@@ -20,18 +20,94 @@
#include <algorithm>
#include <fstream>
#include <iostream>
#include <memory>
#include <sstream>
#include <string>
#include <vector>
#include <apti18n.h>
/*}}}*/
static char * GenerateTemporaryFileTemplate(const char *basename) /*{{{*/
// syntactic sugar to wrap a raw pointer with a custom deleter in a std::unique_ptr
static std::unique_ptr<char, decltype(&free)> make_unique_char(void *const str = nullptr)
{
return {static_cast<char *>(str), &free};
}
static std::unique_ptr<FILE, decltype(&fclose)> make_unique_FILE(std::string const &filename, char const *const mode)
{
std::string out;
std::string tmpdir = GetTempDir();
strprintf(out, "%s/%s.XXXXXX", tmpdir.c_str(), basename);
return strdup(out.c_str());
return {fopen(filename.c_str(), mode), &fclose};
}
class LineBuffer /*{{{*/
{
char *buffer = nullptr;
size_t buffer_size = 0;
int line_length = 0;
// a "normal" find_last_not_of returns npos if not found
int find_last_not_of_length(APT::StringView const bad) const
{
for (int result = line_length - 1; result >= 0; --result)
if (bad.find(buffer[result]) == APT::StringView::npos)
return result + 1;
return 0;
}
public:
bool empty() const noexcept { return view().empty(); }
APT::StringView view() const noexcept { return {buffer, static_cast<size_t>(line_length)}; }
bool starts_with(APT::StringView const start) const { return view().substr(0, start.size()) == start; }
bool writeTo(FileFd *const to, size_t offset = 0) const
{
if (to == nullptr)
return true;
return to->Write(buffer + offset, line_length - offset);
}
bool writeLineTo(FileFd *const to) const
{
if (to == nullptr)
return true;
buffer[line_length] = '\n';
bool const result = to->Write(buffer, line_length + 1);
buffer[line_length] = '\0';
return result;
}
bool writeNewLineIf(FileFd *const to, bool const condition) const
{
if (not condition || to == nullptr)
return true;
return to->Write("\n", 1);
}
bool readFrom(FILE *stream, std::string const &InFile, bool acceptEoF = false)
{
errno = 0;
line_length = getline(&buffer, &buffer_size, stream);
if (errno != 0)
return _error->Errno("getline", "Could not read from %s", InFile.c_str());
if (line_length == -1)
{
if (acceptEoF)
return false;
return _error->Error("Splitting of clearsigned file %s failed as it doesn't contain all expected parts", InFile.c_str());
}
// a) remove newline characters, so we can work consistently with lines
line_length = find_last_not_of_length("\n\r");
// b) remove trailing whitespaces as defined by rfc4880 §7.1
line_length = find_last_not_of_length(" \t");
buffer[line_length] = '\0';
return true;
}
~LineBuffer() { free(buffer); }
};
static bool operator==(LineBuffer const &buf, APT::StringView const exp) noexcept
{
return buf.view() == exp;
}
static bool operator!=(LineBuffer const &buf, APT::StringView const exp) noexcept
{
return buf.view() != exp;
}
/*}}}*/
// ExecGPGV - returns the command needed for verify /*{{{*/
@@ -47,11 +123,10 @@ static char * GenerateTemporaryFileTemplate(const char *basename) /*{{{*/
*/
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);
auto S = make_unique_char(malloc(size) );
ssize_t const n = vsnprintf(S.get() , size, format, args);
if (n > -1 && n < size) {
out << S;
free(S);
out << S.get();
return true;
} else {
if (n > -1)
@@ -59,7 +134,6 @@ static bool iovprintf(std::ostream &out, const char *format,
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, ...)
