/*
 *  SHA-512 implementation with hardware ESP32 support added.
 *  Uses mbedTLS software implementation for failover when concurrent
 *  SHA operations are in use.
 *
 * SPDX-FileCopyrightText: The Mbed TLS Contributors
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * SPDX-FileContributor: 2016-2022 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>

#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_parallel_engine.h"

inline static esp_sha_type sha_type(const mbedtls_sha512_context *ctx)
{
    return ctx->is384 ? SHA2_384 : SHA2_512;
}

/* 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 GET_UINT64_BE
#define GET_UINT64_BE(n,b,i)                            \
{                                                       \
    (n) = ( (uint64_t) (b)[(i)    ] << 56 )       \
        | ( (uint64_t) (b)[(i) + 1] << 48 )       \
        | ( (uint64_t) (b)[(i) + 2] << 40 )       \
        | ( (uint64_t) (b)[(i) + 3] << 32 )       \
        | ( (uint64_t) (b)[(i) + 4] << 24 )       \
        | ( (uint64_t) (b)[(i) + 5] << 16 )       \
        | ( (uint64_t) (b)[(i) + 6] <<  8 )       \
        | ( (uint64_t) (b)[(i) + 7]       );      \
}
#endif /* GET_UINT64_BE */

#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 mbedtls_sha512_init( mbedtls_sha512_context *ctx )
{
    memset( ctx, 0, sizeof( mbedtls_sha512_context ) );
}

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

    if (ctx->mode == ESP_MBEDTLS_SHA512_HARDWARE) {
        esp_sha_unlock_engine(sha_type(ctx));
    }
    mbedtls_zeroize( ctx, sizeof( mbedtls_sha512_context ) );
}

void mbedtls_sha512_clone( mbedtls_sha512_context *dst,
                           const mbedtls_sha512_context *src )
{
    *dst = *src;

    if (src->mode == ESP_MBEDTLS_SHA512_HARDWARE) {
        /* Copy hardware digest state out to cloned state,
           which will be a software digest.

           Always read 512 bits of state, even for SHA-384
           (SHA-384 state is identical to SHA-512, only
           digest is truncated.)
        */
        esp_sha_read_digest_state(SHA2_512, dst->state);
        dst->mode = ESP_MBEDTLS_SHA512_SOFTWARE;
    }
}


/*
 * SHA-512 context setup
 */
int mbedtls_sha512_starts( mbedtls_sha512_context *ctx, int is384 )
{
    ctx->total[0] = 0;
    ctx->total[1] = 0;

    if ( is384 == 0 ) {
        /* SHA-512 */
        ctx->state[0] = UL64(0x6A09E667F3BCC908);
        ctx->state[1] = UL64(0xBB67AE8584CAA73B);
        ctx->state[2] = UL64(0x3C6EF372FE94F82B);
        ctx->state[3] = UL64(0xA54FF53A5F1D36F1);
        ctx->state[4] = UL64(0x510E527FADE682D1);
        ctx->state[5] = UL64(0x9B05688C2B3E6C1F);
        ctx->state[6] = UL64(0x1F83D9ABFB41BD6B);
        ctx->state[7] = UL64(0x5BE0CD19137E2179);
    } else {
        /* SHA-384 */
        ctx->state[0] = UL64(0xCBBB9D5DC1059ED8);
        ctx->state[1] = UL64(0x629A292A367CD507);
        ctx->state[2] = UL64(0x9159015A3070DD17);
        ctx->state[3] = UL64(0x152FECD8F70E5939);
        ctx->state[4] = UL64(0x67332667FFC00B31);
        ctx->state[5] = UL64(0x8EB44A8768581511);
        ctx->state[6] = UL64(0xDB0C2E0D64F98FA7);
        ctx->state[7] = UL64(0x47B5481DBEFA4FA4);
    }

    ctx->is384 = is384;
    if (ctx->mode == ESP_MBEDTLS_SHA512_HARDWARE) {
        esp_sha_unlock_engine(sha_type(ctx));
    }
    ctx->mode = ESP_MBEDTLS_SHA512_UNUSED;

