你好,问下,接口返回解密之后的证书文件内容,如何转成 pem证书呢？php版本的,我自己手动复制粘贴,创建.pem的文件,报错 openssl_x509_read(): supplied parameter cannot be coerced into an X509 certificate

{     "code": "SIGN_ERROR",     "detail": {         "detail": {             "issue": "sign not match"         },         "field": "signature",         "location": "authorization",         "sign_information": {             "method": "GET",             "sign_message_length": 66,             "truncated_sign_message": "GET\n/v3/certificates\n1601277177\n593BEC0C930BF1AFEB40B4A08C8FB242\n\n",             "url": "/v3/certificates"         }     },     "message": "错误的签名，验签失败" }