/* Copyright 2003-2006, Voltage Security, all rights reserved.
 */

#include "vibecrypto.h"
#include "environment.h"
#include "base.h"
#include "libctx.h"
#include "paramobj.h"
#include "algobj.h"
#include "keyobj.h"
#include "mpint.h"
#include "surrender.h"

#ifndef _DH_H
#define _DH_H

#ifdef __cplusplus
extern "C" {
#endif

typedef struct
{
  unsigned int primeSizeBits;
  unsigned int subprimeSizeBits;
} VoltDHParamGenCtx;

/* Implements VGenerateParameters
 */
int VOLT_CALLING_CONV DHGenerateParameters VOLT_PROTO_LIST ((
   VtParameterObject paramObj,
   VtRandomObject random
));

/* This function generates prime P, subprime Q, and base G following
 * the instructions in the X9.42 document. The primes will be chosen
 * such that subprimeQ is a divisor of (primeP - 1).
 * <p>The SEED, and counter values are returned because the caller may
 * be doing some FIPS work and will need them. The caller must pass a
 * SEED buffer and it must be big enough to hold subprimeSizeBits. This
 * function will not check the arguments, it is the responsibility of
 * the caller to pass a valid SEED buffer (not NULL) that is big
 * enough, along with valid pointers seedLen and counter.
 * <p>The length of the subprime must be less than the length of the
 * prime. The base will be the same size as the prime.
 * <p>The caller can pass a surrender context if one is available (NULL
 * is allowed). The surrFlag is a VT_SURRENDER_FNCT_ flag (such as
 * VT_SURRENDER_FNCT_DH_PARAM_GEN) indicating who wants the PQG.
 *
 * @param mpCtx The mpCtx to use for multi-precision operations.
 * @param surrCtx This can be NULL, but if not, the surrender ctx to
 * call at various intervals.
 * @param surrFlag A VT_SURRENDER_FNCT_ flag indicating what operation
 * is running, to tell the surrender function who is calling it.
 * @param callNumber The current callNumber of the surrender ctx. The
 * caller should pass the current value at the address given, the
 * function will return the number it eventually reaches at that
 * address.
 * @param primeSizeBits The size, in bits, of the prime to generate.
 * @param subprimeSizeBits The size, in bits, of the subprime to generate.
 * @param random A random object, the source of any random bytes needed.
 * @param primeP Where the resulting prime will be deposited.
 * @param subprimeQ Where the resulting subprime will be deposited.
 * @param baseG Where the resulting base will be deposited.
 * @param SEED The buffer into which the FIPS SEED value will be placed.
 * @param seedLen The address where the function will deposit the
 * length, in bytes, of the value deposited into the SEED buffer.
 * @param counter The address where the function will deposit the FIPS
 * counter value.
 * @return an int, 0 if the function completed successfully or a
 * non-zero error code.
 */
int VOLT_CALLING_CONV VoltGeneratePQGX942 VOLT_PROTO_LIST ((
   VoltMpIntCtx *mpCtx,
   VoltSurrenderCtx *surrCtx,
   unsigned int surrFlag,
   unsigned int *callNumber,
   unsigned int primeSizeBits,
   unsigned int subprimeSizeBits,
   VtRandomObject random,
   VoltMpInt *primeP,
   VoltMpInt *subprimeQ,
   VoltMpInt *baseG,
   unsigned char *SEED,
   unsigned int *seedLen,
   unsigned int *counter
));

typedef struct
{
  VtMpIntCtx     mpCtx;
  unsigned int   primeSizeBits;
  VtItem         primeP;
  VtItem         subprimeQ;
  VtItem         baseG;
} VoltDHKeyGenCtx;

/* Implements VGenerateKey
 */
int VOLT_CALLING_CONV DHGenerateKeyPair VOLT_PROTO_LIST ((
   VtKeyObject priKey,
   VtKeyObject pubKey,
   VtRandomObject random
));

#define VOLT_DH_PRI_VAL_LEN  20

/* This is part of FIPS random x and k generation.
 */
#define VOLT_DH_XKEY_LEN     32
#define VOLT_DH_XSEED_LEN    32

/* This is how params are stored internally.
 */
typedef struct
{
  VoltMpInt          *primeP;
  VoltMpInt          *subprimeQ;
  VoltMpInt          *baseG;
  VtDHParamInfo       paramInfo;
  VtDHParamFipsInfo   fipsInfo;
} VoltDHParams;

