Unity C# HttpwebRequestでhttps通信(オレオレ証明書エラーを回避) ref: http://qiita.com/satotin/items/a5392d04d2edad74f6ad

file0.txt

　TlsException: Invalid certificate received from server. Error code: 0xffffffff800b010f

file1.txt

using System.Net.Security;
using System.Security.Cryptography.X509Certificates;

file2.txt

    // 信頼できないSSL証明書を「問題なし」にするメソッド
    private bool OnRemoteCertificateValidationCallback(
      Object sender,
      X509Certificate certificate,
      X509Chain chain,
      SslPolicyErrors sslPolicyErrors)
    {
        return true;  // 「SSL証明書の使用は問題なし」と示す
    }

file3.txt

ServicePointManager.ServerCertificateValidationCallback =
　　　　　new RemoteCertificateValidationCallback(OnRemoteCertificateValidationCallback);
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(URLをここに書く);

file5.txt

System.Net.ServicePointManager.CertificatePolicy = new TrustAllCertificatePolicy();
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(URLをここに書く);

TrustAllCertificatePolicy.cs

using UnityEngine;
using System.Collections;

public class TrustAllCertificatePolicy : System.Net.ICertificatePolicy {

    public TrustAllCertificatePolicy() { }
    public bool CheckValidationResult(System.Net.ServicePoint sp,
        System.Security.Cryptography.X509Certificates.X509Certificate cert,
        System.Net.WebRequest req,
        int problem)
    {
        return true;
    }
}