/* * MinIO Cloud Storage, (C) 2017, 2018, 2019 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 s3 import ( "context" "encoding/json" "io" "math/rand" "net/http" "net/url" "strings" "time" "github.com/minio/cli" miniogo "github.com/minio/minio-go/v6" "github.com/minio/minio-go/v6/pkg/credentials" minio "github.com/minio/minio/cmd" "github.com/minio/minio-go/v6/pkg/encrypt" "github.com/minio/minio-go/v6/pkg/s3utils" "github.com/minio/minio/cmd/logger" "github.com/minio/minio/pkg/auth" "github.com/minio/minio/pkg/policy" ) const ( s3Backend = "s3" ) func init() { const s3GatewayTemplate = `NAME: {{.HelpName}} - {{.Usage}} USAGE: {{.HelpName}} {{if .VisibleFlags}}[FLAGS]{{end}} [ENDPOINT] {{if .VisibleFlags}} FLAGS: {{range .VisibleFlags}}{{.}} {{end}}{{end}} ENDPOINT: S3 server endpoint. Default ENDPOINT is https://s3.amazonaws.com ENVIRONMENT VARIABLES: ACCESS: MINIO_ACCESS_KEY: Username or access key of S3 storage. MINIO_SECRET_KEY: Password or secret key of S3 storage. BROWSER: MINIO_BROWSER: To disable web browser access, set this value to "off". DOMAIN: MINIO_DOMAIN: To enable virtual-host-style requests, set this value to MinIO host domain name. CACHE: MINIO_CACHE_DRIVES: List of mounted drives or directories delimited by ";". MINIO_CACHE_EXCLUDE: List of cache exclusion patterns delimited by ";". MINIO_CACHE_EXPIRY: Cache expiry duration in days. MINIO_CACHE_MAXUSE: Maximum permitted usage of the cache in percentage (0-100). LOGGER: MINIO_LOGGER_HTTP_ENDPOINT: HTTP endpoint URL to log all incoming requests. EXAMPLES: 1. Start minio gateway server for AWS S3 backend. {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}accesskey {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}secretkey {{.Prompt}} {{.HelpName}} 2. Start minio gateway server for S3 backend on custom endpoint. {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}Q3AM3UQ867SPQQA43P2F {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}zuf+tfteSlswRu7BJ86wekitnifILbZam1KYY3TG {{.Prompt}} {{.HelpName}} https://play.min.io:9000 3. Start minio gateway server for AWS S3 backend logging all requests to http endpoint. {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}Q3AM3UQ867SPQQA43P2F {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}zuf+tfteSlswRu7BJ86wekitnifILbZam1KYY3TG {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}"http://localhost:8000/" {{.Prompt}} {{.HelpName}} https://play.min.io:9000 4. Start minio gateway server for AWS S3 backend with edge caching enabled. {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}accesskey {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}secretkey {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}"/mnt/drive1;/mnt/drive2;/mnt/drive3;/mnt/drive4" {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}"bucket1/*;*.png" {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}40 {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}80 {{.Prompt}} {{.HelpName}} 4. Start minio gateway server for AWS S3 backend using AWS environment variables. NOTE: The access and secret key in this case will authenticate with MinIO instead of AWS and AWS envs will be used to authenticate to AWS S3. {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}aws_access_key {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}aws_secret_key {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}accesskey {{.Prompt}} {{.EnvVarSetCommand}}(.