/*
 * SHA-512 implementation with hardware ESP support added.
 *
 * SPDX-FileCopyrightText: The Mbed TLS Contributors
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * SPDX-FileContributor: 2016-2023 Espressif Systems (Shanghai) CO LTD
 */
/*
 *  The SHA-512 Secure Hash Standard was published by NIST in 2002.
 *
 *  http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
 */

#include <mbedtls/build_info.h>

#if defined(MBEDTLS_SHA512_C) && defined(MBEDTLS_SHA512_ALT)

#include "mbedtls/sha512.h"

#if defined(_MSC_VER) || defined(__WATCOMC__)
#define UL64(x) x##ui64
#else
#define UL64(x) x##ULL
#endif

#include <string.h>
#include <assert.h>

#if defined(MBEDTLS_SELF_TEST)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdio.h>
#define mbedtls_printf printf
#endif /* MBEDTLS_PLATFORM_C */
#endif /* MBEDTLS_SELF_TEST */

#include "sha/sha_block.h"

/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n )
{
    volatile unsigned char *p = v;
    while ( n-- ) {
        *p++ = 0;
    }
}

/*
 * 64-bit integer manipulation macros (big endian)
 */
#ifndef PUT_UINT64_BE
#define PUT_UINT64_BE(n,b,i)                            \
{                                                       \
    (b)[(i)    ] = (unsigned char) ( (n) >> 56 );       \
    (b)[(i) + 1] = (unsigned char) ( (n) >> 48 );       \
    (b)[(i) + 2] = (unsigned char) ( (n) >> 40 );       \
    (b)[(i) + 3] = (unsigned char) ( (n) >> 32 );       \
    (b)[(i) + 4] = (unsigned char) ( (n) >> 24 );       \
    (b)[(i) + 5] = (unsigned char) ( (n) >> 16 );       \
    (b)[(i) + 6] = (unsigned char) ( (n) >>  8 );       \
    (b)[(i) + 7] = (unsigned char) ( (n)       );       \
}
#endif /* PUT_UINT64_BE */

void esp_sha512_set_mode(mbedtls_sha512_context *ctx, esp_sha_type type)
{
    switch (type) {
    case SHA2_384:
    case SHA2_512224:
    case SHA2_512256:
    case SHA2_512T:
        ctx->mode = type;
        break;
    default:
        ctx->mode = SHA2_512;
        break;
    }
}


/* For SHA512/t mode the intial hash value will depend on t */
void esp_sha512_set_t( mbedtls_sha512_context *ctx, uint16_t t_val)
{
    ctx->t_val = t_val;
}

void mbedtls_sha512_init( mbedtls_sha512_context *ctx )
{
    assert(ctx != NULL);

    memset( ctx, 0, sizeof( mbedtls_sha512_context ) );
}

void mbedtls_sha512_free( mbedtls_sha512_context *ctx )
{
    if ( ctx == NULL ) {
        return;
    }

    mbedtls_zeroize( ctx, sizeof( mbedtls_sha512_context ) );
}

void mbedtls_sha512_clone( mbedtls_sha512_context *dst,
                           const mbedtls_sha512_context *src )
{
    memcpy(dst, src, sizeof(mbedtls_sha512_context));
}

/*
 * SHA-512 context setup
 */
int mbedtls_sha512_starts( mbedtls_sha512_context *ctx, int is384 )
{
    mbedtls_zeroize( ctx, sizeof( mbedtls_sha512_context ) );

    if ( is384 ) {
        ctx->mode = SHA2_384;
    } else {
        ctx->mode = SHA2_512;
    }

    return 0;
}

static int esp_internal_sha_update_state(mbedtls_sha512_context *ctx)
{
    if (ctx->sha_state == ESP_SHA512_STATE_INIT) {
        if (ctx->mode == SHA2_512T) {
            int ret = -1;
            if ((ret = esp_sha_512_t_init_hash(ctx->t_val)) != 0) {
                return ret;
            }
            ctx->first_block = false;
        } else {
            ctx->first_block = true;
        }
        ctx->sha_state = ESP_SHA512_STATE_IN_PROCESS;

