diff options
Diffstat (limited to 'methods/gpgv.cc')
-rw-r--r-- | methods/gpgv.cc | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/methods/gpgv.cc b/methods/gpgv.cc new file mode 100644 index 000000000..b34ea8d85 --- /dev/null +++ b/methods/gpgv.cc @@ -0,0 +1,261 @@ +#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(); +} |