From: Victoria Dye <vdye@xxxxxxxxxx>
Move 'check_submodule_url' out of 'fsck.c' and into 'submodule-config.h' as
a public method, similar to 'check_submodule_name'. With the function now
accessible outside of 'fsck', it can be used in a later commit to extend
'test-tool submodule' to check the validity of submodule URLs as it does
with names in the 'check-name' subcommand.
Other than its location, no changes are made to 'check_submodule_url' in
this patch.
Signed-off-by: Victoria Dye <vdye@xxxxxxxxxx>
---
fsck.c | 133 --------------------------------------------
submodule-config.c | 134 +++++++++++++++++++++++++++++++++++++++++++++
submodule-config.h | 3 +
3 files changed, 137 insertions(+), 133 deletions(-)
diff --git a/fsck.c b/fsck.c
index 1ad02fcdfab..8ded0a473a4 100644
--- a/fsck.c
+++ b/fsck.c
@@ -20,7 +20,6 @@
#include "packfile.h"
#include "submodule-config.h"
#include "config.h"
-#include "credential.h"
#include "help.h"
static ssize_t max_tree_entry_len = 4096;
@@ -1047,138 +1046,6 @@ done:
return ret;
}
-static int starts_with_dot_slash(const char *const path)
-{
- return path_match_flags(path, PATH_MATCH_STARTS_WITH_DOT_SLASH |
- PATH_MATCH_XPLATFORM);
-}
-
-static int starts_with_dot_dot_slash(const char *const path)
-{
- return path_match_flags(path, PATH_MATCH_STARTS_WITH_DOT_DOT_SLASH |
- PATH_MATCH_XPLATFORM);
-}
-
-static int submodule_url_is_relative(const char *url)
-{
- return starts_with_dot_slash(url) || starts_with_dot_dot_slash(url);
-}
-
-/*
- * Count directory components that a relative submodule URL should chop
- * from the remote_url it is to be resolved against.
- *
- * In other words, this counts "../" components at the start of a
- * submodule URL.
- *
- * Returns the number of directory components to chop and writes a
- * pointer to the next character of url after all leading "./" and
- * "../" components to out.
- */
-static int count_leading_dotdots(const char *url, const char **out)
-{
- int result = 0;
- while (1) {
- if (starts_with_dot_dot_slash(url)) {
- result++;
- url += strlen("../");
- continue;
- }
- if (starts_with_dot_slash(url)) {
- url += strlen("./");
- continue;
- }
- *out = url;
- return result;
- }
-}
-/*
- * Check whether a transport is implemented by git-remote-curl.
- *
- * If it is, returns 1 and writes the URL that would be passed to
- * git-remote-curl to the "out" parameter.
- *
- * Otherwise, returns 0 and leaves "out" untouched.
- *
- * Examples:
- * http::https://example.com/repo.git -> 1, https://example.com/repo.git
- * https://example.com/repo.git -> 1, https://example.com/repo.git
- * git://example.com/repo.git -> 0
- *
- * This is for use in checking for previously exploitable bugs that
- * required a submodule URL to be passed to git-remote-curl.
- */
-static int url_to_curl_url(const char *url, const char **out)
-{
- /*
- * We don't need to check for case-aliases, "http.exe", and so
- * on because in the default configuration, is_transport_allowed
- * prevents URLs with those schemes from being cloned
- * automatically.
- */
- if (skip_prefix(url, "http::", out) ||
- skip_prefix(url, "https::", out) ||
- skip_prefix(url, "ftp::", out) ||
- skip_prefix(url, "ftps::", out))
- return 1;
- if (starts_with(url, "http://";) ||
- starts_with(url, "https://";) ||
- starts_with(url, "ftp://";) ||
- starts_with(url, "ftps://")) {
- *out = url;
- return 1;
- }
- return 0;
-}
-
-static int check_submodule_url(const char *url)
-{
- const char *curl_url;
-
- if (looks_like_command_line_option(url))
- return -1;
-
- if (submodule_url_is_relative(url) || starts_with(url, "git://")) {
- char *decoded;
- const char *next;
- int has_nl;
-
- /*
- * This could be appended to an http URL and url-decoded;
- * check for malicious characters.
- */
- decoded = url_decode(url);
- has_nl = !!strchr(decoded, '\n');
-
- free(decoded);
- if (has_nl)
- return -1;
-
- /*
- * URLs which escape their root via "../" can overwrite
- * the host field and previous components, resolving to
- * URLs like https::example.com/submodule.git and
- * https:///example.com/submodule.git that were
- * susceptible to CVE-2020-11008.
