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

- 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 #5128

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.

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)

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

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)

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

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
 }

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)
 			})
 		})
 

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) {