Hi Peff, On Tue, Apr 14, 2020 at 05:43:04PM -0400, Jeff King wrote: > It's unusual to see: > > https://example.com?query-parameters > > without an intervening slash, like: > > https://example.com/some-path?query-parameters > > or even: > > https://example.com/?query-parameters > > but it is a valid end to the hostname (actually "authority component") > according to RFC 3986. Likewise for "#". > > And curl will parse the URL according to the standard, meaning it will > contact example.com, but our credential code would ask about a bogus > hostname with a "?" in it. Let's make sure we follow the standard, and > more importantly ask about the same hosts that curl will be talking to. > > It would be nice if we could just ask curl to parse the URL for us. But > it didn't grow a URL-parsing API until 7.62, so we'd be stuck with > fallback code either way. Plus we'd need this code in the main Git > binary, where we've tried to avoid having a link dependency on libcurl. > > But let's at least fix our parser. Moving to curl's parser would prevent > other potential discrepancies, but this gives us immediate relief for > the known problem, and would help our fallback code if we eventually use > curl. > > Signed-off-by: Jeff King <peff@xxxxxxxx> All makes sense to me. I agree that it would probably be preferable if we could just use cURL's own parser and forget about this code entirely. But, having it still be a fallback knocks out any benefit that we'd be getting by relying on their parser rather than our own. > --- > Just a follow-on to today's release. This isn't security critical after > the earlier fix, but it made some of the attack vectors much easier. Yep, thanks for noting. > credential.c | 9 ++++++++- > t/t0300-credentials.sh | 36 +++++++++++++++++++++++++++++++++++- > 2 files changed, 43 insertions(+), 2 deletions(-) > > diff --git a/credential.c b/credential.c > index 21b3ba152f..8aa9777548 100644 > --- a/credential.c > +++ b/credential.c > @@ -388,7 +388,14 @@ int credential_from_url_gently(struct credential *c, const char *url, > cp = proto_end + 3; > at = strchr(cp, '@'); > colon = strchr(cp, ':'); > - slash = strchrnul(cp, '/'); > + > + /* > + * A query or fragment marker before the slash ends the host portion. > + * We'll just continue to call this "slash" for simplicity. Notably our > + * "trim leading slashes" part won't skip over this part of the path, > + * but that's what we'd want. > + */ > + slash = cp + strcspn(cp, "/?#"); > > if (!at || slash <= at) { > /* Case (1) */ > diff --git a/t/t0300-credentials.sh b/t/t0300-credentials.sh > index 5b78ebbc3f..b6ec676989 100755 > --- a/t/t0300-credentials.sh > +++ b/t/t0300-credentials.sh > @@ -443,11 +443,45 @@ test_expect_success 'url parser ignores embedded newlines' ' > username=askpass-username > password=askpass-password > -- > - warning: url contains a newline in its host component: https://one.example.com?%0ahost=two.example.com/ > + warning: url contains a newline in its path component: https://one.example.com?%0ahost=two.example.com/ > warning: skipping credential lookup for url: https://one.example.com?%0ahost=two.example.com/ > askpass: Username: > askpass: Password: > EOF > ' > > +# usage: check_host_and_path <url> <expected-host> <expected-path> > +check_host_and_path () { > + # we always parse the path component, but we need this to make sure it > + # is passed to the helper > + test_config credential.useHTTPPath true && > + check fill "verbatim user pass" <<-EOF > + url=$1 > + -- > + protocol=https > + host=$2 > + path=$3 > + username=user > + password=pass > + -- > + verbatim: get > + verbatim: protocol=https > + verbatim: host=$2 > + verbatim: path=$3 > + EOF > +} > + > +test_expect_success 'url parser handles bare query marker' ' > + check_host_and_path https://example.com?foo.git example.com ?foo.git > +' > + > +test_expect_success 'url parser handles bare fragment marker' ' > + check_host_and_path https://example.com#foo.git example.com "#foo.git" > +' > + > +test_expect_success 'url parser not confused by encoded markers' ' > + check_host_and_path https://example.com%23%3f%2f/foo.git \ > + "example.com#?/" foo.git > +' > + > test_done These look good, too. Thanks for working on this. > -- > 2.26.1.429.g609150846d Thanks, Taylor