    return 0;
}

/*
 * Round constants
 */
static const uint64_t K[80] = {
    UL64(0x428A2F98D728AE22),  UL64(0x7137449123EF65CD),
    UL64(0xB5C0FBCFEC4D3B2F),  UL64(0xE9B5DBA58189DBBC),
    UL64(0x3956C25BF348B538),  UL64(0x59F111F1B605D019),
    UL64(0x923F82A4AF194F9B),  UL64(0xAB1C5ED5DA6D8118),
    UL64(0xD807AA98A3030242),  UL64(0x12835B0145706FBE),
    UL64(0x243185BE4EE4B28C),  UL64(0x550C7DC3D5FFB4E2),
    UL64(0x72BE5D74F27B896F),  UL64(0x80DEB1FE3B1696B1),
    UL64(0x9BDC06A725C71235),  UL64(0xC19BF174CF692694),
    UL64(0xE49B69C19EF14AD2),  UL64(0xEFBE4786384F25E3),
    UL64(0x0FC19DC68B8CD5B5),  UL64(0x240CA1CC77AC9C65),
    UL64(0x2DE92C6F592B0275),  UL64(0x4A7484AA6EA6E483),
    UL64(0x5CB0A9DCBD41FBD4),  UL64(0x76F988DA831153B5),
    UL64(0x983E5152EE66DFAB),  UL64(0xA831C66D2DB43210),
    UL64(0xB00327C898FB213F),  UL64(0xBF597FC7BEEF0EE4),
    UL64(0xC6E00BF33DA88FC2),  UL64(0xD5A79147930AA725),
    UL64(0x06CA6351E003826F),  UL64(0x142929670A0E6E70),
    UL64(0x27B70A8546D22FFC),  UL64(0x2E1B21385C26C926),
    UL64(0x4D2C6DFC5AC42AED),  UL64(0x53380D139D95B3DF),
    UL64(0x650A73548BAF63DE),  UL64(0x766A0ABB3C77B2A8),
    UL64(0x81C2C92E47EDAEE6),  UL64(0x92722C851482353B),
    UL64(0xA2BFE8A14CF10364),  UL64(0xA81A664BBC423001),
    UL64(0xC24B8B70D0F89791),  UL64(0xC76C51A30654BE30),
    UL64(0xD192E819D6EF5218),  UL64(0xD69906245565A910),
    UL64(0xF40E35855771202A),  UL64(0x106AA07032BBD1B8),
    UL64(0x19A4C116B8D2D0C8),  UL64(0x1E376C085141AB53),
    UL64(0x2748774CDF8EEB99),  UL64(0x34B0BCB5E19B48A8),
    UL64(0x391C0CB3C5C95A63),  UL64(0x4ED8AA4AE3418ACB),
    UL64(0x5B9CCA4F7763E373),  UL64(0x682E6FF3D6B2B8A3),
    UL64(0x748F82EE5DEFB2FC),  UL64(0x78A5636F43172F60),
    UL64(0x84C87814A1F0AB72),  UL64(0x8CC702081A6439EC),
    UL64(0x90BEFFFA23631E28),  UL64(0xA4506CEBDE82BDE9),
    UL64(0xBEF9A3F7B2C67915),  UL64(0xC67178F2E372532B),
    UL64(0xCA273ECEEA26619C),  UL64(0xD186B8C721C0C207),
    UL64(0xEADA7DD6CDE0EB1E),  UL64(0xF57D4F7FEE6ED178),
    UL64(0x06F067AA72176FBA),  UL64(0x0A637DC5A2C898A6),
    UL64(0x113F9804BEF90DAE),  UL64(0x1B710B35131C471B),
    UL64(0x28DB77F523047D84),  UL64(0x32CAAB7B40C72493),
    UL64(0x3C9EBE0A15C9BEBC),  UL64(0x431D67C49C100D4C),
    UL64(0x4CC5D4BECB3E42B6),  UL64(0x597F299CFC657E2A),
    UL64(0x5FCB6FAB3AD6FAEC),  UL64(0x6C44198C4A475817)
};

static void mbedtls_sha512_software_process( mbedtls_sha512_context *ctx, const unsigned char data[128] );

int mbedtls_internal_sha512_process( mbedtls_sha512_context *ctx, const unsigned char data[128] )
{
    bool first_block = false;

    if (ctx->mode == ESP_MBEDTLS_SHA512_UNUSED) {
        /* try to use hardware for this digest */
        if (esp_sha_try_lock_engine(sha_type(ctx))) {
            ctx->mode = ESP_MBEDTLS_SHA512_HARDWARE;
            first_block = true;
        } else {
            ctx->mode = ESP_MBEDTLS_SHA512_SOFTWARE;
        }
    }

    if (ctx->mode == ESP_MBEDTLS_SHA512_HARDWARE) {
        esp_sha_block(sha_type(ctx), data, first_block);
    } else {
        mbedtls_sha512_software_process(ctx, data);
    }

    return 0;
}

static void mbedtls_sha512_software_process( mbedtls_sha512_context *ctx, const unsigned char data[128] )
{
    int i;
    uint64_t temp1, temp2, W[80];
    uint64_t A, B, C, D, E, F, G, H;

