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 using std::string;
  21 using std::vector;
  22
  23 #define GNUPGPREFIX "[GNUPG:]"
  24 #define GNUPGBADSIG "[GNUPG:] BADSIG"
  25 #define GNUPGNOPUBKEY "[GNUPG:] NO_PUBKEY"
  26 #define GNUPGVALIDSIG "[GNUPG:] VALIDSIG"
  27 #define GNUPGGOODSIG "[GNUPG:] GOODSIG"
  28 #define GNUPGKEYEXPIRED "[GNUPG:] KEYEXPIRED"
  29 #define GNUPGREVKEYSIG "[GNUPG:] REVKEYSIG"
  30 #define GNUPGNODATA "[GNUPG:] NODATA"
  31
  32 class GPGVMethod : public pkgAcqMethod
  33 {
  34    private:
  35    string VerifyGetSigners(const char *file, const char *outfile,
  36                                 vector<string> &GoodSigners,
  37                                 vector<string> &BadSigners,
  38                                 vector<string> &WorthlessSigners,
  39                                 vector<string> &NoPubKeySigners);
  40
  41    protected:
  42    virtual bool Fetch(FetchItem *Itm);
  43
  44    public:
  45
  46    GPGVMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig) {};
  47 };
  48
  49 string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile,
  50                                          vector<string> &GoodSigners,
  51                                          vector<string> &BadSigners,
  52                                          vector<string> &WorthlessSigners,
  53                                          vector<string> &NoPubKeySigners)
  54 {
  55    bool const Debug = _config->FindB("Debug::Acquire::gpgv", false);
  56    // setup a (empty) stringstream for formating the return value
  57    std::stringstream ret;
  58    ret.str("");
  59
  60    if (Debug == true)
  61       std::clog << "inside VerifyGetSigners" << std::endl;
  62
  63    int fd[2];
  64
  65    if (pipe(fd) < 0)
  66       return "Couldn't create pipe";
  67
  68    pid_t pid = fork();
  69    if (pid < 0)
  70       return string("Couldn't spawn new process") + strerror(errno);
  71    else if (pid == 0)
  72    {
  73       _error->PushToStack();
  74       bool const success = SigVerify::RunGPGV(outfile, file, 3, fd);
  75       if (success == false)
  76       {
  77          string errmsg;
  78          _error->PopMessage(errmsg);
  79          _error->RevertToStack();
  80          return errmsg;
  81       }
  82       _error->RevertToStack();
  83       exit(111);
  84    }
  85    close(fd[1]);
  86
  87    FILE *pipein = fdopen(fd[0], "r");
  88
  89    // Loop over the output of gpgv, and check the signatures.
  90    size_t buffersize = 64;
  91    char *buffer = (char *) malloc(buffersize);
  92    size_t bufferoff = 0;
  93    while (1)
  94    {
  95       int c;
  96
  97       // Read a line.  Sigh.
  98       while ((c = getc(pipein)) != EOF && c != '\n')
  99       {
 100          if (bufferoff == buffersize)
 101             buffer = (char *) realloc(buffer, buffersize *= 2);
 102          *(buffer+bufferoff) = c;
 103          bufferoff++;
 104       }
 105       if (bufferoff == 0 && c == EOF)
 106          break;
 107       *(buffer+bufferoff) = '\0';
 108       bufferoff = 0;
 109       if (Debug == true)
 110          std::clog << "Read: " << buffer << std::endl;
 111
 112       // Push the data into three separate vectors, which
 113       // we later concatenate.  They're kept separate so
 114       // if we improve the apt method communication stuff later
 115       // it will be better.
