distribution/registry/client/auth/session.go
Sebastiaan van Stijn c8ba5d7081
registry/client: combine SuccessStatus and HandleErrorResponse
The SuccessStatus acted on the response's status code, and was used to return
early, before checking the same status code with HandleErrorResponse.

This patch combines both functions into a HandleHTTPResponseError, which
returns an error for "non-success" status-codes, which simplifies handling
of responses, and makes some logic slightly more idiomatic.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2023-09-08 14:40:41 +02:00

537 lines
14 KiB
Go

package auth
import (
"context"
"encoding/json"
"errors"
"fmt"
"net/http"
"net/url"
"strings"
"sync"
"time"
"github.com/distribution/distribution/v3/registry/client"
"github.com/distribution/distribution/v3/registry/client/auth/challenge"
"github.com/distribution/distribution/v3/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(req.Context(), params, additionalScopes...)
if err != nil {
return err
}
req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
return nil
}
func (th *tokenHandler) getToken(ctx context.Context, 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(ctx, 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(ctx context.Context, 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")
}
req, err := http.NewRequestWithContext(ctx, http.MethodPost, realm.String(), strings.NewReader(form.Encode()))
if err != nil {
return "", time.Time{}, err
}
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
resp, err := th.client().Do(req)
if err != nil {
return "", time.Time{}, err
}
defer resp.Body.Close()
if err := client.HandleHTTPResponseError(resp); err != nil {
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.AccessToken == "" {
return "", time.Time{}, ErrNoToken
}
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(ctx context.Context, realm *url.URL, service string, scopes []string) (token string, expiration time.Time, err error) {
req, err := http.NewRequestWithContext(ctx, http.MethodGet, 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 err := client.HandleHTTPResponseError(resp); err != nil {
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(ctx context.Context, 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(ctx, realmURL, refreshToken, service, scopes)
}
return th.fetchTokenWithBasicAuth(ctx, 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
}