Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Core / CSharp / MS / Internal / AppModel / CustomCredentialPolicy.cs / 1305600 / CustomCredentialPolicy.cs
//------------------------------------------------------------------------------ // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // Description: // // This creates and registers a custom ICredentialPolicy that will be used // whenever a server sends a 401 UNAUTHORIZED in response to a WebRequest. The // .NET framework will call ShouldSendCredential to determine if credentials // should be sent. // // Our policy is to go ahead and send whatever credentials there might be, // EXCEPT if we are using default credentials and the request is not going to // an Intranet, Local Machine or Trusted domain. // //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! // IMPORTANT: We are creating an instance of IInternetSecurityManager here. This // is currently also done in the AppSecurityManager at the Framework level. Any // modification to either of these classes--especially concerning MapUrlToZone-- // should be considered for both classes. //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! // // An IInternetSecurityManagerSite is not currently needed here, because the // only method of IInternetSecurityManager that we are calling is MapUrlToZone, // and that does not prompt the user. // // History: // 03/15/2006: [....] - Initial creation. //----------------------------------------------------------------------------- using System; using System.Collections.Generic; using System.Net; using System.Runtime.InteropServices; using System.Security; using System.Security.Permissions; using MS.Internal.PresentationCore; using MS.Win32; namespace MS.Internal.AppModel { [FriendAccessAllowed] internal class CustomCredentialPolicy : ICredentialPolicy { ////// Critical - Accesses critical members /// PublicOK - Nothing is exposed, and nothing depends on user input. We're just creating objects for use later. /// [SecurityCritical, SecurityTreatAsSafe] static CustomCredentialPolicy() { _lockObj = new object(); _initialized = false; } ////// Critical - Access critical member _environmentPermissionSet /// PublicOK - Nothing is exposed, and nothing depends on user input. We're just creating objects for use later. /// [SecurityCritical, SecurityTreatAsSafe] public CustomCredentialPolicy() { _environmentPermissionSet = new PermissionSet(null); _environmentPermissionSet.AddPermission(new EnvironmentPermission(EnvironmentPermissionAccess.Read, "USERDOMAIN")); _environmentPermissionSet.AddPermission(new EnvironmentPermission(EnvironmentPermissionAccess.Read, "USERNAME")); } ////// Critical - Asserts for permission to set the credential policy. /// TreatAsSafe - Nothing is exposed. This method is safe to call at any time. /// [SecurityCritical, SecurityTreatAsSafe] static internal void EnsureCustomCredentialPolicy() { if (!_initialized) { lock (_lockObj) { if (!_initialized) { new SecurityPermission(SecurityPermissionFlag.ControlPolicy).Assert(); // BlessedAssert: try { // We should allow an application to set its own credential policy, if it has permssion to. // We do not want to overwrite the application's setting. // Check whether it is already set before setting it. // The default of this property is null. It demands ControlPolicy permission to be set. if (AuthenticationManager.CredentialPolicy == null) { AuthenticationManager.CredentialPolicy = new CustomCredentialPolicy(); } _initialized = true; } finally { CodeAccessPermission.RevertAssert(); } } } } } #region ICredentialPolicy Members ////// Critical - Calls SecurityCritical method IsDefaultCredentials. /// TreatAsSafe - This is called by the framework to determine if credentials should be sent /// in response to the server sending a 401. The challengUri and request are /// coming from the app; the credential and authenticationModule are coming /// from the framework. The only ouput is whether or not credentials should /// be sent, which is not critical. /// [SecurityCritical, SecurityTreatAsSafe] public bool ShouldSendCredential(Uri challengeUri, WebRequest request, NetworkCredential credential, IAuthenticationModule authenticationModule) { switch (MapUrlToZone(challengeUri)) { // Always send credentials (including default credentials) to these zones case SecurityZone.Intranet: case SecurityZone.Trusted: case SecurityZone.MyComputer: return true; // Don't send default credentials to any of these zones case SecurityZone.Internet: case SecurityZone.Untrusted: default: return !IsDefaultCredentials(credential); } } #endregion ////// Critical - Asserts for permission to examine the user name and password. They are /// only checked to see if they are non-null, and not exposed, but the /// fact that default credential are being used and are available might /// something we would not want revealed, which is why it is not TAS. /// [SecurityCritical] private bool IsDefaultCredentials(NetworkCredential credential) { _environmentPermissionSet.Assert(); // BlessedAssert: try { return credential == CredentialCache.DefaultCredentials; } finally { CodeAccessPermission.RevertAssert(); } } ////// Critical - Call critical method MapUrlToZone. /// TreatAsSafe - Returns the zone of the uri, which is not critical. /// [SecurityCritical, SecurityTreatAsSafe] internal static SecurityZone MapUrlToZone(Uri uri) { EnsureSecurityManager(); int targetZone; _securityManager.MapUrlToZone(BindUriHelper.UriToString(uri), out targetZone, 0); // The enum is directly mappable, but taking no chances... switch (targetZone) { case NativeMethods.URLZONE_LOCAL_MACHINE: return SecurityZone.MyComputer; case NativeMethods.URLZONE_INTERNET: return SecurityZone.Internet; case NativeMethods.URLZONE_INTRANET: return SecurityZone.Intranet; case NativeMethods.URLZONE_TRUSTED: return SecurityZone.Trusted; case NativeMethods.URLZONE_UNTRUSTED: return SecurityZone.Untrusted; } return SecurityZone.NoZone; } ////// Critical - Accesses critical member _securityManager and calls the SUC'd MapUrlToZone. /// TreatAsSafe - Doesn't expose anything, doesn't take user input, safe to call at any time. /// [SecurityCritical, SecurityTreatAsSafe] private static void EnsureSecurityManager() { // IMPORTANT: See comments in header r.e. IInternetSecurityManager if (_securityManager == null) { lock (_lockObj) { if (_securityManager == null) { _securityManager = (UnsafeNativeMethods.IInternetSecurityManager)new InternetSecurityManager(); } } } } [ComImport, ComVisible(false), Guid("7b8a2d94-0ac9-11d1-896c-00c04Fb6bfc4")] private class InternetSecurityManager { } ////// Critical - requires an elevation to create. /// [SecurityCritical] private static UnsafeNativeMethods.IInternetSecurityManager _securityManager; [SecurityCritical] private static object _lockObj; [SecurityCritical] private static bool _initialized; [SecurityCritical] PermissionSet _environmentPermissionSet; } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved. //------------------------------------------------------------------------------ // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // Description: // // This creates and registers a custom ICredentialPolicy that will be used // whenever a server sends a 401 UNAUTHORIZED in response to a WebRequest. The // .NET framework will call ShouldSendCredential to determine if credentials // should be sent. // // Our policy is to go ahead and send whatever credentials there might be, // EXCEPT if we are using default credentials and the request is not going to // an Intranet, Local Machine or Trusted domain. // //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! // IMPORTANT: We are creating an instance of IInternetSecurityManager here. This // is currently also done in the AppSecurityManager at the Framework level. Any // modification to either of these classes--especially concerning MapUrlToZone-- // should be considered for both classes. //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! // // An IInternetSecurityManagerSite is not currently needed here, because the // only method of IInternetSecurityManager that we are calling is MapUrlToZone, // and that does not prompt the user. // // History: // 03/15/2006: [....] - Initial creation. //----------------------------------------------------------------------------- using System; using System.Collections.Generic; using System.Net; using System.Runtime.InteropServices; using System.Security; using System.Security.Permissions; using MS.Internal.PresentationCore; using MS.Win32; namespace MS.Internal.AppModel { [FriendAccessAllowed] internal class CustomCredentialPolicy : ICredentialPolicy { ////// Critical - Accesses critical members /// PublicOK - Nothing is exposed, and nothing depends on user input. We're just creating objects for use later. /// [SecurityCritical, SecurityTreatAsSafe] static CustomCredentialPolicy() { _lockObj = new object(); _initialized = false; } ////// Critical - Access critical member _environmentPermissionSet /// PublicOK - Nothing is exposed, and nothing depends on user input. We're just creating objects for use later. /// [SecurityCritical, SecurityTreatAsSafe] public CustomCredentialPolicy() { _environmentPermissionSet = new PermissionSet(null); _environmentPermissionSet.AddPermission(new EnvironmentPermission(EnvironmentPermissionAccess.Read, "USERDOMAIN")); _environmentPermissionSet.AddPermission(new EnvironmentPermission(EnvironmentPermissionAccess.Read, "USERNAME")); } ////// Critical - Asserts for permission to set the credential policy. /// TreatAsSafe - Nothing is exposed. This method is safe to call at any time. /// [SecurityCritical, SecurityTreatAsSafe] static internal void EnsureCustomCredentialPolicy() { if (!