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