[SEC] Ensure propagation of API scopes for Conan and Container authentication

Gusted · forgejo-backport-action · commit ce10ec28786c · 2024-08-28T08:44:58.000Z
- The Conan and Container packages use a different type of authentication. It first authenticates via the regular way (api tokens or user:password, handled via `auth.Basic`) and then generates a JWT token that is used by the package software (such as Docker) to do the action they wanted to do. This JWT token didn't properly propagate the API scopes that the token was generated for, and thus could lead to a 'scope escalation' within the Conan and Container packages, read access to write access. - Store the API scope in the JWT token, so it can be propagated on subsequent calls that uses that JWT token. - Integration test added. - Resolves go-gitea#5128 (cherry picked from commit 5a871f6)
diff --git a/release-notes/5149.md b/release-notes/5149.md
@@ -0,0 +1 @@
+The scope of application tokens is not verified when writing containers or Conan packages. This is of no consequence when the user associated with the application token does not have write access to packages. If the user has write access to packages, such a token can be used to write containers and Conan packages.
diff --git a/routers/api/packages/conan/auth.go b/routers/api/packages/conan/auth.go
@@ -22,7 +22,7 @@ func (a *Auth) Name() string {
 
 // Verify extracts the user from the Bearer token
 func (a *Auth) Verify(req *http.Request, w http.ResponseWriter, store auth.DataStore, sess auth.SessionStore) (*user_model.User, error) {
-	uid, err := packages.ParseAuthorizationToken(req)
+	uid, scope, err := packages.ParseAuthorizationToken(req)
 	if err != nil {
 		log.Trace("ParseAuthorizationToken: %v", err)
 		return nil, err
@@ -32,6 +32,12 @@ func (a *Auth) Verify(req *http.Request, w http.ResponseWriter, store auth.DataS
 		return nil, nil
 	}
 
+	// Propagate scope of the authorization token.
+	if scope != "" {
+		store.GetData()["IsApiToken"] = true
+		store.GetData()["ApiTokenScope"] = scope
+	}
+
 	u, err := user_model.GetUserByID(req.Context(), uid)
 	if err != nil {
 		log.Error("GetUserByID:  %v", err)
diff --git a/routers/api/packages/conan/conan.go b/routers/api/packages/conan/conan.go
@@ -11,6 +11,7 @@ import (
 	"strings"
 	"time"
 
+	auth_model "code.gitea.io/gitea/models/auth"
 	"code.gitea.io/gitea/models/db"
 	packages_model "code.gitea.io/gitea/models/packages"
 	conan_model "code.gitea.io/gitea/models/packages/conan"
@@ -117,7 +118,10 @@ func Authenticate(ctx *context.Context) {
 		return
 	}
 
-	token, err := packages_service.CreateAuthorizationToken(ctx.Doer)
+	// If there's an API scope, ensure it propagates.
+	scope, _ := ctx.Data.GetData()["ApiTokenScope"].(auth_model.AccessTokenScope)
+
+	token, err := packages_service.CreateAuthorizationToken(ctx.Doer, scope)
 	if err != nil {
 		apiError(ctx, http.StatusInternalServerError, err)
 		return
diff --git a/routers/api/packages/container/auth.go b/routers/api/packages/container/auth.go
@@ -23,7 +23,7 @@ func (a *Auth) Name() string {
 // Verify extracts the user from the Bearer token
 // If it's an anonymous session a ghost user is returned
 func (a *Auth) Verify(req *http.Request, w http.ResponseWriter, store auth.DataStore, sess auth.SessionStore) (*user_model.User, error) {
-	uid, err := packages.ParseAuthorizationToken(req)
+	uid, scope, err := packages.ParseAuthorizationToken(req)
 	if err != nil {
 		log.Trace("ParseAuthorizationToken: %v", err)
 		return nil, err
@@ -33,6 +33,12 @@ func (a *Auth) Verify(req *http.Request, w http.ResponseWriter, store auth.DataS
 		return nil, nil
 	}
 
