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P1sec
customizing to_asn1 output
Hi
I would like to know the best way to change the look of to_asn1 output for various objects. I tried to modify the code in pycrate_asn1/asnobj.py. Let us take an example
Say I want to print the TIME_UTC output as YYMMDDHHMMSSUTC instead of YYMMDDHHMMSSZ.
Is it enough to modify TIME_UTC code ? Do we need to re-build package afterwards ?
class TIME_UTC(_Time): doc = """ ASN.1 basic type UTCTime object
single value: Python 7-tuple of int (AA, MM, DD, HH, MM, [SS,] Z),
SS is optional, hence 6th element can be None
Z corresponds to the UTC decay
%s
""" % ASN1Obj_docstring
TYPE = TYPE_TIME_UTC
TAG = 23
_type = TYPE
def _to_asn1(self, val):
# to be applied to an internal single value `val' to get
# an ASN.1 compliant value
ret = '%.2i%.2i%.2i%.2i%.2i' % val[:5]
if val[5] is not None:
ret += '%.2i' % val[5]
if val[6] == 0:
ret += 'Z'
elif val[6] > 0:
ret += '+%.4i' % val[6]
else:
ret += '%.4i' % val[6]
return ret
Thank you in advance
As soon as you patch a file of the library, the change will be effective as soon as you load it (e.g. in case you use only a local version from your $HOME, or you installed with setup.py install develop): no need for re-packaging. This is one of the advantage of Python.
Regarding the modification of the generic to_asn1() in asnobj.py, or the various _to_asn1() methods, this will change the formatting of the output for sure. On the other side, to_asn1() is made to produce ASN.1-compliant syntax and formatting (its output could be ingested by some other ASN.1 tools), it may not be the case anymore if you change those methods.
Thank you for your quick reply
I am trying to modify the code in pycrate_asn1rt/asnobjcontruct.py
The goal is systematically number items within a list.
def _to_asn1(self):
if not self._val:
# empty dict
return '{ }'
else:
val = []
# root and ext part in 1 shot
# WNG: we are not ordering SET root components in canonical order
for ident in self._cont:
if ident in self._val:
print ("ident = {0}".format(ident))
_par = self._cont[ident]._parent
self._cont[ident]._parent = self
self._cont[ident]._val = self._val[ident]
print (' %s %s,\n' % (ident, self._cont[ident]._to_asn1().replace('\n', '\n ')))
val.append(' %s %s,\n' % (ident, self._cont[ident]._to_asn1().replace('\n', '\n ')))
self._cont[ident]._parent = _par
if val:
val[-1] = val[-1][:-2]
return '{\n' + ''.join(val) + '\n}'
If we take the example of an NR RRC DL-DCCH message
Message = 00 0c 02 48 20 08 44 02 92 48 00 30 00 0a 24 00 18 00 02 12 42 94 0a 10 84 1c 6b 80 80 9c 08 00 00 3d 06 24 30 54 06 e0 40 00 01 e8 31 26 82 a5 05 28 14 21 08 38 d7 01 01 38 10 00 00 7a 0c 48 60 a8 0d c0 80 00 03 d0 62 4d 05 40 00
In blue, the decoding as it is right now after invoking to_asn1 method, in red what I would like to add in a systematic way, without having to delve into each message with get_at() or get_val_at() methods. Is there a simple modification of _to_asn1 that may achieve the item numbering ?
{ message c1 : rrcReconfiguration : { rrc-TransactionIdentifier 0, criticalExtensions rrcReconfiguration : { nonCriticalExtension { masterCellGroup CellGroupConfig: { cellGroupId 0, spCellConfig { spCellConfigDedicated { downlinkBWP-ToAddModList { { Item 0 bwp-Id 1, bwp-Dedicated { pdsch-Config setup : { resourceAllocation resourceAllocationType0, rbg-Size config1, mcs-Table qam256, maxNrofCodeWordsScheduledByDCI n1, prb-BundlingType staticBundling : { } } } }, { Item 1 bwp-Id 2, bwp-Dedicated { pdsch-Config setup : { resourceAllocation resourceAllocationType0, rbg-Size config1, mcs-Table qam256, maxNrofCodeWordsScheduledByDCI n1, prb-BundlingType staticBundling : { } } } } }, uplinkConfig { uplinkBWP-ToAddModList { { Item 0 bwp-Id 1, bwp-Dedicated { srs-Config setup : { srs-ResourceSetToAddModList { Item 0 { srs-ResourceSetId 2, srs-ResourceIdList { 2, 3 }, resourceType periodic : { }, usage antennaSwitching, p0 -110 } }, srs-ResourceToAddModList { { Item 0 srs-ResourceId 2, nrofSRS-Ports ports2, transmissionComb n4 : { combOffset-n4 2, cyclicShift-n4 0 }, resourceMapping { startPosition 2, nrofSymbols n1, repetitionFactor n1 }, freqDomainPosition 0, freqDomainShift 0, freqHopping { c-SRS 61, b-SRS 0, b-hop 0 }, groupOrSequenceHopping groupHopping, resourceType periodic : { periodicityAndOffset-p sl40 : 3 }, sequenceId 21 }, { Item 1 srs-ResourceId 3, nrofSRS-Ports ports2, transmissionComb n4 : { combOffset-n4 2, cyclicShift-n4 0 }, resourceMapping { startPosition 2, nrofSymbols n1, repetitionFactor n1 }, freqDomainPosition 0, freqDomainShift 0, freqHopping { c-SRS 61, b-SRS 0, b-hop 0 }, groupOrSequenceHopping groupHopping, resourceType periodic : { periodicityAndOffset-p sl40 : 13 }, sequenceId 21 } } } } }, { Item 1 bwp-Id 2, bwp-Dedicated { srs-Config setup : { srs-ResourceSetToAddModList { Item 0 { srs-ResourceSetId 2, srs-ResourceIdList { 2, 3 }, resourceType periodic : { }, usage antennaSwitching, p0 -110 } }, srs-ResourceToAddModList { { Item 0 srs-ResourceId 2, nrofSRS-Ports ports2, transmissionComb n4 : { combOffset-n4 2, cyclicShift-n4 0 }, resourceMapping { startPosition 2, nrofSymbols n1, repetitionFactor n1 }, freqDomainPosition 0, freqDomainShift 0, freqHopping { c-SRS 61, b-SRS 0, b-hop 0 }, groupOrSequenceHopping groupHopping, resourceType periodic : { periodicityAndOffset-p sl40 : 3 }, sequenceId 21 }, { Item 1 srs-ResourceId 3, nrofSRS-Ports ports2, transmissionComb n4 : { combOffset-n4 2, cyclicShift-n4 0 }, resourceMapping { startPosition 2, nrofSymbols n1, repetitionFactor n1 }, freqDomainPosition 0, freqDomainShift 0, freqHopping { c-SRS 61, b-SRS 0, b-hop 0 }, groupOrSequenceHopping groupHopping, resourceType periodic : { periodicityAndOffset-p sl40 : 13 }, sequenceId 21 } } } } } } }, tag-Id 0, servingCellMO 1 } } } } } } }
Thank you in advance
Best regards
Dominique
From: Benoit Michau @.> Sent: Monday, April 4, 2022 12:04 PM To: P1sec/pycrate @.> Cc: Dominique Bressanelli @.>; Author @.> Subject: Re: [P1sec/pycrate] customizing to_asn1 output (Issue #186)
WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.
As soon as you patch a file of the library, the change will be effective as soon as you load it (e.g. in case you use only a local version from your $HOME, or you installed with setup.py install develop): no need for re-packaging. This is one of the advantage of Python.
Regarding the modification of the generic to_asn1() in asnobj.py, or the various _to_asn1() methods, this will change the formatting of the output for sure. On the other side, to_asn1() is made to produce ASN.1-compliant syntax and formatting (its output could be ingested by some other ASN.1 tools), it may not be the case anymore if you change those methods.
— Reply to this email directly, view it on GitHubhttps://github.com/P1sec/pycrate/issues/186#issuecomment-1087357281, or unsubscribehttps://github.com/notifications/unsubscribe-auth/AHUUMPNFIK6X7AOUH6ZS2BTVDK5ANANCNFSM5SO6BQ7Q. You are receiving this because you authored the thread.Message ID: @.@.>>
I don't really understand what / how you want to number items. I see no colour in your provided description, sorry.
Hi
What I wish to add is highlighted below with the mark “<=== to be added”
{ message c1 : rrcReconfiguration : { rrc-TransactionIdentifier 0, criticalExtensions rrcReconfiguration : { nonCriticalExtension { masterCellGroup CellGroupConfig: { cellGroupId 0, spCellConfig { spCellConfigDedicated { downlinkBWP-ToAddModList { { Item 0 <=== to be added bwp-Id 1, bwp-Dedicated { pdsch-Config setup : { resourceAllocation resourceAllocationType0, rbg-Size config1, mcs-Table qam256, maxNrofCodeWordsScheduledByDCI n1, prb-BundlingType staticBundling : { } } } }, { Item 1 <=== to be added bwp-Id 2, bwp-Dedicated { pdsch-Config setup : { resourceAllocation resourceAllocationType0, rbg-Size config1, mcs-Table qam256, maxNrofCodeWordsScheduledByDCI n1, prb-BundlingType staticBundling : { } } } } }, uplinkConfig { uplinkBWP-ToAddModList { { Item 0 <=== to be added bwp-Id 1, bwp-Dedicated { srs-Config setup : { srs-ResourceSetToAddModList { Item 0 <=== to be added { srs-ResourceSetId 2, srs-ResourceIdList { 2, 3 }, resourceType periodic : { }, usage antennaSwitching, p0 -110 } }, srs-ResourceToAddModList { { Item 0 <=== to be added srs-ResourceId 2, nrofSRS-Ports ports2, transmissionComb n4 : { combOffset-n4 2, cyclicShift-n4 0 }, resourceMapping { startPosition 2, nrofSymbols