app.cpp

#include "app.h"
#include <iostream>
#include <fstream>
#include <string.h>
#include <assert.h>
# include <unistd.h>
# include <pwd.h>
# define MAX_PATH FILENAME_MAX


#include "sgx_urts.h"
#include "sgx_uae_service.h"
#include "app.h"
#include "enclave_u.h"
using namespace std;

/* Global EID shared by multiple threads */
sgx_enclave_id_t global_eid = 0;

typedef struct _sgx_errlist_t {
    sgx_status_t err;
    const char *msg;
    const char *sug; /* Suggestion */
} sgx_errlist_t;

/* Error code returned by sgx_create_enclave */
static sgx_errlist_t sgx_errlist[] = {
    {
        SGX_ERROR_UNEXPECTED,
        "Unexpected error occurred.",
        NULL
    },
    {
        SGX_ERROR_INVALID_PARAMETER,
        "Invalid parameter.",
        NULL
    },
    {
        SGX_ERROR_OUT_OF_MEMORY,
        "Out of memory.",
        NULL
    },
    {
        SGX_ERROR_ENCLAVE_LOST,
        "Power transition occurred.",
        "Please refer to the sample \"PowerTransition\" for details."
    },
    {
        SGX_ERROR_INVALID_ENCLAVE,
        "Invalid enclave image.",
        NULL
    },
    {
        SGX_ERROR_INVALID_ENCLAVE_ID,
        "Invalid enclave identification.",
        NULL
    },
    {
        SGX_ERROR_INVALID_SIGNATURE,
        "Invalid enclave signature.",
        NULL
    },
    {
        SGX_ERROR_OUT_OF_EPC,
        "Out of EPC memory.",
        NULL
    },
    {
        SGX_ERROR_NO_DEVICE,
        "Invalid SGX device.",
        "Please make sure SGX module is enabled in the BIOS, and install SGX driver afterwards."
    },
    {
        SGX_ERROR_MEMORY_MAP_CONFLICT,
        "Memory map conflicted.",
        NULL
    },
    {
        SGX_ERROR_INVALID_METADATA,
        "Invalid enclave metadata.",
        NULL
    },
    {
        SGX_ERROR_DEVICE_BUSY,
        "SGX device was busy.",
        NULL
    },
    {
        SGX_ERROR_INVALID_VERSION,
        "Enclave version was invalid.",
        NULL
    },
    {
        SGX_ERROR_INVALID_ATTRIBUTE,
        "Enclave was not authorized.",
        NULL
    },
    {
        SGX_ERROR_ENCLAVE_FILE_ACCESS,
        "Can't open enclave file.",
        NULL
    },
    {
        SGX_ERROR_NDEBUG_ENCLAVE,
        "The enclave is signed as product enclave, and can not be created as debuggable enclave.",
        NULL
    },
};

/* Check error conditions for loading enclave */
void print_error_message(sgx_status_t ret)
{
    size_t idx = 0;
    size_t ttl = sizeof sgx_errlist/sizeof sgx_errlist[0];

    for (idx = 0; idx < ttl; idx++) {
        if(ret == sgx_errlist[idx].err) {
            if(NULL != sgx_errlist[idx].sug)
                printf("Info: %s\n", sgx_errlist[idx].sug);
            printf("Error: %s\n", sgx_errlist[idx].msg);
            break;
        }
    }

    if (idx == ttl)
        printf("Error: Unexpected error occurred.\n");
}

/* Initialize the enclave:
 *   Step 1: try to retrieve the launch token saved by last transaction
 *   Step 2: call sgx_create_enclave to initialize an enclave instance
 *   Step 3: save the launch token if it is updated
 */
int initialize_enclave(void)
{
    char token_path[MAX_PATH] = {'\0'};
    sgx_launch_token_t token = {0};
    sgx_status_t ret = SGX_ERROR_UNEXPECTED;
    int updated = 0;

    /* Step 1: try to retrieve the launch token saved by last transaction 
     *         if there is no token, then create a new one.
     */

    /* try to get the token saved in $HOME */
    const char *home_dir = getpwuid(getuid())->pw_dir;

    if (home_dir != NULL &&
        (strlen(home_dir)+strlen("/")+sizeof(TOKEN_FILENAME)+1) <= MAX_PATH) {
        /* compose the token path */
        strncpy(token_path, home_dir, strlen(home_dir));
        strncat(token_path, "/", strlen("/"));
        strncat(token_path, TOKEN_FILENAME, sizeof(TOKEN_FILENAME)+1);
    } else {
        /* if token path is too long or $HOME is NULL */
        strncpy(token_path, TOKEN_FILENAME, sizeof(TOKEN_FILENAME));
    }

    FILE *fp = fopen(token_path, "rb");
    if (fp == NULL && (fp = fopen(token_path, "wb")) == NULL) {
        printf("Warning: Failed to create/open the launch token file \"%s\".\n", token_path);
    }

    if (fp != NULL) {
        /* read the token from saved file */
        size_t read_num = fread(token, 1, sizeof(sgx_launch_token_t), fp);
        if (read_num != 0 && read_num != sizeof(sgx_launch_token_t)) {
            /* if token is invalid, clear the buffer */
            memset(&token, 0x0, sizeof(sgx_launch_token_t));
            printf("Warning: Invalid launch token read from \"%s\".\n", token_path);
        }
    }

