linux-sgx-trts-modified/psw/ae/pve/endpoint_selection.cpp

/*
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#include "provision_msg.h"
#include <sgx_trts.h>
#include "protocol.h"
#include "helper.h"
#include "cipher.h"
#include <string.h>

//Function to generate 1 byte selector id for end point selection
//The End Point Selection is an optional protocol before SGX EPID Provisioning
//   to get the server address and expired date(of the server) for SGX EPID Provisioning
//   a one byte selector id is required for each machine which never changes for any machine
//   First byte of PPID is used currently as the selector id
static pve_status_t gen_es_selector_id(uint8_t *selector_id)
{
    ppid_t ppid;
    memset(&ppid, 0, sizeof(ppid));
    pve_status_t ret = get_ppid(&ppid);
    if(ret != PVEC_SUCCESS)
        return ret;

    *selector_id = ppid.ppid[0];
    (void)memset_s(&ppid, sizeof(ppid), 0, sizeof(ppid));//clear the PPID in stack
    return PVEC_SUCCESS;
}


//Function to generate End Point Selection id and XID for end point selection msg1
//@es_selector, output XID and SelectorID
//@return PVEC_SUCCESS on success or error code otherwise
pve_status_t gen_es_msg1_data(gen_endpoint_selection_output_t *es_selector)
{
    //randomly generate xid
    pve_status_t ret = se_read_rand_error_to_pve_error(sgx_read_rand(es_selector->xid, XID_SIZE));
    if(ret != PVEC_SUCCESS)
        return ret;
    //generate selector id which is hash value of Provisioning Base Key
    return gen_es_selector_id(&es_selector->selector_id);
}