distribution/registry/client/auth/session.go

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package auth
import (
"encoding/json"
"errors"
"fmt"
"net/http"
"net/url"
"strings"
"sync"
"time"
"github.com/docker/distribution/registry/client"
"github.com/docker/distribution/registry/client/auth/challenge"
"github.com/docker/distribution/registry/client/transport"
)
var (
// ErrNoBasicAuthCredentials is returned if a request can't be authorized with
// basic auth due to lack of credentials.
ErrNoBasicAuthCredentials = errors.New("no basic auth credentials")
// ErrNoToken is returned if a request is successful but the body does not
// contain an authorization token.
ErrNoToken = errors.New("authorization server did not include a token in the response")
)
const defaultClientID = "registry-client"
// AuthenticationHandler is an interface for authorizing a request from
// params from a "WWW-Authenicate" header for a single scheme.
type AuthenticationHandler interface {
// Scheme returns the scheme as expected from the "WWW-Authenicate" header.
Scheme() string
// AuthorizeRequest adds the authorization header to a request (if needed)
// using the parameters from "WWW-Authenticate" method. The parameters
// values depend on the scheme.
AuthorizeRequest(req *http.Request, params map[string]string) error
}
// CredentialStore is an interface for getting credentials for
// a given URL
type CredentialStore interface {
// Basic returns basic auth for the given URL
Basic(*url.URL) (string, string)
// RefreshToken returns a refresh token for the
// given URL and service
RefreshToken(*url.URL, string) string
// SetRefreshToken sets the refresh token if none
// is provided for the given url and service
SetRefreshToken(realm *url.URL, service, token string)
}
// NewAuthorizer creates an authorizer which can handle multiple authentication
// schemes. The handlers are tried in order, the higher priority authentication
// methods should be first. The challengeMap holds a list of challenges for
// a given root API endpoint (for example "https://registry-1.docker.io/v2/").
func NewAuthorizer(manager challenge.Manager, handlers ...AuthenticationHandler) transport.RequestModifier {
return &endpointAuthorizer{
challenges: manager,
handlers: handlers,
}
}
type endpointAuthorizer struct {
challenges challenge.Manager
handlers []AuthenticationHandler
}
func (ea *endpointAuthorizer) ModifyRequest(req *http.Request) error {
pingPath := req.URL.Path
if v2Root := strings.Index(req.URL.Path, "/v2/"); v2Root != -1 {
pingPath = pingPath[:v2Root+4]
} else if v1Root := strings.Index(req.URL.Path, "/v1/"); v1Root != -1 {
pingPath = pingPath[:v1Root] + "/v2/"
} else {
return nil
}
ping := url.URL{
Host: req.URL.Host,
Scheme: req.URL.Scheme,
Path: pingPath,
}
challenges, err := ea.challenges.GetChallenges(ping)
if err != nil {
return err
}
if len(challenges) > 0 {
for _, handler := range ea.handlers {
for _, c := range challenges {
if c.Scheme != handler.Scheme() {
continue
}
if err := handler.AuthorizeRequest(req, c.Parameters); err != nil {
return err
}
}
}
}
return nil
}
// This is the minimum duration a token can last (in seconds).
// A token must not live less than 60 seconds because older versions
// of the Docker client didn't read their expiration from the token
// response and assumed 60 seconds. So to remain compatible with
// those implementations, a token must live at least this long.
const minimumTokenLifetimeSeconds = 60
// Private interface for time used by this package to enable tests to provide their own implementation.
type clock interface {
Now() time.Time
}
type tokenHandler struct {
creds CredentialStore
transport http.RoundTripper
clock clock
offlineAccess bool
forceOAuth bool
clientID string
scopes []Scope
tokenLock sync.Mutex
tokenCache string
tokenExpiration time.Time
logger Logger
}
// Scope is a type which is serializable to a string
// using the allow scope grammar.
type Scope interface {
String() string
}
// RepositoryScope represents a token scope for access
// to a repository.
type RepositoryScope struct {
Repository string
Class string
Actions []string
}
// String returns the string representation of the repository
// using the scope grammar
func (rs RepositoryScope) String() string {
repoType := "repository"
// Keep existing format for image class to maintain backwards compatibility
// with authorization servers which do not support the expanded grammar.
if rs.Class != "" && rs.Class != "image" {
repoType = fmt.Sprintf("%s(%s)", repoType, rs.Class)
}
return fmt.Sprintf("%s:%s:%s", repoType, rs.Repository, strings.Join(rs.Actions, ","))
}
// RegistryScope represents a token scope for access
// to resources in the registry.
type RegistryScope struct {
Name string
Actions []string
}
// String returns the string representation of the user
// using the scope grammar
func (rs RegistryScope) String() string {
return fmt.Sprintf("registry:%s:%s", rs.Name, strings.Join(rs.Actions, ","))
}
// Logger defines the injectable logging interface, used on TokenHandlers.
type Logger interface {
Debugf(format string, args ...interface{})
}
func logDebugf(logger Logger, format string, args ...interface{}) {
if logger == nil {
return
}
logger.Debugf(format, args...)
