markdown/podman.1.md
View File

@ -61,6 +61,9 @@ Podman and libpod currently support an additional `precreate` state which is cal
**--identity**=*path*
Path to SSH identity file
**--passphrase**=*secret*
pass phrase for SSH identity file
**--log-level**=*level*
Log messages above specified level: debug, info, warn, error (default), fatal or panic (default: "error")
@ -73,18 +76,21 @@ When namespace is set, created containers and pods will join the given namespace
**--network-cmd-path**=*path*
Path to the command binary to use for setting up a network. It is currently only used for setting up a slirp4netns network. If "" is used then the binary is looked up using the $PATH environment variable.
**--remote**, **-r**=*url*
URL to access Podman service (default "unix:/run/user/3267/podman/podman.sock")
**--remote**, **-r**
Access Podman service will be remote
**--url**=*value*
URL to access Podman service (default from `containers.conf`, rootless "unix://run/user/$UID/podman/podman.sock" or as root "unix://run/podman/podman.sock).
**--root**=*value*
Storage root dir in which data, including images, is stored (default: "/var/lib/containers/storage" for UID 0, "$HOME/.local/share/containers/storage" for other users).
Default root dir is configured in `/etc/containers/storage.conf`.
Default root dir configured in `/etc/containers/storage.conf`.
**--runroot**=*value*
Storage state directory where all state information is stored (default: "/var/run/containers/storage" for UID 0, "/var/run/user/$UID/run" for other users).
Default state dir is configured in `/etc/containers/storage.conf`.
Default state dir configured in `/etc/containers/storage.conf`.
**--runtime**=*value*

43
pkg/bindings/bindings.go
View File

@ -9,7 +9,13 @@
package bindings
import (
"errors"
"fmt"
"io"
"os"
"github.com/blang/semver"
"golang.org/x/crypto/ssh/terminal"
)
var (
@ -25,3 +31,40 @@ var (
// _*YES*- podman will fail to run if this value is wrong
APIVersion = semver.MustParse("1.0.0")
)
// readPassword prompts for a secret and returns value input by user from stdin
// Unlike terminal.ReadPassword(), $(echo $SECRET | podman...) is supported.
// Additionally, all input after `<secret>/n` is queued to podman command.
func readPassword(prompt string) (pw []byte, err error) {
fd := int(os.Stdin.Fd())
if terminal.IsTerminal(fd) {
fmt.Fprint(os.Stderr, prompt)
pw, err = terminal.ReadPassword(fd)
fmt.Fprintln(os.Stderr)
return
}
var b [1]byte
for {
n, err := os.Stdin.Read(b[:])
// terminal.ReadPassword discards any '\r', so we do the same
if n > 0 && b[0] != '\r' {
if b[0] == '\n' {
return pw, nil
}
pw = append(pw, b[0])
// limit size, so that a wrong input won't fill up the memory
if len(pw) > 1024 {
err = errors.New("password too long, 1024 byte limit")
}
}
if err != nil {
// terminal.ReadPassword accepts EOF-terminated passwords
// if non-empty, so we do the same
if err == io.EOF && len(pw) > 0 {
err = nil
}
return pw, err
}
}
}

80
pkg/bindings/connection.go
View File

@ -13,6 +13,7 @@ import (
"path/filepath"
"strconv"
"strings"
"sync"
"time"
"github.com/blang/semver"
@ -20,6 +21,7 @@ import (
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"golang.org/x/crypto/ssh"
"golang.org/x/crypto/ssh/agent"
"k8s.io/client-go/util/homedir"
)
@ -29,6 +31,8 @@ var (
Host: "d",
Path: "/v" + APIVersion.String() + "/libpod",
}
passPhrase []byte
phraseSync sync.Once
)
type APIResponse struct {
@ -61,6 +65,10 @@ func JoinURL(elements ...string) string {
return "/" + strings.Join(elements, "/")
}
func NewConnection(ctx context.Context, uri string) (context.Context, error) {
return NewConnectionWithIdentity(ctx, uri, "")
}
// NewConnection takes a URI as a string and returns a context with the
// Connection embedded as a value. This context needs to be passed to each
// endpoint to work correctly.
@ -69,23 +77,28 @@ func JoinURL(elements ...string) string {
// For example tcp://localhost:<port>
// or unix:///run/podman/podman.sock
// or ssh://<user>@<host>[:port]/run/podman/podman.sock?secure=True
func NewConnection(ctx context.Context, uri string, identity ...string) (context.Context, error) {
func NewConnectionWithIdentity(ctx context.Context, uri string, passPhrase string, identities ...string) (context.Context, error) {
var (
err error
secure bool
)
if v, found := os.LookupEnv("PODMAN_HOST"); found {
if v, found := os.LookupEnv("CONTAINER_HOST"); found && uri == "" {
uri = v
}
if v, found := os.LookupEnv("PODMAN_SSHKEY"); found {
identity = []string{v}
if v, found := os.LookupEnv("CONTAINER_SSHKEY"); found && len(identities) == 0 {
identities = append(identities, v)
}
if v, found := os.LookupEnv("CONTAINER_PASSPHRASE"); found && passPhrase == "" {
passPhrase = v
}
_url, err := url.Parse(uri)
if err != nil {
return nil, errors.Wrapf(err, "Value of PODMAN_HOST is not a valid url: %s", uri)
return nil, errors.Wrapf(err, "Value of CONTAINER_HOST is not a valid url: %s", uri)
}
// TODO Fill in missing defaults for _url...
// Now we setup the http Client to use the connection above
var connection Connection
@ -95,7 +108,7 @@ func NewConnection(ctx context.Context, uri string, identity ...string) (context
if err != nil {
secure = false
}
connection, err = sshClient(_url, identity[0], secure)
connection, err = sshClient(_url, secure, passPhrase, identities...)
case "unix":
if !strings.HasPrefix(uri, "unix:///") {
// autofix unix://path_element vs unix:///path_element
@ -172,10 +185,31 @@ func pingNewConnection(ctx context.Context) error {
return errors.Errorf("ping response was %q", response.StatusCode)
}
func sshClient(_url *url.URL, identity string, secure bool) (Connection, error) {
auth, err := publicKey(identity)
if err != nil {
return Connection{}, errors.Wrapf(err, "Failed to parse identity %s: %v\n", _url.String(), identity)
func sshClient(_url *url.URL, secure bool, passPhrase string, identities ...string) (Connection, error) {
var authMethods []ssh.AuthMethod
for _, i := range identities {
auth, err := publicKey(i, []byte(passPhrase))
if err != nil {
fmt.Fprint(os.Stderr, errors.Wrapf(err, "failed to parse identity %q", i).Error()+"\n")
continue
}
authMethods = append(authMethods, auth)
}
if sock, found := os.LookupEnv("SSH_AUTH_SOCK"); found {
logrus.Debugf("Found SSH_AUTH_SOCK %q, ssh-agent signer enabled", sock)
c, err := net.Dial("unix", sock)
if err != nil {
return Connection{}, err
}
a := agent.NewClient(c)
authMethods = append(authMethods, ssh.PublicKeysCallback(a.Signers))
}
if pw, found := _url.User.Password(); found {
authMethods = append(authMethods, ssh.Password(pw))
}
callback := ssh.InsecureIgnoreHostKey()
@ -195,7 +229,7 @@ func sshClient(_url *url.URL, identity string, secure bool) (Connection, error)
net.JoinHostPort(_url.Hostname(), port),
&ssh.ClientConfig{
User: _url.User.Username(),
Auth: []ssh.AuthMethod{auth},
Auth: authMethods,
HostKeyCallback: callback,
HostKeyAlgorithms: []string{
ssh.KeyAlgoRSA,
@ -307,7 +341,7 @@ func (h *APIResponse) IsServerError() bool {
return h.Response.StatusCode/100 == 5
}
func publicKey(path string) (ssh.AuthMethod, error) {
func publicKey(path string, passphrase []byte) (ssh.AuthMethod, error) {
key, err := ioutil.ReadFile(path)
if err != nil {
return nil, err
@ -315,12 +349,30 @@ func publicKey(path string) (ssh.AuthMethod, error) {
signer, err := ssh.ParsePrivateKey(key)
if err != nil {
return nil, err
if _, ok := err.(*ssh.PassphraseMissingError); !ok {
return nil, err
}
if len(passphrase) == 0 {
phraseSync.Do(promptPassphrase)
passphrase = passPhrase
}
signer, err = ssh.ParsePrivateKeyWithPassphrase(key, passphrase)
if err != nil {
return nil, err
}
}
return ssh.PublicKeys(signer), nil
}
func promptPassphrase() {
phrase, err := readPassword("Key Passphrase: ")
if err != nil {
passPhrase = []byte{}
return
}
passPhrase = phrase
}
func hostKey(host string) ssh.PublicKey {
// parse OpenSSH known_hosts file
// ssh or use ssh-keyscan to get initial key