*){{.AssignmentOperator}}secretkey {{.Prompt}} {{.HelpName}} ` minio.RegisterGatewayCommand(cli.Command{ Name: s3Backend, Usage: "Amazon Simple Storage Service (S3)", Action: s3GatewayMain, CustomHelpTemplate: s3GatewayTemplate, HideHelpCommand: true, }) } // Handler for 'minio gateway s3' command line. func s3GatewayMain(ctx *cli.Context) { args := ctx.Args() if !ctx.Args().Present() { args = cli.Args{"https://s3.amazonaws.com"} } // Validate gateway arguments. logger.FatalIf(minio.ValidateGatewayArguments(ctx.GlobalString("address"), args.First()), "Invalid argument") // Start the gateway.. minio.StartGateway(ctx, &S3{args.First()}) } // S3 implements Gateway. type S3 struct { host string } // Name implements Gateway interface. func (g *S3) Name() string { return s3Backend } const letterBytes = "abcdefghijklmnopqrstuvwxyz01234569" const ( letterIdxBits = 6 // 6 bits to represent a letter index letterIdxMask = 1<= 0; { if remain == 0 { cache, remain = src.Int63(), letterIdxMax } if idx := int(cache & letterIdxMask); idx < len(letterBytes) { b[i] = letterBytes[idx] i-- } cache >>= letterIdxBits remain-- } return prefix + string(b[0:30-len(prefix)]) } // Chains all credential types, in the following order: // - AWS env vars (i.e. AWS_ACCESS_KEY_ID) // - AWS creds file (i.e. AWS_SHARED_CREDENTIALS_FILE or ~/.aws/credentials) // - Static credentials provided by user (i.e. MINIO_ACCESS_KEY) var defaultProviders = []credentials.Provider{ &credentials.EnvAWS{}, &credentials.FileAWSCredentials{}, &credentials.EnvMinio{}, } // Chains all credential types, in the following order: // - AWS env vars (i.e. AWS_ACCESS_KEY_ID) // - AWS creds file (i.e. AWS_SHARED_CREDENTIALS_FILE or ~/.aws/credentials) // - IAM profile based credentials. (performs an HTTP // call to a pre-defined endpoint, only valid inside // configured ec2 instances) var defaultAWSCredProviders = []credentials.Provider{ &credentials.EnvAWS{}, &credentials.FileAWSCredentials{}, &credentials.IAM{ Client: &http.Client{ Transport: minio.NewCustomHTTPTransport(), }, }, &credentials.EnvMinio{}, } // newS3 - Initializes a new client by auto probing S3 server signature. func newS3(urlStr string) (*miniogo.Core, error) { if urlStr == "" { urlStr = "https://s3.amazonaws.com" } u, err := url.Parse(urlStr) if err != nil { return nil, err } // Override default params if the host is provided endpoint, secure, err := minio.ParseGatewayEndpoint(urlStr) if err != nil { return nil, err } var creds *credentials.Credentials if s3utils.IsAmazonEndpoint(*u) { // If we see an Amazon S3 endpoint, then we use more ways to fetch backend credentials. // Specifically IAM style rotating credentials are only supported with AWS S3 endpoint. creds = credentials.NewChainCredentials(defaultAWSCredProviders) } else { creds = credentials.NewChainCredentials(defaultProviders) } options := miniogo.Options{ Creds: creds, Secure: secure, Region: s3utils.GetRegionFromURL(*u), BucketLookup: miniogo.BucketLookupAuto, } clnt, err := miniogo.NewWithOptions(endpoint, &options) if err != nil { return nil, err } // Set custom transport clnt.SetCustomTransport(minio.NewCustomHTTPTransport()) probeBucketName := randString(60, rand.NewSource(time.Now().UnixNano()), "probe-bucket-sign-") // Set maximum retry operations. miniogo.MaxRetry = 1 // Check if the provided keys are valid. if _, err = clnt.BucketExists(probeBucketName); err != nil { if miniogo.ToErrorResponse(err).Code != "AccessDenied" { return nil, err } } return &miniogo.Core{Client: clnt}, nil } // NewGatewayLayer returns s3 ObjectLayer. func (g *S3) NewGatewayLayer(creds auth.Credentials) (minio.ObjectLayer, error) { // creds are ignored here, since S3 gateway implements chaining // all credentials. clnt, err := newS3(g.host) if err != nil { return nil, err } s := s3Objects{ Client: clnt, } // Enables single encyption of KMS is configured. if minio.GlobalKMS != nil { encS := s3EncObjects{s} // Start stale enc multipart uploads