kaist-ina / sgx-tor

Tor anonymity network for SGX

SGX-Tor

Introduction

SGX-Tor is a Tor anonymity network in the SGX environment. This project will be published in NSDI'17.

Notice Due to the recent patch in remote attestation protocol in SGX SDK, we are currently updating and modifying the SGX-Tor code, which makes SGX-Tor does not correctly work. We believe we can release the new version of SGX-Tor in March.

Build and run

Linux environment

Install Intel SGX SDK for Linux:

• See (rootdir)/linux-driver/README.md and (rootdir)/linux-sdk/README.md

Build Libraries

$ cd (rootdir)/Enclave/TrustedLibrary/LibEvent_SGX
$ ./configure
$ make 
$ cd (rootdir)/Enclave/TrustedLibrary/OpenSSL_SGX
$ ./ina_setting.sh
$ make
$ cd (rootdir)/Enclave/TrustedLibrary/zlib-1.2.8
$ make

###Build SGX-Tor and Run in an enclave

$ cd (rootdir)/
$ make SGX_MODE=HW SGX_DEBUG=1
$ ./app

Windows environment

###Compile OpenSSL Libraries Install ActivePerl
Use 'VS2013 x64 Native Tools Command Prompt'

• Application and SGX OpenSSL library should be built respectively

$ cd (rootdir)/SGX-Tor_WIN/OpenSSL_APP
or
$ cd (rootdir)/SGX-Tor_WIN/OpenSSL_SGX

• compile

$ ina_setting.bat
$ ina_build.bat
bntest.obj : error LNK2019: messages are OK

• clean

$ ina_clean.bat

###Build LibEvent Libraries

• Application and SGX LibEvent library should be built respectively

$ cd (rootdir)/SGX-Tor_WIN/LibEvent_APP
or
$ cd (rootdir)/SGX-Tor_WIN/LibEvent_SGX

• compile

$ nmake -f Makefile.nmake

###Build ZLib Library

$ open folder (rootdir)/SGX-Tor_WIN/zlib-1.2.8/contrib/vstudio/vc11
$ start zlibvc.sln
$ change configuration to Release mdoe
$ change Platform to x64.
$ visual studio build

###Run SGX-Tor
SGX-Tor will be executed as a client. You can check it by using firefox browser

$ change configuration to Prerelease mdoe
$ change Platform to x64.
$ 'project TorSGX' mouse right click -> Properties
$ change Debugger to launch to Intel(R) SGX Debugger
$ change Working Directory to $(OutDir)
$ do same thing to 'project TorVS2012'
$ build each solution
$ run

• Warning: use sdk version 1.6 in this repository. SGX-Tor does not work on sdk version 1.7.

###For setting private network ####Setting torrc

these settings are needed only once

• setting three authorities
  

$open TorOriginial2012 directory 
$double click ina_fingerprint.bat
$double click ina_gencert.bat
$modify ip_list in ina_set_fingerprint.py to what you want
$(ex. "10.0.0.1", "10.0.0.2", "10.0.0.3")
$double click ina_set.bat 
$SGX-Tor_WIN/nodes/A00x/torrc ,/C001/torrc ... all torrc are changed to their own fingerprint.
$copy a DirAuthority line and paste another torrc
$ open torrc and change OrPort, Address and DirPort to appropriate value

• setting client

$ change DirAuthority lines in C001/torrc to authorities information 
$ set project arguments

• arguments setting
  


Contact

Seongmin Kim [email protected]
Juhyeng Han [email protected]
Jaehyeong Ha [email protected]

Authors

Seongmin Kim [email protected]
Juhyeng Han [email protected]
Jaehyeong Ha [email protected]
Taesoo Kim [email protected]
Dongsu Han [email protected]

Publications

Please use the citation below as the canonical reference to SGX-Tor.

Enhancing Security and Privacy of Tor's Ecosystem by using Trusted Execution Environments
Seongmin Kim, Juhyeng Han, Jaehyeong Ha, Taesoo Kim, Dongsu Han
NDSI 2017

@inproceedings{sgx-tor,
        title        = {{Enhancing Security and Privacy of Tor's Ecosystem by using Trusted Execution Environments}},
        author       = {Seongmin Kim and Juhyeng Han and Jaehyeong Ha Taesoo Kim and Dongsu Han},
        booktitle    = {14th USENIX Symposium on Networked Systems Design and Implementation (NSDI 17)},
        year         = 2017,
}

sgx-tor's Issues

client private key is leaked.

hi,sir
I think there is a securty issue here:
in file Enclave/TorSGX/rendservice.c:

• Create private key for client

if (client->client_key) {
      char *client_key_out = NULL;
      if (crypto_pk_write_private_key_to_string(client->client_key,
                                                &client_key_out, &len) != 0) {
        log_warn(LD_BUG, "Internal error: "
                 "crypto_pk_write_private_key_to_string() failed.");
        goto err;
      }
      if (rend_get_service_id(client->client_key, service_id)<0) {
        log_warn(LD_BUG, "Internal error: couldn't encode service ID.");
        /*
         * len is string length, not buffer length, but last byte is NUL
         * anyway.
         */
        memwipe(client_key_out, 0, len);
        tor_free(client_key_out);
        goto err;
      }
      written = tor_snprintf(buf + written, sizeof(buf) - written,
                             "client-key\n%s", client_key_out); // ===========>1. the private is written into buf
      memwipe(client_key_out, 0, len);
      tor_free(client_key_out);
      if (written < 0) {
        log_warn(LD_BUG, "Could not write client entry.");
        goto err;
      }
    }

    if (sgx_fputs(buf, cfile) < 0) { // ===========>2. buf is passed to  function sgx_fputs
      log_warn(LD_FS, "Could not append client entry to file: %s",
               strerror(errno));
      goto err;
    }

in file Enclave/TorSGX/TorSGX.cpp:

int sgx_fputs(const char *str, sgx_file *f)
{
	if(f == NULL || str == NULL) {
		printf("sgx_fputs: Error! sgx_fputs: wrong arguments (NULL)\n");
		return -1;
	}
	int retv = -1;
	long seek = f->seek;
	long content_len = f->content_len;
	long n = strlen(str);
	long mem_size = f->content_len > n + seek ? f->content_len : n + seek;	
	char *new_cont = (char *)sgx_calloc(1, mem_size); // // ===========>3. calloc memory , HOWEVER, the memory new_cont  points to is UNTRUSTED.  
	if (f->content != NULL) {
		int remain = content_len - seek - n;
		remain = remain > 0 ? remain : 0;
		memcpy(new_cont, f->content, seek); 
		memcpy(new_cont+seek, str, n);	//===========>4. client private key is copied to memory outside Enclave.
		memcpy(new_cont+seek+n, f->content, remain);
		f->content_len = seek+n+remain;	
		f->seek = seek+n;
		sgx_free(f->content);
		f->content = new_cont;
	}
	else {
		memcpy(new_cont, str, n);
		f->content_len = n;
		f->seek = n;
		f->content = new_cont;
	}	
	f->mtime = time(NULL);
	retv = n;
	return retv;
}

Compilation Issue Ubuntu

Hi all!
I am trying to compile your project on an Ubuntu 18.10.

I just cloned the repo and run:

cd (rootdir)/Enclave/TrustedLibrary/LibEvent_SGX
./configure
make

But I get this error:

bufferevent_openssl.c:237:2: note: (near initialization for 'methods_bufferevent')
bufferevent_openssl.c:228:19: error: storage size of 'methods_bufferevent' isn't known
 static BIO_METHOD methods_bufferevent = {

Could you help me, please?

'bufferevent_openssl.lo' failed

when i ran 'make' after ran './configure', i got this result.

Makefile:899: recipe for target 'bufferevent_openssl.lo' failed
make[2]: *** [bufferevent_openssl.lo] Error 1
make[2]: Leaving directory '/home/sgx/SGX-Tor/Enclave/TrustedLibrary/LibEvent_SGX'
Makefile:963: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/sgx/SGX-Tor/Enclave/TrustedLibrary/LibEvent_SGX'
Makefile:689: recipe for target 'all' failed
make: *** [all] Error 2

what should i do?

still build failed when I turned to sdk version 1.6,need help!!!

when I built libEvent_SGX:

When the connection fails, the request url is leaked.

When the connection fails, the request url is leaked. This does not satisfy the requirements of an anonymous network

SSL * s_connect(int sock, char * dest_url)
{
	SSL *ssl;
	int server = 0;
	if (g_ctx == NULL) {
		puts("SSL_CTX is NULL!");
		abort();
	}
	ssl = SSL_new(g_ctx);
	SSL_set_fd(ssl, sock);
	if (SSL_connect(ssl) != 1) {
		printf("Error: Could not build a SSL session to: %s.\n", dest_url); // ========>leak
	}
	else {
		//printf("Successfully enabled SSL/TLS session to: %s.\n", dest_url);
	}
	//printf("Finished SSL/TLS connection with server: %s.\n", dest_url);
	return ssl;
}

