package handler import ( "context" "crypto/ecdsa" "crypto/elliptic" "encoding/hex" "encoding/json" "encoding/xml" stderrors "errors" "fmt" "net/http" "strings" "github.com/nspcc-dev/neo-go/pkg/crypto/keys" v2acl "github.com/nspcc-dev/neofs-api-go/v2/acl" "github.com/nspcc-dev/neofs-s3-gw/api" "github.com/nspcc-dev/neofs-s3-gw/api/data" "github.com/nspcc-dev/neofs-s3-gw/api/errors" "github.com/nspcc-dev/neofs-s3-gw/api/layer" "github.com/nspcc-dev/neofs-sdk-go/eacl" "github.com/nspcc-dev/neofs-sdk-go/object" oid "github.com/nspcc-dev/neofs-sdk-go/object/id" "github.com/nspcc-dev/neofs-sdk-go/session" "go.uber.org/zap" ) var ( writeOps = []eacl.Operation{eacl.OperationPut, eacl.OperationDelete} readOps = []eacl.Operation{eacl.OperationGet, eacl.OperationHead, eacl.OperationSearch, eacl.OperationRange, eacl.OperationRangeHash} fullOps = []eacl.Operation{eacl.OperationGet, eacl.OperationHead, eacl.OperationPut, eacl.OperationDelete, eacl.OperationSearch, eacl.OperationRange, eacl.OperationRangeHash} ) var actionToOpMap = map[string][]eacl.Operation{ s3DeleteObject: {eacl.OperationDelete}, s3GetObject: readOps, s3PutObject: {eacl.OperationPut}, s3ListBucket: readOps, } const ( arnAwsPrefix = "arn:aws:s3:::" allUsersWildcard = "*" allUsersGroup = "http://acs.amazonaws.com/groups/global/AllUsers" s3DeleteObject = "s3:DeleteObject" s3GetObject = "s3:GetObject" s3PutObject = "s3:PutObject" s3ListBucket = "s3:ListBucket" s3ListBucketVersions = "s3:ListBucketVersions" s3ListBucketMultipartUploads = "s3:ListBucketMultipartUploads" s3GetObjectVersion = "s3:GetObjectVersion" ) // AWSACL is aws permission constants. type AWSACL string const ( aclFullControl AWSACL = "FULL_CONTROL" aclWrite AWSACL = "WRITE" aclRead AWSACL = "READ" ) // GranteeType is aws grantee permission type constants. type GranteeType string const ( acpCanonicalUser GranteeType = "CanonicalUser" acpAmazonCustomerByEmail GranteeType = "AmazonCustomerByEmail" acpGroup GranteeType = "Group" ) type bucketPolicy struct { Version string `json:"Version"` ID string `json:"Id"` Statement []statement `json:"Statement"` Bucket string `json:"-"` } type statement struct { Sid string `json:"Sid"` Effect string `json:"Effect"` Principal principal `json:"Principal"` Action []string `json:"Action"` Resource []string `json:"Resource"` } type principal struct { AWS string `json:"AWS,omitempty"` CanonicalUser string `json:"CanonicalUser,omitempty"` } type ast struct { Resources []*astResource } type astResource struct { resourceInfo Operations []*astOperation } type resourceInfo struct { Bucket string Object string Version string } func (r *resourceInfo) Name() string { if len(r.Object) == 0 { return r.Bucket } if len(r.Version) == 0 { return r.Bucket + "/" + r.Object } return r.Bucket + "/" + r.Object + ":" + r.Version } func (r *resourceInfo) IsBucket() bool { return len(r.Object) == 0 } type astOperation struct { Users []string Op eacl.Operation Action eacl.Action } func (a astOperation) IsGroupGrantee() bool { return len(a.Users) == 0 } func (h *handler) GetBucketACLHandler(w http.ResponseWriter, r *http.Request) { reqInfo := api.GetReqInfo(r.Context()) bktInfo, err := h.getBucketAndCheckOwner(r, reqInfo.BucketName) if err != nil { h.logAndSendError(w, "could not get bucket info", reqInfo, err) return } bucketACL, err := h.obj.GetBucketACL(r.Context(), bktInfo) if err != nil { h.logAndSendError(w, "could not fetch bucket acl", reqInfo, err) return } if err = api.EncodeToResponse(w, h.encodeBucketACL(bucketACL)); err != nil { h.logAndSendError(w, "something went wrong", reqInfo, err) return } } func (h *handler) bearerTokenIssuerKey(ctx context.Context) (*keys.PublicKey, error) { box, err := layer.GetBoxData(ctx) if err != nil { return nil, err } var btoken v2acl.BearerToken box.Gate.BearerToken.WriteToV2(&btoken) key, err := keys.NewPublicKeyFromBytes(btoken.GetSignature().GetKey(), elliptic.P256()) if err != nil { return nil, fmt.Errorf("public key from bytes: %w", err) } return key, nil } func (h *handler) PutBucketACLHandler(w http.ResponseWriter, r *http.Request) { reqInfo := api.GetReqInfo(r.Context()) key, err := h.bearerTokenIssuerKey(r.Context()) if err != nil { h.logAndSendError(w, "couldn't get bearer token issuer key", reqInfo, err) return } token, err := getSessionTokenSetEACL(r.Context()) if err != nil { h.logAndSendError(w, "couldn't get eacl token", reqInfo, err) return } list := &AccessControlPolicy{} if r.ContentLength == 0 { list, err = parseACLHeaders(r.Header, key) if err != nil { h.logAndSendError(w, "could not parse bucket acl", reqInfo, err) return } } else if err = xml.NewDecoder(r.Body).Decode(list); err != nil { h.logAndSendError(w, "could not parse bucket acl", reqInfo, errors.GetAPIError(errors.ErrMalformedXML)) return } resInfo := &resourceInfo{Bucket: reqInfo.BucketName} astBucket, err := aclToAst(list, resInfo) if err != nil { h.logAndSendError(w, "could not translate acl to policy", reqInfo, err) return } bktInfo, err := h.getBucketAndCheckOwner(r, reqInfo.BucketName) if err != nil { h.logAndSendError(w, "could not get bucket info", reqInfo, err) return } if _, err = h.updateBucketACL(r, astBucket, bktInfo, token); err != nil { h.logAndSendError(w, "could not update bucket acl", reqInfo, err) return } w.WriteHeader(http.StatusOK) } func (h *handler) updateBucketACL(r *http.Request, astChild *ast, bktInfo *data.BucketInfo, sessionToken *session.Container) (bool, error) { bucketACL, err := h.obj.GetBucketACL(r.Context(), bktInfo) if err != nil { return false, fmt.Errorf("could not get bucket eacl: %w", err) } parentAst := tableToAst(bucketACL.EACL, bktInfo.Name) strCID := bucketACL.Info.CID.EncodeToString() for _, resource := range parentAst.Resources { if resource.Bucket == strCID { resource.Bucket = bktInfo.Name } } resAst, updated := mergeAst(parentAst, astChild) if !updated { return false, nil } table, err := astToTable(resAst) if err != nil { return false, fmt.Errorf("could not translate ast to table: %w", err) } p := &layer.PutBucketACLParams{ BktInfo: bktInfo, EACL: table, SessionToken: sessionToken, } if err = h.obj.PutBucketACL(r.Context(), p); err != nil { return false, fmt.Errorf("could not put bucket acl: %w", err) } return true, nil } func (h *handler) GetObjectACLHandler(w http.ResponseWriter, r *http.Request) { reqInfo := api.GetReqInfo(r.Context()) bktInfo, err := h.getBucketAndCheckOwner(r, reqInfo.BucketName) if err != nil { h.logAndSendError(w, "could not get bucket info", reqInfo, err) return } bucketACL, err := h.obj.GetBucketACL(r.Context(), bktInfo) if err != nil { h.logAndSendError(w, "could not fetch bucket acl", reqInfo, err) return } if err = api.EncodeToResponse(w, h.encodeObjectACL(bucketACL, reqInfo.ObjectName)); err != nil { h.logAndSendError(w, "something went wrong", reqInfo, err) } } func (h *handler) PutObjectACLHandler(w http.ResponseWriter, r *http.Request) { reqInfo := api.GetReqInfo(r.Context()) versionID := reqInfo.URL.Query().Get(api.QueryVersionID) key, err := h.bearerTokenIssuerKey(r.Context()) if err != nil { h.logAndSendError(w, "couldn't get gate key", reqInfo, err) return } token, err := getSessionTokenSetEACL(r.Context()) if err != nil { h.logAndSendError(w, "couldn't get eacl token", reqInfo, err) return } list := &AccessControlPolicy{} if r.ContentLength == 0 { list, err = parseACLHeaders(r.Header, key) if err != nil { h.logAndSendError(w, "could not parse bucket acl", reqInfo, err) return } } else if err = xml.NewDecoder(r.Body).Decode(list); err != nil { h.logAndSendError(w, "could not parse bucket acl", reqInfo, errors.GetAPIError(errors.ErrMalformedXML)) return } resInfo := &resourceInfo{ Bucket: reqInfo.BucketName, Object: reqInfo.ObjectName, Version: versionID, } astObject, err := aclToAst(list, resInfo) if err != nil { h.logAndSendError(w, "could not translate acl to ast", reqInfo, err) return } bktInfo, err := h.getBucketAndCheckOwner(r, reqInfo.BucketName) if err != nil { h.logAndSendError(w, "could not get bucket info", reqInfo, err) return } p := &layer.HeadObjectParams{ BktInfo: bktInfo, Object: reqInfo.ObjectName, VersionID: versionID, } objInfo, err := h.obj.GetObjectInfo(r.Context(), p) if err != nil { h.logAndSendError(w, "could not get