#include <stdlib.h>
#include <sys/cdefs.h>
#include "esp_log.h"
#include "public.h"
#include "sdkconfig.h"


#include <stdlib.h>
#include <string.h>


#define SHA1_KEY_IOPAD_SIZE (64)
#define SHA1_DIGEST_SIZE    (20)

/* Implementation that should never be optimized out by the compiler */
static void utils_sha1_zeroize( void *v, uint32_t n ) {
    volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
}

/*
 * 32-bit integer manipulation macros (big endian)
 */
#ifndef GET_UINT32_BE
#define GET_UINT32_BE(n,b,i)                            \
{                                                       \
    (n) = ( (uint32_t) (b)[(i)    ] << 24 )             \
        | ( (uint32_t) (b)[(i) + 1] << 16 )             \
        | ( (uint32_t) (b)[(i) + 2] <<  8 )             \
        | ( (uint32_t) (b)[(i) + 3]       );            \
}
#endif

#ifndef PUT_UINT32_BE
#define PUT_UINT32_BE(n,b,i)                            \
{                                                       \
    (b)[(i)    ] = (unsigned char) ( (n) >> 24 );       \
    (b)[(i) + 1] = (unsigned char) ( (n) >> 16 );       \
    (b)[(i) + 2] = (unsigned char) ( (n) >>  8 );       \
    (b)[(i) + 3] = (unsigned char) ( (n)       );       \
}
#endif

void utils_sha1_init(iot_sha1_context *ctx)
{
    memset(ctx, 0, sizeof(iot_sha1_context));
}

void utils_sha1_free(iot_sha1_context *ctx)
{
    if (ctx == NULL) {
        return;
    }

    utils_sha1_zeroize(ctx, sizeof(iot_sha1_context));
}

void utils_sha1_clone(iot_sha1_context *dst,
                      const iot_sha1_context *src)
{
    *dst = *src;
}

/*
 * SHA-1 context setup
 */
void utils_sha1_starts(iot_sha1_context *ctx)
{
    ctx->total[0] = 0;
    ctx->total[1] = 0;

    ctx->state[0] = 0x67452301;
    ctx->state[1] = 0xEFCDAB89;
    ctx->state[2] = 0x98BADCFE;
    ctx->state[3] = 0x10325476;
    ctx->state[4] = 0xC3D2E1F0;
}

void utils_sha1_process(iot_sha1_context *ctx, const unsigned char data[64])
{
    uint32_t temp, W[16], A, B, C, D, E;

    GET_UINT32_BE( W[ 0], data,  0 );
    GET_UINT32_BE( W[ 1], data,  4 );
    GET_UINT32_BE( W[ 2], data,  8 );
    GET_UINT32_BE( W[ 3], data, 12 );
    GET_UINT32_BE( W[ 4], data, 16 );
    GET_UINT32_BE( W[ 5], data, 20 );
    GET_UINT32_BE( W[ 6], data, 24 );
    GET_UINT32_BE( W[ 7], data, 28 );
    GET_UINT32_BE( W[ 8], data, 32 );
    GET_UINT32_BE( W[ 9], data, 36 );
    GET_UINT32_BE( W[10], data, 40 );
    GET_UINT32_BE( W[11], data, 44 );
    GET_UINT32_BE( W[12], data, 48 );
    GET_UINT32_BE( W[13], data, 52 );
    GET_UINT32_BE( W[14], data, 56 );
    GET_UINT32_BE( W[15], data, 60 );

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

#define R(t)                                            \
(                                                       \
    temp = W[( t -  3 ) & 0x0F] ^ W[( t - 8 ) & 0x0F] ^ \
           W[( t - 14 ) & 0x0F] ^ W[  t       & 0x0F],  \
    ( W[t & 0x0F] = S(temp,1) )                         \
)

#define P(a,b,c,d,e,x)                                  \
{                                                       \
    e += S(a,5) + F(b,c,d) + K + x; b = S(b,30);        \
}

    A = ctx->state[0];
    B = ctx->state[1];
    C = ctx->state[2];
    D = ctx->state[3];
    E = ctx->state[4];

#define F(x,y,z) (z ^ (x & (y ^ z)))
#define K 0x5A827999

    P( A, B, C, D, E, W[0]  );
    P( E, A, B, C, D, W[1]  );
    P( D, E, A, B, C, W[2]  );
    P( C, D, E, A, B, W[3]  );
    P( B, C, D, E, A, W[4]  );
    P( A, B, C, D, E, W[5]  );
    P( E, A, B, C, D, W[6]  );
    P( D, E, A, B, C, W[7]  );
    P( C, D, E, A, B, W[8]  );
    P( B, C, D, E, A, W[9]  );
    P( A, B, C, D, E, W[10] );
    P( E, A, B, C, D, W[11] );
    P( D, E, A, B, C, W[12] );
    P( C, D, E, A, B, W[13] );
    P( B, C, D, E, A, W[14] );
    P( A, B, C, D, E, W[15] );
    P( E, A, B, C, D, R(16) );
    P( D, E, A, B, C, R(17) );
    P( C, D, E, A, B, R(18) );
    P( B, C, D, E, A, R(19) );

