diff options
| -rw-r--r-- | Documentation/git.txt | 32 | ||||
| -rw-r--r-- | connect.c | 5 | ||||
| -rwxr-xr-x | git-submodule.sh | 9 | ||||
| -rw-r--r-- | t/lib-proto-disable.sh | 96 | ||||
| -rwxr-xr-x | t/t5810-proto-disable-local.sh | 14 | ||||
| -rwxr-xr-x | t/t5811-proto-disable-git.sh | 20 | ||||
| -rwxr-xr-x | t/t5812-proto-disable-http.sh | 20 | ||||
| -rwxr-xr-x | t/t5813-proto-disable-ssh.sh | 20 | ||||
| -rwxr-xr-x | t/t5814-proto-disable-ext.sh | 18 | ||||
| -rwxr-xr-x | t/t5815-submodule-protos.sh | 43 | ||||
| -rw-r--r-- | transport-helper.c | 2 | ||||
| -rw-r--r-- | transport.c | 21 | ||||
| -rw-r--r-- | transport.h | 7 |
13 files changed, 306 insertions, 1 deletions
diff --git a/Documentation/git.txt b/Documentation/git.txt index a62ed6f..b6a12b3 100644 --- a/Documentation/git.txt +++ b/Documentation/git.txt @@ -1045,6 +1045,38 @@ GIT_ICASE_PATHSPECS:: an operation has touched every ref (e.g., because you are cloning a repository to make a backup). +`GIT_ALLOW_PROTOCOL`:: + If set, provide a colon-separated list of protocols which are + allowed to be used with fetch/push/clone. This is useful to + restrict recursive submodule initialization from an untrusted + repository. Any protocol not mentioned will be disallowed (i.e., + this is a whitelist, not a blacklist). If the variable is not + set at all, all protocols are enabled. The protocol names + currently used by git are: + + - `file`: any local file-based path (including `file://` URLs, + or local paths) + + - `git`: the anonymous git protocol over a direct TCP + connection (or proxy, if configured) + + - `ssh`: git over ssh (including `host:path` syntax, + `git+ssh://`, etc). + + - `rsync`: git over rsync + + - `http`: git over http, both "smart http" and "dumb http". + Note that this does _not_ include `https`; if you want both, + you should specify both as `http:https`. + + - any external helpers are named by their protocol (e.g., use + `hg` to allow the `git-remote-hg` helper) ++ +Note that this controls only git's internal protocol selection. +If libcurl is used (e.g., by the `http` transport), it may +redirect to other protocols. There is not currently any way to +restrict this. + Discussion[[Discussion]] ------------------------ @@ -9,6 +9,7 @@ #include "url.h" #include "string-list.h" #include "sha1-array.h" +#include "transport.h" static char *server_capabilities; static const char *parse_feature_value(const char *, const char *, int *); @@ -694,6 +695,8 @@ struct child_process *git_connect(int fd[2], const char *url, else target_host = xstrdup(hostandport); + transport_check_allowed("git"); + /* These underlying connection commands die() if they * cannot connect. */ @@ -727,6 +730,7 @@ struct child_process *git_connect(int fd[2], const char *url, int putty; char *ssh_host = hostandport; const char *port = NULL; + transport_check_allowed("ssh"); get_host_and_port(&ssh_host, &port); if (!port) @@ -768,6 +772,7 @@ struct child_process *git_connect(int fd[2], const char *url, /* remove repo-local variables from the environment */ conn->env = local_repo_env; conn->use_shell = 1; + transport_check_allowed("file"); } argv_array_push(&conn->args, cmd.buf); diff --git a/git-submodule.sh b/git-submodule.sh index 36797c3..78c2740 100755 --- a/git-submodule.sh +++ b/git-submodule.sh @@ -22,6 +22,15 @@ require_work_tree