PrivateKey is leaked

in Enclave/TorSGX/control.c line 3883:

 tor_asprintf(&buf,
                   "250-ServiceID=%s\r\n"
                   "250-PrivateKey=%s:%s\r\n"
                   "250 OK\r\n",
                   service_id,
                   key_new_alg,
                   key_new_blob); // ====> PrivateKey is leaked

in file Enclave/TorSGX/compat.c line 624:

int
tor_asprintf(char **strp, const char *fmt, ...)
{
  int r;
  va_list args;
  va_start(args, fmt);
  r = tor_vasprintf(strp, fmt, args); //  ====> PrivateKey is flowed into args
  va_end(args);
  if (!*strp || r < 0) {
    log_err(LD_BUG, "Internal error in asprintf");
    tor_assert(0);
  }
  return r;
}

int
tor_vasprintf(char **strp, const char *fmt, va_list args)
{
  /* use a temporary variable in case *strp is in args. */
  char *strp_tmp=NULL;
#ifdef HAVE_VASPRINTF
  /* If the platform gives us one, use it. */
  int r = vasprintf(&strp_tmp, fmt, args);
  if (r < 0)
    *strp = NULL;
  else
    *strp = strp_tmp;
  return r;
#elif defined(HAVE__VSCPRINTF)
  /* On Windows, _vsnprintf won't tell us the length of the string if it
   * overflows, so we need to use _vcsprintf to tell how much to allocate */
  int len, r;
  len = _vscprintf(fmt, args);
  if (len < 0) {
    *strp = NULL;
    return -1;
  }
  strp_tmp = tor_malloc(len + 1);
  r = vsnprintf(strp_tmp, len+1, fmt, args);
  if (r != len) {
    tor_free(strp_tmp);
    *strp = NULL;
    return -1;
  }
  *strp = strp_tmp;
  return len;
#else
  /* Everywhere else, we have a decent vsnprintf that tells us how many
   * characters we need.  We give it a try on a short buffer first, since
   * it might be nice to avoid the second vsnprintf call.
   */
  char buf[128];
  int len, r;
  va_list tmp_args;
  va_copy(tmp_args, args); // =============> private key flowed into tmp_args
  len = vsnprintf(buf, sizeof(buf), fmt, tmp_args); 
  va_end(tmp_args);
  if (len < (int)sizeof(buf)) {
    *strp = tor_strdup(buf);
    return len;
  }
  strp_tmp = tor_malloc(len+1); // strp_tmp points to memory outside enclave
  r = vsnprintf(strp_tmp, len+1, fmt, args);// =============> private key flowed into strp_tmp ， so privateKey is writed out, this is a sensitive information leakage.
  if (r != len) {
    tor_free(strp_tmp);
    *strp = NULL;
    return -1;
  }
  *strp = strp_tmp;
  return len;
#endif
}

The code does not check the malloc result, and there is a risk of data leakage.

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 157 in 193d4f0

content = (char *)calloc(1, f->content_len);

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 158 in 193d4f0

memcpy(content, f->content, f->content_len);

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 138 in 193d4f0

torrc = (char *)calloc(1, strlen(app_torrc)+1);

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 139 in 193d4f0

memcpy(torrc, app_torrc, strlen(app_torrc)+1);

SGX-Tor/SGX-Tor_WIN/TorVS2012/TorSGX/TorSGX.cpp

Line 135 in 193d4f0

torrc = (char *)calloc(1, strlen(app_torrc)+1);

SGX-Tor/SGX-Tor_WIN/TorVS2012/TorSGX/TorSGX.cpp

Line 136 in 193d4f0

memcpy(torrc, app_torrc, strlen(app_torrc)+1);

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 472 in 193d4f0

(*out) = (char *)malloc(((*out_len) + 1) * sizeof(char));

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 473 in 193d4f0

memcpy(*out, ptr->data, (*out_len));

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 191 in 193d4f0

content = (char *)calloc(1, fcont_len);

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 192 in 193d4f0

memcpy(content, fcont, fcont_len);

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 89 in 193d4f0

torrc = (char *)calloc(1, strlen(app_torrc)+1);

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 90 in 193d4f0

memcpy(torrc, app_torrc, strlen(app_torrc)+1);

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 706 in 193d4f0

accept_ip = (unsigned long *)calloc(1, sizeof(unsigned long));

SGX-Tor/Enclave/TorSGX/TorSGX.cpp

Line 707 in 193d4f0

memcpy(accept_ip, &client_addr.sin_addr.s_addr, sizeof(unsigned long));