#define  SHR(x,n) (x >> n)
#define ROTR(x,n) (SHR(x,n) | (x << (64 - n)))

#define S0(x) (ROTR(x, 1) ^ ROTR(x, 8) ^  SHR(x, 7))
#define S1(x) (ROTR(x,19) ^ ROTR(x,61) ^  SHR(x, 6))

#define S2(x) (ROTR(x,28) ^ ROTR(x,34) ^ ROTR(x,39))
#define S3(x) (ROTR(x,14) ^ ROTR(x,18) ^ ROTR(x,41))

#define F0(x,y,z) ((x & y) | (z & (x | y)))
#define F1(x,y,z) (z ^ (x & (y ^ z)))

#define P(a,b,c,d,e,f,g,h,x,K)                  \
{                                               \
    temp1 = h + S3(e) + F1(e,f,g) + K + x;      \
    temp2 = S2(a) + F0(a,b,c);                  \
    d += temp1; h = temp1 + temp2;              \
}

    for ( i = 0; i < 16; i++ ) {
        GET_UINT64_BE( W[i], data, i << 3 );
    }

    for ( ; i < 80; i++ ) {
        W[i] = S1(W[i -  2]) + W[i -  7] +
               S0(W[i - 15]) + W[i - 16];
    }

    A = ctx->state[0];
    B = ctx->state[1];
    C = ctx->state[2];
    D = ctx->state[3];
    E = ctx->state[4];
    F = ctx->state[5];
    G = ctx->state[6];
    H = ctx->state[7];
    i = 0;

    do {
        P( A, B, C, D, E, F, G, H, W[i], K[i] ); i++;
        P( H, A, B, C, D, E, F, G, W[i], K[i] ); i++;
        P( G, H, A, B, C, D, E, F, W[i], K[i] ); i++;
        P( F, G, H, A, B, C, D, E, W[i], K[i] ); i++;
        P( E, F, G, H, A, B, C, D, W[i], K[i] ); i++;
        P( D, E, F, G, H, A, B, C, W[i], K[i] ); i++;
        P( C, D, E, F, G, H, A, B, W[i], K[i] ); i++;
        P( B, C, D, E, F, G, H, A, W[i], K[i] ); i++;
    } while ( i < 80 );

    ctx->state[0] += A;
    ctx->state[1] += B;
    ctx->state[2] += C;
    ctx->state[3] += D;
    ctx->state[4] += E;
    ctx->state[5] += F;
    ctx->state[6] += G;
    ctx->state[7] += H;
}

/*
 * 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;

    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 );
        if ( ( ret = mbedtls_internal_sha512_process( ctx, ctx->buffer ) ) != 0 ) {
            return ret;
        }

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

    while ( ilen >= 128 ) {
        if ( ( ret = mbedtls_internal_sha512_process( ctx, input ) ) != 0 ) {
            return ret;
        }

        input += 128;
        ilen  -= 128;
    }

    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;
    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 ) {
        goto out;
    }

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

    /* if state is in hardware, read it out */
    if (ctx->mode == ESP_MBEDTLS_SHA512_HARDWARE) {
        esp_sha_read_digest_state(sha_type(ctx), ctx->state);
    }

    PUT_UINT64_BE( ctx->state[0], output,  0 );
    PUT_UINT64_BE( ctx->state[1], output,  8 );
    PUT_UINT64_BE( ctx->state[2], output, 16 );
    PUT_UINT64_BE( ctx->state[3], output, 24 );
    PUT_UINT64_BE( ctx->state[4], output, 32 );
    PUT_UINT64_BE( ctx->state[5], output, 40 );

    if ( ctx->is384 == 0 ) {
        PUT_UINT64_BE( ctx->state[6], output, 48 );
        PUT_UINT64_BE( ctx->state[7], output, 56 );
    }

out:
    if (ctx->mode == ESP_MBEDTLS_SHA512_HARDWARE) {
        esp_sha_unlock_engine(sha_type(ctx));
        ctx->mode = ESP_MBEDTLS_SHA512_SOFTWARE;
    }

    return ret;
}

#endif /* MBEDTLS_SHA512_C && MBEDTLS_SHA512_ALT */