methods/gpgv.cc

   1 #include <apt-pkg/error.h>
   2 #include <apt-pkg/acquire-method.h>
   3 #include <apt-pkg/strutl.h>
   4 #include <apt-pkg/fileutl.h>
   5 #include <apti18n.h>
   6
   7 #include <utime.h>
   8 #include <stdio.h>
   9 #include <fcntl.h>
  10 #include <errno.h>
  11 #include <sys/wait.h>
  12 #include <iostream>
  13 #include <sstream>
  14
  15 #define GNUPGPREFIX "[GNUPG:]"
  16 #define GNUPGBADSIG "[GNUPG:] BADSIG"
  17 #define GNUPGNOPUBKEY "[GNUPG:] NO_PUBKEY"
  18 #define GNUPGVALIDSIG "[GNUPG:] VALIDSIG"
  19 #define GNUPGGOODSIG "[GNUPG:] GOODSIG"
  20 #define GNUPGKEYEXPIRED "[GNUPG:] KEYEXPIRED"
  21 #define GNUPGREVKEYSIG "[GNUPG:] REVKEYSIG"
  22 #define GNUPGNODATA "[GNUPG:] NODATA"
  23
  24 class GPGVMethod : public pkgAcqMethod
  25 {
  26    private:
  27    string VerifyGetSigners(const char *file, const char *outfile,
  28                                 vector<string> &GoodSigners,
  29                                 vector<string> &BadSigners,
  30                                 vector<string> &WorthlessSigners,
  31                                 vector<string> &NoPubKeySigners);
  32
  33    protected:
  34    virtual bool Fetch(FetchItem *Itm);
  35
  36    public:
  37
  38    GPGVMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig) {};
  39 };
  40
  41 string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile,
  42                                          vector<string> &GoodSigners,
  43                                          vector<string> &BadSigners,
  44                                          vector<string> &WorthlessSigners,
  45                                          vector<string> &NoPubKeySigners)
  46 {
  47    bool const Debug = _config->FindB("Debug::Acquire::gpgv", false);
  48    // setup a (empty) stringstream for formating the return value
  49    std::stringstream ret;
  50    ret.str("");
  51
  52    if (Debug == true)
  53       std::clog << "inside VerifyGetSigners" << std::endl;
  54
  55    pid_t pid;
  56    int fd[2];
  57    FILE *pipein;
  58    int status;
  59    string const gpgvpath = _config->Find("Dir::Bin::gpg", "/usr/bin/gpgv");
  60    // FIXME: remove support for deprecated APT::GPGV setting
  61    string const trustedFile = _config->FindFile("Dir::Etc::Trusted",
  62                         _config->Find("APT::GPGV::TrustedKeyring", "/etc/apt/trusted.gpg").c_str());
  63    string const trustedPath = _config->FindDir("Dir::Etc::TrustedParts", "/etc/apt/trusted.gpg.d");
  64    if (Debug == true)
  65    {
  66       std::clog << "gpgv path: " << gpgvpath << std::endl;
  67       std::clog << "Keyring file: " << trustedFile << std::endl;
  68       std::clog << "Keyring path: " << trustedPath << std::endl;
  69    }
  70
  71    vector<string> keyrings = GetListOfFilesInDir(trustedPath, "gpg", false);
  72    if (FileExists(trustedFile) == true)
  73       keyrings.push_back(trustedFile);
  74
  75    if (keyrings.empty() == true)
  76    {
  77       // TRANSLATOR: %s is the trusted keyring parts directory
  78       ioprintf(ret, _("No keyring installed in %s."), trustedPath.c_str());
  79       return ret.str();
  80    }
  81
  82    if (pipe(fd) < 0)
  83       return "Couldn't create pipe";
  84
  85    pid = fork();
  86    if (pid < 0)
  87       return string("Couldn't spawn new process") + strerror(errno);
  88    else if (pid == 0)
  89    {
  90       const char *Args[400];
  91       unsigned int i = 0;
  92
  93       Args[i++] = gpgvpath.c_str();
  94       Args[i++] = "--status-fd";
  95       Args[i++] = "3";
  96       Args[i++] = "--ignore-time-conflict";
  97       for (vector<string>::const_iterator K = keyrings.begin();
  98            K != keyrings.end(); ++K)
  99       {
 100          Args[i++] = "--keyring";
 101          Args[i++] = K->c_str();
 102          if(i >= 395) {
 103             std::clog << _("E: Too many keyrings should be passed to gpgv. Exiting.") << std::endl;
 104             exit(111);
 105          }
 106       }
 107
 108       Configuration::Item const *Opts;
 109       Opts = _config->Tree("Acquire::gpgv::Options");
 110       if (Opts != 0)
