From 85e42053658cf6710b84974be0ef0acf459a80d9 Mon Sep 17 00:00:00 2001
From: Brandon Williams <bmwill@google.com>
Date: Wed, 14 Dec 2016 14:39:50 -0800
Subject: [PATCH 1/6] lib-proto-disable: variable name fix
The test_proto function assigns the positional parameters to named
variables, but then still refers to "$desc" as "$1". Using $desc is
more readable and less error-prone.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
t/lib-proto-disable.sh | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/t/lib-proto-disable.sh b/t/lib-proto-disable.sh
index b0917d93e64..be88e9a00f5 100644
--- a/t/lib-proto-disable.sh
+++ b/t/lib-proto-disable.sh
@@ -9,7 +9,7 @@ test_proto () {
proto=$2
url=$3
- test_expect_success "clone $1 (enabled)" '
+ test_expect_success "clone $desc (enabled)" '
rm -rf tmp.git &&
(
GIT_ALLOW_PROTOCOL=$proto &&
@@ -18,7 +18,7 @@ test_proto () {
)
'
- test_expect_success "fetch $1 (enabled)" '
+ test_expect_success "fetch $desc (enabled)" '
(
cd tmp.git &&
GIT_ALLOW_PROTOCOL=$proto &&
@@ -27,7 +27,7 @@ test_proto () {
)
'
- test_expect_success "push $1 (enabled)" '
+ test_expect_success "push $desc (enabled)" '
(
cd tmp.git &&
GIT_ALLOW_PROTOCOL=$proto &&
@@ -36,7 +36,7 @@ test_proto () {
)
'
- test_expect_success "push $1 (disabled)" '
+ test_expect_success "push $desc (disabled)" '
(
cd tmp.git &&
GIT_ALLOW_PROTOCOL=none &&
@@ -45,7 +45,7 @@ test_proto () {
)
'
- test_expect_success "fetch $1 (disabled)" '
+ test_expect_success "fetch $desc (disabled)" '
(
cd tmp.git &&
GIT_ALLOW_PROTOCOL=none &&
@@ -54,7 +54,7 @@ test_proto () {
)
'
- test_expect_success "clone $1 (disabled)" '
+ test_expect_success "clone $desc (disabled)" '
rm -rf tmp.git &&
(
GIT_ALLOW_PROTOCOL=none &&
From f962ddf6edb199b2611d575a75f60d20d5c137c3 Mon Sep 17 00:00:00 2001
From: Brandon Williams <bmwill@google.com>
Date: Wed, 14 Dec 2016 14:39:51 -0800
Subject: [PATCH 2/6] http: always warn if libcurl version is too old
Always warn if libcurl version is too old because:
1. Even without a protocol whitelist, newer versions of curl have all
non-standard protocols disabled by default.
2. A future patch will introduce default "known-good" and "known-bad"
protocols which are allowed/disallowed by 'is_transport_allowed'
which older version of libcurl can't respect.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
http.c | 5 ++---
transport.c | 5 -----
transport.h | 6 ------
3 files changed, 2 insertions(+), 14 deletions(-)
diff --git a/http.c b/http.c
index 5cd3ffd67f4..034426e746f 100644
--- a/http.c
+++ b/http.c
@@ -583,9 +583,8 @@ static CURL *get_curl_handle(void)
curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS, allowed_protocols);
curl_easy_setopt(result, CURLOPT_PROTOCOLS, allowed_protocols);
#else
- if (transport_restrict_protocols())
- warning("protocol restrictions not applied to curl redirects because\n"
- "your curl version is too old (>= 7.19.4)");
+ warning("protocol restrictions not applied to curl redirects because\n"
+ "your curl version is too old (>= 7.19.4)");
#endif
if (getenv("GIT_CURL_VERBOSE"))
diff --git a/transport.c b/transport.c
index 41eb82c6f3f..dff929ec01f 100644
--- a/transport.c
+++ b/transport.c
@@ -629,11 +629,6 @@ void transport_check_allowed(const char *type)
die("transport '%s' not allowed", type);
}
-int transport_restrict_protocols(void)
-{
- return !!protocol_whitelist();
-}
-
struct transport *transport_get(struct remote *remote, const char *url)
{
const char *helper;
diff --git a/transport.h b/transport.h
index c68140892c6..3396e1d4340 100644
--- a/transport.h
+++ b/transport.h
@@ -153,12 +153,6 @@ int is_transport_allowed(const char *type);
*/
void transport_check_allowed(const char *type);
-/*
- * Returns true if the user has attempted to turn on protocol
- * restrictions at all.
