From ff8fa4ab4b80384a9240f0df63181f71077a8d83 Mon Sep 17 00:00:00 2001 From: David Kalnischkies Date: Fri, 17 Aug 2018 11:59:45 +0200 Subject: Support subkeys properly in Signed-By options If we limit a file to be signed by a certain key it should usually accept also being signed by any of this keys subkeys instead of requiring each subkey to be listed explicitly. If the later is really wanted we support now also the same syntax as gpg does with appending an exclamation mark at the end of the fingerprint to force no mapping. --- apt-pkg/deb/debmetaindex.cc | 113 ++++++++++++++----------- methods/gpgv.cc | 44 ++++++++-- test/integration/framework | 1 + test/integration/sebastiansubkey.master.sec | Bin 0 -> 4829 bytes test/integration/sebastiansubkey.pub | Bin 0 -> 2567 bytes test/integration/sebastiansubkey.sec | Bin 0 -> 3546 bytes test/integration/test-method-gpgv | 33 +++++++- test/integration/test-releasefile-verification | 38 +++++++++ test/integration/test-signed-by-option | 22 ++++- 9 files changed, 190 insertions(+), 61 deletions(-) create mode 100644 test/integration/sebastiansubkey.master.sec create mode 100644 test/integration/sebastiansubkey.pub create mode 100644 test/integration/sebastiansubkey.sec diff --git a/apt-pkg/deb/debmetaindex.cc b/apt-pkg/deb/debmetaindex.cc index 9c7c70784..1afcdf2c0 100644 --- a/apt-pkg/deb/debmetaindex.cc +++ b/apt-pkg/deb/debmetaindex.cc @@ -28,6 +28,57 @@ #include +static std::string transformFingergrpints(std::string finger) /*{{{*/ +{ + std::transform(finger.begin(), finger.end(), finger.begin(), ::toupper); + if (finger.length() == 40) + { + if (finger.find_first_not_of("0123456789ABCDEF") == std::string::npos) + return finger; + } + else if (finger.length() == 41) + { + auto bang = finger.find_first_not_of("0123456789ABCDEF"); + if (bang == 40 && finger[bang] == '!') + return finger; + } + return ""; +} + /*}}}*/ +static std::string transformFingergrpintsWithFilenames(std::string const &finger) /*{{{*/ +{ + // no check for existence as we could be chrooting later or such things + if (finger.empty() == false && finger[0] == '/') + return finger; + return transformFingergrpints(finger); +} + /*}}}*/ +static std::string NormalizeSignedBy(std::string SignedBy, bool const SupportFilenames) /*{{{*/ +{ + // we could go all fancy and allow short/long/string matches as gpgv/apt-key does, + // but fingerprints are harder to fake than the others and this option is set once, + // not interactively all the time so easy to type is not really a concern. + std::transform(SignedBy.begin(), SignedBy.end(), SignedBy.begin(), [](char const c) { + return (isspace(c) == 0) ? c : ','; + }); + auto fingers = VectorizeString(SignedBy, ','); + auto const isAnEmptyString = [](std::string const &s) { return s.empty(); }; + fingers.erase(std::remove_if(fingers.begin(), fingers.end(), isAnEmptyString), fingers.end()); + if (unlikely(fingers.empty())) + return ""; + if (SupportFilenames) + std::transform(fingers.begin(), fingers.end(), fingers.begin(), transformFingergrpintsWithFilenames); + else + std::transform(fingers.begin(), fingers.end(), fingers.begin(), transformFingergrpints); + if (std::any_of(fingers.begin(), fingers.end(), isAnEmptyString)) + return ""; + std::stringstream os; + std::copy(fingers.begin(), fingers.end() - 1, std::ostream_iterator(os, ",")); + os << *fingers.rbegin(); + return os.str(); +} + /*}}}*/ + class APT_HIDDEN debReleaseIndexPrivate /*{{{*/ { public: @@ -566,26 +617,9 @@ bool debReleaseIndex::Load(std::string const &Filename, std::string * const Erro auto Sign = Section.FindS("Signed-By"); if (Sign.empty() == false) { - std::transform(Sign.begin(), Sign.end(), Sign.begin(), [&](char const c) { - return (isspace(c) == 0) ? c : ','; - }); - auto fingers = VectorizeString(Sign, ','); - std::transform(fingers.begin(), fingers.end(), fingers.begin(), [&](std::string finger) { - std::transform(finger.begin(), finger.end(), finger.begin(), ::toupper); - if (finger.length() != 40 || finger.find_first_not_of("0123456789ABCDEF") != std::string::npos) - { - if (ErrorText != NULL) - strprintf(*ErrorText, _("Invalid '%s' entry in Release file %s"), "Signed-By", Filename.c_str()); - return std::string(); - } - return finger; - }); - if (fingers.empty() == false && std::find(fingers.begin(), fingers.end(), "") == fingers.end()) - { - std::stringstream os; - std::copy(fingers.begin(), fingers.end(), std::ostream_iterator(os, ",")); - SignedBy = os.str(); - } + SignedBy = NormalizeSignedBy(Sign, false); + if (SignedBy.empty() && ErrorText != NULL) + strprintf(*ErrorText, _("Invalid '%s' entry in Release file %s"), "Signed-By", Filename.c_str()); } if (AuthPossible) @@ -737,38 +771,15 @@ bool debReleaseIndex::SetSignedBy(std::string const &pSignedBy) { if (SignedBy.empty() == true && pSignedBy.empty() == false) { - if (pSignedBy[0] == '/') // no check for existence as we could be chrooting later or such things - SignedBy = pSignedBy; // absolute path to a keyring file - else - { - // we could go all fancy and allow short/long/string matches as gpgv/apt-key does, - // but fingerprints are harder to fake than the others and this option is set once, - // not interactively all the time so easy to type is not really a concern. - auto fingers = VectorizeString(pSignedBy, ','); - std::transform(fingers.begin(), fingers.end(), fingers.begin(), [&](std::string finger) { - std::transform(finger.begin(), finger.end(), finger.begin(), ::toupper); - if (finger.length() != 40 || finger.find_first_not_of("0123456789ABCDEF") != std::string::npos) - { - _error->Error(_("Invalid value set for option %s regarding source %s %s (%s)"), "Signed-By", URI.c_str(), Dist.c_str(), "not a fingerprint"); - return std::string(); - } - return finger; - }); - std::stringstream os; - std::copy(fingers.begin(), fingers.end(), std::ostream_iterator(os, ",")); - SignedBy = os.str(); - } - // Normalize the string: Remove trailing commas - while (SignedBy[SignedBy.size() - 1] == ',') - SignedBy.resize(SignedBy.size() - 1); + SignedBy = NormalizeSignedBy(pSignedBy, true); + if (SignedBy.empty()) + _error->Error(_("Invalid value set for option %s regarding source %s %s (%s)"), "Signed-By", URI.c_str(), Dist.c_str(), "not a fingerprint"); } - else { - // Only compare normalized strings - auto pSignedByView = APT::StringView(pSignedBy); - while (pSignedByView[pSignedByView.size() - 1] == ',') - pSignedByView = pSignedByView.substr(0, pSignedByView.size() - 1); - if (pSignedByView != SignedBy) - return _error->Error(_("Conflicting values set for option %s regarding source %s %s: %s != %s"), "Signed-By", URI.c_str(), Dist.c_str(), SignedBy.c_str(), pSignedByView.to_string().c_str()); + else + { + auto const normalSignedBy = NormalizeSignedBy(pSignedBy, true); + if (normalSignedBy != SignedBy) + return _error->Error(_("Conflicting values set for option %s regarding source %s %s: %s != %s"), "Signed-By", URI.c_str(), Dist.c_str(), SignedBy.c_str(), normalSignedBy.c_str()); } return true; } diff --git a/methods/gpgv.cc b/methods/gpgv.cc index 84b8c3e59..e2a20722b 100644 --- a/methods/gpgv.cc +++ b/methods/gpgv.cc @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -175,6 +176,7 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, // Loop over the output of apt-key (which really is gnupg), and check the signatures. std::vector ValidSigners; std::vector ErrSigners; + std::map> SubKeyMapping; size_t buffersize = 