#include <string.h>

#include "crypto_box.h"

#include "crypto_generichash.h"

#include "private/common.h"

#include "utils.h"

static int

_crypto_box_seal_nonce(unsigned char *nonce,

                       const unsigned char *pk1, const unsigned char *pk2)

{

    crypto_generichash_state st;

    crypto_generichash_init(&st, NULL, 0U, crypto_box_NONCEBYTES);

    crypto_generichash_update(&st, pk1, crypto_box_PUBLICKEYBYTES);

    crypto_generichash_update(&st, pk2, crypto_box_PUBLICKEYBYTES);

    crypto_generichash_final(&st, nonce, crypto_box_NONCEBYTES);

    return 0;

}

int

crypto_box_seal(unsigned char *c, const unsigned char *m,

                unsigned long long mlen, const unsigned char *pk)

{

    unsigned char nonce[crypto_box_NONCEBYTES];

    unsigned char epk[crypto_box_PUBLICKEYBYTES];

    unsigned char esk[crypto_box_SECRETKEYBYTES];

    int           ret;

    if (crypto_box_keypair(epk, esk) != 0) {

        return -1; /* LCOV_EXCL_LINE */

    }

    memcpy(c, epk, crypto_box_PUBLICKEYBYTES);

    _crypto_box_seal_nonce(nonce, epk, pk);

    ret = crypto_box_easy(c + crypto_box_PUBLICKEYBYTES, m, mlen,

                          nonce, pk, esk);

    sodium_memzero(esk, sizeof esk);

    sodium_memzero(epk, sizeof epk);

    sodium_memzero(nonce, sizeof nonce);

    return ret;

}

int

crypto_box_seal_open(unsigned char *m, const unsigned char *c,

                     unsigned long long clen,

                     const unsigned char *pk, const unsigned char *sk)

{

    unsigned char nonce[crypto_box_NONCEBYTES];

    if (clen < crypto_box_SEALBYTES) {

        return -1;

    }

    _crypto_box_seal_nonce(nonce, c, pk);

    COMPILER_ASSERT(crypto_box_PUBLICKEYBYTES < crypto_box_SEALBYTES);

    return crypto_box_open_easy(m, c + crypto_box_PUBLICKEYBYTES,

                                clen - crypto_box_PUBLICKEYBYTES,

                                nonce, c, sk);

}

size_t

crypto_box_sealbytes(void)

{

    return crypto_box_SEALBYTES;

}