/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:4;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright The Mbed TLS Contributors                                          │
│                                                                              │
│ Licensed under the Apache License, Version 2.0 (the "License");              │
│ you may not use this file except in compliance with the License.             │
│ You may obtain a copy of the License at                                      │
│                                                                              │
│     http://www.apache.org/licenses/LICENSE-2.0                               │
│                                                                              │
│ Unless required by applicable law or agreed to in writing, software          │
│ distributed under the License is distributed on an "AS IS" BASIS,            │
│ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.     │
│ See the License for the specific language governing permissions and          │
│ limitations under the License.                                               │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "third_party/mbedtls/sha256.h"
#include "libc/dce.h"
#include "libc/macros.h"
#include "libc/nexgen32e/nexgen32e.h"
#include "libc/nexgen32e/sha.h"
#include "libc/nexgen32e/x86feature.h"
#include "libc/str/str.h"
#include "third_party/mbedtls/common.h"
#include "third_party/mbedtls/endian.h"
#include "third_party/mbedtls/error.h"
#include "third_party/mbedtls/md.h"
__static_yoink("mbedtls_notice");

/**
 * @fileoverview FIPS-180-2 compliant SHA-256 implementation
 *
 * The SHA-256 Secure Hash Standard was published by NIST in 2002.
 *
 * @see http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
 */

#define SHA256_VALIDATE_RET(cond)                           \
    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_SHA256_BAD_INPUT_DATA )
#define SHA256_VALIDATE(cond)  MBEDTLS_INTERNAL_VALIDATE( cond )

#if !defined(MBEDTLS_SHA256_ALT)

/**
 * \brief          This function clones the state of a SHA-256 context.
 *
 * \param dst      The destination context. This must be initialized.
 * \param src      The context to clone. This must be initialized.
 */
void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
                           const mbedtls_sha256_context *src )
{
    SHA256_VALIDATE( dst );
    SHA256_VALIDATE( src );
    *dst = *src;
}

int mbedtls_sha256_starts_224( mbedtls_sha256_context *ctx )
{
    SHA256_VALIDATE_RET( ctx );
    ctx->total[0] = 0;
    ctx->total[1] = 0;
    ctx->state[0] = 0xC1059ED8;
    ctx->state[1] = 0x367CD507;
    ctx->state[2] = 0x3070DD17;
    ctx->state[3] = 0xF70E5939;
    ctx->state[4] = 0xFFC00B31;
    ctx->state[5] = 0x68581511;
    ctx->state[6] = 0x64F98FA7;
    ctx->state[7] = 0xBEFA4FA4;
    ctx->is224 = true;
    return( 0 );
}

int mbedtls_sha256_starts_256( mbedtls_sha256_context *ctx )
{
    SHA256_VALIDATE_RET( ctx );
    ctx->total[0] = 0;
    ctx->total[1] = 0;
    ctx->state[0] = 0x6A09E667;
    ctx->state[1] = 0xBB67AE85;
    ctx->state[2] = 0x3C6EF372;
    ctx->state[3] = 0xA54FF53A;
    ctx->state[4] = 0x510E527F;
    ctx->state[5] = 0x9B05688C;
    ctx->state[6] = 0x1F83D9AB;
    ctx->state[7] = 0x5BE0CD19;
    ctx->is224 = false;
    return( 0 );
}

/**
 * \brief          This function starts a SHA-224 or SHA-256 checksum
 *                 calculation.
 *
 * \param ctx      The context to use. This must be initialized.
 * \param is224    This determines which function to use. This must be
 *                 either \c 0 for SHA-256, or \c 1 for SHA-224.
 *
 * \return         \c 0 on success.
 * \return         A negative error code on failure.
 */
int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 )
{
    SHA256_VALIDATE_RET( ctx );
    SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
    if( !is224 )
        return mbedtls_sha256_starts_256( ctx );
    else
        return mbedtls_sha256_starts_224( ctx );
}

#if !defined(MBEDTLS_SHA256_PROCESS_ALT)
#define K kSha256

#define  SHR(x,n) (((x) & 0xFFFFFFFF) >> (n))
#define ROTR(x,n) (SHR(x,n) | ((x) << (32 - (n))))

#define S0(x) (ROTR(x, 7) ^ ROTR(x,18) ^  SHR(x, 3))
#define S1(x) (ROTR(x,17) ^ ROTR(x,19) ^  SHR(x,10))

#define S2(x) (ROTR(x, 2) ^ ROTR(x,13) ^ ROTR(x,22))
#define S3(x) (ROTR(x, 6) ^ ROTR(x,11) ^ ROTR(x,25))