    /* Step 2: call sgx_create_enclave to initialize an enclave instance */
    /* Debug Support: set 2nd parameter to 1 */
    ret = sgx_create_enclave(ENCLAVE_FILENAME, SGX_DEBUG_FLAG, &token, &updated, &global_eid, NULL);
    if (ret != SGX_SUCCESS) {
        print_error_message(ret);

        if (fp != NULL) fclose(fp);
        return -1;
    }

    /* Step 3: save the launch token if it is updated */

    if (updated == FALSE || fp == NULL) {
        /* if the token is not updated, or file handler is invalid, do not perform saving */
        if (fp != NULL) fclose(fp);
        return 0;
    }

    /* reopen the file with write capablity */
    fp = freopen(token_path, "wb", fp);
    if (fp == NULL) return 0;
    size_t write_num = fwrite(token, 1, sizeof(sgx_launch_token_t), fp);
    if (write_num != sizeof(sgx_launch_token_t))
        printf("Warning: Failed to save launch token to \"%s\".\n", token_path);
    fclose(fp);
    return 0;
}

/* OCall functions */
void ocall_print_string(const char *str)
{
    /* Proxy/Bridge will check the length and null-terminate 
     * the input string to prevent buffer overflow. 
     */
    printf("%s", str);
}


void ocall_print_uint(uint8_t * u, size_t size)
{
    printf("Info: uint8_t*: ");
    for(int i=0; i<size; i++)
    {   if(i%24==0)
            printf("\n");
        printf("%4d",(uint8_t) *(u+i));
    }
    printf("\n");
}

int encrypt_file(const char * path){

    fstream file(path, ios::in|ios::out|ios::binary);
    int file_size = 0;
    int crypt_len = 0;


    if(file.is_open())
    {
        
        file.seekg(0, file.end);
        file_size = static_cast<int> (file.tellg());
        uint8_t * plain = new uint8_t[file_size];
        file.seekg(0, ios::beg);    
        file.read(reinterpret_cast<char *>(plain), (streamsize)file_size);
        cout.write(reinterpret_cast<char*>(plain), file_size);
        uint8_t * crypt = (uint8_t*)malloc(sizeof(char)*file_size);
        crypt_len = file_size;
        ecall_encrypt(global_eid, plain, crypt, file_size);
        file.seekg(0, ios::beg);
        file.write(reinterpret_cast<const char*>(crypt), (streamsize)crypt_len);
        free(plain);
        free(crypt);
        file.close();
    }
    cout << "encrypted the file" << endl;    
}

int decrypt_file(const char * path)
{
    fstream file(path, ios::in|ios::out|ios::binary);
    int file_size = 0;
    int plain_len = 0;
    if(file.is_open())
    {
        
        file.seekg(0, file.end);
        file_size = static_cast<int> (file.tellg());
        uint8_t * crypt = new uint8_t[file_size];
        file.seekg(0, ios::beg);    
        file.read(reinterpret_cast<char *>(crypt), (streamsize)file_size);
        uint8_t * plain = (uint8_t*)malloc(sizeof(char)*file_size);
        plain_len = file_size;
        ecall_decrypt(global_eid, crypt, plain, file_size);
        file.seekg(0, ios::beg);
        cout.write(reinterpret_cast<char *>(plain), file_size);
        file.write(reinterpret_cast<const char*>(plain), (streamsize)plain_len);
        free(plain);
        free(crypt);
        file.close();
    }
    cout << "decrypted the file" << endl;
}


void ocall_save_ctx(const char * path, uint8_t *data, size_t size)
{
    fstream file(path, ios::in|ios::out|ios::binary);
    int file_size = 0;
   
    if(file.is_open())
    {
        file.seekg(0, ios::beg);    
        file.write(reinterpret_cast<char *>(data), (streamsize)size);        

        file.close();
    }

    cout << "seal secret from enclave --> disk file" << endl;
}

void ocall_get_secret(const char * path, uint8_t *data, size_t size)
{
    fstream file(path, ios::in|ios::out|ios::binary);
    int file_size = 0;
   
    if(file.is_open())
    {
        
        file.seekg(0, file.end);
        file_size = static_cast<int> (file.tellg());
        file.seekg(0, ios::beg);    
        file.read(reinterpret_cast<char *>(data), (streamsize)file_size);        

        file.close();
    }
    cout << "getting secret from disk file --> enclave" << endl;
}


int main(int argc, char * argv[])
{
    cout << "demo start..." << endl;
    cout << "load enclave" << endl;
    /* Initialize the enclave */
    if(initialize_enclave() < 0){
        printf("Enter a character before exit ...\n");
        getchar();
        return -1;
    }
    const char* filename = "test.txt";
    encrypt_file(filename);
    decrypt_file(filename);
    /* Destroy the enclave */
    sgx_destroy_enclave(global_eid);	
}