6
pkg/domain/entities/engine.go
View File

@ -43,14 +43,16 @@ type PodmanConfig struct {
EngineMode EngineMode // ABI or Tunneling mode
Identities []string // ssh identities for connecting to server
MaxWorks int // maximum number of parallel threads
PassPhrase string // ssh passphrase for identity for connecting to server
RegistriesConf string // allows for specifying a custom registries.conf
Remote bool // Connection to Podman API Service will use RESTful API
RuntimePath string // --runtime flag will set Engine.RuntimePath
Span opentracing.Span // tracing object
SpanCloser io.Closer // Close() for tracing object
SpanCtx context.Context // context to use when tracing
Span opentracing.Span // tracing object
Syslog bool // write to StdOut and Syslog, not supported when tunneling
Trace bool // Hidden: Trace execution
Uri string // URI to API Service
Uri string // URI to RESTful API Service
Runroot string
StorageDriver string

4
pkg/domain/infra/runtime_abi.go
View File

@ -20,7 +20,7 @@ func NewContainerEngine(facts *entities.PodmanConfig) (entities.ContainerEngine,
r, err := NewLibpodRuntime(facts.FlagSet, facts)
return r, err
case entities.TunnelMode:
ctx, err := bindings.NewConnection(context.Background(), facts.Uri, facts.Identities...)
ctx, err := bindings.NewConnectionWithIdentity(context.Background(), facts.Uri, facts.PassPhrase, facts.Identities...)
return &tunnel.ContainerEngine{ClientCxt: ctx}, err
}
return nil, fmt.Errorf("runtime mode '%v' is not supported", facts.EngineMode)
@ -33,7 +33,7 @@ func NewImageEngine(facts *entities.PodmanConfig) (entities.ImageEngine, error)
r, err := NewLibpodImageRuntime(facts.FlagSet, facts)
return r, err
case entities.TunnelMode:
ctx, err := bindings.NewConnection(context.Background(), facts.Uri, facts.Identities...)
ctx, err := bindings.NewConnectionWithIdentity(context.Background(), facts.Uri, facts.PassPhrase, facts.Identities...)
return &tunnel.ImageEngine{ClientCxt: ctx}, err
}
return nil, fmt.Errorf("runtime mode '%v' is not supported", facts.EngineMode)

4
pkg/domain/infra/runtime_tunnel.go
View File

@ -16,7 +16,7 @@ func NewContainerEngine(facts *entities.PodmanConfig) (entities.ContainerEngine,
case entities.ABIMode:
return nil, fmt.Errorf("direct runtime not supported")
case entities.TunnelMode:
ctx, err := bindings.NewConnection(context.Background(), facts.Uri, facts.Identities...)
ctx, err := bindings.NewConnectionWithIdentity(context.Background(), facts.Uri, facts.PassPhrase, facts.Identities...)
return &tunnel.ContainerEngine{ClientCxt: ctx}, err
}
return nil, fmt.Errorf("runtime mode '%v' is not supported", facts.EngineMode)
@ -28,7 +28,7 @@ func NewImageEngine(facts *entities.PodmanConfig) (entities.ImageEngine, error)
case entities.ABIMode:
return nil, fmt.Errorf("direct image runtime not supported")
case entities.TunnelMode:
ctx, err := bindings.NewConnection(context.Background(), facts.Uri, facts.Identities...)
ctx, err := bindings.NewConnectionWithIdentity(context.Background(), facts.Uri, facts.PassPhrase, facts.Identities...)
return &tunnel.ImageEngine{ClientCxt: ctx}, err
}
return nil, fmt.Errorf("runtime mode '%v' is not supported", facts.EngineMode)

6
test/e2e/libpod_suite_remote_test.go
View File

@ -36,7 +36,7 @@ func SkipIfRootlessV2() {
// Podman is the exec call to podman on the filesystem
func (p *PodmanTestIntegration) Podman(args []string) *PodmanSessionIntegration {
var remoteArgs = []string{"--remote", p.RemoteSocket}
var remoteArgs = []string{"--remote", "--url", p.RemoteSocket}
remoteArgs = append(remoteArgs, args...)
podmanSession := p.PodmanBase(remoteArgs, false, false)
return &PodmanSessionIntegration{podmanSession}
@ -44,7 +44,7 @@ func (p *PodmanTestIntegration) Podman(args []string) *PodmanSessionIntegration
// PodmanExtraFiles is the exec call to podman on the filesystem and passes down extra files
func (p *PodmanTestIntegration) PodmanExtraFiles(args []string, extraFiles []*os.File) *PodmanSessionIntegration {
var remoteArgs = []string{"--remote", p.RemoteSocket}
var remoteArgs = []string{"--remote", "--url", p.RemoteSocket}
remoteArgs = append(remoteArgs, args...)
podmanSession := p.PodmanAsUserBase(remoteArgs, 0, 0, "", nil, false, false, extraFiles)
return &PodmanSessionIntegration{podmanSession}
@ -52,7 +52,7 @@ func (p *PodmanTestIntegration) PodmanExtraFiles(args []string, extraFiles []*os
// PodmanNoCache calls podman with out adding the imagecache
func (p *PodmanTestIntegration) PodmanNoCache(args []string) *PodmanSessionIntegration {
var remoteArgs = []string{"--remote", p.RemoteSocket}
var remoteArgs = []string{"--remote", "--url", p.RemoteSocket}
remoteArgs = append(remoteArgs, args...)
podmanSession := p.PodmanBase(remoteArgs, false, true)
return &PodmanSessionIntegration{podmanSession}

2
test/utils/utils.go
View File

@ -73,7 +73,7 @@ func (p *PodmanTest) PodmanAsUserBase(args []string, uid, gid uint32, cwd string
podmanBinary = p.RemotePodmanBinary
}
if p.RemoteTest {
podmanOptions = append([]string{"--remote", p.RemoteSocket}, podmanOptions...)
podmanOptions = append([]string{"--remote", "--url", p.RemoteSocket}, podmanOptions...)
}
if env == nil {
fmt.Printf("Running: %s %s\n", podmanBinary, strings.Join(podmanOptions, " "))

813
vendor/golang.org/x/crypto/ssh/agent/client.go generated vendored Normal file
View File

