Change in pysim[master]: commands: add ".." notation to expand hexstrings

dexter has uploaded this change for review. ( https://gerrit.osmocom.org/c/pysim/+/28218 ) Change subject: commands: add ".." notation to expand hexstrings ...................................................................... commands: add ".." notation to expand hexstrings When updating files and records there are sometimes huge portions that are just 0xff. Mostly this is at the end of a file or record that is not completely used. Lets add a notation to tell PySim-shell how to fill those sections. Change-Id: Iedd7887bf7d706878f4a3beca8dbea456404610b --- M pySim/commands.py M pySim/utils.py 2 files changed, 64 insertions(+), 5 deletions(-) git pull ssh://gerrit.osmocom.org:29418/pysim refs/changes/18/28218/1 diff --git a/pySim/commands.py b/pySim/commands.py index a959851..7b50677 100644 --- a/pySim/commands.py +++ b/pySim/commands.py @@ -23,7 +23,7 @@ from construct import * from pySim.construct import LV -from pySim.utils import rpad, b2h, h2b, sw_match, bertlv_encode_len, Hexstr, h2i, str_sanitize +from pySim.utils import rpad, b2h, h2b, sw_match, bertlv_encode_len, Hexstr, h2i, str_sanitize, expand_hex from pySim.exceptions import SwMatchError @@ -190,6 +190,10 @@ offset : byte offset in file from which to start writing verify : Whether or not to verify data after write """ + + file_len = self.binary_size(ef) + data = expand_hex(data, file_len) + data_length = len(data) // 2 # Save write cycles by reading+comparing before write @@ -255,16 +259,17 @@ verify : verify data by re-reading the record conserve : read record and compare it with data, skip write on match """ + res = self.select_path(ef) + rec_length = self.__record_len(res) + data = expand_hex(data, rec_length) if force_len: # enforce the record length by the actual length of the given data input rec_length = len(data) // 2 else: - # determine the record length from the select response of the file and pad - # the input data with 0xFF if necessary. In cases where the input data - # exceed we throw an exception. - rec_length = self.__record_len(res) + # make sure the input data is padded to the record length using 0xFF. + # In cases where the input data exceed we throw an exception. if (len(data) // 2 > rec_length): raise ValueError('Data length exceeds record length (expected max %d, got %d)' % ( rec_length, len(data) // 2)) diff --git a/pySim/utils.py b/pySim/utils.py index ef770f9..6b8ee37 100644 --- a/pySim/utils.py +++ b/pySim/utils.py @@ -1225,6 +1225,60 @@ return int(x, 0) +def expand_hex(hexstring, length): + """Expand a given hexstring to a specified length by replacing "." or ".." + with a filler that is derived from the neighboring nibbles respective + bytes. Usually this will be the nibble respective byte before "." or + "..", execpt when the string begins with "." or "..", then the nibble + respective byte after "." or ".." is used.". In case the string cannot + be expanded for some reason, the input string is returned unmodified. + + Args: + hexstring : hexstring to expand + length : desired length of the resulting hexstring. + Returns: + expanded hexstring + """ + + # expand digit aligned + if hexstring.count(".") == 1: + pos = hexstring.index(".") + if pos > 0: + filler = hexstring[pos - 1] + else: + filler = hexstring[pos + 1] + + missing = length * 2 - (len(hexstring) - 1) + if missing <= 0: + return hexstring + + return hexstring.replace(".", filler * missing) + + # expand byte aligned + elif hexstring.count("..") == 1: + if len(hexstring) % 2: + return hexstring + + pos = hexstring.index("..") + + if pos % 2: + return hexstring + + if pos > 1: + filler = hexstring[pos - 2:pos] + else: + filler = hexstring[pos + 2:pos+4] + + missing = length * 2 - (len(hexstring) - 2) + if missing <= 0: + return hexstring + + return hexstring.replace("..", filler * (missing // 2)) + + # no change + return hexstring + + class JsonEncoder(json.JSONEncoder): """Extend the standard library JSONEncoder with support for more types.""" -- To view, visit https://gerrit.osmocom.org/c/pysim/+/28218 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: pysim Gerrit-Branch: master Gerrit-Change-Id: Iedd7887bf7d706878f4a3beca8dbea456404610b Gerrit-Change-Number: 28218 Gerrit-PatchSet: 1 Gerrit-Owner: dexter &lt;pmaier(a)sysmocom.de&gt; Gerrit-MessageType: newchange