static const size_t blklen = 128;
static bool hmac_sha512(const uint8_t *key, size_t keylen, const uint8_t *msg, size_t msglen, uint8_t *out) {
static const size_t blklen = 128;
static bool hmac_sha512(const uint8_t *key, size_t keylen, const uint8_t *msg, size_t msglen, uint8_t *out) {