/* If the DH param info is given by MpInt's, call this routine to store
 * the info in the object.
 * <p>If the FIPS info (SEED, counter) is available, pass it in. If
 * not, don't.
 * <p>This function does not check the args, it is the responsibility
 * of the caller to pass in a valid parameter object with an mpCtx
 * inside, valid MpInts (the subprimeQ can be NULL), a valid SEED (or
 * NULL with length 0), and the correct counter (or 0).
 * <p>In fact, it is the responsibility of the caller to make sure the
 * args match. That is, if the SEED is NULL, then the seedLen MUST be
 * 0 and the counter MUST be 0. If the counter is 0, then there can be
 * no SEED.
 * <p>If there is a SEED and counter, there MUST be a subprime.
 */
int VOLT_CALLING_CONV VoltAddDHParametersMpInt VOLT_PROTO_LIST ((
   VoltParameterObject *obj,
   VoltMpInt *primeP,
   VoltMpInt *subprimeQ,
   VoltMpInt *baseG,
   unsigned char *SEED,
   unsigned int seedLen,
   unsigned int counter
));

/* This is how DH key data is stored internally.
 * If you build a key and store the key data, it must be this format.
 * That is, if the VOLT_KEY_TYPE_DATA bit in the keyObject->keyType
 * field is set, the keyData must point to this struct.
 * Each of the types, public, private and key pair, must begin with the
 * keyType field, a flag so we can know what the struct is. It will be
 * set to one of the following values.
 *
 *    VOLT_KEY_TYPE_PUBLIC
 *    VOLT_KEY_TYPE_PRIVATE
 *    VOLT_KEY_TYPE_PAIR
 *
 * The public and private key types must look alike from top to bottom,
 * except for the priValX at the bottom. They can both be dereferenced
 * as a public key and the keyItems and params will be in the same
 * place.
 */
typedef struct
{
  unsigned int type;
  VtDHPriKeyInfo *keyItems;
  VoltMpInt *primeP;
  VoltMpInt *subprimeQ;
  VoltMpInt *baseG;
  VoltMpInt *pubValY;
  VoltMpInt *priValX;
} VoltDHPrivateKey;

typedef struct
{
  unsigned int type;
  VtDHPubKeyInfo *keyItems;
  VoltMpInt *primeP;
  VoltMpInt *subprimeQ;
  VoltMpInt *baseG;
  VoltMpInt *pubValY;
} VoltDHPublicKey;

typedef struct
{
  unsigned int type;
  VtKeyObject pubKey;
  VtKeyObject priKey;
} VoltDHKeyPair;

/* Implements VGenerateKey
 */
int VOLT_CALLING_CONV DHGenerateKeyPair VOLT_PROTO_LIST ((
   VtKeyObject priKey,
   VtKeyObject pubKey,
   VtRandomObject random
));

/* Implements VGenerateSharedSecret
 */
int VOLT_CALLING_CONV VoltDHGenerateSharedSecret VOLT_PROTO_LIST ((
   VoltAlgorithmObject *obj,
   VtKeyObject otherPartyPubKey,
   VtKeyObject myPriKey,
   VtKeyObject sharedSecret,
   VtRandomObject random
));
/* Perform Diffie-Hellman. This determines if a pub and pri key are
 * indeed DH partners.
 * <p>If the two are partners, this function will return 0. If the keys
 * are not, the function will return an error code.
 * <p>This routine assumes that the random object is valid.
 *
 * @param libCtx The libCtx to use.
 * @param surrCtx If not NULL, pass it on to any function that takes a
 * surrender ctx.
 * @param pubKey The alleged public key.
 * @param priKey The alleged private key.
 * @param random A random object to use as a source of any random bytes
 * if needed.
 * @return an int, 0 if the function completed successfully or a
 * non-zero error code.
 */
int VOLT_CALLING_CONV VoltTestDHKeyPair VOLT_PROTO_LIST ((
   VoltLibCtx *libCtx,
   VoltSurrenderCtx *surrCtx,
   VtKeyObject pubKey,
   VtKeyObject priKey,
   VtRandomObject random
));

/* Implements VCtxDestroy.
 */
void VOLT_CALLING_CONV DHParameterDataDestroy VOLT_PROTO_LIST ((
   Pointer obj,
   Pointer ctx
));

/* Implements VCopyParams.
 */
int VOLT_CALLING_CONV DHCopyParams VOLT_PROTO_LIST ((
   Pointer sourceParamObj,
   Pointer destParamObj
));

/* Implements VCtxDestroy.
 */
void VOLT_CALLING_CONV DHKeyDataDestroy VOLT_PROTO_LIST ((
   Pointer obj,
   Pointer ctx
));

/* Implements VCloneObject.
 */
int VOLT_CALLING_CONV VoltCloneDHPubKey VOLT_PROTO_LIST ((
   Pointer sourceObject,
   Pointer *destObject
));

/* Implements VCloneObject.
 */
int VOLT_CALLING_CONV VoltCloneDHPriKey VOLT_PROTO_LIST ((
   Pointer sourceObject,
   Pointer *destObject
));

/* Implements VCloneObject.
 */
int VOLT_CALLING_CONV VoltCloneDHSharedSecret VOLT_PROTO_LIST ((
   Pointer sourceObject,
   Pointer *destObject
));

#ifdef __cplusplus
}
#endif

#endif /* _DH_H */