X-Git-Url: https://git.saurik.com/apt.git/blobdiff_plain/16176b647e76f316ec98f31f6dd806a49d7b8a77..99ba7cc1901c761c97d67775f23858b86594f2ba:/methods/gpgv.cc diff --git a/methods/gpgv.cc b/methods/gpgv.cc index 5cb154f66..d073c733e 100644 --- a/methods/gpgv.cc +++ b/methods/gpgv.cc @@ -1,234 +1,399 @@ +#include + +#include #include -#include +#include #include -#include +#include +#include "aptmethod.h" -#include -#include -#include -#include -#include +#include #include +#include +#include +#include +#include #include +#include + +#include +#include +#include +#include #include +#include +#include + +#include + +using std::string; +using std::vector; #define GNUPGPREFIX "[GNUPG:]" #define GNUPGBADSIG "[GNUPG:] BADSIG" +#define GNUPGERRSIG "[GNUPG:] ERRSIG" #define GNUPGNOPUBKEY "[GNUPG:] NO_PUBKEY" #define GNUPGVALIDSIG "[GNUPG:] VALIDSIG" +#define GNUPGGOODSIG "[GNUPG:] GOODSIG" +#define GNUPGEXPKEYSIG "[GNUPG:] EXPKEYSIG" +#define GNUPGEXPSIG "[GNUPG:] EXPSIG" +#define GNUPGREVKEYSIG "[GNUPG:] REVKEYSIG" +#define GNUPGNODATA "[GNUPG:] NODATA" +#define APTKEYWARNING "[APTKEY:] WARNING" -class GPGVMethod : public pkgAcqMethod +struct Digest { + enum class State { + Untrusted, + Weak, + Trusted, + } state; + char name[32]; + + State getState() const { + std::string optionUntrusted; + std::string optionWeak; + strprintf(optionUntrusted, "APT::Hashes::%s::Untrusted", name); + strprintf(optionWeak, "APT::Hashes::%s::Weak", name); + if (_config->FindB(optionUntrusted, state == State::Untrusted) == true) + return State::Untrusted; + if (_config->FindB(optionWeak, state == State::Weak) == true) + return State::Weak; + + return state; + } +}; + +static constexpr Digest Digests[] = { + {Digest::State::Untrusted, "Invalid digest"}, + {Digest::State::Untrusted, "MD5"}, + {Digest::State::Weak, "SHA1"}, + {Digest::State::Weak, "RIPE-MD/160"}, + {Digest::State::Trusted, "Reserved digest"}, + {Digest::State::Trusted, "Reserved digest"}, + {Digest::State::Trusted, "Reserved digest"}, + {Digest::State::Trusted, "Reserved digest"}, + {Digest::State::Trusted, "SHA256"}, + {Digest::State::Trusted, "SHA384"}, + {Digest::State::Trusted, "SHA512"}, + {Digest::State::Trusted, "SHA224"}, +}; + +static Digest FindDigest(std::string const & Digest) +{ + int id = atoi(Digest.c_str()); + if (id >= 0 && static_cast(id) < _count(Digests)) { + return Digests[id]; + } else { + return Digests[0]; + } +} + +struct Signer { + std::string key; + std::string note; +}; +static bool IsTheSameKey(std::string const &validsig, std::string const &goodsig) { + // VALIDSIG reports a keyid (40 = 24 + 16), GOODSIG is a longid (16) only + return validsig.compare(24, 16, goodsig, strlen("GOODSIG "), 16) == 0; +} + +class GPGVMethod : public aptMethod { private: - const char *VerifyGetSigners(const char *file, const char *outfile, - vector &GoodSigners, vector &BadSigners, + string VerifyGetSigners(const char *file, const char *outfile, + std::string const &key, + vector &GoodSigners, + vector &BadSigners, + vector &WorthlessSigners, + vector &SoonWorthlessSigners, vector &NoPubKeySigners); - protected: - virtual bool Fetch(FetchItem *Itm); - + virtual bool URIAcquire(std::string const &Message, FetchItem *Itm) APT_OVERRIDE; public: - - GPGVMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig) {}; + GPGVMethod() : aptMethod("gpgv","1.0",SingleInstance | SendConfig) {}; }; - -const char *GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, +static void PushEntryWithKeyID(std::vector &Signers, char * const