diff options
Diffstat (limited to 'apt-pkg/contrib/gpgv.cc')
| -rw-r--r-- | apt-pkg/contrib/gpgv.cc | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/apt-pkg/contrib/gpgv.cc b/apt-pkg/contrib/gpgv.cc new file mode 100644 index 000000000..cdf9481cb --- /dev/null +++ b/apt-pkg/contrib/gpgv.cc @@ -0,0 +1,464 @@ +// -*- mode: cpp; mode: fold -*- +// Include Files /*{{{*/ +#include<config.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 <errno.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <fcntl.h> +#include <sys/wait.h> +#include <unistd.h> +#include <stddef.h> + +#include <algorithm> +#include <fstream> +#include <iostream> +#include <sstream> +#include <string> +#include <vector> + +#include <apti18n.h> + /*}}}*/ +static char * GenerateTemporaryFileTemplate(const char *basename) /*{{{*/ +{ + std::string out; + std::string tmpdir = GetTempDir(); + strprintf(out, "%s/%s.XXXXXX", tmpdir.c_str(), basename); + return strdup(out.c_str()); +} + /*}}}*/ +// ExecGPGV - returns the command needed for verify /*{{{*/ +// --------------------------------------------------------------------- +/* Generating the commandline for calling gpg is somehow complicated as + we need to add multiple keyrings and user supplied options. + Also, as gpg 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 + and split up the clear-signed file in message and signature for gpg. + And as a cherry on the cake, we use our apt-key wrapper to do part + of the lifting in regards to merging keyrings. Fun for the whole family. +*/ +static bool iovprintf(std::ostream &out, const char *format, + va_list &args, ssize_t &size) { + char *S = (char*)malloc(size); + ssize_t const n = vsnprintf(S, size, format, args); + if (n > -1 && n < size) { + out << S; + free(S); + return true; + } else { + if (n > -1) + size = n + 1; + else + size *= 2; + } + free(S); + return false; +} +static void APT_PRINTF(4) apt_error(std::ostream &outterm, int const statusfd, int fd[2], const char *format, ...) +{ + std::ostringstream outstr; + std::ostream &out = (statusfd == -1) ? outterm : outstr; + va_list args; + ssize_t size = 400; + while (true) { + bool ret; + va_start(args,format); + ret = iovprintf(out, format, args, size); + va_end(args); + if (ret == true) + break; + } + if (statusfd != -1) + { + auto const errtag = "[APTKEY:] ERROR "; + outstr << '\n'; + auto const errtext = outstr.str(); + if (FileFd::Write(fd[1], errtag, strlen(errtag)) == false || + FileFd::Write(fd[1], errtext.data(), errtext.size()) == false) + outterm << errtext << std::flush; + } +} +void ExecGPGV(std::string const &File, std::string const &FileGPG, + int const &statusfd, int fd[2], std::string const &key) +{ + #define EINTERNAL 111 + std::string const aptkey = _config->Find("Dir::Bin::apt-key", CMAKE_INSTALL_FULL_BINDIR "/apt-key"); + + bool const Debug = _config->FindB("Debug::Acquire::gpgv", false); + struct exiter { + std::vector<const char *> files; + void operator ()(int code) APT_NORETURN { + std::for_each(files.begin(), files.end(), unlink); + exit(code); + } + } local_exit; + + + std::vector<const char *> Args; + Args.reserve(10); + + Args.push_back(aptkey.c_str()); + Args.push_back("--quiet"); + Args.push_back("--readonly"); + if (key.empty() == false) + { + if (key[0] == '/') + { + Args.push_back("--keyring"); + Args.push_back(key.c_str()); + } + else + { + Args.push_back("--keyid"); + Args.push_back(key.c_str()); + } + } + Args.push_back("verify"); + + char statusfdstr[10]; + if (statusfd != -1) + { + Args.push_back("--status-fd"); + snprintf(statusfdstr, sizeof(statusfdstr), "%i", statusfd); + Args.push_back(statusfdstr); + } + + 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()); + } + } + + enum { DETACHED, CLEARSIGNED } releaseSignature = (FileGPG != File) ? DETACHED : CLEARSIGNED; + char * sig = NULL; + char * data = NULL; + char * conf = nullptr; + + // Dump the configuration so apt-key picks up the correct Dir values + { + conf = GenerateTemporaryFileTemplate("apt.conf"); + if (conf == nullptr) { + apt_error(std::cerr, statusfd, fd, "Couldn't create tempfile names for passing config to apt-key"); + local_exit(EINTERNAL); + } + int confFd = mkstemp(conf); + if (confFd == -1) { + apt_error(std::cerr, statusfd, fd, "Couldn't create temporary file %s for passing config to apt-key", conf); + local_exit(EINTERNAL); + } + local_exit.files.push_back(conf); + + std::ofstream confStream(conf); + close(confFd); + _config->Dump(confStream); + confStream.close(); + setenv("APT_CONFIG", conf, 1); + } + + if (releaseSignature == DETACHED) + { + 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) + { + apt_error(std::cerr, statusfd, fd, "Couldn't create tempfile names for splitting up %s", File.c_str()); + local_exit(EINTERNAL); + } + + int const sigFd = mkstemp(sig); + int const dataFd = mkstemp(data); + if (dataFd != -1) + local_exit.files.push_back(data); + if (sigFd != -1) + local_exit.files.push_back(sig); + if (sigFd == -1 || dataFd == -1) + { + apt_error(std::cerr, statusfd, fd, "Couldn't create tempfiles for splitting up %s", File.c_str()); + local_exit(EINTERNAL); + } + + FileFd signature; + signature.OpenDescriptor(sigFd, FileFd::WriteOnly, true); + FileFd message; + message.OpenDescriptor(dataFd, FileFd::WriteOnly, true); + + if (signature.Failed() == true || message.Failed() == true || + SplitClearSignedFile(File, &message, nullptr, &signature) == false) + { + apt_error(std::cerr, statusfd, fd, "Splitting up %s into data and signature failed", File.c_str()); + local_exit(112); + } + Args.push_back(sig); + Args.push_back(data); + } + + Args.push_back(NULL); + + if (Debug == true) + { + std::clog << "Preparing to exec: "; + 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_WRONLY); + 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="); + } + + + // 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) { + apt_error(std::cerr, statusfd, fd, "Fork failed for %s to check %s", Args[0], File.c_str()); + local_exit(EINTERNAL); + } + if(pid == 0) + { + if (statusfd != -1) + dup2(fd[1], statusfd); + execvp(Args[0], (char **) &Args[0]); + apt_error(std::cerr, statusfd, fd, "Couldn't execute %s to check %s", Args[0], File.c_str()); + local_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; + apt_error(std::cerr, statusfd, fd, _("Waited for %s but it wasn't there"), "apt-key"); + local_exit(EINTERNAL); + } + + // check if it exit'ed normally … + if (WIFEXITED(Status) == false) + { + apt_error(std::cerr, statusfd, fd, _("Sub-process %s exited unexpectedly"), "apt-key"); + local_exit(EINTERNAL); + } + + // … and with a good exit code + if (WEXITSTATUS(Status) != 0) + { + // we forward the statuscode, so don't generate a message on the fd in this case + apt_error(std::cerr, -1, fd, _("Sub-process %s returned an error code (%u)"), "apt-key", WEXITSTATUS(Status)); + local_exit(WEXITSTATUS(Status)); + } + + // everything fine + local_exit(0); +} + /*}}}*/ +// SplitClearSignedFile - split message into data/signature /*{{{*/ +static int GetLineErrno(char **lineptr, size_t *n, FILE *stream, std::string const &InFile) +{ + int result; + + errno = 0; + result = getline(lineptr, n, stream); + if (errno != 0) + { + _error->Errno("getline", "Could not read from %s", InFile.c_str()); + return -1; + } + + return result; +} +bool SplitClearSignedFile(std::string const &InFile, FileFd * const ContentFile, + std::vector<std::string> * const ContentHeader, FileFd * const SignatureFile) +{ + FILE *in = fopen(InFile.c_str(), "r"); + if (in == NULL) + return _error->Errno("fopen", "can not open %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; + bool signed_message_not_on_first_line = false; + bool found_garbage = false; + + char *buf = NULL; + size_t buf_size = 0; + _error->PushToStack(); + while (GetLineErrno(&buf, &buf_size, in, InFile) != -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 + signed_message_not_on_first_line = found_garbage = 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 (SignatureFile != NULL) + { + SignatureFile->Write(buf, strlen(buf)); + SignatureFile->Write("\n", 1); + } + } + else if (found_message_end == false) // we are in the message block + { + // we don't have any fields which need dash-escaped, + // but implementations are free to encode all lines … + char const * dashfree = buf; + if (strncmp(dashfree, "- ", 2) == 0) + dashfree += 2; + if(first_line == true) // first line does not need a newline + first_line = false; + else if (ContentFile != NULL) + ContentFile->Write("\n", 1); + else + continue; + if (ContentFile != NULL) + ContentFile->Write(dashfree, strlen(dashfree)); + } + else + found_garbage = true; + } + else if (found_signature == true) + { + if (SignatureFile != NULL) + { + SignatureFile->Write(buf, strlen(buf)); + SignatureFile->Write("\n", 1); + } + 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 + else + found_garbage = true; + } + fclose(in); + if (buf != NULL) + free(buf); + + // Flush the files. Errors will be checked below. + if (SignatureFile != nullptr) + SignatureFile->Flush(); + if (ContentFile != nullptr) + ContentFile->Flush(); + + if (found_message_start) + { + if (signed_message_not_on_first_line) + _error->Warning("Clearsigned file '%s' does not start with a signed message block.", InFile.c_str()); + else if (found_garbage) + _error->Warning("Clearsigned file '%s' contains unsigned lines.", InFile.c_str()); + } + + // An error occurred during reading - propagate it up + bool const hasErrored = _error->PendingError(); + _error->MergeWithStack(); + if (hasErrored) + return false; + + if (found_signature == true) + return _error->Error("Signature in file %s wasn't closed", InFile.c_str()); + + // if we haven't found any of them, this an unsigned file, + // so don't generate an error, but splitting was unsuccessful none-the-less + if (first_line == true && found_message_start == false && found_message_end == false) + return false; + // otherwise one missing indicates a syntax error + else if (first_line == true || found_message_start == false || found_message_end == false) + return _error->Error("Splitting of file %s failed as it doesn't contain all expected parts %i %i %i", InFile.c_str(), first_line, found_message_start, found_message_end); + + return true; +} + /*}}}*/ +bool OpenMaybeClearSignedFile(std::string const &ClearSignedFileName, FileFd &MessageFile) /*{{{*/ +{ + char * const message = GenerateTemporaryFileTemplate("fileutl.message"); + int const messageFd = mkstemp(message); + if (messageFd == -1) + { + free(message); + return _error->Errno("mkstemp", "Couldn't create temporary file to work with %s", ClearSignedFileName.c_str()); + } + // we have the fd, that's enough for us + unlink(message); + free(message); + + MessageFile.OpenDescriptor(messageFd, FileFd::ReadWrite | FileFd::BufferedWrite, true); + if (MessageFile.Failed() == true) + return _error->Error("Couldn't open temporary file to work with %s", ClearSignedFileName.c_str()); + + _error->PushToStack(); + bool const splitDone = SplitClearSignedFile(ClearSignedFileName, &MessageFile, NULL, NULL); + bool const errorDone = _error->PendingError(); + _error->MergeWithStack(); + if (splitDone == false) + { + MessageFile.Close(); + + if (errorDone == true) + return false; + + // we deal with an unsigned file + MessageFile.Open(ClearSignedFileName, FileFd::ReadOnly); + } + else // clear-signed + { + if (MessageFile.Seek(0) == false) + return _error->Errno("lseek", "Unable to seek back in message for file %s", ClearSignedFileName.c_str()); + } + + return MessageFile.Failed() == false; +} + /*}}}*/ |