- */
-int transport_restrict_protocols(void);
-
/* Transport options which apply to git:// and scp-style URLs */
/* The program to use on the remote side to send a pack */
From f1762d772e9b415a3163abf5f217fc3b71a3b40e Mon Sep 17 00:00:00 2001
From: Brandon Williams <bmwill@google.com>
Date: Wed, 14 Dec 2016 14:39:52 -0800
Subject: [PATCH 3/6] transport: add protocol policy config option
Previously the `GIT_ALLOW_PROTOCOL` environment variable was used to
specify a whitelist of protocols to be used in clone/fetch/push
commands. This patch introduces new configuration options for more
fine-grained control for allowing/disallowing protocols. This also has
the added benefit of allowing easier construction of a protocol
whitelist on systems where setting an environment variable is
non-trivial.
Now users can specify a policy to be used for each type of protocol via
the 'protocol.<name>.allow' config option. A default policy for all
unconfigured protocols can be set with the 'protocol.allow' config
option. If no user configured default is made git will allow known-safe
protocols (http, https, git, ssh, file), disallow known-dangerous
protocols (ext), and have a default policy of `user` for all other
protocols.
The supported policies are `always`, `never`, and `user`. The `user`
policy can be used to configure a protocol to be usable when explicitly
used by a user, while disallowing it for commands which run
clone/fetch/push commands without direct user intervention (e.g.
recursive initialization of submodules). Commands which can potentially
clone/fetch/push from untrusted repositories without user intervention
can export `GIT_PROTOCOL_FROM_USER` with a value of '0' to prevent
protocols configured to the `user` policy from being used.
Fix remote-ext tests to use the new config to allow the ext
protocol to be tested.
Based on a patch by Jeff King <peff@peff.net>
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
Documentation/config.txt | 46 +++++++++++
Documentation/git.txt | 36 ++++-----
git-submodule.sh | 12 +--
t/lib-proto-disable.sh | 130 +++++++++++++++++++++++++++++--
t/t5509-fetch-push-namespaces.sh | 1 +
t/t5802-connect-helper.sh | 1 +
transport.c | 75 +++++++++++++++++-
7 files changed, 263 insertions(+), 38 deletions(-)
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 81533364352..50d3d06ffa0 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -2260,6 +2260,52 @@ pretty.<name>::
Note that an alias with the same name as a built-in format
will be silently ignored.
+protocol.allow::
+ If set, provide a user defined default policy for all protocols which
+ don't explicitly have a policy (`protocol.<name>.allow`). By default,
+ if unset, known-safe protocols (http, https, git, ssh, file) have a
+ default policy of `always`, known-dangerous protocols (ext) have a
+ default policy of `never`, and all other protocols have a default
+ policy of `user`. Supported policies:
++
+--
+
+* `always` - protocol is always able to be used.
+
+* `never` - protocol is never able to be used.
+
+* `user` - protocol is only able to be used when `GIT_PROTOCOL_FROM_USER` is
+ either unset or has a value of 1. This policy should be used when you want a
+ protocol to be directly usable by the user but don't want it used by commands which
+ execute clone/fetch/push commands without user input, e.g. recursive
+ submodule initialization.
+
+--
+
+protocol.<name>.allow::
+ Set a policy to be used by protocol `<name>` with clone/fetch/push
+ commands. See `protocol.allow` above for the available policies.
++
+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,
+ `ssh://`, etc).