}
// TokenHandlerOptions is used to configure a new token handler
type TokenHandlerOptions struct {
Transport http.RoundTripper
Credentials CredentialStore
OfflineAccess bool
ForceOAuth bool
ClientID string
Scopes []Scope
Logger Logger
}
// An implementation of clock for providing real time data.
type realClock struct{}
// Now implements clock
func (realClock) Now() time.Time { return time.Now() }
// NewTokenHandler creates a new AuthenicationHandler which supports
// fetching tokens from a remote token server.
func NewTokenHandler(transport http.RoundTripper, creds CredentialStore, scope string, actions ...string) AuthenticationHandler {
// Create options...
return NewTokenHandlerWithOptions(TokenHandlerOptions{
Transport: transport,
Credentials: creds,
Scopes: []Scope{
RepositoryScope{
Repository: scope,
Actions: actions,
},
},
})
}
// NewTokenHandlerWithOptions creates a new token handler using the provided
// options structure.
func NewTokenHandlerWithOptions(options TokenHandlerOptions) AuthenticationHandler {
handler := &tokenHandler{
transport: options.Transport,
creds: options.Credentials,
offlineAccess: options.OfflineAccess,
forceOAuth: options.ForceOAuth,
clientID: options.ClientID,
scopes: options.Scopes,
clock: realClock{},
logger: options.Logger,
}
return handler
}
func (th *tokenHandler) client() *http.Client {
return &http.Client{
Transport: th.transport,
Timeout: 15 * time.Second,
}
}
func (th *tokenHandler) Scheme() string {
return "bearer"
}
func (th *tokenHandler) AuthorizeRequest(req *http.Request, params map[string]string) error {
var additionalScopes []string
if fromParam := req.URL.Query().Get("from"); fromParam != "" {
additionalScopes = append(additionalScopes, RepositoryScope{
Repository: fromParam,
Actions: []string{"pull"},
}.String())
}
token, err := th.getToken(params, additionalScopes...)
if err != nil {
return err
}
req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
return nil
}
func (th *tokenHandler) getToken(params map[string]string, additionalScopes ...string) (string, error) {
th.tokenLock.Lock()
defer th.tokenLock.Unlock()
scopes := make([]string, 0, len(th.scopes)+len(additionalScopes))
for _, scope := range th.scopes {
scopes = append(scopes, scope.String())
}
var addedScopes bool
for _, scope := range additionalScopes {
if hasScope(scopes, scope) {
continue
}
scopes = append(scopes, scope)
addedScopes = true
}
now := th.clock.Now()
if now.After(th.tokenExpiration) || addedScopes {
token, expiration, err := th.fetchToken(params, scopes)
if err != nil {
return "", err
}
// do not update cache for added scope tokens
if !addedScopes {
th.tokenCache = token
th.tokenExpiration = expiration
}
return token, nil
}
return th.tokenCache, nil
}
func hasScope(scopes []string, scope string) bool {
for _, s := range scopes {
if s == scope {
return true
}
}
return false
}
type postTokenResponse struct {
AccessToken string `json:"access_token"`
RefreshToken string `json:"refresh_token"`
ExpiresIn int `json:"expires_in"`
IssuedAt time.Time `json:"issued_at"`
Scope string `json:"scope"`
}
func (th *tokenHandler) fetchTokenWithOAuth(realm *url.URL, refreshToken, service string, scopes []string) (token string, expiration time.Time, err error) {
form := url.Values{}
form.Set("scope", strings.Join(scopes, " "))
form.Set("service", service)
clientID := th.clientID
if clientID == "" {
// Use default client, this is a required field
clientID = defaultClientID
}
form.Set("client_id", clientID)
if refreshToken != "" {
form.Set("grant_type", "refresh_token")
form.Set("refresh_token", refreshToken)
} else if th.creds != nil {
form.Set("grant_type", "password")
username, password := th.creds.Basic(realm)
form.Set("username", username)
form.Set("password", password)
// attempt to get a refresh token
form.Set("access_type", "offline")
} else {
// refuse to do oauth without a grant type
return "", time.Time{}, fmt.Errorf("no supported grant type")
}
resp, err := th.client().PostForm(realm.String(), form)
if err != nil {
return "", time.Time{}, err
}
defer resp.Body.Close()
if !client.SuccessStatus(resp.StatusCode) {
err := client.HandleErrorResponse(resp)
return "", time.Time{}, err
}
decoder := json.NewDecoder(resp.Body)
var tr postTokenResponse
if err = decoder.Decode(&tr); err != nil {
return "", time.Time{}, fmt.Errorf("unable to decode token response: %s", err)
}
if tr.RefreshToken != "" && tr.RefreshToken != refreshToken {
th.creds.SetRefreshToken(realm, service, tr.RefreshToken)
}
if tr.ExpiresIn < minimumTokenLifetimeSeconds {
// The default/minimum lifetime.