0; char *buffer = NULL; bool gotNODATA = false; @@ -242,6 +244,9 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, } ValidSigners.push_back(sig); + + if (tokens.size() > 9 && sig != tokens[9]) + SubKeyMapping[tokens[9]].emplace_back(sig); } else if (strncmp(buffer, APTKEYWARNING, sizeof(APTKEYWARNING)-1) == 0) Warning("%s", buffer + sizeof(APTKEYWARNING)); @@ -265,15 +270,38 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile, if (Debug == true) std::clog << "Key " << good << " is good sig, is it also a valid and allowed one? "; bool found = false; - for (auto const &l : limitedTo) + for (auto l : limitedTo) { - if (IsTheSameKey(l, good) == false) - continue; - // GOODSIG might be "just" a longid, so we check VALIDSIG which is always a fingerprint - if (std::find(ValidSigners.begin(), ValidSigners.end(), l) == ValidSigners.end()) - continue; - found = true; - break; + bool exactKey = false; + if (APT::String::Endswith(l, "!")) + { + exactKey = true; + l.erase(l.length() - 1); + } + if (IsTheSameKey(l, good)) + { + // GOODSIG might be "just" a longid, so we check VALIDSIG which is always a fingerprint + if (std::find(ValidSigners.cbegin(), ValidSigners.cend(), l) == ValidSigners.cend()) + continue; + found = true; + break; + } + else if (exactKey == false) + { + auto const master = SubKeyMapping.find(l); + if (master == SubKeyMapping.end()) + continue; + for (auto const &sub : master->second) + if (IsTheSameKey(sub, good)) + { + if (std::find(ValidSigners.cbegin(), ValidSigners.cend(), sub) == ValidSigners.cend()) + continue; + found = true; + break; + } + if (found) + break; + } } if (Debug) std::clog << (found ? "yes" : "no") << "\n"; diff --git a/test/integration/framework b/test/integration/framework index b0456096c..8ec2e80cf 100644 --- a/test/integration/framework +++ b/test/integration/framework @@ -1988,6 +1988,7 @@ mapkeynametokeyid() { *Joe*|*Sixpack*|newarchive) echo '5A90D141DBAC8DAE';; *Rex*|*Expired*) echo '4BC0A39C27CE74F9';; *Marvin*|*Paranoid*) echo 'E8525D47528144E2';; + *Sebastian*|*Subkey*) echo '5B6896415D44C43E';; oldarchive) echo 'FDD2DB85F68C85A3';; *) echo 'UNKNOWN KEY';; esac diff --git a/test/integration/sebastiansubkey.master.sec b/test/integration/sebastiansubkey.master.sec new file mode 100644 index 000000000..4d86fb983 Binary files /dev/null and b/test/integration/sebastiansubkey.master.sec differ diff --git a/test/integration/sebastiansubkey.pub b/test/integration/sebastiansubkey.pub new file mode 100644 index 000000000..c5f198c77 Binary files /dev/null and b/test/integration/sebastiansubkey.pub differ diff --git a/test/integration/sebastiansubkey.sec b/test/integration/sebastiansubkey.sec new file mode 100644 index 000000000..fd40889da Binary files /dev/null and b/test/integration/sebastiansubkey.sec differ diff --git a/test/integration/test-method-gpgv b/test/integration/test-method-gpgv index 5e00b1f13..2b53648f0 100755 --- a/test/integration/test-method-gpgv +++ b/test/integration/test-method-gpgv @@ -40,6 +40,11 @@ testrun() { testgpgv 'Good signed with fingerprint' 'Good: GOODSIG 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE,' '[GNUPG:] GOODSIG 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE Joe Sixpack (APT Testcases Dummy) [GNUPG:] VALIDSIG 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE 2016-09-01 1472742625 0 4 0 1 11 00 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE' + testgpgv 'Good subkey signed with long keyid' 'Good: GOODSIG 5B6896415D44C43E,' '[GNUPG:] GOODSIG 5B6896415D44C43E Sebastian Subkey +[GNUPG:] VALIDSIG 4281DEDBD466EAE8C1F4157E5B6896415D44C43E 2018-08-16 1534459673 0 4 0 1 11 00 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE' + testgpgv 'Good subkey signed with fingerprint' 'Good: GOODSIG 4281DEDBD466EAE8C1F4157E5B6896415D44C43E,' '[GNUPG:] GOODSIG 4281DEDBD466EAE8C1F4157E5B6896415D44C43E Sebastian Subkey +[GNUPG:] VALIDSIG 4281DEDBD466EAE8C1F4157E5B6896415D44C43E 2018-08-16 1534459673 0 4 0 1 11 00 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE' + testgpgv 'Untrusted signed with long keyid' 'Worthless: 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE,' '[GNUPG:] GOODSIG 5A90D141DBAC8DAE Joe Sixpack (APT Testcases Dummy) [GNUPG:] VALIDSIG 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE 2016-09-01 1472742625 0 4 0 1 1 00 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE' testsuccess grep '^\s\+Good:\s\+$' method.output @@ -96,7 +101,33 @@ testgpgv 'Good signed with long keyid but not signed-by key' 'NoPubKey: GOODSIG [GNUPG:] VALIDSIG 891CC50E605796A0C6E733F74BC0A39C27CE74F9 2016-09-01 1472742625 0 4 0 1 11 00 891CC50E605796A0C6E733F74BC0A39C27CE74F9' testsuccess grep '^\s\+Good:\s\+$' method.output testsuccess grep 'verified because the public key is not available: GOODSIG' method.output -testgpgv 'Good signed with fingerprint' 'NoPubKey: GOODSIG 891CC50E605796A0C6E733F74BC0A39C27CE74F9,' '[GNUPG:] GOODSIG 891CC50E605796A0C6E733F74BC0A39C27CE74F9 Rex Expired +testgpgv 'Good signed with fingerprint but not signed-by key' 'NoPubKey: GOODSIG 891CC50E605796A0C6E733F74BC0A39C27CE74F9,' '[GNUPG:] GOODSIG 891CC50E605796A0C6E733F74BC0A39C27CE74F9 Rex Expired [GNUPG:] VALIDSIG 891CC50E605796A0C6E733F74BC0A39C27CE74F9 2016-09-01 1472742625 0 4 0 1 11 00 891CC50E605796A0C6E733F74BC0A39C27CE74F9' testsuccess grep '^\s\+Good:\s\+$' method.output testsuccess grep 'verified because the public key is not available: GOODSIG' method.output + +gpgvmethod() { + echo '601 Configuration +Config-Item: Debug::Acquire::gpgv=1 +Config-Item: Dir::Bin::apt-key=./faked-apt-key +Config-Item: APT::Hashes::SHA1::Weak=true + +600 URI Acquire +URI: file:///dev/null +Filename: /dev/zero +Signed-By: 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE! +' | runapt "${METHODSDIR}/gpgv" +} +testgpgv 'Exact matched subkey signed with long keyid' 'Good: GOODSIG 5A90D141DBAC8DAE,' '[GNUPG:] GOODSIG 5A90D141DBAC8DAE Sebastian Subkey +[GNUPG:] VALIDSIG 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE 2018-08-16 1534459673 0 4 0 1 11 00 4281DEDBD466EAE8C1F4157E5B6896415D44C43E' +testgpgv 'Exact matched subkey signed with fingerprint' 'Good: GOODSIG 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE,' '[GNUPG:] GOODSIG 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE Sebastian Subkey +[GNUPG:] VALIDSIG 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE 2018-08-16 1534459673 0 4 0 1 11 00 4281DEDBD466EAE8C1F4157E5B6896415D44C43E' + +testgpgv 'Exact unmatched subkey signed with long keyid' 'NoPubKey: GOODSIG 5B6896415D44C43E,' '[GNUPG:] GOODSIG 5B6896415D44C43E Sebastian Subkey +[GNUPG:] VALIDSIG 4281DEDBD466EAE8C1F4157E5B6896415D44C43E 2018-08-16 1534459673 0 4 0 1 11 00 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE' +testsuccess grep '^\s\+Good:\s\+$' method.output +testsuccess grep 'verified because the public key is not available: GOODSIG' method.output +testgpgv 'Exact unmatched subkey signed with fingerprint' 'NoPubKey: GOODSIG 4281DEDBD466EAE8C1F4157E5B6896415D44C43E,' '[GNUPG:] GOODSIG 4281DEDBD466EAE8C1F4157E5B6896415D44C43E Sebastian Subkey +[GNUPG:] VALIDSIG 4281DEDBD466EAE8C1F4157E5B6896415D44C43E 2018-08-16 1534459673 0 4 0 1 11 00 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE' +testsuccess grep '^\s\+Good:\s\+$' method.output +testsuccess grep 'verified because the public key is not available: GOODSIG' method.output diff --git a/test/integration/test-releasefile-verification