+
+ - `http`: git over http, both "smart http" and "dumb http".
+ Note that this does _not_ include `https`; if you want to configure
+ both, you must do so individually.
+
+ - any external helpers are named by their protocol (e.g., use
+ `hg` to allow the `git-remote-hg` helper)
+--
+
pull.ff::
By default, Git does not create an extra merge commit when merging
a commit that is a descendant of the current commit. Instead, the
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 923aa49db7f..d9fb937586c 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -1129,30 +1129,20 @@ of clones and fetches.
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,
- `ssh://`, etc).
-
- - `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)
+ If set to a colon-separated list of protocols, behave as if
+ `protocol.allow` is set to `never`, and each of the listed
+ protocols has `protocol.<name>.allow` set to `always`
+ (overriding any existing configuration). In other words, any
+ protocol not mentioned will be disallowed (i.e., this is a
+ whitelist, not a blacklist). See the description of
+ `protocol.allow` in linkgit:git-config[1] for more details.
+`GIT_PROTOCOL_FROM_USER`::
+ Set to 0 to prevent protocols used by fetch/push/clone which are
+ configured to the `user` state. This is useful to restrict recursive
+ submodule initialization from an untrusted repository or for programs
+ which feed potentially-untrusted URLS to git commands. See
+ linkgit:git-config[1] for more details.
Discussion[[Discussion]]
------------------------
diff --git a/git-submodule.sh b/git-submodule.sh
index 78fdac95684..fc440761af9 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -22,14 +22,10 @@ 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
+# Tell the rest of git that any URLs we get don't come
+# directly from the user, so it can apply policy as appropriate.
+GIT_PROTOCOL_FROM_USER=0
+export GIT_PROTOCOL_FROM_USER
command=
branch=
diff --git a/t/lib-proto-disable.sh b/t/lib-proto-disable.sh
index be88e9a00f5..02f49cb4097 100644
--- a/t/lib-proto-disable.sh
+++ b/t/lib-proto-disable.sh
@@ -1,10 +1,7 @@
# 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 () {
+# Test clone/fetch/push with GIT_ALLOW_PROTOCOL whitelist
+test_whitelist () {
desc=$1
proto=$2
url=$3
@@ -62,6 +59,129 @@ test_proto () {
test_must_fail git clone --bare "$url" tmp.git
)
'
+
+ test_expect_success "clone $desc (env var has precedence)" '
+ rm -rf tmp.git &&
+ (
+ GIT_ALLOW_PROTOCOL=none &&
+ export GIT_ALLOW_PROTOCOL &&
+ test_must_fail git -c protocol.allow=always clone --bare "$url" tmp.git &&
+ test_must_fail git -c protocol.$proto.allow=always clone --bare "$url" tmp.git
+ )
+ '
+}
+
+test_config () {
+ desc=$1
+ proto=$2
+ url=$3
+
+ # Test clone/fetch/push with protocol.<type>.allow config
+ test_expect_success "clone $desc (enabled with config)" '
+ rm -rf tmp.git &&
+ git -c protocol.$proto.allow=always clone --bare "$url" tmp.git
+ '
+
+ test_expect_success "fetch $desc (enabled)" '
+ git -C tmp.git -c protocol.$proto.allow=always fetch
+ '
+
+ test_expect_success "push $desc (enabled)" '
+ git -C tmp.git -c protocol.$proto.allow=always push origin HEAD:pushed
+ '
+
+ test_expect_success "push $desc (disabled)" '
+ test_must_fail git -C tmp.git -c protocol.$proto.allow=never push origin HEAD:pushed
+ '
+
+ test_expect_success "fetch $desc (disabled)" '
