/// <summary>
/// Initializes an authorization grant.
/// </summary>
/// <param name="statePrefix">Data to prefix OAuth state with to allow disambiguation between multiple concurrent authorization requests</param>
/// <param name="codeChallengeAlgorithm">Code challenge algorithm method</param>
public AuthorizationGrant(byte[] statePrefix, CodeChallengeAlgorithmType codeChallengeAlgorithm = CodeChallengeAlgorithmType.S256)
{
CodeChallengeAlgorithm = codeChallengeAlgorithm;
var rng = new RNGCryptoServiceProvider();
var random = new byte[32];
try
{
// Calculate random state.
rng.GetBytes(random);
var state = new byte[statePrefix.LongLength + random.LongLength];
try
{
Array.Copy(statePrefix, 0, state, 0, statePrefix.LongLength);
Array.Copy(random, 0, state, statePrefix.LongLength, random.LongLength);
State = new NetworkCredential("", Base64UrlEncodeNoPadding(state)).SecurePassword;
State.MakeReadOnly();
}
finally
{
// Sanitize!
for (long i = 0, n = state.LongLength; i < n; i++)
{
state[i] = 0;
}
}
// Calculate code verifier.
rng.GetBytes(random);
CodeVerifier = new NetworkCredential("", Base64UrlEncodeNoPadding(random)).SecurePassword;
CodeVerifier.MakeReadOnly();
}
finally
{
// Sanitize!
for (long i = 0, n = random.LongLength; i < n; i++)
{
random[i] = 0;
}
}
}
/// <summary>
/// Initializes an authorization grant.
/// </summary>
/// <param name="authorizationEndpoint">Authorization endpoint base URI</param>
/// <param name="redirectEndpoint">Redirection endpoint base URI</param>
/// <param name="clientId">Should be populated before requesting authorization.</param>
/// <param name="scope">Should be populated before requesting authorization. When empty, <c>scope</c> parameter is not included in authorization request URI.</param>
/// <param name="codeChallengeAlgorithm">Code challenge algorithm method</param>
public AuthorizationGrant(Uri authorizationEndpoint, Uri redirectEndpoint, string clientId, HashSet <string> scope, CodeChallengeAlgorithmType codeChallengeAlgorithm = CodeChallengeAlgorithmType.S256) :
this(Array.Empty <byte>(), codeChallengeAlgorithm)
{
AuthorizationEndpoint = authorizationEndpoint;
RedirectEndpoint = redirectEndpoint;
ClientId = clientId;
Scope = scope;
}
