encfs/util/encfsctl.cpp

/*****************************************************************************
 * Author:   Valient Gough <vgough@pobox.com>
 *
 *****************************************************************************
 * Copyright (c) 2004, Valient Gough
 * 
 * This program is free software; you can distribute it and/or modify it under 
 * the terms of the GNU General Public License (GPL), as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */


#include "fs/encfs.h"

#include "base/autosprintf.h"
#include "base/config.h"
#include "base/Error.h"
#include "base/i18n.h"

#include "cipher/Cipher.h"
#include "cipher/BlockCipher.h"
#include "cipher/MAC.h"
#include "cipher/StreamCipher.h"

#include "fs/FileUtils.h"
#include "fs/Context.h"
#include "fs/FileNode.h"
#include "fs/DirNode.h"

#include <glog/logging.h>

#include <iostream>
#include <string>
#include <cstdio>
#include <list>

#include <getopt.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#ifdef HAVE_SSL
#define NO_DES
#include <openssl/ssl.h>
#endif

using namespace std;
using namespace gnu;
using namespace encfs;

static int showInfo( int argc, char **argv );
static int showVersion( int argc, char **argv );
static int showCiphers( int argc, char **argv );
static int chpasswd( int argc, char **argv );
static int chpasswdAutomaticly( int argc, char **argv );
static int cmd_ls( int argc, char **argv );
static int cmd_decode( int argc, char **argv );
static int cmd_encode( int argc, char **argv );
static int cmd_showcruft( int argc, char **argv );
static int cmd_cat( int argc, char **argv );
static int cmd_export( int argc, char **argv );
static int cmd_showKey( int argc, char **argv );

struct CommandOpts
{
  const char *name;
  int minOptions;
  int maxOptions;
  int (*func)(int argc, char **argv);
  const char *argStr;
  const char *usageStr;
} commands[] = 
{
  {"info", 1, 1, showInfo, "(root dir)", 
    // xgroup(usage)
    gettext_noop("  -- show information (Default command)")},
  {"showKey", 1, 1, cmd_showKey, "(root dir)", 
    // xgroup(usage)
    gettext_noop("  -- show key")},
  {"passwd", 1, 1, chpasswd, "(root dir)",
    // xgroup(usage)
    gettext_noop("  -- change password for volume")},
  {"autopasswd", 1, 1, chpasswdAutomaticly, "(root dir)",
    // xgroup(usage)
    gettext_noop("  -- change password for volume, taking password"
        " from standard input.\n\tNo prompts are issued.")},
  {"ls", 1, 2, cmd_ls, 0,0},
  {"showcruft", 1, 1, cmd_showcruft, "(root dir)",
    // xgroup(usage)
    gettext_noop("  -- show undecodable filenames in the volume")},
  {"cat", 2, 2, cmd_cat, "(root dir) path",
    // xgroup(usage)
    gettext_noop("  -- decodes the file and cats it to standard out")}, 
  {"decode", 1, 100, cmd_decode, "[--extpass=prog] (root dir) [encoded-name ...]",
    // xgroup(usage)
    gettext_noop("  -- decodes name and prints plaintext version")}, 
  {"encode", 1, 100, cmd_encode, "[--extpass=prog] (root dir) [plaintext-name ...]",
    // xgroup(usage)
    gettext_noop("  -- encodes a filename and print result")}, 
  {"export", 2, 2, cmd_export, "(root dir) path",
    // xgroup(usage)
    gettext_noop("  -- decrypts a volume and writes results to path")}, 
  {"--ciphers", 0, 0, showCiphers, "",
    // xgroup(usage)
    gettext_noop("  -- show available ciphers")},
  {"--version", 0, 0, showVersion, "", 
    // xgroup(usage)
    gettext_noop("  -- print version number and exit")},
  {0,0,0,0,0,0}
};


static
void usage(const char *name)
{
  cerr << autosprintf(_("encfsctl version %s"), VERSION) << "\n"
    << _("Usage:\n") 
    // displays usage commands, eg "./encfs (root dir) ..."
    // xgroup(usage)
    << autosprintf(_("%s (root dir)\n"
          "  -- displays information about the filesystem, or \n"), name);

