helper.cxx

这是国外的resip协议栈

#if defined(USE_SSL)
#include <openssl/blowfish.h>

static const Data sep("[]");
static const Data pad("\0\0\0\0\0\0\0", 7);
static const Data GRUU("_GRUU");
static const int saltBytes(16);

Data
Helper::gruuUserPart(const Data& instanceId,
                     const Data& aor,
                     const Data& key)
{
   unsigned char ivec[8];      

   ivec[0] = '\x6E';
   ivec[1] = '\xE7';
   ivec[2] = '\xB0';
   ivec[3] = '\x4A';
   ivec[4] = '\x45';
   ivec[5] = '\x93';
   ivec[6] = '\x7D';
   ivec[7] = '\x51';

   BF_KEY fish;
   BF_set_key(&fish, key.size(), (const unsigned char*)key.data());

   const Data salt(resip::Random::getRandomHex(saltBytes));

   const Data token(salt + instanceId + sep + aor + '\0' +
                    pad.substr(0, (8 - ((salt.size() + 
                                         instanceId.size() + 
                                         sep.size() + 1 
                                         + aor.size() ) % 8))
                               % 8));
   auto_ptr <unsigned char> out(new unsigned char[token.size()]);
   BF_cbc_encrypt((const unsigned char*)token.data(),
                  out.get(),
                  token.size(),
                  &fish,
                  ivec, 
                  BF_ENCRYPT);

   return GRUU + Data(out.get(),token.size()).base64encode(true/*safe URL*/);
}

std::pair<Data,Data> 
Helper::fromGruuUserPart(const Data& gruuUserPart,
                         const Data& key)
{
   unsigned char ivec[8];      

   ivec[0] = '\x6E';
   ivec[1] = '\xE7';
   ivec[2] = '\xB0';
   ivec[3] = '\x4A';
   ivec[4] = '\x45';
   ivec[5] = '\x93';
   ivec[6] = '\x7D';
   ivec[7] = '\x51';

   static const std::pair<Data, Data> empty;

   if (gruuUserPart.size() < GRUU.size())
   {
      return empty;
   }

   const Data gruu = gruuUserPart.substr(GRUU.size());

   BF_KEY fish;
   BF_set_key(&fish, key.size(), (const unsigned char*)key.data());

   const Data decoded = gruu.base64decode();

   auto_ptr <unsigned char> out(new unsigned char[gruuUserPart.size()+1]);
   BF_cbc_encrypt((const unsigned char*)decoded.data(),
                  out.get(),
                  decoded.size(),
                  &fish,
                  ivec, 
                  BF_DECRYPT);
   const Data pair(out.get(), decoded.size());

   Data::size_type pos = pair.find(sep);
   if (pos == Data::npos)
   {
      return empty;
   }

   return std::make_pair(pair.substr(2*saltBytes, pos), // strip out the salt
                         pair.substr(pos+sep.size()));
}
#endif
Helper::ContentsSecAttrs::ContentsSecAttrs()
   : mContents(0),
     mAttributes(0)
{}

Helper::ContentsSecAttrs::ContentsSecAttrs(std::auto_ptr<Contents> contents,
                                           std::auto_ptr<SecurityAttributes> attributes)
   : mContents(contents),
     mAttributes(attributes)
{}

Helper::ContentsSecAttrs::ContentsSecAttrs(const ContentsSecAttrs& rhs)
   : mContents(rhs.mContents),
     mAttributes(rhs.mAttributes)
{}

Helper::ContentsSecAttrs& 
Helper::ContentsSecAttrs::operator=(const ContentsSecAttrs& rhs)
{
   if (&rhs != this)
   {
      mContents = rhs.mContents;
      mAttributes = rhs.mAttributes;
   }
   return *this;
}


Contents*
extractFromPkcs7Recurse(Contents* tree,
                        const Data& signerAor,
                        const Data& receiverAor,
                        SecurityAttributes* attributes,
                        Security& security)
{
   Pkcs7Contents* pk;
   if ((pk = dynamic_cast<Pkcs7Contents*>(tree)))
   {
      InfoLog( << "GREG1: " << *pk );
#if defined(USE_SSL)
      Contents* contents = security.decrypt(receiverAor, pk);
      if (contents)
      {
         attributes->setEncrypted();
      }
      return contents;
#else
      return 0;
#endif
   }
   MultipartSignedContents* mps;
   if ((mps = dynamic_cast<MultipartSignedContents*>(tree)))
   {
      InfoLog( << "GREG2: " << *mps );
#if defined(USE_SSL)
      Data signer;
      SignatureStatus sigStatus;
      Contents* b = extractFromPkcs7Recurse(security.checkSignature(mps, 
                                                                    &signer,
                                                                    &sigStatus),
                                            signerAor,
                                            receiverAor, attributes, security);
      attributes->setSigner(signer);
      attributes->setSignatureStatus(sigStatus);
      return b->clone();
#else
      return mps->parts().front()->clone();
#endif      
   }
   MultipartAlternativeContents* alt;
   if ((alt = dynamic_cast<MultipartAlternativeContents*>(tree)))
   {
      InfoLog( << "GREG3: " << *alt );
      for (MultipartAlternativeContents::Parts::reverse_iterator i = alt->parts().rbegin();
           i != alt->parts().rend(); ++i)
      {
         Contents* b = extractFromPkcs7Recurse(*i, signerAor, receiverAor, attributes, security);
         if (b)
         {
            return b;
         }
      }
   }