object info", reqInfo, err) return } updated, err := h.updateBucketACL(r, astObject, bktInfo, token) if err != nil { h.logAndSendError(w, "could not update bucket acl", reqInfo, err) return } if updated { s := &SendNotificationParams{ Event: EventObjectACLPut, ObjInfo: objInfo, BktInfo: bktInfo, ReqInfo: reqInfo, } if err = h.sendNotifications(r.Context(), s); err != nil { h.log.Error("couldn't send notification: %w", zap.Error(err)) } } w.WriteHeader(http.StatusOK) } func (h *handler) GetBucketPolicyHandler(w http.ResponseWriter, r *http.Request) { reqInfo := api.GetReqInfo(r.Context()) bktInfo, err := h.getBucketAndCheckOwner(r, reqInfo.BucketName) if err != nil { h.logAndSendError(w, "could not get bucket info", reqInfo, err) return } bucketACL, err := h.obj.GetBucketACL(r.Context(), bktInfo) if err != nil { h.logAndSendError(w, "could not fetch bucket acl", reqInfo, err) return } ast := tableToAst(bucketACL.EACL, reqInfo.BucketName) bktPolicy := astToPolicy(ast) w.WriteHeader(http.StatusOK) if err = json.NewEncoder(w).Encode(bktPolicy); err != nil { h.logAndSendError(w, "something went wrong", reqInfo, err) } } func checkOwner(info *data.BucketInfo, owner string) error { if owner == "" { return nil } // may need to convert owner to appropriate format if info.Owner.String() != owner { return errors.GetAPIError(errors.ErrAccessDenied) } return nil } func (h *handler) PutBucketPolicyHandler(w http.ResponseWriter, r *http.Request) { reqInfo := api.GetReqInfo(r.Context()) bktInfo, err := h.getBucketAndCheckOwner(r, reqInfo.BucketName) if err != nil { h.logAndSendError(w, "could not get bucket info", reqInfo, err) return } token, err := getSessionTokenSetEACL(r.Context()) if err != nil { h.logAndSendError(w, "couldn't get eacl token", reqInfo, err) return } bktPolicy := &bucketPolicy{Bucket: reqInfo.BucketName} if err = json.NewDecoder(r.Body).Decode(bktPolicy); err != nil { h.logAndSendError(w, "could not parse bucket policy", reqInfo, err) return } astPolicy, err := policyToAst(bktPolicy) if err != nil { h.logAndSendError(w, "could not translate policy to ast", reqInfo, err) return } if _, err = h.updateBucketACL(r, astPolicy, bktInfo, token); err != nil { h.logAndSendError(w, "could not update bucket acl", reqInfo, err) return } } func parseACLHeaders(header http.Header, key *keys.PublicKey) (*AccessControlPolicy, error) { var err error acp := &AccessControlPolicy{Owner: Owner{ ID: hex.EncodeToString(key.Bytes()), DisplayName: key.Address(), }} acp.AccessControlList = []*Grant{{ Grantee: &Grantee{ ID: hex.EncodeToString(key.Bytes()), DisplayName: key.Address(), Type: acpCanonicalUser, }, Permission: aclFullControl, }} cannedACL := header.Get(api.AmzACL) if cannedACL != "" { return addPredefinedACP(acp, cannedACL) } if acp.AccessControlList, err = addGrantees(acp.AccessControlList, header, api.AmzGrantFullControl); err != nil { return nil, fmt.Errorf("add grantees full control: %w", err) } if acp.AccessControlList, err = addGrantees(acp.AccessControlList, header, api.AmzGrantRead); err != nil { return nil, fmt.Errorf("add grantees read: %w", err) } if acp.AccessControlList, err = addGrantees(acp.AccessControlList, header, api.AmzGrantWrite); err != nil { return nil, fmt.Errorf("add grantees write: %w", err) } return acp, nil } func addGrantees(list []*Grant, headers http.Header, hdr string) ([]*Grant, error) { grant := headers.Get(hdr) if grant == "" { return list, nil } permission, err := grantHdrToPermission(hdr) if err != nil { return nil, fmt.Errorf("parse header: %w", err) } grantees, err := parseGrantee(grant) if err != nil { return nil, fmt.Errorf("parse grantee: %w", err) } for _, grantee := range grantees { if grantee.Type == acpAmazonCustomerByEmail || (grantee.Type == acpGroup && grantee.URI != allUsersGroup) { return nil, stderrors.New("unsupported grantee type") } list = append(list, &Grant{ Grantee: grantee, Permission: permission, }) } return list, nil } func grantHdrToPermission(grant string) (AWSACL, error) { switch grant { case api.AmzGrantFullControl: return aclFullControl, nil case api.AmzGrantRead: return aclRead, nil