cleanup routine. go encS.cleanupStaleEncMultipartUploads(context.Background(), minio.GlobalMultipartCleanupInterval, minio.GlobalMultipartExpiry, minio.GlobalServiceDoneCh) return &encS, nil } return &s, nil } // Production - s3 gateway is production ready. func (g *S3) Production() bool { return true } // s3Objects implements gateway for MinIO and S3 compatible object storage servers. type s3Objects struct { minio.GatewayUnsupported Client *miniogo.Core } // Shutdown saves any gateway metadata to disk // if necessary and reload upon next restart. func (l *s3Objects) Shutdown(ctx context.Context) error { return nil } // StorageInfo is not relevant to S3 backend. func (l *s3Objects) StorageInfo(ctx context.Context) (si minio.StorageInfo) { return si } // MakeBucket creates a new container on S3 backend. func (l *s3Objects) MakeBucketWithLocation(ctx context.Context, bucket, location string) error { // Verify if bucket name is valid. // We are using a separate helper function here to validate bucket // names instead of IsValidBucketName() because there is a possibility // that certains users might have buckets which are non-DNS compliant // in us-east-1 and we might severely restrict them by not allowing // access to these buckets. // Ref - http://docs.aws.amazon.com/AmazonS3/latest/dev/BucketRestrictions.html if s3utils.CheckValidBucketName(bucket) != nil { return minio.BucketNameInvalid{Bucket: bucket} } err := l.Client.MakeBucket(bucket, location) if err != nil { return minio.ErrorRespToObjectError(err, bucket) } return err } // GetBucketInfo gets bucket metadata.. func (l *s3Objects) GetBucketInfo(ctx context.Context, bucket string) (bi minio.BucketInfo, e error) { buckets, err := l.Client.ListBuckets() if err != nil { // Listbuckets may be disallowed, proceed to check if // bucket indeed exists, if yes return success. var ok bool if ok, err = l.Client.BucketExists(bucket); err != nil { return bi, minio.ErrorRespToObjectError(err, bucket) } if !ok { return bi, minio.BucketNotFound{Bucket: bucket} } return minio.BucketInfo{ Name: bi.Name, Created: time.Now().UTC(), }, nil } for _, bi := range buckets { if bi.Name != bucket { continue } return minio.BucketInfo{ Name: bi.Name, Created: bi.CreationDate, }, nil } return bi, minio.BucketNotFound{Bucket: bucket} } // ListBuckets lists all S3 buckets func (l *s3Objects) ListBuckets(ctx context.Context) ([]minio.BucketInfo, error) { buckets, err := l.Client.ListBuckets() if err != nil { return nil, minio.ErrorRespToObjectError(err) } b := make([]minio.BucketInfo, len(buckets)) for i, bi := range buckets { b[i] = minio.BucketInfo{ Name: bi.Name, Created: bi.CreationDate, } } return b, err } // DeleteBucket deletes a bucket on S3 func (l *s3Objects) DeleteBucket(ctx context.Context, bucket string) error { err := l.Client.RemoveBucket(bucket) if err != nil { return minio.ErrorRespToObjectError(err, bucket) } return nil } // ListObjects lists all blobs in S3 bucket filtered by prefix func (l *s3Objects) ListObjects(ctx context.Context, bucket string, prefix string, marker string, delimiter string, maxKeys int) (loi minio.ListObjectsInfo, e error) { result, err := l.Client.ListObjects(bucket, prefix, marker, delimiter, maxKeys) if err != nil { return loi, minio.ErrorRespToObjectError(err, bucket) } return minio.FromMinioClientListBucketResult(bucket, result), nil } // ListObjectsV2 lists all blobs in S3 bucket filtered by prefix func (l *s3Objects) ListObjectsV2(ctx context.Context, bucket, prefix, continuationToken, delimiter string, maxKeys int, fetchOwner bool, startAfter string) (loi minio.ListObjectsV2Info, e error) { result, err := l.Client.ListObjectsV2(bucket, prefix, continuationToken, fetchOwner, delimiter, maxKeys, startAfter) if err != nil { return loi, minio.ErrorRespToObjectError(err, bucket) } return minio.FromMinioClientListBucketV2Result(bucket, result), nil } // GetObjectNInfo - returns object info and locked object ReadCloser func (l *s3Objects) GetObjectNInfo(ctx context.Context, bucket, object string, rs *minio.HTTPRangeSpec, h http.Header, lockType minio.LockType, opts minio.ObjectOptions) (gr *minio.GetObjectReader, err error) { var objInfo minio.ObjectInfo objInfo, err = l.GetObjectInfo(ctx, bucket, object, opts) if err != nil { return nil, minio.ErrorRespToObjectError(err, bucket, object) } var startOffset, length int64 startOffset, length, err = rs.GetOffsetLength(objInfo.Size) if err != nil { return nil, minio.ErrorRespToObjectError(err, bucket, object) } pr, pw := io.Pipe() go func() { err := l.GetObject(ctx, bucket, object, startOffset, length, pw, objInfo.ETag, opts) pw.CloseWithError(err) }() // Setup cleanup function to cause the above go-routine to // exit in case of partial read pipeCloser := func() { pr.Close() } return minio.NewGetObjectReaderFromReader(pr, objInfo, opts.CheckCopyPrecondFn, pipeCloser) } // GetObject reads an object from S3. Supports additional // parameters like offset and length which are synonymous with // HTTP Range requests. // // startOffset indicates the starting read location of the object. // length indicates the total length of the object. func (l *s3Objects) GetObject(ctx context.Context, bucket string, key string, startOffset int64, length int64, writer io.Writer, etag string, o minio.ObjectOptions) error { if length < 0 && length != -1 { return minio.ErrorRespToObjectError(minio.InvalidRange{}, bucket, key) } opts := miniogo.GetObjectOptions{} opts.ServerSideEncryption = o.ServerSideEncryption if startOffset >= 0 && length >= 0 { if err := opts.SetRange(startOffset, startOffset+length-1); err != nil { return minio.ErrorRespToObjectError(err, bucket, key) } } object, _, err := l.Client.GetObject(bucket, key, opts) if err != nil { return minio.ErrorRespToObjectError(err, bucket, key) } defer object.Close() if _, err := io.Copy(writer, object); err != nil { return minio.ErrorRespToObjectError(err, bucket, key) } return nil } // GetObjectInfo reads object info and replies back ObjectInfo func (l *s3Objects) GetObjectInfo(ctx context.Context, bucket string, object string, opts minio.ObjectOptions) (objInfo minio.ObjectInfo, err error) { oi, err := l.Client.StatObject(bucket, object, miniogo.StatObjectOptions{ GetObjectOptions: miniogo.GetObjectOptions{ ServerSideEncryption: opts.ServerSideEncryption, }, }) if err != nil { return minio.ObjectInfo{}, minio.ErrorRespToObjectError(err, bucket, object) } return minio.FromMinioClientObjectInfo(bucket, oi), nil } // PutObject creates a new object with the incoming data, func (l *s3Objects) PutObject(ctx context.Context, bucket string, object string, r *minio.PutObjReader, opts minio.ObjectOptions) (objInfo minio.ObjectInfo, err error) { data := r.Reader oi, err := l.Client.PutObject(bucket, object, data, data.Size(), data.MD5Base64String(), data.SHA256HexString(), minio.ToMinioClientMetadata(opts.UserDefined), opts.ServerSideEncryption) if err != nil { return objInfo, minio.ErrorRespToObjectError(err, bucket, object) } // On success, populate the key & metadata so they are present in the notification oi.Key = object oi.Metadata = minio.ToMinioClientObjectInfoMetadata(opts.UserDefined) return minio.FromMinioClientObjectInfo(bucket, oi), nil } // CopyObject copies an object from source bucket to a destination bucket. func (l *s3Objects) CopyObject(ctx context.Context, srcBucket string, srcObject string, dstBucket