/* Copyright 2003-2006, Voltage Security, all rights reserved.
 */
#include "vibecrypto.h"
#include "environment.h"
#include "base.h"
#include "libctx.h"
#include "algobj.h"
#include "sign.h"
#include "dsa.h"
#include "mpint.h"
#include "errorctx.h"

int VtAlgorithmImplDSASign (
   VtAlgorithmObject *object,
   Pointer info,
   unsigned int flag
   )
{
  int status;
#if VOLT_ALIGNMENT != 1
  unsigned int pad;
#endif
  unsigned int sigFormat, bufferSize, offset;
  VoltAlgorithmObject *obj = (VoltAlgorithmObject *)(*object);
  VoltLibCtx *libCtx = (VoltLibCtx *)(obj->voltObject.libraryCtx);
  unsigned char *buffer = (unsigned char *)0;
  VoltSignClassCtx *ctx;
  VoltDsaSignCtx *dsaCtx;
  VOLT_DECLARE_FNCT_LINE (fnctLine)

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

    /* Check the class of the object. It should be 0 (not yet set).
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_INVALID_SET;
    if (obj->algClass != 0)
      break;

    /* The associated info should be a pointer to an unsigned int, one
     * of the allowed signature formats.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_INVALID_ASSOCIATED_INFO;
    if (info == (Pointer)0)
      break;

    VOLT_SET_FNCT_LINE (fnctLine)
    sigFormat = *((unsigned int *)info);
    if ( (sigFormat != VT_DSA_SIGNATURE_R_S) &&
         (sigFormat != VT_DSA_SIGNATURE_DER_ENCODED) )
      break;

    /* Allocate space for the VoltSignClassCtx and the local context.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_MEMORY;
    bufferSize = sizeof (VoltSignClassCtx) + sizeof (VoltDsaSignCtx);
#if VOLT_ALIGNMENT != 1
    /* If the alignment is 1, there's no need to pad. If not, compute
     * the pad length.
     */
    VOLT_COMPUTE_ALIGN_PAD (VOLT_ALIGNMENT, sizeof (VoltSignClassCtx), pad)
    bufferSize += pad;
#endif
    buffer = (unsigned char *)Z2Malloc (bufferSize, 0);
    if (buffer == (unsigned char *)0)
      break;
    Z2Memset (buffer, 0, bufferSize);

    ctx = (VoltSignClassCtx *)buffer;
    offset = sizeof (VoltSignClassCtx);
#if VOLT_ALIGNMENT != 1
    offset += pad;
#endif
    dsaCtx = (VoltDsaSignCtx *)(buffer + offset);
    dsaCtx->format = sigFormat;

    ctx->GetDigestObject = DSAGetDigestObject;
    ctx->CheckSignatureInput = DSACheckSignatureInput;
    ctx->SignData = DSASignData;
    ctx->algorithm |= VOLT_SIGNATURE_ALG_DSA;
    ctx->localSignCtx = (Pointer)dsaCtx;
    ctx->LocalSignCtxDestroy = DSASignCtxDestroy;

    obj->algClass = VOLT_CLASS_SIGNATURE;
    obj->classCtx = (Pointer)ctx;
    obj->ClassCtxDestroy = VoltSignCtxDestroy;

    status = 0;

  } while (0);

  /* If success, we're done.
   */
  if (status == 0)
  {
    /* Set the FIPS bit in the object type, this object is a FIPS
     * object.
     */
    obj->voltObject.objectType |= VOLT_OBJECT_TYPE_FIPS;
    return (0);
  }

  /* If there was an error, free up any memory this function allocated.
   */
  if (buffer != (unsigned char *)0)
    Z2Free (buffer);

  VOLT_LOG_ERROR (
    (VtLibCtx)libCtx, status, VT_ERROR_TYPE_PRIMARY, fnctLine,
    "VtAlgorithmImplDSASign", (char *)0)

  return (status);
}

int VtAlgorithmImplDSAVerify (
   VtAlgorithmObject *object,
   Pointer info,
   unsigned int flag
   )
{
  int status;
#if VOLT_ALIGNMENT != 1
  unsigned int pad;
#endif
  unsigned int sigFormat, bufferSize, offset;
  VoltAlgorithmObject *obj = (VoltAlgorithmObject *)(*object);
  VoltLibCtx *libCtx = (VoltLibCtx *)(obj->voltObject.libraryCtx);
  unsigned char *buffer = (unsigned char *)0;
  VoltSignClassCtx *ctx;
  VoltDsaSignCtx *dsaCtx;
  VOLT_DECLARE_FNCT_LINE (fnctLine)

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

    /* Check the class of the object. It should be 0 (not yet set).
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_INVALID_SET;
    if (obj->algClass != 0)
      break;

    /* The associated info should be a pointer to an unsigned int, one
     * of the allowed signature formats.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_INVALID_ASSOCIATED_INFO;
    if (info == (Pointer)0)
      break;

    VOLT_SET_FNCT_LINE (fnctLine)
    sigFormat = *((unsigned int *)info);
    if ( (sigFormat != VT_DSA_SIGNATURE_R_S) &&
         (sigFormat != VT_DSA_SIGNATURE_DER_ENCODED) )
      break;

