如何使用PHP7.1将P7C文件转换为pem文件？

<?php
$p7cFile = 'path/to/your.p7c';
$pemPrivateKeyFile = 'path/to/private_key.pem';
$pemCertificateFile = 'path/to/certificate.pem';

// 读取P7C文件
$pkcs7 = file_get_contents($p7cFile);
$certs = [];
openssl_pkcs7_read($pkcs7, $certs);

// 导出私钥为PEM格式
$privateKey = '';
openssl_pkey_export($certs['pkey'], $privateKey);
file_put_contents($pemPrivateKeyFile, $privateKey);

// 导出证书为PEM格式
$certificate = '';
openssl_x509_export($certs[0], $certificate);
file_put_contents($pemCertificateFile, $certificate);

echo "转换完成！";
?>