@ -0,0 +1,813 @@
// Copyright 2012 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 agent implements the ssh-agent protocol, and provides both
// a client and a server. The client can talk to a standard ssh-agent
// that uses UNIX sockets, and one could implement an alternative
// ssh-agent process using the sample server.
//
// References:
// [PROTOCOL.agent]: https://tools.ietf.org/html/draft-miller-ssh-agent-00
package agent // import "golang.org/x/crypto/ssh/agent"
import (
"bytes"
"crypto/dsa"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rsa"
"encoding/base64"
"encoding/binary"
"errors"
"fmt"
"io"
"math/big"
"sync"
"crypto"
"golang.org/x/crypto/ed25519"
"golang.org/x/crypto/ssh"
)
// SignatureFlags represent additional flags that can be passed to the signature
// requests an defined in [PROTOCOL.agent] section 4.5.1.
type SignatureFlags uint32
// SignatureFlag values as defined in [PROTOCOL.agent] section 5.3.
const (
SignatureFlagReserved SignatureFlags = 1 << iota
SignatureFlagRsaSha256
SignatureFlagRsaSha512
)
// Agent represents the capabilities of an ssh-agent.
type Agent interface {
// List returns the identities known to the agent.
List() ([]*Key, error)
// Sign has the agent sign the data using a protocol 2 key as defined
// in [PROTOCOL.agent] section 2.6.2.
Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error)
// Add adds a private key to the agent.
Add(key AddedKey) error
// Remove removes all identities with the given public key.
Remove(key ssh.PublicKey) error
// RemoveAll removes all identities.
RemoveAll() error
// Lock locks the agent. Sign and Remove will fail, and List will empty an empty list.
Lock(passphrase []byte) error
// Unlock undoes the effect of Lock
Unlock(passphrase []byte) error
// Signers returns signers for all the known keys.
Signers() ([]ssh.Signer, error)
}
type ExtendedAgent interface {
Agent
// SignWithFlags signs like Sign, but allows for additional flags to be sent/received
SignWithFlags(key ssh.PublicKey, data []byte, flags SignatureFlags) (*ssh.Signature, error)
// Extension processes a custom extension request. Standard-compliant agents are not
// required to support any extensions, but this method allows agents to implement
// vendor-specific methods or add experimental features. See [PROTOCOL.agent] section 4.7.
// If agent extensions are unsupported entirely this method MUST return an
// ErrExtensionUnsupported error. Similarly, if just the specific extensionType in
// the request is unsupported by the agent then ErrExtensionUnsupported MUST be
// returned.
//
// In the case of success, since [PROTOCOL.agent] section 4.7 specifies that the contents
// of the response are unspecified (including the type of the message), the complete
// response will be returned as a []byte slice, including the "type" byte of the message.
Extension(extensionType string, contents []byte) ([]byte, error)
}
// ConstraintExtension describes an optional constraint defined by users.
type ConstraintExtension struct {
// ExtensionName consist of a UTF-8 string suffixed by the
// implementation domain following the naming scheme defined
// in Section 4.2 of [RFC4251], e.g. "foo@example.com".
ExtensionName string
// ExtensionDetails contains the actual content of the extended
// constraint.
ExtensionDetails []byte
}
// AddedKey describes an SSH key to be added to an Agent.
type AddedKey struct {
// PrivateKey must be a *rsa.PrivateKey, *dsa.PrivateKey,
// ed25519.PrivateKey or *ecdsa.PrivateKey, which will be inserted into the
// agent.
PrivateKey interface{}
// Certificate, if not nil, is communicated to the agent and will be
// stored with the key.
Certificate *ssh.Certificate
// Comment is an optional, free-form string.
Comment string
// LifetimeSecs, if not zero, is the number of seconds that the
// agent will store the key for.
LifetimeSecs uint32
// ConfirmBeforeUse, if true, requests that the agent confirm with the
// user before each use of this key.
ConfirmBeforeUse bool
// ConstraintExtensions are the experimental or private-use constraints
// defined by users.
ConstraintExtensions []ConstraintExtension
}
// See [PROTOCOL.agent], section 3.
const (
agentRequestV1Identities = 1
agentRemoveAllV1Identities = 9
// 3.2 Requests from client to agent for protocol 2 key operations
agentAddIdentity = 17
agentRemoveIdentity = 18
agentRemoveAllIdentities = 19
agentAddIDConstrained = 25
// 3.3 Key-type independent requests from client to agent
agentAddSmartcardKey = 20
agentRemoveSmartcardKey = 21
agentLock = 22
agentUnlock = 23
agentAddSmartcardKeyConstrained = 26
// 3.7 Key constraint identifiers
agentConstrainLifetime = 1
agentConstrainConfirm = 2
agentConstrainExtension = 3
)
// maxAgentResponseBytes is the maximum agent reply size that is accepted. This
// is a sanity check, not a limit in the spec.
const maxAgentResponseBytes = 16 << 20
// Agent messages:
// These structures mirror the wire format of the corresponding ssh agent
// messages found in [PROTOCOL.agent].
// 3.4 Generic replies from agent to client
const agentFailure = 5
type failureAgentMsg struct{}
const agentSuccess = 6
type successAgentMsg struct{}
// See [PROTOCOL.agent], section 2.5.2.
const agentRequestIdentities = 11
type requestIdentitiesAgentMsg struct{}
// See [PROTOCOL.agent], section 2.5.2.
const agentIdentitiesAnswer = 12
type identitiesAnswerAgentMsg struct {
NumKeys uint32 `sshtype:"12"`
Keys []byte `ssh:"rest"`
}
// See [PROTOCOL.agent], section 2.6.2.
const agentSignRequest = 13
type signRequestAgentMsg struct {
KeyBlob []byte `sshtype:"13"`
Data []byte
Flags uint32
}
// See [PROTOCOL.agent], section 2.6.2.
// 3.6 Replies from agent to client for protocol 2 key operations
const agentSignResponse = 14
type signResponseAgentMsg struct {
SigBlob []byte `sshtype:"14"`
}
type publicKey struct {
Format string
Rest []byte `ssh:"rest"`
}
// 3.7 Key constraint identifiers
type constrainLifetimeAgentMsg struct {
LifetimeSecs uint32 `sshtype:"1"`
}
type constrainExtensionAgentMsg struct {
ExtensionName string `sshtype:"3"`
ExtensionDetails []byte
// Rest is a field used for parsing, not part of message
Rest []byte `ssh:"rest"`
}
// See [PROTOCOL.agent], section 4.7
const agentExtension = 27
const agentExtensionFailure = 28
// ErrExtensionUnsupported indicates that an extension defined in
// [PROTOCOL.agent] section 4.7 is unsupported by the agent. Specifically this
// error indicates that the agent returned a standard SSH_AGENT_FAILURE message
// as the result of a SSH_AGENTC_EXTENSION request. Note that the protocol
// specification (and therefore this error) does not distinguish between a
// specific extension being unsupported and extensions being unsupported entirely.
var ErrExtensionUnsupported = errors.New("agent: extension unsupported")
type extensionAgentMsg struct {
ExtensionType string `sshtype:"27"`
Contents []byte
}
// Key represents a protocol 2 public key as defined in
// [PROTOCOL.agent], section 2.5.2.
type Key struct {
Format string
Blob []byte
Comment string
}
func clientErr(err error) error {
return fmt.Errorf("agent: client error: %v", err)
}
// String returns the storage form of an agent key with the format, base64
// encoded serialized key, and the comment if it is not empty.
func (k *Key) String() string {
s := string(k.Format) + " " + base64.StdEncoding.EncodeToString(k.Blob)
if k.Comment != "" {
s += " " + k.Comment
}
return s
}
// Type returns the public key type.
func (k *Key) Type() string {
return k.Format
}
// Marshal returns key blob to satisfy the ssh.PublicKey interface.
func (k *Key) Marshal() []byte {
return k.Blob
}
// Verify satisfies the ssh.PublicKey interface.
func (k *Key) Verify(data []byte, sig *ssh.Signature) error {
pubKey, err := ssh.ParsePublicKey(k.Blob)
if err != nil {
return fmt.Errorf("agent: bad public key: %v", err)
}
return pubKey.Verify(data, sig)
}
type wireKey struct {
Format string
Rest []byte `ssh:"rest"`
}
func parseKey(in []byte) (out *Key, rest []byte, err error) {
var record struct {
Blob []byte
Comment string
Rest []byte `ssh:"rest"`
}
if err := ssh.Unmarshal(in, &record); err != nil {
return nil, nil, err
}
var wk wireKey
if err := ssh.Unmarshal(record.Blob, &wk); err != nil {
return nil, nil, err
}
return &Key{
Format: wk.Format,
Blob: record.Blob,
Comment: record.Comment,
}, record.Rest, nil
}
// client is a client for an ssh-agent process.
type client struct {
// conn is typically a *net.UnixConn
conn io.ReadWriter
// mu is used to prevent concurrent access to the agent
mu sync.Mutex
}
// NewClient returns an Agent that talks to an ssh-agent process over
// the given connection.
func NewClient(rw io.ReadWriter) ExtendedAgent {
return &client{conn: rw}
}
// call sends an RPC to the agent. On success, the reply is
// unmarshaled into reply and replyType is set to the first byte of
// the reply, which contains the type of the message.
func (c *client) call(req []byte) (reply interface{}, err error) {
buf, err := c.callRaw(req)
if err != nil {
return nil, err
}
reply, err = unmarshal(buf)
if err != nil {
return nil, clientErr(err)
}
return reply, nil
}
// callRaw sends an RPC to the agent. On success, the raw
// bytes of the response are returned; no unmarshalling is
// performed on the response.
func (c *client) callRaw(req []byte) (reply []byte, err error) {
c.mu.Lock()
defer c.mu.Unlock()
msg := make([]byte, 4+len(req))
binary.BigEndian.PutUint32(msg, uint32(len(req)))
copy(msg[4:], req)
if _, err = c.conn.Write(msg); err != nil {
return nil, clientErr(err)
}
var respSizeBuf [4]byte
if _, err = io.ReadFull(c.conn, respSizeBuf[:]); err != nil {
return nil, clientErr(err)
}
respSize := binary.BigEndian.Uint32(respSizeBuf[:])
if respSize > maxAgentResponseBytes {
return nil, clientErr(errors.New("response too large"))
}
buf := make([]byte, respSize)
if _, err = io.ReadFull(c.conn, buf); err != nil {
return nil, clientErr(err)
}
return buf, nil
}
func (c *client) simpleCall(req []byte) error {
resp, err := c.call(req)
if err != nil {
return err
}
if _, ok := resp.(*successAgentMsg); ok {
return nil
}
return errors.New("agent: failure")
}
func (c *client) RemoveAll() error {
return c.simpleCall([]byte{agentRemoveAllIdentities})
