/*
* X509_DN
* (C) 1999-2007,2018 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include <botan/x509_dn.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/parsing.h>
#include <botan/internal/stl_util.h>
#include <botan/oids.h>
#include <ostream>
#include <sstream>
#include <cctype>

namespace Botan {

/*
* Add an attribute to a X509_DN
*/
void X509_DN::add_attribute(const std::string& type,
                            const std::string& str)
   {
   add_attribute(OIDS::lookup(type), str);
   }

/*
* Add an attribute to a X509_DN
*/
void X509_DN::add_attribute(const OID& oid, const ASN1_String& str)
   {
   if(str.empty())
      return;

   m_rdn.push_back(std::make_pair(oid, str));
   m_dn_bits.clear();
   }

/*
* Get the attributes of this X509_DN
*/
std::multimap<OID, std::string> X509_DN::get_attributes() const
   {
   std::multimap<OID, std::string> retval;

   for(auto& i : m_rdn)
      multimap_insert(retval, i.first, i.second.value());
   return retval;
   }

/*
* Get the contents of this X.500 Name
*/
std::multimap<std::string, std::string> X509_DN::contents() const
   {
   std::multimap<std::string, std::string> retval;

   for(auto& i : m_rdn)
      {
      std::string str_value = OIDS::oid2str(i.first);

      if(str_value.empty())
         str_value = i.first.to_string();
      multimap_insert(retval, str_value, i.second.value());
      }
   return retval;
   }

bool X509_DN::has_field(const std::string& attr) const
   {
   return has_field(OIDS::lookup(deref_info_field(attr)));
   }

bool X509_DN::has_field(const OID& oid) const
   {
   for(auto& i : m_rdn)
      {
      if(i.first == oid)
         return true;
      }

   return false;
   }

std::string X509_DN::get_first_attribute(const std::string& attr) const
   {
   const OID oid = OIDS::lookup(deref_info_field(attr));
   return get_first_attribute(oid).value();
   }

ASN1_String X509_DN::get_first_attribute(const OID& oid) const
   {
   for(auto& i : m_rdn)
      {
      if(i.first == oid)
         {
         return i.second;
         }
      }

   return ASN1_String();
   }

/*
* Get a single attribute type
*/
std::vector<std::string> X509_DN::get_attribute(const std::string& attr) const
   {
   const OID oid = OIDS::lookup(deref_info_field(attr));

   std::vector<std::string> values;

   for(auto& i : m_rdn)
      {
      if(i.first == oid)
         {
         values.push_back(i.second.value());
         }
      }

   return values;
   }

/*
* Deref aliases in a subject/issuer info request
*/
std::string X509_DN::deref_info_field(const std::string& info)
   {
   if(info == "Name" || info == "CommonName" || info == "CN") return "X520.CommonName";
   if(info == "SerialNumber" || info == "SN")                 return "X520.SerialNumber";
   if(info == "Country" || info == "C")                       return "X520.Country";
   if(info == "Organization" || info == "O")                  return "X520.Organization";
   if(info == "Organizational Unit" || info == "OrgUnit" || info == "OU")
      return "X520.OrganizationalUnit";
   if(info == "Locality" || info == "L")                      return "X520.Locality";
   if(info == "State" || info == "Province" || info == "ST")  return "X520.State";
   if(info == "Email")                                        return "RFC822";
   return info;
   }

/*
* Compare two X509_DNs for equality
*/
bool operator==(const X509_DN& dn1, const X509_DN& dn2)
   {
   auto attr1 = dn1.get_attributes();
   auto attr2 = dn2.get_attributes();

   if(attr1.size() != attr2.size()) return false;

   auto p1 = attr1.begin();
   auto p2 = attr2.begin();

   while(true)
      {
      if(p1 == attr1.end() && p2 == attr2.end())
         break;
      if(p1 == attr1.end())      return false;
      if(p2 == attr2.end())      return false;
      if(p1->first != p2->first) return false;
      if(!x500_name_cmp(p1->second, p2->second))
         return false;
      ++p1;
      ++p2;
      }
   return true;
   }

/*
* Compare two X509_DNs for inequality
*/
bool operator!=(const X509_DN& dn1, const X509_DN& dn2)
   {
   return !(dn1 == dn2);
   }

/*
* Induce an arbitrary ordering on DNs
*/
bool operator<(const X509_DN& dn1, const X509_DN& dn2)
   {
   auto attr1 = dn1.get_attributes();
   auto attr2 = dn2.get_attributes();

   // If they are not the same size, choose the smaller as the "lessor"
   if(attr1.size() < attr2.size())
      return true;
   if(attr1.size() > attr2.size())
      return false;

   // We know they are the same # of elements, now compare the OIDs:
   auto p1 = attr1.begin();
   auto p2 = attr2.begin();

   while(p1 != attr1.end() && p2 != attr2.end())
      {
      if(p1->first != p2->first)
         {
         return (p1->first < p2->first);
         }