+ test_must_fail git -C tmp.git -c protocol.$proto.allow=never fetch
+ '
+
+ test_expect_success "clone $desc (disabled)" '
+ rm -rf tmp.git &&
+ test_must_fail git -c protocol.$proto.allow=never clone --bare "$url" tmp.git
+ '
+
+ # Test clone/fetch/push with protocol.user.allow and its env var
+ test_expect_success "clone $desc (enabled)" '
+ rm -rf tmp.git &&
+ git -c protocol.$proto.allow=user clone --bare "$url" tmp.git
+ '
+
+ test_expect_success "fetch $desc (enabled)" '
+ git -C tmp.git -c protocol.$proto.allow=user fetch
+ '
+
+ test_expect_success "push $desc (enabled)" '
+ git -C tmp.git -c protocol.$proto.allow=user push origin HEAD:pushed
+ '
+
+ test_expect_success "push $desc (disabled)" '
+ (
+ cd tmp.git &&
+ GIT_PROTOCOL_FROM_USER=0 &&
+ export GIT_PROTOCOL_FROM_USER &&
+ test_must_fail git -c protocol.$proto.allow=user push origin HEAD:pushed
+ )
+ '
+
+ test_expect_success "fetch $desc (disabled)" '
+ (
+ cd tmp.git &&
+ GIT_PROTOCOL_FROM_USER=0 &&
+ export GIT_PROTOCOL_FROM_USER &&
+ test_must_fail git -c protocol.$proto.allow=user fetch
+ )
+ '
+
+ test_expect_success "clone $desc (disabled)" '
+ rm -rf tmp.git &&
+ (
+ GIT_PROTOCOL_FROM_USER=0 &&
+ export GIT_PROTOCOL_FROM_USER &&
+ test_must_fail git -c protocol.$proto.allow=user clone --bare "$url" tmp.git
+ )
+ '
+
+ # Test clone/fetch/push with protocol.allow user defined default
+ test_expect_success "clone $desc (enabled)" '
+ rm -rf tmp.git &&
+ git config --global protocol.allow always &&
+ git clone --bare "$url" tmp.git
+ '
+
+ test_expect_success "fetch $desc (enabled)" '
+ git -C tmp.git fetch
+ '
+
+ test_expect_success "push $desc (enabled)" '
+ git -C tmp.git push origin HEAD:pushed
+ '
+
+ test_expect_success "push $desc (disabled)" '
+ git config --global protocol.allow never &&
+ test_must_fail git -C tmp.git push origin HEAD:pushed
+ '
+
+ test_expect_success "fetch $desc (disabled)" '
+ test_must_fail git -C tmp.git fetch
+ '
+
+ test_expect_success "clone $desc (disabled)" '
+ rm -rf tmp.git &&
+ test_must_fail git clone --bare "$url" tmp.git
+ '
+}
+
+# test cloning a particular protocol
+# $1 - description of the protocol
+# $2 - machine-readable name of the protocol
+# $3 - the URL to try cloning
+test_proto () {
+ test_whitelist "$@"
+
+ test_config "$@"
}
# set up an ssh wrapper that will access $host/$repo in the
diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh
index bc44ac36d57..75c570adcae 100755
--- a/t/t5509-fetch-push-namespaces.sh
+++ b/t/t5509-fetch-push-namespaces.sh
@@ -4,6 +4,7 @@ test_description='fetch/push involving ref namespaces'
. ./test-lib.sh
test_expect_success setup '
+ git config --global protocol.ext.allow user &&
test_tick &&
git init original &&
(
diff --git a/t/t5802-connect-helper.sh b/t/t5802-connect-helper.sh
index b7a7f9d5886..c6c2661878c 100755
--- a/t/t5802-connect-helper.sh
+++ b/t/t5802-connect-helper.sh
@@ -4,6 +4,7 @@ test_description='ext::cmd remote "connect" helper'
. ./test-lib.sh
test_expect_success setup '
+ git config --global protocol.ext.allow user &&
test_tick &&
git commit --allow-empty -m initial &&
test_tick &&
diff --git a/transport.c b/transport.c
index dff929ec01f..fbd799d0625 100644
--- a/transport.c
+++ b/transport.c
@@ -617,10 +617,81 @@ static const struct string_list *protocol_whitelist(void)
return enabled ? &allowed : NULL;
}
+enum protocol_allow_config {
+ PROTOCOL_ALLOW_NEVER = 0,