#undef K
#undef F

#define F(x,y,z) (x ^ y ^ z)
#define K 0x6ED9EBA1

    P( A, B, C, D, E, R(20) );
    P( E, A, B, C, D, R(21) );
    P( D, E, A, B, C, R(22) );
    P( C, D, E, A, B, R(23) );
    P( B, C, D, E, A, R(24) );
    P( A, B, C, D, E, R(25) );
    P( E, A, B, C, D, R(26) );
    P( D, E, A, B, C, R(27) );
    P( C, D, E, A, B, R(28) );
    P( B, C, D, E, A, R(29) );
    P( A, B, C, D, E, R(30) );
    P( E, A, B, C, D, R(31) );
    P( D, E, A, B, C, R(32) );
    P( C, D, E, A, B, R(33) );
    P( B, C, D, E, A, R(34) );
    P( A, B, C, D, E, R(35) );
    P( E, A, B, C, D, R(36) );
    P( D, E, A, B, C, R(37) );
    P( C, D, E, A, B, R(38) );
    P( B, C, D, E, A, R(39) );

#undef K
#undef F

#define F(x,y,z) ((x & y) | (z & (x | y)))
#define K 0x8F1BBCDC

    P( A, B, C, D, E, R(40) );
    P( E, A, B, C, D, R(41) );
    P( D, E, A, B, C, R(42) );
    P( C, D, E, A, B, R(43) );
    P( B, C, D, E, A, R(44) );
    P( A, B, C, D, E, R(45) );
    P( E, A, B, C, D, R(46) );
    P( D, E, A, B, C, R(47) );
    P( C, D, E, A, B, R(48) );
    P( B, C, D, E, A, R(49) );
    P( A, B, C, D, E, R(50) );
    P( E, A, B, C, D, R(51) );
    P( D, E, A, B, C, R(52) );
    P( C, D, E, A, B, R(53) );
    P( B, C, D, E, A, R(54) );
    P( A, B, C, D, E, R(55) );
    P( E, A, B, C, D, R(56) );
    P( D, E, A, B, C, R(57) );
    P( C, D, E, A, B, R(58) );
    P( B, C, D, E, A, R(59) );

#undef K
#undef F

#define F(x,y,z) (x ^ y ^ z)
#define K 0xCA62C1D6

    P( A, B, C, D, E, R(60) );
    P( E, A, B, C, D, R(61) );
    P( D, E, A, B, C, R(62) );
    P( C, D, E, A, B, R(63) );
    P( B, C, D, E, A, R(64) );
    P( A, B, C, D, E, R(65) );
    P( E, A, B, C, D, R(66) );
    P( D, E, A, B, C, R(67) );
    P( C, D, E, A, B, R(68) );
    P( B, C, D, E, A, R(69) );
    P( A, B, C, D, E, R(70) );
    P( E, A, B, C, D, R(71) );
    P( D, E, A, B, C, R(72) );
    P( C, D, E, A, B, R(73) );
    P( B, C, D, E, A, R(74) );
    P( A, B, C, D, E, R(75) );
    P( E, A, B, C, D, R(76) );
    P( D, E, A, B, C, R(77) );
    P( C, D, E, A, B, R(78) );
    P( B, C, D, E, A, R(79) );

#undef K
#undef F

    ctx->state[0] += A;
    ctx->state[1] += B;
    ctx->state[2] += C;
    ctx->state[3] += D;
    ctx->state[4] += E;
}

/*
 * SHA-1 process buffer
 */
void utils_sha1_update(iot_sha1_context *ctx, const unsigned char *input, uint32_t ilen)
{
    uint32_t fill;
    uint32_t left;

    if( ilen == 0 )
        return;

    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 );
        utils_sha1_process( ctx, ctx->buffer );
        input += fill;
        ilen  -= fill;
        left = 0;
    }

    while( ilen >= 64 )
    {
        utils_sha1_process( ctx, input );
        input += 64;
        ilen  -= 64;
    }

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

static const unsigned char sha1_padding[64] = {
 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
};

/*
 * SHA-1 final digest
 */
void utils_sha1_finish(iot_sha1_context *ctx, unsigned char output[20])
{
    uint32_t last, padn;
    uint32_t high, low;
    unsigned char msglen[8];

    high = ( ctx->total[0] >> 29 )
         | ( ctx->total[1] <<  3 );
    low  = ( ctx->total[0] <<  3 );

    PUT_UINT32_BE( high, msglen, 0 );
    PUT_UINT32_BE( low,  msglen, 4 );

    last = ctx->total[0] & 0x3F;
    padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );

    utils_sha1_update( ctx, sha1_padding, padn );
    utils_sha1_update( ctx, msglen, 8 );

