diff options
Diffstat (limited to 'apt-pkg/contrib/gpgv.cc')
| -rw-r--r-- | apt-pkg/contrib/gpgv.cc | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/apt-pkg/contrib/gpgv.cc b/apt-pkg/contrib/gpgv.cc new file mode 100644 index 000000000..c236a7289 --- /dev/null +++ b/apt-pkg/contrib/gpgv.cc @@ -0,0 +1,363 @@ +// -*- mode: cpp; mode: fold -*- +// Include Files /*{{{*/ +#include<config.h> + +#include <errno.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <fcntl.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/wait.h> + +#include<apt-pkg/configuration.h> +#include<apt-pkg/error.h> +#include<apt-pkg/strutl.h> +#include<apt-pkg/fileutl.h> +#include<apt-pkg/gpgv.h> + +#include <apti18n.h> + /*}}}*/ +char * GenerateTemporaryFileTemplate(const char *basename) /*{{{*/ +{ + const char *tmpdir = getenv("TMPDIR"); +#ifdef P_tmpdir + if (!tmpdir) + tmpdir = P_tmpdir; +#endif + if (!tmpdir) + tmpdir = "/tmp"; + + std::string out; + strprintf(out, "%s/%s.XXXXXX", tmpdir, basename); + return strdup(out.c_str()); +} + /*}}}*/ +// ExecGPGV - returns the command needed for verify /*{{{*/ +// --------------------------------------------------------------------- +/* Generating the commandline for calling gpgv is somehow complicated as + we need to add multiple keyrings and user supplied options. + Also, as gpgv has no options to enforce a certain reduced style of + clear-signed files (=the complete content of the file is signed and + the content isn't encoded) we do a divide and conquer approach here +*/ +void ExecGPGV(std::string const &File, std::string const &FileGPG, + int const &statusfd, int fd[2]) +{ + #define EINTERNAL 111 + std::string const gpgvpath = _config->Find("Dir::Bin::gpg", "/usr/bin/gpgv"); + // FIXME: remove support for deprecated APT::GPGV setting + std::string const trustedFile = _config->Find("APT::GPGV::TrustedKeyring", _config->FindFile("Dir::Etc::Trusted")); + std::string const trustedPath = _config->FindDir("Dir::Etc::TrustedParts"); + + bool const Debug = _config->FindB("Debug::Acquire::gpgv", false); + + if (Debug == true) + { + std::clog << "gpgv path: " << gpgvpath << std::endl; + std::clog << "Keyring file: " << trustedFile << std::endl; + std::clog << "Keyring path: " << trustedPath << std::endl; + } + + std::vector<std::string> keyrings; + if (DirectoryExists(trustedPath)) + keyrings = GetListOfFilesInDir(trustedPath, "gpg", false, true); + if (RealFileExists(trustedFile) == true) + keyrings.push_back(trustedFile); + + std::vector<const char *> Args; + Args.reserve(30); + + if (keyrings.empty() == true) + { + // TRANSLATOR: %s is the trusted keyring parts directory + ioprintf(std::cerr, _("No keyring installed in %s."), + _config->FindDir("Dir::Etc::TrustedParts").c_str()); + exit(EINTERNAL); + } + + Args.push_back(gpgvpath.c_str()); + Args.push_back("--ignore-time-conflict"); + + char statusfdstr[10]; + if (statusfd != -1) + { + Args.push_back("--status-fd"); + snprintf(statusfdstr, sizeof(statusfdstr), "%i", statusfd); + Args.push_back(statusfdstr); + } + + for (std::vector<std::string>::const_iterator K = keyrings.begin(); + K != keyrings.end(); ++K) + { + Args.push_back("--keyring"); + Args.push_back(K->c_str()); + } + + Configuration::Item const *Opts; + Opts = _config->Tree("Acquire::gpgv::Options"); + if (Opts != 0) + { + Opts = Opts->Child; + for (; Opts != 0; Opts = Opts->Next) + { + if (Opts->Value.empty() == true) + continue; + Args.push_back(Opts->Value.c_str()); + } + } + + int sigFd = -1; + int dataFd = -1; + std::vector<std::string> dataHeader; + char * sig = NULL; + char * data = NULL; + + // file with detached signature + if (FileGPG != File) + { + Args.push_back(FileGPG.c_str()); + Args.push_back(File.c_str()); + } + else // clear-signed file + { + sig = GenerateTemporaryFileTemplate("apt.sig"); + data = GenerateTemporaryFileTemplate("apt.data"); + if (sig == NULL || data == NULL) + { + ioprintf(std::cerr, "Couldn't create tempfiles for splitting up %s", File.c_str()); + exit(EINTERNAL); + } + + sigFd = mkstemp(sig); + dataFd = mkstemp(data); + int const duppedSigFd = dup(sigFd); + int const duppedDataFd = dup(dataFd); + + if (dataFd == -1 || sigFd == -1 || duppedDataFd == -1 || duppedSigFd == -1 || + SplitClearSignedFile(File, duppedDataFd, &dataHeader, duppedSigFd) == false) + { + if (dataFd != -1) + unlink(sig); + if (sigFd != -1) + unlink(data); + ioprintf(std::cerr, "Splitting up %s into data and signature failed", File.c_str()); + exit(EINTERNAL); + } + lseek(dataFd, 0, SEEK_SET); + lseek(sigFd, 0, SEEK_SET); + Args.push_back(sig); + Args.push_back(data); + } + + Args.push_back(NULL); + + if (Debug == true) + { + std::clog << "Preparing to exec: " << gpgvpath; + for (std::vector<const char *>::const_iterator a = Args.begin(); *a != NULL; ++a) + std::clog << " " << *a; + std::clog << std::endl; + } + + if (statusfd != -1) + { + int const nullfd = open("/dev/null", O_RDONLY); + close(fd[0]); + // Redirect output to /dev/null; we read from the status fd + if (statusfd != STDOUT_FILENO) + dup2(nullfd, STDOUT_FILENO); + if (statusfd != STDERR_FILENO) + dup2(nullfd, STDERR_FILENO); + // Redirect the pipe to the status fd (3) + dup2(fd[1], statusfd); + + putenv((char *)"LANG="); + putenv((char *)"LC_ALL="); + putenv((char *)"LC_MESSAGES="); + } + + if (FileGPG != File) + { + execvp(gpgvpath.c_str(), (char **) &Args[0]); + ioprintf(std::cerr, "Couldn't execute %s to check %s", Args[0], File.c_str()); + exit(EINTERNAL); + } + else + { +//#define UNLINK_EXIT(X) exit(X) +#define UNLINK_EXIT(X) unlink(sig);unlink(data);exit(X) + + // for clear-signed files we have created tempfiles we have to clean up + // and we do an additional check, so fork yet another time … + pid_t pid = ExecFork(); + if(pid < 0) { + ioprintf(std::cerr, "Fork failed for %s to check %s", Args[0], File.c_str()); + UNLINK_EXIT(EINTERNAL); + } + if(pid == 0) + { + if (statusfd != -1) + dup2(fd[1], statusfd); + execvp(gpgvpath.c_str(), (char **) &Args[0]); + ioprintf(std::cerr, "Couldn't execute %s to check %s", Args[0], File.c_str()); + UNLINK_EXIT(EINTERNAL); + } + + // Wait and collect the error code - taken from WaitPid as we need the exact Status + int Status; + while (waitpid(pid,&Status,0) != pid) + { + if (errno == EINTR) + continue; + ioprintf(std::cerr, _("Waited for %s but it wasn't there"), "gpgv"); + UNLINK_EXIT(EINTERNAL); + } + + // check if it exit'ed normally … + if (WIFEXITED(Status) == false) + { + ioprintf(std::cerr, _("Sub-process %s exited unexpectedly"), "gpgv"); + UNLINK_EXIT(EINTERNAL); + } + + // … and with a good exit code + if (WEXITSTATUS(Status) != 0) + { + ioprintf(std::cerr, _("Sub-process %s returned an error code (%u)"), "gpgv", WEXITSTATUS(Status)); + UNLINK_EXIT(WEXITSTATUS(Status)); + } + + /* looks like its fine. Our caller will check the status fd, + but we construct a good-known clear-signed file without garbage + and other non-sense. In a perfect world, we get the same file, + but empty lines, trailing whitespaces and stuff makes it inperfect … */ + if (RecombineToClearSignedFile(File, dataFd, dataHeader, sigFd) == false) + { + _error->DumpErrors(std::cerr); + UNLINK_EXIT(EINTERNAL); + } + + // everything fine, we have a clean file now! + UNLINK_EXIT(0); +#undef UNLINK_EXIT + } + exit(EINTERNAL); // unreachable