}
func (c *client) Remove(key ssh.PublicKey) error {
req := ssh.Marshal(&agentRemoveIdentityMsg{
KeyBlob: key.Marshal(),
})
return c.simpleCall(req)
}
func (c *client) Lock(passphrase []byte) error {
req := ssh.Marshal(&agentLockMsg{
Passphrase: passphrase,
})
return c.simpleCall(req)
}
func (c *client) Unlock(passphrase []byte) error {
req := ssh.Marshal(&agentUnlockMsg{
Passphrase: passphrase,
})
return c.simpleCall(req)
}
// List returns the identities known to the agent.
func (c *client) List() ([]*Key, error) {
// see [PROTOCOL.agent] section 2.5.2.
req := []byte{agentRequestIdentities}
msg, err := c.call(req)
if err != nil {
return nil, err
}
switch msg := msg.(type) {
case *identitiesAnswerAgentMsg:
if msg.NumKeys > maxAgentResponseBytes/8 {
return nil, errors.New("agent: too many keys in agent reply")
}
keys := make([]*Key, msg.NumKeys)
data := msg.Keys
for i := uint32(0); i < msg.NumKeys; i++ {
var key *Key
var err error
if key, data, err = parseKey(data); err != nil {
return nil, err
}
keys[i] = key
}
return keys, nil
case *failureAgentMsg:
return nil, errors.New("agent: failed to list keys")
}
panic("unreachable")
}
// Sign has the agent sign the data using a protocol 2 key as defined
// in [PROTOCOL.agent] section 2.6.2.
func (c *client) Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error) {
return c.SignWithFlags(key, data, 0)
}
func (c *client) SignWithFlags(key ssh.PublicKey, data []byte, flags SignatureFlags) (*ssh.Signature, error) {
req := ssh.Marshal(signRequestAgentMsg{
KeyBlob: key.Marshal(),
Data: data,
Flags: uint32(flags),
})
msg, err := c.call(req)
if err != nil {
return nil, err
}
switch msg := msg.(type) {
case *signResponseAgentMsg:
var sig ssh.Signature
if err := ssh.Unmarshal(msg.SigBlob, &sig); err != nil {
return nil, err
}
return &sig, nil
case *failureAgentMsg:
return nil, errors.New("agent: failed to sign challenge")
}
panic("unreachable")
}
// unmarshal parses an agent message in packet, returning the parsed
// form and the message type of packet.
func unmarshal(packet []byte) (interface{}, error) {
if len(packet) < 1 {
return nil, errors.New("agent: empty packet")
}
var msg interface{}
switch packet[0] {
case agentFailure:
return new(failureAgentMsg), nil
case agentSuccess:
return new(successAgentMsg), nil
case agentIdentitiesAnswer:
msg = new(identitiesAnswerAgentMsg)
case agentSignResponse:
msg = new(signResponseAgentMsg)
case agentV1IdentitiesAnswer:
msg = new(agentV1IdentityMsg)
default:
return nil, fmt.Errorf("agent: unknown type tag %d", packet[0])
}
if err := ssh.Unmarshal(packet, msg); err != nil {
return nil, err
}
return msg, nil
}
type rsaKeyMsg struct {
Type string `sshtype:"17|25"`
N *big.Int
E *big.Int
D *big.Int
Iqmp *big.Int // IQMP = Inverse Q Mod P
P *big.Int
Q *big.Int
Comments string
Constraints []byte `ssh:"rest"`
}
type dsaKeyMsg struct {
Type string `sshtype:"17|25"`
P *big.Int
Q *big.Int
G *big.Int
Y *big.Int
X *big.Int
Comments string
Constraints []byte `ssh:"rest"`
}
type ecdsaKeyMsg struct {
Type string `sshtype:"17|25"`
Curve string
KeyBytes []byte
D *big.Int
Comments string
Constraints []byte `ssh:"rest"`
}
type ed25519KeyMsg struct {
Type string `sshtype:"17|25"`
Pub []byte
Priv []byte
Comments string
Constraints []byte `ssh:"rest"`
}
// Insert adds a private key to the agent.
func (c *client) insertKey(s interface{}, comment string, constraints []byte) error {
var req []byte
switch k := s.(type) {
case *rsa.PrivateKey:
if len(k.Primes) != 2 {
return fmt.Errorf("agent: unsupported RSA key with %d primes", len(k.Primes))
}
k.Precompute()
req = ssh.Marshal(rsaKeyMsg{
Type: ssh.KeyAlgoRSA,
N: k.N,
E: big.NewInt(int64(k.E)),
D: k.D,
Iqmp: k.Precomputed.Qinv,
P: k.Primes[0],
Q: k.Primes[1],
Comments: comment,
Constraints: constraints,
})
case *dsa.PrivateKey:
req = ssh.Marshal(dsaKeyMsg{
Type: ssh.KeyAlgoDSA,
P: k.P,
Q: k.Q,
G: k.G,
Y: k.Y,
X: k.X,
Comments: comment,
Constraints: constraints,
})
case *ecdsa.PrivateKey:
nistID := fmt.Sprintf("nistp%d", k.Params().BitSize)
req = ssh.Marshal(ecdsaKeyMsg{
Type: "ecdsa-sha2-" + nistID,
Curve: nistID,
KeyBytes: elliptic.Marshal(k.Curve, k.X, k.Y),
D: k.D,
Comments: comment,
Constraints: constraints,
})
case ed25519.PrivateKey:
req = ssh.Marshal(ed25519KeyMsg{
Type: ssh.KeyAlgoED25519,
Pub: []byte(k)[32:],
Priv: []byte(k),
Comments: comment,
Constraints: constraints,
})
// This function originally supported only *ed25519.PrivateKey, however the
// general idiom is to pass ed25519.PrivateKey by value, not by pointer.
// We still support the pointer variant for backwards compatibility.
case *ed25519.PrivateKey:
req = ssh.Marshal(ed25519KeyMsg{
Type: ssh.KeyAlgoED25519,
Pub: []byte(*k)[32:],
Priv: []byte(*k),
Comments: comment,
Constraints: constraints,
})
default:
return fmt.Errorf("agent: unsupported key type %T", s)
}
// if constraints are present then the message type needs to be changed.
if len(constraints) != 0 {
req[0] = agentAddIDConstrained
}
resp, err := c.call(req)
if err != nil {
return err
}
if _, ok := resp.(*successAgentMsg); ok {
return nil
}
return errors.New("agent: failure")
}
type rsaCertMsg struct {
Type string `sshtype:"17|25"`
CertBytes []byte
D *big.Int
Iqmp *big.Int // IQMP = Inverse Q Mod P
P *big.Int
Q *big.Int
Comments string
Constraints []byte `ssh:"rest"`
}
type dsaCertMsg struct {
Type string `sshtype:"17|25"`
CertBytes []byte
X *big.Int
Comments string
Constraints []byte `ssh:"rest"`
}
type ecdsaCertMsg struct {
Type string `sshtype:"17|25"`
CertBytes []byte
D *big.Int
Comments string
Constraints []byte `ssh:"rest"`
}
type ed25519CertMsg struct {
Type string `sshtype:"17|25"`
CertBytes []byte
Pub []byte
Priv []byte
Comments string
Constraints []byte `ssh:"rest"`
}
// Add adds a private key to the agent. If a certificate is given,
// that certificate is added instead as public key.
func (c *client) Add(key AddedKey) error {
var constraints []byte
if secs := key.LifetimeSecs; secs != 0 {
constraints = append(constraints, ssh.Marshal(constrainLifetimeAgentMsg{secs})...)
}
if key.ConfirmBeforeUse {
constraints = append(constraints, agentConstrainConfirm)
}
cert := key.Certificate
if cert == nil {
return c.insertKey(key.PrivateKey, key.Comment, constraints)
}
return c.insertCert(key.PrivateKey, cert, key.Comment, constraints)
}
func (c *client) insertCert(s interface{}, cert *ssh.Certificate, comment string, constraints []byte) error {
var req []byte
switch k := s.(type) {
case *rsa.PrivateKey:
if len(k.Primes) != 2 {
return fmt.Errorf("agent: unsupported RSA key with %d primes", len(k.Primes))
}
k.Precompute()
req = ssh.Marshal(rsaCertMsg{
Type: cert.Type(),
CertBytes: cert.Marshal(),
D: k.D,
Iqmp: k.Precomputed.Qinv,
P: k.Primes[0],
Q: k.Primes[1],
Comments: comment,
Constraints: constraints,
})
case *dsa.PrivateKey:
req = ssh.Marshal(dsaCertMsg{
Type: cert.Type(),
CertBytes: cert.Marshal(),
X: k.X,
Comments: comment,
Constraints: constraints,
})
case *ecdsa.PrivateKey:
req = ssh.Marshal(ecdsaCertMsg{
Type: cert.Type(),
CertBytes: cert.Marshal(),
D: k.D,
Comments: comment,
Constraints: constraints,
})
case ed25519.PrivateKey:
req = ssh.Marshal(ed25519CertMsg{
Type: cert.Type(),
CertBytes: cert.Marshal(),
Pub: []byte(k)[32:],
Priv: []byte(k),
Comments: comment,
Constraints: constraints,
})
// This function originally supported only *ed25519.PrivateKey, however the
// general idiom is to pass ed25519.PrivateKey by value, not by pointer.
// We still support the pointer variant for backwards compatibility.
case *ed25519.PrivateKey:
req = ssh.Marshal(ed25519CertMsg{
Type: cert.Type(),
CertBytes: cert.Marshal(),
Pub: []byte(*k)[32:],
Priv: []byte(*k),
Comments: comment,
Constraints: constraints,
})
default:
return fmt.Errorf("agent: unsupported key type %T", s)
}
// if constraints are present then the message type needs to be changed.
if len(constraints) != 0 {
req[0] = agentAddIDConstrained
}
signer, err := ssh.NewSignerFromKey(s)
if err != nil {
return err
}
if bytes.Compare(cert.Key.Marshal(), signer.PublicKey().Marshal()) != 0 {
return errors.New("agent: signer and cert have different public key")
}
resp, err := c.call(req)
if err != nil {
return err
}
if _, ok := resp.(*successAgentMsg); ok {
return nil
}
return errors.New("agent: failure")
}
// Signers provides a callback for client authentication.
func (c *client) Signers() ([]ssh.Signer, error) {
keys, err := c.List()
if err != nil {
return nil, err
}
var result []ssh.Signer
for _, k := range keys {
result = append(result, &agentKeyringSigner{c, k})
}
return result, nil
}
type agentKeyringSigner struct {
agent *client
pub ssh.PublicKey
}
func (s *agentKeyringSigner) PublicKey() ssh.PublicKey {
return s.pub
}
func (s *agentKeyringSigner) Sign(rand io.Reader, data []byte) (*ssh.Signature, error) {
// The agent has its own entropy source, so the rand argument is ignored.
return s.agent.Sign(s.pub, data)
}
func (s *agentKeyringSigner) SignWithOpts(rand io.Reader, data []byte, opts crypto.SignerOpts) (*ssh.Signature, error) {
var flags SignatureFlags
if opts != nil {
switch opts.HashFunc() {
case crypto.SHA256:
flags = SignatureFlagRsaSha256
case crypto.SHA512:
flags = SignatureFlagRsaSha512
}
}
return s.agent.SignWithFlags(s.pub, data, flags)
}
// Calls an extension method. It is up to the agent implementation as to whether or not
// any particular extension is supported and may always return an error. Because the
// type of the response is up to the implementation, this returns the bytes of the
// response and does not attempt any type of unmarshalling.
func (c *client) Extension(extensionType string, contents []byte) ([]byte, error) {
req := ssh.Marshal(extensionAgentMsg{
ExtensionType: extensionType,
Contents: contents,
})
buf, err := c.callRaw(req)
if err != nil {
return nil, err
}
if len(buf) == 0 {
return nil, errors.New("agent: failure; empty response")
}
// [PROTOCOL.agent] section 4.7 indicates that an SSH_AGENT_FAILURE message
// represents an agent that does not support the extension
if buf[0] == agentFailure {
return nil, ErrExtensionUnsupported
}
if buf[0] == agentExtensionFailure {
return nil, errors.New("agent: generic extension failure")
}
return buf, nil
}

