Iterate C array struct in Go - c

Question

package main
//#cgo LDFLAGS: -ldl -lp11
//#include <stdlib.h>
//#include <libp11.h>
import "C"
import (
"log"
"unsafe"
"fmt"
//"runtime"
//"reflect"
)
func main(){
var ctx *C.PKCS11_CTX
ctx = C.PKCS11_CTX_new()
//log.Println(ctx)
cModulePath := C.CString("/home/procondutor/libaetpkss.so.3.0.3930")
defer C.free(unsafe.Pointer(cModulePath))
rc := C.PKCS11_CTX_load(ctx, cModulePath)
if rc < 0 {
log.Println("1 erro rc menor que 0")
return
}
var slots, slot *C.PKCS11_SLOT
var keys *C.PKCS11_KEY
var nslots, nkeys uint
p := unsafe.Pointer(&nslots)
n := unsafe.Pointer(&nkeys)
//log.Println(nkeys)
rc = C.PKCS11_enumerate_slots(ctx, &slots, (*C.uint)(p))
if rc < 0 {
log.Println("2 erro rc menor que 0")
return
}
slot = C.PKCS11_find_token(ctx, slots, C.uint(nslots));
s := C.GoString(slot.manufacturer)
fmt.Printf("%+v\n", s)
cPin := C.CString("2903")
defer C.free(unsafe.Pointer(cPin))
rc = C.PKCS11_login(slot, 0, cPin);
if rc < 0 {
log.Println("3 erro rc menor que 0")
return
}
rc = C.PKCS11_enumerate_keys(slot.token, &keys, (*C.uint)(n));
if rc < 0 {
log.Println("4 erro rc menor que 0")
return
}
My problem is in the PKCS11_enumerate_keys function, in C this function returns a list according to the code below:
static void list_keys(const char *title, const PKCS11_KEY *keys,
const unsigned int nkeys) {
unsigned int i;
printf("\n%s:\n", title);
for (i = 0; i < nkeys; i++)
printf(" * %s key: %s\n",
keys[i].isPrivate ? "Private" : "Public", keys[i].label);
}
But in Go it only returns the first object.
If I try to iterate in Go, I get the following error:
invalid operation: cannot index keys (variable of type *_Ctype_struct_PKCS11_key_st)

Answer 1

I finally got it with the code below:
list_keys := unsafe.Slice(keys, nkeys)
for i := 0; i < int(nkeys); i++ {
z:= C.GoString(slice[i].label)
fmt.Println(z)
}