为何会如此提示？批量删除。

发送的body如下：


<?xml version="1.0" encoding="UTF-8"?><Delete><Quiet>false</Quiet><Object><Key>1</Key></Object><Object><Key>2</Key></Object><Object><Key>3</Key></Object><Object><Key>4</Key></Object><Object><Key>5</Key></Object></Delete>

oss返回报文如下：
<?xml version="1.0" encoding="UTF-8"?>
<Error>
    <Code>InvalidDigest</Code>
    <Message>The Content-MD5 you specified was invalid.</Message>
    <Content-MD5>84b76f59781587963a7f95a1d461b01e</Content-MD5>
    <RequestId>52C1A3ED8FA7C7844392A252</RequestId>
    <HostId>transfile.oss-cn-hangzhou.aliyuncs.com</HostId>
</Error>

发送的md5为：84b76f59781587963a7f95a1d461b01e


生成代码如下：
if (is_array($object)) {
    $xml = '<?xml version="1.0" encoding="UTF-8"?><Delete><Quiet>false</Quiet>%s</Delete>';
    $template = '<Object><Key>%s</Key></Object>';
    $tempstr = '';

    foreach ($object as $obj) {
        $tempstr .= sprintf($template,$obj);
    }

    $xml = sprintf($xml,$tempstr);
    $header['content-length'] = strlen($xml);
    $header['content-md5'] = md5($xml);
    $opts['content'] = $xml;
}