/// <summary>
/// Computes the Client Assertion portion of the JWT
/// </summary>
/// <param name="header">The JSON Web Token header</param>
/// <param name="claimSet">The JSON Web Token claim set</param>
/// <param name="clientSecret">The client's secret</param>
/// <returns>The assertion</returns>
public string BuildAssertion(JWTHeader header, JWTClaimSet claimSet, string clientSecret)
{
// Serialize the header and claimSet
string serializedHeader = JsonConvert.SerializeObject(header);
string serializedClaimSet = JsonConvert.SerializeObject(claimSet);
// Base64Encode the header and claimSet
string encodedHeader = Convert.ToBase64String(UTF8Encoding.UTF8.GetBytes(serializedHeader));
string encodedClaimSet = Convert.ToBase64String(UTF8Encoding.UTF8.GetBytes(serializedClaimSet));
// Concatenate the header and the claims separated with a '.': [header].[claims]
string message = string.Join(".", encodedHeader, encodedClaimSet);
// Apply an HMAC/SHA-256 hash* to the concatenated content using the Client Secret as the key
HMACSHA256 hmac = new HMACSHA256(Encoding.UTF8.GetBytes(clientSecret));
byte[] hash = hmac.ComputeHash(Encoding.UTF8.GetBytes(message));
// Base64Encode the result of the hash
string signature = Convert.ToBase64String(hash);
// Combine the encoded elements as follows [header].[claims].[hash]
string assertion = string.Join(".", encodedHeader, encodedClaimSet, signature);
return assertion;
}
/// <summary>
/// Retrieves a new token from Webtrends auth service
/// </summary>
public string Execute()
{
var builder = new JWTBuilder();
var header = new JWTHeader
{
Type = "JWT",
Algorithm = "HS256"
};
var claimSet = new JWTClaimSet
{
Issuer = clientId,
Principal = clientId,
Audience = audience,
Expiration = DateTime.Now.AddSeconds(30),
Scope = scope
};
string assertion = builder.BuildAssertion(header, claimSet, clientSecret);
var client = new RestClient(authUrl);
var request = new RestRequest("token/", Method.POST);
request.AddParameter("client_id", clientId);
request.AddParameter("client_assertion", assertion);
request.AddParameter("grant_type", "client_credentials");
request.AddParameter("client_assertion_type", "urn:ietf:params:oauth:client-assertion-type:jwt-bearer");
var response = client.Execute(request).Content;
return (string)JObject.Parse(response)["access_token"];
}
/// <summary>
/// Retrieves a new token from Webtrends auth service
/// </summary>
public string Execute()
{
var builder = new JWTBuilder();
var header = new JWTHeader
{
Type = "JWT",
Algorithm = "HS256"
};
var claimSet = new JWTClaimSet
{
Issuer = clientId,
Principal = clientId,
Audience = audience,
Expiration = DateTime.Now.ToUniversalTime().AddSeconds(30),
Scope = scope
};
string assertion = builder.BuildAssertion(header, claimSet, clientSecret);
var client = new RestClient(authUrl);
var request = new RestRequest("token/", Method.POST);
request.AddParameter("client_id", clientId);
request.AddParameter("client_assertion", assertion);
request.AddParameter("grant_type", "client_credentials");
request.AddParameter("client_assertion_type", "urn:ietf:params:oauth:client-assertion-type:jwt-bearer");
var response = client.Execute(request).Content;
return (string)JObject.Parse(response)["access_token"];
}
/// <summary>
/// Computes the Client Assertion portion of the JWT
/// </summary>
/// <param name="header">The JSON Web Token header</param>
/// <param name="claimSet">The JSON Web Token claim set</param>
/// <param name="clientSecret">The client's secret</param>
/// <returns>The assertion</returns>
public string BuildAssertion(JWTHeader header, JWTClaimSet claimSet, string clientSecret)
{
// Serialize the header and claimSet
string serializedHeader = JsonConvert.SerializeObject(header);
string serializedClaimSet = JsonConvert.SerializeObject(claimSet);
// Base64Encode the header and claimSet
string encodedHeader = Convert.ToBase64String(UTF8Encoding.UTF8.GetBytes(serializedHeader));
string encodedClaimSet = Convert.ToBase64String(UTF8Encoding.UTF8.GetBytes(serializedClaimSet));
// Concatenate the header and the claims separated with a '.': [header].[claims]
string message = string.Join(".", encodedHeader, encodedClaimSet);
// Apply an HMAC/SHA-256 hash* to the concatenated content using the Client Secret as the key
HMACSHA256 hmac = new HMACSHA256(Encoding.UTF8.GetBytes(clientSecret));
byte[] hash = hmac.ComputeHash(Encoding.UTF8.GetBytes(message));
// Base64Encode the result of the hash
string signature = Convert.ToBase64String(hash);
// Combine the encoded elements as follows [header].[claims].[hash]
string assertion = string.Join(".", encodedHeader, encodedClaimSet, signature);
return assertion;
}
