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minio/cmd/bucket-object-lock.go

346 lines
13 KiB

/*
* MinIO Cloud Storage, (C) 2019-2020 MinIO, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cmd
import (
"context"
"math"
"net/http"
xhttp "github.com/minio/minio/cmd/http"
"github.com/minio/minio/cmd/logger"
"github.com/minio/minio/pkg/auth"
objectlock "github.com/minio/minio/pkg/bucket/object/lock"
"github.com/minio/minio/pkg/bucket/policy"
"github.com/minio/minio/pkg/bucket/replication"
)
// BucketObjectLockSys - map of bucket and retention configuration.
type BucketObjectLockSys struct{}
// Get - Get retention configuration.
func (sys *BucketObjectLockSys) Get(bucketName string) (r objectlock.Retention, err error) {
if globalIsGateway {
objAPI := newObjectLayerFn()
if objAPI == nil {
return r, errServerNotInitialized
}
return r, nil
}
config, err := globalBucketMetadataSys.GetObjectLockConfig(bucketName)
if err != nil {
if _, ok := err.(BucketObjectLockConfigNotFound); ok {
return r, nil
}
return r, err
}
return config.ToRetention(), nil
}
// enforceRetentionForDeletion checks if it is appropriate to remove an
// object according to locking configuration when this is lifecycle/ bucket quota asking.
func enforceRetentionForDeletion(ctx context.Context, objInfo ObjectInfo) (locked bool) {
lhold := objectlock.GetObjectLegalHoldMeta(objInfo.UserDefined)
if lhold.Status.Valid() && lhold.Status == objectlock.LegalHoldOn {
return true
}
ret := objectlock.GetObjectRetentionMeta(objInfo.UserDefined)
if ret.Mode.Valid() && (ret.Mode == objectlock.RetCompliance || ret.Mode == objectlock.RetGovernance) {
t, err := objectlock.UTCNowNTP()
if err != nil {
logger.LogIf(ctx, err)
return true
}
if ret.RetainUntilDate.After(t) {
return true
}
}
return false
}
// enforceRetentionBypassForDelete enforces whether an existing object under governance can be deleted
// with governance bypass headers set in the request.
// Objects under site wide WORM can never be overwritten.
// For objects in "Governance" mode, overwrite is allowed if a) object retention date is past OR
// governance bypass headers are set and user has governance bypass permissions.
// Objects in "Compliance" mode can be overwritten only if retention date is past.
func enforceRetentionBypassForDelete(ctx context.Context, r *http.Request, bucket string, object ObjectToDelete, oi ObjectInfo, gerr error) APIErrorCode {
opts, err := getOpts(ctx, r, bucket, object.ObjectName)
if err != nil {
return toAPIErrorCode(ctx, err)
}
opts.VersionID = object.VersionID
if gerr != nil { // error from GetObjectInfo
switch err.(type) {
case MethodNotAllowed: // This happens usually for a delete marker
if oi.DeleteMarker {
// Delete marker should be present and valid.
return ErrNone
}
}
return toAPIErrorCode(ctx, err)
}
lhold := objectlock.GetObjectLegalHoldMeta(oi.UserDefined)
if lhold.Status.Valid() && lhold.Status == objectlock.LegalHoldOn {
return ErrObjectLocked
}
ret := objectlock.GetObjectRetentionMeta(oi.UserDefined)
if ret.Mode.Valid() {
switch ret.Mode {
case objectlock.RetCompliance:
// In compliance mode, a protected object version can't be overwritten
// or deleted by any user, including the root user in your AWS account.
// When an object is locked in compliance mode, its retention mode can't
// be changed, and its retention period can't be shortened. Compliance mode
// ensures that an object version can't be overwritten or deleted for the
// duration of the retention period.
t, err := objectlock.UTCNowNTP()
if err != nil {
logger.LogIf(ctx, err)
return ErrObjectLocked
}
if !ret.RetainUntilDate.Before(t) {
return ErrObjectLocked
}
return ErrNone
case objectlock.RetGovernance:
// In governance mode, users can't overwrite or delete an object
// version or alter its lock settings unless they have special
// permissions. With governance mode, you protect objects against
// being deleted by most users, but you can still grant some users
// permission to alter the retention settings or delete the object
// if necessary. You can also use governance mode to test retention-period
// settings before creating a compliance-mode retention period.
// To override or remove governance-mode retention settings, a
// user must have the s3:BypassGovernanceRetention permission
// and must explicitly include x-amz-bypass-governance-retention:true
// as a request header with any request that requires overriding
// governance mode.
