#include <ngtcp2/ngtcp2_crypto.h>

int ngtcp2_crypto_hkdf_extract(uint8_t *dest, const ngtcp2_crypto_md *md, const uint8_t *secret, size_t secretlen, const uint8_t *salt, size_t saltlen)

ngtcp2_crypto_hkdf_extract() performs HKDF extract operation.

The length of output is ngtcp2_crypto_md_hashlen(md). The output is stored in the buffer pointed by dest. The caller is responsible to specify the buffer that has enough capacity to store the output.

This function returns 0 if it succeeds, or -1.