#include <apt-pkg/error.h> #include <apt-pkg/acquire-method.h> #include <apt-pkg/strutl.h> #include <sys/stat.h> #include <unistd.h> #include <utime.h> #include <stdio.h> #include <fcntl.h> #include <errno.h> #include <sys/wait.h> #include <iostream> #define GNUPGPREFIX "[GNUPG:]" #define GNUPGBADSIG "[GNUPG:] BADSIG" #define GNUPGNOPUBKEY "[GNUPG:] NO_PUBKEY" #define GNUPGVALIDSIG "[GNUPG:] VALIDSIG" class GPGVMethod : public pkgAcqMethod { private: const char *VerifyGetSigners(const char *file, const char *outfile, vector<string> &GoodSigners, vector<string> &BadSigners, vector<string> &NoPubKeySigners); protected: virtual bool Fetch(FetchItem *Itm); public: GPGVMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig) {}; }; const char *GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, vector<string> &GoodSigners, vector<string> &BadSigners, vector<string> &NoPubKeySigners) { if (_config->FindB("Debug::Acquire::gpgv", false)) { std::cerr << "inside VerifyGetSigners" << std::endl; } pid_t pid; int fd[2]; FILE *pipein; int status; struct stat buff; string gpgvpath = _config->Find("Dir::Bin::gpg", "/usr/bin/gpgv"); string pubringpath = _config->Find("Apt::GPGV::TrustedKeyring", "/etc/apt/trusted.gpg"); if (_config->FindB("Debug::Acquire::gpgv", false)) { std::cerr << "gpgv path: " << gpgvpath << std::endl; std::cerr << "Keyring path: " << pubringpath << std::endl; } if (stat(pubringpath.c_str(), &buff) != 0) return (string("Couldn't access keyring: ") + strerror(errno)).c_str(); if (pipe(fd) < 0) { return "Couldn't create pipe"; } pid = fork(); if (pid < 0) { return (string("Couldn't spawn new process") + strerror(errno)).c_str(); } else if (pid == 0) { if (_config->FindB("Debug::Acquire::gpgv", false)) { std::cerr << "Preparing to exec: " << gpgvpath << " --status-fd 3 --keyring " << pubringpath << " " << file << " " << outfile << std::endl; } int nullfd = open("/dev/null", O_RDONLY); close(fd[0]); // Redirect output to /dev/null; we read from the status fd dup2(nullfd, STDOUT_FILENO); dup2(nullfd, STDERR_FILENO); // Redirect the pipe to the status fd (3) dup2(fd[1], 3); putenv("LANG="); putenv("LC_ALL="); putenv("LC_MESSAGES="); execlp(gpgvpath.c_str(), gpgvpath.c_str(), "--status-fd", "3", "--keyring", pubringpath.c_str(), file, outfile, NULL); exit(111); } close(fd[1]); pipein = fdopen(fd[0], "r"); // Loop over the output of gpgv, and check the signatures. size_t buffersize = 64; char *buffer = (char *) malloc(buffersize); size_t bufferoff = 0; while (1) { int c; // Read a line. Sigh. while ((c = getc(pipein)) != EOF && c != '\n') { if (bufferoff == buffersize) buffer = (char *) realloc(buffer, buffersize *= 2); *(buffer+bufferoff) = c; bufferoff++; } if (bufferoff == 0 && c == EOF) break; *(buffer+bufferoff) = '\0'; bufferoff = 0; if (_config->FindB("Debug::Acquire::gpgv", false)) std::cerr << "Read: " << buffer << std::endl; // Push the data into three separate vectors, which // we later concatenate. They're kept separate so // if we improve the apt method communication stuff later // it will be better. if (strncmp(buffer, GNUPGBADSIG, sizeof(GNUPGBADSIG)-1) == 0) { if (_config->FindB("Debug::Acquire::gpgv", false)) std::cerr << "Got BADSIG! " << std::endl; BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX))); } if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0) { if (_config->FindB("Debug::Acquire::gpgv", false)) std::cerr << "Got NO_PUBKEY " << std::endl; NoPubKeySigners.push_back(string(buffer+sizeof(GNUPGPREFIX))); } if (strncmp(buffer, GNUPGVALIDSIG, sizeof(GNUPGVALIDSIG)-1) == 0) { char *sig = buffer + sizeof(GNUPGPREFIX); char *p = sig + sizeof("VALIDSIG"); while (*p && isxdigit(*p)) p++; *p = 0; if (_config->FindB("Debug::Acquire::gpgv", false)) std::cerr << "Got VALIDSIG, key ID:" << sig << std::endl; GoodSigners.push_back(string(sig)); } } fclose(pipein); waitpid(pid, &status, 0); if (_config->FindB("Debug::Acquire::gpgv", false)) { std::cerr <<"gpgv exited\n"; } if (WEXITSTATUS(status) == 0) { if (GoodSigners.empty()) return "Internal error: Good signature, but could not determine key fingerprint?!"; return NULL; } else if (WEXITSTATUS(status) == 1) { return "At least one invalid signature was encountered."; } else if (WEXITSTATUS(status) == 111) { return (string("Could not execute ") + gpgvpath + string(" to verify signature (is gnupg installed?)")).c_str(); } else { return "Unknown error executing gpgv"; } } bool GPGVMethod::Fetch(FetchItem *Itm) { URI Get = Itm->Uri; string Path = Get.Host + Get.Path; // To account for relative paths string keyID; vector<string> GoodSigners; vector<string> BadSigners; vector<string> NoPubKeySigners; FetchResult Res; Res.Filename = Itm->DestFile; URIStart(Res); // Run gpgv on file, extract contents and get the key ID of the signer const char *msg = VerifyGetSigners(Path.c_str(), Itm->DestFile.c_str(), GoodSigners, BadSigners, NoPubKeySigners); if (GoodSigners.empty() || !BadSigners.empty() || !NoPubKeySigners.empty()) { string errmsg; // In this case, something bad probably happened, so we just go // with what the other method gave us for an error message. if (BadSigners.empty() && NoPubKeySigners.empty()) errmsg = msg; else { if (!BadSigners.empty()) { errmsg += "The following signatures were invalid:\n"; for (vector<string>::iterator I = BadSigners.begin(); I != BadSigners.end(); I++) errmsg += (*I + "\n"); } if (!NoPubKeySigners.empty()) { errmsg += "The following signatures couldn't be verified because the public key is not available:\n"; for (vector<string>::iterator I = NoPubKeySigners.begin(); I != NoPubKeySigners.end(); I++) errmsg += (*I + "\n"); } } return _error->Error(errmsg.c_str()); } // Transfer the modification times struct stat Buf; if (stat(Path.c_str(),&Buf) != 0) return _error->Errno("stat","Failed to stat %s", Path.c_str()); struct utimbuf TimeBuf; TimeBuf.actime = Buf.st_atime; TimeBuf.modtime = Buf.st_mtime; if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0) return _error->Errno("utime","Failed to set modification time"); if (stat(Itm->DestFile.c_str(),&Buf) != 0) return _error->Errno("stat","Failed to stat"); // Return a Done response Res.LastModified = Buf.st_mtime; Res.Size = Buf.st_size; // Just pass the raw output up, because passing it as a real data // structure is too difficult with the method stuff. We keep it // as three separate vectors for future extensibility. Res.GPGVOutput = GoodSigners; Res.GPGVOutput.insert(Res.GPGVOutput.end(),BadSigners.begin(),BadSigners.end()); Res.GPGVOutput.insert(Res.GPGVOutput.end(),NoPubKeySigners.begin(),NoPubKeySigners.end()); URIDone(Res); if (_config->FindB("Debug::Acquire::gpgv", false)) { std::cerr <<"gpgv suceeded\n"; } return true; } int main() { GPGVMethod Mth; return Mth.Run(); }