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

#define R(t)                                                        \
    (                                                               \
        local.W[t] = S1(local.W[(t) -  2]) + local.W[(t) -  7] +    \
                     S0(local.W[(t) - 15]) + local.W[(t) - 16]      \
    )

#define P(a,b,c,d,e,f,g,h,x,K)                                      \
    do                                                              \
    {                                                               \
        local.temp1 = (h) + S3(e) + F1((e),(f),(g)) + (K) + (x);    \
        local.temp2 = S2(a) + F0((a),(b),(c));                      \
        (d) += local.temp1; (h) = local.temp1 + local.temp2;        \
    } while( 0 )

/**
 * \brief          This function processes a single data block within
 *                 the ongoing SHA-256 computation. This function is for
 *                 internal use only.
 *
 * \param ctx      The SHA-256 context. This must be initialized.
 * \param data     The buffer holding one block of data. This must
 *                 be a readable buffer of length \c 64 Bytes.
 *
 * \return         \c 0 on success.
 * \return         A negative error code on failure.
 */
int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
                                     const unsigned char data[64] )
{
    struct
    {
        uint32_t temp1, temp2, W[64];
        uint32_t A[8];
    } local;
    unsigned int i;

    SHA256_VALIDATE_RET( ctx != NULL );
    SHA256_VALIDATE_RET( (const unsigned char *)data != NULL );

    if( X86_HAVE( SHA ) &&
        X86_HAVE( SSE2 ) &&
        X86_HAVE( SSSE3 ) )
    {
        sha256_transform_ni( ctx->state, data, 1 );
        return( 0 );
    }
    if( X86_HAVE( BMI2 ) &&
        X86_HAVE( AVX  ) &&
        X86_HAVE( AVX2 ) )
    {
        sha256_transform_rorx( ctx->state, data, 1 );
        return( 0 );
    }

    for( i = 0; i < 8; i++ )
        local.A[i] = ctx->state[i];

#if defined(MBEDTLS_SHA256_SMALLER)
    for( i = 0; i < 64; i++ ) {
        if( i < 16 )
            GET_UINT32_BE( local.W[i], data, 4 * i );
        else
            R( i );
        P( local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
           local.A[5], local.A[6], local.A[7], local.W[i], K[i] );
        local.temp1 = local.A[7]; local.A[7] = local.A[6];
        local.A[6] = local.A[5]; local.A[5] = local.A[4];
        local.A[4] = local.A[3]; local.A[3] = local.A[2];
        local.A[2] = local.A[1]; local.A[1] = local.A[0];
        local.A[0] = local.temp1;
    }
#else /* MBEDTLS_SHA256_SMALLER */
    for( i = 0; i < 16; i++ )
        GET_UINT32_BE( local.W[i], data, 4 * i );
    for( i = 0; i < 16; i += 8 ) {
        P( local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
           local.A[5], local.A[6], local.A[7], local.W[i+0], K[i+0] );
        P( local.A[7], local.A[0], local.A[1], local.A[2], local.A[3],
           local.A[4], local.A[5], local.A[6], local.W[i+1], K[i+1] );
        P( local.A[6], local.A[7], local.A[0], local.A[1], local.A[2],
           local.A[3], local.A[4], local.A[5], local.W[i+2], K[i+2] );
        P( local.A[5], local.A[6], local.A[7], local.A[0], local.A[1],
           local.A[2], local.A[3], local.A[4], local.W[i+3], K[i+3] );
        P( local.A[4], local.A[5], local.A[6], local.A[7], local.A[0],
           local.A[1], local.A[2], local.A[3], local.W[i+4], K[i+4] );
        P( local.A[3], local.A[4], local.A[5], local.A[6], local.A[7],
           local.A[0], local.A[1], local.A[2], local.W[i+5], K[i+5] );
        P( local.A[2], local.A[3], local.A[4], local.A[5], local.A[6],
           local.A[7], local.A[0], local.A[1], local.W[i+6], K[i+6] );
        P( local.A[1], local.A[2], local.A[3], local.A[4], local.A[5],
           local.A[6], local.A[7], local.A[0], local.W[i+7], K[i+7] );
    }
    for( i = 16; i < 64; i += 8 ) {
        P( local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
           local.A[5], local.A[6], local.A[7], R(i+0), K[i+0] );
        P( local.A[7], local.A[0], local.A[1], local.A[2], local.A[3],
           local.A[4], local.A[5], local.A[6], R(i+1), K[i+1] );
        P( local.A[6], local.A[7], local.A[0], local.A[1], local.A[2],
           local.A[3], local.A[4], local.A[5], R(i+2), K[i+2] );
        P( local.A[5], local.A[6], local.A[7], local.A[0], local.A[1],
           local.A[2], local.A[3], local.A[4], R(i+3), K[i+3] );
        P( local.A[4], local.A[5], local.A[6], local.A[7], local.A[0],
           local.A[1], local.A[2], local.A[3], R(i+4), K[i+4] );
        P( local.A[3], local.A[4], local.A[5], local.A[6], local.A[7],
           local.A[0], local.A[1], local.A[2], R(i+5), K[i+5] );
        P( local.A[2], local.A[3], local.A[4], local.A[5], local.A[6],
           local.A[7], local.A[0], local.A[1], R(i+6), K[i+6] );
        P( local.A[1], local.A[2], local.A[3], local.A[4], local.A[5],
           local.A[6], local.A[7], local.A[0], R(i+7), K[i+7] );
    }
#endif /* MBEDTLS_SHA256_SMALLER */