@@ -73,7 +147,7 @@ static void APT_PRINTF(4) apt_error(std::ostream &outterm, int const statusfd, i
va_start(args,format);
ret = iovprintf(out, format, args, size);
va_end(args);
if (ret == true )
if (ret)
break;
}
if (statusfd != -1)
@@ -81,8 +155,8 @@ static void APT_PRINTF(4) apt_error(std::ostream &outterm, int const statusfd, i
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 )
if (not FileFd::Write(fd[1], errtag, strlen(errtag)) ||
not FileFd::Write(fd[1], errtext.data(), errtext.size()))
outterm << errtext << std::flush;
}
}
@@ -141,83 +215,134 @@ void ExecGPGV(std::string const &File, std::string const &FileGPG,
Opts = Opts->Child;
for (; Opts != 0; Opts = Opts->Next)
{
if (Opts->Value.empty() == true )
if (Opts->Value.empty())
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 ;
auto sig = make_unique_char() ;
auto data = make_unique_char() ;
auto conf = make_unique_char() ;
// Dump the configuration so apt-key picks up the correct Dir values
{
conf = GenerateTemporaryFileTemplate("apt.conf");
{
std::string tmpfile;
strprintf(tmpfile, "%s/apt.conf.XXXXXX", GetTempDir().c_str());
conf.reset(strdup(tmpfile.c_str()));
}
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);
int confFd = mkstemp(conf.get() );
if (confFd == -1) {
apt_error(std::cerr, statusfd, fd, "Couldn't create temporary file %s for passing config to apt-key", conf);
apt_error(std::cerr, statusfd, fd, "Couldn't create temporary file %s for passing config to apt-key", conf.get() );
local_exit(EINTERNAL);
}
local_exit.files.push_back(conf);
local_exit.files.push_back(conf.get() );
std::ofstream confStream(conf);
std::ofstream confStream(conf.get() );
close(confFd);
_config->Dump(confStream);
confStream.close();
setenv("APT_CONFIG", conf, 1);
setenv("APT_CONFIG", conf.get() , 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)
auto detached = make_unique_FILE(FileGPG, "r");
if (detached.get() == nullptr)
{
apt_error(std::cerr, statusfd, fd, "Couldn't create tempfile names for splitting up %s", File .c_str());
apt_error(std::cerr, statusfd, fd, "Detached signature file '%s' could not be opened", FileGPG.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)
LineBuffer buf;
bool open_signature = false;
bool found_badcontent = false;
size_t found_signatures = 0;
while (buf.readFrom(detached.get(), FileGPG, true))
{
apt_error(std::cerr, statusfd, fd, "Couldn't create tempfiles for splitting up %s", File.c_str());
local_exit(EINTERNAL);
if (open_signature)
{
if (buf == "-----END PGP SIGNATURE-----")
open_signature = false;
else if (buf.starts_with("-"))
{
// the used Radix-64 is not using dash for any value, so a valid line can't
// start with one. Header keys could, but no existent one does and seems unlikely.
// Instead it smells a lot like a header the parser didn't recognize.
apt_error(std::cerr, statusfd, fd, "Detached signature file '%s' contains unexpected line starting with a dash", FileGPG.c_str());
local_exit(112);
}
}
else //if (not open_signature)
{
if (buf == "-----BEGIN PGP SIGNATURE-----")
{
open_signature = true;
++found_signatures;
if (found_badcontent)
break;
}
else
{
found_badcontent = true;
if (found_signatures != 0)
break;
}
}
}
if (found_signatures == 0 && statusfd != -1)
{
// This is not an attack attempt but a file even gpgv would complain about
// likely the result of a paywall which is covered by the gpgv method
auto const errtag = "[GNUPG:] NODATA\n";
FileFd::Write(fd[1], errtag, strlen(errtag));
local_exit(113);
}
else if (found_badcontent)
{
apt_error(std::cerr, statusfd, fd, "Detached signature file '%s' contains lines not belonging to a signature", FileGPG.c_str());
local_exit(112);
}
if (open_signature)
{
apt_error(std::cerr, statusfd, fd, "Detached signature file '%s' contains unclosed signatures", FileGPG.c_str());
local_exit(112);
}
Args.push_back(FileGPG.c_str());
Args.push_back(File.c_str());
}
else // clear-signed file
{
FileFd signature;
signature.OpenDescriptor(sigFd, FileFd::WriteOnly, true);
if (GetTempFile("apt.sig", false, &signature) == nullptr)
local_exit(EINTERNAL);
sig.reset(strdup(signature.Name().c_str()));
local_exit.files.push_back(sig.get());
FileFd message;
message.OpenDescriptor(dataFd, FileFd::WriteOnly, true);
if (GetTempFile("apt.data", false, &message) == nullptr)
local_exit(EINTERNAL);
data.reset(strdup(message.Name().c_str()));
local_exit.files.push_back(data.get());
if (signature.Failed() == true || message.Failed() == true ||
SplitClearSignedFile(File, &message, nullptr, &signature) == false)
if (signature.Failed() || message.Failed() ||
not SplitClearSignedFile(File, &message, nullptr, &signature))
{
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(sig.get() );
Args.push_back(data.get() );
}
Args.push_back(NULL);
if (Debug == true)
if (Debug)
{
std::clog << "Preparing to exec: ";
for (std::vector<const char *>::const_iterator a = Args.begin(); *a != NULL; ++a)
@@ -270,7 +395,7 @@ void ExecGPGV(std::string const &File, std::string const &FileGPG,
}
// check if it exit'ed normally …
if (WIFEXITED(Status) == false )
if (not WIFEXITED(Status))
{
apt_error(std::cerr, statusfd, fd, _("Sub-process %s exited unexpectedly"), "apt-key");
local_exit(EINTERNAL);
@@ -289,168 +414,141 @@ void ExecGPGV(std::string const &File, std::string const &FileGPG,
}
/*}}}*/
// SplitClearSignedFile - split message into data/signature /*{{{*/
static int GetLineErrno(char **lineptr, size_t *n, FILE *stream, std::string const &InFile)
bool SplitClearSignedFile(std::string const &InFile, FileFd * const ContentFile,
std::vector<std::string> * const ContentHeader, FileFd * const SignatureFile)
{
int result;
auto in = make_unique_FILE(InFile, "r");
if (in.get() == nullptr)
return _error->Errno("fopen", "can not open %s", InFile.c_str());
errno = 0;
result = getline(lineptr, n, stream);
if (errno != 0)
struct ScopedErrors
{
ScopedErrors() { _error->PushToStack(); }
~ScopedErrors() { _error->MergeWithStack(); }
} scoped;
LineBuffer buf;
// start of the message
if (not buf.readFrom(in.get(), InFile))
return false; // empty or read error
if (buf != "-----BEGIN PGP SIGNED MESSAGE-----")
{
_error->Errno("getline", "Could not read from %s", InFile.c_str());
return -1;
// this might be an unsigned file we don't want to report errors for,
// but still finish unsuccessful none the less.
