Files
git/t/lib-httpd/apache.conf
Jeff King 6628eb41db http: always update the base URL for redirects
If a malicious server redirects the initial ref
advertisement, it may be able to leak sha1s from other,
unrelated servers that the client has access to. For
example, imagine that Alice is a git user, she has access to
a private repository on a server hosted by Bob, and Mallory
runs a malicious server and wants to find out about Bob's
private repository.

Mallory asks Alice to clone an unrelated repository from her
over HTTP. When Alice's client contacts Mallory's server for
the initial ref advertisement, the server issues an HTTP
redirect for Bob's server. Alice contacts Bob's server and
gets the ref advertisement for the private repository. If
there is anything to fetch, she then follows up by asking
the server for one or more sha1 objects. But who is the
server?

If it is still Mallory's server, then Alice will leak the
existence of those sha1s to her.

Since commit c93c92f30 (http: update base URLs when we see
redirects, 2013-09-28), the client usually rewrites the base
URL such that all further requests will go to Bob's server.
But this is done by textually matching the URL. If we were
originally looking for "http://mallory/repo.git/info/refs",
and we got pointed at "http://bob/other.git/info/refs", then
we know that the right root is "http://bob/other.git".

If the redirect appears to change more than just the root,
we punt and continue to use the original server. E.g.,
imagine the redirect adds a URL component that Bob's server
will ignore, like "http://bob/other.git/info/refs?dummy=1".

We can solve this by aborting in this case rather than
silently continuing to use Mallory's server. In addition to
protecting from sha1 leakage, it's arguably safer and more
sane to refuse a confusing redirect like that in general.
For example, part of the motivation in c93c92f30 is
avoiding accidentally sending credentials over clear http,
just to get a response that says "try again over https". So
even in a non-malicious case, we'd prefer to err on the side
of caution.

The downside is that it's possible this will break a
legitimate but complicated server-side redirection scheme.
The setup given in the newly added test does work, but it's
convoluted enough that we don't need to care about it. A
more plausible case would be a server which redirects a
request for "info/refs?service=git-upload-pack" to just
"info/refs" (because it does not do smart HTTP, and for some
reason really dislikes query parameters).  Right now we
would transparently downgrade to dumb-http, but with this
patch, we'd complain (and the user would have to set
GIT_SMART_HTTP=0 to fetch).

Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-06 12:32:48 -08:00

224 lines
5.9 KiB
ApacheConf

ServerName dummy
PidFile httpd.pid
DocumentRoot www
LogFormat "%h %l %u %t \"%r\" %>s %b" common
CustomLog access.log common
ErrorLog error.log
<IfModule !mod_log_config.c>
LoadModule log_config_module modules/mod_log_config.so
</IfModule>
<IfModule !mod_alias.c>
LoadModule alias_module modules/mod_alias.so
</IfModule>
<IfModule !mod_cgi.c>
LoadModule cgi_module modules/mod_cgi.so
</IfModule>
<IfModule !mod_env.c>
LoadModule env_module modules/mod_env.so
</IfModule>
<IfModule !mod_rewrite.c>
LoadModule rewrite_module modules/mod_rewrite.so
</IFModule>
<IfModule !mod_version.c>
LoadModule version_module modules/mod_version.so
</IfModule>
<IfModule !mod_headers.c>
LoadModule headers_module modules/mod_headers.so
</IfModule>
<IfVersion < 2.4>
LockFile accept.lock
</IfVersion>
<IfVersion < 2.1>
<IfModule !mod_auth.c>
LoadModule auth_module modules/mod_auth.so
</IfModule>
</IfVersion>
<IfVersion >= 2.1>
<IfModule !mod_auth_basic.c>
LoadModule auth_basic_module modules/mod_auth_basic.so
</IfModule>
<IfModule !mod_authn_file.c>
LoadModule authn_file_module modules/mod_authn_file.so
</IfModule>
<IfModule !mod_authz_user.c>
LoadModule authz_user_module modules/mod_authz_user.so
</IfModule>
<IfModule !mod_authz_host.c>
LoadModule authz_host_module modules/mod_authz_host.so
</IfModule>
</IfVersion>
<IfVersion >= 2.4>
<IfModule !mod_authn_core.c>
LoadModule authn_core_module modules/mod_authn_core.so
</IfModule>
<IfModule !mod_authz_core.c>
LoadModule authz_core_module modules/mod_authz_core.so
</IfModule>
<IfModule !mod_access_compat.c>
LoadModule access_compat_module modules/mod_access_compat.so
</IfModule>
<IfModule !mod_mpm_prefork.c>
LoadModule mpm_prefork_module modules/mod_mpm_prefork.so
</IfModule>
<IfModule !mod_unixd.c>
LoadModule unixd_module modules/mod_unixd.so
</IfModule>
</IfVersion>
PassEnv GIT_VALGRIND
PassEnv GIT_VALGRIND_OPTIONS
PassEnv GNUPGHOME
PassEnv ASAN_OPTIONS
PassEnv GIT_TRACE
PassEnv GIT_CONFIG_NOSYSTEM
Alias /dumb/ www/
Alias /auth/dumb/ www/auth/dumb/
<LocationMatch /smart/>
SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
SetEnv GIT_HTTP_EXPORT_ALL
</LocationMatch>
<LocationMatch /smart_noexport/>
SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
</LocationMatch>
<LocationMatch /smart_custom_env/>
SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
SetEnv GIT_HTTP_EXPORT_ALL
SetEnv GIT_COMMITTER_NAME "Custom User"
SetEnv GIT_COMMITTER_EMAIL custom@example.com
</LocationMatch>
<LocationMatch /smart_namespace/>
SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
SetEnv GIT_HTTP_EXPORT_ALL
SetEnv GIT_NAMESPACE ns
</LocationMatch>
<LocationMatch /smart_cookies/>
SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
SetEnv GIT_HTTP_EXPORT_ALL
Header set Set-Cookie name=value
</LocationMatch>
<LocationMatch /smart_headers/>
SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
SetEnv GIT_HTTP_EXPORT_ALL
</LocationMatch>
ScriptAliasMatch /smart_*[^/]*/(.*) ${GIT_EXEC_PATH}/git-http-backend/$1
ScriptAlias /broken_smart/ broken-smart-http.sh/
ScriptAlias /error/ error.sh/
<Directory ${GIT_EXEC_PATH}>
Options FollowSymlinks
</Directory>
<Files broken-smart-http.sh>
Options ExecCGI
</Files>
<Files error.sh>
Options ExecCGI
</Files>
<Files ${GIT_EXEC_PATH}/git-http-backend>
Options ExecCGI
</Files>
RewriteEngine on
RewriteRule ^/smart-redir-perm/(.*)$ /smart/$1 [R=301]
RewriteRule ^/smart-redir-temp/(.*)$ /smart/$1 [R=302]
RewriteRule ^/smart-redir-auth/(.*)$ /auth/smart/$1 [R=301]
RewriteRule ^/smart-redir-limited/(.*)/info/refs$ /smart/$1/info/refs [R=301]
RewriteRule ^/ftp-redir/(.*)$ ftp://localhost:1000/$1 [R=302]
RewriteRule ^/loop-redir/x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-(.*) /$1 [R=302]
RewriteRule ^/loop-redir/(.*)$ /loop-redir/x-$1 [R=302]
# The first rule issues a client-side redirect to something
# that _doesn't_ look like a git repo. The second rule is a
# server-side rewrite, so that it turns out the odd-looking
# thing _is_ a git repo. The "[PT]" tells Apache to match
# the usual ScriptAlias rules for /smart.
RewriteRule ^/insane-redir/(.*)$ /intern-redir/$1/foo [R=301]
RewriteRule ^/intern-redir/(.*)/foo$ /smart/$1 [PT]
# Apache 2.2 does not understand <RequireAll>, so we use RewriteCond.
# And as RewriteCond does not allow testing for non-matches, we match
# the desired case first (one has abra, two has cadabra), and let it
# pass by marking the RewriteRule as [L], "last rule, do not process
# any other matching RewriteRules after this"), and then have another
# RewriteRule that matches all other cases and lets them fail via '[F]',
# "fail the request".
RewriteCond %{HTTP:x-magic-one} =abra
RewriteCond %{HTTP:x-magic-two} =cadabra
RewriteRule ^/smart_headers/.* - [L]
RewriteRule ^/smart_headers/.* - [F]
<IfDefine SSL>
LoadModule ssl_module modules/mod_ssl.so
SSLCertificateFile httpd.pem
SSLCertificateKeyFile httpd.pem
SSLRandomSeed startup file:/dev/urandom 512
SSLRandomSeed connect file:/dev/urandom 512
SSLSessionCache none
SSLMutex file:ssl_mutex
SSLEngine On
</IfDefine>
<Location /auth/>
AuthType Basic
AuthName "git-auth"
AuthUserFile passwd
Require valid-user
</Location>
<LocationMatch "^/auth-push/.*/git-receive-pack$">
AuthType Basic
AuthName "git-auth"
AuthUserFile passwd
Require valid-user
</LocationMatch>
<LocationMatch "^/auth-fetch/.*/git-upload-pack$">
AuthType Basic
AuthName "git-auth"
AuthUserFile passwd
Require valid-user
</LocationMatch>
RewriteCond %{QUERY_STRING} service=git-receive-pack [OR]
RewriteCond %{REQUEST_URI} /git-receive-pack$
RewriteRule ^/half-auth-complete/ - [E=AUTHREQUIRED:yes]
<Location /half-auth-complete/>
Order Deny,Allow
Deny from env=AUTHREQUIRED
AuthType Basic
AuthName "Git Access"
AuthUserFile passwd
Require valid-user
Satisfy Any
</Location>
<IfDefine DAV>
LoadModule dav_module modules/mod_dav.so
LoadModule dav_fs_module modules/mod_dav_fs.so
DAVLockDB DAVLock
<Location /dumb/>
Dav on
</Location>
<Location /auth/dumb>
Dav on
</Location>
</IfDefine>
<IfDefine SVN>
LoadModule dav_svn_module modules/mod_dav_svn.so
<Location /svn>
DAV svn
SVNPath svnrepo
</Location>
</IfDefine>