    for( i = 0; i < 8; i++ )
        ctx->state[i] += local.A[i];

    /* Zeroise buffers and variables to clear sensitive data from memory. */
    mbedtls_platform_zeroize( &local, sizeof( local ) );

    return( 0 );
}

#endif /* !MBEDTLS_SHA256_PROCESS_ALT */

/**
 * \brief          This function feeds an input buffer into an ongoing
 *                 SHA-256 checksum calculation.
 *
 * \param ctx      The SHA-256 context. This must be initialized
 *                 and have a hash operation started.
 * \param input    The buffer holding the data. This must be a readable
 *                 buffer of length \p ilen Bytes.
 * \param ilen     The length of the input data in Bytes.
 *
 * \return         \c 0 on success.
 * \return         A negative error code on failure.
 */
int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
                               const unsigned char *input,
                               size_t ilen )
{
    int ret = MBEDTLS_ERR_THIS_CORRUPTION;
    size_t fill;
    uint32_t left;

    SHA256_VALIDATE_RET( ctx != NULL );
    SHA256_VALIDATE_RET( ilen == 0 || input != NULL );

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

    left = ctx->total[0] & 0x3F;
    fill = 64 - left;

    ctx->total[0] += (uint32_t) ilen;
    ctx->total[0] &= 0xFFFFFFFF;

    if( ctx->total[0] < (uint32_t) ilen )
        ctx->total[1]++;

    if( left && ilen >= fill )
    {
        memcpy( (void *) (ctx->buffer + left), input, fill );
        if( ( ret = mbedtls_internal_sha256_process( ctx, ctx->buffer ) ) != 0 )
            return( ret );
        input += fill;
        ilen  -= fill;
        left = 0;
    }

    if( ilen >= 64 )
    {
        if( X86_HAVE( SHA ) &&
            X86_HAVE( SSE2 ) &&
            X86_HAVE( SSSE3 ) )
        {
            sha256_transform_ni( ctx->state, input, ilen / 64 );
            input += ROUNDDOWN( ilen, 64 );
            ilen  -= ROUNDDOWN( ilen, 64 );
        }
        else if( X86_HAVE( BMI  ) &&
                 X86_HAVE( BMI2 ) &&
                 X86_HAVE( AVX2 ) )
        {
            sha256_transform_rorx( ctx->state, input, ilen / 64 );
            input += ROUNDDOWN( ilen, 64 );
            ilen  -= ROUNDDOWN( ilen, 64 );
        }
        else
        {
            do
            {
                if(( ret = mbedtls_internal_sha256_process( ctx, input ) ))
                    return( ret );
                input += 64;
                ilen  -= 64;
            }
            while( ilen >= 64 );
        }
    }

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

    return( 0 );
}

/**
 * \brief          This function finishes the SHA-256 operation, and writes
 *                 the result to the output buffer.
 *
 * \param ctx      The SHA-256 context. This must be initialized
 *                 and have a hash operation started.
 * \param output   The SHA-224 or SHA-256 checksum result.
 *                 This must be a writable buffer of length \c 32 Bytes.
 *
 * \return         \c 0 on success.
 * \return         A negative error code on failure.
 */
int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
                               unsigned char output[32] )
{
    int ret = MBEDTLS_ERR_THIS_CORRUPTION;
    uint32_t used;
    uint32_t high, low;

    SHA256_VALIDATE_RET( ctx != NULL );
    SHA256_VALIDATE_RET( (unsigned char *)output != NULL );

