/// <summary>
/// this method is used when client cannot connect to the internet or service is broken.
/// </summary>
/// <returns></returns>
public bool SNVerifyLocally()
{
if (string.IsNullOrEmpty(this.SN))
{
return(false);
}
try
{
RSAPublicKey rsaPublic = RSAPublicKey.FromXmlString(AppHelper.STR_PUBLIC_KEY);
byte[] decryptBytes = RSAHelper.Decrypt(Convert.FromBase64String(this.SN), rsaPublic);
string resultDecrypted = Encoding.UTF8.GetString(decryptBytes, 0, decryptBytes.Length);
string[] sns = resultDecrypted.Split(new char[] { '|' }, 3);
if (sns.Length == 2 || sns.Length == 3)
{
var localHash = sns[1];
var tmp = string.Format("{0}-{1}-{2}", this.AppId.Substring(0, 8), this.MAC, sns[0]).ToLower();
var data = (new EncDec()).GetMd5Hash(tmp);
if (data.ToLower() == localHash.ToLower())
{
if (sns.Length == 3)
{
DateTime expireDate = DateTime.Parse(sns[2]);
if (DateTime.Now > expireDate)
{
return(false);
}
}
return(true);
}
else
{
//the SN value might be modified by client user manually.
//Just keep the value that user modified.
return(false);
}
}
}
catch (Exception)
{
return(false);
}
return(false);
}
public static byte[] Decrypt(byte[] data, RSAPublicKey publicKey)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
if (publicKey == null)
{
throw new ArgumentNullException("publicKey");
}
int blockSize = publicKey.Modulus.Length;
return(Compute(data, publicKey, blockSize));
}
public static byte[] Sign(byte[] data, RSAPublicKey publicKey, HashAlgorithm hash)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
if (publicKey == null)
{
throw new ArgumentNullException("publicKey");
}
if (hash == null)
{
throw new ArgumentNullException("hash");
}
byte[] hashData = hash.ComputeHash(data);
byte[] signature = Encrypt(hashData, publicKey);
return(signature);
}
public static bool Verify(byte[] data, RSAPublicKey publicKey, HashAlgorithm hash, byte[] signature)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
if (publicKey == null)
{
throw new ArgumentNullException("publicKey");
}
if (hash == null)
{
throw new ArgumentNullException("hash");
}
if (signature == null)
{
throw new ArgumentNullException("signature");
}
byte[] hashData = hash.ComputeHash(data);
byte[] signatureHashData = Decrypt(signature, publicKey);
if (signatureHashData != null && signatureHashData.Length == hashData.Length)
{
for (int i = 0; i < signatureHashData.Length; i++)
{
if (signatureHashData[i] != hashData[i])
{
return(false);
}
}
return(true);
}
return(false);
}
public static RSAPublicKey FromXmlString(string xmlString)
{
if (string.IsNullOrEmpty(xmlString))
{
return(null);
}
try
{
using (XmlReader reader = XmlReader.Create(new StringReader(xmlString)))
{
if (!reader.ReadToFollowing("RSAKeyValue"))
{
return(null);
}
if (reader.LocalName != "Modulus" && !reader.ReadToFollowing("Modulus"))
{
return(null);
}
string modulus = reader.ReadElementContentAsString();
if (reader.LocalName != "Exponent" && !reader.ReadToFollowing("Exponent"))
{
return(null);
}
string exponent = reader.ReadElementContentAsString();
RSAPublicKey publicKey = new RSAPublicKey();
publicKey.Modulus = Convert.FromBase64String(modulus);
publicKey.Exponent = Convert.FromBase64String(exponent);
return(publicKey);
}
}
catch
{
return(null);
}
}
