Add challenge manager interface

Challenger manager interface is used to handle getting authorization challenges from an endpoint as well as extracting challenges from responses.

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)

docs/client/auth/authchallenge.go

@@ -1,7 +1,9 @@
 package auth
 
 import (
+	"fmt"
 	"net/http"
+	"net/url"
 	"strings"
 )
 
@@ -15,6 +17,57 @@ type Challenge struct {
 	Parameters map[string]string
 }
 
+// ChallengeManager manages the challenges for endpoints.
+// The challenges are pulled out of HTTP responses. Only
+// responses which expect challenges should be added to
+// the manager, since a non-unauthorized request will be
+// viewed as not requiring challenges.
+type ChallengeManager interface {
+	// GetChallenges returns the challenges for the given
+	// endpoint URL.
+	GetChallenges(endpoint string) ([]Challenge, error)
+
+	// AddResponse adds the response to the challenge
+	// manager. The challenges will be parsed out of
+	// the WWW-Authenicate headers and added to the
+	// URL which was produced the response. If the
+	// response was authorized, any challenges for the
+	// endpoint will be cleared.
+	AddResponse(resp *http.Response) error
+}
+
+// NewSimpleChallengeManager returns an instance of
+// ChallengeManger which only maps endpoints to challenges
+// based on the responses which have been added the
+// manager. The simple manager will make no attempt to
+// perform requests on the endpoints or cache the responses
+// to a backend.
+func NewSimpleChallengeManager() ChallengeManager {
+	return simpleChallengeManager{}
+}
+
+type simpleChallengeManager map[string][]Challenge
+
+func (m simpleChallengeManager) GetChallenges(endpoint string) ([]Challenge, error) {
+	challenges := m[endpoint]
+	return challenges, nil
+}
+
+func (m simpleChallengeManager) AddResponse(resp *http.Response) error {
+	challenges := ResponseChallenges(resp)
+	if resp.Request == nil {
+		return fmt.Errorf("missing request reference")
+	}
+	urlCopy := url.URL{
+		Path:   resp.Request.URL.Path,
+		Host:   resp.Request.URL.Host,
+		Scheme: resp.Request.URL.Scheme,
+	}
+	m[urlCopy.String()] = challenges
+
+	return nil
+}
+
 // Octet types from RFC 2616.
 type octetType byte
 

docs/client/auth/session.go

@@ -36,15 +36,15 @@ type CredentialStore interface {
 // 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(challengeMap map[string][]Challenge, handlers ...AuthenticationHandler) transport.RequestModifier {
+func NewAuthorizer(manager ChallengeManager, handlers ...AuthenticationHandler) transport.RequestModifier {
 	return &endpointAuthorizer{
-		challenges: challengeMap,
+		challenges: manager,
 		handlers:   handlers,
 	}
 }
 
 type endpointAuthorizer struct {
-	challenges map[string][]Challenge
+	challenges ChallengeManager
 	handlers   []AuthenticationHandler
 	transport  http.RoundTripper
 }
@@ -63,18 +63,20 @@ func (ea *endpointAuthorizer) ModifyRequest(req *http.Request) error {
 
 	pingEndpoint := ping.String()
 
-	challenges, ok := ea.challenges[pingEndpoint]
+	challenges, err := ea.challenges.GetChallenges(pingEndpoint)
-	if !ok {
+	if err != nil {
-		return nil
+		return err
 	}
 
-	for _, handler := range ea.handlers {
+	if len(challenges) > 0 {
-		for _, challenge := range challenges {
+		for _, handler := range ea.handlers {
-			if challenge.Scheme != handler.Scheme() {
+			for _, challenge := range challenges {
-				continue
+				if challenge.Scheme != handler.Scheme() {
-			}
+					continue
-			if err := handler.AuthorizeRequest(req, challenge.Parameters); err != nil {
+				}
-				return err
+				if err := handler.AuthorizeRequest(req, challenge.Parameters); err != nil {
+					return err
+				}
 			}
 		}
 	}

docs/client/auth/session_test.go

@@ -56,14 +56,18 @@ func testServerWithAuth(rrm testutil.RequestResponseMap, authenticate string, au
 
 // ping pings the provided endpoint to determine its required authorization challenges.
 // If a version header is provided, the versions will be returned.
-func ping(endpoint, versionHeader string) ([]Challenge, []APIVersion, error) {
+func ping(manager ChallengeManager, endpoint, versionHeader string) ([]APIVersion, error) {
 	resp, err := http.Get(endpoint)
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	defer resp.Body.Close()
 