wt_prefix=$(git rev-parse --show-prefix) cd_to_toplevel +# Restrict ourselves to a vanilla subset of protocols; the URLs +# we get are under control of a remote repository, and we do not +# want them kicking off arbitrary git-remote-* programs. +# +# If the user has already specified a set of allowed protocols, +# we assume they know what they're doing and use that instead. +: ${GIT_ALLOW_PROTOCOL=file:git:http:https:ssh} +export GIT_ALLOW_PROTOCOL + command= branch= force= diff --git a/t/lib-proto-disable.sh b/t/lib-proto-disable.sh new file mode 100644 index 0000000..b0917d9 --- /dev/null +++ b/t/lib-proto-disable.sh @@ -0,0 +1,96 @@ +# Test routines for checking protocol disabling. + +# test cloning a particular protocol +# $1 - description of the protocol +# $2 - machine-readable name of the protocol +# $3 - the URL to try cloning +test_proto () { + desc=$1 + proto=$2 + url=$3 + + test_expect_success "clone $1 (enabled)" ' + rm -rf tmp.git && + ( + GIT_ALLOW_PROTOCOL=$proto && + export GIT_ALLOW_PROTOCOL && + git clone --bare "$url" tmp.git + ) + ' + + test_expect_success "fetch $1 (enabled)" ' + ( + cd tmp.git && + GIT_ALLOW_PROTOCOL=$proto && + export GIT_ALLOW_PROTOCOL && + git fetch + ) + ' + + test_expect_success "push $1 (enabled)" ' + ( + cd tmp.git && + GIT_ALLOW_PROTOCOL=$proto && + export GIT_ALLOW_PROTOCOL && + git push origin HEAD:pushed + ) + ' + + test_expect_success "push $1 (disabled)" ' + ( + cd tmp.git && + GIT_ALLOW_PROTOCOL=none && + export GIT_ALLOW_PROTOCOL && + test_must_fail git push origin HEAD:pushed + ) + ' + + test_expect_success "fetch $1 (disabled)" ' + ( + cd tmp.git && + GIT_ALLOW_PROTOCOL=none && + export GIT_ALLOW_PROTOCOL && + test_must_fail git fetch + ) + ' + + test_expect_success "clone $1 (disabled)" ' + rm -rf tmp.git && + ( + GIT_ALLOW_PROTOCOL=none && + export GIT_ALLOW_PROTOCOL && + test_must_fail git clone --bare "$url" tmp.git + ) + ' +} + +# set up an ssh wrapper that will access $host/$repo in the +# trash directory, and enable it for subsequent tests. +setup_ssh_wrapper () { + test_expect_success 'setup ssh wrapper' ' + write_script ssh-wrapper <<-\EOF && + echo >&2 "ssh: $*" + host=$1; shift + cd "$TRASH_DIRECTORY/$host" && + eval "$*" + EOF + GIT_SSH="$PWD/ssh-wrapper" && + export GIT_SSH && + export TRASH_DIRECTORY + ' +} + +# set up a wrapper that can be used with remote-ext to +# access repositories in the "remote" directory of trash-dir, +# like "ext::fake-remote %S repo.git" +setup_ext_wrapper () { + test_expect_success 'setup ext wrapper' ' + write_script fake-remote <<-\EOF && + echo >&2 "fake-remote: $*" + cd "$TRASH_DIRECTORY/remote" && + eval "$*" + EOF + PATH=$TRASH_DIRECTORY:$PATH && + export TRASH_DIRECTORY + ' +} diff --git a/t/t5810-proto-disable-local.sh b/t/t5810-proto-disable-local.sh new file mode 100755 index 0000000..563592d --- /dev/null +++ b/t/t5810-proto-disable-local.sh @@ -0,0 +1,14 @@ +#!/bin/sh + +test_description='test disabling of local paths in clone/fetch' +. ./test-lib.sh +. "$TEST_DIRECTORY/lib-proto-disable.sh" + +test_expect_success 'setup repository to clone' ' + test_commit one +' + +test_proto "file://" file "file://$PWD" +test_proto "path" file . + +test_done diff --git a/t/t5811-proto-disable-git.sh b/t/t5811-proto-disable-git.sh new file mode 100755 index 0000000..8ac6b2a --- /dev/null +++ b/t/t5811-proto-disable-git.sh @@ -0,0 +1,20 @@ +#!