lib/repo: Search a list of paths in gpgkeypath for gpg keys

This allows specifying gpgpath as list of
paths that can point to a file or a directory. If a directory path
is given, paths to all regular files in the directory are added
to the remote as gpg ascii keys. If the path is not a directory,
the file is directly added (whether regular file, empty - errors
will be reported later when verifying gpg keys e.g. when pulling).

Adding the gpgkeypath property looks like:

ostree --repo=repo remote add --set=gpgpath="/path/key1.asc,/path/keys.d" R1 https://example.com/some/remote/ostree/repo

Closes ostreedev#773

src/libostree/ostree-gpg-verifier.c

@@ -304,6 +304,70 @@ _ostree_gpg_verifier_add_key_ascii_file (OstreeGpgVerifier *self,
   g_ptr_array_add (self->key_ascii_files, g_strdup (path));
 }
 
+/* Check if the file at @path is a directory, and add ascii key files that
+ * exist one level below the directory. If @path does not lead to a directory,
+ * the file is added.
+ */
+void
+_ostree_gpg_verifier_add_key_ascii_files_check_dir (OstreeGpgVerifier *self,
+                                                    const char        *path,
+                                                    GCancellable      *cancellable,
+                                                    GError           **error)
+{
+  GFile *file;
+  GFileType file_type;
+
+  file = g_file_new_for_path (path);
+  file_type = g_file_query_file_type (file, G_FILE_QUERY_INFO_NONE, cancellable);
+
+  if (file_type == G_FILE_TYPE_DIRECTORY)
+    {
+      GFileEnumerator *direnum;
+      g_autofree char *sep = NULL;
+
+      if (!g_str_has_suffix (path, "/"))
+        sep = g_strdup ("/");
+
+      direnum = g_file_enumerate_children (file, OSTREE_GIO_FAST_QUERYINFO,
+                                          G_FILE_QUERY_INFO_NONE, cancellable, error);
+      if (direnum)
+        {
+          while (TRUE)
+            {
+              GFileInfo *child_info;
+              GFile *child;
+              const char *name;
+              guint32 type;
+
+              if (!g_file_enumerator_iterate (direnum, &child_info, &child,
+                                              NULL, error))
+                break;
+              if (child_info == NULL)
+                break;
+
+              name = g_file_info_get_attribute_byte_string (child_info, "standard::name");
+              type = g_file_info_get_attribute_uint32 (child_info, "standard::type");
+
+              if (type == G_FILE_TYPE_REGULAR)
+                {
+                  g_autofree char *child_path = NULL;
+
+                  child_path = g_strjoin (sep, path, name, NULL);
+
+                  _ostree_gpg_verifier_add_key_ascii_file (self, child_path);
+                }
+            }
+        }
+
+      g_object_unref (direnum);
+      g_object_unref (file);
+    }
+  else
+    {
+      _ostree_gpg_verifier_add_key_ascii_file (self, path);
+    }
+}
+
 gboolean
 _ostree_gpg_verifier_add_keyring_dir (OstreeGpgVerifier   *self,
                                       GFile               *path,

src/libostree/ostree-gpg-verifier.h

@@ -75,4 +75,10 @@ void _ostree_gpg_verifier_add_keyring_file (OstreeGpgVerifier *self,
 void _ostree_gpg_verifier_add_key_ascii_file (OstreeGpgVerifier *self,
                                               const char        *path);
 
+void
+_ostree_gpg_verifier_add_key_ascii_files_check_dir (OstreeGpgVerifier *self,
+                                                    const char        *path,
+                                                    GCancellable      *cancellable,
+                                                    GError           **error);
+
 G_END_DECLS

src/libostree/ostree-repo.c

@@ -5082,6 +5082,8 @@ _ostree_repo_gpg_verify_data_internal (OstreeRepo    *self,
   else if (remote_name != NULL)
     {
       g_autofree char *gpgkeypath = NULL;
+      char **gpgkeypath_list = NULL;
+
       /* Add the remote's keyring file if it exists. */
 
       g_autoptr(OstreeRemote) remote = NULL;
@@ -5105,7 +5107,26 @@ _ostree_repo_gpg_verify_data_internal (OstreeRepo    *self,
         return NULL;
 
       if (gpgkeypath)
-        _ostree_gpg_verifier_add_key_ascii_file (verifier, gpgkeypath);
+        {
+          if (strchr (gpgkeypath, ';'))
+            {
+              gpgkeypath_list = g_strsplit (gpgkeypath, ";", -1);
+            }
+          else
+            {
+              _ostree_gpg_verifier_add_key_ascii_files_check_dir (verifier, gpgkeypath, cancellable, error);
+            }
+        }
+
+      if (gpgkeypath_list)
+        {
+          for (char **iter = gpgkeypath_list; *iter != NULL; ++iter)
+            {
+              _ostree_gpg_verifier_add_key_ascii_files_check_dir (verifier, *iter, cancellable, error);
+            }
+        }
+
+      g_strfreev (gpgkeypath_list);
     }
 
   if (add_global_keyring_dir)

tests/test-remote-gpg-import.sh

@@ -154,6 +154,64 @@ ${OSTREE} prune --refs-only
 ${OSTREE} remote add --set=gpgkeypath=${test_tmpdir}/gpghome/key3.asc R4 $(cat httpd-address)/ostree/gnomerepo
 ${OSTREE} pull R4:main >/dev/null
 
