if C._goboringcrypto_HMAC_Init(&h.ctx, unsafe.Pointer(base(h.key)), C.int(len(h.key)), h.md) == 0 {
		panic("boringcrypto: HMAC_Init failed")
	}
	if int(C._goboringcrypto_HMAC_size(&h.ctx)) != h.size {
		println("boringcrypto: HMAC size:", C._goboringcrypto_HMAC_size(&h.ctx), "!=", h.size)
		panic("boringcrypto: HMAC size mismatch")
	}
	runtime.KeepAlive(h) // Next line will keep h alive too; just making doubly sure.
	h.sum = nil

int _goboringcrypto_HMAC_Update(GO_HMAC_CTX*, const uint8_t*, size_t);
int _goboringcrypto_HMAC_Final(GO_HMAC_CTX*, uint8_t*, unsigned int*);
size_t _goboringcrypto_HMAC_size(const GO_HMAC_CTX*);
int _goboringcrypto_HMAC_CTX_copy_ex(GO_HMAC_CTX *dest, const GO_HMAC_CTX *src);

// #include <openssl/aes.h>
typedef struct GO_AES_KEY { char data[244]; } GO_AES_KEY;