add contrib/eidtool.py: Tool for checking + computing EID checksum

Change-Id: If6c560a2de51718948fb99b816e080f2aff4d0ed
---
A contrib/eidtool.py
1 file changed, 82 insertions(+), 0 deletions(-)

diff --git a/contrib/eidtool.py b/contrib/eidtool.py
new file mode 100755
index 0000000..cd5992b
--- /dev/null
+++ b/contrib/eidtool.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+
+# Command line tool to compute or verify EID (eUICC ID) values
+#
+# (C) 2024 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/>.
+
+import sys
+import argparse
+
+from pySim.euicc import compute_eid_checksum, verify_eid_checksum
+
+
+option_parser = argparse.ArgumentParser(formatter_class=argparse.RawDescriptionHelpFormatter,
+                                        description="""pySim EID Tool
+This utility program can be used to compute or verify the checksum of an EID
+(eUICC Identifier).  See GSMA SGP.29 for the algorithm details.
+
+Example (verification):
+    $ eidtool.py --verify 89882119900000000000000000001654
+    EID checksum verified successfully
+
+Example (generation, passing first 30 digits):
+    $ eidtool.py --compute 898821199000000000000000000016
+    89882119900000000000000000001654
+
+Example (generation, passing all 32 digits):
+    $ eidtool.py --compute 89882119900000000000000000001600
+    89882119900000000000000000001654
+
+Example (generation, specifying base 30 digits and number to add):
+    $ eidtool.py --compute 898821199000000000000000000000 --add 16
+    89882119900000000000000000001654
+""")
+group = option_parser.add_mutually_exclusive_group(required=True)
+group.add_argument('--verify', help='Verify given EID csum')
+group.add_argument('--compute', help='Generate EID csum')
+option_parser.add_argument('--add', type=int, help='Add value to EID base before computing')
+
+
+if __name__ == '__main__':
+    opts = option_parser.parse_args()
+
+    if opts.verify:
+        res = verify_eid_checksum(opts.verify)
+        if res:
+            print("EID checksum verified successfully")
+            sys.exit(0)
+        else:
+            print("EID checksum invalid")
+            sys.exit(1)
+    elif opts.compute:
+        eid = opts.compute
+        if opts.add:
+            if len(eid) != 30:
+                print("EID base must be 30 digits when using --add")
+                sys.exit(2)
+            eid = str(int(eid) + int(opts.add))
+        res = compute_eid_checksum(eid)
+        print(res)
+

