public static bool TryParse(string encodedCipher, out AuthorizationCipher decodedCipher)
{
if (string.IsNullOrWhiteSpace(encodedCipher))
{
decodedCipher = null;
return false;
}
IDictionary<string, string> cipherValues = ParseMultiValueHeader(encodedCipher);
if (cipherValues.Count < 3)
{
decodedCipher = null;
return false;
}
short version = 0;
if (!short.TryParse(cipherValues["v"], out version) || version < 1)
{
decodedCipher = null;
return false;
}
byte[] nonce = ConvertHexadecimalToByteArray(cipherValues["n"]);
if (nonce == null)
{
decodedCipher = null;
return false;
}
CipherSource source;
byte[] cryptogram;
if (cipherValues.ContainsKey("s"))
{
source = CipherSource.Server;
cryptogram = ConvertHexadecimalToByteArray(cipherValues["s"]);
}
else if (cipherValues.ContainsKey("c"))
{
source = CipherSource.Client;
cryptogram = ConvertHexadecimalToByteArray(cipherValues["c"]);
}
else
{
decodedCipher = null;
return false;
}
if (cryptogram == null)
{
decodedCipher = null;
return false;
}
decodedCipher = new AuthorizationCipher() { Source = source, Version = version, Nonce = nonce, Cryptogram = cryptogram };
return true;
}
/// <summary>
/// Validates the cipher to ensure it represents a legitimately requested callback.
/// </summary>
/// <param name="authorizationHeaderValue">A cipher value for this callback.</param>
/// <param name="callbackId">A <see cref="T:System.Guid"/> that serves as an identifier for the scheduled callback.</param>
/// <param name="callbackUri">An absolute <see cref="T:System.Uri"/> that will be requested on the callback.</param>
/// <returns>true if the cipher is valid, false if not.</returns>
public static bool Validate(string authorizationHeaderValue, Guid callbackId, Uri callbackUri)
{
if (string.IsNullOrEmpty(authorizationHeaderValue))
{
return(false);
}
if (Guid.Empty.Equals(callbackId))
{
return(false);
}
if (callbackUri == null || string.IsNullOrEmpty(callbackUri.OriginalString))
{
return(false);
}
AuthorizationCipher incomingCipher;
if (!AuthorizationCipher.TryParse(authorizationHeaderValue, out incomingCipher) || incomingCipher.Source != AuthorizationCipher.CipherSource.Server)
{
return(false);
}
short version = incomingCipher.Version;
switch (version)
{
case _CurrentVersion:
byte[] nonce = incomingCipher.Nonce;
byte[] clientKey = RetrieveClientKey();
byte[] subject = GetSubject(callbackUri);
byte[] clientCryptogram = BuildClientCryptogram(nonce, subject, clientKey);
byte[] responseId = GetResponseId(callbackId);
byte[] serverCryptogram = BuildServerCryptogram(nonce, clientCryptogram, responseId);
return(AreEqual(serverCryptogram, incomingCipher.Cryptogram));
default:
return(false);
}
}
public static bool TryParse(string encodedCipher, out AuthorizationCipher decodedCipher)
{
if (string.IsNullOrWhiteSpace(encodedCipher))
{
decodedCipher = null;
return(false);
}
IDictionary <string, string> cipherValues = ParseMultiValueHeader(encodedCipher);
if (cipherValues.Count < 3)
{
decodedCipher = null;
return(false);
}
short version = 0;
if (!short.TryParse(cipherValues["v"], out version) || version < 1)
{
decodedCipher = null;
return(false);
}
byte[] nonce = ConvertHexToByteArray(cipherValues["n"]);
if (nonce == null || nonce.Length == 0)
{
decodedCipher = null;
return(false);
}
CipherSource source;
byte[] cryptogram;
if (cipherValues.ContainsKey("s"))
{
source = CipherSource.Server;
cryptogram = ConvertHexToByteArray(cipherValues["s"]);
}
else if (cipherValues.ContainsKey("c"))
{
source = CipherSource.Client;
cryptogram = ConvertHexToByteArray(cipherValues["c"]);
}
else
{
decodedCipher = null;
return(false);
}
if (cryptogram == null || cryptogram.Length == 0)
{
decodedCipher = null;
return(false);
}
decodedCipher = new AuthorizationCipher()
{
Source = source, Version = version, Nonce = nonce, Cryptogram = cryptogram
};
return(true);
}