 111       {
 112          Opts = Opts->Child;
 113          for (; Opts != 0; Opts = Opts->Next)
 114          {
 115             if (Opts->Value.empty() == true)
 116                continue;
 117             Args[i++] = Opts->Value.c_str();
 118             if(i >= 395) {
 119                std::clog << _("E: Argument list from Acquire::gpgv::Options too long. Exiting.") << std::endl;
 120                exit(111);
 121             }
 122          }
 123       }
 124       Args[i++] = file;
 125       Args[i++] = outfile;
 126       Args[i++] = NULL;
 127
 128       if (Debug == true)
 129       {
 130          std::clog << "Preparing to exec: " << gpgvpath;
 131          for(unsigned int j=0;Args[j] != NULL; j++)
 132             std::clog << " " << Args[j];
 133          std::clog << std::endl;
 134       }
 135       int const nullfd = open("/dev/null", O_RDONLY);
 136       close(fd[0]);
 137       // Redirect output to /dev/null; we read from the status fd
 138       dup2(nullfd, STDOUT_FILENO);
 139       dup2(nullfd, STDERR_FILENO);
 140       // Redirect the pipe to the status fd (3)
 141       dup2(fd[1], 3);
 142
 143       putenv((char *)"LANG=");
 144       putenv((char *)"LC_ALL=");
 145       putenv((char *)"LC_MESSAGES=");
 146       execvp(gpgvpath.c_str(), (char **)Args);
 147
 148       exit(111);
 149    }
 150    close(fd[1]);
 151
 152    pipein = fdopen(fd[0], "r");
 153
 154    // Loop over the output of gpgv, and check the signatures.
 155    size_t buffersize = 64;
 156    char *buffer = (char *) malloc(buffersize);
 157    size_t bufferoff = 0;
 158    while (1)
 159    {
 160       int c;
 161
 162       // Read a line.  Sigh.
 163       while ((c = getc(pipein)) != EOF && c != '\n')
 164       {
 165          if (bufferoff == buffersize)
 166             buffer = (char *) realloc(buffer, buffersize *= 2);
 167          *(buffer+bufferoff) = c;
 168          bufferoff++;
 169       }
 170       if (bufferoff == 0 && c == EOF)
 171          break;
 172       *(buffer+bufferoff) = '\0';
 173       bufferoff = 0;
 174       if (Debug == true)
 175          std::clog << "Read: " << buffer << std::endl;
 176
 177       // Push the data into three separate vectors, which
 178       // we later concatenate.  They're kept separate so
 179       // if we improve the apt method communication stuff later
 180       // it will be better.
 181       if (strncmp(buffer, GNUPGBADSIG, sizeof(GNUPGBADSIG)-1) == 0)
 182       {
 183          if (Debug == true)
 184             std::clog << "Got BADSIG! " << std::endl;
 185          BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 186       }
 187
 188       if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0)
 189       {
 190          if (Debug == true)
 191             std::clog << "Got NO_PUBKEY " << std::endl;
 192          NoPubKeySigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 193       }
 194       if (strncmp(buffer, GNUPGNODATA, sizeof(GNUPGBADSIG)-1) == 0)
 195       {
 196          if (Debug == true)
 197             std::clog << "Got NODATA! " << std::endl;
 198          BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 199       }
 200       if (strncmp(buffer, GNUPGKEYEXPIRED, sizeof(GNUPGKEYEXPIRED)-1) == 0)
 201       {
 202          if (Debug == true)
 203             std::clog << "Got KEYEXPIRED! " << std::endl;
 204          WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 205       }
 206       if (strncmp(buffer, GNUPGREVKEYSIG, sizeof(GNUPGREVKEYSIG)-1) == 0)
 207       {
 208          if (Debug == true)
 209             std::clog << "Got REVKEYSIG! " << std::endl;
 210          WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 211       }
 212       if (strncmp(buffer, GNUPGGOODSIG, sizeof(GNUPGGOODSIG)-1) == 0)
 213       {
 214          char *sig = buffer + sizeof(GNUPGPREFIX);
 215          char *p = sig + sizeof("GOODSIG");
 216          while (*p && isxdigit(*p))
 217             p++;
 218          *p = 0;
 219          if (Debug == true)
 220             std::clog << "Got GOODSIG, key ID:" << sig << std::endl;
 221          GoodSigners.push_back(string(sig));