 116       if (strncmp(buffer, GNUPGBADSIG, sizeof(GNUPGBADSIG)-1) == 0)
 117       {
 118          if (Debug == true)
 119             std::clog << "Got BADSIG! " << std::endl;
 120          BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 121       }
 122
 123       if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0)
 124       {
 125          if (Debug == true)
 126             std::clog << "Got NO_PUBKEY " << std::endl;
 127          NoPubKeySigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 128       }
 129       if (strncmp(buffer, GNUPGNODATA, sizeof(GNUPGBADSIG)-1) == 0)
 130       {
 131          if (Debug == true)
 132             std::clog << "Got NODATA! " << std::endl;
 133          BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 134       }
 135       if (strncmp(buffer, GNUPGKEYEXPIRED, sizeof(GNUPGKEYEXPIRED)-1) == 0)
 136       {
 137          if (Debug == true)
 138             std::clog << "Got KEYEXPIRED! " << std::endl;
 139          WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 140       }
 141       if (strncmp(buffer, GNUPGREVKEYSIG, sizeof(GNUPGREVKEYSIG)-1) == 0)
 142       {
 143          if (Debug == true)
 144             std::clog << "Got REVKEYSIG! " << std::endl;
 145          WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
 146       }
 147       if (strncmp(buffer, GNUPGGOODSIG, sizeof(GNUPGGOODSIG)-1) == 0)
 148       {
 149          char *sig = buffer + sizeof(GNUPGPREFIX);
 150          char *p = sig + sizeof("GOODSIG");
 151          while (*p && isxdigit(*p))
 152             p++;
 153          *p = 0;
 154          if (Debug == true)
 155             std::clog << "Got GOODSIG, key ID:" << sig << std::endl;
 156          GoodSigners.push_back(string(sig));
 157       }
 158    }
 159    fclose(pipein);
 160
 161    int status;
 162    waitpid(pid, &status, 0);
 163    if (Debug == true)
 164    {
 165       std::clog << "gpgv exited\n";
 166    }
 167
 168    if (WEXITSTATUS(status) == 0)
 169    {
 170       if (GoodSigners.empty())
 171          return _("Internal error: Good signature, but could not determine key fingerprint?!");
 172       return "";
 173    }
 174    else if (WEXITSTATUS(status) == 1)
 175    {
 176       return _("At least one invalid signature was encountered.");
 177    }
 178    else if (WEXITSTATUS(status) == 111)
 179    {
 180       ioprintf(ret, _("Could not execute 'gpgv' to verify signature (is gpgv installed?)"));
 181       return ret.str();
 182    }
 183    else
 184    {
 185       return _("Unknown error executing gpgv");
 186    }
 187 }
 188
 189 bool GPGVMethod::Fetch(FetchItem *Itm)
 190 {
 191    URI Get = Itm->Uri;
 192    string Path = Get.Host + Get.Path; // To account for relative paths
 193    string keyID;
 194    vector<string> GoodSigners;
 195    vector<string> BadSigners;
 196    // a worthless signature is a expired or revoked one
 197    vector<string> WorthlessSigners;
 198    vector<string> NoPubKeySigners;
 199
 200    FetchResult Res;
 201    Res.Filename = Itm->DestFile;
 202    URIStart(Res);
 203
 204    // Run gpgv on file, extract contents and get the key ID of the signer
 205    string msg = VerifyGetSigners(Path.c_str(), Itm->DestFile.c_str(),
 206                                  GoodSigners, BadSigners, WorthlessSigners,
 207                                  NoPubKeySigners);
 208    if (GoodSigners.empty() || !BadSigners.empty() || !NoPubKeySigners.empty())
 209    {
 210       string errmsg;
 211       // In this case, something bad probably happened, so we just go
 212       // with what the other method gave us for an error message.
 213       if (BadSigners.empty() && WorthlessSigners.empty() && NoPubKeySigners.empty())
 214          errmsg = msg;
 215       else
 216       {
 217          if (!BadSigners.empty())
 218          {
 219             errmsg += _("The following signatures were invalid:\n");
 220             for (vector<string>::iterator I = BadSigners.begin();
 221                  I != BadSigners.end(); ++I)
 222                errmsg += (*I + "\n");
 223          }
 224          if (!WorthlessSigners.empty())
 225          {
 226             errmsg += _("The following signatures were invalid:\n");
 227             for (vector<string>::iterator I = WorthlessSigners.begin();
 228                  I != WorthlessSigners.end(); ++I)
 229                errmsg += (*I + "\n");
 230          }
 231          if (!NoPubKeySigners.empty())
 232          {
 233              errmsg += _("The following signatures couldn't be verified because the public key is not available:\n");
 234             for (vector<string>::iterator I = NoPubKeySigners.begin();
 235                  I != NoPubKeySigners.end(); ++I)
 236                errmsg += (*I + "\n");
 237          }
 238       }
 239       // this is only fatal if we have no good sigs or if we have at
 240       // least one bad signature. good signatures and NoPubKey signatures
 241       // happen easily when a file is signed with multiple signatures
 242       if(GoodSigners.empty() or !BadSigners.empty())
 243          return _error->Error("%s", errmsg.c_str());
 244    }
 245
 246    // Just pass the raw output up, because passing it as a real data
 247    // structure is too difficult with the method stuff.  We keep it
 248    // as three separate vectors for future extensibility.
 249    Res.GPGVOutput = GoodSigners;
 250    Res.GPGVOutput.insert(Res.GPGVOutput.end(),BadSigners.begin(),BadSigners.end());
 251    Res.GPGVOutput.insert(Res.GPGVOutput.end(),NoPubKeySigners.begin(),NoPubKeySigners.end());
 252    URIDone(Res);
 253
 254    if (_config->FindB("Debug::Acquire::gpgv", false))
 255    {
 256       std::clog << "gpgv succeeded\n";
 257    }
 258
 259    return true;
 260 }
 261
 262
 263 int main()
 264 {
 265    setlocale(LC_ALL, "");
 266
 267    GPGVMethod Mth;
 268
 269    return Mth.Run();
 270 }