Remove dead code in registry package

The only uses of RequestAuthorization and its associated functions were
removed in 19515a7ad859b28c474d81e756ac245afcd968e3 ("Update graph to
use vendored distribution client for the v2 codepath")

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>

registry/auth.go

@@ -6,100 +6,11 @@ import (
 	"io/ioutil"
 	"net/http"
 	"strings"
-	"sync"
-	"time"
 
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/cliconfig"
 )
 
-type RequestAuthorization struct {
-	authConfig       *cliconfig.AuthConfig
-	registryEndpoint *Endpoint
-	resource         string
-	scope            string
-	actions          []string
-
-	tokenLock       sync.Mutex
-	tokenCache      string
-	tokenExpiration time.Time
-}
-
-func NewRequestAuthorization(authConfig *cliconfig.AuthConfig, registryEndpoint *Endpoint, resource, scope string, actions []string) *RequestAuthorization {
-	return &RequestAuthorization{
-		authConfig:       authConfig,
-		registryEndpoint: registryEndpoint,
-		resource:         resource,
-		scope:            scope,
-		actions:          actions,
-	}
-}
-
-func (auth *RequestAuthorization) getToken() (string, error) {
-	auth.tokenLock.Lock()
-	defer auth.tokenLock.Unlock()
-	now := time.Now()
-	if now.Before(auth.tokenExpiration) {
-		logrus.Debugf("Using cached token for %s", auth.authConfig.Username)
-		return auth.tokenCache, nil
-	}
-
-	for _, challenge := range auth.registryEndpoint.AuthChallenges {
-		switch strings.ToLower(challenge.Scheme) {
-		case "basic":
-			// no token necessary
-		case "bearer":
-			logrus.Debugf("Getting bearer token with %s for %s", challenge.Parameters, auth.authConfig.Username)
-			params := map[string]string{}
-			for k, v := range challenge.Parameters {
-				params[k] = v
-			}
-			params["scope"] = fmt.Sprintf("%s:%s:%s", auth.resource, auth.scope, strings.Join(auth.actions, ","))
-			token, err := getToken(auth.authConfig.Username, auth.authConfig.Password, params, auth.registryEndpoint)
-			if err != nil {
-				return "", err
-			}
-			auth.tokenCache = token
-			auth.tokenExpiration = now.Add(time.Minute)
-
-			return token, nil
-		default:
-			logrus.Infof("Unsupported auth scheme: %q", challenge.Scheme)
-		}
-	}
-
-	// Do not expire cache since there are no challenges which use a token
-	auth.tokenExpiration = time.Now().Add(time.Hour * 24)
-
-	return "", nil
-}
-
-// Checks that requests to the v2 registry can be authorized.
-func (auth *RequestAuthorization) CanAuthorizeV2() bool {
-	if len(auth.registryEndpoint.AuthChallenges) == 0 {
-		return true
-	}
-	scope := fmt.Sprintf("%s:%s:%s", auth.resource, auth.scope, strings.Join(auth.actions, ","))
-	if _, err := loginV2(auth.authConfig, auth.registryEndpoint, scope); err != nil {
-		logrus.Debugf("Cannot authorize against V2 endpoint: %s", auth.registryEndpoint)
-		return false
-	}
-	return true
-}
-
-func (auth *RequestAuthorization) Authorize(req *http.Request) error {
-	token, err := auth.getToken()
-	if err != nil {
-		return err
-	}
-	if token != "" {
-		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
-	} else if auth.authConfig.Username != "" && auth.authConfig.Password != "" {
-		req.SetBasicAuth(auth.authConfig.Username, auth.authConfig.Password)
-	}
-	return nil
-}
-
 // Login tries to register/login to the registry server.
 func Login(authConfig *cliconfig.AuthConfig, registryEndpoint *Endpoint) (string, error) {
 	// Separates the v2 registry login logic from the v1 logic.