safe-guard +} + /*}}}*/ +// RecombineToClearSignedFile - combine data/signature to message /*{{{*/ +bool RecombineToClearSignedFile(std::string const &OutFile, int const ContentFile, + std::vector<std::string> const &ContentHeader, int const SignatureFile) +{ + FILE *clean_file = fopen(OutFile.c_str(), "w"); + fputs("-----BEGIN PGP SIGNED MESSAGE-----\n", clean_file); + for (std::vector<std::string>::const_iterator h = ContentHeader.begin(); h != ContentHeader.end(); ++h) + fprintf(clean_file, "%s\n", h->c_str()); + fputs("\n", clean_file); + + FILE *data_file = fdopen(ContentFile, "r"); + FILE *sig_file = fdopen(SignatureFile, "r"); + if (data_file == NULL || sig_file == NULL) + return _error->Error("Couldn't open splitfiles to recombine them into %s", OutFile.c_str()); + char *buf = NULL; + size_t buf_size = 0; + while (getline(&buf, &buf_size, data_file) != -1) + fputs(buf, clean_file); + fclose(data_file); + fputs("\n", clean_file); + while (getline(&buf, &buf_size, sig_file) != -1) + fputs(buf, clean_file); + fclose(sig_file); + fclose(clean_file); + return true; +} + /*}}}*/ +// SplitClearSignedFile - split message into data/signature /*{{{*/ +bool SplitClearSignedFile(std::string const &InFile, int const ContentFile, + std::vector<std::string> * const ContentHeader, int const SignatureFile) +{ + FILE *in = fopen(InFile.c_str(), "r"); + if (in == NULL) + return _error->Errno("fopen", "can not open %s", InFile.c_str()); + + FILE *out_content = NULL; + FILE *out_signature = NULL; + if (ContentFile != -1) + { + out_content = fdopen(ContentFile, "w"); + if (out_content == NULL) + return _error->Errno("fdopen", "Failed to open file to write content to from %s", InFile.c_str()); + } + if (SignatureFile != -1) + { + out_signature = fdopen(SignatureFile, "w"); + if (out_signature == NULL) + return _error->Errno("fdopen", "Failed to open file to write signature to from %s", InFile.c_str()); + } + + bool found_message_start = false; + bool found_message_end = false; + bool skip_until_empty_line = false; + bool found_signature = false; + bool first_line = true; + + char *buf = NULL; + size_t buf_size = 0; + while (getline(&buf, &buf_size, in) != -1) + { + _strrstrip(buf); + if (found_message_start == false) + { + if (strcmp(buf, "-----BEGIN PGP SIGNED MESSAGE-----") == 0) + { + found_message_start = true; + skip_until_empty_line = true; + } + } + else if (skip_until_empty_line == true) + { + if (strlen(buf) == 0) + skip_until_empty_line = false; + // save "Hash" Armor Headers, others aren't allowed + else if (ContentHeader != NULL && strncmp(buf, "Hash: ", strlen("Hash: ")) == 0) + ContentHeader->push_back(buf); + } + else if (found_signature == false) + { + if (strcmp(buf, "-----BEGIN PGP SIGNATURE-----") == 0) + { + found_signature = true; + found_message_end = true; + if (out_signature != NULL) + fprintf(out_signature, "%s\n", buf); + } + else if (found_message_end == false) + { + // we are in the message block + if(first_line == true) // first line does not need a newline + { + if (out_content != NULL) + fprintf(out_content, "%s", buf); + first_line = false; + } + else if (out_content != NULL) + fprintf(out_content, "\n%s", buf); + } + } + else if (found_signature == true) + { + if (out_signature != NULL) + fprintf(out_signature, "%s\n", buf); + if (strcmp(buf, "-----END PGP SIGNATURE-----") == 0) + found_signature = false; // look for other signatures + } + // all the rest is whitespace, unsigned garbage or additional message blocks we ignore + } + if (out_content != NULL) + fclose(out_content); + if (out_signature != NULL) + fclose(out_signature); + + return true; +} |