Parse role claims (#7713)

* extract and test role claim parsing

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

* add failing test

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

* read segmented roles claim as array and string

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

* reuse more code by extracting WalkSegments

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

* add TestSplitWithEscaping

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

* docs and error for unhandled case

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

* add claims test

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

* add missing ReadStringClaim docs

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

---------

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

ocis-pkg/oidc/claims.go

@@ -1,5 +1,10 @@
 package oidc
 
+import (
+	"fmt"
+	"strings"
+)
+
 const (
 	Iss               = "iss"
 	Sub               = "sub"
@@ -12,3 +17,60 @@ const (
 	OwncloudUUID      = "ownclouduuid"
 	OcisRoutingPolicy = "ocis.routing.policy"
 )
+
+// SplitWithEscaping splits s into segments using separator which can be escaped using the escape string
+// See https://codereview.stackexchange.com/a/280193
+func SplitWithEscaping(s string, separator string, escapeString string) []string {
+	a := strings.Split(s, separator)
+
+	for i := len(a) - 2; i >= 0; i-- {
+		if strings.HasSuffix(a[i], escapeString) {
+			a[i] = a[i][:len(a[i])-len(escapeString)] + separator + a[i+1]
+			a = append(a[:i+1], a[i+2:]...)
+		}
+	}
+	return a
+}
+
+// WalkSegments uses the given array of segments to walk the claims and return whatever interface was found
+func WalkSegments(segments []string, claims map[string]interface{}) (interface{}, error) {
+	i := 0
+	for ; i < len(segments)-1; i++ {
+		switch castedClaims := claims[segments[i]].(type) {
+		case map[string]interface{}:
+			claims = castedClaims
+		case map[interface{}]interface{}:
+			claims = make(map[string]interface{}, len(castedClaims))
+			for k, v := range castedClaims {
+				if s, ok := k.(string); ok {
+					claims[s] = v
+				} else {
+					return nil, fmt.Errorf("could not walk claims path, key '%v' is not a string", k)
+				}
+			}
+		default:
+			return nil, fmt.Errorf("unsupported type '%v'", castedClaims)
+		}
+	}
+	return claims[segments[i]], nil
+}
+
+// ReadStringClaim returns the string obtained by following the . seperated path in the claims
+func ReadStringClaim(path string, claims map[string]interface{}) (string, error) {
+	// check the simple case first
+	value, _ := claims[path].(string)
+	if value != "" {
+		return value, nil
+	}
+
+	claim, err := WalkSegments(SplitWithEscaping(path, ".", "\\"), claims)
+	if err != nil {
+		return "", err
+	}
+
+	if value, _ = claim.(string); value != "" {
+		return value, nil
+	}
+
+	return value, fmt.Errorf("claim path '%s' not set or empty", path)
+}

