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git-commit-vandalism/t/t7416-submodule-dash-url.sh

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submodule-config: ban submodule urls that start with dash The previous commit taught the submodule code to invoke our "git clone $url $path" with a "--" separator so that we aren't confused by urls or paths that start with dashes. However, that's just one code path. It's not clear if there are others, and it would be an easy mistake to add one in the future. Moreover, even with the fix in the previous commit, it's quite hard to actually do anything useful with such an entry. Any url starting with a dash must fall into one of three categories: - it's meant as a file url, like "-path". But then any clone is not going to have the matching path, since it's by definition relative inside the newly created clone. If you spell it as "./-path", the submodule code sees the "/" and translates this to an absolute path, so it at least works (assuming the receiver has the same filesystem layout as you). But that trick does not apply for a bare "-path". - it's meant as an ssh url, like "-host:path". But this already doesn't work, as we explicitly disallow ssh hostnames that begin with a dash (to avoid option injection against ssh). - it's a remote-helper scheme, like "-scheme::data". This _could_ work if the receiver bends over backwards and creates a funny-named helper like "git-remote--scheme". But normally there would not be any helper that matches. Since such a url does not work today and is not likely to do anything useful in the future, let's simply disallow them entirely. That protects the existing "git clone" path (in a belt-and-suspenders way), along with any others that might exist. Our tests cover two cases: 1. A file url with "./" continues to work, showing that there's an escape hatch for people with truly silly repo names. 2. A url starting with "-" is rejected. Note that we expect case (2) to fail, but it would have done so even without this commit, for the reasons given above. So instead of just expecting failure, let's also check for the magic word "ignoring" on stderr. That lets us know that we failed for the right reason. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-24 10:36:30 +02:00
#!/bin/sh
fsck: detect gitmodules URLs with embedded newlines The credential protocol can't handle values with newlines. We already detect and block any such URLs from being used with credential helpers, but let's also add an fsck check to detect and block gitmodules files with such URLs. That will let us notice the problem earlier when transfer.fsckObjects is turned on. And in particular it will prevent bad objects from spreading, which may protect downstream users running older versions of Git. We'll file this under the existing gitmodulesUrl flag, which covers URLs with option injection. There's really no need to distinguish the exact flaw in the URL in this context. Likewise, I've expanded the description of t7416 to cover all types of bogus URLs.
2020-03-11 23:48:24 +01:00
test_description='check handling of disallowed .gitmodule urls'
submodule-config: ban submodule urls that start with dash The previous commit taught the submodule code to invoke our "git clone $url $path" with a "--" separator so that we aren't confused by urls or paths that start with dashes. However, that's just one code path. It's not clear if there are others, and it would be an easy mistake to add one in the future. Moreover, even with the fix in the previous commit, it's quite hard to actually do anything useful with such an entry. Any url starting with a dash must fall into one of three categories: - it's meant as a file url, like "-path". But then any clone is not going to have the matching path, since it's by definition relative inside the newly created clone. If you spell it as "./-path", the submodule code sees the "/" and translates this to an absolute path, so it at least works (assuming the receiver has the same filesystem layout as you). But that trick does not apply for a bare "-path". - it's meant as an ssh url, like "-host:path". But this already doesn't work, as we explicitly disallow ssh hostnames that begin with a dash (to avoid option injection against ssh). - it's a remote-helper scheme, like "-scheme::data". This _could_ work if the receiver bends over backwards and creates a funny-named helper like "git-remote--scheme". But normally there would not be any helper that matches. Since such a url does not work today and is not likely to do anything useful in the future, let's simply disallow them entirely. That protects the existing "git clone" path (in a belt-and-suspenders way), along with any others that might exist. Our tests cover two cases: 1. A file url with "./" continues to work, showing that there's an escape hatch for people with truly silly repo names. 2. A url starting with "-" is rejected. Note that we expect case (2) to fail, but it would have done so even without this commit, for the reasons given above. So instead of just expecting failure, let's also check for the magic word "ignoring" on stderr. That lets us know that we failed for the right reason. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-24 10:36:30 +02:00
