[S] Change in pysim[master]: filesystem: add attribute "leftpad" to class LinFixedEF

dexter has uploaded this change for review. ( https://gerrit.osmocom.org/c/pysim/+/34336?usp=email ) Change subject: filesystem: add attribute "leftpad" to class LinFixedEF ...................................................................... filesystem: add attribute "leftpad" to class LinFixedEF In some cases, the specs do not specify an absolute record length. Instead there may be only a minimum record length specified. The card vendor may then chose to use larger record length at will. This usually is no problem since the data is usually written from the left and the remaining bytes are padded at the end (right side) of the data. However in some rare cases (EF.MSISDN, see also 3GPP TS 51.011, section 10.5.5) the data must be written right-aligned towards the physical record length. This means that the data is padded from the left in this case. To fix this: Let's add a "leftpad" flag to LinFixedEF, which we set to true in those corner cases. The code that updates the record in commands.py must then check this flag and padd the data accordingly. Change-Id: I241d9fd656f9064a3ebb4e8e01a52b6b030f9923 Related: OS#5714 --- M pySim/commands.py M pySim/filesystem.py M pySim/runtime.py M pySim/ts_51_011.py 4 files changed, 38 insertions(+), 8 deletions(-) git pull ssh://gerrit.osmocom.org:29418/pysim refs/changes/36/34336/1 diff --git a/pySim/commands.py b/pySim/commands.py index 477cb2b..e072069 100644 --- a/pySim/commands.py +++ b/pySim/commands.py @@ -26,7 +26,7 @@ from construct import * from pySim.construct import LV -from pySim.utils import rpad, b2h, h2b, sw_match, bertlv_encode_len, Hexstr, h2i, str_sanitize, expand_hex +from pySim.utils import rpad, lpad, b2h, h2b, sw_match, bertlv_encode_len, Hexstr, h2i, str_sanitize, expand_hex from pySim.utils import Hexstr, SwHexstr, ResTuple from pySim.exceptions import SwMatchError from pySim.transport import LinkBase @@ -269,7 +269,7 @@ data.lower(), res[0].lower())) def update_record(self, ef: Path, rec_no: int, data: Hexstr, force_len: bool = False, - verify: bool = False, conserve: bool = False) -> ResTuple: + verify: bool = False, conserve: bool = False, leftpad: bool = False) -> ResTuple: """Execute UPDATE RECORD. Args: @@ -279,6 +279,7 @@ force_len : enforce record length by using the actual data length verify : verify data by re-reading the record conserve : read record and compare it with data, skip write on match + leftpad : apply 0xff padding from the left instead from the right side. """ res = self.select_path(ef) @@ -295,7 +296,10 @@ raise ValueError('Data length exceeds record length (expected max %d, got %d)' % ( rec_length, len(data) // 2)) elif (len(data) // 2 < rec_length): - data = rpad(data, rec_length * 2) + if leftpad: + data = lpad(data, rec_length * 2) + else: + data = rpad(data, rec_length * 2) # Save write cycles by reading+comparing before write if conserve: diff --git a/pySim/filesystem.py b/pySim/filesystem.py index 9f3ee17..5950ad1 100644 --- a/pySim/filesystem.py +++ b/pySim/filesystem.py @@ -920,7 +920,7 @@ self._cmd.poutput_json(data) def __init__(self, fid: str, sfid: str = None, name: str = None, desc: str = None, - parent: Optional[CardDF] = None, rec_len: Size = (1, None), **kwargs): + parent: Optional[CardDF] = None, rec_len: Size = (1, None), leftpad: bool = False, **kwargs): """ Args: fid : File Identifier (4 hex digits) @@ -929,9 +929,11 @@ desc : Description of the file parent : Parent CardFile object within filesystem hierarchy rec_len : Tuple of (minimum_length, recommended_length) + leftpad: On write, data must be padded from the left to fit pysical record length """ super().__init__(fid=fid, sfid=sfid, name=name, desc=desc, parent=parent, **kwargs) self.rec_len = rec_len + self.leftpad = leftpad self.shell_commands = [self.ShellCommands()] self._construct = None self._tlv = None diff --git a/pySim/runtime.py b/pySim/runtime.py index 422e916..d6c6d19 100644 --- a/pySim/runtime.py +++ b/pySim/runtime.py @@ -458,7 +458,9 @@ """ if not isinstance(self.selected_file, LinFixedEF): raise TypeError("Only works with Linear Fixed EF") - return self.rs.card._scc.update_record(self.selected_file.fid, rec_nr, data_hex, conserve=self.rs.conserve_write) + return self.rs.card._scc.update_record(self.selected_file.fid, rec_nr, data_hex, + conserve=self.rs.conserve_write, + leftpad=self.selected_file.leftpad) def update_record_dec(self, rec_nr: int, data: dict): """Update a record with given abstract data. Will encode abstract to binary data diff --git a/pySim/ts_51_011.py b/pySim/ts_51_011.py index c81bfdf..d8cbabd 100644 --- a/pySim/ts_51_011.py +++ b/pySim/ts_51_011.py @@ -181,7 +181,7 @@ # TS 51.011 Section 10.5.5 class EF_MSISDN(LinFixedEF): def __init__(self, fid='6f40', sfid=None, name='EF.MSISDN', desc='MSISDN', **kwargs): - super().__init__(fid, sfid=sfid, name=name, desc=desc, rec_len=(15, 34), **kwargs) + super().__init__(fid, sfid=sfid, name=name, desc=desc, rec_len=(15, 34), leftpad=True, **kwargs) def _decode_record_hex(self, raw_hex_data, **kwargs): return {'msisdn': dec_msisdn(raw_hex_data)} @@ -192,8 +192,7 @@ encoded_msisdn = enc_msisdn(msisdn) else: encoded_msisdn = enc_msisdn(msisdn[2], msisdn[0], msisdn[1]) - alpha_identifier = (list(self.rec_len)[ - 0] - len(encoded_msisdn) // 2) * "ff" + alpha_identifier = (list(self.rec_len)[0] - len(encoded_msisdn) // 2) * "ff" return alpha_identifier + encoded_msisdn # TS 51.011 Section 10.5.6 -- To view, visit https://gerrit.osmocom.org/c/pysim/+/34336?usp=email To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: pysim Gerrit-Branch: master Gerrit-Change-Id: I241d9fd656f9064a3ebb4e8e01a52b6b030f9923 Gerrit-Change-Number: 34336 Gerrit-PatchSet: 1 Gerrit-Owner: dexter &lt;pmaier(a)sysmocom.de&gt; Gerrit-MessageType: newchange