/* Microsoft Reference Implementation for TPM 2.0
 *
 *  The copyright in this software is being made available under the BSD License,
 *  included below. This software may be subject to other third party and
 *  contributor rights, including patent rights, and no such rights are granted
 *  under this license.
 *
 *  Copyright (c) Microsoft Corporation
 *
 *  All rights reserved.
 *
 *  BSD License
 *
 *  Redistribution and use in source and binary forms, with or without modification,
 *  are permitted provided that the following conditions are met:
 *
 *  Redistributions of source code must retain the above copyright notice, this list
 *  of conditions and the following disclaimer.
 *
 *  Redistributions in binary form must reproduce the above copyright notice, this
 *  list of conditions and the following disclaimer in the documentation and/or
 *  other materials provided with the distribution.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ""AS IS""
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
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 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
//** Introduction
// This file contains the structure definitions used for ECC in the OpenSSL
// version of the code. These definitions would change, based on the library.
// The ECC-related structures that cross the TPM interface are defined
// in TpmTypes.h
//

#ifndef MATH_LIB_DEFINED
#define MATH_LIB_DEFINED

#define MATH_LIB_OSSL

#include <openssl/evp.h>
#include <openssl/ec.h>

#define SYMMETRIC_ALIGNMENT RADIX_BYTES

#if OPENSSL_VERSION_NUMBER >= 0x10200000L
// Check the bignum_st definition in crypto/bn/bn_lcl.h and either update the
// version check or provide the new definition for this version.
#  error Untested OpenSSL version
#elif OPENSSL_VERSION_NUMBER >= 0x10100000L
// from crypto/bn/bn_lcl.h
struct bignum_st
{
    BN_ULONG* d;   /* Pointer to an array of 'BN_BITS2' bit
                                    * chunks. */
    int       top; /* Index of last used d +1. */
                   /* The next are internal book keeping for bn_expand. */
    int dmax;      /* Size of the d array. */
    int neg;       /* one if the number is negative */
    int flags;
};
#else
#  define EC_POINT_get_affine_coordinates EC_POINT_get_affine_coordinates_GFp
#  define EC_POINT_set_affine_coordinates EC_POINT_set_affine_coordinates_GFp
#endif  // OPENSSL_VERSION_NUMBER

#include <openssl/bn.h>

//** Macros and Defines

// Make sure that the library is using the correct size for a crypt word
#if defined THIRTY_TWO_BIT && (RADIX_BITS != 32)                \
    || ((defined SIXTY_FOUR_BIT_LONG || defined SIXTY_FOUR_BIT) \
        && (RADIX_BITS != 64))
#  error Ossl library is using different radix
#endif

// Allocate a local BIGNUM value. For the allocation, a bigNum structure is created
// as is a local BIGNUM. The bigNum is initialized and then the BIGNUM is
// set to reference the local value.
#define BIG_VAR(name, bits)      \
  BN_VAR(name##Bn, (bits));      \
  BIGNUM  _##name;               \
  BIGNUM* name = BigInitialized( \
      &_##name, BnInit(name##Bn, BYTES_TO_CRYPT_WORDS(sizeof(_##name##Bn.d))))

// Allocate a BIGNUM and initialize with the values in a bigNum initializer
#define BIG_INITIALIZED(name, initializer) \
  BIGNUM  _##name;                         \
  BIGNUM* name = BigInitialized(&_##name, initializer)

typedef struct
{
    const ECC_CURVE_DATA* C;    // the TPM curve values
    EC_GROUP*             G;    // group parameters
    BN_CTX*               CTX;  // the context for the math (this might not be
                                // the context in which the curve was created>;
} OSSL_CURVE_DATA;

typedef OSSL_CURVE_DATA* bigCurve;

#define AccessCurveData(E) ((E)->C)

#include "TpmToOsslSupport_fp.h"

// Start and end a context within which the OpenSSL memory management works
#define OSSL_ENTER() BN_CTX* CTX = OsslContextEnter()
#define OSSL_LEAVE() OsslContextLeave(CTX)

// Start and end a context that spans multiple ECC functions. This is used so that
// the group for the curve can persist across multiple frames.
#define CURVE_INITIALIZED(name, initializer) \
  OSSL_CURVE_DATA _##name;                   \
  bigCurve        name = BnCurveInitialize(&_##name, initializer)
#define CURVE_FREE(name) BnCurveFree(name)

// Start and end a local stack frame within the context of the curve frame
#define ECC_ENTER() BN_CTX* CTX = OsslPushContext(E->CTX)
#define ECC_LEAVE() OsslPopContext(CTX)

#define BN_NEW() BnNewVariable(CTX)

// This definition would change if there were something to report
#define MathLibSimulationEnd()

#endif  // MATH_LIB_DEFINED
