pySim-shell: JSONpath support for updating files/records
Change-Id: Iad09b3d878b8b58ad34cb549c80f8a6eb3149faa
diff --git a/pySim/filesystem.py b/pySim/filesystem.py
index a65a764..f8443f3 100644
--- a/pySim/filesystem.py
+++ b/pySim/filesystem.py
@@ -35,6 +35,7 @@
from pySim.utils import sw_match, h2b, b2h, is_hex
from pySim.exceptions import *
+from pySim.jsonpath import js_path_find, js_path_modify
class CardFile(object):
"""Base class for all objects in the smart card filesystem.
@@ -418,10 +419,16 @@
upd_bin_dec_parser = argparse.ArgumentParser()
upd_bin_dec_parser.add_argument('data', help='Abstract data (JSON format) to write')
+ upd_bin_dec_parser.add_argument('--json-path', type=str,
+ help='JSON path to modify specific element of file only')
@cmd2.with_argparser(upd_bin_dec_parser)
def do_update_binary_decoded(self, opts):
"""Encode + Update (Write) data of a transparent EF"""
- data_json = json.loads(opts.data)
+ if opts.json_path:
+ (data_json, sw) = self._cmd.rs.read_binary_dec()
+ js_path_modify(data_json, opts.json_path, json.loads(opts.data))
+ else:
+ data_json = json.loads(opts.data)
(data, sw) = self._cmd.rs.update_binary_dec(data_json)
if data:
self._cmd.poutput_json(data)
@@ -574,10 +581,17 @@
upd_rec_dec_parser = argparse.ArgumentParser()
upd_rec_dec_parser.add_argument('record_nr', type=int, help='Number of record to be read')
upd_rec_dec_parser.add_argument('data', help='Data bytes (hex format) to write')
+ upd_rec_dec_parser.add_argument('--json-path', type=str,
+ help='JSON path to modify specific element of record only')
@cmd2.with_argparser(upd_rec_dec_parser)
def do_update_record_decoded(self, opts):
"""Encode + Update (write) data to a record-oriented EF"""
- (data, sw) = self._cmd.rs.update_record_dec(opts.record_nr, opts.data)
+ if opts.json_path:
+ (data_json, sw) = self._cmd.rs.read_record_dec(opts.record_nr)
+ js_path_modify(data_json, opts.json_path, json.loads(opts.data))
+ else:
+ data_json = json.loads(opts.data)
+ (data, sw) = self._cmd.rs.update_record_dec(opts.record_nr, data_json)
if data:
self._cmd.poutput(data)
diff --git a/pySim/jsonpath.py b/pySim/jsonpath.py
new file mode 100644
index 0000000..98dbd75
--- /dev/null
+++ b/pySim/jsonpath.py
@@ -0,0 +1,48 @@
+# coding=utf-8
+import json
+import pprint
+import jsonpath_ng
+
+"""JSONpath utility functions as needed within pysim.
+
+As pySim-sell has the ability to represent SIM files as JSON strings,
+adding JSONpath allows us to conveniently modify individual sub-fields
+of a file or record in its JSON representation.
+"""
+
+# (C) 2021 by Harald Welte <laforge@osmocom.org>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+def js_path_find(js_dict, js_path):
+ """Find/Match a JSON path within a given JSON-serializable dict.
+ Args:
+ js_dict : JSON-serializable dict to operate on
+ js_path : JSONpath string
+ Returns: Result of the JSONpath expression
+ """
+ jsonpath_expr = jsonpath_ng.parse(js_path)
+ return jsonpath_expr.find(js_dict)
+
+def js_path_modify(js_dict, js_path, new_val):
+ """Find/Match a JSON path within a given JSON-serializable dict.
+ Args:
+ js_dict : JSON-serializable dict to operate on
+ js_path : JSONpath string
+ new_val : New value for field in js_dict at js_path
+ """
+ jsonpath_expr = jsonpath_ng.parse(js_path)
+ jsonpath_expr.find(js_dict)
+ jsonpath_expr.update(js_dict, new_val)
+