  int offset = 0;
  while(commands[offset].name != 0)
  {
    if( commands[offset].argStr != 0 )
    {
      cerr << "encfsctl " << commands[offset].name << " " 
        << commands[offset].argStr << "\n"
        << gettext( commands[offset].usageStr ) << "\n";
    }
    ++offset;
  }

  cerr << "\n"
    // xgroup(usage)
    << autosprintf(_("Example: \n%s info ~/.crypt\n"), name)
    << "\n";
}

static bool checkDir( string &rootDir )
{
  if( !isDirectory( rootDir.c_str() ))
  {
    cout << autosprintf(_("directory %s does not exist.\n"),
        rootDir.c_str());
    return false;
  }
  if(rootDir[ rootDir.length()-1 ] != '/')
    rootDir.append("/");

  return true;
}

static int showVersion( int argc, char **argv )
{
  (void)argc;
  (void)argv;
  // xgroup(usage)
  cout << autosprintf(_("encfsctl version %s"), VERSION) << "\n";

  return EXIT_SUCCESS;
}

static int showCiphers( int argc, char **argv )
{
  (void)argc;
  (void)argv;
  list<string> names = BlockCipher::GetRegistry().GetAll();
  for (const string& name : names) {
    auto props = BlockCipher::GetRegistry().GetProperties(name.c_str());
    cout << _("Implementation: ") << name << "\n";
    cout << "\t" << _("Block cipher: ") << props->cipher << " / " << props->mode
        << " ( " << autosprintf(_("via %s"), props->library.c_str()) << " )\n";
    cout << "\t" << _("Key Sizes: ") << props->keySize << "\n";
  }
  
  names = StreamCipher::GetRegistry().GetAll();
  for (const string& name : names) {
    auto props = StreamCipher::GetRegistry().GetProperties(name.c_str());
    cout << _("Implementation: ") << name << "\n";
    cout << "\t" << _("Stream cipher: ") << props->cipher << " / " << props->mode
        << " ( " << autosprintf(_("via %s"), props->library.c_str()) << " )\n";
    cout << "\t" << _("Key Sizes: ") << props->keySize << "\n";
  }
  
  names = MessageAuthenticationCode::GetRegistry().GetAll();
  for (const string& name : names) {
    auto props = MessageAuthenticationCode::GetRegistry()
        .GetProperties(name.c_str());
    cout << _("Implementation: ") << name << "\n";
    cout << "\t" << _("HMAC: ") << props->hashFunction << " / " << props->mode
        << " ( " << autosprintf(_("via %s"), props->library.c_str()) << " )\n";
    cout << "\t" << _("Block size: ") << props->blockSize << "\n";
  }
  return EXIT_SUCCESS;
}

static int showInfo( int argc, char **argv )
{
  (void)argc;
  string rootDir = argv[1];
  if( !checkDir( rootDir ))
    return EXIT_FAILURE;

  EncfsConfig config;
  ConfigType type = readConfig( rootDir, config );

  // show information stored in config..
  switch(type)
  {
  case Config_None:
    // xgroup(diag)
    cout << _("Unable to load or parse config file\n");
    return EXIT_FAILURE;
  case Config_Prehistoric:
    // xgroup(diag)
    cout << _("A really old EncFS filesystem was found. \n"
        "It is not supported in this EncFS build.\n");
    return EXIT_FAILURE;
  case Config_V3:
    // xgroup(diag)
    cout << "\n" << autosprintf(_("Version 3 configuration; "
          "created by %s\n"), config.creator().c_str());
    break;
  case Config_V4:
    // xgroup(diag)
    cout << "\n" << autosprintf(_("Version 4 configuration; "
          "created by %s\n"), config.creator().c_str());
    break;
  case Config_V5:
  case Config_V6:
  case Config_V7:
    // xgroup(diag)
    cout << "\n" << autosprintf(_("Version %i configuration; "
          "created by %s (revision %i)\n"), 
        type,
        config.creator().c_str(),
        config.revision());
    break;
  }

  showFSInfo( config );

  return EXIT_SUCCESS;
}

static RootPtr initRootInfo(int &argc, char ** &argv)
{
  RootPtr result;
  shared_ptr<EncFS_Opts> opts( new EncFS_Opts() );
  opts->createIfNotFound = false;
  opts->checkKey = false;