ocis-pkg/oidc/claims_test.go

@@ -0,0 +1,182 @@
+package oidc_test
+
+import (
+	"encoding/json"
+	"reflect"
+	"testing"
+
+	"github.com/owncloud/ocis/v2/ocis-pkg/oidc"
+)
+
+type splitWithEscapingTest struct {
+	// Name of the subtest.
+	name string
+
+	// string to split
+	s string
+
+	// seperator to use
+	seperator string
+
+	// escape character to use for escaping
+	escape string
+
+	expectedParts []string
+}
+
+func (swet splitWithEscapingTest) run(t *testing.T) {
+	parts := oidc.SplitWithEscaping(swet.s, swet.seperator, swet.escape)
+	if len(swet.expectedParts) != len(parts) {
+		t.Errorf("mismatching length")
+	}
+	for i, v := range swet.expectedParts {
+		if parts[i] != v {
+			t.Errorf("expected part %d to be '%s', got '%s'", i, v, parts[i])
+		}
+	}
+}
+
+func TestSplitWithEscaping(t *testing.T) {
+	tests := []splitWithEscapingTest{
+		{
+			name:          "plain claim name",
+			s:             "roles",
+			seperator:     ".",
+			escape:        "\\",
+			expectedParts: []string{"roles"},
+		},
+		{
+			name:          "claim with .",
+			s:             "my.roles",
+			seperator:     ".",
+			escape:        "\\",
+			expectedParts: []string{"my", "roles"},
+		},
+		{
+			name:          "claim with escaped .",
+			s:             "my\\.roles",
+			seperator:     ".",
+			escape:        "\\",
+			expectedParts: []string{"my.roles"},
+		},
+		{
+			name:          "claim with escaped . left",
+			s:             "my\\.other.roles",
+			seperator:     ".",
+			escape:        "\\",
+			expectedParts: []string{"my.other", "roles"},
+		},
+		{
+			name:          "claim with escaped . right",
+			s:             "my.other\\.roles",
+			seperator:     ".",
+			escape:        "\\",
+			expectedParts: []string{"my", "other.roles"},
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, test.run)
+	}
+}
+
+type walkSegmentsTest struct {
+	// Name of the subtest.
+	name string
+
+	// path segments to walk
+	segments []string
+
+	// seperator to use
+	claims map[string]interface{}
+
+	expected interface{}
+
+	wantErr bool
+}
+
+func (wst walkSegmentsTest) run(t *testing.T) {
+	v, err := oidc.WalkSegments(wst.segments, wst.claims)
+	if err != nil && !wst.wantErr {
+		t.Errorf("%v", err)
+	}
+	if err == nil && wst.wantErr {
+		t.Errorf("expected error")
+	}
+	if !reflect.DeepEqual(v, wst.expected) {
+		t.Errorf("expected %v got %v", wst.expected, v)
+	}
+}
+
+func TestWalkSegments(t *testing.T) {
+	byt := []byte(`{"first":{"second":{"third":["value1","value2"]},"foo":"bar"},"fizz":"buzz"}`)
+	var dat map[string]interface{}
+	if err := json.Unmarshal(byt, &dat); err != nil {
+		t.Errorf("%v", err)
+	}
+
+	tests := []walkSegmentsTest{
+		{
+			name:     "one segment, single value",
+			segments: []string{"first"},
+			claims: map[string]interface{}{
+				"first": "value",
+			},
+			expected: "value",
+			wantErr:  false,
+		},
+		{
+			name:     "one segment, array value",
+			segments: []string{"first"},
+			claims: map[string]interface{}{
+				"first": []string{"value1", "value2"},
+			},
+			expected: []string{"value1", "value2"},
+			wantErr:  false,
+		},
+		{
+			name:     "two segments, single value",
+			segments: []string{"first", "second"},
+			claims: map[string]interface{}{
+				"first": map[string]interface{}{
+					"second": "value",
+				},
+			},
+			expected: "value",
+			wantErr:  false,
+		},
+		{
+			name:     "two segments, array value",
+			segments: []string{"first", "second"},
+			claims: map[string]interface{}{
+				"first": map[string]interface{}{
+					"second": []string{"value1", "value2"},
+				},
+			},
+			expected: []string{"value1", "value2"},
+			wantErr:  false,
+		},
+		{
+			name:     "three segments, array value from json",
+			segments: []string{"first", "second", "third"},
+			claims:   dat,
+			expected: []interface{}{"value1", "value2"},
+			wantErr:  false,
+		},
+		{
+			name:     "three segments, array value with interface key",
+			segments: []string{"first", "second", "third"},
+			claims: map[string]interface{}{
+				"first": map[interface{}]interface{}{
+					"second": map[interface{}]interface{}{
+						"third": []string{"value1", "value2"},
+					},
+				},
+			},
+			expected: []string{"value1", "value2"},
+			wantErr:  false,
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, test.run)
+	}
+}

services/proxy/pkg/middleware/account_resolver.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
-	"strings"
 
 	"github.com/owncloud/ocis/v2/services/proxy/pkg/user/backend"
 	"github.com/owncloud/ocis/v2/services/proxy/pkg/userroles"
@@ -43,19 +42,6 @@ type accountResolver struct {
 	userCS3Claim          string
 }
 