/bin/sh + +test_description='test disabling of git-over-tcp in clone/fetch' +. ./test-lib.sh +. "$TEST_DIRECTORY/lib-proto-disable.sh" +. "$TEST_DIRECTORY/lib-git-daemon.sh" +start_git_daemon + +test_expect_success 'create git-accessible repo' ' + bare="$GIT_DAEMON_DOCUMENT_ROOT_PATH/repo.git" && + test_commit one && + git --bare init "$bare" && + git push "$bare" HEAD && + >"$bare/git-daemon-export-ok" && + git -C "$bare" config daemon.receivepack true +' + +test_proto "git://" git "$GIT_DAEMON_URL/repo.git" + +test_done diff --git a/t/t5812-proto-disable-http.sh b/t/t5812-proto-disable-http.sh new file mode 100755 index 0000000..dd5001c --- /dev/null +++ b/t/t5812-proto-disable-http.sh @@ -0,0 +1,20 @@ +#!/bin/sh + +test_description='test disabling of git-over-http in clone/fetch' +. ./test-lib.sh +. "$TEST_DIRECTORY/lib-proto-disable.sh" +. "$TEST_DIRECTORY/lib-httpd.sh" +start_httpd + +test_expect_success 'create git-accessible repo' ' + bare="$HTTPD_DOCUMENT_ROOT_PATH/repo.git" && + test_commit one && + git --bare init "$bare" && + git push "$bare" HEAD && + git -C "$bare" config http.receivepack true +' + +test_proto "smart http" http "$HTTPD_URL/smart/repo.git" + +stop_httpd +test_done diff --git a/t/t5813-proto-disable-ssh.sh b/t/t5813-proto-disable-ssh.sh new file mode 100755 index 0000000..ad877d7 --- /dev/null +++ b/t/t5813-proto-disable-ssh.sh @@ -0,0 +1,20 @@ +#!/bin/sh + +test_description='test disabling of git-over-ssh in clone/fetch' +. ./test-lib.sh +. "$TEST_DIRECTORY/lib-proto-disable.sh" + +setup_ssh_wrapper + +test_expect_success 'setup repository to clone' ' + test_commit one && + mkdir remote && + git init --bare remote/repo.git && + git push remote/repo.git HEAD +' + +test_proto "host:path" ssh "remote:repo.git" +test_proto "ssh://" ssh "ssh://remote/$PWD/remote/repo.git" +test_proto "git+ssh://" ssh "git+ssh://remote/$PWD/remote/repo.git" + +test_done diff --git a/t/t5814-proto-disable-ext.sh b/t/t5814-proto-disable-ext.sh new file mode 100755 index 0000000..9d6f7df --- /dev/null +++ b/t/t5814-proto-disable-ext.sh @@ -0,0 +1,18 @@ +#!/bin/sh + +test_description='test disabling of remote-helper paths in clone/fetch' +. ./test-lib.sh +. "$TEST_DIRECTORY/lib-proto-disable.sh" + +setup_ext_wrapper + +test_expect_success 'setup repository to clone' ' + test_commit one && + mkdir remote && + git init --bare remote/repo.git && + git push remote/repo.git HEAD +' + +test_proto "remote-helper" ext "ext::fake-remote %S repo.git" + +test_done diff --git a/t/t5815-submodule-protos.sh b/t/t5815-submodule-protos.sh new file mode 100755 index 0000000..06f55a1 --- /dev/null +++ b/t/t5815-submodule-protos.sh @@ -0,0 +1,43 @@ +#!/bin/sh + +test_description='test protocol whitelisting with submodules' +. ./test-lib.sh +. "$TEST_DIRECTORY"/lib-proto-disable.sh + +setup_ext_wrapper +setup_ssh_wrapper + +test_expect_success 'setup repository with submodules' ' + mkdir remote && + git init remote/repo.git && + (cd remote/repo.git && test_commit one) && + # submodule-add should probably trust what we feed it on the cmdline, + # but its implementation is overly conservative. + GIT_ALLOW_PROTOCOL=ssh git submodule add remote:repo.git ssh-module && + GIT_ALLOW_PROTOCOL=ext git submodule add "ext::fake-remote %S repo.git" ext-module && + git commit -m "add