contrib: add scp81 OTA trigger builder

Change-Id: Ic646626319cd7a26195d0ffff55900032abcddeb
---
A contrib/scp81_trigger.py
1 file changed, 99 insertions(+), 0 deletions(-)


git pull ssh://gerrit.osmocom.org:29418/pysim refs/changes/66/43566/1

diff --git a/contrib/scp81_trigger.py b/contrib/scp81_trigger.py
new file mode 100644
index 0000000..00cd269
--- /dev/null
+++ b/contrib/scp81_trigger.py
@@ -0,0 +1,99 @@
+#!/usr/bin/env python3
+"""scp81_trigger.py -- build the OTA packet that asks the card to open an SCP81 admin session."""
+
+# (C) 2026 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+#
+# Author: Eric Wild
+#
+# 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/>.
+
+
+# Prints the apdu line for AdmSessTriggerParams TLV as the sms secured data, Expanded RFM mode,
+# to be fed into pysim_shell.py
+#
+# security params supplied either
+# - in the trigger
+# - from the cards data object,
+# trigger wins when both are present.
+# --no-sec omits them from the trigger so the stored ones are used.
+#
+# example params:
+#    --psk-id 'PSK Identity 123' --kvn 0x41 --kid-ref 5
+#    --ip 127.0.0.1 --port 8080 --buffer 512
+#    --host 172.96.0.1 --uri '/server/adminagent?cmd=1'
+
+import argparse
+import sys
+
+from osmocom.utils import b2h                                          # noqa: E402
+from pySim.cat import (sms_pp_download_envelope, BearerDescription,  # noqa: E402
+                       BufferSize, UiccTransportLevel, OtherAddress)
+from pySim.global_platform.http import (AdmSessTriggerParams, AdmSessionParams,  # noqa: E402
+                                        SecurityParams, HttpPostParams, RasConnectionParams,
+                                        AdminHostParam, AdminUriParam)
+
+
+def main():
+    ap = argparse.ArgumentParser(description=__doc__,
+                                 formatter_class=argparse.RawDescriptionHelpFormatter)
+    ap.add_argument("--psk-id", help="PSK identity for ClientHello (required unless --no-sec)")
+    ap.add_argument("--kvn", type=lambda s: int(s, 0), help="key version of the PSK (required unless --no-sec)")
+    ap.add_argument("--kid-ref", type=lambda s: int(s, 0), help="PSK key id (required unless --no-sec)")
+    ap.add_argument("--host", help="HTTP Host header (required unless --no-http)")
+    ap.add_argument("--uri", help="HTTP request URI (required unless --no-http)")
+    ap.add_argument("--ip", help="administration server address, BIP (required unless --no-conn)")
+    ap.add_argument("--port", type=int, help="administration server port (required unless --no-conn)")
+    ap.add_argument("--buffer", type=int, help="BIP buffer size (required unless --no-conn)")
+    ap.add_argument("--no-conn", action="store_true", help="omit the connection params (tag 0x84)")
+    ap.add_argument("--no-sec", action="store_true", help="omit the security params (tag 0x85)")
+    ap.add_argument("--no-http", action="store_true", help="omit the HTTP POST params (tag 0x89)")
+
+    args = ap.parse_args()
+
+    missing = []
+    if not args.no_conn:
+        missing += [n for n in ('ip', 'port', 'buffer') if getattr(args, n) is None]
+    if not args.no_sec:
+        missing += [n for n in ('psk_id', 'kvn', 'kid_ref') if getattr(args, n) is None]
+    if not args.no_http:
+        missing += [n for n in ('host', 'uri') if getattr(args, n) is None]
+    if missing:
+        ap.error("pass every value required: %s." % " ".join("--" + n.replace('_', '-') for n in missing))
+
+    session = []
+    if not args.no_conn:
+        session.append(RasConnectionParams(children=[
+            BearerDescription(decoded={'bearer_type': 'default', 'bearer_parameters': ''}),
+            BufferSize(decoded=args.buffer),
+            UiccTransportLevel(decoded={'protocol_type': 'tcp_uicc_client_remote',
+                                        'port_number': args.port}),
+            OtherAddress(decoded={'type_of_address': 'ipv4',
+                                  'address': bytes(int(b) for b in args.ip.split("."))})]))
+    if not args.no_sec:
+        session.append(SecurityParams(decoded={'psk_id': args.psk_id.encode(), 'kvn': args.kvn,
+                                               'kid': args.kid_ref, 'sha_type': None}))
+    if not args.no_http:
+        session.append(HttpPostParams(children=[AdminHostParam(decoded=args.host),
+                                                AdminUriParam(decoded=args.uri)]))
+    trig = AdmSessTriggerParams(children=[AdmSessionParams(children=session)]).to_tlv()
+
+    # stderr for logs, stdout for data
+    print("# trigger TLV   %d B  %s" % (len(trig), trig.hex()), file=sys.stderr)
+    print("# %-13s %d B  %s" % ("secured data", len(trig), trig.hex()), file=sys.stderr)
+    print(trig.hex())
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

