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Feature #4963

Implement an interactive pysim-shell

Added by laforge about 1 month ago.

Status:
In Progress
Priority:
Normal
Assignee:
Target version:
-
Start date:
01/20/2021
Due date:
% Done:

30%

Spec Reference:

Description

pySim-prog was nice when there were only 5 parameters on a SIM that we could program, and where the use case was pretty limited. Today, we have SIM/USIM/ISIM cards with hundreds of files and even more parameters to program. We cannot add a command line argument for each file to pySim-prog.

Instead, this introduces an interactive command-line shell / REPL, in which one can navigate the file system of the card, read and update files both in raw format and in decoded/parsed format.

The idea is primarily inspired by Henryk Ploetz' venerable cyberflex-shell, but implemented on a more modern basis using the cmd2 python module.

You can see the very first prototype in the laforge/shell branch of pysim.git

You can do things with it like this:

Start-up and authenticate with adm pin

$ ./pysim-shell.py -p 0
Using PC/SC reader interface
Autodetected card type: sysmoISIM-SJA2
AIDs on card: ['a0000000871002ffffffff8907090000', 'a0000000871004ffffffff8907090000']
Welcome to pySim-shell!
pySIM-shell (3f00)> verify_adm 92990895

interactive help

pySIM-shell (3f00)> help

Documented commands (use 'help -v' for verbose/'help <topic>' for details):

ISO7816 Commands
================
read_binary  select_adf  select_file  update_binary  update_record  verify_chv

pySim Commands
==============
intro  verify_adm

USIM Commands
=============
read_ehplmn  ust_service_activate  ust_service_deactivate

pySim-shell built-in commands
=============================
alias  help     macro  quit          run_script  shell
edit   history  py     run_pyscript  set         shortcuts

more interactive help

pySIM-shell (3f00)> help read_binary
usage: read_binary [-h] [--file-id FILE_ID] [--offset OFFSET] [--length LENGTH] [--record-nr RECORD_NR]

Read binary data from a transparent EF

optional arguments:
  -h, --help            show this help message and exit
  --file-id FILE_ID     File ID
  --offset OFFSET       Byte offset for start of read
  --length LENGTH       Number of bytes to read
  --record-nr RECORD_NR
                        Number of record to read

navigating the FS and reading files

pySIM-shell (3f00)> select_file 7f20
['622c8202782183027f20a509800171830400018d088a01058b032f0601c60f90017083010183018183010a83010b']
pySIM-shell (3f00/7f20)> read_binary --file-id 6f07
089910070000400310

interaction with local filesystem, i.e. I/O redirect + shell commands

pySIM-shell (3f00)> select_adf a0000000871002
pySIM-shell (a0000000871002)> select_file 5f3b
pySIM-shell (a0000000871002/5f3b)> read_binary --file-id 4f20 > /tmp/f
pySIM-shell (a0000000871002/5f3b)> !cat /tmp/f
ffffffffffffffff07

piping output through shell tools like grep

pySIM-shell (3f00)> read_ust  | grep 86
        Service 86 - Allowed CSG Lists and corresponding indications

enabling/disabling services

pySIM-shell (3f00/7f20)> ust_service_activate 123
pySIM-shell (3f00/7f20)> ust_service_deactivate 123

The major tasks I see to make this go anywhere is:

  • have "File" class with encoder/decoder methods, which are registered automatically with a 'file system' layer that knows about the DF/ADF hierarchy
    • this allows us to have a "read-decoded" command, which will call the decode method of the file, automatically resolved by the selected FID/path
  • automatic mapping of file-name -> FID and FID -> file name
    • when printing (like in the path), use the human-readable names
    • allow users to use human-readable names in SELECT
  • decode + display the TLVs / FCPs after a SELECT (like cyberflex-shell
  • ability to enable/disable APDU trace
  • dynamically register/deregster commands based on the path, i.e. offer USIM commands only when in ADF_USIM

Related issues

Related to pySim - Bug #4962: add setup.py to pySimNew01/20/2021

History

#1 Updated by laforge about 1 month ago

  • Related to Bug #4962: add setup.py to pySim added

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