+ PROTOCOL_ALLOW_USER_ONLY,
+ PROTOCOL_ALLOW_ALWAYS
+};
+
+static enum protocol_allow_config parse_protocol_config(const char *key,
+ const char *value)
+{
+ if (!strcasecmp(value, "always"))
+ return PROTOCOL_ALLOW_ALWAYS;
+ else if (!strcasecmp(value, "never"))
+ return PROTOCOL_ALLOW_NEVER;
+ else if (!strcasecmp(value, "user"))
+ return PROTOCOL_ALLOW_USER_ONLY;
+
+ die("unknown value for config '%s': %s", key, value);
+}
+
+static enum protocol_allow_config get_protocol_config(const char *type)
+{
+ char *key = xstrfmt("protocol.%s.allow", type);
+ char *value;
+
+ /* first check the per-protocol config */
+ if (!git_config_get_string(key, &value)) {
+ enum protocol_allow_config ret =
+ parse_protocol_config(key, value);
+ free(key);
+ free(value);
+ return ret;
+ }
+ free(key);
+
+ /* if defined, fallback to user-defined default for unknown protocols */
+ if (!git_config_get_string("protocol.allow", &value)) {
+ enum protocol_allow_config ret =
+ parse_protocol_config("protocol.allow", value);
+ free(value);
+ return ret;
+ }
+
+ /* fallback to built-in defaults */
+ /* known safe */
+ if (!strcmp(type, "http") ||
+ !strcmp(type, "https") ||
+ !strcmp(type, "git") ||
+ !strcmp(type, "ssh") ||
+ !strcmp(type, "file"))
+ return PROTOCOL_ALLOW_ALWAYS;
+
+ /* known scary; err on the side of caution */
+ if (!strcmp(type, "ext"))
+ return PROTOCOL_ALLOW_NEVER;
+
+ /* unknown; by default let them be used only directly by the user */
+ return PROTOCOL_ALLOW_USER_ONLY;
+}
+
int is_transport_allowed(const char *type)
{
- const struct string_list *allowed = protocol_whitelist();
- return !allowed || string_list_has_string(allowed, type);
+ const struct string_list *whitelist = protocol_whitelist();
+ if (whitelist)
+ return string_list_has_string(whitelist, type);
+
+ switch (get_protocol_config(type)) {
+ case PROTOCOL_ALLOW_ALWAYS:
+ return 1;
+ case PROTOCOL_ALLOW_NEVER:
+ return 0;
+ case PROTOCOL_ALLOW_USER_ONLY:
+ return git_env_bool("GIT_PROTOCOL_FROM_USER", 1);
+ }
+
+ die("BUG: invalid protocol_allow_config type");
}
void transport_check_allowed(const char *type)
From aeae4db1747d891dc3aee6a74508c585c321cc49 Mon Sep 17 00:00:00 2001
From: Brandon Williams <bmwill@google.com>
Date: Wed, 14 Dec 2016 14:39:53 -0800
Subject: [PATCH 4/6] http: create function to get curl allowed protocols
Move the creation of an allowed protocols whitelist to a helper
function. This will be useful when we need to compute the set of
allowed protocols differently for normal and redirect cases.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
http.c | 31 ++++++++++++++++++++-----------
1 file changed, 20 insertions(+), 11 deletions(-)
diff --git a/http.c b/http.c
index 034426e746f..f7c488af8b0 100644
--- a/http.c
+++ b/http.c
@@ -489,10 +489,25 @@ static void set_curl_keepalive(CURL *c)
}
#endif
+static long get_curl_allowed_protocols(void)
+{
+ long allowed_protocols = 0;
+
+ if (is_transport_allowed("http"))
+ allowed_protocols |= CURLPROTO_HTTP;
+ if (is_transport_allowed("https"))
+ allowed_protocols |= CURLPROTO_HTTPS;
+ if (is_transport_allowed("ftp"))
+ allowed_protocols |= CURLPROTO_FTP;
+ if (is_transport_allowed("ftps"))
+ allowed_protocols |= CURLPROTO_FTPS;
+
+ return allowed_protocols;
+}
+
static CURL *get_curl_handle(void)
{
CURL *result = curl_easy_init();
- long allowed_protocols = 0;
if (!result)
die("curl_easy_init failed");
