teems/Enclave/client.cpp

#include "Enclave_t.h"
#include "utils.hpp"
#include "client.hpp"

bool authenticateClient(unsigned char *auth_message,
    const sgx_aes_gcm_128bit_key_t *ckey)
{
    int auth_success = 0;
    unsigned long epoch_no = *((unsigned long*) auth_message);
    auth_message+=(sizeof(unsigned long));

    unsigned char computed_auth[SGX_AESGCM_KEY_SIZE];
    unsigned char zeroes[SGX_AESGCM_KEY_SIZE] = {0};
    unsigned char iv[SGX_AESGCM_IV_SIZE] = {0};
    sgx_aes_gcm_128bit_tag_t mac;
    memcpy(iv, &epoch_no, sizeof(epoch_no));
    sgx_status_t ret = SGX_SUCCESS;

    ret = sgx_rijndael128GCM_encrypt(ckey, zeroes, SGX_AESGCM_KEY_SIZE,
        computed_auth, iv, SGX_AESGCM_IV_SIZE, NULL, 0, &mac);
    if(ret!=SGX_SUCCESS) {
        return false;
    }

    auth_success = memcmp(auth_message, computed_auth, SGX_AESGCM_KEY_SIZE);

    if(auth_success == 0) {
        return true;
    } else {
        printf("authentication FAIL\n");
        return false;
    }
}