case api.AmzGrantWrite: return aclWrite, nil } return "", fmt.Errorf("unsuppoted header: %s", grant) } func parseGrantee(grantees string) ([]*Grantee, error) { var result []*Grantee split := strings.Split(grantees, ", ") for _, pair := range split { split2 := strings.Split(pair, "=") if len(split2) != 2 { return nil, errors.GetAPIError(errors.ErrInvalidArgument) } grantee, err := formGrantee(split2[0], split2[1]) if err != nil { return nil, fmt.Errorf("form grantee: %w", err) } result = append(result, grantee) } return result, nil } func formGrantee(granteeType, value string) (*Grantee, error) { value = strings.Trim(value, "\"") switch granteeType { case "id": return &Grantee{ ID: value, Type: acpCanonicalUser, }, nil case "uri": return &Grantee{ URI: value, Type: acpGroup, }, nil case "emailAddress": return &Grantee{ EmailAddress: value, Type: acpAmazonCustomerByEmail, }, nil } // do not return grantee type to avoid sensitive data logging (#489) return nil, fmt.Errorf("unknown grantee type") } func addPredefinedACP(acp *AccessControlPolicy, cannedACL string) (*AccessControlPolicy, error) { switch cannedACL { case basicACLPrivate: case basicACLPublic: acp.AccessControlList = append(acp.AccessControlList, &Grant{ Grantee: &Grantee{ URI: allUsersGroup, Type: acpGroup, }, Permission: aclFullControl, }) case cannedACLAuthRead: fallthrough case basicACLReadOnly: acp.AccessControlList = append(acp.AccessControlList, &Grant{ Grantee: &Grantee{ URI: allUsersGroup, Type: acpGroup, }, Permission: aclRead, }) default: return nil, errors.GetAPIError(errors.ErrInvalidArgument) } return acp, nil } func tableToAst(table *eacl.Table, bktName string) *ast { result := &ast{} metResources := make(map[string]int) for i := len(table.Records()) - 1; i >= 0; i-- { resName := bktName var objectName string var version string record := table.Records()[i] for _, filter := range record.Filters() { if filter.Matcher() == eacl.MatchStringEqual { if filter.Key() == object.AttributeFileName { objectName = filter.Value() resName += "/" + objectName } else if filter.Key() == v2acl.FilterObjectID { version = filter.Value() resName += "/" + version } } } idx, ok := metResources[resName] if !ok { resource := &astResource{resourceInfo: resourceInfo{ Bucket: bktName, Object: objectName, Version: version, }} result.Resources = append(result.Resources, resource) idx = len(result.Resources) - 1 metResources[resName] = idx } for _, target := range record.Targets() { result.Resources[idx].Operations = addToList(result.Resources[idx].Operations, record, target) } } for _, res := range result.Resources { for i, j := 0, len(res.Operations)-1; i < j; i, j = i+1, j-1 { res.Operations[i], res.Operations[j] = res.Operations[j], res.Operations[i] } } return result } func mergeAst(parent, child *ast) (*ast, bool) { updated := false for _, resource := range child.Resources { parentResource := getParentResource(parent, resource) if parentResource == nil { parent.Resources = append(parent.Resources, resource) updated = true continue } var newOps []*astOperation for _, astOp := range resource.Operations { ops := getAstOps(parentResource, astOp) switch len(ops) { case 2: // potential inconsistency if groupGrantee := astOp.IsGroupGrantee(); groupGrantee { // it is not likely (such state must be detected early) // inconsistency action := eacl.ActionAllow if astOp.Action == eacl.ActionAllow { action = eacl.ActionDeny } removeAstOp(parentResource, groupGrantee, astOp.Op, action) updated = true continue } opToAdd, opToDelete := ops[0], ops[1] if ops[1].Action == astOp.Action { opToAdd, opToDelete = ops[1], ops[0] } if handleAddOperations(parentResource, astOp, opToAdd) { updated = true } if handleRemoveOperations(parentResource, astOp, opToDelete) { updated = true } case 1: if astOp.Action != ops[0].Action { // potential inconsistency if groupGrantee := astOp.IsGroupGrantee(); groupGrantee { // inconsistency removeAstOp(parentResource, groupGrantee, astOp.Op, ops[0].Action) parentResource.Operations = append(parentResource.Operations, astOp) updated = true continue } if