/*===========================================================================
 Name                         : kbkdf.h
 Author of initial draft      : Volodymyr Leschenko
 Supporting                   : Samsung FIPS team
 Version                      : 1.0
 Copyright                    : Samsung Electronics
 Description :
    The kbkdf.c header file.
   "NIST Special Publication 800-108
    Recommendation for Key Derivation
    Using Pseudorandom Functions"

    NIST SP 800-108 Key Derivation Function (KDF). Counter mode.
  ===========================================================================*/
#ifndef SCRYPTO_HEADER_KBKDF_H_
#define SCRYPTO_HEADER_KBKDF_H_

#include <stdint.h>
#include <openssl/base.h>

/*===========================================================================
 *  Definitions of constants.
  ===========================================================================*/


//  Default mode of KDF execution, all records in Fixed Input Data Block
//  used as specified in NIST Special Publication 800-108, (sp800-108.pdf,
//  i.5.1, 'process, i.4').
#define KDF_DEFAULT                             0
//  Test mode of KDF execution for test vectors from NIST KDFCTR_gen.txt,
//  Iteration Counter (i) with RLEN (8, 16, 32 bits), that passed in 'rlen',
//  saved before or after Fixed Data Block, that passed in 'Context' argument.
//  If 'KDF_TEST_CTRLOCATION_MIDDLE_FIXED' selected,
//  the 'DataBeforeCtrData' and 'DataBeforeCtrLen'
//  must be passed in 'Label' and 'LabelLength', and
//  the 'DataAfterCtrData' and 'DataAfterCtrLen'
//  must be passed in 'Context' and 'ContextLength'.
//  For any other test modes used only 'Label' and 'LabelLength' respectively.
#define KDF_TEST_CTRLOCATION_BEFORE_FIXED       1
#define KDF_TEST_CTRLOCATION_MIDDLE_FIXED       2
#define KDF_TEST_CTRLOCATION_AFTER_FIXED        3

//  The Iteration Counter (i) length (RLEN) in bytes for default and test modes.
#define KDF_RLEN_08BIT                          1
#define KDF_RLEN_16BIT                          2
#define KDF_RLEN_24BIT                          3
#define KDF_RLEN_32BIT                          4

/*
 * Min and Max output data length for KDF in bits and bytes (implementation dependent).
 * NIST Special Publication 800-108 restrict max output only by max possible counter value.
 */
#define MIN_KDF_OUTPUT_LENGTH_BITS  512
#define MAX_KDF_OUTPUT_LENGTH_BITS  4096 // For SHA512.

#define MIN_KDF_OUTPUT_LENGTH_BYTES (MIN_KDF_OUTPUT_LENGTH_BITS /  8)
#define MAX_KDF_OUTPUT_LENGTH_BYTES (MAX_KDF_OUTPUT_LENGTH_BITS /  8)


#ifdef  __cplusplus
extern "C" {
#endif

/*
 * @brief The KDF in Counter Mode, used HMAC with SHA512.
 * Supports Keying material output with length divisible by 64 bytes.
 *
 * @param [in]  mode          The mode of execution, see kbkdf.h header file.
 * @param [in]  rlen          The length for Iteration Counter (i) in bytes,
 *                            see kbkdf.h header file.
 * @param [in]  *Ki           Key derivation key, a key that is used as an
 *                            input to a key derivation function.
 * @param [in]  KiLength      The length of key derivation key in bytes.
 * @param [out] *Ko           Keying material output from a key derivation function.
 * @param [out] *L            The length of requested output keying material
 *                            in bytes, returned actual output keying material
 *                            length in bytes that may be higher or equal the
 *                            requested length. Max and min values of length specified:
 *                            MIN_KDF_OUTPUT_LENGTH_BYTES and MAX_KDF_OUTPUT_LENGTH_BYTES.
 * @param [in]  *Label        A string that identifies the purpose for the
 *                            derived keying material, which is encoded as
 *                            a binary string.
 * @param [in] LabelLength    The length of 'Label' in bytes.
 * @param [in] *Context       A binary string containing the information
 *                            related to the derived keying material.
 * @param [in] ContextLength  The length of 'Context' in bytes.
 *
 * @return                    1 on success, 0 on error
 *
 */
OPENSSL_EXPORT int NIST_KDF_HMAC_SHA512_Ctr_Mode(uint8_t mode, size_t rlen,
    const uint8_t *Ki, size_t KiLength, uint8_t *Ko, uint32_t *L,
    const uint8_t *Label, size_t LabelLength,
    const uint8_t *Context, size_t ContextLength);

#ifdef  __cplusplus
}
#endif

#endif  /* SCRYPTO_HEADER_KBKDF_H_ */