methods/gpgv.cc

   1 #include <config.h>
   2
   3 #include <apt-pkg/error.h>
   4 #include <apt-pkg/acquire-method.h>
   5 #include <apt-pkg/strutl.h>
   6 #include <apt-pkg/fileutl.h>
   7 #include <apt-pkg/indexcopy.h>
   8
   9 #include <utime.h>
  10 #include <stdio.h>
  11 #include <fcntl.h>
  12 #include <errno.h>
  13 #include <sys/wait.h>
  14 #include <iostream>
  15 #include <sstream>
  16 #include <vector>
  17
  18 #include <apti18n.h>
  19
  20 #define GNUPGPREFIX "[GNUPG:]"
  21 #define GNUPGBADSIG "[GNUPG:] BADSIG"
  22 #define GNUPGNOPUBKEY "[GNUPG:] NO_PUBKEY"
  23 #define GNUPGVALIDSIG "[GNUPG:] VALIDSIG"
  24 #define GNUPGGOODSIG "[GNUPG:] GOODSIG"
  25 #define GNUPGKEYEXPIRED "[GNUPG:] KEYEXPIRED"
  26 #define GNUPGREVKEYSIG "[GNUPG:] REVKEYSIG"
  27 #define GNUPGNODATA "[GNUPG:] NODATA"
  28
  29 class GPGVMethod : public pkgAcqMethod
  30 {
  31    private:
  32    string VerifyGetSigners(const char *file, const char *outfile,
  33                                 vector<string> &GoodSigners,
  34                                 vector<string> &BadSigners,
  35                                 vector<string> &WorthlessSigners,
  36                                 vector<string> &NoPubKeySigners);
  37
  38    protected:
  39    virtual bool Fetch(FetchItem *Itm);
  40
  41    public:
  42
  43    GPGVMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig) {};
  44 };
  45
  46 string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile,
  47                                          vector<string> &GoodSigners,
  48                                          vector<string> &BadSigners,
  49                                          vector<string> &WorthlessSigners,
  50                                          vector<string> &NoPubKeySigners)
  51 {
  52    bool const Debug = _config->FindB("Debug::Acquire::gpgv", false);
  53    // setup a (empty) stringstream for formating the return value
  54    std::stringstream ret;
  55    ret.str("");
  56
  57    if (Debug == true)
  58       std::clog << "inside VerifyGetSigners" << std::endl;
  59
  60    int fd[2];
  61
  62    if (pipe(fd) < 0)
  63       return "Couldn't create pipe";
  64
  65    pid_t pid = fork();
  66    if (pid < 0)
  67       return string("Couldn't spawn new process") + strerror(errno);
  68    else if (pid == 0)
  69    {
  70       _error->PushToStack();
  71       bool const success = SigVerify::RunGPGV(outfile, file, 3, fd);
  72       if (success == false)
  73       {
  74          string errmsg;
  75          _error->PopMessage(errmsg);
  76          _error->RevertToStack();
  77          return errmsg;
  78       }
  79       _error->RevertToStack();
  80       exit(111);
  81    }
  82    close(fd[1]);
  83
  84    FILE *pipein = fdopen(fd[0], "r");
  85
  86    // Loop over the output of gpgv, and check the signatures.
  87    size_t buffersize = 64;
  88    char *buffer = (char *) malloc(buffersize);
  89    size_t bufferoff = 0;
  90    while (1)
  91    {
  92       int c;
  93
  94       // Read a line.  Sigh.
  95       while ((c = getc(pipein)) != EOF && c != '\n')
  96       {
  97          if (bufferoff == buffersize)
  98             buffer = (char *) realloc(buffer, buffersize *= 2);
  99          *(buffer+bufferoff) = c;
 100          bufferoff++;
 101       }
 102       if (bufferoff == 0 && c == EOF)
 103          break;
 104       *(buffer+bufferoff) = '\0';
 105       bufferoff = 0;
 106       if (Debug == true)
 107          std::clog << "Read: " << buffer << std::endl;
 108
 109       // Push the data into three separate vectors, which
 110       // we later concatenate.  They're kept separate so
 111       // if we improve the apt method communication stuff later
 112       // it will be better.