    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 );
}


/*
 * output = SHA-1( input buffer )
 */
void utils_sha1(const unsigned char *input, uint32_t ilen, unsigned char output[20])
{
    iot_sha1_context ctx;

    utils_sha1_init(&ctx);
    utils_sha1_starts(&ctx);
    utils_sha1_update(&ctx, input, ilen);
    utils_sha1_finish(&ctx, output);
    utils_sha1_free(&ctx);
}

static int8_t utils_hb2hex(uint8_t hb)
{
    hb = hb & 0xF;
    return (int8_t)(hb < 10 ? '0' + hb : hb - 10 + 'a');
}

void utils_hmac_sha1(const char *msg, int msg_len, char *digest, const char *key, int key_len)
{
    iot_sha1_context context;
    unsigned char k_ipad[SHA1_KEY_IOPAD_SIZE];    /* inner padding - key XORd with ipad  */
    unsigned char k_opad[SHA1_KEY_IOPAD_SIZE];    /* outer padding - key XORd with opad */
    unsigned char out[SHA1_DIGEST_SIZE];
    int i;

    if ((NULL == msg) || (NULL == digest) || (NULL == key)) {
        return;
    }

    if (key_len > SHA1_KEY_IOPAD_SIZE) {
        return;
    }

    /* start out by storing key in pads */
    memset(k_ipad, 0, sizeof(k_ipad));
    memset(k_opad, 0, sizeof(k_opad));
    memcpy(k_ipad, key, key_len);
    memcpy(k_opad, key, key_len);

    /* XOR key with ipad and opad values */
    for (i = 0; i < SHA1_KEY_IOPAD_SIZE; i++) {
        k_ipad[i] ^= 0x36;
        k_opad[i] ^= 0x5c;
    }

    /* perform inner SHA */
    utils_sha1_init(&context);                                      /* init context for 1st pass */
    utils_sha1_starts(&context);                                    /* setup context for 1st pass */
    utils_sha1_update(&context, k_ipad, SHA1_KEY_IOPAD_SIZE);            /* start with inner pad */
    utils_sha1_update(&context, (unsigned char *) msg, msg_len);    /* then text of datagram */
    utils_sha1_finish(&context, out);                               /* finish up 1st pass */

    /* perform outer SHA */
    utils_sha1_init(&context);                              /* init context for 2nd pass */
    utils_sha1_starts(&context);                            /* setup context for 2nd pass */
    utils_sha1_update(&context, k_opad, SHA1_KEY_IOPAD_SIZE);    /* start with outer pad */
    utils_sha1_update(&context, out, SHA1_DIGEST_SIZE);     /* then results of 1st hash */
    utils_sha1_finish(&context, out);                       /* finish up 2nd pass */

    for (i = 0; i < SHA1_DIGEST_SIZE; ++i) {
        digest[i * 2] = utils_hb2hex(out[i] >> 4);
        digest[i * 2 + 1] = utils_hb2hex(out[i]);
    }
}

void utils_hmac_sha1_hex(const char *msg, int msg_len, char *digest, const char *key, int key_len)
{
    iot_sha1_context context;
    unsigned char k_ipad[SHA1_KEY_IOPAD_SIZE];    /* inner padding - key XORd with ipad  */
    unsigned char k_opad[SHA1_KEY_IOPAD_SIZE];    /* outer padding - key XORd with opad */
    unsigned char out[SHA1_DIGEST_SIZE];
    int i;

    if ((NULL == msg) || (NULL == digest) || (NULL == key)) {
        return;
    }

    if (key_len > SHA1_KEY_IOPAD_SIZE) {
        return;
    }

    /* start out by storing key in pads */
    memset(k_ipad, 0, sizeof(k_ipad));
    memset(k_opad, 0, sizeof(k_opad));
    memcpy(k_ipad, key, key_len);
    memcpy(k_opad, key, key_len);

    /* XOR key with ipad and opad values */
    for (i = 0; i < SHA1_KEY_IOPAD_SIZE; i++) {
        k_ipad[i] ^= 0x36;
        k_opad[i] ^= 0x5c;
    }

    /* perform inner SHA */
    utils_sha1_init(&context);                                      /* init context for 1st pass */
    utils_sha1_starts(&context);                                    /* setup context for 1st pass */
    utils_sha1_update(&context, k_ipad, SHA1_KEY_IOPAD_SIZE);            /* start with inner pad */
    utils_sha1_update(&context, (unsigned char *) msg, msg_len);    /* then text of datagram */
    utils_sha1_finish(&context, out);                               /* finish up 1st pass */

    /* perform outer SHA */
    utils_sha1_init(&context);                              /* init context for 2nd pass */
    utils_sha1_starts(&context);                            /* setup context for 2nd pass */
    utils_sha1_update(&context, k_opad, SHA1_KEY_IOPAD_SIZE);    /* start with outer pad */
    utils_sha1_update(&context, out, SHA1_DIGEST_SIZE);     /* then results of 1st hash */
    utils_sha1_finish(&context, out);                       /* finish up 2nd pass */
    memcpy(digest, out, SHA1_DIGEST_SIZE);
}