// that call must be followed by a call to runtime.KeepAlive(h),
		// to make sure h is not collected (and finalized) before the cgo
		// call returns.
		runtime.SetFinalizer(h, (*boringHMAC).finalize)
	}
	C._goboringcrypto_HMAC_CTX_init(&h.ctx)

	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")
	}

int _goboringcrypto_EVP_MD_type(const GO_EVP_MD*);
size_t _goboringcrypto_EVP_MD_size(const GO_EVP_MD*);

// #include <openssl/hmac.h>
typedef struct GO_HMAC_CTX { char data[104]; } GO_HMAC_CTX;
void _goboringcrypto_HMAC_CTX_init(GO_HMAC_CTX*);
void _goboringcrypto_HMAC_CTX_cleanup(GO_HMAC_CTX*);
int _goboringcrypto_HMAC_Init(GO_HMAC_CTX*, const void*, int, const GO_EVP_MD*);
int _goboringcrypto_HMAC_Update(GO_HMAC_CTX*, const uint8_t*, size_t);