103
vendor/golang.org/x/crypto/ssh/agent/forward.go generated vendored Normal file
View File

@ -0,0 +1,103 @@
// Copyright 2014 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 agent
import (
"errors"
"io"
"net"
"sync"
"golang.org/x/crypto/ssh"
)
// RequestAgentForwarding sets up agent forwarding for the session.
// ForwardToAgent or ForwardToRemote should be called to route
// the authentication requests.
func RequestAgentForwarding(session *ssh.Session) error {
ok, err := session.SendRequest("auth-agent-req@openssh.com", true, nil)
if err != nil {
return err
}
if !ok {
return errors.New("forwarding request denied")
}
return nil
}
// ForwardToAgent routes authentication requests to the given keyring.
func ForwardToAgent(client *ssh.Client, keyring Agent) error {
channels := client.HandleChannelOpen(channelType)
if channels == nil {
return errors.New("agent: already have handler for " + channelType)
}
go func() {
for ch := range channels {
channel, reqs, err := ch.Accept()
if err != nil {
continue
}
go ssh.DiscardRequests(reqs)
go func() {
ServeAgent(keyring, channel)
channel.Close()
}()
}
}()
return nil
}
const channelType = "auth-agent@openssh.com"
// ForwardToRemote routes authentication requests to the ssh-agent
// process serving on the given unix socket.
func ForwardToRemote(client *ssh.Client, addr string) error {
channels := client.HandleChannelOpen(channelType)
if channels == nil {
return errors.New("agent: already have handler for " + channelType)
}
conn, err := net.Dial("unix", addr)
if err != nil {
return err
}
conn.Close()
go func() {
for ch := range channels {
channel, reqs, err := ch.Accept()
if err != nil {
continue
}
go ssh.DiscardRequests(reqs)
go forwardUnixSocket(channel, addr)
}
}()
return nil
}
func forwardUnixSocket(channel ssh.Channel, addr string) {
conn, err := net.Dial("unix", addr)
if err != nil {
return
}
var wg sync.WaitGroup
wg.Add(2)
go func() {
io.Copy(conn, channel)
conn.(*net.UnixConn).CloseWrite()
wg.Done()
}()
go func() {
io.Copy(channel, conn)
channel.CloseWrite()
wg.Done()
}()
wg.Wait()
conn.Close()
channel.Close()
}

