/* Copyright (C) 2014 by Bundesamt für Sicherheit in der Informationstechnik
 * Software engineering by Intevation GmbH
 *
 * This file is Free Software under the GNU GPL (v>=2)
 * and comes with ABSOLUTELY NO WARRANTY!
 * See LICENSE.txt for details.
 */
#include <stdlib.h>

#include "certhelp.h"
#include "logging.h"
#include "errorcodes.h"
#include "strhelp.h"

char *
get_oid_valstr(x509_name *namebuf, unsigned char *oid)
{
  char *str = NULL;
  size_t oid_len = strlen((char *)oid);
  while ( namebuf != NULL )
    {
      if ( (namebuf->oid.len == oid_len) &&
           (memcmp(namebuf->oid.p, oid, oid_len) == 0) )
        {
          str = xstrndup((char *)namebuf->val.p, namebuf->val.len);
          break;
        }
      namebuf = namebuf->next;
    }
  return str;
}

char *
x509_parse_subject(unsigned char *derdata, size_t derlen,
                   unsigned char *oid)
{
  x509_crt chain;
  char *str;

  x509_crt_init(&chain);
  if (x509_crt_parse_der(&chain, derdata, derlen) != 0)
    {
      ERRORPRINTF("Could not parse certificate!\n");
      return NULL;
    }
  else
    {
      str = get_oid_valstr(&(chain.subject), oid);
      x509_crt_free(&chain);
    }
  return str;
}

#ifdef WIN32
PCCERT_CONTEXT
b64_to_cert_context(char *b64_data, size_t b64_size)
{
  size_t buf_size = 0;
  char *buf = NULL;
  PCCERT_CONTEXT pCert = NULL;
  int ret = -1;

  ret = str_base64_decode (&buf, &buf_size, b64_data, b64_size);

  if (ret != 0)
    {
      ERRORPRINTF ("decoding certificate failed\n");
      return NULL;
    }

  pCert = CertCreateContext (CERT_STORE_CERTIFICATE_CONTEXT,
                             X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
                             (const PBYTE) buf,
                             (DWORD) buf_size,
                             0,
                             NULL);
  free (buf); /* Windows has a copy */

  if (pCert == NULL)
    {
      char *error = getLastErrorMsg();
      if (error)
        {
          ERRORPRINTF ("Failed to create cert context: %s \n", error);
          free (error);
        }
      return NULL;
    }
  return pCert;
}
#endif