buffer, bool const Debug) +{ + char * const msg = buffer + sizeof(GNUPGPREFIX); + char *p = msg; + // skip the message + while (*p && !isspace(*p)) + ++p; + // skip the seperator whitespace + ++p; + // skip the hexdigit fingerprint + while (*p && isxdigit(*p)) + ++p; + // cut the rest from the message + *p = '\0'; + if (Debug == true) + std::clog << "Got " << msg << " !" << std::endl; + Signers.push_back(msg); +} +static void PushEntryWithUID(std::vector &Signers, char * const buffer, bool const Debug) +{ + std::string msg = buffer + sizeof(GNUPGPREFIX); + auto const nuke = msg.find_last_not_of("\n\t\r"); + if (nuke != std::string::npos) + msg.erase(nuke + 1); + if (Debug == true) + std::clog << "Got " << msg << " !" << std::endl; + Signers.push_back(msg); +} +string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, + std::string const &key, vector &GoodSigners, vector &BadSigners, + vector &WorthlessSigners, + vector &SoonWorthlessSigners, vector &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; - } + bool const Debug = DebugEnabled(); + + if (Debug == true) + std::clog << "inside VerifyGetSigners" << std::endl; - if (stat(pubringpath.c_str(), &buff) != 0) - return (string("Couldn't access keyring: ") + strerror(errno)).c_str(); + int fd[2]; + bool const keyIsID = (key.empty() == false && key[0] != '/'); if (pipe(fd) < 0) - { return "Couldn't create pipe"; - } - pid = fork(); + pid_t pid = fork(); if (pid < 0) - { - return (string("Couldn't spawn new process") + strerror(errno)).c_str(); - } + return string("Couldn't spawn new process") + strerror(errno); else if (pid == 0) - { - const char *Args[400]; - unsigned int i = 0; - - Args[i++] = gpgvpath.c_str(); - Args[i++] = "--status-fd"; - Args[i++] = "3"; - Args[i++] = "--keyring"; - Args[i++] = pubringpath.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[i++] = Opts->Value.c_str(); - if(i >= 395) { - std::cerr << _("E: Argument list from Acquire::gpgv::Options too long. Exiting.") << std::endl; - exit(111); - } - } - } - Args[i++] = file; - Args[i++] = outfile; - Args[i++] = NULL; - - if (_config->FindB("Debug::Acquire::gpgv", false)) - { - std::cerr << "Preparing to exec: " << gpgvpath; - for(unsigned int j=0;Args[j] != NULL; j++) - std::cerr << " " << Args[j]; - std::cerr << 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="); - execvp(gpgvpath.c_str(), (char **)Args); - - exit(111); - } + ExecGPGV(outfile, file, 3, fd, (keyIsID ? "" : key)); 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; + FILE *pipein = fdopen(fd[0], "r"); + + // Loop over the output of apt-key (which really is gnupg), and check the signatures. + std::vector ValidSigners; + std::vector ErrSigners; + size_t buffersize = 0; + char *buffer = NULL; + bool gotNODATA = false; 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; + if (getline(&buffer, &buffersize, pipein) == -1) + break; + if (Debug == true) + std::clog << "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) + PushEntryWithUID(BadSigners, buffer, Debug); + else if (strncmp(buffer, GNUPGERRSIG, sizeof(GNUPGERRSIG)-1) == 0) + PushEntryWithKeyID(ErrSigners, buffer, Debug); + else if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0) { - if (_config->FindB("Debug::Acquire::gpgv", false)) - std::cerr << "Got BADSIG! " << std::endl; - BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX))); + PushEntryWithKeyID(NoPubKeySigners, buffer, Debug); + ErrSigners.erase(std::remove_if(ErrSigners.begin(), ErrSigners.end(), [&](std::string const &errsig) { + return errsig.compare(strlen("ERRSIG "), 16, buffer, sizeof(GNUPGNOPUBKEY), 16) == 0; }), ErrSigners.end()); } - - if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0) + else if (strncmp(buffer, GNUPGNODATA, sizeof(GNUPGNODATA)-1) == 0) + gotNODATA = true; + else if (strncmp(buffer, GNUPGEXPKEYSIG, sizeof(GNUPGEXPKEYSIG)-1) == 0) + PushEntryWithUID(WorthlessSigners, buffer, Debug); + else if (strncmp(buffer, GNUPGEXPSIG, sizeof(GNUPGEXPSIG)-1) == 0) + PushEntryWithUID(WorthlessSigners, buffer, Debug); + else if (strncmp(buffer, GNUPGREVKEYSIG, sizeof(GNUPGREVKEYSIG)-1) == 0) + PushEntryWithUID(WorthlessSigners, buffer, Debug); + else if (strncmp(buffer, GNUPGGOODSIG, sizeof(GNUPGGOODSIG)-1) == 0) + PushEntryWithKeyID(GoodSigners, buffer, Debug); + else if (strncmp(buffer, GNUPGVALIDSIG, sizeof(GNUPGVALIDSIG)-1) == 0) { - if (_config->FindB("Debug::Acquire::gpgv", false)) - std::cerr << "Got NO_PUBKEY " << std::endl; - NoPubKeySigners.push_back(string(buffer+sizeof(GNUPGPREFIX))); + std::istringstream iss(buffer + sizeof(GNUPGVALIDSIG)); + vector tokens{std::istream_iterator{iss}, + std::istream_iterator{}}; + auto const sig = tokens[0]; + // Reject weak digest algorithms + Digest digest = FindDigest(tokens[7]); + switch (digest.getState()) { + case Digest::State::Weak: + // Treat them like an expired key: For that a message about expiry + // is emitted, a VALIDSIG, but no GOODSIG. + SoonWorthlessSigners.push_back({sig, digest.name}); + if (Debug == true) + std::clog << "Got weak VALIDSIG, key ID: " << sig << std::endl; + break; + case Digest::State::Untrusted: + // Treat them like an expired key: For that a message about expiry + // is emitted, a VALIDSIG, but no GOODSIG. + WorthlessSigners.push_back(sig); + GoodSigners.erase(std::remove_if(GoodSigners.begin(), GoodSigners.end(), [&](std::string const &goodsig) { + return IsTheSameKey(sig, goodsig); }), GoodSigners.end()); + if (Debug == true) + std::clog << "Got untrusted VALIDSIG, key ID: " << sig << std::endl; + break; + + case Digest::State::Trusted: + if (Debug == true) + std::clog << "Got trusted VALIDSIG, key ID: " << sig << std::endl; + break; + } + + ValidSigners.push_back(sig); } + else if (strncmp(buffer, APTKEYWARNING, sizeof(APTKEYWARNING)-1) == 0) + Warning("%s", buffer + sizeof(APTKEYWARNING)); + } + fclose(pipein); + free(buffer); + std::move(ErrSigners.begin(), ErrSigners.end(), std::back_inserter(WorthlessSigners)); - if (strncmp(buffer, GNUPGVALIDSIG, sizeof(GNUPGVALIDSIG)-1) == 0) + // apt-key has a --keyid parameter, but this requires gpg, so we call it without it + // and instead check after the fact which keyids where used for verification + if (keyIsID == true) + { + if (Debug == true) + std::clog << "GoodSigs needs to be limited to keyid " << key << std::endl; + bool foundGood = false; + for (auto const &k: VectorizeString(key, ',')) { - 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)); + if (std::find(ValidSigners.begin(), ValidSigners.end(), k) == ValidSigners.end()) + continue; + // we look for GOODSIG here as well as an expired sig is a valid sig as well (but not a good one) + std::string const goodfingerprint = "GOODSIG " + k; + std::string const goodlongkeyid = "GOODSIG " + k.substr(24, 16); + foundGood = std::find(GoodSigners.begin(), GoodSigners.end(), goodfingerprint) != GoodSigners.end(); + if (Debug == true) + std::clog << "Key " << k << " is valid sig, is " << goodfingerprint << " also a good one? " << (foundGood ? "yes" : "no") << std::endl; + std::string