  static struct option long_options[] = {
    {"extpass", 1, 0, 'p'},
    {0,0,0,0}
  };

  for(;;)
  {
    int option_index = 0;

    int res = getopt_long( argc, argv, "",
        long_options, &option_index);
    if(res == -1)
      break;

    switch(res)
    {
    case 'p':
      opts->passwordProgram.assign(optarg);
      break;
    default:
      LOG(WARNING) << "getopt error: " << res;
      break;
    }
  }

  argc -= optind;
  argv += optind;

  if(argc == 0)
  {
    cerr << _("Incorrect number of arguments") << "\n";
  } else
  {
    opts->rootDir = string( argv[0] );

    --argc;
    ++argv;

    if(checkDir( opts->rootDir ))
      result = initFS( NULL, opts );

    if(!result)
      cerr << _("Unable to initialize encrypted filesystem - check path.\n");
  }

  return result;
}

static RootPtr initRootInfo(const char* crootDir)
{
  string rootDir(crootDir);
  RootPtr result;

  if(checkDir( rootDir ))
  {
    shared_ptr<EncFS_Opts> opts( new EncFS_Opts() );
    opts->rootDir = rootDir;
    opts->createIfNotFound = false;
    opts->checkKey = false;
    result = initFS( NULL, opts );
  }

  if(!result)
    cerr << _("Unable to initialize encrypted filesystem - check path.\n");

  return result;
}

static int cmd_showKey( int argc, char **argv )
{
  RootPtr rootInfo = initRootInfo(argv[1]);

  if(!rootInfo)
    return EXIT_FAILURE;
  else
  {
    // encode with itself
    string b64Key = rootInfo->cipher->encodeAsString(
        rootInfo->volumeKey, rootInfo->volumeKey );

    cout << b64Key << "\n";

    return EXIT_SUCCESS;
  }
}

static int cmd_decode( int argc, char **argv )
{
  RootPtr rootInfo = initRootInfo(argc, argv);
  if(!rootInfo)
    return EXIT_FAILURE;

  if(argc > 0)
  {
    for(int i=0; i<argc; ++i)
    {
      string name = rootInfo->root->plainPath( argv[i] );
      cout << name << "\n";
    }
  } else
  {
    char buf[PATH_MAX+1];
    while(cin.getline(buf,PATH_MAX))
    {
      cout << rootInfo->root->plainPath( buf ) << "\n";
    }
  }
  return EXIT_SUCCESS;
}

static int cmd_encode( int argc, char **argv )
{
  RootPtr rootInfo = initRootInfo(argc, argv);
  if(!rootInfo)
    return EXIT_FAILURE;

  if(argc > 0)
  {
    for(int i=0; i<argc; ++i)
    {
      string name = rootInfo->root->cipherPathWithoutRoot(argv[i]);
      cout << name << "\n";
    }
  } else
  {
    char buf[PATH_MAX+1];
    while(cin.getline(buf,PATH_MAX))
    {
      cout << rootInfo->root->cipherPathWithoutRoot( buf ) << "\n";
    }
  }
  return EXIT_SUCCESS;
}

static int cmd_ls( int argc, char **argv )
{
  (void)argc;

  RootPtr rootInfo = initRootInfo(argv[1]);

  if(!rootInfo)
    return EXIT_FAILURE;

  // show files in directory
  {
    DirTraverse dt = rootInfo->root->openDir("/");
    if(dt.valid())
    {
      for(string name = dt.nextPlaintextName(); !name.empty(); 
          name = dt.nextPlaintextName())
      {
        shared_ptr<FileNode> fnode = 
          rootInfo->root->lookupNode( name.c_str(), "encfsctl-ls" );
        struct stat stbuf;
        fnode->getAttr( &stbuf );

        struct tm stm;
        localtime_r( &stbuf.st_mtime, &stm );
        stm.tm_year += 1900;
        // TODO: when I add "%s" to the end and name.c_str(), I get a
        // seg fault from within strlen.  Why ???
        printf("%11i %4i-%02i-%02i %02i:%02i:%02i %s\n",
            int(stbuf.st_size), 
            int(stm.tm_year), int(stm.tm_mon), int(stm.tm_mday),
            int(stm.tm_hour), int(stm.tm_min), int(stm.tm_sec),
            name.c_str());
      }
    }
  }

