/*=========================================================================

  Program: GDCM (Grassroots DICOM). A DICOM library

  Copyright (c) 2006-2011 Mathieu Malaterre
  All rights reserved.
  See Copyright.txt or http://gdcm.sourceforge.net/Copyright.html for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "gdcmASN1.h"
#include "gdcmSystem.h"

#include <cstring>

#ifdef GDCM_USE_SYSTEM_OPENSSL
#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/pem.h>
#include <openssl/rand.h>
#include <openssl/x509.h>
#endif

#include <fstream>

/*
 */
namespace gdcm
{

class ASN1Internals
{
public:
};

ASN1::ASN1()
{
  Internals = new ASN1Internals;
}

ASN1::~ASN1()
{
  delete Internals;
}

bool ASN1::ParseDumpFile(const char *filename)
{
  if(!filename) return false;
  std::ifstream is(filename, std::ios::binary);
  if( !is.good() ) return false;
  size_t length = System::FileSize(filename);
  char * str = new char[length];
  is.read( str, length );
  bool b = ParseDump( str, length );
  delete[] str;
  return b;
}

bool ASN1::ParseDump(const char *array, size_t length)
{
#ifdef GDCM_USE_SYSTEM_OPENSSL
  // check array pointer:
  // if length == 0, then return ok. This is an empty element.
  if( !array ) return !length;

  int indent = 1; // 0 is not visually nice
  int dump = 0; // -1 => will print hex stuff
  BIO *out=NULL;

  out=BIO_new(BIO_s_file());
  assert( out );
  BIO_set_fp(out,stdout,BIO_NOCLOSE|BIO_FP_TEXT);
  if (!ASN1_parse_dump(out,(const unsigned char*)array,length,indent,dump) )
    {
    return false;
    }

  return true;
#else
  (void)array;
  (void)length;
  gdcmDebugMacro( "GDCM_USE_SYSTEM_OPENSSL is OFF" );
  return false;
#endif
}

#ifdef GDCM_USE_SYSTEM_OPENSSL
static int print_hex(unsigned char *buf, int len)
{
  int i;
  int n;

  for(i=0,n=0;i<len;i++){
    if(n > 7){
      printf("\n");
      n = 0;
    }
    printf("0x%02x, ",buf[i]);
    n++;
  }
  printf("\n");

  return(0);
}
#endif


int ASN1::TestPBKDF2()
{
#ifdef GDCM_USE_SYSTEM_OPENSSL
  const char pass[] = "password";
  const char salt[] = "12340000";
  int ic = 1;
  unsigned char buf[1024];

  ic = 1;
  PKCS5_PBKDF2_HMAC_SHA1(pass, (int)strlen(pass), (const unsigned char*)salt,
    (int)strlen(salt), ic, 32+16, buf);
  printf("PKCS5_PBKDF2_HMAC_SHA1(\"%s\", \"%s\", %d)=\n", pass, salt, ic);
  print_hex(buf, 32+16);

  ic = 1;
  EVP_BytesToKey(EVP_aes_256_cbc(), EVP_sha1(), (const unsigned char*)salt,
    (const unsigned char*)pass, (int)strlen(pass), ic, buf, buf+32);
  printf("EVP_BytesToKey(\"%s\", \"%s\", %d)=\n", pass, salt, ic);
  print_hex(buf, 32+16);

#endif
  return 0;
}

} // end namespace gdcm