tr.ExpiresIn = minimumTokenLifetimeSeconds
logDebugf(th.logger, "Increasing token expiration to: %d seconds", tr.ExpiresIn)
}
if tr.IssuedAt.IsZero() {
// issued_at is optional in the token response.
tr.IssuedAt = th.clock.Now().UTC()
}
return tr.AccessToken, tr.IssuedAt.Add(time.Duration(tr.ExpiresIn) * time.Second), nil
}
type getTokenResponse struct {
Token string `json:"token"`
AccessToken string `json:"access_token"`
ExpiresIn int `json:"expires_in"`
IssuedAt time.Time `json:"issued_at"`
RefreshToken string `json:"refresh_token"`
}
func (th *tokenHandler) fetchTokenWithBasicAuth(realm *url.URL, service string, scopes []string) (token string, expiration time.Time, err error) {
req, err := http.NewRequest("GET", realm.String(), nil)
if err != nil {
return "", time.Time{}, err
}
reqParams := req.URL.Query()
if service != "" {
reqParams.Add("service", service)
}
for _, scope := range scopes {
reqParams.Add("scope", scope)
}
if th.offlineAccess {
reqParams.Add("offline_token", "true")
clientID := th.clientID
if clientID == "" {
clientID = defaultClientID
}
reqParams.Add("client_id", clientID)
}
if th.creds != nil {
username, password := th.creds.Basic(realm)
if username != "" && password != "" {
reqParams.Add("account", username)
req.SetBasicAuth(username, password)
}
}
req.URL.RawQuery = reqParams.Encode()
resp, err := th.client().Do(req)
if err != nil {
return "", time.Time{}, err
}
defer resp.Body.Close()
if !client.SuccessStatus(resp.StatusCode) {
err := client.HandleErrorResponse(resp)
return "", time.Time{}, err
}
decoder := json.NewDecoder(resp.Body)
var tr getTokenResponse
if err = decoder.Decode(&tr); err != nil {
return "", time.Time{}, fmt.Errorf("unable to decode token response: %s", err)
}
if tr.RefreshToken != "" && th.creds != nil {
th.creds.SetRefreshToken(realm, service, tr.RefreshToken)
}
// `access_token` is equivalent to `token` and if both are specified
// the choice is undefined. Canonicalize `access_token` by sticking
// things in `token`.
if tr.AccessToken != "" {
tr.Token = tr.AccessToken
}
if tr.Token == "" {
return "", time.Time{}, ErrNoToken
}
if tr.ExpiresIn < minimumTokenLifetimeSeconds {
// The default/minimum lifetime.
tr.ExpiresIn = minimumTokenLifetimeSeconds
logDebugf(th.logger, "Increasing token expiration to: %d seconds", tr.ExpiresIn)
}
if tr.IssuedAt.IsZero() {
// issued_at is optional in the token response.
tr.IssuedAt = th.clock.Now().UTC()
}
return tr.Token, tr.IssuedAt.Add(time.Duration(tr.ExpiresIn) * time.Second), nil
}
func (th *tokenHandler) fetchToken(params map[string]string, scopes []string) (token string, expiration time.Time, err error) {
realm, ok := params["realm"]
if !ok {
return "", time.Time{}, errors.New("no realm specified for token auth challenge")
}
// TODO(dmcgowan): Handle empty scheme and relative realm
realmURL, err := url.Parse(realm)
if err != nil {
return "", time.Time{}, fmt.Errorf("invalid token auth challenge realm: %s", err)
}
service := params["service"]
var refreshToken string
if th.creds != nil {
refreshToken = th.creds.RefreshToken(realmURL, service)
}
if refreshToken != "" || th.forceOAuth {
return th.fetchTokenWithOAuth(realmURL, refreshToken, service, scopes)
}
return th.fetchTokenWithBasicAuth(realmURL, service, scopes)
}
type basicHandler struct {
creds CredentialStore
}
// NewBasicHandler creaters a new authentiation handler which adds
// basic authentication credentials to a request.
func NewBasicHandler(creds CredentialStore) AuthenticationHandler {
return &basicHandler{
creds: creds,
}
}
func (*basicHandler) Scheme() string {
return "basic"
}
func (bh *basicHandler) AuthorizeRequest(req *http.Request, params map[string]string) error {
if bh.creds != nil {
username, password := bh.creds.Basic(req.URL)
if username != "" && password != "" {
req.SetBasicAuth(username, password)
return nil
}
}
return ErrNoBasicAuthCredentials
}