Add support for bucket encryption feature (#8890)

- pkg/bucket/encryption provides support for handling bucket 
  encryption configuration
- changes under cmd/ provide support for AES256 algorithm only

Co-Authored-By: Poorna  <poornas@users.noreply.github.com>
Co-authored-by: Harshavardhana <harsha@minio.io>

cmd/peer-rest-client.go

@@ -31,6 +31,7 @@ import (
 	"github.com/minio/minio/cmd/http"
 	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/cmd/rest"
+	bucketsse "github.com/minio/minio/pkg/bucket/encryption"
 	"github.com/minio/minio/pkg/bucket/lifecycle"
 	objectlock "github.com/minio/minio/pkg/bucket/object/lock"
 	"github.com/minio/minio/pkg/bucket/policy"
@@ -411,6 +412,37 @@ func (client *peerRESTClient) SetBucketLifecycle(bucket string, bucketLifecycle
 	return nil
 }
 
+// RemoveBucketSSEConfig - Remove bucket encryption configuration on the peer node
+func (client *peerRESTClient) RemoveBucketSSEConfig(bucket string) error {
+	values := make(url.Values)
+	values.Set(peerRESTBucket, bucket)
+	respBody, err := client.call(peerRESTMethodBucketEncryptionRemove, values, nil, -1)
+	if err != nil {
+		return err
+	}
+	defer http.DrainBody(respBody)
+	return nil
+}
+
+// SetBucketSSEConfig - Set bucket encryption configuration on the peer node
+func (client *peerRESTClient) SetBucketSSEConfig(bucket string, encConfig *bucketsse.BucketSSEConfig) error {
+	values := make(url.Values)
+	values.Set(peerRESTBucket, bucket)
+
+	var reader bytes.Buffer
+	err := gob.NewEncoder(&reader).Encode(encConfig)
+	if err != nil {
+		return err
+	}
+
+	respBody, err := client.call(peerRESTMethodBucketEncryptionSet, values, &reader, -1)
+	if err != nil {
+		return err
+	}
+	defer http.DrainBody(respBody)
+	return nil
+}
+
 // PutBucketNotification - Put bucket notification on the peer node.
 func (client *peerRESTClient) PutBucketNotification(bucket string, rulesMap event.RulesMap) error {
 	values := make(url.Values)