    /* Allocate space for the VoltSignClassCtx and the local context.
     * The local context is simply the sig format, which can be
     * represented in an unsigned int.
     */
    VOLT_SET_FNCT_LINE (fnctLine)
    status = VT_ERROR_MEMORY;
    bufferSize = sizeof (VoltSignClassCtx) + sizeof (VoltDsaSignCtx);
#if VOLT_ALIGNMENT != 1
    /* If the alignment is 1, there's no need to pad. If not, compute
     * the pad length.
     */
    VOLT_COMPUTE_ALIGN_PAD (VOLT_ALIGNMENT, sizeof (VoltSignClassCtx), pad)
    bufferSize += pad;
#endif
    buffer = (unsigned char *)Z2Malloc (bufferSize, 0);
    if (buffer == (unsigned char *)0)
      break;
    Z2Memset (buffer, 0, bufferSize);

    ctx = (VoltSignClassCtx *)buffer;
    offset = sizeof (VoltSignClassCtx);
#if VOLT_ALIGNMENT != 1
    offset += pad;
#endif
    dsaCtx = (VoltDsaSignCtx *)(buffer + offset);
    dsaCtx->format = sigFormat;

    ctx->GetDigestObject = DSAGetDigestObject;
    ctx->VerifyData = DSAVerifyData;
    ctx->algorithm |= VOLT_SIGNATURE_ALG_DSA;
    ctx->localSignCtx = (Pointer)dsaCtx;
    ctx->LocalSignCtxDestroy = DSASignCtxDestroy;

    obj->algClass = VOLT_CLASS_VERIFY;
    obj->classCtx = (Pointer)ctx;
    obj->ClassCtxDestroy = VoltSignCtxDestroy;

    status = 0;

  } while (0);

  /* If success, we're done.
   */
  if (status == 0)
  {
    /* Set the FIPS bit in the object type, this object is a FIPS
     * object.
     */
    obj->voltObject.objectType |= VOLT_OBJECT_TYPE_FIPS;
    return (0);
  }

  /* If there was an error, free up any memory this function allocated.
   */
  if (buffer != (unsigned char *)0)
    Z2Free (buffer);

  VOLT_LOG_ERROR (
    (VtLibCtx)libCtx, status, VT_ERROR_TYPE_PRIMARY, fnctLine,
    "VtAlgorithmImplDSAVerify", (char *)0)

  return (status);
}

int VtAlgorithmImplDSASignVerify (
   VtAlgorithmObject *object,
   Pointer info,
   unsigned int flag
   )
{
  int status;
  VoltAlgorithmObject *obj = (VoltAlgorithmObject *)(*object);
  VoltSignClassCtx *ctx;
  VOLT_DECLARE_FNCT_LINE (fnctLine)

  /* Set this up to sign, then add verify capabilities.
   */
  VOLT_SET_FNCT_LINE (fnctLine)
  status = VtAlgorithmImplDSASign (object, info, flag);
  if (status == 0)
  {
    ctx = (VoltSignClassCtx *)(obj->classCtx);
    ctx->VerifyData = DSAVerifyData;
    obj->algClass |= VOLT_CLASS_VERIFY;
  }

  VOLT_LOG_ERROR_INFO_COMPARE (
    status, 0, *object, status, 0, 0,
    (char *)0, "VtAlgorithmImplDSASignVerify", fnctLine, (char *)0)

  return (status);
}

int DSAGetDigestObject (
   VoltAlgorithmObject *obj,
   VtAlgorithmObject *digestObject
   )
{
  int status;
  VoltSignClassCtx *ctx = (VoltSignClassCtx *)(obj->classCtx);
  VtAlgorithmObject newObject = (VtAlgorithmObject)0;
  VOLT_DECLARE_FNCT_LINE (fnctLine)

  do
  {
    /* If we don't have an object built, build it.
     */
    if (ctx->digestObject == (VtAlgorithmObject)0)
    {
      VOLT_SET_FNCT_LINE (fnctLine)
      status = VtCreateAlgorithmObject (
        obj->voltObject.libraryCtx, VtAlgorithmImplSHA1, (Pointer)0,
        &newObject);
      if (status != 0)
        break;

      ctx->digestObject = newObject;
    }

    *digestObject = ctx->digestObject;
    status = 0;

  } while (0);

  if (status == 0)
    return (0);

  VtDestroyAlgorithmObject (&newObject);

  VOLT_LOG_ERROR (
    obj->voltObject.libraryCtx, status, 0, fnctLine,
    "DSAGetDigestObject", (char *)0)

  return (status);
}

void DSASignCtxDestroy (
   Pointer obj,
   Pointer ctx
   )
{
  VoltObject *voltObj;
  VoltLibCtx *libCtx;
  VoltDsaSignCtx *dsaCtx;

  /* Anything to destroy?
   */
  if ( (obj == (Pointer)0) || (ctx == (Pointer)0) )
    return;

  voltObj = (VoltObject *)obj;
  dsaCtx = (VoltDsaSignCtx *)ctx;
  libCtx = (VoltLibCtx *)(voltObj->libraryCtx);

  VtDestroyKeyObject (&(dsaCtx->tempKey));

  /* Don't free the memory, it's part of the full signCtx.
   */
}

void VoltSignCtxDestroy (
   Pointer obj,
   Pointer ctx
   )
{
  VoltObject *voltObj;
  VoltLibCtx *libCtx;
  VoltSignClassCtx *signCtx;

  /* Anything to destroy?
   */
  if ( (obj == (Pointer)0) || (ctx == (Pointer)0) )
    return;

  voltObj = (VoltObject *)obj;
  signCtx = (VoltSignClassCtx *)ctx;
  libCtx = (VoltLibCtx *)(voltObj->libraryCtx);

  VtDestroyAlgorithmObject (&(signCtx->digestObject));

  if (signCtx->LocalSignCtxDestroy != (VCtxDestroy)0)
    signCtx->LocalSignCtxDestroy (obj, signCtx->localSignCtx);
  if (signCtx->PadCtxDestroy != (VCtxDestroy)0)
    signCtx->PadCtxDestroy (obj, signCtx->padCtx);

  Z2Free (ctx);
}