handleRemoveOperations(parentResource, astOp, ops[0]) { updated = true } parentResource.Operations = append(parentResource.Operations, astOp) continue } if handleAddOperations(parentResource, astOp, ops[0]) { updated = true } case 0: newOps = append(newOps, astOp) updated = true } } if newOps != nil { parentResource.Operations = append(newOps, parentResource.Operations...) } } return parent, updated } func handleAddOperations(parentResource *astResource, astOp, existedOp *astOperation) bool { var needToAdd []string for _, user := range astOp.Users { if !containsStr(existedOp.Users, user) { needToAdd = append(needToAdd, user) } } if len(needToAdd) != 0 { addUsers(parentResource, existedOp, needToAdd) return true } return false } func handleRemoveOperations(parentResource *astResource, astOp, existedOp *astOperation) bool { var needToRemove []string for _, user := range astOp.Users { if containsStr(existedOp.Users, user) { needToRemove = append(needToRemove, user) } } if len(needToRemove) != 0 { removeUsers(parentResource, existedOp, needToRemove) return true } return false } func containsStr(list []string, element string) bool { for _, str := range list { if str == element { return true } } return false } func getAstOps(resource *astResource, childOp *astOperation) []*astOperation { var res []*astOperation for _, astOp := range resource.Operations { if astOp.IsGroupGrantee() == childOp.IsGroupGrantee() && astOp.Op == childOp.Op { res = append(res, astOp) } } return res } func removeAstOp(resource *astResource, group bool, op eacl.Operation, action eacl.Action) { for i, astOp := range resource.Operations { if astOp.IsGroupGrantee() == group && astOp.Op == op && astOp.Action == action { resource.Operations = append(resource.Operations[:i], resource.Operations[i+1:]...) return } } } func addUsers(resource *astResource, astO *astOperation, users []string) { for _, astOp := range resource.Operations { if astOp.IsGroupGrantee() == astO.IsGroupGrantee() && astOp.Op == astO.Op && astOp.Action == astO.Action { astOp.Users = append(astO.Users, users...) return } } } func removeUsers(resource *astResource, astOperation *astOperation, users []string) { for ind, astOp := range resource.Operations { if !astOp.IsGroupGrantee() && astOp.Op == astOperation.Op && astOp.Action == astOperation.Action { filteredUsers := astOp.Users[:0] // new slice without allocation for _, user := range astOp.Users { if !containsStr(users, user) { filteredUsers = append(filteredUsers, user) } } if len(filteredUsers) == 0 { // remove ast resource resource.Operations = append(resource.Operations[:ind], resource.Operations[ind+1:]...) } else { astOp.Users = filteredUsers } return } } } func getParentResource(parent *ast, resource *astResource) *astResource { for _, parentResource := range parent.Resources { if resource.Bucket == parentResource.Bucket && resource.Object == parentResource.Object && resource.Version == parentResource.Version { return parentResource } } return nil } func astToTable(ast *ast) (*eacl.Table, error) { table := eacl.NewTable() for i := len(ast.Resources) - 1; i >= 0; i-- { records, err := formRecords(ast.Resources[i].Operations, ast.Resources[i]) if err != nil { return nil, fmt.Errorf("form records: %w", err) } for _, rec := range records { table.AddRecord(rec) } } return table, nil } func formRecords(operations []*astOperation, resource *astResource) ([]*eacl.Record, error) { var res []*eacl.Record for _, astOp := range operations { record := eacl.NewRecord() record.SetOperation(astOp.Op) record.SetAction(astOp.Action) if astOp.IsGroupGrantee() { eacl.AddFormedTarget(record, eacl.RoleOthers) } else { targetKeys := make([]ecdsa.PublicKey, 0, len(astOp.Users)) for _, user := range astOp.Users { pk, err := keys.NewPublicKeyFromString(user) if err != nil { return nil, fmt.Errorf("public key from string: %w", err) } targetKeys = append(targetKeys, (ecdsa.PublicKey)(*pk)) } // Unknown role is used, because it is ignored when keys are set eacl.AddFormedTarget(record, eacl.RoleUnknown, targetKeys...) } if len(resource.Object) != 0 { if len(resource.Version) != 0 { var id oid.ID if err := id.DecodeString(resource.Version); err != nil { return nil, fmt.Errorf("parse object version (oid): %w", err) } record.AddObjectIDFilter(eacl.MatchStringEqual, id) } else { record.AddObjectAttributeFilter(eacl.MatchStringEqual, object.AttributeFileName, resource.Object) } } res = append(res, record) } return res, nil } func addToList(operations []*astOperation, rec eacl.Record, target eacl.Target) []*astOperation { var ( found *astOperation groupTarget = target.Role() == eacl.RoleOthers ) for _, astOp := range operations { if astOp.Op == rec.Operation() && astOp.IsGroupGrantee() == groupTarget { found = astOp } } if found != nil { if !groupTarget { for _, key := range target.BinaryKeys() { found.Users = append(found.Users, hex.EncodeToString(key)) } } } else { astOperation := &astOperation{ Op: rec.Operation(), Action: rec.Action(), } if !groupTarget { for _, key := range target.BinaryKeys() { astOperation.Users = append(astOperation.Users, hex.EncodeToString(key)) } } operations = append(operations, astOperation) } return operations } func policyToAst(bktPolicy *bucketPolicy) (*ast, error) { res := &ast{} rr := make(map[string]*astResource) for _, state := range bktPolicy.Statement { if state.Principal.AWS != "" && state.Principal.AWS != allUsersWildcard || state.Principal.AWS == "" && state.Principal.CanonicalUser == "" { return nil, fmt.Errorf("unsupported principal: %v", state.Principal) } var groupGrantee bool if state.Principal.AWS == allUsersWildcard { groupGrantee = true } for _, resource := range state.Resource { trimmedResource := strings.TrimPrefix(resource, arnAwsPrefix) r, ok := rr[trimmedResource] if !ok { r = &astResource{resourceInfo: resourceInfo{Bucket: bktPolicy.Bucket}} if trimmedResource != bktPolicy.Bucket { versionedObject := strings.TrimPrefix(trimmedResource, bktPolicy.Bucket+"/") objVersion := strings.Split(versionedObject, ":") if len(objVersion) <= 2 { r.Object = objVersion[0] if len(objVersion) == 2 { r.Version = objVersion[1] } } else { r.Object = strings.Join(objVersion[:len(objVersion)-1], ":") r.Version = objVersion[len(objVersion)-1] } } } for _, action := range state.Action { for _, op := range actionToOpMap[action] { toAction := effectToAction(state.Effect) r.Operations = addTo(r.Operations, state.Principal.CanonicalUser, op, groupGrantee, toAction) } } rr[trimmedResource] = r } } for _, val := range rr { res.Resources = append(res.Resources, val) } return res, nil } func astToPolicy(ast *ast) *bucketPolicy { bktPolicy := &bucketPolicy{} for _, resource := range ast.Resources { if len(resource.Version) == 0 { continue } allowed, denied := triageOperations(resource.Operations) handleResourceOperations(bktPolicy, allowed, eacl.ActionAllow, resource.Name()) handleResourceOperations(bktPolicy, denied, eacl.ActionDeny, resource.Name()) } return bktPolicy } func handleResourceOperations(bktPolicy *bucketPolicy, list []*astOperation, eaclAction eacl.Action, resourceName string) { userOpsMap := make(map[string][]eacl.Operation) for _, op := range list { if !op.IsGroupGrantee() { for _, user := range op.Users { userOps := userOpsMap[user] userOps = append(userOps, op.Op) userOpsMap[user] = userOps } } else { userOps := userOpsMap[allUsersGroup] userOps = append(userOps, op.Op) userOpsMap[allUsersGroup] = userOps } } for user, userOps := range userOpsMap { var actions []string LOOP: for action, ops := range actionToOpMap { for _, op := range ops { if !contains(userOps, op) { break LOOP } } actions = append(actions, action) } if len(actions) != 0 { state := statement{ Effect: actionToEffect(eaclAction), Principal: principal{CanonicalUser: user}, Action: actions, Resource: []string{arnAwsPrefix + resourceName}, } if user == allUsersGroup { state.Principal = principal{AWS: allUsersWildcard} } bktPolicy.Statement = append(bktPolicy.Statement, state) } } } func triageOperations(operations []*astOperation) ([]*astOperation, []*astOperation) { var allowed, denied []*astOperation for _, op := range operations { if op.Action == eacl.ActionAllow { allowed = append(allowed, op) } else { denied = append(denied, op) } } return