241
vendor/golang.org/x/crypto/ssh/agent/keyring.go generated vendored Normal file
View File

@ -0,0 +1,241 @@
// Copyright 2014 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 agent
import (
"bytes"
"crypto/rand"
"crypto/subtle"
"errors"
"fmt"
"sync"
"time"
"golang.org/x/crypto/ssh"
)
type privKey struct {
signer ssh.Signer
comment string
expire *time.Time
}
type keyring struct {
mu sync.Mutex
keys []privKey
locked bool
passphrase []byte
}
var errLocked = errors.New("agent: locked")
// NewKeyring returns an Agent that holds keys in memory. It is safe
// for concurrent use by multiple goroutines.
func NewKeyring() Agent {
return &keyring{}
}
// RemoveAll removes all identities.
func (r *keyring) RemoveAll() error {
r.mu.Lock()
defer r.mu.Unlock()
if r.locked {
return errLocked
}
r.keys = nil
return nil
}
// removeLocked does the actual key removal. The caller must already be holding the
// keyring mutex.
func (r *keyring) removeLocked(want []byte) error {
found := false
for i := 0; i < len(r.keys); {
if bytes.Equal(r.keys[i].signer.PublicKey().Marshal(), want) {
found = true
r.keys[i] = r.keys[len(r.keys)-1]
r.keys = r.keys[:len(r.keys)-1]
continue
} else {
i++
}
}
if !found {
return errors.New("agent: key not found")
}
return nil
}
// Remove removes all identities with the given public key.
func (r *keyring) Remove(key ssh.PublicKey) error {
r.mu.Lock()
defer r.mu.Unlock()
if r.locked {
return errLocked
}
return r.removeLocked(key.Marshal())
}
// Lock locks the agent. Sign and Remove will fail, and List will return an empty list.
func (r *keyring) Lock(passphrase []byte) error {
r.mu.Lock()
defer r.mu.Unlock()
if r.locked {
return errLocked
}
r.locked = true
r.passphrase = passphrase
return nil
}
// Unlock undoes the effect of Lock
func (r *keyring) Unlock(passphrase []byte) error {
r.mu.Lock()
defer r.mu.Unlock()
if !r.locked {
return errors.New("agent: not locked")
}
if 1 != subtle.ConstantTimeCompare(passphrase, r.passphrase) {
return fmt.Errorf("agent: incorrect passphrase")
}
r.locked = false
r.passphrase = nil
return nil
}
// expireKeysLocked removes expired keys from the keyring. If a key was added
// with a lifetimesecs contraint and seconds >= lifetimesecs seconds have
// ellapsed, it is removed. The caller *must* be holding the keyring mutex.
func (r *keyring) expireKeysLocked() {
for _, k := range r.keys {
if k.expire != nil && time.Now().After(*k.expire) {
r.removeLocked(k.signer.PublicKey().Marshal())
}
}
}
// List returns the identities known to the agent.
func (r *keyring) List() ([]*Key, error) {
r.mu.Lock()
defer r.mu.Unlock()
if r.locked {
// section 2.7: locked agents return empty.
return nil, nil
}
r.expireKeysLocked()
var ids []*Key
for _, k := range r.keys {
pub := k.signer.PublicKey()
ids = append(ids, &Key{
Format: pub.Type(),
Blob: pub.Marshal(),
Comment: k.comment})
}
return ids, nil
}
// Insert adds a private key to the keyring. If a certificate
// is given, that certificate is added as public key. Note that
// any constraints given are ignored.
func (r *keyring) Add(key AddedKey) error {
r.mu.Lock()
defer r.mu.Unlock()
if r.locked {
return errLocked
}
signer, err := ssh.NewSignerFromKey(key.PrivateKey)
if err != nil {
return err
}
if cert := key.Certificate; cert != nil {
signer, err = ssh.NewCertSigner(cert, signer)
if err != nil {
return err
}
}
p := privKey{
signer: signer,
comment: key.Comment,
}
if key.LifetimeSecs > 0 {
t := time.Now().Add(time.Duration(key.LifetimeSecs) * time.Second)
p.expire = &t
}
r.keys = append(r.keys, p)
return nil
}
// Sign returns a signature for the data.
func (r *keyring) Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error) {
return r.SignWithFlags(key, data, 0)
}
func (r *keyring) SignWithFlags(key ssh.PublicKey, data []byte, flags SignatureFlags) (*ssh.Signature, error) {
r.mu.Lock()
defer r.mu.Unlock()
if r.locked {
return nil, errLocked
}
r.expireKeysLocked()
wanted := key.Marshal()
for _, k := range r.keys {
if bytes.Equal(k.signer.PublicKey().Marshal(), wanted) {
if flags == 0 {
return k.signer.Sign(rand.Reader, data)
} else {
if algorithmSigner, ok := k.signer.(ssh.AlgorithmSigner); !ok {
return nil, fmt.Errorf("agent: signature does not support non-default signature algorithm: %T", k.signer)
} else {
var algorithm string
switch flags {
case SignatureFlagRsaSha256:
algorithm = ssh.SigAlgoRSASHA2256
case SignatureFlagRsaSha512:
algorithm = ssh.SigAlgoRSASHA2512
default:
return nil, fmt.Errorf("agent: unsupported signature flags: %d", flags)
}
return algorithmSigner.SignWithAlgorithm(rand.Reader, data, algorithm)
}
}
}
}
return nil, errors.New("not found")
}
// Signers returns signers for all the known keys.
func (r *keyring) Signers() ([]ssh.Signer, error) {
r.mu.Lock()
defer r.mu.Unlock()
if r.locked {
return nil, errLocked
}
r.expireKeysLocked()
s := make([]ssh.Signer, 0, len(r.keys))
for _, k := range r.keys {
s = append(s, k.signer)
}
return s, nil
}
// The keyring does not support any extensions
func (r *keyring) Extension(extensionType string, contents []byte) ([]byte, error) {
return nil, ErrExtensionUnsupported
}

570
vendor/golang.org/x/crypto/ssh/agent/server.go generated vendored Normal file
View File