_initialized) { lock (_lockObj) { if (!_initialized) { new SecurityPermission(SecurityPermissionFlag.ControlPolicy).Assert(); // BlessedAssert: try { // We should allow an application to set its own credential policy, if it has permssion to. // We do not want to overwrite the application's setting. // Check whether it is already set before setting it. // The default of this property is null. It demands ControlPolicy permission to be set. if (AuthenticationManager.CredentialPolicy == null) { AuthenticationManager.CredentialPolicy = new CustomCredentialPolicy(); } _initialized = true; } finally { CodeAccessPermission.RevertAssert(); } } } } } #region ICredentialPolicy Members ////// Critical - Calls SecurityCritical method IsDefaultCredentials. /// TreatAsSafe - This is called by the framework to determine if credentials should be sent /// in response to the server sending a 401. The challengUri and request are /// coming from the app; the credential and authenticationModule are coming /// from the framework. The only ouput is whether or not credentials should /// be sent, which is not critical. /// [SecurityCritical, SecurityTreatAsSafe] public bool ShouldSendCredential(Uri challengeUri, WebRequest request, NetworkCredential credential, IAuthenticationModule authenticationModule) { switch (MapUrlToZone(challengeUri)) { // Always send credentials (including default credentials) to these zones case SecurityZone.Intranet: case SecurityZone.Trusted: case SecurityZone.MyComputer: return true; // Don't send default credentials to any of these zones case SecurityZone.Internet: case SecurityZone.Untrusted: default: return !IsDefaultCredentials(credential); } } #endregion ////// Critical - Asserts for permission to examine the user name and password. They are /// only checked to see if they are non-null, and not exposed, but the /// fact that default credential are being used and are available might /// something we would not want revealed, which is why it is not TAS. /// [SecurityCritical] private bool IsDefaultCredentials(NetworkCredential credential) { _environmentPermissionSet.Assert(); // BlessedAssert: try { return credential == CredentialCache.DefaultCredentials; } finally { CodeAccessPermission.RevertAssert(); } } ////// Critical - Call critical method MapUrlToZone. /// TreatAsSafe - Returns the zone of the uri, which is not critical. /// [SecurityCritical, SecurityTreatAsSafe] internal static SecurityZone MapUrlToZone(Uri uri) { EnsureSecurityManager(); int targetZone; _securityManager.MapUrlToZone(BindUriHelper.UriToString(uri), out targetZone, 0); // The enum is directly mappable, but taking no chances... switch (targetZone) { case NativeMethods.URLZONE_LOCAL_MACHINE: return SecurityZone.MyComputer; case NativeMethods.URLZONE_INTERNET: return SecurityZone.Internet; case NativeMethods.URLZONE_INTRANET: return SecurityZone.Intranet; case NativeMethods.URLZONE_TRUSTED: return SecurityZone.Trusted; case NativeMethods.URLZONE_UNTRUSTED: return SecurityZone.Untrusted; } return SecurityZone.NoZone; } ////// Critical - Accesses critical member _securityManager and calls the SUC'd MapUrlToZone. /// TreatAsSafe - Doesn't expose anything, doesn't take user input, safe to call at any time. /// [SecurityCritical, SecurityTreatAsSafe] private static void EnsureSecurityManager() { // IMPORTANT: See comments in header r.e. IInternetSecurityManager if (_securityManager == null) { lock (_lockObj) { if (_securityManager == null) { _securityManager = (UnsafeNativeMethods.IInternetSecurityManager)new InternetSecurityManager(); } } } } [ComImport, ComVisible(false), Guid("7b8a2d94-0ac9-11d1-896c-00c04Fb6bfc4")] private class InternetSecurityManager { } ////// Critical - requires an elevation to create. /// [SecurityCritical] private static UnsafeNativeMethods.IInternetSecurityManager _securityManager; [SecurityCritical] private static object _lockObj; [SecurityCritical] private static bool _initialized; [SecurityCritical] PermissionSet _environmentPermissionSet; } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.
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