  return EXIT_SUCCESS;
}

// apply an operation to every block in the file
template<typename T>
int processContents( const shared_ptr<EncFS_Root> &rootInfo, 
    const char *path, T &op )
{
  int errCode = 0;
  shared_ptr<FileNode> node = rootInfo->root->openNode( path, "encfsctl",
      O_RDONLY, &errCode );

  if(!node)
  {
    // try treating filename as an enciphered path
    string plainName = rootInfo->root->plainPath( path );
    node = rootInfo->root->lookupNode( plainName.c_str(), "encfsctl" );
    if(node)
    {
      errCode = node->open( O_RDONLY );
      if(errCode < 0)
        node.reset();
    }
  }

  if(!node)
  {
    cerr << "unable to open " << path << "\n";
    return errCode;
  } else
  {
    unsigned char buf[512];
    int blocks = (node->getSize() + sizeof(buf)-1) / sizeof(buf);
    // read all the data in blocks
    for(int i=0; i<blocks; ++i)
    {
      int bytes = node->read(i*sizeof(buf), buf, sizeof(buf));
      int res = op(buf, bytes);
      if(res < 0)
        return res;
    }
  }
  return 0;
} 
	    
class WriteOutput
{
  int _fd;
public:
  WriteOutput(int fd) { _fd = fd; }
  ~WriteOutput() { close(_fd); }

  int operator()(const void *buf, int count)
  {
    return (int)write(_fd, buf, count);
  }
};

static int cmd_cat( int argc, char **argv )
{
  (void)argc;
  RootPtr rootInfo = initRootInfo(argv[1]);

  if(!rootInfo)
    return EXIT_FAILURE;

  const char *path = argv[2];
  WriteOutput output(STDOUT_FILENO);
  int errCode = processContents( rootInfo, path, output );

  return errCode;
}

static int copyLink(const struct stat &stBuf, 
    const shared_ptr<EncFS_Root> &rootInfo,
    const string &cpath, const string &destName )
{
  vector<char> buf(stBuf.st_size+1, 0);
  int res = ::readlink( cpath.c_str(), &buf[0], stBuf.st_size );
  if(res == -1)
  {
    cerr << "unable to readlink of " << cpath << "\n";
    return EXIT_FAILURE;
  }

  buf[res] = '\0';
  string decodedLink = rootInfo->root->plainPath(&buf[0]);

  res = ::symlink( decodedLink.c_str(), destName.c_str() );
  if(res == -1)
  {
    cerr << "unable to create symlink for " << cpath 
      << " to " << decodedLink << "\n";
  }

  return EXIT_SUCCESS;
}

static int copyContents(const shared_ptr<EncFS_Root> &rootInfo, 
                        const char* encfsName, const char* targetName)
{
  shared_ptr<FileNode> node = 
    rootInfo->root->lookupNode( encfsName, "encfsctl" );

  if(!node)
  {
    cerr << "unable to open " << encfsName << "\n";
    return EXIT_FAILURE;
  } else
  {
    struct stat st;

    if(node->getAttr(&st) != 0)
      return EXIT_FAILURE;

    if((st.st_mode & S_IFLNK) == S_IFLNK)
    {
      string d = rootInfo->root->cipherPath(encfsName);
      char linkContents[PATH_MAX+2];

      if(readlink (d.c_str(), linkContents, PATH_MAX + 1) <= 0)
      {
        cerr << "unable to read link " << encfsName << "\n";
        return EXIT_FAILURE;
      }
      symlink(rootInfo->root->plainPath(linkContents).c_str(), 
          targetName);
    } else
    {
      int outfd = creat(targetName, st.st_mode);

      WriteOutput output(outfd);
      processContents( rootInfo, encfsName, output );
    }
  }
  return EXIT_SUCCESS;
}

static bool endsWith(const string &str, char ch)
{
  if(str.empty())
    return false;
  else
    return str[str.length()-1] == ch;
}

static int traverseDirs(const shared_ptr<EncFS_Root> &rootInfo, 
    string volumeDir, string destDir)
{
  if(!endsWith(volumeDir, '/'))
    volumeDir.append("/");
  if(!endsWith(destDir, '/'))
    destDir.append("/");

