/*
    * 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.util;
  
  import java.util.Base64;
  import java.util.Locale;
  
  import javax.servlet.http.HttpServletRequest;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Authorization header.
   */
  public class AuthorizationHeader {
  
      /** The logger. */
      private static final Logger LOGGER = LoggerFactory.getLogger(AuthorizationHeader.class);
  
      /** The request. */
      private final HttpServletRequest request;
  
      /**
       * Instantiates a new authorization header.
       *
       * @param httpServletRequest
       *            the http servlet request
       */
      public AuthorizationHeader(final HttpServletRequest httpServletRequest) {
          this.request = httpServletRequest;
      }
  
      /**
       * Gets the header.
       *
       * @return the header
       */
      public String getHeader() {
          return this.request.getHeader("Authorization");
      }
  
      /**
       * Checks if is null.
       *
       * @return true, if is null
       */
      public boolean isNull() {
          return this.getHeader() == null || this.getHeader().length() == 0;
      }
  
      /**
       * Returns a supported security package string.
       *
       * <pre>
       * Authorization: NTLM the_token
       * Authorization: Negotiate the_token
       * Authorization: Bearer the_token
       * </pre>
       *
       * @return AuthenticationScheme as SecurityPackage e.g. Negotiate, NTLM, Bearer.
       */
      public String getSecurityPackage() {
          final String header = this.getHeader();
  
          if (header == null) {
              throw new RuntimeException("Missing Authorization: header");
          }
  
          final int space = header.indexOf(' ');
          if (space > 0) {
              return header.substring(0, space);
          }
  
          throw new RuntimeException("Invalid Authorization header: " + header);
      }
  
      @Override
     public String toString() {
         return this.isNull() ? "<none>" : this.getHeader();
     }
 
     /**
      * Gets the token.
      *
      * @return the token
      */
     public String getToken() {
         return this.getHeader().substring(this.getSecurityPackage().length() + 1);
     }
 
     /**
      * Gets the token bytes.
      *
      * @return the token bytes
      */
     public byte[] getTokenBytes() {
         try {
             return Base64.getDecoder().decode(this.getToken());
         } catch (final IllegalArgumentException e) {
             AuthorizationHeader.LOGGER.debug("", e);
             throw new RuntimeException("Invalid authorization header.");
         }
     }
 
     /**
      * Checks if is ntlm type1 message.
      *
      * @return true, if is ntlm type1 message
      */
     public boolean isNtlmType1Message() {
         if (this.isNull()) {
             return false;
         }
 
         final byte[] tokenBytes = this.getTokenBytes();
         if (!NtlmMessage.isNtlmMessage(tokenBytes)) {
             return false;
         }
 
         return 1 == NtlmMessage.getMessageType(tokenBytes);
     }
 
     /**
      * Checks if is SP nego message.
      *
      * @return true, if is SP nego message that contains NegTokenInit
      */
     public boolean isSPNegTokenInitMessage() {
 
         if (this.isNull()) {
             return false;
         }
 
         final byte[] tokenBytes = this.getTokenBytes();
         return SPNegoMessage.isNegTokenInit(tokenBytes);
     }
 
     /**
      * When using NTLM authentication and the browser is making a POST request, it preemptively sends a Type 2
      * authentication message (without the POSTed data). The server responds with a 401, and the browser sends a Type 3
      * request with the POSTed data. This is to avoid the situation where user's credentials might be potentially
      * invalid, and all this data is being POSTed across the wire.
      *
      * @return True if request is an NTLM POST, PUT, or DELETE with an Authorization header and no data.
      */
     public boolean isNtlmType1PostAuthorizationHeader() {
         if (!"POST".equals(this.request.getMethod()) && !"PUT".equals(this.request.getMethod())
                 && !"DELETE".equals(this.request.getMethod())) {
             return false;
         }
 
         if (this.request.getContentLength() != 0) {
             return false;
         }
 
         return this.isNtlmType1Message() || this.isSPNegTokenInitMessage();
     }
 
     /**
      * Is Bearer Authorization Header will return true if 'BEARER' exists.
      *
      * @return True if header contains 'BEARER' header.
      */
     public boolean isBearerAuthorizationHeader() {
         if (this.isNull()) {
             return false;
         }
 
         return this.getSecurityPackage().toUpperCase(Locale.ENGLISH).equalsIgnoreCase("BEARER");
     }
 }