#include "pgsodium.h"

PG_FUNCTION_INFO_V1(pgsodium_crypto_kdf_keygen);
Datum pgsodium_crypto_kdf_keygen(PG_FUNCTION_ARGS) {
    size_t result_size = VARHDRSZ + crypto_kdf_KEYBYTES;
    bytea *result = _pgsodium_zalloc_bytea(result_size);
    crypto_kdf_keygen(PGSODIUM_UCHARDATA(result));
    PG_RETURN_BYTEA_P(result);
}

PG_FUNCTION_INFO_V1(pgsodium_crypto_kdf_derive_from_key);
Datum pgsodium_crypto_kdf_derive_from_key(PG_FUNCTION_ARGS) {
    size_t subkey_size = PG_GETARG_UINT32(0);
    size_t result_size = VARHDRSZ + subkey_size;
    unsigned long long subkey_id = PG_GETARG_INT64(1);
    bytea *context = PG_GETARG_BYTEA_P(2);
    bytea *primary_key = PG_GETARG_BYTEA_P(3);
    bytea *result;
    ERRORIF(VARSIZE_ANY_EXHDR(primary_key) != crypto_kdf_KEYBYTES,
            "%s: invalid derivation key");
    ERRORIF(subkey_size < crypto_kdf_BYTES_MIN ||
                subkey_size > crypto_kdf_BYTES_MAX,
            "%s: invalid key size requested");
    ERRORIF(VARSIZE_ANY_EXHDR(context) != 8,
            "%s: context must be 8 bytes");
    result = _pgsodium_zalloc_bytea(result_size);
    crypto_kdf_derive_from_key(PGSODIUM_UCHARDATA(result),
                               subkey_size,
                               subkey_id,
                               (const char *)VARDATA(context),
                               PGSODIUM_UCHARDATA(primary_key));
    PG_RETURN_BYTEA_P(result);
}