. ./test-lib.sh
test_expect_success 'create submodule with protected dash in url' '
git init upstream &&
git -C upstream commit --allow-empty -m base &&
mv upstream ./-upstream &&
git submodule add ./-upstream sub &&
git add sub .gitmodules &&
git commit -m submodule
'
test_expect_success 'clone can recurse submodule' '
test_when_finished "rm -rf dst" &&
git clone --recurse-submodules . dst &&
echo base >expect &&
git -C dst/sub log -1 --format=%s >actual &&
test_cmp expect actual
'
fsck: detect submodule urls starting with dash Urls with leading dashes can cause mischief on older versions of Git. We should detect them so that they can be rejected by receive.fsckObjects, preventing modern versions of git from being a vector by which attacks can spread. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-24 10:37:17 +02:00
test_expect_success 'fsck accepts protected dash' '
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
git push dst HEAD
'
submodule-config: ban submodule urls that start with dash The previous commit taught the submodule code to invoke our "git clone $url $path" with a "--" separator so that we aren't confused by urls or paths that start with dashes. However, that's just one code path. It's not clear if there are others, and it would be an easy mistake to add one in the future. Moreover, even with the fix in the previous commit, it's quite hard to actually do anything useful with such an entry. Any url starting with a dash must fall into one of three categories: - it's meant as a file url, like "-path". But then any clone is not going to have the matching path, since it's by definition relative inside the newly created clone. If you spell it as "./-path", the submodule code sees the "/" and translates this to an absolute path, so it at least works (assuming the receiver has the same filesystem layout as you). But that trick does not apply for a bare "-path". - it's meant as an ssh url, like "-host:path". But this already doesn't work, as we explicitly disallow ssh hostnames that begin with a dash (to avoid option injection against ssh). - it's a remote-helper scheme, like "-scheme::data". This _could_ work if the receiver bends over backwards and creates a funny-named helper like "git-remote--scheme". But normally there would not be any helper that matches. Since such a url does not work today and is not likely to do anything useful in the future, let's simply disallow them entirely. That protects the existing "git clone" path (in a belt-and-suspenders way), along with any others that might exist. Our tests cover two cases: 1. A file url with "./" continues to work, showing that there's an escape hatch for people with truly silly repo names. 2. A url starting with "-" is rejected. Note that we expect case (2) to fail, but it would have done so even without this commit, for the reasons given above. So instead of just expecting failure, let's also check for the magic word "ignoring" on stderr. That lets us know that we failed for the right reason. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-24 10:36:30 +02:00
test_expect_success 'remove ./ protection from .gitmodules url' '
perl -i -pe "s{\./}{}" .gitmodules &&
git commit -am "drop protection"
'
test_expect_success 'clone rejects unprotected dash' '
test_when_finished "rm -rf dst" &&
test_must_fail git clone --recurse-submodules . dst 2>err &&
test_i18ngrep ignoring err
'
fsck: detect submodule urls starting with dash Urls with leading dashes can cause mischief on older versions of Git. We should detect them so that they can be rejected by receive.fsckObjects, preventing modern versions of git from being a vector by which attacks can spread. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-24 10:37:17 +02:00
test_expect_success 'fsck rejects unprotected dash' '
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
test_must_fail git push dst HEAD 2>err &&
grep gitmodulesUrl err
'