goodsig; + if (foundGood == false) + { + foundGood = std::find(GoodSigners.begin(), GoodSigners.end(), goodlongkeyid) != GoodSigners.end(); + if (Debug == true) + std::clog << "Key " << k << " is valid sig, is " << goodlongkeyid << " also a good one? " << (foundGood ? "yes" : "no") << std::endl; + goodsig = goodlongkeyid; + } + else + goodsig = goodfingerprint; + if (foundGood == false) + continue; + std::copy(GoodSigners.begin(), GoodSigners.end(), std::back_insert_iterator >(NoPubKeySigners)); + GoodSigners.clear(); + GoodSigners.push_back(goodsig); + NoPubKeySigners.erase( + std::remove(NoPubKeySigners.begin(), + std::remove(NoPubKeySigners.begin(), NoPubKeySigners.end(), goodfingerprint), + goodlongkeyid), + NoPubKeySigners.end() + ); + break; + } + if (foundGood == false) + { + std::copy(GoodSigners.begin(), GoodSigners.end(), std::back_insert_iterator >(NoPubKeySigners)); + GoodSigners.clear(); } } - fclose(pipein); + int status; waitpid(pid, &status, 0); - if (_config->FindB("Debug::Acquire::gpgv", false)) + if (Debug == true) { - std::cerr << "gpgv exited\n"; + ioprintf(std::clog, "gpgv exited with status %i\n", WEXITSTATUS(status)); } - - if (WEXITSTATUS(status) == 0) + + if (Debug) { - if (GoodSigners.empty()) - return _("Internal error: Good signature, but could not determine key fingerprint?!"); - return NULL; + std::cerr << "Summary:" << std::endl << " Good: "; + std::copy(GoodSigners.begin(), GoodSigners.end(), std::ostream_iterator(std::cerr, ", ")); + std::cerr << std::endl << " Bad: "; + std::copy(BadSigners.begin(), BadSigners.end(), std::ostream_iterator(std::cerr, ", ")); + std::cerr << std::endl << " Worthless: "; + std::copy(WorthlessSigners.begin(), WorthlessSigners.end(), std::ostream_iterator(std::cerr, ", ")); + std::cerr << std::endl << " SoonWorthless: "; + std::for_each(SoonWorthlessSigners.begin(), SoonWorthlessSigners.end(), [](Signer const &sig) { std::cerr << sig.key << ", "; }); + std::cerr << std::endl << " NoPubKey: "; + std::copy(NoPubKeySigners.begin(), NoPubKeySigners.end(), std::ostream_iterator(std::cerr, ", ")); + std::cerr << std::endl << " NODATA: " << (gotNODATA ? "yes" : "no") << std::endl; } - else if (WEXITSTATUS(status) == 1) + + if (WEXITSTATUS(status) == 112) { - return _("At least one invalid signature was encountered."); + // acquire system checks for "NODATA" to generate GPG errors (the others are only warnings) + std::string errmsg; + //TRANSLATORS: %s is a single techy word like 'NODATA' + strprintf(errmsg, _("Clearsigned file isn't valid, got '%s' (does the network require authentication?)"), "NODATA"); + return errmsg; } - else if (WEXITSTATUS(status) == 111) + else if (gotNODATA) { - // FIXME String concatenation considered harmful. - return (string(_("Could not execute ")) + gpgvpath + - string(_(" to verify signature (is gnupg installed?)"))).c_str(); + // acquire system checks for "NODATA" to generate GPG errors (the others are only warnings) + std::string errmsg; + //TRANSLATORS: %s is a single techy word like 'NODATA' + strprintf(errmsg, _("Signed file isn't valid, got '%s' (does the network require authentication?)"), "NODATA"); + return errmsg; } - else + else if (WEXITSTATUS(status) == 0) { - return _("Unknown error executing gpgv"); + if (keyIsID) + { + // gpgv will report success, but we want to enforce a certain keyring + // so if we haven't found the key the valid we found is in fact invalid + if (GoodSigners.empty()) + return _("At least one invalid signature was encountered."); + } + else + { + if (GoodSigners.empty()) + return _("Internal error: Good signature, but could not determine key fingerprint?!"); + } + return ""; } + else if (WEXITSTATUS(status) == 1) + return _("At least one invalid signature was encountered."); + else if (WEXITSTATUS(status) == 111) + return _("Could not execute 'apt-key' to verify signature (is gnupg installed?)"); + else + return _("Unknown error executing apt-key"); } -bool GPGVMethod::Fetch(FetchItem *Itm) +bool GPGVMethod::URIAcquire(std::string const &Message, FetchItem *Itm) { - URI Get = Itm->Uri; - string Path = Get.Host + Get.Path; // To account for relative paths - string keyID; + URI const Get = Itm->Uri; + string const Path = Get.Host + Get.Path; // To account for relative paths + std::string const key = LookupTag(Message, "Signed-By"); vector GoodSigners; vector BadSigners; + // a worthless signature is a expired or revoked one + vector WorthlessSigners; + vector SoonWorthlessSigners; vector 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); + // Run apt-key on file, extract contents and get the key ID of the signer + string msg = VerifyGetSigners(Path.c_str(), Itm->DestFile.c_str(), key, + GoodSigners, BadSigners, WorthlessSigners, + SoonWorthlessSigners, NoPubKeySigners); + + // Check if all good signers are soon worthless and warn in that case + if (std::all_of(GoodSigners.begin(), GoodSigners.end(), [&](std::string const &good) { + return std::any_of(SoonWorthlessSigners.begin(), SoonWorthlessSigners.end(), [&](Signer const &weak) { + return IsTheSameKey(weak.key, good); + }); + })) + { + for (auto const & Signer : SoonWorthlessSigners) + // TRANSLATORS: The second %s is the reason and is untranslated for repository owners. + Warning(_("Signature by key %s uses weak digest algorithm (%s)"), Signer.key.c_str(), Signer.note.c_str()); + } + 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()) + if (BadSigners.empty() && WorthlessSigners.empty() && NoPubKeySigners.empty()) errmsg = msg; else { @@ -236,49 +401,41 @@ bool GPGVMethod::Fetch(FetchItem *Itm) { errmsg += _("The following signatures were invalid:\n"); for (vector::iterator I = BadSigners.begin(); - I != BadSigners.end(); I++) + I != BadSigners.end(); ++I) + errmsg += (*I + "\n"); + } + if (!WorthlessSigners.empty()) + { + errmsg += _("The following signatures were invalid:\n"); + for (vector::iterator I = WorthlessSigners.begin(); + I != WorthlessSigners.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::iterator I = NoPubKeySigners.begin(); - I != NoPubKeySigners.end(); I++) + I != NoPubKeySigners.end(); ++I) errmsg += (*I + "\n"); } } - return _error->Error(errmsg.c_str()); + // this is only fatal if we have no good sigs or if we have at + // least one bad signature. good signatures and NoPubKey signatures + // happen easily when a file is signed with multiple signatures + if(GoodSigners.empty() or !BadSigners.empty()) + return _error->Error("%s", 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()); + std::move(BadSigners.begin(), BadSigners.end(), std::back_inserter(Res.GPGVOutput)); + std::move(NoPubKeySigners.begin(), NoPubKeySigners.end(), std::back_inserter(Res.GPGVOutput)); URIDone(Res); - if (_config->FindB("Debug::Acquire::gpgv", false)) - { - std::cerr << "gpgv succeeded\n"; - } + if (DebugEnabled()) + std::clog << "apt-key succeeded\n"; return true; } @@ -286,9 +443,5 @@ bool GPGVMethod::Fetch(FetchItem *Itm) int main() { - setlocale(LC_ALL, ""); - - GPGVMethod Mth; - - return Mth.Run(); + return GPGVMethod().Run(); }