public override SecurityToken CreateToken(SecurityTokenDescriptor tokenDescriptor)
{
if (tokenDescriptor == null)
{
throw new ArgumentNullException("tokenDescriptor");
}
var properties = new NameValueCollection
{
{ SimpleWebTokenConstants.Id, Guid.NewGuid().ToString() },
{ SimpleWebTokenConstants.Issuer, tokenDescriptor.TokenIssuerName },
{ SimpleWebTokenConstants.Audience, tokenDescriptor.AppliesToAddress },
{ SimpleWebTokenConstants.ExpiresOn, SecondsFromSwtBaseTime(tokenDescriptor.Lifetime.Expires) },
{ SimpleWebTokenConstants.ValidFrom, SecondsFromSwtBaseTime(tokenDescriptor.Lifetime.Created) }
};
foreach (var claim in tokenDescriptor.Subject.Claims)
{
properties.Add(claim.Type, claim.Value);
}
var token = new SimpleWebToken(properties, tokenDescriptor.SigningCredentials.SigningKey);
return(token);
}
/// <summary>
/// Parses the string token and generates a <see cref="SecurityToken"/>.
/// </summary>
/// <param name="serializedToken">The serialized form of the token received.</param>
/// <returns>The parsed form of the token.</returns>
protected SecurityToken ReadSecurityTokenFromString(string serializedToken)
{
if (String.IsNullOrEmpty(serializedToken))
{
throw new ArgumentException("The parameter 'serializedToken' cannot be null or empty string.");
}
// Create a collection of SWT name value pairs
var properties = ParseToken(serializedToken);
var swt = new SimpleWebToken(properties, serializedToken, null);
return(swt);
}
/// <summary>
/// Validates the signature on the incoming token.
/// </summary>
/// <param name="simpleWebToken">The incoming <see cref="SimpleWebToken"/>.</param>
protected virtual void ValidateSignature(SimpleWebToken simpleWebToken)
{
if (simpleWebToken == null)
{
throw new ArgumentNullException("simpleWebToken");
}
if (String.IsNullOrEmpty(simpleWebToken.SerializedToken) || String.IsNullOrEmpty(simpleWebToken.Signature))
{
throw new SecurityTokenValidationException("The token does not have a signature to verify");
}
var serializedToken = simpleWebToken.SerializedToken;
string unsignedToken = null;
// Find the last parameter. The signature must be last per SWT specification.
var lastSeparator = serializedToken.LastIndexOf(ParameterSeparator);
// Check whether the last parameter is an hmac.
if (lastSeparator > 0)
{
var lastParamStart = ParameterSeparator + SimpleWebTokenConstants.Signature + "=";
var lastParam = serializedToken.Substring(lastSeparator);
// Strip the trailing hmac to obtain the original unsigned string for later hmac verification.
if (lastParam.StartsWith(lastParamStart, StringComparison.Ordinal))
{
unsignedToken = serializedToken.Substring(0, lastSeparator);
}
}
var clause = new SimpleWebTokenKeyIdentifierClause(simpleWebToken.Audience);
InMemorySymmetricSecurityKey securityKey = null;
try
{
securityKey = (InMemorySymmetricSecurityKey)this.Configuration.IssuerTokenResolver.ResolveSecurityKey(clause);
}
catch (InvalidOperationException)
{
throw new SecurityTokenValidationException("A Symmetric key was not found for the given key identifier clause.");
}
var generatedSignature = GenerateSignature(unsignedToken, securityKey.GetSymmetricKey());
if (string.CompareOrdinal(HttpUtility.UrlDecode(generatedSignature), HttpUtility.UrlDecode(simpleWebToken.Signature)) != 0)
{
throw new SecurityTokenValidationException("The signature on the incoming token is invalid.");
}
}
/// <summary>Creates <see cref="Claim"/>'s from the incoming token.
/// </summary>
/// <param name="simpleWebToken">The incoming <see cref="SimpleWebToken"/>.</param>
/// <returns>A <see cref="ClaimsIdentity"/> created from the token.</returns>
protected virtual ClaimsIdentity CreateClaims(SimpleWebToken simpleWebToken)
{
if (simpleWebToken == null)
{
throw new ArgumentNullException("simpleWebToken");
}
var tokenProperties = simpleWebToken.GetAllProperties();
if (tokenProperties == null)
{
throw new SecurityTokenValidationException("No claims can be created from this Simple Web Token.");
}
if (Configuration.IssuerNameRegistry == null)
{
throw new InvalidOperationException("The Configuration.IssuerNameRegistry property of this SecurityTokenHandler is set to null. Tokens cannot be validated in this state.");
}
var normalizedIssuer = Configuration.IssuerNameRegistry.GetIssuerName(simpleWebToken);
var identity = new ClaimsIdentity(AuthenticationTypes.Federation);
foreach (string key in tokenProperties.Keys)
{
if (!IsReservedKeyName(key) && !string.IsNullOrEmpty(tokenProperties[key]))
{
identity.AddClaim(new Claim(key, tokenProperties[key], ClaimValueTypes.String, normalizedIssuer));
if (key == AcsNameClaimType)
{
// add a default name claim from the Name identifier claim.
identity.AddClaim(new Claim(DefaultNameClaimType, tokenProperties[key], ClaimValueTypes.String, normalizedIssuer));
}
}
}
return(identity);
}