+	// Propagate scope of the authorization token.
+	if scope != "" {
+		store.GetData()["IsApiToken"] = true
+		store.GetData()["ApiTokenScope"] = scope
+	}
+
 	u, err := user_model.GetPossibleUserByID(req.Context(), uid)
 	if err != nil {
 		log.Error("GetPossibleUserByID:  %v", err)
diff --git a/routers/api/packages/container/container.go b/routers/api/packages/container/container.go
@@ -14,6 +14,7 @@ import (
 	"strconv"
 	"strings"
 
+	auth_model "code.gitea.io/gitea/models/auth"
 	packages_model "code.gitea.io/gitea/models/packages"
 	container_model "code.gitea.io/gitea/models/packages/container"
 	user_model "code.gitea.io/gitea/models/user"
@@ -154,7 +155,10 @@ func Authenticate(ctx *context.Context) {
 		u = user_model.NewGhostUser()
 	}
 
-	token, err := packages_service.CreateAuthorizationToken(u)
+	// If there's an API scope, ensure it propagates.
+	scope, _ := ctx.Data["ApiTokenScope"].(auth_model.AccessTokenScope)
+
+	token, err := packages_service.CreateAuthorizationToken(u, scope)
 	if err != nil {
 		apiError(ctx, http.StatusInternalServerError, err)
 		return
diff --git a/services/packages/auth.go b/services/packages/auth.go
@@ -9,6 +9,7 @@ import (
 	"strings"
 	"time"
 
+	auth_model "code.gitea.io/gitea/models/auth"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -19,9 +20,10 @@ import (
 type packageClaims struct {
 	jwt.RegisteredClaims
 	UserID int64
+	Scope  auth_model.AccessTokenScope
 }
 
-func CreateAuthorizationToken(u *user_model.User) (string, error) {
+func CreateAuthorizationToken(u *user_model.User, scope auth_model.AccessTokenScope) (string, error) {
 	now := time.Now()
 
 	claims := packageClaims{
@@ -30,6 +32,7 @@ func CreateAuthorizationToken(u *user_model.User) (string, error) {
 			NotBefore: jwt.NewNumericDate(now),
 		},
 		UserID: u.ID,
+		Scope:  scope,
 	}
 	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
 
@@ -41,16 +44,16 @@ func CreateAuthorizationToken(u *user_model.User) (string, error) {
 	return tokenString, nil
 }
 
-func ParseAuthorizationToken(req *http.Request) (int64, error) {
+func ParseAuthorizationToken(req *http.Request) (int64, auth_model.AccessTokenScope, error) {
 	h := req.Header.Get("Authorization")
 	if h == "" {
-		return 0, nil
+		return 0, "", nil
 	}
 
 	parts := strings.SplitN(h, " ", 2)
 	if len(parts) != 2 {
 		log.Error("split token failed: %s", h)
-		return 0, fmt.Errorf("split token failed")
+		return 0, "", fmt.Errorf("split token failed")
 	}
 
 	token, err := jwt.ParseWithClaims(parts[1], &packageClaims{}, func(t *jwt.Token) (any, error) {
@@ -60,13 +63,13 @@ func ParseAuthorizationToken(req *http.Request) (int64, error) {
 		return setting.GetGeneralTokenSigningSecret(), nil
 	})
 	if err != nil {
-		return 0, err
+		return 0, "", err
 	}
 
 	c, ok := token.Claims.(*packageClaims)
 	if !token.Valid || !ok {
-		return 0, fmt.Errorf("invalid token claim")
+		return 0, "", fmt.Errorf("invalid token claim")
 	}
 
-	return c.UserID, nil
+	return c.UserID, c.Scope, nil
 }
diff --git a/tests/integration/api_packages_conan_test.go b/tests/integration/api_packages_conan_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 	"time"
 
+	auth_model "code.gitea.io/gitea/models/auth"
 	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/packages"
 	conan_model "code.gitea.io/gitea/models/packages/conan"
@@ -224,6 +225,45 @@ func TestPackageConan(t *testing.T) {
 			assert.Equal(t, "revisions", resp.Header().Get("X-Conan-Server-Capabilities"))
 		})
 
