parse.cpp

含有多种公开密钥算法、多种块加密、多种数据流加密、多种HASH函数、多种CheckSum校验、多种MAC校验等几十种加密算法的程序

/*************************************************
* Parsing Functions Source File                  *
* (C) 1999-2002 The Botan Project                *
*************************************************/

#include <botan/util.h>
#include <botan/exceptn.h>

namespace Botan {

/*************************************************
* Parse a SCAN-style algorithm name              *
*************************************************/
std::vector<std::string> parse_algorithm_name(const std::string& namex)
   {
   if(namex.find('(') == std::string::npos &&
      namex.find(')') == std::string::npos)
      return std::vector<std::string>(1, namex);

   std::string name = namex, substring;
   std::vector<std::string> elems;
   std::string::const_iterator i;
   u32bit level = 0;

   elems.push_back(name.substr(0, name.find('(')));
   name = name.substr(name.find('('));

   for(i = name.begin(); i != name.end(); i++)
      {
      char c = *i;

      if(c == '(')
         level++;
      if(c == ')')
         {
         if(level == 1 && i == name.end() - 1)
            {
            if(elems.size() == 1)
               elems.push_back(substring.substr(1));
            else
               elems.push_back(substring);
            return elems;
            }

         if(level == 0 || (level == 1 && i != name.end() - 1))
            throw Invalid_Algorithm_Name(namex);
         level--;
         }

      if(c == ',' && level == 1)
         {
         if(elems.size() == 1)
            elems.push_back(substring.substr(1));
         else
            elems.push_back(substring);
         substring = "";
         }
      else
         substring += c;
      }

   if(substring != "")
      throw Invalid_Algorithm_Name(namex);

   return elems;
   }

}