submodules" +' + +test_expect_success 'clone with recurse-submodules fails' ' + test_must_fail git clone --recurse-submodules . dst +' + +test_expect_success 'setup individual updates' ' + rm -rf dst && + git clone . dst && + git -C dst submodule init +' + +test_expect_success 'update of ssh allowed' ' + git -C dst submodule update ssh-module +' + +test_expect_success 'update of ext not allowed' ' + test_must_fail git -C dst submodule update ext-module +' + +test_expect_success 'user can override whitelist' ' + GIT_ALLOW_PROTOCOL=ext git -C dst submodule update ext-module +' + +test_done diff --git a/transport-helper.c b/transport-helper.c index 7dc4a44..0b5362c 100644 --- a/transport-helper.c +++ b/transport-helper.c @@ -1038,6 +1038,8 @@ int transport_helper_init(struct transport *transport, const char *name) struct helper_data *data = xcalloc(1, sizeof(*data)); data->name = name; + transport_check_allowed(name); + if (getenv("GIT_TRANSPORT_HELPER_DEBUG")) debug = 1; diff --git a/transport.c b/transport.c index 88bde1d..94fe865 100644 --- a/transport.c +++ b/transport.c @@ -909,6 +909,20 @@ static int external_specification_len(const char *url) return strchr(url, ':') - url; } +void transport_check_allowed(const char *type) +{ + struct string_list allowed = STRING_LIST_INIT_DUP; + const char *v = getenv("GIT_ALLOW_PROTOCOL"); + + if (!v) + return; + + string_list_split(&allowed, v, ':', -1); + if (!unsorted_string_list_has_string(&allowed, type)) + die("transport '%s' not allowed", type); + string_list_clear(&allowed, 0); +} + struct transport *transport_get(struct remote *remote, const char *url) { const char *helper; @@ -940,12 +954,14 @@ struct transport *transport_get(struct remote *remote, const char *url) if (helper) { transport_helper_init(ret, helper); } else if (starts_with(url, "rsync:")) { + transport_check_allowed("rsync"); ret->get_refs_list = get_refs_via_rsync; ret->fetch = fetch_objs_via_rsync; ret->push = rsync_transport_push; ret->smart_options = NULL; } else if (url_is_local_not_ssh(url) && is_file(url) && is_bundle(url, 1)) { struct bundle_transport_data *data = xcalloc(1, sizeof(*data)); + transport_check_allowed("file"); ret->data = data; ret->get_refs_list = get_refs_from_bundle; ret->fetch = fetch_refs_from_bundle; @@ -957,7 +973,10 @@ struct transport *transport_get(struct remote *remote, const char *url) || starts_with(url, "ssh://") || starts_with(url, "git+ssh://") || starts_with(url, "ssh+git://")) { - /* These are builtin smart transports. */ + /* + * These are builtin smart transports; "allowed" transports + * will be checked individually in git_connect. + */ struct git_transport_data *data = xcalloc(1, sizeof(*data)); ret->data = data; ret->set_option = NULL; diff --git a/transport.h b/transport.h index 3e0091e..f7df6ec 100644 --- a/transport.h +++ b/transport.h @@ -132,6 +132,13 @@ struct transport { /* Returns a transport suitable for the url */ struct transport *transport_get(struct remote *, const char *); +/* + * Check whether a transport is allowed by the environment, + * and die otherwise. type should generally be the URL scheme, + * as described in Documentation/git.txt + */ +void transport_check_allowed(const char *type); + /* Transport options which apply to git:// and scp-style URLs */ /* The program to use on the remote side to send a pack */ |