//
byPassSet := objectlock.IsObjectLockGovernanceBypassSet(r.Header)
if !byPassSet {
t, err := objectlock.UTCNowNTP()
if err != nil {
logger.LogIf(ctx, err)
return ErrObjectLocked
}
if !ret.RetainUntilDate.Before(t) {
return ErrObjectLocked
}
return ErrNone
}
// https://docs.aws.amazon.com/AmazonS3/latest/dev/object-lock-overview.html#object-lock-retention-modes
// If you try to delete objects protected by governance mode and have s3:BypassGovernanceRetention
// or s3:GetBucketObjectLockConfiguration permissions, the operation will succeed.
govBypassPerms1 := checkRequestAuthType(ctx, r, policy.BypassGovernanceRetentionAction, bucket, object.ObjectName)
govBypassPerms2 := checkRequestAuthType(ctx, r, policy.GetBucketObjectLockConfigurationAction, bucket, object.ObjectName)
if govBypassPerms1 != ErrNone && govBypassPerms2 != ErrNone {
return ErrAccessDenied
}
}
}
return ErrNone
}
// enforceRetentionBypassForPut enforces whether an existing object under governance can be overwritten
// with governance bypass headers set in the request.
// Objects under site wide WORM cannot be overwritten.
// For objects in "Governance" mode, overwrite is allowed if a) object retention date is past OR
// governance bypass headers are set and user has governance bypass permissions.
// Objects in compliance mode can be overwritten only if retention date is being extended. No mode change is permitted.
func enforceRetentionBypassForPut(ctx context.Context, r *http.Request, bucket, object string, getObjectInfoFn GetObjectInfoFn, objRetention *objectlock.ObjectRetention, cred auth.Credentials, owner bool, claims map[string]interface{}) (ObjectInfo, APIErrorCode) {
byPassSet := objectlock.IsObjectLockGovernanceBypassSet(r.Header)
opts, err := getOpts(ctx, r, bucket, object)
if err != nil {
return ObjectInfo{}, toAPIErrorCode(ctx, err)
}
oi, err := getObjectInfoFn(ctx, bucket, object, opts)
if err != nil {
return oi, toAPIErrorCode(ctx, err)
}
t, err := objectlock.UTCNowNTP()
if err != nil {
logger.LogIf(ctx, err)
return oi, ErrObjectLocked
}
// Pass in relative days from current time, to additionally to verify "object-lock-remaining-retention-days" policy if any.
days := int(math.Ceil(math.Abs(objRetention.RetainUntilDate.Sub(t).Hours()) / 24))
ret := objectlock.GetObjectRetentionMeta(oi.UserDefined)
if ret.Mode.Valid() {
// Retention has expired you may change whatever you like.
if ret.RetainUntilDate.Before(t) {
perm := isPutRetentionAllowed(bucket, object,
days, objRetention.RetainUntilDate.Time,
objRetention.Mode, byPassSet, r, cred,
owner, claims)
return oi, perm
}
switch ret.Mode {
case objectlock.RetGovernance:
govPerm := isPutRetentionAllowed(bucket, object, days,
objRetention.RetainUntilDate.Time, objRetention.Mode,
byPassSet, r, cred, owner, claims)
// Governance mode retention period cannot be shortened, if x-amz-bypass-governance is not set.
if !byPassSet {
if objRetention.Mode != objectlock.RetGovernance || objRetention.RetainUntilDate.Before((ret.RetainUntilDate.Time)) {
return oi, ErrObjectLocked
}
}
return oi, govPerm
case objectlock.RetCompliance:
// Compliance retention mode cannot be changed or shortened.
// https://docs.aws.amazon.com/AmazonS3/latest/dev/object-lock-overview.html#object-lock-retention-modes
if objRetention.Mode != objectlock.RetCompliance || objRetention.RetainUntilDate.Before((ret.RetainUntilDate.Time)) {
return oi, ErrObjectLocked
}
compliancePerm := isPutRetentionAllowed(bucket, object,
days, objRetention.RetainUntilDate.Time, objRetention.Mode,
false, r, cred, owner, claims)
return oi, compliancePerm
}
return oi, ErrNone
} // No pre-existing retention metadata present.
perm := isPutRetentionAllowed(bucket, object,
days, objRetention.RetainUntilDate.Time,
objRetention.Mode, byPassSet, r, cred, owner, claims)
return oi, perm
}
// checkPutObjectLockAllowed enforces object retention policy and legal hold policy
// for requests with WORM headers
// See https://docs.aws.amazon.com/AmazonS3/latest/dev/object-lock-managing.html for the spec.