   MultipartMixedContents* mult;
   if ((mult = dynamic_cast<MultipartMixedContents*>(tree)))
   {
      InfoLog( << "GREG4: " << *mult );
      for (MultipartMixedContents::Parts::iterator i = mult->parts().begin();
           i != mult->parts().end(); ++i)
      {
         Contents* b = extractFromPkcs7Recurse(*i, signerAor, receiverAor,
                                               attributes, security);
         if (b)
         {
            return b;
         }
      };

      return 0;
   }

   return tree->clone();
}

Helper::ContentsSecAttrs
Helper::extractFromPkcs7(const SipMessage& message, 
                         Security& security)
{
   SecurityAttributes* attr = new SecurityAttributes;
   // .dlb. currently flattening SecurityAttributes?
   //attr->setIdentity(message.getIdentity());
   attr->setIdentity(message.header(h_From).uri().getAor());
   Contents *b = message.getContents();
   if (b) 
   {
      Data fromAor(message.header(h_From).uri().getAor());
      Data toAor(message.header(h_To).uri().getAor());
      if (message.isRequest())
      {
         b = extractFromPkcs7Recurse(b, fromAor, toAor, attr, security);
      }
      else // its a response
      {
         b = extractFromPkcs7Recurse(b, toAor, fromAor, attr, security);
      }
   }
   std::auto_ptr<Contents> c(b);
   std::auto_ptr<SecurityAttributes> a(attr);
   return ContentsSecAttrs(c, a);
}

Helper::FailureMessageEffect 
Helper::determineFailureMessageEffect(const SipMessage& response)
{
   assert(response.isResponse());
   int code = response.header(h_StatusLine).statusCode();
   assert(code >= 400);
   
   switch(code)
   {
      case 404:
      case 410:
      case 416:
      case 480:  // but maybe not, still not quite decided:
      case 481:
      case 482: // but maybe not, still not quite decided:
      case 484:
      case 485:
      case 502:
      case 604:
         return DialogTermination;
      case 403:
      case 489: //only for only subscription
      case 408:  //again, maybe not. This seems best.
         return UsageTermination;      
      case 400:
      case 401:
      case 402:
      case 405:  //doesn't agree w/  -00 of dialogusage
      case 406:
      case 412:
      case 413:
      case 414:
      case 415:
      case 420:
      case 421:
      case 423:

      case 429: // but if this the refer creating the Subscription, no sub will be created.
      case 486:
      case 487:
      case 488:
      case 491: 
      case 493:
      case 494:
      case 505:
      case 513:
      case 603:
      case 606:
         return TransactionTermination;
      case 483: // who knows, gravefully terminate or just destroy dialog
      case 501:
         return ApplicationDependant;
      default:
         if (code < 600)
         {
            if (response.exists(h_RetryAfter))

            {
               return RetryAfter;
            }
            else
            {
               return OptionalRetryAfter;
            }
         }
         else
         {
            if (response.exists(h_RetryAfter))
            {
               return RetryAfter;
            }
            else
            {
               return ApplicationDependant;
            }
         }
   }
}

SdpContents* getSdpRecurse(Contents* tree)
{
   if (dynamic_cast<SdpContents*>(tree))
   {
      return static_cast<SdpContents*>(tree);
   }

   MultipartSignedContents* mps;
   if ((mps = dynamic_cast<MultipartSignedContents*>(tree)))
   {
      try
      {
         MultipartSignedContents::Parts::const_iterator it = mps->parts().begin();
         Contents* contents = getSdpRecurse(*it);
         return static_cast<SdpContents*>(contents);
      }
      catch (ParseException& e)
      {
         ErrLog(<< e.name() << endl << e.getMessage());       
      }
      catch (BaseException& e)
      {
         ErrLog(<< e.name() << endl << e.getMessage());
      }

      return 0;
   }

   MultipartAlternativeContents* alt;
   if ((alt = dynamic_cast<MultipartAlternativeContents*>(tree)))
   {
      try
      {
         for (MultipartAlternativeContents::Parts::reverse_iterator i = alt->parts().rbegin();
              i != alt->parts().rend(); ++i)
         {
            Contents* contents = getSdpRecurse(*i);
            if (contents)
            {
               return static_cast<SdpContents*>(contents);
            }
         }
      }
      catch (ParseException& e)
      {
         ErrLog(<< e.name() << endl << e.getMessage());
      }
      catch (BaseException& e)
      {
         ErrLog(<< e.name() << endl << e.getMessage());
      }

      return 0;
   }

   MultipartMixedContents* mult;
   if ((mult = dynamic_cast<MultipartMixedContents*>(tree)))
   {

      try
      {
         for (MultipartMixedContents::Parts::iterator i = mult->parts().begin();
              i != mult->parts().end(); ++i)
         {
            Contents* contents = getSdpRecurse(*i);
            if (contents)
            {
               return static_cast<SdpContents*>(contents);
            }
         }
      }
      catch (ParseException& e)
      {
         ErrLog(<< e.name() << endl << e.getMessage());
      }
      catch (BaseException& e)
      {
         ErrLog(<< e.name() << endl << e.getMessage());
      }

      return 0;
   }

   return 0;
}

auto_ptr<SdpContents> Helper::getSdp(Contents* tree)
{
   static std::auto_ptr<SdpContents> empty;

   if (tree) 
   {
      SdpContents* sdp = getSdpRecurse(tree);

      if (sdp)
      {
         DebugLog(<< "Got sdp" << endl);
         return auto_ptr<SdpContents>(static_cast<SdpContents*>(sdp->clone()));
      }
   }

   //DebugLog(<< "No sdp" << endl);
   return empty;
}


/* ====================================================================
 * The Vovida Software License, Version 1.0 
 * 
 * Copyright (c) 2000 Vovida Networks, Inc.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *