X-Git-Url: https://git.saurik.com/apt.git/blobdiff_plain/7a8e00715588564a5b9434eaad65f2c6d3e513bb..5f060c2776606f3166bd6c64119c31be8ba5d857:/methods/gpgv.cc diff --git a/methods/gpgv.cc b/methods/gpgv.cc index 7e8500c51..70207e615 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 @@ -33,27 +39,68 @@ 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]; +}; + +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; +}; + +class GPGVMethod : public aptMethod { private: string VerifyGetSigners(const char *file, const char *outfile, - vector &GoodSigners, + 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) {}; }; 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); @@ -62,6 +109,7 @@ 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"; @@ -70,39 +118,19 @@ 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); + 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. - size_t buffersize = 64; - char *buffer = (char *) malloc(buffersize); - size_t bufferoff = 0; + std::vector ValidSigners; + size_t buffersize = 0; + char *buffer = NULL; while (1) { - int c; - - // Read a line. Sigh. - while ((c = getc(pipein)) != EOF && c != '\n') - { - if (bufferoff == buffersize) - { - char* newBuffer = (char *) realloc(buffer, buffersize *= 2); - if (newBuffer == NULL) - { - free(buffer); - return "Couldn't allocate a buffer big enough for reading"; - } - buffer = newBuffer; - } - *(buffer+bufferoff) = c; - bufferoff++; - } - if (bufferoff == 0 && c == EOF) - break; - *(buffer+bufferoff) = '\0'; - bufferoff = 0; + if (getline(&buffer, &buffersize, pipein) == -1) + break; if (Debug == true) std::clog << "Read: " << buffer << std::endl; @@ -116,32 +144,31 @@ 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, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0) { if (Debug == true) std::clog << "Got NO_PUBKEY " << std::endl; NoPubKeySigners.push_back(string(buffer+sizeof(GNUPGPREFIX))); } - 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"); @@ -152,10 +179,69 @@ 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; + if (Debug == true) + std::clog << "Got VALIDSIG, key ID: " << sig << std::endl; + // Reject weak digest algorithms + Digest digest = FindDigest(tokens[7]); + switch (digest.state) { + 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}); + 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(GoodSigners.begin(), GoodSigners.end(), string(sig))); + break; + case Digest::State::Trusted: + break; + } + + ValidSigners.push_back(string(sig)); + } } fclose(pipein); free(buffer); + // 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); if (Debug == true) @@ -165,8 +251,18 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, 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) @@ -185,15 +281,16 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, 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; @@ -201,9 +298,22 @@ bool GPGVMethod::Fetch(FetchItem *Itm) URIStart(Res); // 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(), + string msg = VerifyGetSigners(Path.c_str(), Itm->DestFile.c_str(), key, GoodSigners, BadSigners, WorthlessSigners, - NoPubKeySigners); + SoonWorthlessSigners, NoPubKeySigners); + + + // Check if there are any good signers that are not soon worthless + std::vector NotWarnAboutSigners(GoodSigners); + for (auto const & Signer : SoonWorthlessSigners) + NotWarnAboutSigners.erase(std::remove(NotWarnAboutSigners.begin(), NotWarnAboutSigners.end(), "GOODSIG " + Signer.key)); + // If all signers are soon worthless, report them. + if (NotWarnAboutSigners.empty()) { + 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; @@ -265,7 +375,5 @@ int main() GPGVMethod Mth; - Mth.DropPrivsOrDie(); - return Mth.Run(); }