// For non-existing objects with object retention headers set, this method returns ErrNone if bucket has
// locking enabled and user has requisite permissions (s3:PutObjectRetention)
// If object exists on object store and site wide WORM enabled - this method
// returns an error. For objects in "Governance" mode, overwrite is allowed if the retention date has expired.
// For objects in "Compliance" mode, retention date cannot be shortened, and mode cannot be altered.
// For objects with legal hold header set, the s3:PutObjectLegalHold permission is expected to be set
// Both legal hold and retention can be applied independently on an object
func checkPutObjectLockAllowed(ctx context.Context, rq *http.Request, bucket, object string, getObjectInfoFn GetObjectInfoFn, retentionPermErr, legalHoldPermErr APIErrorCode) (objectlock.RetMode, objectlock.RetentionDate, objectlock.ObjectLegalHold, APIErrorCode) {
var mode objectlock.RetMode
var retainDate objectlock.RetentionDate
var legalHold objectlock.ObjectLegalHold
retentionRequested := objectlock.IsObjectLockRetentionRequested(rq.Header)
legalHoldRequested := objectlock.IsObjectLockLegalHoldRequested(rq.Header)
retentionCfg, err := globalBucketObjectLockSys.Get(bucket)
if err != nil {
return mode, retainDate, legalHold, ErrInvalidBucketObjectLockConfiguration
}
if !retentionCfg.LockEnabled {
if legalHoldRequested || retentionRequested {
return mode, retainDate, legalHold, ErrInvalidBucketObjectLockConfiguration
}
// If this not a WORM enabled bucket, we should return right here.
return mode, retainDate, legalHold, ErrNone
}
opts, err := getOpts(ctx, rq, bucket, object)
if err != nil {
return mode, retainDate, legalHold, toAPIErrorCode(ctx, err)
}
replica := rq.Header.Get(xhttp.AmzBucketReplicationStatus) == replication.Replica.String()
if opts.VersionID != "" && !replica {
if objInfo, err := getObjectInfoFn(ctx, bucket, object, opts); err == nil {
r := objectlock.GetObjectRetentionMeta(objInfo.UserDefined)
t, err := objectlock.UTCNowNTP()
if err != nil {
logger.LogIf(ctx, err)
return mode, retainDate, legalHold, ErrObjectLocked
}
if r.Mode == objectlock.RetCompliance && r.RetainUntilDate.After(t) {
return mode, retainDate, legalHold, ErrObjectLocked
}
mode = r.Mode
retainDate = r.RetainUntilDate
legalHold = objectlock.GetObjectLegalHoldMeta(objInfo.UserDefined)
// Disallow overwriting an object on legal hold
if legalHold.Status == objectlock.LegalHoldOn {
return mode, retainDate, legalHold, ErrObjectLocked
}
}
}
if legalHoldRequested {
var lerr error
if legalHold, lerr = objectlock.ParseObjectLockLegalHoldHeaders(rq.Header); lerr != nil {
return mode, retainDate, legalHold, toAPIErrorCode(ctx, err)
}
}
if retentionRequested {
legalHold, err := objectlock.ParseObjectLockLegalHoldHeaders(rq.Header)
if err != nil {
return mode, retainDate, legalHold, toAPIErrorCode(ctx, err)
}
rMode, rDate, err := objectlock.ParseObjectLockRetentionHeaders(rq.Header)
if err != nil {
return mode, retainDate, legalHold, toAPIErrorCode(ctx, err)
}
if retentionPermErr != ErrNone {
return mode, retainDate, legalHold, retentionPermErr
}
return rMode, rDate, legalHold, ErrNone
}
if replica { // replica inherits retention metadata only from source
return "", objectlock.RetentionDate{}, legalHold, ErrNone
}
if !retentionRequested && retentionCfg.Validity > 0 {
if retentionPermErr != ErrNone {
return mode, retainDate, legalHold, retentionPermErr
}
t, err := objectlock.UTCNowNTP()
if err != nil {
logger.LogIf(ctx, err)
return mode, retainDate, legalHold, ErrObjectLocked
}
if !legalHoldRequested && retentionCfg.LockEnabled {
// inherit retention from bucket configuration
return retentionCfg.Mode, objectlock.RetentionDate{Time: t.Add(retentionCfg.Validity)}, legalHold, ErrNone
}
return "", objectlock.RetentionDate{}, legalHold, ErrNone
}
return mode, retainDate, legalHold, ErrNone
}
// NewBucketObjectLockSys returns initialized BucketObjectLockSys
func NewBucketObjectLockSys() *BucketObjectLockSys {
return &BucketObjectLockSys{}
}