#include <limits.h>

#include <stdint.h>

#include <stdlib.h>

#include <string.h>

#include "crypto_generichash_blake2b.h"

#include "private/common.h"

#include "utils.h"

#include "blake2b-long.h"

int

blake2b_long(void *pout, size_t outlen, const void *in, size_t inlen)

{

    uint8_t *out = (uint8_t *) pout;

    crypto_generichash_blake2b_state blake_state;

    uint8_t outlen_bytes[4 /* sizeof(uint32_t) */] = { 0 };

    int     ret = -1;

    if (outlen > UINT32_MAX) {

        goto fail; /* LCOV_EXCL_LINE */

    }

    /* Ensure little-endian byte order! */

    STORE32_LE(outlen_bytes, (uint32_t) outlen);

#define TRY(statement)   \

    do {                 \

        ret = statement; \

        if (ret < 0) {   \

            goto fail;   \

        }                \

    } while ((void) 0, 0)

    if (outlen <= crypto_generichash_blake2b_BYTES_MAX) {

        TRY(crypto_generichash_blake2b_init(&blake_state, NULL, 0U, outlen));

        TRY(crypto_generichash_blake2b_update(&blake_state, outlen_bytes,

                                              sizeof(outlen_bytes)));

        TRY(crypto_generichash_blake2b_update(

            &blake_state, (const unsigned char *) in, inlen));

        TRY(crypto_generichash_blake2b_final(&blake_state, out, outlen));

    } else {

        uint32_t toproduce;

        uint8_t  out_buffer[crypto_generichash_blake2b_BYTES_MAX];

        uint8_t  in_buffer[crypto_generichash_blake2b_BYTES_MAX];

        TRY(crypto_generichash_blake2b_init(

            &blake_state, NULL, 0U, crypto_generichash_blake2b_BYTES_MAX));

        TRY(crypto_generichash_blake2b_update(&blake_state, outlen_bytes,

                                              sizeof(outlen_bytes)));

        TRY(crypto_generichash_blake2b_update(

            &blake_state, (const unsigned char *) in, inlen));

        TRY(crypto_generichash_blake2b_final(

            &blake_state, out_buffer, crypto_generichash_blake2b_BYTES_MAX));

        memcpy(out, out_buffer, crypto_generichash_blake2b_BYTES_MAX / 2);

        out += crypto_generichash_blake2b_BYTES_MAX / 2;

        toproduce =

            (uint32_t) outlen - crypto_generichash_blake2b_BYTES_MAX / 2;

        while (toproduce > crypto_generichash_blake2b_BYTES_MAX) {

            memcpy(in_buffer, out_buffer, crypto_generichash_blake2b_BYTES_MAX);

            TRY(crypto_generichash_blake2b(

                out_buffer, crypto_generichash_blake2b_BYTES_MAX, in_buffer,

                crypto_generichash_blake2b_BYTES_MAX, NULL, 0U));

            memcpy(out, out_buffer, crypto_generichash_blake2b_BYTES_MAX / 2);

            out += crypto_generichash_blake2b_BYTES_MAX / 2;

            toproduce -= crypto_generichash_blake2b_BYTES_MAX / 2;

        }

        memcpy(in_buffer, out_buffer, crypto_generichash_blake2b_BYTES_MAX);

        TRY(crypto_generichash_blake2b(out_buffer, toproduce, in_buffer,

                                       crypto_generichash_blake2b_BYTES_MAX,

                                       NULL, 0U));

        memcpy(out, out_buffer, toproduce);

    }

fail:

    sodium_memzero(&blake_state, sizeof(blake_state));

    return ret;

#undef TRY

}