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