      ++p1;
      ++p2;
      }

   // We know this is true because maps have the same size
   BOTAN_ASSERT_NOMSG(p1 == attr1.end());
   BOTAN_ASSERT_NOMSG(p2 == attr2.end());

   // Now we know all elements have the same OIDs, compare
   // their string values:

   p1 = attr1.begin();
   p2 = attr2.begin();
   while(p1 != attr1.end() && p2 != attr2.end())
      {
      BOTAN_DEBUG_ASSERT(p1->first == p2->first);

      // They may be binary different but same by X.500 rules, check this
      if(!x500_name_cmp(p1->second, p2->second))
         {
         // If they are not (by X.500) the same string, pick the
         // lexicographic first as the lessor
         return (p1->second < p2->second);
         }

      ++p1;
      ++p2;
      }

   // if we reach here, then the DNs should be identical
   BOTAN_DEBUG_ASSERT(dn1 == dn2);
   return false;
   }

/*
* DER encode a DistinguishedName
*/
void X509_DN::encode_into(DER_Encoder& der) const
   {
   der.start_cons(SEQUENCE);

   if(!m_dn_bits.empty())
      {
      /*
      If we decoded this from somewhere, encode it back exactly as
      we received it
      */
      der.raw_bytes(m_dn_bits);
      }
   else
      {
      for(const auto& dn : m_rdn)
         {
         der.start_cons(SET)
            .start_cons(SEQUENCE)
            .encode(dn.first)
            .encode(dn.second)
            .end_cons()
         .end_cons();
         }
      }

   der.end_cons();
   }

/*
* Decode a BER encoded DistinguishedName
*/
void X509_DN::decode_from(BER_Decoder& source)
   {
   std::vector<uint8_t> bits;

   source.start_cons(SEQUENCE)
      .raw_bytes(bits)
   .end_cons();

   BER_Decoder sequence(bits);

   while(sequence.more_items())
      {
      BER_Decoder rdn = sequence.start_cons(SET);

      while(rdn.more_items())
         {
         OID oid;
         ASN1_String str;

         rdn.start_cons(SEQUENCE)
            .decode(oid)
            .decode(str) // TODO support Any
            .end_cons().verify_end("Invalid X509_DN, data follows RDN");

         add_attribute(oid, str);
         }
      }

   m_dn_bits = bits;
   }

namespace {

std::string to_short_form(const OID& oid)
   {
   const std::string long_id = OIDS::oid2str(oid);

   if(long_id.empty())
      return oid.to_string();

   if(long_id == "X520.CommonName")
      return "CN";

   if(long_id == "X520.Country")
      return "C";

   if(long_id == "X520.Organization")
      return "O";

   if(long_id == "X520.OrganizationalUnit")
      return "OU";

   return long_id;
   }

}

std::string X509_DN::to_string() const
   {
   std::ostringstream out;
   out << *this;
   return out.str();
   }

std::ostream& operator<<(std::ostream& out, const X509_DN& dn)
   {
   auto info = dn.dn_info();

   for(size_t i = 0; i != info.size(); ++i)
      {
      out << to_short_form(info[i].first) << "=\"";
      for(char c : info[i].second.value())
         {
         if(c == '\\' || c == '\"')
            {
            out << "\\";
            }
         out << c;
         }
      out << "\"";

      if(i + 1 < info.size())
         {
         out << ",";
         }
      }
   return out;
   }

std::istream& operator>>(std::istream& in, X509_DN& dn)
   {
   in >> std::noskipws;
   do
      {
      std::string key;
      std::string val;
      char c;

      while(in.good())
         {
         in >> c;

         if(std::isspace(c) && key.empty())
            continue;
         else if(!std::isspace(c))
            {
            key.push_back(c);
            break;
            }
         else
            break;
         }

      while(in.good())
         {
         in >> c;

         if(!std::isspace(c) && c != '=')
            key.push_back(c);
         else if(c == '=')
            break;
         else
            throw Invalid_Argument("Ill-formed X.509 DN");
         }

      bool in_quotes = false;
      while(in.good())
         {
         in >> c;

         if(std::isspace(c))
            {
            if(!in_quotes && !val.empty())
               break;
            else if(in_quotes)
               val.push_back(' ');
            }
         else if(c == '"')
            in_quotes = !in_quotes;
         else if(c == '\\')
            {
            if(in.good())
               in >> c;
            val.push_back(c);
            }
         else if(c == ',' && !in_quotes)
            break;
         else
            val.push_back(c);
         }

      if(!key.empty() && !val.empty())
         dn.add_attribute(X509_DN::deref_info_field(key),val);
      else
         break;
      }
   while(in.good());
   return in;
   }
}