string, dstObject string, srcInfo minio.ObjectInfo, srcOpts, dstOpts minio.ObjectOptions) (objInfo minio.ObjectInfo, err error) { if srcOpts.CheckCopyPrecondFn != nil && srcOpts.CheckCopyPrecondFn(srcInfo, "") { return minio.ObjectInfo{}, minio.PreConditionFailed{} } // Set this header such that following CopyObject() always sets the right metadata on the destination. // metadata input is already a trickled down value from interpreting x-amz-metadata-directive at // handler layer. So what we have right now is supposed to be applied on the destination object anyways. // So preserve it by adding "REPLACE" directive to save all the metadata set by CopyObject API. srcInfo.UserDefined["x-amz-metadata-directive"] = "REPLACE" srcInfo.UserDefined["x-amz-copy-source-if-match"] = srcInfo.ETag header := make(http.Header) if srcOpts.ServerSideEncryption != nil { encrypt.SSECopy(srcOpts.ServerSideEncryption).Marshal(header) } if dstOpts.ServerSideEncryption != nil { dstOpts.ServerSideEncryption.Marshal(header) } for k, v := range header { srcInfo.UserDefined[k] = v[0] } if _, err = l.Client.CopyObject(srcBucket, srcObject, dstBucket, dstObject, srcInfo.UserDefined); err != nil { return objInfo, minio.ErrorRespToObjectError(err, srcBucket, srcObject) } return l.GetObjectInfo(ctx, dstBucket, dstObject, dstOpts) } // DeleteObject deletes a blob in bucket func (l *s3Objects) DeleteObject(ctx context.Context, bucket string, object string) error { err := l.Client.RemoveObject(bucket, object) if err != nil { return minio.ErrorRespToObjectError(err, bucket, object) } return nil } func (l *s3Objects) DeleteObjects(ctx context.Context, bucket string, objects []string) ([]error, error) { errs := make([]error, len(objects)) for idx, object := range objects { errs[idx] = l.DeleteObject(ctx, bucket, object) } return errs, nil } // ListMultipartUploads lists all multipart uploads. func (l *s3Objects) ListMultipartUploads(ctx context.Context, bucket string, prefix string, keyMarker string, uploadIDMarker string, delimiter string, maxUploads int) (lmi minio.ListMultipartsInfo, e error) { result, err := l.Client.ListMultipartUploads(bucket, prefix, keyMarker, uploadIDMarker, delimiter, maxUploads) if err != nil { return lmi, err } return minio.FromMinioClientListMultipartsInfo(result), nil } // NewMultipartUpload upload object in multiple parts func (l *s3Objects) NewMultipartUpload(ctx context.Context, bucket string, object string, o minio.ObjectOptions) (uploadID string, err error) { // Create PutObject options opts := miniogo.PutObjectOptions{UserMetadata: o.UserDefined, ServerSideEncryption: o.ServerSideEncryption} uploadID, err = l.Client.NewMultipartUpload(bucket, object, opts) if err != nil { return uploadID, minio.ErrorRespToObjectError(err, bucket, object) } return uploadID, nil } // PutObjectPart puts a part of object in bucket func (l *s3Objects) PutObjectPart(ctx context.Context, bucket string, object string, uploadID string, partID int, r *minio.PutObjReader, opts minio.ObjectOptions) (pi minio.PartInfo, e error) { data := r.Reader info, err := l.Client.PutObjectPart(bucket, object, uploadID, partID, data, data.Size(), data.MD5Base64String(), data.SHA256HexString(), opts.ServerSideEncryption) if err != nil { return pi, minio.ErrorRespToObjectError(err, bucket, object) } return minio.FromMinioClientObjectPart(info), nil } // CopyObjectPart creates a part in a multipart upload by copying // existing object or a part of it. func (l *s3Objects) CopyObjectPart(ctx context.Context, srcBucket, srcObject, destBucket, destObject, uploadID string, partID int, startOffset, length int64, srcInfo minio.ObjectInfo, srcOpts, dstOpts minio.ObjectOptions) (p