mingw: fix quoting of arguments We need to be careful to follow proper quoting rules. For example, if an argument contains spaces, we have to quote them. Double-quotes need to be escaped. Backslashes need to be escaped, but only if they are followed by a double-quote character. We need to be _extra_ careful to consider the case where an argument ends in a backslash _and_ needs to be quoted: in this case, we append a double-quote character, i.e. the backslash now has to be escaped! The current code, however, fails to recognize that, and therefore can turn an argument that ends in a single backslash into a quoted argument that now ends in an escaped double-quote character. This allows subsequent command-line parameters to be split and part of them being mistaken for command-line options, e.g. through a maliciously-crafted submodule URL during a recursive clone. Technically, we would not need to quote _all_ arguments which end in a backslash _unless_ the argument needs to be quoted anyway. For example, `test\` would not need to be quoted, while `test \` would need to be. To keep the code simple, however, and therefore easier to reason about and ensure its correctness, we now _always_ quote an argument that ends in a backslash. This addresses CVE-2019-1350. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-09-13 16:32:43 +02:00
test_expect_success 'trailing backslash is handled correctly' '
git init testmodule &&
test_commit -C testmodule c &&
git submodule add ./testmodule &&
: ensure that the name ends in a double backslash &&
sed -e "s|\\(submodule \"testmodule\\)\"|\\1\\\\\\\\\"|" \
-e "s|url = .*|url = \" --should-not-be-an-option\"|" \
<.gitmodules >.new &&
mv .new .gitmodules &&
git commit -am "Add testmodule" &&
test_must_fail git clone --verbose --recurse-submodules . dolly 2>err &&
test_i18ngrep ! "unknown option" err
'
credential: treat URL without scheme as invalid libcurl permits making requests without a URL scheme specified. In this case, it guesses the URL from the hostname, so I can run git ls-remote http::ftp.example.com/path/to/repo and it would make an FTP request. Any user intentionally using such a URL is likely to have made a typo. Unfortunately, credential_from_url is not able to determine the host and protocol in order to determine appropriate credentials to send, and until "credential: refuse to operate when missing host or protocol", this resulted in another host's credentials being leaked to the named host. Teach credential_from_url_gently to consider such a URL to be invalid so that fsck can detect and block gitmodules files with such URLs, allowing server operators to avoid serving them to downstream users running older versions of Git. This also means that when such URLs are passed on the command line, Git will print a clearer error so affected users can switch to the simpler URL that explicitly specifies the host and protocol they intend. One subtlety: .gitmodules files can contain relative URLs, representing a URL relative to the URL they were cloned from. The relative URL resolver used for .gitmodules can follow ".." components out of the path part and past the host part of a URL, meaning that such a relative URL can be used to traverse from a https://foo.example.com/innocent superproject to a https::attacker.example.com/exploit submodule. Fortunately a leading ':' in the first path component after a series of leading './' and '../' components is unlikely to show up in other contexts, so we can catch this by detecting that pattern. Reported-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Jeff King <peff@peff.net>
2020-04-19 05:54:13 +02:00
test_expect_success 'fsck rejects missing URL scheme' '
git checkout --orphan missing-scheme &&
cat >.gitmodules <<-\EOF &&
[submodule "foo"]
url = http::one.example.com/foo.git
EOF
git add .gitmodules &&
test_tick &&
git commit -m "gitmodules with missing URL scheme" &&
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
test_must_fail git push dst HEAD 2>err &&
grep gitmodulesUrl err
'
test_expect_success 'fsck rejects relative URL resolving to missing scheme' '
git checkout --orphan relative-missing-scheme &&
cat >.gitmodules <<-\EOF &&
[submodule "foo"]
url = "..\\../.\\../:one.example.com/foo.git"
EOF
git add .gitmodules &&
test_tick &&
git commit -m "gitmodules with relative URL that strips off scheme" &&
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
test_must_fail git push dst HEAD 2>err &&
grep gitmodulesUrl err
'
credential: treat URL with empty scheme as invalid Until "credential: refuse to operate when missing host or protocol", Git's credential handling code interpreted URLs with empty scheme to mean "give me credentials matching this host for any protocol". Luckily libcurl does not recognize such URLs (it tries to look for a protocol named "" and fails). Just in case that changes, let's reject them within Git as well. This way, credential_from_url is guaranteed to always produce a "struct credential" with protocol and host set. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2020-04-19 05:54:57 +02:00
test_expect_success 'fsck rejects empty URL scheme' '
git checkout --orphan empty-scheme &&
cat >.gitmodules <<-\EOF &&
[submodule "foo"]
url = http::://one.example.com/foo.git
EOF
git add .gitmodules &&
test_tick &&
git commit -m "gitmodules with empty URL scheme" &&
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
test_must_fail git push dst HEAD 2>err &&
grep gitmodulesUrl err
'
test_expect_success 'fsck rejects relative URL resolving to empty scheme' '
git checkout --orphan relative-empty-scheme &&
