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//-----------------------------------------------------------------------
// <copyright file="OAuthAuthorizationServer.cs" company="Outercurve Foundation">
// Copyright (c) Outercurve Foundation. All rights reserved.
// </copyright>
//-----------------------------------------------------------------------
namespace RelyingPartyLogic {
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Web;
using DotNetOpenAuth.Messaging.Bindings;
using DotNetOpenAuth.OAuth2;
using DotNetOpenAuth.OAuth2.ChannelElements;
using DotNetOpenAuth.OAuth2.Messages;
/// <summary>
/// Provides OAuth 2.0 authorization server information to DotNetOpenAuth.
/// </summary>
public class OAuthAuthorizationServer : IAuthorizationServer {
private static readonly RSACryptoServiceProvider SigningKey = new RSACryptoServiceProvider();
private readonly INonceStore nonceStore = new NonceDbStore();
/// <summary>
/// Initializes a new instance of the <see cref="OAuthAuthorizationServer"/> class.
/// </summary>
public OAuthAuthorizationServer() {
this.CryptoKeyStore = new RelyingPartyApplicationDbStore();
}
#region IAuthorizationServer Members
public ICryptoKeyStore CryptoKeyStore { get; private set; }
/// <summary>
/// Gets the authorization code nonce store to use to ensure that authorization codes can only be used once.
/// </summary>
/// <value>The authorization code nonce store.</value>
public INonceStore VerificationCodeNonceStore {
get { return this.nonceStore; }
}
/// <summary>
/// Gets the crypto service provider with the asymmetric private key to use for signing access tokens.
/// </summary>
/// <value>
/// Must not be null, and must contain the private key.
/// </value>
/// <returns>A crypto service provider instance that contains the private key.</returns>
public RSACryptoServiceProvider AccessTokenSigningKey {
get { return SigningKey; }
}
/// <summary>
/// Obtains the lifetime for a new access token.
/// </summary>
/// <param name="accessTokenRequestMessage">Details regarding the resources that the access token will grant access to, and the identity of the client
/// that will receive that access.
/// Based on this information the receiving resource server can be determined and the lifetime of the access
/// token can be set based on the sensitivity of the resources.</param>
/// <returns>
/// Receives the lifetime for this access token. Note that within this lifetime, authorization <i>may</i> not be revokable.
/// Short lifetimes are recommended (i.e. one hour), particularly when the client is not authenticated or
/// the resources to which access is being granted are sensitive.
/// </returns>
public TimeSpan GetAccessTokenLifetime(IAccessTokenRequest accessTokenRequestMessage) {
return TimeSpan.FromHours(1);
}
/// <summary>
/// Obtains the encryption key for an access token being created.
/// </summary>
/// <param name="accessTokenRequestMessage">Details regarding the resources that the access token will grant access to, and the identity of the client
/// that will receive that access.
/// Based on this information the receiving resource server can be determined and the lifetime of the access
/// token can be set based on the sensitivity of the resources.</param>
/// <returns>
/// The crypto service provider with the asymmetric public key to use for encrypting access tokens for a specific resource server.
/// The caller is responsible to dispose of this value.
/// </returns>
public RSACryptoServiceProvider GetResourceServerEncryptionKey(IAccessTokenRequest accessTokenRequestMessage) {
// For this sample, we assume just one resource server.
// If this authorization server needs to mint access tokens for more than one resource server,
// we'd look at the request message passed to us and decide which public key to return.
return OAuthResourceServer.CreateRSA();
}
/// <summary>
/// Gets the client with a given identifier.
/// </summary>
/// <param name="clientIdentifier">The client identifier.</param>
/// <returns>The client registration. Never null.</returns>
/// <exception cref="ArgumentException">Thrown when no client with the given identifier is registered with this authorization server.</exception>
public IClientDescription GetClient(string clientIdentifier) {
try {
return Database.DataContext.Clients.First(c => c.ClientIdentifier == clientIdentifier);
} catch (InvalidOperationException ex) {
throw new ArgumentOutOfRangeException("No client by that identifier.", ex);
}
}
/// <summary>
/// Determines whether a described authorization is (still) valid.