b/test/integration/test-releasefile-verification index 36a90f9d5..f61d93f79 100755 --- a/test/integration/test-releasefile-verification +++ b/test/integration/test-releasefile-verification @@ -342,6 +342,44 @@ Signed-By: ${MARVIN} ${MARVIN}, \\ testsuccessequal "$(cat "${PKGFILE}-new") " aptcache show apt installaptnew + + cp -a keys/sebastiansubkey.pub rootdir/etc/apt/trusted.gpg.d/sebastiansubkey.gpg + local SEBASTIAN="$(aptkey --keyring keys/sebastiansubkey.pub finger --with-colons | grep -m 1 '^fpr' | cut -d':' -f 10)" + msgmsg 'Warm archive with subkey signing' 'Sebastian Subkey' + rm -rf rootdir/var/lib/apt/lists + cp -a rootdir/var/lib/apt/lists-bak rootdir/var/lib/apt/lists + signreleasefiles 'Sebastian Subkey' + sed -i "/^Valid-Until: / a\ +Signed-By: ${SEBASTIAN}" rootdir/var/lib/apt/lists/*Release + touch -d 'now - 1 year' rootdir/var/lib/apt/lists/*Release + successfulaptgetupdate + testsuccessequal "$(cat "${PKGFILE}-new") +" aptcache show apt + installaptnew + + msgmsg 'Warm archive with wrong exact subkey signing' 'Sebastian Subkey' + rm -rf rootdir/var/lib/apt/lists + cp -a rootdir/var/lib/apt/lists-bak rootdir/var/lib/apt/lists + sed -i "/^Valid-Until: / a\ +Signed-By: ${SEBASTIAN}!" rootdir/var/lib/apt/lists/*Release + touch -d 'now - 1 year' rootdir/var/lib/apt/lists/*Release + updatewithwarnings 'W: .* public key is not available: GOODSIG' + testsuccessequal "$(cat "${PKGFILE}") +" aptcache show apt + installaptold + + local SUBKEY="$(aptkey --keyring keys/sebastiansubkey.pub finger --with-colons | grep -m 2 '^fpr' | tail -n -1 | cut -d':' -f 10)" + msgmsg 'Warm archive with correct exact subkey signing' 'Sebastian Subkey' + rm -rf rootdir/var/lib/apt/lists + cp -a rootdir/var/lib/apt/lists-bak rootdir/var/lib/apt/lists + sed -i "/^Valid-Until: / a\ +Signed-By: ${SUBKEY}!" rootdir/var/lib/apt/lists/*Release + touch -d 'now - 1 year' rootdir/var/lib/apt/lists/*Release + successfulaptgetupdate + testsuccessequal "$(cat "${PKGFILE}-new") +" aptcache show apt + installaptnew + rm -f rootdir/etc/apt/trusted.gpg.d/sebastiansubkey.gpg } runtest2() { diff --git a/test/integration/test-signed-by-option b/test/integration/test-signed-by-option index 4ab2e28bb..faa7dec44 100755 --- a/test/integration/test-signed-by-option +++ b/test/integration/test-signed-by-option @@ -7,7 +7,27 @@ TESTDIR="$(readlink -f "$(dirname "$0")")" setupenvironment configarchitecture 'amd64' -msgtest "Check that a repository with signed-by and two components works" +msgtest 'Check that a repository with' 'signed-by and two components works' echo 'deb [signed-by=CDE5618B8805FD6E202CE9C2D73C39E56580B386] https://people.debian.org/~jak/debian/ stable main contrib # Äffchen' > rootdir/etc/apt/sources.list +testsuccess --nomsg aptcache policy + +msgtest 'Check that a repository with' 'two fingerprints work' +echo 'deb [signed-by=CDE5618B8805FD6E202CE9C2D73C39E56580B386,AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA] https://people.debian.org/~jak/debian/ stable main contrib # Äffchen' > rootdir/etc/apt/sources.list +testsuccess --nomsg aptcache policy + +msgtest 'Check that a repository with' 'exact fingerprint works' +echo 'deb [signed-by=CDE5618B8805FD6E202CE9C2D73C39E56580B386!] https://people.debian.org/~jak/debian/ stable main contrib # Äffchen' > rootdir/etc/apt/sources.list +testsuccess --nomsg aptcache policy +msgtest 'Check that a repository with' 'whitespaced fingerprints work' +echo 'deb [signed-by=CDE5618B8805FD6E202CE9C2D73C39E56580B386!,,,,AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA] https://people.debian.org/~jak/debian/ stable main contrib # Äffchen' > rootdir/etc/apt/sources.list +cat > rootdir/etc/apt/sources.list.d/people.sources <