@ -0,0 +1,570 @@
// Copyright 2012 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 agent
import (
"crypto/dsa"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rsa"
"encoding/binary"
"errors"
"fmt"
"io"
"log"
"math/big"
"golang.org/x/crypto/ed25519"
"golang.org/x/crypto/ssh"
)
// Server wraps an Agent and uses it to implement the agent side of
// the SSH-agent, wire protocol.
type server struct {
agent Agent
}
func (s *server) processRequestBytes(reqData []byte) []byte {
rep, err := s.processRequest(reqData)
if err != nil {
if err != errLocked {
// TODO(hanwen): provide better logging interface?
log.Printf("agent %d: %v", reqData[0], err)
}
return []byte{agentFailure}
}
if err == nil && rep == nil {
return []byte{agentSuccess}
}
return ssh.Marshal(rep)
}
func marshalKey(k *Key) []byte {
var record struct {
Blob []byte
Comment string
}
record.Blob = k.Marshal()
record.Comment = k.Comment
return ssh.Marshal(&record)
}
// See [PROTOCOL.agent], section 2.5.1.
const agentV1IdentitiesAnswer = 2
type agentV1IdentityMsg struct {
Numkeys uint32 `sshtype:"2"`
}
type agentRemoveIdentityMsg struct {
KeyBlob []byte `sshtype:"18"`
}
type agentLockMsg struct {
Passphrase []byte `sshtype:"22"`
}
type agentUnlockMsg struct {
Passphrase []byte `sshtype:"23"`
}
func (s *server) processRequest(data []byte) (interface{}, error) {
switch data[0] {
case agentRequestV1Identities:
return &agentV1IdentityMsg{0}, nil
case agentRemoveAllV1Identities:
return nil, nil
case agentRemoveIdentity:
var req agentRemoveIdentityMsg
if err := ssh.Unmarshal(data, &req); err != nil {
return nil, err
}
var wk wireKey
if err := ssh.Unmarshal(req.KeyBlob, &wk); err != nil {
return nil, err
}
return nil, s.agent.Remove(&Key{Format: wk.Format, Blob: req.KeyBlob})
case agentRemoveAllIdentities:
return nil, s.agent.RemoveAll()
case agentLock:
var req agentLockMsg
if err := ssh.Unmarshal(data, &req); err != nil {
return nil, err
}
return nil, s.agent.Lock(req.Passphrase)
case agentUnlock:
var req agentUnlockMsg
if err := ssh.Unmarshal(data, &req); err != nil {
return nil, err
}
return nil, s.agent.Unlock(req.Passphrase)
case agentSignRequest:
var req signRequestAgentMsg
if err := ssh.Unmarshal(data, &req); err != nil {
return nil, err
}
var wk wireKey
if err := ssh.Unmarshal(req.KeyBlob, &wk); err != nil {
return nil, err
}
k := &Key{
Format: wk.Format,
Blob: req.KeyBlob,
}
var sig *ssh.Signature
var err error
if extendedAgent, ok := s.agent.(ExtendedAgent); ok {
sig, err = extendedAgent.SignWithFlags(k, req.Data, SignatureFlags(req.Flags))
} else {
sig, err = s.agent.Sign(k, req.Data)
}
if err != nil {
return nil, err
}
return &signResponseAgentMsg{SigBlob: ssh.Marshal(sig)}, nil
case agentRequestIdentities:
keys, err := s.agent.List()
if err != nil {
return nil, err
}
rep := identitiesAnswerAgentMsg{
NumKeys: uint32(len(keys)),
}
for _, k := range keys {
rep.Keys = append(rep.Keys, marshalKey(k)...)
}
return rep, nil
case agentAddIDConstrained, agentAddIdentity:
return nil, s.insertIdentity(data)
case agentExtension:
// Return a stub object where the whole contents of the response gets marshaled.
var responseStub struct {
Rest []byte `ssh:"rest"`
}
if extendedAgent, ok := s.agent.(ExtendedAgent); !ok {
// If this agent doesn't implement extensions, [PROTOCOL.agent] section 4.7
// requires that we return a standard SSH_AGENT_FAILURE message.
responseStub.Rest = []byte{agentFailure}
} else {
var req extensionAgentMsg
if err := ssh.Unmarshal(data, &req); err != nil {
return nil, err
}
res, err := extendedAgent.Extension(req.ExtensionType, req.Contents)
if err != nil {
// If agent extensions are unsupported, return a standard SSH_AGENT_FAILURE
// message as required by [PROTOCOL.agent] section 4.7.
if err == ErrExtensionUnsupported {
responseStub.Rest = []byte{agentFailure}
} else {
// As the result of any other error processing an extension request,
// [PROTOCOL.agent] section 4.7 requires that we return a
// SSH_AGENT_EXTENSION_FAILURE code.
responseStub.Rest = []byte{agentExtensionFailure}
}
} else {
if len(res) == 0 {
return nil, nil
}
responseStub.Rest = res
}
}
return responseStub, nil
}
return nil, fmt.Errorf("unknown opcode %d", data[0])
}
func parseConstraints(constraints []byte) (lifetimeSecs uint32, confirmBeforeUse bool, extensions []ConstraintExtension, err error) {
for len(constraints) != 0 {
switch constraints[0] {
case agentConstrainLifetime:
lifetimeSecs = binary.BigEndian.Uint32(constraints[1:5])
constraints = constraints[5:]
case agentConstrainConfirm:
confirmBeforeUse = true
constraints = constraints[1:]
case agentConstrainExtension:
var msg constrainExtensionAgentMsg
if err = ssh.Unmarshal(constraints, &msg); err != nil {
return 0, false, nil, err
}
extensions = append(extensions, ConstraintExtension{
ExtensionName: msg.ExtensionName,
ExtensionDetails: msg.ExtensionDetails,
})
constraints = msg.Rest
default:
return 0, false, nil, fmt.Errorf("unknown constraint type: %d", constraints[0])
}
}
return
}
func setConstraints(key *AddedKey, constraintBytes []byte) error {
lifetimeSecs, confirmBeforeUse, constraintExtensions, err := parseConstraints(constraintBytes)
if err != nil {
return err
}
key.LifetimeSecs = lifetimeSecs
key.ConfirmBeforeUse = confirmBeforeUse
key.ConstraintExtensions = constraintExtensions
return nil
}
func parseRSAKey(req []byte) (*AddedKey, error) {
var k rsaKeyMsg
if err := ssh.Unmarshal(req, &k); err != nil {
return nil, err
}
if k.E.BitLen() > 30 {
return nil, errors.New("agent: RSA public exponent too large")
}
priv := &rsa.PrivateKey{
PublicKey: rsa.PublicKey{
E: int(k.E.Int64()),
N: k.N,
},
D: k.D,
Primes: []*big.Int{k.P, k.Q},
}
priv.Precompute()
addedKey := &AddedKey{PrivateKey: priv, Comment: k.Comments}
if err := setConstraints(addedKey, k.Constraints); err != nil {
return nil, err
}
return addedKey, nil
}
func parseEd25519Key(req []byte) (*AddedKey, error) {
var k ed25519KeyMsg
if err := ssh.Unmarshal(req, &k); err != nil {
return nil, err
}
priv := ed25519.PrivateKey(k.Priv)
addedKey := &AddedKey{PrivateKey: &priv, Comment: k.Comments}
if err := setConstraints(addedKey, k.Constraints); err != nil {
return nil, err
}
return addedKey, nil
}
func parseDSAKey(req []byte) (*AddedKey, error) {
var k dsaKeyMsg
if err := ssh.Unmarshal(req, &k); err != nil {
return nil, err
}
priv := &dsa.PrivateKey{
PublicKey: dsa.PublicKey{
Parameters: dsa.Parameters{
P: k.P,
Q: k.Q,
G: k.G,
},
Y: k.Y,
},
X: k.X,
}
addedKey := &AddedKey{PrivateKey: priv, Comment: k.Comments}
