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// -*- 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;
}