/// </summary>
/// <param name="authorization">The authorization.</param>
/// <returns>
/// <c>true</c> if the original authorization is still valid; otherwise, <c>false</c>.
/// </returns>
/// <remarks>
/// <para>When establishing that an authorization is still valid,
/// it's very important to only match on recorded authorizations that
/// meet these criteria:</para>
/// 1) The client identifier matches.
/// 2) The user account matches.
/// 3) The scope on the recorded authorization must include all scopes in the given authorization.
/// 4) The date the recorded authorization was issued must be <em>no later</em> that the date the given authorization was issued.
/// <para>One possible scenario is where the user authorized a client, later revoked authorization,
/// and even later reinstated authorization. This subsequent recorded authorization
/// would not satisfy requirement #4 in the above list. This is important because the revocation
/// the user went through should invalidate all previously issued tokens as a matter of
/// security in the event the user was revoking access in order to sever authorization on a stolen
/// account or piece of hardware in which the tokens were stored. </para>
/// </remarks>
public bool IsAuthorizationValid(IAuthorizationDescription authorization) {
return this.IsAuthorizationValid(authorization.Scope, authorization.ClientIdentifier, authorization.UtcIssued, authorization.User);
}
/// <summary>
/// Determines whether a given set of resource owner credentials is valid based on the authorization server's user database.
/// </summary>
/// <param name="userName">Username on the account.</param>
/// <param name="password">The user's password.</param>
/// <returns>
/// <c>true</c> if the given credentials are valid; otherwise, <c>false</c>.
/// </returns>
/// <exception cref="NotSupportedException">May be thrown if the authorization server does not support the resource owner password credential grant type.</exception>
public bool IsResourceOwnerCredentialValid(string userName, string password) {
// This web site delegates user authentication to OpenID Providers, and as such no users have local passwords with this server.
throw new NotSupportedException();
}
#endregion
public bool CanBeAutoApproved(EndUserAuthorizationRequest authorizationRequest) {
if (authorizationRequest == null) {
throw new ArgumentNullException("authorizationRequest");
}
// NEVER issue an auto-approval to a client that would end up getting an access token immediately
// (without a client secret), as that would allow ANY client to spoof an approved client's identity
// and obtain unauthorized access to user data.
if (authorizationRequest.ResponseType == EndUserAuthorizationResponseType.AuthorizationCode) {
// Never issue auto-approval if the client secret is blank, since that too makes it easy to spoof
// a client's identity and obtain unauthorized access.
var requestingClient = Database.DataContext.Clients.First(c => c.ClientIdentifier == authorizationRequest.ClientIdentifier);
if (!string.IsNullOrEmpty(requestingClient.ClientSecret)) {
return this.IsAuthorizationValid(
authorizationRequest.Scope,
authorizationRequest.ClientIdentifier,
DateTime.UtcNow,
HttpContext.Current.User.Identity.Name);
}
}
// Default to not auto-approving.
return false;
}
private bool IsAuthorizationValid(HashSet<string> requestedScopes, string clientIdentifier, DateTime issuedUtc, string username) {
var grantedScopeStrings = from auth in Database.DataContext.ClientAuthorizations
where
auth.Client.ClientIdentifier == clientIdentifier &&
auth.CreatedOnUtc <= issuedUtc &&
(!auth.ExpirationDateUtc.HasValue || auth.ExpirationDateUtc.Value >= DateTime.UtcNow) &&
auth.User.AuthenticationTokens.Any(token => token.ClaimedIdentifier == username)
select auth.Scope;
if (!grantedScopeStrings.Any()) {
// No granted authorizations prior to the issuance of this token, so it must have been revoked.
// Even if later authorizations restore this client's ability to call in, we can't allow
// access tokens issued before the re-authorization because the revoked authorization should
// effectively and permanently revoke all access and refresh tokens.
return false;
}
var grantedScopes = new HashSet<string>(OAuthUtilities.ScopeStringComparer);
foreach (string scope in grantedScopeStrings) {
grantedScopes.UnionWith(OAuthUtilities.SplitScopes(scope));
}
return requestedScopes.IsSubsetOf(grantedScopes);
}
}
}
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