@@ -572,16 +587,10 @@ static CURL *get_curl_handle(void)
curl_easy_setopt(result, CURLOPT_POST301, 1);
#endif
#if LIBCURL_VERSION_NUM >= 0x071304
- if (is_transport_allowed("http"))
- allowed_protocols |= CURLPROTO_HTTP;
- if (is_transport_allowed("https"))
- allowed_protocols |= CURLPROTO_HTTPS;
- if (is_transport_allowed("ftp"))
- allowed_protocols |= CURLPROTO_FTP;
- if (is_transport_allowed("ftps"))
- allowed_protocols |= CURLPROTO_FTPS;
- curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS, allowed_protocols);
- curl_easy_setopt(result, CURLOPT_PROTOCOLS, allowed_protocols);
+ curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS,
+ get_curl_allowed_protocols());
+ curl_easy_setopt(result, CURLOPT_PROTOCOLS,
+ get_curl_allowed_protocols());
#else
warning("protocol restrictions not applied to curl redirects because\n"
"your curl version is too old (>= 7.19.4)");
From a768a02265f3b8f43e37f66a0a3affba92c830c7 Mon Sep 17 00:00:00 2001
From: Brandon Williams <bmwill@google.com>
Date: Wed, 14 Dec 2016 14:39:54 -0800
Subject: [PATCH 5/6] transport: add from_user parameter to
is_transport_allowed
Add a from_user parameter to is_transport_allowed() to allow http to be
able to distinguish between protocol restrictions for redirects versus
initial requests. CURLOPT_REDIR_PROTOCOLS can now be set differently
from CURLOPT_PROTOCOLS to disallow use of protocols with the "user"
policy in redirects.
This change allows callers to query if a transport protocol is allowed,
given that the caller knows that the protocol is coming from the user
(1) or not from the user (0) such as redirects in libcurl. If unknown a
-1 should be provided which falls back to reading
`GIT_PROTOCOL_FROM_USER` to determine if the protocol came from the
user.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
http.c | 14 +++++++-------
t/t5812-proto-disable-http.sh | 7 +++++++
transport.c | 8 +++++---
transport.h | 13 ++++++++++---
4 files changed, 29 insertions(+), 13 deletions(-)
diff --git a/http.c b/http.c
index f7c488af8b0..2208269b33a 100644
--- a/http.c
+++ b/http.c
@@ -489,17 +489,17 @@ static void set_curl_keepalive(CURL *c)
}
#endif
-static long get_curl_allowed_protocols(void)
+static long get_curl_allowed_protocols(int from_user)
{
long allowed_protocols = 0;
- if (is_transport_allowed("http"))
+ if (is_transport_allowed("http", from_user))
allowed_protocols |= CURLPROTO_HTTP;
- if (is_transport_allowed("https"))
+ if (is_transport_allowed("https", from_user))
allowed_protocols |= CURLPROTO_HTTPS;
- if (is_transport_allowed("ftp"))
+ if (is_transport_allowed("ftp", from_user))
allowed_protocols |= CURLPROTO_FTP;
- if (is_transport_allowed("ftps"))
+ if (is_transport_allowed("ftps", from_user))
allowed_protocols |= CURLPROTO_FTPS;
return allowed_protocols;
@@ -588,9 +588,9 @@ static CURL *get_curl_handle(void)
#endif
#if LIBCURL_VERSION_NUM >= 0x071304
curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS,
- get_curl_allowed_protocols());
+ get_curl_allowed_protocols(0));
curl_easy_setopt(result, CURLOPT_PROTOCOLS,
- get_curl_allowed_protocols());
+ get_curl_allowed_protocols(-1));
#else
warning("protocol restrictions not applied to curl redirects because\n"
"your curl version is too old (>= 7.19.4)");
diff --git a/t/t5812-proto-disable-http.sh b/t/t5812-proto-disable-http.sh
index 044cc152f83..d911afd24cd 100755
--- a/t/t5812-proto-disable-http.sh