n1, repetitionFactor n1 }, freqDomainPosition 0, freqDomainShift 0, freqHopping { c-SRS 61, b-SRS 0, b-hop 0 }, groupOrSequenceHopping groupHopping, resourceType periodic : { periodicityAndOffset-p sl40 : 3 }, sequenceId 21 }, { Item 1 <=== to be added srs-ResourceId 3, nrofSRS-Ports ports2, transmissionComb n4 : { combOffset-n4 2, cyclicShift-n4 0 }, resourceMapping { startPosition 2, nrofSymbols n1, repetitionFactor n1 }, freqDomainPosition 0, freqDomainShift 0, freqHopping { c-SRS 61, b-SRS 0, b-hop 0 }, groupOrSequenceHopping groupHopping, resourceType periodic : { periodicityAndOffset-p sl40 : 13 }, sequenceId 21 } } } } }, { Item 1 <=== to be added bwp-Id 2, bwp-Dedicated { srs-Config setup : { srs-ResourceSetToAddModList { Item 0 <=== to be added { srs-ResourceSetId 2, srs-ResourceIdList { 2, 3 }, resourceType periodic : { }, usage antennaSwitching, p0 -110 } }, srs-ResourceToAddModList { { Item 0 <=== to be added srs-ResourceId 2, nrofSRS-Ports ports2, transmissionComb n4 : { combOffset-n4 2, cyclicShift-n4 0 }, resourceMapping { startPosition 2, nrofSymbols n1, repetitionFactor n1 }, freqDomainPosition 0, freqDomainShift 0, freqHopping { c-SRS 61, b-SRS 0, b-hop 0 }, groupOrSequenceHopping groupHopping, resourceType periodic : { periodicityAndOffset-p sl40 : 3 }, sequenceId 21 }, { Item 1 <=== to be added srs-ResourceId 3, nrofSRS-Ports ports2, transmissionComb n4 : { combOffset-n4 2, cyclicShift-n4 0 }, resourceMapping { startPosition 2, nrofSymbols n1, repetitionFactor n1 }, freqDomainPosition 0, freqDomainShift 0, freqHopping { c-SRS 61, b-SRS 0, b-hop 0 }, groupOrSequenceHopping groupHopping, resourceType periodic : { periodicityAndOffset-p sl40 : 13 }, sequenceId 21 } } } } } } }, tag-Id 0, servingCellMO 1 } } } } } } }
Thank you very much for your help
Best regards
Dominique
From: Benoit Michau @.> Sent: Monday, April 11, 2022 9:54 AM To: P1sec/pycrate @.> Cc: Dominique Bressanelli @.>; Author @.> Subject: Re: [P1sec/pycrate] customizing to_asn1 output (Issue #186)
WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.
I don't really understand what / how you want to number items. I see no colour in your provided description, sorry.
— Reply to this email directly, view it on GitHubhttps://github.com/P1sec/pycrate/issues/186#issuecomment-1094669380, or unsubscribehttps://github.com/notifications/unsubscribe-auth/AHUUMPKSQUWGMWTRFLFGYBLVEPLB5ANCNFSM5SO6BQ7Q. You are receiving this because you authored the thread.Message ID: @.@.>>
You can modify the _to_asn1() method of the _CONSTRUCT_OF class here: https://github.com/P1sec/pycrate/blob/1a6d4d6ab8b61e0ef4ea9314ac07facfdd10f785/pycrate_asn1rt/asnobj_construct.py#L2686
To have a pattern like this instead:
for i, v in enumerate(self._val):
self._cont._val = v
val.append(' -- _item_ %i --\n %s,\n' % (i, self._cont._to_asn1().replace('\n', '\n ')))
I guess such generated ASN.1 syntax won't be re-encodable with pycrate, as its runtime does not strip ASN.1 comments out.
Thank you so much, this is exactly what I was looking for.
Yes, I understand the limitation about the ASN.1 syntax not being re-encodable. However this is not blocking to me
Best regards
Dominique
From: Benoit Michau @.> Sent: Tuesday, April 26, 2022 3:05 PM To: P1sec/pycrate @.> Cc: Dominique Bressanelli @.>; Author @.> Subject: Re: [P1sec/pycrate] customizing to_asn1 output (Issue #186)
WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.
You can modify the _to_asn1() method of the _CONSTRUCT_OF class here: https://github.com/P1sec/pycrate/blob/1a6d4d6ab8b61e0ef4ea9314ac07facfdd10f785/pycrate_asn1rt/asnobj_construct.py#L2686 To have a pattern like this instead:
for i, v in enumerate(self._val):
self._cont._val = v
val.append(' -- _item_ %i --\n %s,\n' % (i, self._cont._to_asn1().replace('\n', '\n ')))
I guess such generated ASN.1 syntax won't be re-encodable with pycrate, as its runtime does not strip ASN.1 comments out.
— Reply to this email directly, view it on GitHubhttps://github.com/P1sec/pycrate/issues/186#issuecomment-1109772794, or unsubscribehttps://github.com/notifications/unsubscribe-auth/AHUUMPK2ORIFZB4IJZKQIX3VG7SZHANCNFSM5SO6BQ7Q. You are receiving this because you authored the thread.Message ID: @.@.>>