+		t.Run("Token Scope Authentication", func(t *testing.T) {
+			defer tests.PrintCurrentTest(t)()
+
+			session := loginUser(t, user.Name)
+
+			testCase := func(t *testing.T, scope auth_model.AccessTokenScope, expectedStatusCode int) {
+				t.Helper()
+
+				token := getTokenForLoggedInUser(t, session, scope)
+
+				req := NewRequest(t, "GET", fmt.Sprintf("%s/v1/users/authenticate", url)).
+					AddTokenAuth(token)
+				resp := MakeRequest(t, req, http.StatusOK)
+
+				body := resp.Body.String()
+				assert.NotEmpty(t, body)
+
+				recipeURL := fmt.Sprintf("%s/v1/conans/%s/%s/%s/%s", url, "TestScope", version1, "testing", channel1)
+
+				req = NewRequestWithJSON(t, "POST", fmt.Sprintf("%s/upload_urls", recipeURL), map[string]int64{
+					conanfileName: 64,
+					"removed.txt": 0,
+				}).AddTokenAuth(token)
+				MakeRequest(t, req, expectedStatusCode)
+			}
+
+			t.Run("Read permission", func(t *testing.T) {
+				defer tests.PrintCurrentTest(t)()
+
+				testCase(t, auth_model.AccessTokenScopeReadPackage, http.StatusUnauthorized)
+			})
+
+			t.Run("Write permission", func(t *testing.T) {
+				defer tests.PrintCurrentTest(t)()
+
+				testCase(t, auth_model.AccessTokenScopeWritePackage, http.StatusOK)
+			})
+		})
+
 		token := ""
 
 		t.Run("Authenticate", func(t *testing.T) {
@@ -481,6 +521,43 @@ func TestPackageConan(t *testing.T) {
 
 		token := ""
 
+		t.Run("Token Scope Authentication", func(t *testing.T) {
+			defer tests.PrintCurrentTest(t)()
+
+			session := loginUser(t, user.Name)
+
+			testCase := func(t *testing.T, scope auth_model.AccessTokenScope, expectedStatusCode int) {
+				t.Helper()
+
+				token := getTokenForLoggedInUser(t, session, scope)
+
+				req := NewRequest(t, "GET", fmt.Sprintf("%s/v2/users/authenticate", url)).
+					AddTokenAuth(token)
+				resp := MakeRequest(t, req, http.StatusOK)
+
+				body := resp.Body.String()
+				assert.NotEmpty(t, body)
+
+				recipeURL := fmt.Sprintf("%s/v2/conans/%s/%s/%s/%s/revisions/%s", url, "TestScope", version1, "testing", channel1, revision1)
+
+				req = NewRequestWithBody(t, "PUT", fmt.Sprintf("%s/files/%s", recipeURL, conanfileName), strings.NewReader("Doesn't need to be valid")).
+					AddTokenAuth("Bearer " + body)
+				MakeRequest(t, req, expectedStatusCode)
+			}
+
+			t.Run("Read permission", func(t *testing.T) {
+				defer tests.PrintCurrentTest(t)()
+
+				testCase(t, auth_model.AccessTokenScopeReadPackage, http.StatusUnauthorized)
+			})
+
+			t.Run("Write permission", func(t *testing.T) {
+				defer tests.PrintCurrentTest(t)()
+
+				testCase(t, auth_model.AccessTokenScopeWritePackage, http.StatusCreated)
+			})
+		})
+
 		t.Run("Authenticate", func(t *testing.T) {
 			defer tests.PrintCurrentTest(t)()
 
@@ -512,7 +589,7 @@ func TestPackageConan(t *testing.T) {
 
 				pvs, err := packages.GetVersionsByPackageType(db.DefaultContext, user.ID, packages.TypeConan)
 				require.NoError(t, err)
-				assert.Len(t, pvs, 2)
+				assert.Len(t, pvs, 3)
 			})
 		})
 
diff --git a/tests/integration/api_packages_container_test.go b/tests/integration/api_packages_container_test.go
@@ -78,6 +78,7 @@ func TestPackageContainer(t *testing.T) {
 	indexManifestContent := `{"schemaVersion":2,"mediaType":"` + oci.MediaTypeImageIndex + `","manifests":[{"mediaType":"application/vnd.docker.distribution.manifest.v2+json","digest":"` + manifestDigest + `","platform":{"os":"linux","architecture":"arm","variant":"v7"}},{"mediaType":"` + oci.MediaTypeImageManifest + `","digest":"` + untaggedManifestDigest + `","platform":{"os":"linux","architecture":"arm64","variant":"v8"}}]}`
 
