/* Copyright 2005-2006, Voltage Security, all rights reserved.
 */
#include "vibecrypto.h"
#include "environment.h"
#include "base.h"
#include "libctx.h"
#include "paramobj.h"
#include "dh.h"
#include "mpint.h"
#include "random.h"
#include "errorctx.h"

int VtParamGenImplDHParams (
   VtParameterObject object,
   Pointer info,
   unsigned int flag,
   VtRandomObject random
   )
{
  int status;
  unsigned int primeSizeBits, bufferSize;
  VoltParameterObject *obj = (VoltParameterObject *)object;
  VoltLibCtx *libCtx = (VoltLibCtx *)(obj->voltObject.libraryCtx);
  unsigned char *buffer = (unsigned char *)0;
  VoltDHParamGenCtx *dhGenCtx;
  VOLT_DECLARE_FNCT_LINE (fnctLine)

  do
  {
    /* Check the flag, it should be VOLT_PARAM_SET_TYPE_FLAG.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_INVALID_TYPE;
    if (flag != VOLT_PARAM_SET_TYPE_FLAG)
      break;

    /* Check the paramType of the object. It should be 0.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_INVALID_SET;
    if (obj->paramType != 0)
      break;

    /* The associated info should be a pointer to an unsigend int.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_INVALID_ASSOCIATED_INFO;
    if (info == (Pointer)0)
      break;

    primeSizeBits = *((unsigned int *)info);

    /* Make sure it's a valid length.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    if (primeSizeBits != 1024)
      break;

    /* If using this ParamGenImpl, the object must already have an mpCtx
     * loaded.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_INVALID_PARAM_OBJ;
    if (obj->mpCtx == (VoltMpIntCtx *)0)
      break;

    /* Allocate enough space for a DHParamGenCtx.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_MEMORY;
    bufferSize = sizeof (VoltDHParamGenCtx);
    buffer = (unsigned char *)Z2Malloc (bufferSize, 0);
    if (buffer == (unsigned char *)0)
      break;
    Z2Memset (buffer, 0, bufferSize);

    /* Locate the context.
     */
    dhGenCtx = (VoltDHParamGenCtx *)buffer;

    dhGenCtx->primeSizeBits = primeSizeBits;
    dhGenCtx->subprimeSizeBits = 160;

    obj->paramType = VOLT_PARAM_TYPE_GENERATE | VOLT_PARAM_ALG_DH;
    obj->GenerateParameters = DHGenerateParameters;
    obj->localGenerateCtx = (Pointer)dhGenCtx;
    obj->LocalGenerateCtxDestroy = VoltSimpleCtxDestroy;

    status = 0;

  } while (0);

  /* If everything worked, return 0.
   */
  if (status == 0)
    return (0);

  /* If something went wrong, destroy anything we created and indicate
   * that this object is not usable.
   */
  if (buffer != (unsigned char *)0)
    Z2Free (buffer);

  obj->paramType = 0;

  VOLT_LOG_ERROR_INFO_COMPARE (
    status, 0, object, status, 0, VT_ERROR_TYPE_PRIMARY,
    (char *)0, "VtParamGenImplDHParams", fnctLine, (char *)0)

  return (status);
}