X-Git-Url: https://git.saurik.com/apt.git/blobdiff_plain/b0d408547734100bf86781615f546487ecf390d9..42ba3fa1ec004acbddf5266559bd76428d904206:/methods/gpgv.cc diff --git a/methods/gpgv.cc b/methods/gpgv.cc index 014430041..60a7d4719 100644 --- a/methods/gpgv.cc +++ b/methods/gpgv.cc @@ -6,6 +6,7 @@ #include #include #include +#include "aptmethod.h" #include #include @@ -15,6 +16,11 @@ #include #include #include + +#include +#include +#include +#include #include #include #include @@ -26,6 +32,7 @@ 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" @@ -33,7 +40,63 @@ using std::vector; #define GNUPGREVKEYSIG "[GNUPG:] REVKEYSIG" #define GNUPGNODATA "[GNUPG:] NODATA" -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: string VerifyGetSigners(const char *file, const char *outfile, @@ -41,31 +104,20 @@ class GPGVMethod : public pkgAcqMethod vector &GoodSigners, vector &BadSigners, vector &WorthlessSigners, + vector &SoonWorthlessSigners, vector &NoPubKeySigners); - protected: - virtual bool URIAcquire(std::string const &Message, FetchItem *Itm); - virtual bool Configuration(string Message); + 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) {}; }; -bool GPGVMethod::Configuration(string Message) -{ - if (pkgAcqMethod::Configuration(Message) == false) - return false; - - DropPrivsOrDie(); - - return true; -} - string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, std::string const &key, vector &GoodSigners, vector &BadSigners, vector &WorthlessSigners, + vector &SoonWorthlessSigners, vector &NoPubKeySigners) { bool const Debug = _config->FindB("Debug::Acquire::gpgv", false); @@ -74,6 +126,7 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, std::clog << "inside VerifyGetSigners" << std::endl; int fd[2]; + bool const keyIsID = (key.empty() == false && key[0] != '/'); if (pipe(fd) < 0) return "Couldn't create pipe"; @@ -82,12 +135,14 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, if (pid < 0) return string("Couldn't spawn new process") + strerror(errno); else if (pid == 0) - ExecGPGV(outfile, file, 3, fd, key); + ExecGPGV(outfile, file, 3, fd, (keyIsID ? "" : key)); close(fd[1]); 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; while (1) @@ -107,32 +162,39 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, std::clog << "Got BADSIG! " << std::endl; BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX))); } - - if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0) + else if (strncmp(buffer, GNUPGERRSIG, sizeof(GNUPGERRSIG)-1) == 0) + { + if (Debug == true) + std::clog << "Got ERRSIG " << std::endl; + ErrSigners.push_back(string(buffer, strlen(GNUPGPREFIX), strlen("ERRSIG ") + 16)); + } + else if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0) { if (Debug == true) std::clog << "Got NO_PUBKEY " << std::endl; NoPubKeySigners.push_back(string(buffer+sizeof(GNUPGPREFIX))); + ErrSigners.erase(std::remove_if(ErrSigners.begin(), ErrSigners.end(), [&](std::string const &errsig) { + return errsig.compare(strlen("ERRSIG "), 16, buffer, strlen(GNUPGNOPUBKEY), 16) == 0; }), ErrSigners.end()); } - if (strncmp(buffer, GNUPGNODATA, sizeof(GNUPGBADSIG)-1) == 0) + else if (strncmp(buffer, GNUPGNODATA, sizeof(GNUPGBADSIG)-1) == 0) { if (Debug == true) std::clog << "Got NODATA! " << std::endl; BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX))); } - if (strncmp(buffer, GNUPGKEYEXPIRED, sizeof(GNUPGKEYEXPIRED)-1) == 0) + else if (strncmp(buffer, GNUPGKEYEXPIRED, sizeof(GNUPGKEYEXPIRED)-1) == 0) { if (Debug == true) std::clog << "Got KEYEXPIRED! " << std::endl; WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX))); } - if (strncmp(buffer, GNUPGREVKEYSIG, sizeof(GNUPGREVKEYSIG)-1) == 0) + else if (strncmp(buffer, GNUPGREVKEYSIG, sizeof(GNUPGREVKEYSIG)-1) == 0) { if (Debug == true) std::clog << "Got REVKEYSIG! " << std::endl; WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX))); } - if (strncmp(buffer, GNUPGGOODSIG, sizeof(GNUPGGOODSIG)-1) == 0) + else if (strncmp(buffer, GNUPGGOODSIG, sizeof(GNUPGGOODSIG)-1) == 0) { char *sig = buffer + sizeof(GNUPGPREFIX); char *p = sig + sizeof("GOODSIG"); @@ -143,9 +205,75 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, std::clog << "Got GOODSIG, key ID:" << sig << std::endl; GoodSigners.push_back(string(sig)); } + else if (strncmp(buffer, GNUPGVALIDSIG, sizeof(GNUPGVALIDSIG)-1) == 0) + { + char *sig = buffer + sizeof(GNUPGVALIDSIG); + std::istringstream iss((string(sig))); + vector tokens{std::istream_iterator{iss}, + std::istream_iterator{}}; + char *p = sig; + while (*p && isxdigit(*p)) + p++; + *p = 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({string(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(string(sig)); + GoodSigners.erase(std::remove_if(GoodSigners.begin(), GoodSigners.end(), [&](std::string const &goodsig) { + return IsTheSameKey(string(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(string(sig)); + } } fclose(pipein); free(buffer); + std::move(ErrSigners.begin(), ErrSigners.end(), std::back_inserter(WorthlessSigners)); + + // 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; + std::vector::iterator const foundItr = std::find(ValidSigners.begin(), ValidSigners.end(), key); + bool const found = (foundItr != ValidSigners.end()); + std::copy(GoodSigners.begin(), GoodSigners.end(), std::back_insert_iterator >(NoPubKeySigners)); + if (found) + { + // 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 goodlongkeyid = "GOODSIG " + key.substr(24, 16); + bool const foundGood = std::find(GoodSigners.begin(), GoodSigners.end(), goodlongkeyid) != GoodSigners.end(); + if (Debug == true) + std::clog << "Key " << key << " is valid sig, is " << goodlongkeyid << " also a good one? " << (foundGood ? "yes" : "no") << std::endl; + GoodSigners.clear(); + if (foundGood) + { + GoodSigners.push_back(goodlongkeyid); + NoPubKeySigners.erase(std::remove(NoPubKeySigners.begin(), NoPubKeySigners.end(), goodlongkeyid), NoPubKeySigners.end()); + } + } + else + GoodSigners.clear(); + } int status; waitpid(pid, &status, 0); @@ -153,11 +281,36 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, { ioprintf(std::clog, "gpgv exited with status %i\n", WEXITSTATUS(status)); } - + + if (Debug) + { + 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; + } + if (WEXITSTATUS(status) == 0) { - if (GoodSigners.empty()) - return _("Internal error: Good signature, but could not determine key fingerprint?!"); + 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) @@ -185,6 +338,7 @@ bool GPGVMethod::URIAcquire(std::string const &Message, FetchItem *Itm) vector BadSigners; // a worthless signature is a expired or revoked one vector WorthlessSigners; + vector SoonWorthlessSigners; vector NoPubKeySigners; FetchResult Res; @@ -194,7 +348,20 @@ bool GPGVMethod::URIAcquire(std::string const &Message, FetchItem *Itm) // 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, - NoPubKeySigners); + 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;