1 files changed, 58 insertions, 16 deletions

diff --git a/transport.c b/transport.c
index eca9b8c..863eb52 100644
--- a/transport.c
+++ b/transport.c
@@ -278,12 +278,11 @@ static int fetch_objs_via_rsync(struct transport *transport,
 	return run_command(&rsync);
 }
 
-static int write_one_ref(const char *name, const unsigned char *sha1,
-		int flags, void *data)
+static int write_one_ref(const char *name, const struct object_id *oid,
+			 int flags, void *data)
 {
 	struct strbuf *buf = data;
 	int len = buf->len;
-	FILE *f;
 
 	/* when called via for_each_ref(), flags is non-zero */
 	if (flags && !starts_with(name, "refs/heads/") &&
@@ -292,27 +291,26 @@ static int write_one_ref(const char *name, const unsigned char *sha1,
 
 	strbuf_addstr(buf, name);
 	if (safe_create_leading_directories(buf->buf) ||
-			!(f = fopen(buf->buf, "w")) ||
-			fprintf(f, "%s\n", sha1_to_hex(sha1)) < 0 ||
-			fclose(f))
-		return error("problems writing temporary file %s", buf->buf);
+	    write_file_gently(buf->buf, "%s", oid_to_hex(oid)))
+		return error("problems writing temporary file %s: %s",
+			     buf->buf, strerror(errno));
 	strbuf_setlen(buf, len);
 	return 0;
 }
 
 static int write_refs_to_temp_dir(struct strbuf *temp_dir,
-		int refspec_nr, const char **refspec)
+				  int refspec_nr, const char **refspec)
 {
 	int i;
 
 	for (i = 0; i < refspec_nr; i++) {
-		unsigned char sha1[20];
+		struct object_id oid;
 		char *ref;
 
-		if (dwim_ref(refspec[i], strlen(refspec[i]), sha1, &ref) != 1)
+		if (dwim_ref(refspec[i], strlen(refspec[i]), oid.hash, &ref) != 1)
 			return error("Could not get ref %s", refspec[i]);
 
-		if (write_one_ref(ref, sha1, 0, temp_dir)) {
+		if (write_one_ref(ref, &oid, 0, temp_dir)) {
 			free(ref);
 			return -1;
 		}
@@ -478,9 +476,6 @@ static int set_git_option(struct git_transport_options *opts,
 				die("transport: invalid depth option '%s'", value);
 		}
 		return 0;
-	} else if (!strcmp(name, TRANS_OPT_PUSH_CERT)) {
-		opts->push_cert = !!value;
-		return 0;
 	}
 	return 1;
 }
@@ -831,10 +826,16 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 	args.progress = transport->progress;
 	args.dry_run = !!(flags & TRANSPORT_PUSH_DRY_RUN);
 	args.porcelain = !!(flags & TRANSPORT_PUSH_PORCELAIN);
-	args.push_cert = !!(flags & TRANSPORT_PUSH_CERT);
 	args.atomic = !!(flags & TRANSPORT_PUSH_ATOMIC);
 	args.url = transport->url;
 
+	if (flags & TRANSPORT_PUSH_CERT_ALWAYS)
+		args.push_cert = SEND_PACK_PUSH_CERT_ALWAYS;
+	else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED)
+		args.push_cert = SEND_PACK_PUSH_CERT_IF_ASKED;
+	else
+		args.push_cert = SEND_PACK_PUSH_CERT_NEVER;
+
 	ret = send_pack(&args, data->fd, data->conn, remote_refs,
 			&data->extra_have);
 
@@ -914,6 +915,42 @@ static int external_specification_len(const char *url)
 	return strchr(url, ':') - url;
 }
 
+static const struct string_list *protocol_whitelist(void)
+{
+	static int enabled = -1;
+	static struct string_list allowed = STRING_LIST_INIT_DUP;
+
+	if (enabled < 0) {
+		const char *v = getenv("GIT_ALLOW_PROTOCOL");
+		if (v) {
+			string_list_split(&allowed, v, ':', -1);
+			string_list_sort(&allowed);
+			enabled = 1;
+		} else {
+			enabled = 0;
+		}
+	}
+
+	return enabled ? &allowed : NULL;
+}
+
+int is_transport_allowed(const char *type)
+{
+	const struct string_list *allowed = protocol_whitelist();
+	return !allowed || string_list_has_string(allowed, type);
+}
+
+void transport_check_allowed(const char *type)
+{
+	if (!is_transport_allowed(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;
@@ -945,12 +982,14 @@ 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;
@@ -962,7 +1001,10 @@ 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;