-	return ResponseChallenges(resp), APIVersions(resp, versionHeader), err
+	if err := manager.AddResponse(resp); err != nil {
+		return nil, err
+	}
+
+	return APIVersions(resp, versionHeader), err
 }
 
 type testCredentialStore struct {
@@ -125,7 +129,8 @@ func TestEndpointAuthorizeToken(t *testing.T) {
 	e, c := testServerWithAuth(m, authenicate, validCheck)
 	defer c()
 
-	challenges1, versions, err := ping(e+"/v2/", "x-api-version")
+	challengeManager1 := NewSimpleChallengeManager()
+	versions, err := ping(challengeManager1, e+"/v2/", "x-api-version")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -135,10 +140,7 @@ func TestEndpointAuthorizeToken(t *testing.T) {
 	if check := (APIVersion{Type: "registry", Version: "2.0"}); versions[0] != check {
 		t.Fatalf("Unexpected api version: %#v, expected %#v", versions[0], check)
 	}
-	challengeMap1 := map[string][]Challenge{
+	transport1 := transport.NewTransport(nil, NewAuthorizer(challengeManager1, NewTokenHandler(nil, nil, repo1, "pull", "push")))
-		e + "/v2/": challenges1,
-	}
-	transport1 := transport.NewTransport(nil, NewAuthorizer(challengeMap1, NewTokenHandler(nil, nil, repo1, "pull", "push")))
 	client := &http.Client{Transport: transport1}
 
 	req, _ := http.NewRequest("GET", e+"/v2/hello", nil)
@@ -157,7 +159,8 @@ func TestEndpointAuthorizeToken(t *testing.T) {
 	e2, c2 := testServerWithAuth(m, authenicate, badCheck)
 	defer c2()
 
-	challenges2, versions, err := ping(e+"/v2/", "x-multi-api-version")
+	challengeManager2 := NewSimpleChallengeManager()
+	versions, err = ping(challengeManager2, e+"/v2/", "x-multi-api-version")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -173,10 +176,7 @@ func TestEndpointAuthorizeToken(t *testing.T) {
 	if check := (APIVersion{Type: "trust", Version: "1.0"}); versions[2] != check {
 		t.Fatalf("Unexpected api version: %#v, expected %#v", versions[2], check)
 	}
-	challengeMap2 := map[string][]Challenge{
+	transport2 := transport.NewTransport(nil, NewAuthorizer(challengeManager2, NewTokenHandler(nil, nil, repo2, "pull", "push")))
-		e + "/v2/": challenges2,
-	}
-	transport2 := transport.NewTransport(nil, NewAuthorizer(challengeMap2, NewTokenHandler(nil, nil, repo2, "pull", "push")))
 	client2 := &http.Client{Transport: transport2}
 
 	req, _ = http.NewRequest("GET", e2+"/v2/hello", nil)
@@ -246,14 +246,12 @@ func TestEndpointAuthorizeTokenBasic(t *testing.T) {
 		password: password,
 	}
 
-	challenges, _, err := ping(e+"/v2/", "")
+	challengeManager := NewSimpleChallengeManager()
+	_, err := ping(challengeManager, e+"/v2/", "")
 	if err != nil {
 		t.Fatal(err)
 	}
-	challengeMap := map[string][]Challenge{
+	transport1 := transport.NewTransport(nil, NewAuthorizer(challengeManager, NewTokenHandler(nil, creds, repo, "pull", "push"), NewBasicHandler(creds)))
-		e + "/v2/": challenges,
-	}
-	transport1 := transport.NewTransport(nil, NewAuthorizer(challengeMap, NewTokenHandler(nil, creds, repo, "pull", "push"), NewBasicHandler(creds)))
 	client := &http.Client{Transport: transport1}
 
 	req, _ := http.NewRequest("GET", e+"/v2/hello", nil)
@@ -293,14 +291,12 @@ func TestEndpointAuthorizeBasic(t *testing.T) {
 		password: password,
 	}
 
-	challenges, _, err := ping(e+"/v2/", "")
+	challengeManager := NewSimpleChallengeManager()
+	_, err := ping(challengeManager, e+"/v2/", "")
 	if err != nil {
 		t.Fatal(err)
 	}
-	challengeMap := map[string][]Challenge{
+	transport1 := transport.NewTransport(nil, NewAuthorizer(challengeManager, NewBasicHandler(creds)))
-		e + "/v2/": challenges,
-	}
-	transport1 := transport.NewTransport(nil, NewAuthorizer(challengeMap, NewBasicHandler(creds)))
 	client := &http.Client{Transport: transport1}
 
 	req, _ := http.NewRequest("GET", e+"/v2/hello", nil)