g_eli_crypto_hmac_init
g_eli_crypto_hmac_init(ctx, NULL, 0);
g_eli_crypto_hmac_init(&ctx, NULL, 0);
g_eli_crypto_hmac_init(&ctx, NULL, 0);
void g_eli_crypto_hmac_init(struct hmac_ctx *ctx, const char *hkey,
g_eli_crypto_hmac_init(&ctx, hkey, hkeysize);
g_eli_crypto_hmac_init(&startpoint, passphrase, passlen);