+# Test gpgkeypath success with multiple keys to try
+${OSTREE} remote add --set=gpgkeypath="${test_tmpdir}/gpghome/key1.asc;${test_tmpdir}/gpghome/key2.asc;${test_tmpdir}/gpghome/key3.asc" R7 $(cat httpd-address)/ostree/gnomerepo
+${OSTREE} pull R7:main >/dev/null
+
+# Test gpgkeypath failure with multiple keys but none in keyring (invalid)
+${OSTREE} remote add --set=gpgkeypath="${test_tmpdir}/gpghome/key1.asc;${test_tmpdir}/gpghome/key2.asc" R8 $(cat httpd-address)/ostree/gnomerepo
+if ${OSTREE} pull R8:main 2>err.txt; then
+    assert_not_reached "Unexpectedly succeeded at pulling with different key"
+fi
+assert_file_has_content err.txt "GPG signatures found, but none are in trusted keyring"
+
+# Test gpgkeypath success with directory containing a valid key
+${OSTREE} remote add --set=gpgkeypath=${test_tmpdir}/gpghome/ R9 $(cat httpd-address)/ostree/gnomerepo
+${OSTREE} pull R9:main >/dev/null
+
+# Test gpgkeypath failure with nonexistent directory
+${OSTREE} remote add --set=gpgkeypath=${test_tmpdir}/gpghome/INVALIDKEYDIRPATH/ R10 $(cat httpd-address)/ostree/gnomerepo
+if ${OSTREE} pull R10:main 2>err.txt; then
+    assert_not_reached "Unexpectedly succeeded at pulling with nonexistent key directory"
+fi
+assert_file_has_content err.txt "GPG: openat.*No such file or directory"
+
+# Test gpgkeypath failure with a directory containing a valid key and a nonexistent key
+${OSTREE} remote add --set=gpgkeypath="${test_tmpdir}/gpghome/;${test_tmpdir}/gpghome/INVALIDKEYPATH.asc" R11 $(cat httpd-address)/ostree/gnomerepo
+if ${OSTREE} pull R11:main 2>err.txt; then
+    assert_not_reached "Unexpectedly succeeded at pulling with nonexistent key"
+fi
+assert_file_has_content err.txt "GPG: openat.*No such file or directory"
+
+# Test gpgkeypath success with a directory containing a valid key and an invalid key
+${OSTREE} remote add --set=gpgkeypath="${test_tmpdir}/gpghome/;${test_tmpdir}/gpghome/key1.asc" R14 $(cat httpd-address)/ostree/gnomerepo
+${OSTREE} pull R14:main >/dev/null
+
+# Test gpgkeypath failure with a nonexistent directory and a valid key
+${OSTREE} remote add --set=gpgkeypath="${test_tmpdir}/gpghome/INVALIDKEYDIRPATH/;${test_tmpdir}/gpghome/key3.asc" R12 $(cat httpd-address)/ostree/gnomerepo
+if ${OSTREE} pull R12:main 2>err.txt; then
+    assert_not_reached "Unexpectedly succeeded at pulling with nonexistent key directory"
+fi
+assert_file_has_content err.txt "GPG: openat.*No such file or directory"
+
+# Test gpgkeypath failure with a nonexistent directory and a nonexistent key
+${OSTREE} remote add --set=gpgkeypath="${test_tmpdir}/gpghome/INVALIDKEYDIRPATH/;${test_tmpdir}/gpghome/INVALIDKEYPATH.asc" R13 $(cat httpd-address)/ostree/gnomerepo
+if ${OSTREE} pull R13:main 2>err.txt; then
+    assert_not_reached "Unexpectedly succeeded at pulling with nonexistent key directory"
+fi
+assert_file_has_content err.txt "GPG: openat.*No such file or directory"
+
+# Test gpgkeypath success for trailing slash
+${OSTREE} remote add --set=gpgkeypath="${test_tmpdir}/gpghome" R15 $(cat httpd-address)/ostree/gnomerepo
+${OSTREE} pull R15:main >/dev/null
+
+# Test gpgkeypath failure for empty string given with prefixed semicolon
+${OSTREE} remote add --set=gpgkeypath=";${test_tmpdir}/gpghome/key3.asc" R16 $(cat httpd-address)/ostree/gnomerepo
+if ${OSTREE} pull R16:main 2>err.txt; then
+    assert_not_reached "Unexpectedly succeeded at pulling with nonexistent key directory"
+fi
+assert_file_has_content err.txt "GPG: openat.*No such file or directory"
+
 rm repo/refs/remotes/* -rf
 ${OSTREE} prune --refs-only