 113       if (strncmp(buffer, GNUPGBADSIG, sizeof(GNUPGBADSIG)-1) == 0)
 114       {
 115          if (Debug == true)
 116             std::clog << "Got BADSIG! " << std::endl;
 117          BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 118       }
 119
 120       if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0)
 121       {
 122          if (Debug == true)
 123             std::clog << "Got NO_PUBKEY " << std::endl;
 124          NoPubKeySigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 125       }
 126       if (strncmp(buffer, GNUPGNODATA, sizeof(GNUPGBADSIG)-1) == 0)
 127       {
 128          if (Debug == true)
 129             std::clog << "Got NODATA! " << std::endl;
 130          BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 131       }
 132       if (strncmp(buffer, GNUPGKEYEXPIRED, sizeof(GNUPGKEYEXPIRED)-1) == 0)
 133       {
 134          if (Debug == true)
 135             std::clog << "Got KEYEXPIRED! " << std::endl;
 136          WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 137       }
 138       if (strncmp(buffer, GNUPGREVKEYSIG, sizeof(GNUPGREVKEYSIG)-1) == 0)
 139       {
 140          if (Debug == true)
 141             std::clog << "Got REVKEYSIG! " << std::endl;
 142          WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 143       }
 144       if (strncmp(buffer, GNUPGGOODSIG, sizeof(GNUPGGOODSIG)-1) == 0)
 145       {
 146          char *sig = buffer + sizeof(GNUPGPREFIX);
 147          char *p = sig + sizeof("GOODSIG");
 148          while (*p && isxdigit(*p))
 149             p++;
 150          *p = 0;
 151          if (Debug == true)
 152             std::clog << "Got GOODSIG, key ID:" << sig << std::endl;
 153          GoodSigners.push_back(string(sig));
 154       }
 155    }
 156    fclose(pipein);
 157
 158    int status;
 159    waitpid(pid, &status, 0);
 160    if (Debug == true)
 161    {
 162       std::clog << "gpgv exited\n";
 163    }
 164
 165    if (WEXITSTATUS(status) == 0)
 166    {
 167       if (GoodSigners.empty())
 168          return _("Internal error: Good signature, but could not determine key fingerprint?!");
 169       return "";
 170    }
 171    else if (WEXITSTATUS(status) == 1)
 172    {
 173       return _("At least one invalid signature was encountered.");
 174    }
 175    else if (WEXITSTATUS(status) == 111)
 176    {
 177       ioprintf(ret, _("Could not execute 'gpgv' to verify signature (is gpgv installed?)"));
 178       return ret.str();
 179    }
 180    else
 181    {
 182       return _("Unknown error executing gpgv");
 183    }
 184 }
 185
 186 bool GPGVMethod::Fetch(FetchItem *Itm)
 187 {
 188    URI Get = Itm->Uri;
 189    string Path = Get.Host + Get.Path; // To account for relative paths
 190    string keyID;
 191    vector<string> GoodSigners;
 192    vector<string> BadSigners;
 193    // a worthless signature is a expired or revoked one
 194    vector<string> WorthlessSigners;
 195    vector<string> NoPubKeySigners;
 196
 197    FetchResult Res;
 198    Res.Filename = Itm->DestFile;
 199    URIStart(Res);
 200
 201    // Run gpgv on file, extract contents and get the key ID of the signer
 202    string msg = VerifyGetSigners(Path.c_str(), Itm->DestFile.c_str(),
 203                                  GoodSigners, BadSigners, WorthlessSigners,
 204                                  NoPubKeySigners);
 205    if (GoodSigners.empty() || !BadSigners.empty() || !NoPubKeySigners.empty())
 206    {
 207       string errmsg;
 208       // In this case, something bad probably happened, so we just go
 209       // with what the other method gave us for an error message.
 210       if (BadSigners.empty() && WorthlessSigners.empty() && NoPubKeySigners.empty())
 211          errmsg = msg;
 212       else
 213       {
 214          if (!BadSigners.empty())
 215          {
 216             errmsg += _("The following signatures were invalid:\n");
 217             for (vector<string>::iterator I = BadSigners.begin();
 218                  I != BadSigners.end(); ++I)
 219                errmsg += (*I + "\n");
 220          }
 221          if (!WorthlessSigners.empty())
 222          {
 223             errmsg += _("The following signatures were invalid:\n");
 224             for (vector<string>::iterator I = WorthlessSigners.begin();
 225                  I != WorthlessSigners.end(); ++I)
 226                errmsg += (*I + "\n");
 227          }
 228          if (!NoPubKeySigners.empty())
 229          {
 230              errmsg += _("The following signatures couldn't be verified because the public key is not available:\n");
 231             for (vector<string>::iterator I = NoPubKeySigners.begin();
 232                  I != NoPubKeySigners.end(); ++I)
 233                errmsg += (*I + "\n");
 234          }
 235       }
 236       // this is only fatal if we have no good sigs or if we have at
 237       // least one bad signature. good signatures and NoPubKey signatures
 238       // happen easily when a file is signed with multiple signatures
 239       if(GoodSigners.empty() or !BadSigners.empty())
 240          return _error->Error("%s", errmsg.c_str());
 241    }
 242
 243    // Just pass the raw output up, because passing it as a real data
 244    // structure is too difficult with the method stuff.  We keep it
 245    // as three separate vectors for future extensibility.
 246    Res.GPGVOutput = GoodSigners;
 247    Res.GPGVOutput.insert(Res.GPGVOutput.end(),BadSigners.begin(),BadSigners.end());
 248    Res.GPGVOutput.insert(Res.GPGVOutput.end(),NoPubKeySigners.begin(),NoPubKeySigners.end());
 249    URIDone(Res);
 250
 251    if (_config->FindB("Debug::Acquire::gpgv", false))
 252    {
 253       std::clog << "gpgv succeeded\n";
 254    }
 255
 256    return true;
 257 }
 258
 259
 260 int main()
 261 {
 262    setlocale(LC_ALL, "");
 263
 264    GPGVMethod Mth;
 265
 266    return Mth.Run();
 267 }