+++ b/t/t5812-proto-disable-http.sh
@@ -30,5 +30,12 @@ test_expect_success 'curl limits redirects' '
test_must_fail git clone "$HTTPD_URL/loop-redir/smart/repo.git"
'
+test_expect_success 'http can be limited to from-user' '
+ git -c protocol.http.allow=user \
+ clone "$HTTPD_URL/smart/repo.git" plain.git &&
+ test_must_fail git -c protocol.http.allow=user \
+ clone "$HTTPD_URL/smart-redir-perm/repo.git" redir.git
+'
+
stop_httpd
test_done
diff --git a/transport.c b/transport.c
index fbd799d0625..f50c31a572f 100644
--- a/transport.c
+++ b/transport.c
@@ -676,7 +676,7 @@ static enum protocol_allow_config get_protocol_config(const char *type)
return PROTOCOL_ALLOW_USER_ONLY;
}
-int is_transport_allowed(const char *type)
+int is_transport_allowed(const char *type, int from_user)
{
const struct string_list *whitelist = protocol_whitelist();
if (whitelist)
@@ -688,7 +688,9 @@ int is_transport_allowed(const char *type)
case PROTOCOL_ALLOW_NEVER:
return 0;
case PROTOCOL_ALLOW_USER_ONLY:
- return git_env_bool("GIT_PROTOCOL_FROM_USER", 1);
+ if (from_user < 0)
+ from_user = git_env_bool("GIT_PROTOCOL_FROM_USER", 1);
+ return from_user;
}
die("BUG: invalid protocol_allow_config type");
@@ -696,7 +698,7 @@ int is_transport_allowed(const char *type)
void transport_check_allowed(const char *type)
{
- if (!is_transport_allowed(type))
+ if (!is_transport_allowed(type, -1))
die("transport '%s' not allowed", type);
}
diff --git a/transport.h b/transport.h
index 3396e1d4340..4f1c801994f 100644
--- a/transport.h
+++ b/transport.h
@@ -142,10 +142,17 @@ struct transport {
struct transport *transport_get(struct remote *, const char *);
/*
- * Check whether a transport is allowed by the environment. Type should
- * generally be the URL scheme, as described in Documentation/git.txt
+ * Check whether a transport is allowed by the environment.
+ *
+ * Type should generally be the URL scheme, as described in
+ * Documentation/git.txt
+ *
+ * from_user specifies if the transport was given by the user. If unknown pass
+ * a -1 to read from the environment to determine if the transport was given by
+ * the user.
+ *
*/
-int is_transport_allowed(const char *type);
+int is_transport_allowed(const char *type, int from_user);
/*
* Check whether a transport is allowed by the environment,
From abcbdc03895ff3f00280e54af11fee92d6877044 Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Wed, 14 Dec 2016 14:39:55 -0800
Subject: [PATCH 6/6] http: respect protocol.*.allow=user for http-alternates
The http-walker may fetch the http-alternates (or
alternates) file from a remote in order to find more
objects. This should count as a "not from the user" use of
the protocol. But because we implement the redirection
ourselves and feed the new URL to curl, it will use the
CURLOPT_PROTOCOLS rules, not the more restrictive
CURLOPT_REDIR_PROTOCOLS.
The ideal solution would be for each curl request we make to
know whether or not is directly from the user or part of an
alternates redirect, and then set CURLOPT_PROTOCOLS as
appropriate. However, that would require plumbing that
information through all of the various layers of the http
code.
Instead, let's check the protocol at the source: when we are
parsing the remote http-alternates file. The only downside
is that if there's any mismatch between what protocol we
think it is versus what curl thinks it is, it could violate
the policy.