    } else if (ctx->sha_state == ESP_SHA512_STATE_IN_PROCESS) {
        ctx->first_block = false;
        esp_sha_write_digest_state(ctx->mode, ctx->state);
    }
    return 0;
}

static void esp_internal_sha512_block_process(mbedtls_sha512_context *ctx, const uint8_t *data)
{
    esp_sha_block(ctx->mode, data, ctx->first_block);

    if (ctx->first_block) {
        ctx->first_block = false;
    }
}

int mbedtls_internal_sha512_process( mbedtls_sha512_context *ctx, const unsigned char data[128] )
{
    int ret = -1;
    esp_sha_acquire_hardware();

    ret = esp_internal_sha_update_state(ctx);
    if (ret != 0) {
        esp_sha_release_hardware();
        return ret;
    }

    esp_sha_block(ctx->mode, data, ctx->first_block);
    esp_sha_read_digest_state(ctx->mode, ctx->state);
    esp_sha_release_hardware();
    return ret;
}

/*
 * SHA-512 process buffer
 */
int mbedtls_sha512_update( mbedtls_sha512_context *ctx, const unsigned char *input,
                               size_t ilen )
{
    int ret;
    size_t fill;
    unsigned int left, len, local_len = 0;

    if ( ilen == 0 ) {
        return 0;
    }

    left = (unsigned int) (ctx->total[0] & 0x7F);
    fill = 128 - left;

    ctx->total[0] += (uint64_t) ilen;

    if ( ctx->total[0] < (uint64_t) ilen ) {
        ctx->total[1]++;
    }

    if ( left && ilen >= fill ) {
        memcpy( (void *) (ctx->buffer + left), input, fill );

        input += fill;
        ilen  -= fill;
        left = 0;
        local_len = 128;
    }


    if ( len || local_len) {

        esp_sha_acquire_hardware();

        int ret = esp_internal_sha_update_state(ctx);

        if (ret != 0) {
            esp_sha_release_hardware();
            return ret;
        }

        /* First process buffered block, if any */
        if ( local_len ) {
            esp_internal_sha256_block_process(ctx, ctx->buffer);
        }

        while ( ilen >= 128 ) {
            esp_internal_sha256_block_process(ctx, input);

            input += 64;
            ilen  -= 64;
        }
        esp_sha_read_digest_state(ctx->mode, ctx->state);

        esp_sha_release_hardware();
    }

    if ( ilen > 0 ) {
        memcpy( (void *) (ctx->buffer + left), input, ilen);
    }

    return 0;
}

static const unsigned char sha512_padding[128] = {
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/*
 * SHA-512 final digest
 */
int mbedtls_sha512_finish( mbedtls_sha512_context *ctx, unsigned char *output )
{
    int ret = -1;
    size_t last, padn;
    uint64_t high, low;
    unsigned char msglen[16];

    high = ( ctx->total[0] >> 61 )
           | ( ctx->total[1] <<  3 );
    low  = ( ctx->total[0] <<  3 );

    PUT_UINT64_BE( high, msglen, 0 );
    PUT_UINT64_BE( low,  msglen, 8 );

    last = (size_t)( ctx->total[0] & 0x7F );
    padn = ( last < 112 ) ? ( 112 - last ) : ( 240 - last );

    if ( ( ret = mbedtls_sha512_update( ctx, sha512_padding, padn ) ) != 0 ) {
        return ret;
    }

    if ( ( ret = mbedtls_sha512_update( ctx, msglen, 16 ) ) != 0 ) {
        return ret;
    }

    if (ctx->mode == SHA2_384) {
        memcpy(output, ctx->state, 48);
    } else {
        memcpy(output, ctx->state, 64);
    }

    return ret;
}

#endif /* MBEDTLS_SHA512_C && MBEDTLS_SHA512_ALT */