- */
- if (count_leading_dotdots(url, &next) > 0 &&
- (*next == ':' || *next == '/'))
- return -1;
- }
-
- else if (url_to_curl_url(url, &curl_url)) {
- struct credential c = CREDENTIAL_INIT;
- int ret = 0;
- if (credential_from_url_gently(&c, curl_url, 1) ||
- !*c.host)
- ret = -1;
- credential_clear(&c);
- return ret;
- }
-
- return 0;
-}
-
struct fsck_gitmodules_data {
const struct object_id *oid;
struct fsck_options *options;
diff --git a/submodule-config.c b/submodule-config.c
index f4dd482abc9..3b295e9f89c 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -14,6 +14,8 @@
#include "parse-options.h"
#include "thread-utils.h"
#include "tree-walk.h"
+#include "url.h"
+#include "credential.h"
/*
* submodule cache lookup structure
@@ -228,6 +230,138 @@ in_component:
return 0;
}
+static int starts_with_dot_slash(const char *const path)
+{
+ return path_match_flags(path, PATH_MATCH_STARTS_WITH_DOT_SLASH |
+ PATH_MATCH_XPLATFORM);
+}
+
+static int starts_with_dot_dot_slash(const char *const path)
+{
+ return path_match_flags(path, PATH_MATCH_STARTS_WITH_DOT_DOT_SLASH |
+ PATH_MATCH_XPLATFORM);
+}
+
+static int submodule_url_is_relative(const char *url)
+{
+ return starts_with_dot_slash(url) || starts_with_dot_dot_slash(url);
+}
+
+/*
+ * Count directory components that a relative submodule URL should chop
+ * from the remote_url it is to be resolved against.
+ *
+ * In other words, this counts "../" components at the start of a
+ * submodule URL.
+ *
+ * Returns the number of directory components to chop and writes a
+ * pointer to the next character of url after all leading "./" and
+ * "../" components to out.
+ */
+static int count_leading_dotdots(const char *url, const char **out)
+{
+ int result = 0;
+ while (1) {
+ if (starts_with_dot_dot_slash(url)) {
+ result++;
+ url += strlen("../");
+ continue;
+ }
+ if (starts_with_dot_slash(url)) {
+ url += strlen("./");
+ continue;
+ }
+ *out = url;
+ return result;
+ }
+}
+/*
+ * Check whether a transport is implemented by git-remote-curl.
+ *
+ * If it is, returns 1 and writes the URL that would be passed to
+ * git-remote-curl to the "out" parameter.
+ *
+ * Otherwise, returns 0 and leaves "out" untouched.
+ *
+ * Examples:
+ * http::https://example.com/repo.git -> 1, https://example.com/repo.git
+ * https://example.com/repo.git -> 1, https://example.com/repo.git
+ * git://example.com/repo.git -> 0
+ *
+ * This is for use in checking for previously exploitable bugs that
+ * required a submodule URL to be passed to git-remote-curl.
+ */
+static int url_to_curl_url(const char *url, const char **out)
+{
+ /*
+ * We don't need to check for case-aliases, "http.exe", and so
+ * on because in the default configuration, is_transport_allowed
+ * prevents URLs with those schemes from being cloned
+ * automatically.
+ */
+ if (skip_prefix(url, "http::", out) ||
+ skip_prefix(url, "https::", out) ||
+ skip_prefix(url, "ftp::", out) ||
+ skip_prefix(url, "ftps::", out))
+ return 1;
+ if (starts_with(url, "http://";) ||
+ starts_with(url, "https://";) ||
+ starts_with(url, "ftp://";) ||
+ starts_with(url, "ftps://")) {
+ *out = url;
+ return 1;
+ }
+ return 0;
+}
+
+int check_submodule_url(const char *url)
+{
+ const char *curl_url;
+
+ if (looks_like_command_line_option(url))
+ return -1;
+
+ if (submodule_url_is_relative(url) || starts_with(url, "git://")) {
+ char *decoded;
+ const char *next;
+ int has_nl;
+
+ /*
+ * This could be appended to an http URL and url-decoded;
+ * check for malicious characters.
+ */
+ decoded = url_decode(url);
+ has_nl = !!strchr(decoded, '\n');
+
+ free(decoded);
+ if (has_nl)
+ return -1;
+
+ /*
+ * URLs which escape their root via "../" can overwrite
+ * the host field and previous components, resolving to
+ * URLs like https::example.com/submodule.git and
+ * https:///example.com/submodule.git that were
+ * susceptible to CVE-2020-11008.
+ */
+ if (count_leading_dotdots(url, &next) > 0 &&
+ (*next == ':' || *next == '/'))
+ return -1;
+ }
+
+ else if (url_to_curl_url(url, &curl_url)) {
+ struct credential c = CREDENTIAL_INIT;
+ int ret = 0;
+ if (credential_from_url_gently(&c, curl_url, 1) ||
+ !*c.host)
+ ret = -1;
+ credential_clear(&c);
+ return ret;
+ }
+
+ return 0;
+}
+
static int name_and_item_from_var(const char *var, struct strbuf *name,
struct strbuf *item)
{
diff --git a/submodule-config.h b/submodule-config.h
index 958f320ac6c..b6133af71b0 100644
--- a/submodule-config.h
+++ b/submodule-config.h
@@ -89,6 +89,9 @@ int config_set_in_gitmodules_file_gently(const char *key, const char *value);
*/
int check_submodule_name(const char *name);
+/* Returns 0 if the URL valid per RFC3986 and -1 otherwise. */
+int check_submodule_url(const char *url);
+
/*
* Note: these helper functions exist solely to maintain backward
* compatibility with 'fetch' and 'update_clone' storing configuration in
--
gitgitgadget