To address this, we'll make the parsing err on the picky
side, and only allow protocols that it can parse
definitively. So for example, you can't elude the "http"
policy by asking for "HTTP://", even though curl might
handle it; we would reject it as unknown. The only unsafe
case would be if you have a URL that starts with "http://"
but curl interprets as another protocol. That seems like an
unlikely failure mode (and we are still protected by our
base CURLOPT_PROTOCOL setting, so the worst you could do is
trigger one of https, ftp, or ftps).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
http-walker.c | 50 ++++++++++++++++++++++++++++++--------
t/t5550-http-fetch-dumb.sh | 10 ++++++++
2 files changed, 50 insertions(+), 10 deletions(-)
diff --git a/http-walker.c b/http-walker.c
index c2f81cd6af9..b34b6ace7cd 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -3,6 +3,7 @@
#include "walker.h"
#include "http.h"
#include "list.h"
+#include "transport.h"
struct alt_base {
char *base;
@@ -160,6 +161,32 @@ static void prefetch(struct walker *walker, unsigned char *sha1)
#endif
}
+static int is_alternate_allowed(const char *url)
+{
+ const char *protocols[] = {
+ "http", "https", "ftp", "ftps"
+ };
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(protocols); i++) {
+ const char *end;
+ if (skip_prefix(url, protocols[i], &end) &&
+ starts_with(end, "://"))
+ break;
+ }
+
+ if (i >= ARRAY_SIZE(protocols)) {
+ warning("ignoring alternate with unknown protocol: %s", url);
+ return 0;
+ }
+ if (!is_transport_allowed(protocols[i], 0)) {
+ warning("ignoring alternate with restricted protocol: %s", url);
+ return 0;
+ }
+
+ return 1;
+}
+
static void process_alternates_response(void *callback_data)
{
struct alternates_request *alt_req =
@@ -274,17 +301,20 @@ static void process_alternates_response(void *callback_data)
struct strbuf target = STRBUF_INIT;
strbuf_add(&target, base, serverlen);
strbuf_add(&target, data + i, posn - i - 7);
- warning("adding alternate object store: %s",
- target.buf);
- newalt = xmalloc(sizeof(*newalt));
- newalt->next = NULL;
- newalt->base = strbuf_detach(&target, NULL);
- newalt->got_indices = 0;
- newalt->packs = NULL;
- while (tail->next != NULL)
- tail = tail->next;
- tail->next = newalt;
+ if (is_alternate_allowed(target.buf)) {
+ warning("adding alternate object store: %s",
+ target.buf);
+ newalt = xmalloc(sizeof(*newalt));
+ newalt->next = NULL;
+ newalt->base = strbuf_detach(&target, NULL);
+ newalt->got_indices = 0;
+ newalt->packs = NULL;
+
+ while (tail->next != NULL)
+ tail = tail->next;
+ tail->next = newalt;
+ }
}
}
i = posn + 1;
diff --git a/t/t5550-http-fetch-dumb.sh b/t/t5550-http-fetch-dumb.sh
index 22011f0b688..c0ee29c65df 100755
--- a/t/t5550-http-fetch-dumb.sh
+++ b/t/t5550-http-fetch-dumb.sh
@@ -360,5 +360,15 @@ test_expect_success 'http-alternates cannot point at funny protocols' '
clone "$HTTPD_URL/dumb/evil.git" evil-file
'
+test_expect_success 'http-alternates triggers not-from-user protocol check' '
+ echo "$HTTPD_URL/dumb/victim.git/objects" \
+ >"$evil/objects/info/http-alternates" &&
+ test_config_global http.followRedirects true &&
+ test_must_fail git -c protocol.http.allow=user \
+ clone $HTTPD_URL/dumb/evil.git evil-user &&
+ git -c protocol.http.allow=always \
+ clone $HTTPD_URL/dumb/evil.git evil-user
+'
+
stop_httpd
test_done