cat >.gitmodules <<-\EOF &&
[submodule "foo"]
url = ../../../:://one.example.com/foo.git
EOF
git add .gitmodules &&
test_tick &&
git commit -m "relative gitmodules URL resolving to empty scheme" &&
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
test_must_fail git push dst HEAD 2>err &&
grep gitmodulesUrl err
'
fsck: reject URL with empty host in .gitmodules Git's URL parser interprets https:///example.com/repo.git to have no host and a path of "example.com/repo.git". Curl, on the other hand, internally redirects it to https://example.com/repo.git. As a result, until "credential: parse URL without host as empty host, not unset", tricking a user into fetching from such a URL would cause Git to send credentials for another host to example.com. Teach fsck to block and detect .gitmodules files using such a URL to prevent sharing them with Git versions that are not yet protected. A relative URL in a .gitmodules file could also be used to trigger this. The relative URL resolver used for .gitmodules does not normalize sequences of slashes and can follow ".." components out of the path part and to the host part of a URL, meaning that such a relative URL can be used to traverse from a https://foo.example.com/innocent superproject to a https:///attacker.example.com/exploit submodule. Fortunately, redundant extra slashes in .gitmodules are rare, so we can catch this by detecting one after a leading sequence of "./" and "../" components. Helped-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Jeff King <peff@peff.net>
2020-04-19 05:57:22 +02:00
test_expect_success 'fsck rejects empty hostname' '
git checkout --orphan empty-host &&
cat >.gitmodules <<-\EOF &&
[submodule "foo"]
url = http:///one.example.com/foo.git
EOF
git add .gitmodules &&
test_tick &&
git commit -m "gitmodules with extra slashes" &&
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
test_must_fail git push dst HEAD 2>err &&
grep gitmodulesUrl err
'
test_expect_success 'fsck rejects relative url that produced empty hostname' '
git checkout --orphan messy-relative &&
cat >.gitmodules <<-\EOF &&
[submodule "foo"]
url = ../../..//one.example.com/foo.git
EOF
git add .gitmodules &&
test_tick &&
git commit -m "gitmodules abusing relative_path" &&
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
test_must_fail git push dst HEAD 2>err &&
grep gitmodulesUrl err
'
fsck: convert gitmodules url to URL passed to curl In 07259e74ec1 (fsck: detect gitmodules URLs with embedded newlines, 2020-03-11), git fsck learned to check whether URLs in .gitmodules could be understood by the credential machinery when they are handled by git-remote-curl. However, the check is overbroad: it checks all URLs instead of only URLs that would be passed to git-remote-curl. In principle a git:// or file:/// URL does not need to follow the same conventions as an http:// URL; in particular, git:// and file:// protocols are not succeptible to issues in the credential API because they do not support attaching credentials. In the HTTP case, the URL in .gitmodules does not always match the URL that would be passed to git-remote-curl and the credential machinery: Git's URL syntax allows specifying a remote helper followed by a "::" delimiter and a URL to be passed to it, so that git ls-remote http::https://example.com/repo.git invokes git-remote-http with https://example.com/repo.git as its URL argument. With today's checks, that distinction does not make a difference, but for a check we are about to introduce (for empty URL schemes) it will matter. .gitmodules files also support relative URLs. To ensure coverage for the https based embedded-newline attack, urldecode and check them directly for embedded newlines. Helped-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Jeff King <peff@peff.net>
2020-04-19 05:52:34 +02:00
test_expect_success 'fsck permits embedded newline with unrecognized scheme' '
git checkout --orphan newscheme &&
cat >.gitmodules <<-\EOF &&
[submodule "foo"]
url = "data://acjbkd%0akajfdickajkd"
EOF
git add .gitmodules &&
git commit -m "gitmodules with unrecognized scheme" &&
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
git push dst HEAD
'
fsck: detect gitmodules URLs with embedded newlines The credential protocol can't handle values with newlines. We already detect and block any such URLs from being used with credential helpers, but let's also add an fsck check to detect and block gitmodules files with such URLs. That will let us notice the problem earlier when transfer.fsckObjects is turned on. And in particular it will prevent bad objects from spreading, which may protect downstream users running older versions of Git. We'll file this under the existing gitmodulesUrl flag, which covers URLs with option injection. There's really no need to distinguish the exact flaw in the URL in this context. Likewise, I've expanded the description of t7416 to cover all types of bogus URLs.
