Fix SSE-C checksums (#19896)

Compression will be disabled by default if SSE-C is specified. So we can still honor SSE-C.

cmd/erasure-object.go

@@ -20,6 +20,7 @@ package cmd
 import (
 	"bytes"
 	"context"
+	"encoding/base64"
 	"errors"
 	"fmt"
 	"io"
@@ -276,7 +277,7 @@ func (er erasureObjects) GetObjectNInfo(ctx context.Context, bucket, object stri
 		return gr.WithCleanupFuncs(nsUnlocker), nil
 	}
 
-	fn, off, length, err := NewGetObjectReader(rs, objInfo, opts)
+	fn, off, length, err := NewGetObjectReader(rs, objInfo, opts, h)
 	if err != nil {
 		return nil, err
 	}
@@ -1355,6 +1356,12 @@ func (er erasureObjects) putObject(ctx context.Context, bucket string, object st
 	if opts.EncryptFn != nil {
 		fi.Checksum = opts.EncryptFn("object-checksum", fi.Checksum)
 	}
+	if userDefined[ReplicationSsecChecksumHeader] != "" {
+		if v, err := base64.StdEncoding.DecodeString(userDefined[ReplicationSsecChecksumHeader]); err == nil {
+			fi.Checksum = v
+		}
+	}
+	delete(userDefined, ReplicationSsecChecksumHeader)
 	uniqueID := mustGetUUID()
 	tempObj := uniqueID