  // Lookup directory node so we can create a destination directory
  // with the same permissions
  {
    struct stat st;
    shared_ptr<FileNode> dirNode = 
      rootInfo->root->lookupNode( volumeDir.c_str(), "encfsctl" );
    if(dirNode->getAttr(&st))
      return EXIT_FAILURE;

    mkdir(destDir.c_str(), st.st_mode);
  }

  // show files in directory
  DirTraverse dt = rootInfo->root->openDir(volumeDir.c_str());
  if(dt.valid())
  {
    for(string name = dt.nextPlaintextName(); !name.empty(); 
        name = dt.nextPlaintextName())
    {
      // Recurse to subdirectories
      if(name != "." && name != "..")
      {
        string plainPath = volumeDir + name;
        string cpath = rootInfo->root->cipherPath(plainPath.c_str());
        string destName = destDir + name;

        int r = EXIT_SUCCESS;
        struct stat stBuf;
        if( !lstat( cpath.c_str(), &stBuf ))
        {
          if( S_ISDIR( stBuf.st_mode ) )
          {
            traverseDirs(rootInfo, (plainPath + '/').c_str(), 
                destName + '/');
          } else if( S_ISLNK( stBuf.st_mode ))
          {
            r = copyLink( stBuf, rootInfo, cpath, destName );
          } else
          {
            r = copyContents(rootInfo, plainPath.c_str(), 
                destName.c_str());
          }
        } else
        {
          r = EXIT_FAILURE;
        }

        if(r != EXIT_SUCCESS)
          return r;
      }
    }
  }
  return EXIT_SUCCESS;
}

static int cmd_export( int argc, char **argv )
{
  (void)argc;

  RootPtr rootInfo = initRootInfo(argv[1]);

  if(!rootInfo)
    return EXIT_FAILURE;

  string destDir = argv[2];
  // if the dir doesn't exist, then create it (with user permission)
  if(!checkDir(destDir) && !userAllowMkdir(destDir.c_str(), 0700))
    return EXIT_FAILURE;

  return traverseDirs(rootInfo, "/", destDir);
}

int showcruft( const shared_ptr<EncFS_Root> &rootInfo, const char *dirName )
{
  int found = 0;
  DirTraverse dt = rootInfo->root->openDir( dirName );
  if(dt.valid())
  {
    bool showedDir = false;
    for(string name = dt.nextInvalid(); !name.empty(); 
        name = dt.nextInvalid())
    {
      string cpath = rootInfo->root->cipherPath( dirName );
      cpath += '/';
      cpath += name;

      if(!showedDir)
      {
        // just before showing a list of files in a directory
        cout << autosprintf(_("In directory %s: \n"), dirName);
        showedDir = true;
      }
      ++found;
      cout << cpath << "\n";
    }

    // now go back and look for directories to recurse into..
    dt = rootInfo->root->openDir( dirName );
    if(dt.valid())
    {
      for(string name = dt.nextPlaintextName(); !name.empty(); 
          name = dt.nextPlaintextName())
      {
        if( name == "." || name == "..")
          continue;

        string plainPath = dirName;
        plainPath += '/';
        plainPath += name;

        string cpath = rootInfo->root->cipherPath( plainPath.c_str() );

        if(isDirectory( cpath.c_str() ))
          found += showcruft( rootInfo, plainPath.c_str() );
      }
    }
  }

  return found;
}

/*
    iterate recursively through the filesystem and print out names of files
    which have filenames which cannot be decoded with the given key..
 */
static int cmd_showcruft( int argc, char **argv )
{
  (void)argc;

  RootPtr rootInfo = initRootInfo(argv[1]);

  if(!rootInfo)
    return EXIT_FAILURE;

  int filesFound = showcruft( rootInfo, "/" );

  cout << autosprintf("Found %i invalid file(s).", filesFound) << "\n";

  return EXIT_SUCCESS;
}

static int do_chpasswd( bool useStdin, bool annotate, int argc, char **argv )
{
  (void)argc;
  string rootDir = argv[1];
  if( !checkDir( rootDir ))
    return EXIT_FAILURE;

