/*
 * (c) Copyright, Real-Time Innovations, 2025.
 * All rights reserved.
 *
 * No duplications, whole or partial, manual or electronic, may be made
 * without express written permission.  Any such copies, or
 * revisions thereof, must display this notice unaltered.
 * This code contains trade secrets of Real-Time Innovations, Inc.
 */

#ifndef osapi_sha1_h
#define osapi_sha1_h

#include "osapi/osapi_dll.h"
#include "osapi/osapi_type.h"

#define RTI_OSAPI_SHA1_DIGEST_SIZE 20

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @internal
 * @brief SHA1 state structure for incremental hashing.
 */
struct RTIOsapiSHA1State {
    RTI_UINT32 State[5];
    RTI_UINT32 Count[2];
    RTI_UINT8 Buffer[64];
};

/**
 * @internal
 * @brief Initializes or resets a SHA1 state.
 *
 * @attention This SHA1 implementation is not intended for use in any
 * security-related features and MUST NOT BE USED for such purposes.
 *
 * @param[out] self Pointer to the SHA1 state to initialize.
 */
extern RTIOsapiDllExport void RTIOsapiSHA1State_start(
        struct RTIOsapiSHA1State *self);

/**
 * @internal
 * @brief Adds data to the SHA1 state.
 *
 * This processes the data and updates the internal state.
 * Call repeatedly until all data is added, then call RTIOsapiSHA1State_finish.
 *
 * @attention This SHA1 implementation is not intended for use in any
 * security-related features and MUST NOT BE USED for such purposes.
 *
 * @param[in,out] self Pointer to the SHA1 state.
 * @param[in] input Pointer to the data buffer to add.
 * @param[in] inputSize Size of the data buffer in bytes.
 */
extern RTIOsapiDllExport void RTIOsapiSHA1State_update(
        struct RTIOsapiSHA1State *self,
        const RTI_UINT8 *input,
        RTI_UINT32 inputSize);

/**
 * @internal
 * @brief Finalizes the SHA1 hash and writes the digest.
 *
 * After calling this, RTIOsapiSHA1State_start must be used to reuse the state.
 *
 * @attention This SHA1 implementation is not intended for use in any
 * security-related features and MUST NOT BE USED for such purposes.
 *
 * @param[in,out] self Pointer to the SHA1 state.
 * @param[out] digest Pointer to a buffer to receive the hash.
 */
extern RTIOsapiDllExport void RTIOsapiSHA1State_finish(
        struct RTIOsapiSHA1State *self,
        RTI_UINT8 *digest);

/**
 * @internal
 * @brief Calculates the SHA1 hash of a buffer in one call.
 *
 * Combines start, update, and finish into a single operation.
 *
 * @attention This SHA1 implementation is not intended for use in any
 * security-related features and MUST NOT BE USED for such purposes.
 *
 * @param[out] digest Pointer to a buffer to receive the hash.
 * @param[in] input Pointer to the data buffer to hash.
 * @param[in] inputSize Size of the data buffer in bytes.
 */
extern RTIOsapiDllExport void RTIOsapiSHA1_computeSHA1(
        RTI_UINT8 *digest,
        const char *input,
        size_t inputSize);

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* osapi_sha1_h */