/*
    * MIT License
    *
    * Copyright (c) 2010-2024 The Waffle Project Contributors: https://github.com/Waffle/waffle/graphs/contributors
    *
    * Permission is hereby granted, free of charge, to any person obtaining a copy
    * of this software and associated documentation files (the "Software"), to deal
    * in the Software without restriction, including without limitation the rights
    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  package waffle.windows.auth.impl;
  
  import com.sun.jna.platform.win32.Secur32;
  import com.sun.jna.platform.win32.Sspi;
  import com.sun.jna.platform.win32.Sspi.CtxtHandle;
  import com.sun.jna.platform.win32.Sspi.SecBufferDesc;
  import com.sun.jna.platform.win32.SspiUtil.ManagedSecBufferDesc;
  import com.sun.jna.platform.win32.Win32Exception;
  import com.sun.jna.platform.win32.WinError;
  import com.sun.jna.platform.win32.WinNT.HANDLEByReference;
  import com.sun.jna.ptr.IntByReference;
  
  import waffle.windows.auth.IWindowsCredentialsHandle;
  import waffle.windows.auth.IWindowsIdentity;
  import waffle.windows.auth.IWindowsImpersonationContext;
  import waffle.windows.auth.IWindowsSecurityContext;
  
  /**
   * Windows Security Context.
   */
  public class WindowsSecurityContextImpl implements IWindowsSecurityContext {
  
      /** The principal name. */
      private String principalName;
  
      /** The security package. */
      private String securityPackage;
  
      /** The token. */
      private ManagedSecBufferDesc token;
  
      /** The ctx. */
      private CtxtHandle ctx;
  
      /** The credentials. */
      private IWindowsCredentialsHandle credentials;
  
      /** The continue flag. */
      private boolean continueFlag;
  
      @Override
      public IWindowsImpersonationContext impersonate() {
          return new WindowsSecurityContextImpersonationContextImpl(this.ctx);
      }
  
      @Override
      public IWindowsIdentity getIdentity() {
          final HANDLEByReference phContextToken = new HANDLEByReference();
          final int rc = Secur32.INSTANCE.QuerySecurityContextToken(this.ctx, phContextToken);
          if (WinError.SEC_E_OK != rc) {
              throw new Win32Exception(rc);
          }
          return new WindowsIdentityImpl(phContextToken.getValue());
      }
  
      @Override
      public String getSecurityPackage() {
          return this.securityPackage;
      }
  
      @Override
      public byte[] getToken() {
          return this.token == null || this.token.getBuffer(0).getBytes() == null ? null
                  : this.token.getBuffer(0).getBytes().clone();
      }
  
      /**
       * Get the current Windows security context for a given SSPI package.
       *
       * @param securityPackage
       *            SSPI package.
       * @param targetName
       *            The target of the context. The string contents are security-package specific.
       *
       * @return Windows security context.
       */
     public static IWindowsSecurityContext getCurrent(final String securityPackage, final String targetName) {
         IWindowsCredentialsHandle credentialsHandle = WindowsCredentialsHandleImpl.getCurrent(securityPackage);
         credentialsHandle.initialize();
         try {
             final WindowsSecurityContextImpl ctx = new WindowsSecurityContextImpl();
             ctx.setPrincipalName(WindowsAccountImpl.getCurrentUsername());
             ctx.setCredentialsHandle(credentialsHandle);
             ctx.setSecurityPackage(securityPackage);
             ctx.initialize(null, null, targetName);
 
             // Starting from here ctx 'owns' the credentials handle, so let's null out the
             // variable. This will prevent the finally block below from disposing it right away.
             credentialsHandle = null;
 
             return ctx;
         } finally {
             if (credentialsHandle != null) {
                 credentialsHandle.dispose();
             }
         }
     }
 
     @Override
     public void initialize(final CtxtHandle continueCtx, final SecBufferDesc continueToken, final String targetName) {
         final IntByReference attr = new IntByReference();
         this.ctx = new CtxtHandle();
         int tokenSize = Sspi.MAX_TOKEN_SIZE;
         int rc;
         do {
             this.token = new ManagedSecBufferDesc(Sspi.SECBUFFER_TOKEN, tokenSize);
             rc = Secur32.INSTANCE.InitializeSecurityContext(this.credentials.getHandle(), continueCtx, targetName,
                     Sspi.ISC_REQ_CONNECTION, 0, Sspi.SECURITY_NATIVE_DREP, continueToken, 0, this.ctx, this.token, attr,
                     null);
             switch (rc) {
                 case WinError.SEC_E_INSUFFICIENT_MEMORY:
                 case WinError.SEC_E_BUFFER_TOO_SMALL:
                     tokenSize += Sspi.MAX_TOKEN_SIZE;
                     break;
                 case WinError.SEC_I_CONTINUE_NEEDED:
                     this.continueFlag = true;
                     break;
                 case WinError.SEC_E_OK:
                     this.continueFlag = false;
                     break;
                 default:
                     throw new Win32Exception(rc);
             }
         } while (rc == WinError.SEC_E_INSUFFICIENT_MEMORY || rc == WinError.SEC_E_BUFFER_TOO_SMALL);
     }
 
     @Override
     public void dispose() {
         WindowsSecurityContextImpl.dispose(this.ctx);
 
         if (this.credentials != null) {
             this.credentials.dispose();
         }
     }
 
     /**
      * Dispose a security context.
      *
      * @param ctx
      *            Security context.
      *
      * @return True if a context was disposed.
      */
     public static boolean dispose(final CtxtHandle ctx) {
         if (ctx != null && !ctx.isNull()) {
             final int rc = Secur32.INSTANCE.DeleteSecurityContext(ctx);
             if (WinError.SEC_E_OK != rc) {
                 throw new Win32Exception(rc);
             }
             return true;
         }
         return false;
     }
 
     @Override
     public String getPrincipalName() {
         return this.principalName;
     }
 
     /**
      * Sets the principal name.
      *
      * @param value
      *            the new principal name
      */
     public void setPrincipalName(final String value) {
         this.principalName = value;
     }
 
     @Override
     public CtxtHandle getHandle() {
         return this.ctx;
     }
 
     /**
      * Sets the credentials handle.
      *
      * @param handle
      *            the new credentials handle
      */
     public void setCredentialsHandle(final IWindowsCredentialsHandle handle) {
         this.credentials = handle;
     }
 
     /**
      * Sets the token.
      *
      * @param bytes
      *            the new token
      */
     public void setToken(final byte[] bytes) {
         this.token = new ManagedSecBufferDesc(Sspi.SECBUFFER_TOKEN, bytes);
     }
 
     /**
      * Sets the security package.
      *
      * @param value
      *            the new security package
      */
     public void setSecurityPackage(final String value) {
         this.securityPackage = value;
     }
 
     /**
      * Sets the security context.
      *
      * @param phNewServerContext
      *            the new security context
      */
     public void setSecurityContext(final CtxtHandle phNewServerContext) {
         this.ctx = phNewServerContext;
     }
 
     @Override
     public boolean isContinue() {
         return this.continueFlag;
     }
 
     /**
      * Sets the continue.
      *
      * @param b
      *            the new continue
      */
     public void setContinue(final boolean b) {
         this.continueFlag = b;
     }
 
 }