/*

 * lftp - file transfer program

 *

 * Copyright (c) 2016 by Alexander V. Lukyanov (lav@yars.free.net)

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

#ifndef HTTPAUTH_H

#define HTTPAUTH_H

#include "xmap.h"

#include "xarray.h"

#include "HttpHeader.h"

class HttpAuth

{

public:

   enum target_t { WWW=0, PROXY };

   enum scheme_t { NONE=0, BASIC, DIGEST };

   class Challenge

   {

      scheme_t scheme_code;

      xstring scheme;

      xmap_p<xstring> param;

      void SetParam(const char *p,int p_len,const xstring &v) {

	 param.add(xstring::get_tmp(p,p_len).c_lc(),new xstring(v.copy()));

      }

      void SetParam(const xstring &p,const xstring &v) {

	 param.add(p,new xstring(v.copy()));

      }

   public:

      Challenge(const char *);

      const xstring& GetScheme() { return scheme; }

      scheme_t GetSchemeCode() { return scheme_code; }

      const xstring& GetRealm() { return GetParam("realm"); }

      const xstring& GetParam(const char *p) {

	 const xstring *v=param.lookup(p);

	 return v?*v:xstring::null;

      }

   };

protected:

   target_t target;

   xstring uri;

   Ref<Challenge> chal;

   xstring user;

   xstring pass;

   HttpHeader header;

   static xstring& append_quoted(xstring& s,const char *n,const char *v);

   // array is enough as there are not too many HttpAuth objects.

   static xarray_p<HttpAuth> cache;

public:

   HttpAuth(target_t t,const char *p_uri,Challenge *p_chal,const char *p_user,const char *p_pass)

      :  target(t), uri(p_uri), chal(p_chal), user(p_user), pass(p_pass),

	 header(t==WWW?"Authorization":"Proxy-Authorization") {}

   virtual ~HttpAuth() {}

   virtual bool IsValid() const { return true; }

   virtual bool Update(const char *p_method,const char *p_uri,const char *entity_hash=0) { return true; }

   const HttpHeader *GetHeader() { return &header; }

   bool ApplicableForURI(const char *) const;

   bool Matches(target_t t,const char *p_uri,const char *p_user);

   static bool New(target_t t,const char *p_uri,

      Challenge *p_chal,const char *p_user,const char *p_pass);

   static HttpAuth *Get(target_t t,const char *p_uri,const char *p_user);

   static void CleanCache(target_t t,const char *p_uri,const char *p_user);

};

class HttpAuthBasic : public HttpAuth

{

   void MakeHeader();

public:

   HttpAuthBasic(target_t t,const char *p_uri,Challenge *p_chal,const char *p_user,const char *p_pass)

      :  HttpAuth(t,p_uri,p_chal,p_user,p_pass) { MakeHeader(); }

};

class HttpAuthDigest : public HttpAuth

{

   xstring cnonce;   // random client nonce

   xstring HA1;	     // "session key" A1 in lower-case hex

   unsigned nc;

   void MakeHA1();

public:

   HttpAuthDigest(target_t t,const char *p_uri,Challenge *p_chal,const char *p_user,const char *p_pass)

      :  HttpAuth(t,p_uri,p_chal,p_user,p_pass), nc(0) { MakeHA1(); }

   bool IsValid() const { return HA1.length()>0; }

   bool Update(const char *p_method,const char *p_uri,const char *entity_hash);

};

#endif//HTTPAUTH_H