Merge branch 'bw/transport-protocol-policy'

Finer-grained control of what protocols are allowed for transports
during clone/fetch/push have been enabled via a new configuration
mechanism.

* bw/transport-protocol-policy:
  http: respect protocol.*.allow=user for http-alternates
  transport: add from_user parameter to is_transport_allowed
  http: create function to get curl allowed protocols
  transport: add protocol policy config option
  http: always warn if libcurl version is too old
  lib-proto-disable: variable name fix

2 files changed, 60 insertions, 24 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index d51182a060..30cb946104 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -2318,6 +2318,52 @@ 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 98033302bb..ba222f68cc 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -1161,30 +1161,20 @@ 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]]
 ------------------------