Golang CK_GCM_PARAMS

gcm_params.go

package main

/*
#include <stdio.h>
#include <stdlib.h>
#define CK_BYTE_PTR unsigned char *
#define CK_ULONG unsigned long long
typedef struct CK_GCM_PARAMS {
  CK_BYTE_PTR pIv;
  CK_ULONG ulIvLen;
  CK_ULONG ulIvBits;
  CK_BYTE_PTR pAAD;
  CK_ULONG ulAADLen;
  CK_ULONG ulTagBits;
} CK_GCM_PARAMS;
#define CK_GCM_PARAMS_SIZE sizeof(CK_GCM_PARAMS)
*/
import "C"
import "unsafe"

func gcmParamBytes(iv []byte) (paramBytes []byte, free func()) {
	ivBytes := C.CBytes(iv)
	free = func() {
		C.free(ivBytes)
	}

	params := C.CK_GCM_PARAMS{
		pIv:       C.CK_BYTE_PTR(ivBytes),
		ulIvLen:   C.CK_ULONG(len(iv)),
		ulIvBits:  C.CK_ULONG(len(iv) * 8),
		ulTagBits: C.CK_ULONG(128),
	}

	paramBytes = C.GoBytes(unsafe.Pointer(&params), C.CK_GCM_PARAMS_SIZE)

	return
}

func gcmParamsFromBytes(paramBytes []byte) (iv []byte, ivLen int, ivBits int, tagBits int) {
	paramBytesPtr := C.CBytes(paramBytes)
	defer C.free(paramBytesPtr)

	params := (*C.CK_GCM_PARAMS)(paramBytesPtr)

	ivLen = int(params.ulIvLen)
	ivBits = int(params.ulIvBits)
	tagBits = int(params.ulTagBits)
	iv = C.GoBytes(unsafe.Pointer(params.pIv), C.int(ivLen))

	return
}