minio.PartInfo, err error) { if srcOpts.CheckCopyPrecondFn != nil && srcOpts.CheckCopyPrecondFn(srcInfo, "") { return minio.PartInfo{}, minio.PreConditionFailed{} } srcInfo.UserDefined = map[string]string{ "x-amz-copy-source-if-match": srcInfo.ETag, } header := make(http.Header) if srcOpts.ServerSideEncryption != nil { encrypt.SSECopy(srcOpts.ServerSideEncryption).Marshal(header) } if dstOpts.ServerSideEncryption != nil { dstOpts.ServerSideEncryption.Marshal(header) } for k, v := range header { srcInfo.UserDefined[k] = v[0] } completePart, err := l.Client.CopyObjectPart(srcBucket, srcObject, destBucket, destObject, uploadID, partID, startOffset, length, srcInfo.UserDefined) if err != nil { return p, minio.ErrorRespToObjectError(err, srcBucket, srcObject) } p.PartNumber = completePart.PartNumber p.ETag = completePart.ETag return p, nil } // ListObjectParts returns all object parts for specified object in specified bucket func (l *s3Objects) ListObjectParts(ctx context.Context, bucket string, object string, uploadID string, partNumberMarker int, maxParts int, opts minio.ObjectOptions) (lpi minio.ListPartsInfo, e error) { result, err := l.Client.ListObjectParts(bucket, object, uploadID, partNumberMarker, maxParts) if err != nil { return lpi, minio.ErrorRespToObjectError(err, bucket, object) } return minio.FromMinioClientListPartsInfo(result), nil } // AbortMultipartUpload aborts a ongoing multipart upload func (l *s3Objects) AbortMultipartUpload(ctx context.Context, bucket string, object string, uploadID string) error { err := l.Client.AbortMultipartUpload(bucket, object, uploadID) return minio.ErrorRespToObjectError(err, bucket, object) } // CompleteMultipartUpload completes ongoing multipart upload and finalizes object func (l *s3Objects) CompleteMultipartUpload(ctx context.Context, bucket string, object string, uploadID string, uploadedParts []minio.CompletePart, opts minio.ObjectOptions) (oi minio.ObjectInfo, e error) { etag, err := l.Client.CompleteMultipartUpload(bucket, object, uploadID, minio.ToMinioClientCompleteParts(uploadedParts)) if err != nil { return oi, minio.ErrorRespToObjectError(err, bucket, object) } return minio.ObjectInfo{Bucket: bucket, Name: object, ETag: etag}, nil } // SetBucketPolicy sets policy on bucket func (l *s3Objects) SetBucketPolicy(ctx context.Context, bucket string, bucketPolicy *policy.Policy) error { data, err := json.Marshal(bucketPolicy) if err != nil { // This should not happen. logger.LogIf(ctx, err) return minio.ErrorRespToObjectError(err, bucket) } if err := l.Client.SetBucketPolicy(bucket, string(data)); err != nil { return minio.ErrorRespToObjectError(err, bucket) } return nil } // GetBucketPolicy will get policy on bucket func (l *s3Objects) GetBucketPolicy(ctx context.Context, bucket string) (*policy.Policy, error) { data, err := l.Client.GetBucketPolicy(bucket) if err != nil { return nil, minio.ErrorRespToObjectError(err, bucket) } bucketPolicy, err := policy.ParseConfig(strings.NewReader(data), bucket) return bucketPolicy, minio.ErrorRespToObjectError(err, bucket) } // DeleteBucketPolicy deletes all policies on bucket func (l *s3Objects) DeleteBucketPolicy(ctx context.Context, bucket string) error { if err := l.Client.SetBucketPolicy(bucket, ""); err != nil { return minio.ErrorRespToObjectError(err, bucket, "") } return nil } // IsCompressionSupported returns whether compression is applicable for this layer. func (l *s3Objects) IsCompressionSupported() bool { return false } // IsEncryptionSupported returns whether server side encryption is implemented for this layer. func (l *s3Objects) IsEncryptionSupported() bool { return minio.GlobalKMS != nil || len(minio.GlobalGatewaySSE) > 0 }