 	anonymousToken := ""
+	readUserToken := ""
 	userToken := ""
 
 	t.Run("Authenticate", func(t *testing.T) {
@@ -140,6 +141,30 @@ func TestPackageContainer(t *testing.T) {
 			req = NewRequest(t, "GET", fmt.Sprintf("%sv2", setting.AppURL)).
 				AddTokenAuth(userToken)
 			MakeRequest(t, req, http.StatusOK)
+
+			// Token that should enforce the read scope.
+			t.Run("Read scope", func(t *testing.T) {
+				defer tests.PrintCurrentTest(t)()
+
+				session := loginUser(t, user.Name)
+				token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeReadPackage)
+
+				req := NewRequest(t, "GET", fmt.Sprintf("%sv2/token", setting.AppURL))
+				req.SetBasicAuth(user.Name, token)
+
+				resp := MakeRequest(t, req, http.StatusOK)
+
+				tokenResponse := &TokenResponse{}
+				DecodeJSON(t, resp, &tokenResponse)
+
+				assert.NotEmpty(t, tokenResponse.Token)
+
+				readUserToken = fmt.Sprintf("Bearer %s", tokenResponse.Token)
+
+				req = NewRequest(t, "GET", fmt.Sprintf("%sv2", setting.AppURL)).
+					AddTokenAuth(readUserToken)
+				MakeRequest(t, req, http.StatusOK)
+			})
 		})
 	})
 
@@ -163,6 +188,10 @@ func TestPackageContainer(t *testing.T) {
 					AddTokenAuth(anonymousToken)
 				MakeRequest(t, req, http.StatusUnauthorized)
 
+				req = NewRequest(t, "POST", fmt.Sprintf("%s/blobs/uploads", url)).
+					AddTokenAuth(readUserToken)
+				MakeRequest(t, req, http.StatusUnauthorized)
+
 				req = NewRequestWithBody(t, "POST", fmt.Sprintf("%s/blobs/uploads?digest=%s", url, unknownDigest), bytes.NewReader(blobContent)).
 					AddTokenAuth(userToken)
 				MakeRequest(t, req, http.StatusBadRequest)
@@ -318,6 +347,11 @@ func TestPackageContainer(t *testing.T) {
 							SetHeader("Content-Type", "application/vnd.docker.distribution.manifest.v2+json")
 						MakeRequest(t, req, http.StatusUnauthorized)
 
+						req = NewRequestWithBody(t, "PUT", fmt.Sprintf("%s/manifests/%s", url, tag), strings.NewReader(manifestContent)).
+							AddTokenAuth(readUserToken).
+							SetHeader("Content-Type", "application/vnd.docker.distribution.manifest.v2+json")
+						MakeRequest(t, req, http.StatusUnauthorized)
+
 						req = NewRequestWithBody(t, "PUT", fmt.Sprintf("%s/manifests/%s", url, tag), strings.NewReader(manifestContent)).
 							AddTokenAuth(userToken).
 							SetHeader("Content-Type", "application/vnd.docker.distribution.manifest.v2+json")
@@ -521,6 +555,10 @@ func TestPackageContainer(t *testing.T) {
 				req = NewRequest(t, "HEAD", fmt.Sprintf("%s/blobs/%s", url, blobDigest)).
 					AddTokenAuth(anonymousToken)
 				MakeRequest(t, req, http.StatusOK)
+
+				req = NewRequest(t, "HEAD", fmt.Sprintf("%s/blobs/%s", url, blobDigest)).
+					AddTokenAuth(readUserToken)
+				MakeRequest(t, req, http.StatusOK)
 			})
 
 			t.Run("GetBlob", func(t *testing.T) {

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+The scope of application tokens is not verified when writing containers or Conan packages. This is of no consequence when the user associated with the application token does not have write access to packages. If the user has write access to packages, such a token can be used to write containers and Conan packages.`