// private methods
private Gudge.Samples.Security.RSTRSTR.RequestSecurityTokenResponse Issue(Gudge.Samples.Security.RSTRSTR.RequestSecurityToken rst)
{
// If rst is null, we're toast
if (rst == null)
throw new ArgumentNullException("rst");
// Create an RSTR object
Gudge.Samples.Security.RSTRSTR.RequestSecurityTokenResponse rstr = new Gudge.Samples.Security.RSTRSTR.RequestSecurityTokenResponse();
// Figure out the token type being requested
string tokenType = GetTokenType(rst);
Console.WriteLine("Issue: Request for token type {0}", tokenType);
// Figure out which key we're going to sign the token with...
SecurityKey signingKey = GetSigningKey();
SecurityKeyIdentifier signingKeyIdentifier = GetSigningKeyIdentifier();
SecurityKeyIdentifier proofKeyIdentifier = null;
if (rst.IsProofKeyAsymmetric())
{
Console.WriteLine("Retrieving Asymmetric Proof Key");
// Asymmetric proof key
proofKeyIdentifier = GetAsymmetricProofKey(rst);
}
else
{
// Symmetric proof key
Console.WriteLine("Constructing Symmetric Proof Key");
// Construct session key. This is the symmetric key that the client and the service will share.
// It actually appears twice in the response message; once for the service and
// once for the client. In the former case, it is typically embedded in the issued token,
// in the latter case, it is returned in a wst:RequestedProofToken element.
byte[] sessionKey = GetSessionKey(rst, rstr);
// Get token to use when encrypting key material for the service
SecurityToken encryptingToken = GetEncryptingToken(rst);
// Encrypt the session key for the service
byte[] encryptedKey = GetEncryptedKey(encryptingToken, sessionKey, out proofKeyIdentifier);
}
// Issued tokens are valid for 12 hours by default
DateTime effectiveTime = DateTime.Now;
DateTime expirationTime = DateTime.Now + new TimeSpan(12, 0, 0);
SecurityToken st = null;
switch (tokenType)
{
case "http://docs.oasis-open.org/wss/oasis-wss-saml-token-profile-1.1#SAMLV1.1":
st = CreateSAMLToken(effectiveTime, expirationTime, signingKey, signingKeyIdentifier, proofKeyIdentifier, rst.ClaimRequirements );
break;
default:
throw new Exception("Unsupported Token Type");
}
rstr.RequestedSecurityToken = st;
rstr.Context = rst.Context;
rstr.TokenType = tokenType;
rstr.RequestedAttachedReference = GetInternalSecurityKeyIdentifier(st)[0];
rstr.RequestedUnattachedReference = GetExternalSecurityKeyIdentifier(st)[0];
return rstr;
}
private SecurityKeyIdentifier GetAsymmetricProofKey(Gudge.Samples.Security.RSTRSTR.RequestSecurityToken rst)
{
return GetInternalSecurityKeyIdentifier(rst.ProofKey);
}
// This method determines the security token that contains the key material that
// the STS should encrypt a session key with in order
// for the service the issued token is intended for to be able to extract that session key
private SecurityToken GetEncryptingToken(Gudge.Samples.Security.RSTRSTR.RequestSecurityToken rst)
{
// If rst is null, we're toast
if (rst == null)
throw new ArgumentNullException("rst");
// Set encryptingToken to null
SecurityToken encryptingToken = null;
// ... Open the LocalMachine store in My for read-only access
X509Store store = new X509Store(StoreName.TrustedPeople, StoreLocation.LocalMachine);
store.Open(OpenFlags.ReadOnly);
// Find the "localhost" cert ...
foreach (X509Certificate2 cert in store.Certificates)
if (cert.SubjectName.Name == "CN=RPKey")
{
// ... and set encryptingToken to that cert
encryptingToken = new X509SecurityToken(cert);
break;
}
// Don't forget to close the store
store.Close();
// return the token
return encryptingToken;
}
private byte[] GetSessionKey(Gudge.Samples.Security.RSTRSTR.RequestSecurityToken rst, Gudge.Samples.Security.RSTRSTR.RequestSecurityTokenResponse rstr)
{
// If rst is null, we're toast
if (rst == null)
throw new ArgumentNullException("rst");
// If rstr is null, we're toast
if (rstr == null)
throw new ArgumentNullException("rstr");
// Figure out the keySize
int keySize = 256;
if (rst.KeySize != 0)
keySize = rst.KeySize;
Console.WriteLine("Proof key size {0}", keySize);
// Figure out whether we're using Combined or Issuer entropy.
byte[] sessionKey = null;
byte[] senderEntropy = GetSenderEntropy(rst);
byte[] issuerEntropy = GetIssuerEntropy(keySize);
RNGCryptoServiceProvider random = new RNGCryptoServiceProvider();
if (senderEntropy != null)
{
// Combined entropy
Console.WriteLine("Combined Entropy");
sessionKey = rstr.ComputeCombinedKey(senderEntropy, issuerEntropy, keySize);
rstr.IssuerEntropy = new BinarySecretSecurityToken ( issuerEntropy );
rstr.ComputeKey = true;
}
else
{
// Issuer-only entropy
Console.WriteLine("Issuer-only entropy");
sessionKey = issuerEntropy;
rstr.RequestedProofToken = new BinarySecretSecurityToken(sessionKey);
}
rstr.KeySize = keySize;
return sessionKey;
}
private byte[] GetSenderEntropy(Gudge.Samples.Security.RSTRSTR.RequestSecurityToken rst)
{
// If rst is null, we're toast
if (rst == null)
throw new ArgumentNullException("rst");
SecurityToken senderEntropyToken = rst.RequestorEntropy;
byte[] senderEntropy = null;
if (senderEntropyToken != null)
{
BinarySecretSecurityToken bsst = senderEntropyToken as BinarySecretSecurityToken;
if (bsst != null)
senderEntropy = bsst.GetKeyBytes();
}
return senderEntropy;
}
// This method determines the token type for the service the issued token is intended for.
private string GetTokenType(Gudge.Samples.Security.RSTRSTR.RequestSecurityToken rst)
{
// If rst is null, we're toast
if (rst == null)
throw new ArgumentNullException("rst");
// Set tokenType to null
string tokenType = null;
// If there is no service URI or we don't have a tokenType registered for that service URI...
tokenType = rst.TokenType;
// return the tokenType
return tokenType;
}