 222       }
 223    }
 224    fclose(pipein);
 225
 226    waitpid(pid, &status, 0);
 227    if (Debug == true)
 228    {
 229       std::clog << "gpgv exited\n";
 230    }
 231
 232    if (WEXITSTATUS(status) == 0)
 233    {
 234       if (GoodSigners.empty())
 235          return _("Internal error: Good signature, but could not determine key fingerprint?!");
 236       return "";
 237    }
 238    else if (WEXITSTATUS(status) == 1)
 239    {
 240       return _("At least one invalid signature was encountered.");
 241    }
 242    else if (WEXITSTATUS(status) == 111)
 243    {
 244       ioprintf(ret, _("Could not execute '%s' to verify signature (is gpgv installed?)"), gpgvpath.c_str());
 245       return ret.str();
 246    }
 247    else
 248    {
 249       return _("Unknown error executing gpgv");
 250    }
 251 }
 252
 253 bool GPGVMethod::Fetch(FetchItem *Itm)
 254 {
 255    URI Get = Itm->Uri;
 256    string Path = Get.Host + Get.Path; // To account for relative paths
 257    string keyID;
 258    vector<string> GoodSigners;
 259    vector<string> BadSigners;
 260    // a worthless signature is a expired or revoked one
 261    vector<string> WorthlessSigners;
 262    vector<string> NoPubKeySigners;
 263
 264    FetchResult Res;
 265    Res.Filename = Itm->DestFile;
 266    URIStart(Res);
 267
 268    // Run gpgv on file, extract contents and get the key ID of the signer
 269    string msg = VerifyGetSigners(Path.c_str(), Itm->DestFile.c_str(),
 270                                  GoodSigners, BadSigners, WorthlessSigners,
 271                                  NoPubKeySigners);
 272    if (GoodSigners.empty() || !BadSigners.empty() || !NoPubKeySigners.empty())
 273    {
 274       string errmsg;
 275       // In this case, something bad probably happened, so we just go
 276       // with what the other method gave us for an error message.
 277       if (BadSigners.empty() && WorthlessSigners.empty() && NoPubKeySigners.empty())
 278          errmsg = msg;
 279       else
 280       {
 281          if (!BadSigners.empty())
 282          {
 283             errmsg += _("The following signatures were invalid:\n");
 284             for (vector<string>::iterator I = BadSigners.begin();
 285                  I != BadSigners.end(); I++)
 286                errmsg += (*I + "\n");
 287          }
 288          if (!WorthlessSigners.empty())
 289          {
 290             errmsg += _("The following signatures were invalid:\n");
 291             for (vector<string>::iterator I = WorthlessSigners.begin();
 292                  I != WorthlessSigners.end(); I++)
 293                errmsg += (*I + "\n");
 294          }
 295          if (!NoPubKeySigners.empty())
 296          {
 297              errmsg += _("The following signatures couldn't be verified because the public key is not available:\n");
 298             for (vector<string>::iterator I = NoPubKeySigners.begin();
 299                  I != NoPubKeySigners.end(); I++)
 300                errmsg += (*I + "\n");
 301          }
 302       }
 303       // this is only fatal if we have no good sigs or if we have at
 304       // least one bad signature. good signatures and NoPubKey signatures
 305       // happen easily when a file is signed with multiple signatures
 306       if(GoodSigners.empty() or !BadSigners.empty())
 307          return _error->Error("%s", errmsg.c_str());
 308    }
 309
 310    // Just pass the raw output up, because passing it as a real data
 311    // structure is too difficult with the method stuff.  We keep it
 312    // as three separate vectors for future extensibility.
 313    Res.GPGVOutput = GoodSigners;
 314    Res.GPGVOutput.insert(Res.GPGVOutput.end(),BadSigners.begin(),BadSigners.end());
 315    Res.GPGVOutput.insert(Res.GPGVOutput.end(),NoPubKeySigners.begin(),NoPubKeySigners.end());
 316    URIDone(Res);
 317
 318    if (_config->FindB("Debug::Acquire::gpgv", false))
 319    {
 320       std::clog << "gpgv succeeded\n";
 321    }
 322
 323    return true;
 324 }
 325
 326
 327 int main()
 328 {
 329    setlocale(LC_ALL, "");
 330
 331    GPGVMethod Mth;
 332
 333    return Mth.Run();
 334 }