上代码

 $public_key = '-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
';
        $private_key = '-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----';
        $publicKey = openssl_pkey_get_public($public_key);
        $privateKey = openssl_pkey_get_private($private_key);
        $data = "加密文本";

        openssl_public_encrypt($data, $encrypted, $publicKey);//使用公钥加密,解密需要私钥解密
        $encrypted = base64_encode($encrypted);
        echo "公钥加密结果<br>" . $encrypted, "<hr>";

        openssl_private_decrypt(base64_decode($encrypted), $decrypted, $privateKey);//私钥解密,密文需要公钥加密
        echo "私钥解密结果<br>" . $decrypted, "<hr>";

        openssl_private_encrypt($data, $encrypted, $privateKey);//私钥加密,需要使用公钥解密
        $encrypted = base64_encode($encrypted);
        echo "私钥加密结果<br>" . $encrypted, "<hr>";

        openssl_public_decrypt(base64_decode($encrypted), $decrypted, $publicKey);//公钥解密,密文需要私钥加密
        echo "公钥解密结果<br>" . $decrypted, "<hr>";