-// from https://codereview.stackexchange.com/a/280193
-func splitWithEscaping(s string, separator string, escapeString string) []string {
-	a := strings.Split(s, separator)
-
-	for i := len(a) - 2; i >= 0; i-- {
-		if strings.HasSuffix(a[i], escapeString) {
-			a[i] = a[i][:len(a[i])-len(escapeString)] + separator + a[i+1]
-			a = append(a[:i+1], a[i+2:]...)
-		}
-	}
-	return a
-}
-
 func readUserIDClaim(path string, claims map[string]interface{}) (string, error) {
 	// happy path
 	value, _ := claims[path].(string)
@@ -64,7 +50,7 @@ func readUserIDClaim(path string, claims map[string]interface{}) (string, error)
 	}
 
 	// try splitting path at .
-	segments := splitWithEscaping(path, ".", "\\")
+	segments := oidc.SplitWithEscaping(path, ".", "\\")
 	subclaims := claims
 	lastSegment := len(segments) - 1
 	for i := range segments {

services/proxy/pkg/userroles/oidcroles.go

@@ -9,6 +9,7 @@ import (
 	cs3 "github.com/cs3org/go-cs3apis/cs3/identity/user/v1beta1"
 	"github.com/cs3org/reva/v2/pkg/utils"
 	"github.com/owncloud/ocis/v2/ocis-pkg/middleware"
+	"github.com/owncloud/ocis/v2/ocis-pkg/oidc"
 	settingssvc "github.com/owncloud/ocis/v2/protogen/gen/ocis/services/settings/v0"
 	"go-micro.dev/v4/metadata"
 )
@@ -29,6 +30,45 @@ func NewOIDCRoleAssigner(opts ...Option) UserRoleAssigner {
 	}
 }
 
+func extractRoles(rolesClaim string, claims map[string]interface{}) (map[string]struct{}, error) {
+
+	claimRoles := map[string]struct{}{}
+	// happy path
+	value, _ := claims[rolesClaim].(string)
+	if value != "" {
+		claimRoles[value] = struct{}{}
+		return claimRoles, nil
+	}
+
+	claim, err := oidc.WalkSegments(oidc.SplitWithEscaping(rolesClaim, ".", "\\"), claims)
+	if err != nil {
+		return nil, err
+	}
+
+	switch v := claim.(type) {
+	case []string:
+		for _, cr := range v {
+			claimRoles[cr] = struct{}{}
+		}
+	case []interface{}:
+		for _, cri := range v {
+			cr, ok := cri.(string)
+			if !ok {
+				err := errors.New("invalid role in claims")
+				return nil, err
+			}
+
+			claimRoles[cr] = struct{}{}
+		}
+	case string:
+		claimRoles[v] = struct{}{}
+	default:
+		return nil, errors.New("no roles in user claims")
+	}
+
+	return claimRoles, nil
+}
+
 // UpdateUserRoleAssignment assigns the role "User" to the supplied user. Unless the user
 // already has a different role assigned.
 func (ra oidcRoleAssigner) UpdateUserRoleAssignment(ctx context.Context, user *cs3.User, claims map[string]interface{}) (*cs3.User, error) {
@@ -39,23 +79,10 @@ func (ra oidcRoleAssigner) UpdateUserRoleAssignment(ctx context.Context, user *c
 		return nil, err
 	}
 
-	claimRolesRaw, ok := claims[ra.rolesClaim].([]interface{})
-	if !ok {
-		logger.Error().Str("rolesClaim", ra.rolesClaim).Msg("No roles in user claims")
-		return nil, errors.New("no roles in user claims")
-	}
-
-	logger.Debug().Str("rolesClaim", ra.rolesClaim).Interface("rolesInClaim", claims[ra.rolesClaim]).Msg("got roles in claim")
-	claimRoles := map[string]struct{}{}
-	for _, cri := range claimRolesRaw {
-		cr, ok := cri.(string)
-		if !ok {
-			err := errors.New("invalid role in claims")
-			logger.Error().Err(err).Interface("claimValue", cri).Msg("Is not a valid string.")
-			return nil, err
-		}
-
-		claimRoles[cr] = struct{}{}
+	claimRoles, err := extractRoles(ra.rolesClaim, claims)
+	if err != nil {
+		logger.Error().Err(err).Msg("Error mapping role names to role ids")
+		return nil, err
 	}
 
 	if len(claimRoles) == 0 {