2020-03-11 23:48:24 +01:00
test_expect_success 'fsck rejects embedded newline in url' '
# create an orphan branch to avoid existing .gitmodules objects
git checkout --orphan newline &&
cat >.gitmodules <<-\EOF &&
[submodule "foo"]
url = "https://one.example.com?%0ahost=two.example.com/foo.git"
EOF
git add .gitmodules &&
git commit -m "gitmodules with newline" &&
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
test_must_fail git push dst HEAD 2>err &&
grep gitmodulesUrl err
'
fsck: convert gitmodules url to URL passed to curl In 07259e74ec1 (fsck: detect gitmodules URLs with embedded newlines, 2020-03-11), git fsck learned to check whether URLs in .gitmodules could be understood by the credential machinery when they are handled by git-remote-curl. However, the check is overbroad: it checks all URLs instead of only URLs that would be passed to git-remote-curl. In principle a git:// or file:/// URL does not need to follow the same conventions as an http:// URL; in particular, git:// and file:// protocols are not succeptible to issues in the credential API because they do not support attaching credentials. In the HTTP case, the URL in .gitmodules does not always match the URL that would be passed to git-remote-curl and the credential machinery: Git's URL syntax allows specifying a remote helper followed by a "::" delimiter and a URL to be passed to it, so that git ls-remote http::https://example.com/repo.git invokes git-remote-http with https://example.com/repo.git as its URL argument. With today's checks, that distinction does not make a difference, but for a check we are about to introduce (for empty URL schemes) it will matter. .gitmodules files also support relative URLs. To ensure coverage for the https based embedded-newline attack, urldecode and check them directly for embedded newlines. Helped-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Jeff King <peff@peff.net>
2020-04-19 05:52:34 +02:00
test_expect_success 'fsck rejects embedded newline in relative url' '
git checkout --orphan relative-newline &&
cat >.gitmodules <<-\EOF &&
[submodule "foo"]
url = "./%0ahost=two.example.com/foo.git"
EOF
git add .gitmodules &&
git commit -m "relative url with newline" &&
test_when_finished "rm -rf dst" &&
git init --bare dst &&
git -C dst config transfer.fsckObjects true &&
test_must_fail git push dst HEAD 2>err &&
grep gitmodulesUrl err
'
submodule-config: ban submodule urls that start with dash The previous commit taught the submodule code to invoke our "git clone $url $path" with a "--" separator so that we aren't confused by urls or paths that start with dashes. However, that's just one code path. It's not clear if there are others, and it would be an easy mistake to add one in the future. Moreover, even with the fix in the previous commit, it's quite hard to actually do anything useful with such an entry. Any url starting with a dash must fall into one of three categories: - it's meant as a file url, like "-path". But then any clone is not going to have the matching path, since it's by definition relative inside the newly created clone. If you spell it as "./-path", the submodule code sees the "/" and translates this to an absolute path, so it at least works (assuming the receiver has the same filesystem layout as you). But that trick does not apply for a bare "-path". - it's meant as an ssh url, like "-host:path". But this already doesn't work, as we explicitly disallow ssh hostnames that begin with a dash (to avoid option injection against ssh). - it's a remote-helper scheme, like "-scheme::data". This _could_ work if the receiver bends over backwards and creates a funny-named helper like "git-remote--scheme". But normally there would not be any helper that matches. Since such a url does not work today and is not likely to do anything useful in the future, let's simply disallow them entirely. That protects the existing "git clone" path (in a belt-and-suspenders way), along with any others that might exist. Our tests cover two cases: 1. A file url with "./" continues to work, showing that there's an escape hatch for people with truly silly repo names. 2. A url starting with "-" is rejected. Note that we expect case (2) to fail, but it would have done so even without this commit, for the reasons given above. So instead of just expecting failure, let's also check for the magic word "ignoring" on stderr. That lets us know that we failed for the right reason. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-24 10:36:30 +02:00
test_done
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