  EncfsConfig config;
  ConfigType cfgType = readConfig( rootDir, config );

  if(cfgType == Config_None)
  {
    cout << _("Unable to load or parse config file\n");
    return EXIT_FAILURE;
  }

  // instanciate proper cipher
  shared_ptr<Cipher> cipher = getCipher(config);
  if(!cipher)
  {
    cout << autosprintf(_("Unable to find specified cipher \"%s\"\n"),
        config.cipher().name().c_str());
    return EXIT_FAILURE;
  }

  // ask for existing password
  cout << _("Enter current Encfs password\n");
  if (annotate)
    cerr << "$PROMPT$ passwd" << endl;
  CipherKey userKey = getUserKey( config, useStdin );
  if(!userKey)
    return EXIT_FAILURE;

  // decode volume key using user key -- at this point we detect an incorrect
  // password if the key checksum does not match (causing readKey to fail).
  CipherKey volumeKey = cipher->readKey( 
      (const unsigned char *)config.key().ciphertext().data(), userKey );

  if(!volumeKey)
  {
    cout << _("Invalid password\n");
    return EXIT_FAILURE;
  }

  // Now, get New user key..
  userKey.reset();
  cout << _("Enter new Encfs password\n");

  // create new key
  if( useStdin )
  {
    if (annotate)
      cerr << "$PROMPT$ new_passwd" << endl;
  }

  userKey = getNewUserKey( config, useStdin, string(), string() );

  // re-encode the volume key using the new user key and write it out..
  int result = EXIT_FAILURE;
  if(userKey)
  {
    int encodedKeySize = cipher->encodedKeySize();
    unsigned char *keyBuf = new unsigned char[ encodedKeySize ];

    // encode volume key with new user key
    cipher->writeKey( volumeKey, keyBuf, userKey );
    userKey.reset();

    EncryptedKey *key = config.mutable_key();
    key->set_ciphertext( keyBuf, encodedKeySize );
    delete[] keyBuf;

    if(saveConfig( rootDir, config ))
    {
      // password modified -- changes volume key of filesystem..
      cout << _("Volume Key successfully updated.\n");
      result = EXIT_SUCCESS;
    } else
    {
      cout << _("Error saving modified config file.\n");
    }
  } else
  {
    cout << _("Error creating key\n");
  }

  volumeKey.reset();

  return result;
}

static int chpasswd( int argc, char **argv )
{
  return do_chpasswd( false, false, argc, argv );
}

static int chpasswdAutomaticly( int argc, char **argv )
{
  return do_chpasswd( true, false, argc, argv );
}


int main(int argc, char **argv)
{
  FLAGS_logtostderr = 1;
  FLAGS_minloglevel = 1;

  google::InitGoogleLogging(argv[0]);
  google::InstallFailureSignalHandler();

#ifdef LOCALEDIR
  setlocale( LC_ALL, "" );
  bindtextdomain( PACKAGE, LOCALEDIR );
  textdomain( PACKAGE );
#endif

#ifdef HAVE_SSL
  SSL_load_error_strings();
  SSL_library_init();
#endif

  if(argc < 2)
  {
    usage( argv[0] );
    return EXIT_FAILURE;
  }

  if(argc == 2 && !(*argv[1] == '-' && *(argv[1]+1) == '-'))
  {
    // default command when only 1 argument given -- treat the argument as
    // a directory..
    return showInfo( argc, argv );
  } else
  {
    // find the specified command
    int offset = 0;
    while(commands[offset].name != 0)
    {
      if(!strcmp( argv[1], commands[offset].name ))
        break;
      ++offset;
    }

    if(commands[offset].name == 0)
    {
      cerr << autosprintf(_("invalid command: \"%s\""), argv[1]) << "\n";
    } else
    {
      if((argc-2 < commands[offset].minOptions) || 
          (argc-2 > commands[offset].maxOptions))
      {
        cerr << autosprintf(
            _("Incorrect number of arguments for command \"%s\""), 
            argv[1]) << "\n";
      } else
        return (*commands[offset].func)( argc-1, argv+1 );
    }
  }

  return EXIT_FAILURE;
}