allowed, denied } func addTo(list []*astOperation, userID string, op eacl.Operation, groupGrantee bool, action eacl.Action) []*astOperation { var found *astOperation for _, astop := range list { if astop.Op == op && astop.IsGroupGrantee() == groupGrantee { found = astop } } if found != nil { if !groupGrantee { found.Users = append(found.Users, userID) } } else { astoperation := &astOperation{ Op: op, Action: action, } if !groupGrantee { astoperation.Users = append(astoperation.Users, userID) } list = append(list, astoperation) } return list } func aclToAst(acl *AccessControlPolicy, resInfo *resourceInfo) (*ast, error) { res := &ast{} resource := &astResource{resourceInfo: *resInfo} ops := readOps if resInfo.IsBucket() { ops = append(ops, writeOps...) } for _, op := range ops { operation := &astOperation{ Users: []string{acl.Owner.ID}, Op: op, Action: eacl.ActionAllow, } resource.Operations = append(resource.Operations, operation) } for _, grant := range acl.AccessControlList { if grant.Grantee.Type == acpAmazonCustomerByEmail || (grant.Grantee.Type == acpGroup && grant.Grantee.URI != allUsersGroup) { return nil, stderrors.New("unsupported grantee type") } var groupGrantee bool if grant.Grantee.Type == acpGroup { groupGrantee = true } else if grant.Grantee.ID == acl.Owner.ID { continue } for _, action := range getActions(grant.Permission, resInfo.IsBucket()) { for _, op := range actionToOpMap[action] { resource.Operations = addTo(resource.Operations, grant.Grantee.ID, op, groupGrantee, eacl.ActionAllow) } } } res.Resources = []*astResource{resource} return res, nil } func aclToPolicy(acl *AccessControlPolicy, resInfo *resourceInfo) (*bucketPolicy, error) { if resInfo.Bucket == "" { return nil, fmt.Errorf("resource bucket must not be empty") } results := []statement{ getAllowStatement(resInfo, acl.Owner.ID, aclFullControl), } for _, grant := range acl.AccessControlList { if grant.Grantee.Type == acpAmazonCustomerByEmail || (grant.Grantee.Type == acpGroup && grant.Grantee.URI != allUsersGroup) { return nil, stderrors.New("unsupported grantee type") } user := grant.Grantee.ID if grant.Grantee.Type == acpGroup { user = allUsersWildcard } else if user == acl.Owner.ID { continue } results = append(results, getAllowStatement(resInfo, user, grant.Permission)) } return &bucketPolicy{ Statement: results, Bucket: resInfo.Bucket, }, nil } func getAllowStatement(resInfo *resourceInfo, id string, permission AWSACL) statement { state := statement{ Effect: "Allow", Principal: principal{ CanonicalUser: id, }, Action: getActions(permission, resInfo.IsBucket()), Resource: []string{arnAwsPrefix + resInfo.Name()}, } if id == allUsersWildcard { state.Principal = principal{AWS: allUsersWildcard} } return state } func getActions(permission AWSACL, isBucket bool) []string { var res []string switch permission { case aclRead: if isBucket { res = []string{s3ListBucket, s3ListBucketVersions, s3ListBucketMultipartUploads} } else { res = []string{s3GetObject, s3GetObjectVersion} } case aclWrite: if isBucket { res = []string{s3PutObject, s3DeleteObject} } case aclFullControl: if isBucket { res = []string{s3ListBucket, s3ListBucketVersions, s3ListBucketMultipartUploads, s3PutObject, s3DeleteObject} } else { res = []string{s3GetObject, s3GetObjectVersion} } } return res } func effectToAction(effect string) eacl.Action { switch effect { case "Allow": return eacl.ActionAllow case "Deny": return eacl.ActionDeny } return eacl.ActionUnknown } func actionToEffect(action eacl.Action) string { switch action { case eacl.ActionAllow: return "Allow" case eacl.ActionDeny: return "Deny" default: return "" } } func permissionToOperations(permission AWSACL) []eacl.Operation { switch permission { case aclFullControl: return fullOps case aclRead: return readOps case aclWrite: return writeOps } return nil } func isWriteOperation(op eacl.Operation) bool { return op == eacl.OperationDelete || op == eacl.OperationPut } func (h *handler) encodeObjectACL(bucketACL *layer.BucketACL, objectName string) *AccessControlPolicy { res := &AccessControlPolicy{ Owner: Owner{ ID: bucketACL.Info.Owner.String(), DisplayName: bucketACL.Info.Owner.String(), }, } m := make(map[string][]eacl.Operation) for _, record := range bucketACL.EACL.Records() { if len(record.Targets()) != 1 { h.log.Warn("some acl not fully mapped") continue } if objectName != "" { var found bool for _, filter := range record.Filters() { if filter.Matcher() == eacl.MatchStringEqual && filter.Key() == object.AttributeFileName && filter.Value() == objectName { found = true } } if !found { continue } } target := record.Targets()[0] if target.Role() == eacl.RoleOthers { if record.Action() == eacl.ActionAllow { list := append(m[allUsersGroup], record.Operation()) m[allUsersGroup] = list } continue } for _, key := range target.BinaryKeys() { id := hex.EncodeToString(key) list := append(m[id], record.Operation()) m[id] = list } } for key, val := range m { permission := aclFullControl read, write := true, true for op := eacl.OperationGet; op <= eacl.OperationRangeHash; op++ { if !contains(val, op) { if isWriteOperation(op) { write = false } else { read = false } } } if !read && !write { h.log.Warn("some acl not fully mapped") continue } if !read { permission = aclWrite } else if !write { permission = aclRead } var grantee *Grantee if key == allUsersGroup { grantee = NewGrantee(acpGroup) grantee.URI = allUsersGroup } else { grantee = NewGrantee(acpCanonicalUser) grantee.ID = key } grant := &Grant{ Grantee: grantee, Permission: permission, } res.AccessControlList = append(res.AccessControlList, grant) } return res } func (h *handler) encodeBucketACL(bucketACL *layer.BucketACL) *AccessControlPolicy { return h.encodeObjectACL(bucketACL, "") } func contains(list []eacl.Operation, op eacl.Operation) bool { for _, operation := range list { if operation == op { return true } } return false } type getRecordFunc func(op eacl.Operation) *eacl.Record func bucketACLToTable(acp *AccessControlPolicy, resInfo *resourceInfo) (*eacl.Table, error) { if !resInfo.IsBucket() { return nil, fmt.Errorf("allowed only bucket acl") } var found bool table := eacl.NewTable() ownerKey, err := keys.NewPublicKeyFromString(acp.Owner.ID) if err != nil { return nil, fmt.Errorf("public key from string: %w", err) } for _, grant := range acp.AccessControlList { if !isValidGrant(grant) { return nil, stderrors.New("unsupported grantee") } if grant.Grantee.ID == acp.Owner.ID { found = true } getRecord, err := getRecordFunction(grant.Grantee) if err != nil { return nil, fmt.Errorf("record func from grantee: %w", err) } for _, op := range permissionToOperations(grant.Permission) { table.AddRecord(getRecord(op)) } } if !found { for _, op := range fullOps { table.AddRecord(getAllowRecord(op, ownerKey)) } } for _, op := range fullOps { table.AddRecord(getOthersRecord(op, eacl.ActionDeny)) } return table, nil } func getRecordFunction(grantee *Grantee) (getRecordFunc, error) { switch grantee.Type { case acpAmazonCustomerByEmail: case acpCanonicalUser: pk, err := keys.NewPublicKeyFromString(grantee.ID) if err != nil { return nil, fmt.Errorf("couldn't parse canonical ID %s: %w", grantee.ID, err) } return func(op eacl.Operation) *eacl.Record { return getAllowRecord(op, pk) }, nil case acpGroup: return func(op eacl.Operation) *eacl.Record { return getOthersRecord(op, eacl.ActionAllow) }, nil } return nil, fmt.Errorf("unknown type: %s", grantee.Type) } func isValidGrant(grant *Grant) bool { return (grant.Permission == aclFullControl || grant.Permission == aclRead || grant.Permission == aclWrite) && (grant.Grantee.Type == acpCanonicalUser || (grant.Grantee.Type == acpGroup && grant.Grantee.URI == allUsersGroup)) } func getAllowRecord(op eacl.Operation, pk *keys.PublicKey) *eacl.Record { record := eacl.NewRecord() record.SetOperation(op) record.SetAction(eacl.ActionAllow) // Unknown role is used, because it is ignored when keys are set eacl.AddFormedTarget(record, eacl.RoleUnknown, (ecdsa.PublicKey)(*pk)) return record } func getOthersRecord(op eacl.Operation, action eacl.Action) *eacl.Record { record := eacl.NewRecord() record.SetOperation(op) record.SetAction(action) eacl.AddFormedTarget(record, eacl.RoleOthers) return record }