if err := setConstraints(addedKey, k.Constraints); err != nil {
return nil, err
}
return addedKey, nil
}
func unmarshalECDSA(curveName string, keyBytes []byte, privScalar *big.Int) (priv *ecdsa.PrivateKey, err error) {
priv = &ecdsa.PrivateKey{
D: privScalar,
}
switch curveName {
case "nistp256":
priv.Curve = elliptic.P256()
case "nistp384":
priv.Curve = elliptic.P384()
case "nistp521":
priv.Curve = elliptic.P521()
default:
return nil, fmt.Errorf("agent: unknown curve %q", curveName)
}
priv.X, priv.Y = elliptic.Unmarshal(priv.Curve, keyBytes)
if priv.X == nil || priv.Y == nil {
return nil, errors.New("agent: point not on curve")
}
return priv, nil
}
func parseEd25519Cert(req []byte) (*AddedKey, error) {
var k ed25519CertMsg
if err := ssh.Unmarshal(req, &k); err != nil {
return nil, err
}
pubKey, err := ssh.ParsePublicKey(k.CertBytes)
if err != nil {
return nil, err
}
priv := ed25519.PrivateKey(k.Priv)
cert, ok := pubKey.(*ssh.Certificate)
if !ok {
return nil, errors.New("agent: bad ED25519 certificate")
}
addedKey := &AddedKey{PrivateKey: &priv, Certificate: cert, Comment: k.Comments}
if err := setConstraints(addedKey, k.Constraints); err != nil {
return nil, err
}
return addedKey, nil
}
func parseECDSAKey(req []byte) (*AddedKey, error) {
var k ecdsaKeyMsg
if err := ssh.Unmarshal(req, &k); err != nil {
return nil, err
}
priv, err := unmarshalECDSA(k.Curve, k.KeyBytes, k.D)
if err != nil {
return nil, err
}
addedKey := &AddedKey{PrivateKey: priv, Comment: k.Comments}
if err := setConstraints(addedKey, k.Constraints); err != nil {
return nil, err
}
return addedKey, nil
}
func parseRSACert(req []byte) (*AddedKey, error) {
var k rsaCertMsg
if err := ssh.Unmarshal(req, &k); err != nil {
return nil, err
}
pubKey, err := ssh.ParsePublicKey(k.CertBytes)
if err != nil {
return nil, err
}
cert, ok := pubKey.(*ssh.Certificate)
if !ok {
return nil, errors.New("agent: bad RSA certificate")
}
// An RSA publickey as marshaled by rsaPublicKey.Marshal() in keys.go
var rsaPub struct {
Name string
E *big.Int
N *big.Int
}
if err := ssh.Unmarshal(cert.Key.Marshal(), &rsaPub); err != nil {
return nil, fmt.Errorf("agent: Unmarshal failed to parse public key: %v", err)
}
if rsaPub.E.BitLen() > 30 {
return nil, errors.New("agent: RSA public exponent too large")
}
priv := rsa.PrivateKey{
PublicKey: rsa.PublicKey{
E: int(rsaPub.E.Int64()),
N: rsaPub.N,
},
D: k.D,
Primes: []*big.Int{k.Q, k.P},
}
priv.Precompute()
addedKey := &AddedKey{PrivateKey: &priv, Certificate: cert, Comment: k.Comments}
if err := setConstraints(addedKey, k.Constraints); err != nil {
return nil, err
}
return addedKey, nil
}
func parseDSACert(req []byte) (*AddedKey, error) {
var k dsaCertMsg
if err := ssh.Unmarshal(req, &k); err != nil {
return nil, err
}
pubKey, err := ssh.ParsePublicKey(k.CertBytes)
if err != nil {
return nil, err
}
cert, ok := pubKey.(*ssh.Certificate)
if !ok {
return nil, errors.New("agent: bad DSA certificate")
}
// A DSA publickey as marshaled by dsaPublicKey.Marshal() in keys.go
var w struct {
Name string
P, Q, G, Y *big.Int
}
if err := ssh.Unmarshal(cert.Key.Marshal(), &w); err != nil {
return nil, fmt.Errorf("agent: Unmarshal failed to parse public key: %v", err)
}
priv := &dsa.PrivateKey{
PublicKey: dsa.PublicKey{
Parameters: dsa.Parameters{
P: w.P,
Q: w.Q,
G: w.G,
},
Y: w.Y,
},
X: k.X,
}
addedKey := &AddedKey{PrivateKey: priv, Certificate: cert, Comment: k.Comments}
if err := setConstraints(addedKey, k.Constraints); err != nil {
return nil, err
}
return addedKey, nil
}
func parseECDSACert(req []byte) (*AddedKey, error) {
var k ecdsaCertMsg
if err := ssh.Unmarshal(req, &k); err != nil {
return nil, err
}
pubKey, err := ssh.ParsePublicKey(k.CertBytes)
if err != nil {
return nil, err
}
cert, ok := pubKey.(*ssh.Certificate)
if !ok {
return nil, errors.New("agent: bad ECDSA certificate")
}
// An ECDSA publickey as marshaled by ecdsaPublicKey.Marshal() in keys.go
var ecdsaPub struct {
Name string
ID string
Key []byte
}
if err := ssh.Unmarshal(cert.Key.Marshal(), &ecdsaPub); err != nil {
return nil, err
}
priv, err := unmarshalECDSA(ecdsaPub.ID, ecdsaPub.Key, k.D)
if err != nil {
return nil, err
}
addedKey := &AddedKey{PrivateKey: priv, Certificate: cert, Comment: k.Comments}
if err := setConstraints(addedKey, k.Constraints); err != nil {
return nil, err
}
return addedKey, nil
}
func (s *server) insertIdentity(req []byte) error {
var record struct {
Type string `sshtype:"17|25"`
Rest []byte `ssh:"rest"`
}
if err := ssh.Unmarshal(req, &record); err != nil {
return err
}
var addedKey *AddedKey
var err error
switch record.Type {
case ssh.KeyAlgoRSA:
addedKey, err = parseRSAKey(req)
case ssh.KeyAlgoDSA:
addedKey, err = parseDSAKey(req)
case ssh.KeyAlgoECDSA256, ssh.KeyAlgoECDSA384, ssh.KeyAlgoECDSA521:
addedKey, err = parseECDSAKey(req)
case ssh.KeyAlgoED25519:
addedKey, err = parseEd25519Key(req)
case ssh.CertAlgoRSAv01:
addedKey, err = parseRSACert(req)
case ssh.CertAlgoDSAv01:
addedKey, err = parseDSACert(req)
case ssh.CertAlgoECDSA256v01, ssh.CertAlgoECDSA384v01, ssh.CertAlgoECDSA521v01:
addedKey, err = parseECDSACert(req)
case ssh.CertAlgoED25519v01:
addedKey, err = parseEd25519Cert(req)
default:
return fmt.Errorf("agent: not implemented: %q", record.Type)
}
if err != nil {
return err
}
return s.agent.Add(*addedKey)
}
// ServeAgent serves the agent protocol on the given connection. It
// returns when an I/O error occurs.
func ServeAgent(agent Agent, c io.ReadWriter) error {
s := &server{agent}
var length [4]byte
for {
if _, err := io.ReadFull(c, length[:]); err != nil {
return err
}
l := binary.BigEndian.Uint32(length[:])
if l == 0 {
return fmt.Errorf("agent: request size is 0")
}
if l > maxAgentResponseBytes {
// We also cap requests.
return fmt.Errorf("agent: request too large: %d", l)
}
req := make([]byte, l)
if _, err := io.ReadFull(c, req); err != nil {
return err
}
repData := s.processRequestBytes(req)
if len(repData) > maxAgentResponseBytes {
return fmt.Errorf("agent: reply too large: %d bytes", len(repData))
}
binary.BigEndian.PutUint32(length[:], uint32(len(repData)))
if _, err := c.Write(length[:]); err != nil {
return err
}
if _, err := c.Write(repData); err != nil {
return err
}
}
}

1
vendor/modules.txt vendored
View File

@ -575,6 +575,7 @@ golang.org/x/crypto/openpgp/s2k
golang.org/x/crypto/pbkdf2
golang.org/x/crypto/poly1305
golang.org/x/crypto/ssh
golang.org/x/crypto/ssh/agent
golang.org/x/crypto/ssh/internal/bcrypt_pbkdf
golang.org/x/crypto/ssh/terminal
# golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7