while (buf.readFrom(in.get(), InFile, true))
if (buf == "-----BEGIN PGP SIGNED MESSAGE-----")
return _error->Error("Clearsigned file '%s' does not start with a signed message block.", InFile.c_str());
return false;
}
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());
// save "Hash" Armor Headers
while (true)
{
if (not buf.readFrom(in.get(), InFile))
return false;
if (buf.empty())
break; // empty line ends the Armor Headers
if (buf.starts_with("-"))
// § 6.2 says unknown keys should be reported to the user. We don't go that far,
// but we assume that there will never be a header key starting with a dash
return _error->Error("Clearsigned file '%s' contains unexpected line starting with a dash (%s)", InFile.c_str(), "armor");
if (ContentHeader != nullptr && buf.starts_with("Hash: "))
ContentHeader->push_back(buf.view().to_string());
}
bool found_message_start = false;
bool found_message_end = false;
bool skip_until_empty_line = false;
bool found_signature = false;
// the message itself
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)
while (true)
{
_strrstrip(buf);
if (found_message_start == false)
if (not buf.readFrom(in.get(), InFile))
return false;
if (buf.starts_with("-"))
{
if (strcmp(buf, "-----BEGIN PGP SIGNED MESSAGE-----") == 0)
if (buf == "-----BEGIN PGP SIGNATURE-----")
{
if (not buf.writeLineTo(SignatureFile))
return false;
break;
}
else if (buf.starts_with("- "))
{
found_message_start = true;
skip_until_empty_line = true;
// we don't have any fields which need to be dash-escaped,
// but implementations are free to escape all lines …
if (not buf.writeNewLineIf(ContentFile, not first_line) || not buf.writeTo(ContentFile, 2))
return false;
}
else
signed_message_not_on_first_line = found_garbage = true;
// § 7.1 says a client should warn, but we don't really work with files which
// should contain lines starting with a dash, so it is a lot more likely that
// this is an attempt to trick our parser vs. gpgv parser into ignoring a header
return _error->Error("Clearsigned file '%s' contains unexpected line starting with a dash (%s)", InFile.c_str(), "msg");
}
else if (skip_until_empty_line == true)
else if (not buf.writeNewLineIf(ContentFile, not first_line) || not buf.writeTo(ContentFile))
return false;
first_line = false;
}
// collect all signatures
bool open_signature = true;
while (true)
{
if (not buf.readFrom(in.get(), InFile, true))
break;
if (open_signature)
{
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);
if (buf == "-----END PGP SIGNATURE-----")
open_signature = false;
else if (buf.starts_with("-"))
// the used Radix-64 is not using dash for any value, so a valid line can't
// start with one. Header keys could, but no existent one does and seems unlikely.
// Instead it smells a lot like a header the parser didn't recognize.
return _error->Error("Clearsigned file '%s' contains unexpected line starting with a dash (%s)", InFile.c_str(), "sig");
}
else if (found_signature == false)
else //if (not open_signatur e)
{
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));
}
if (buf == "-----BEGIN PGP SIGNATURE-----")
open_signature = true;
else
found_garbage = true ;
return _error->Error("Clearsigned file '%s' contains unsigned lines.", InFile.c_str());
}
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;
if (not buf.writeLineTo(SignatureFile))
return false;
}
fclose(in);
if (buf != NULL)
free(buf);
if (open_signature)
return _error->Error("Signature in file %s wasn't closed", InFile.c_str());
// Flush the files. Errors will be checked below.
// Flush the files
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)
// Catch-all for "unhandled" read/sync errors
if (_error->PendingError())
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)
if (GetTempFile("clearsigned.message", true, &MessageFile) == nullptr)
return false;
if (MessageFile.Failed())
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 == fals e)
if (not splitDone)
{
MessageFile.Close();
if (errorDone == true )
if (errorDone)
return false;
// we deal with an unsigned file
@@ -458,10 +556,10 @@ bool OpenMaybeClearSignedFile(std::string const &ClearSignedFileName, FileFd &Me
}
else // clear-signed
{
if (MessageFile.Seek(0) == false )
if (not MessageFile.Seek(0))
return _error->Errno("lseek", "Unable to seek back in message for file %s", ClearSignedFileName.c_str());
}
return MessageFile.Failed() == false ;
return not MessageFile.Failed();
}
/*}}}*/