    /*
     * Add padding: 0x80 then 0x00 until 8 bytes remain for the length
     */
    used = ctx->total[0] & 0x3F;

    ctx->buffer[used++] = 0x80;

    if( used <= 56 )
    {
        /* Enough room for padding + length in current block */
        mbedtls_platform_zeroize( ctx->buffer + used, 56 - used );
    }
    else
    {
        /* We'll need an extra block */
        mbedtls_platform_zeroize( ctx->buffer + used, 64 - used );

        if( ( ret = mbedtls_internal_sha256_process( ctx, ctx->buffer ) ) != 0 )
            return( ret );

        mbedtls_platform_zeroize( ctx->buffer, 56 );
    }

    /*
     * Add message length
     */
    high = ( ctx->total[0] >> 29 )
         | ( ctx->total[1] <<  3 );
    low  = ( ctx->total[0] <<  3 );

    PUT_UINT32_BE( high, ctx->buffer, 56 );
    PUT_UINT32_BE( low,  ctx->buffer, 60 );

    if( ( ret = mbedtls_internal_sha256_process( ctx, ctx->buffer ) ) != 0 )
        return( ret );

    /*
     * Output final state
     */
    PUT_UINT32_BE( ctx->state[0], output,  0 );
    PUT_UINT32_BE( ctx->state[1], output,  4 );
    PUT_UINT32_BE( ctx->state[2], output,  8 );
    PUT_UINT32_BE( ctx->state[3], output, 12 );
    PUT_UINT32_BE( ctx->state[4], output, 16 );
    PUT_UINT32_BE( ctx->state[5], output, 20 );
    PUT_UINT32_BE( ctx->state[6], output, 24 );

    if( ctx->is224 == 0 )
        PUT_UINT32_BE( ctx->state[7], output, 28 );

    return( 0 );
}

#endif /* !MBEDTLS_SHA256_ALT */

/**
 * \brief          This function calculates the SHA-224 or SHA-256
 *                 checksum of a buffer.
 *
 *                 The function allocates the context, performs the
 *                 calculation, and frees the context.
 *
 *                 The SHA-256 result is calculated as
 *                 output = SHA-256(input buffer).
 *
 * \param input    The buffer holding the data. This must be a readable
 *                 buffer of length \p ilen Bytes.
 * \param ilen     The length of the input data in Bytes.
 * \param output   The SHA-224 or SHA-256 checksum result. This must
 *                 be a writable buffer of length \c 32 Bytes.
 * \param is224    Determines which function to use. This must be
 *                 either \c 0 for SHA-256, or \c 1 for SHA-224.
 */
int mbedtls_sha256_ret( const void *input,
                        size_t ilen,
                        unsigned char output[32],
                        int is224 )
{
    int ret = MBEDTLS_ERR_THIS_CORRUPTION;
    mbedtls_sha256_context ctx;

    SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
    SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
    SHA256_VALIDATE_RET( (unsigned char *)output != NULL );

    mbedtls_sha256_init( &ctx );

    if( ( ret = mbedtls_sha256_starts_ret( &ctx, is224 ) ) != 0 )
        goto exit;

    if( ( ret = mbedtls_sha256_update_ret( &ctx, input, ilen ) ) != 0 )
        goto exit;

    if( ( ret = mbedtls_sha256_finish_ret( &ctx, output ) ) != 0 )
        goto exit;

exit:
    mbedtls_sha256_free( &ctx );

    return( ret );
}

dontinstrument int mbedtls_sha256_ret_224( const void *input, size_t ilen, unsigned char *output )
{
    return mbedtls_sha256_ret( input, ilen, output, true );
}

dontinstrument int mbedtls_sha256_ret_256( const void *input, size_t ilen, unsigned char *output )
{
    return mbedtls_sha256_ret( input, ilen, output, false );
}

const mbedtls_md_info_t mbedtls_sha224_info = {
    "SHA224",
    MBEDTLS_MD_SHA224,
    28,
    64,
    (void *)mbedtls_sha256_starts_224,
    (void *)mbedtls_sha256_update_ret,
    (void *)mbedtls_internal_sha256_process,
    (void *)mbedtls_sha256_finish_ret,
    mbedtls_sha256_ret_224,
};

const mbedtls_md_info_t mbedtls_sha256_info = {
    "SHA256",
    MBEDTLS_MD_SHA256,
    32,
    64,
    (void *)mbedtls_sha256_starts_256,
    (void *)mbedtls_sha256_update_ret,
    (void *)mbedtls_internal_sha256_process,
    (void *)mbedtls_sha256_finish_ret,
    mbedtls_sha256_ret_256,
};