Commit Graph

13 Commits

Author SHA1 Message Date
Harald Welte ba955b650e pySim/tlv.py: Don't create an exception from within raise
An invalid variable used in a raise ValueError() would cause a further
exception, depriving the user of a meaningful error message.

Change-Id: I6eb31b91bd69c311f07ff259a424edc58b57529a
2023-07-11 08:42:12 +02:00
Harald Welte 30de9fd8ab TLV_IE_Collection: use snake-style names during from_dict()
The TLV_IE_Collection, just like the individual TLV classes, do
use their snake-style names when converting from binary to dict
using the to_dict() method.  It is inconsistent (and a bug) to
expect the CamelCase names during encoding (from_dict).  After all,
we want the output of to_dict() to be used as input to from_dict().

Change-Id: Iabd1ad98c3878659d123eef919c22ca824886f8a
2023-07-11 08:42:12 +02:00
Harald Welte 579ac3ec0e tlv: Fix IE.from_dict() method
The existing IE.from_dict() method *supposedly* accepts a dict as
input value, but it actually expects the raw decoded value, unless it is
a nested IE.  This is inconsistent in various ways, and results in a bug
visible at a higher layer, such as files like EF.{DOMAIN,IMPI,IMPU},
which are transparent files containing a single BER-TLV IE.

Decoding such files worked, but re-encoding them did not, due to the
fact that we'd pass a dict to the from_dict method, which then gets
assigned to self.decoded and further passed along to any later actual
encoder function like to_bytes or to_tlv.  In that instance, the dict
might be handed to a self._construct which has no idea how to process
the dict, as it expects the raw decoded value.

Change-Id: I3dd5204510e5c32ef1c4a999258d87cb3f1df8c8
Closes: OS#6073
Related: OS#6072
2023-06-27 09:29:37 +02:00
Harald Welte 7d8029eb23 tlv: Use self._compute_tag() method rather than direct self.tag
The TLV_IE.from_tlv() method is part of a base class that is inherited
by more specific classes.  The official way to obtain the tag is the
inherited-class-provided self._compute_tag() method, and *not* a direct
reference to the self.tag member.

This allows for some more obscure TLV parsers, such as the upcoming one
for Proactive Commands in the CAT/OTA context.

Change-Id: I0cd70e31567edc5a0584336efcb5e4282734f6dd
2022-08-06 13:19:16 +02:00
Harald Welte ea600a8451 tlv: Make NotImplementedError more verbose
This helps to understand immediately _what_ is not implemented for which
type.

Change-Id: I017eb4828e9deee80338024c41c93c0f78db3f3b
2022-07-20 19:35:58 +02:00
Harald Welte e4a6eafc6f tlv: Don't raise exception if somebody passes empty data to TLV decoder
Change-Id: Id46994029d9b3cd6b67f4f7ee619466602cc8142
2022-02-14 00:44:55 +01:00
Harald Welte e8d177d88f tlv: Convert CamelCase class name to snake_case in json
Our hand-written JSON so far is using snake_case identifiers,
while the JSON generated by the pySim.tlv classes use the class
names as keys, which LooksQuiteDifferent.

So let's auto-convert the CamelCase into something that reflects
our existing notion.

Change-Id: Id55929ef03dc48cb668e6ba7e99b6b291680a42f
2022-02-12 08:33:37 +00:00
Harald Welte 9a2a6691b0 tlv: Function for flattening the list-of-dict output of TLV decoder
Before:
{
    "FcpTemplate": [
        {
            "FileDescriptor": {
                "shareable": true,
                "file_type": "df",
                "structure": "no_info_given"
            }
        },
        {
            "FileIdentifier": "3f00"
        },
        {
            "ProprietaryInformation": [
                {
                    "UiccCharacteristics": "71"
                },
                {
                    "AvailableMemory": 123052
                }
            ]
        },
        {
            "LifeCycleStatusInteger": "operational_activated"
        },
        {
            "SecurityAttribReferenced": {
                "ef_arr_file_id": "2f06",
                "ef_arr_record_nr": 2
            }
        },
        {
            "PinStatusTemplate_DO": [
                {
                    "PS_DO": "40"
                },
                {
                    "KeyReference": 1
                },
                {
                    "KeyReference": 129
                }
            ]
        },
        {
            "TotalFileSize": 187809
        }
    ]
}

After:
{
    "FcpTemplate": {
        "FileDescriptor": {
            "shareable": true,
            "file_type": "df",
            "structure": "no_info_given"
        },
        "FileIdentifier": "3f00",
        "ProprietaryInformation": {
            "UiccCharacteristics": "71",
            "AvailableMemory": 123052
        },
        "LifeCycleStatusInteger": "operational_activated",
        "SecurityAttribReferenced": {
            "ef_arr_file_id": "2f06",
            "ef_arr_record_nr": 2
        },
        "PinStatusTemplate_DO": {
            "PS_DO": "40",
            "KeyReference": 129
        },
        "TotalFileSize": 187809
    }
}

Change-Id: Ia5ad8f1d3b0d47ebdb1856b0feaba120bad3eef9
2022-02-11 17:13:01 +01:00
Harald Welte c91085e744 cosmetic: Switch to consistent four-spaces indent; run autopep8
We had a mixture of tab and 4space based indenting, which is a bad
idea.  4space is the standard in python, so convert all our code to
that.  The result unfortuantely still shoed even more inconsistencies,
so I've decided to run autopep8 on the entire code base.

Change-Id: I4a4b1b444a2f43fab05fc5d2c8a7dd6ddecb5f07
2022-02-11 13:32:58 +01:00
Harald Welte 5895380a45 tlv: Fix recursive initialization from_dict()
When calling from_dict() on a hierarchy of nested BER_TLV_IE,
only the first/outer layer of TLV_IE_Collection would get its
'decoded' initialized correctly from the dict.  Subsequent layers
were not, as the 'decoded=' was passed as parameter during instance
initialization.  If we first instantiate the class and then call the
from_dict() method, the recursive initialization down the full hierarchy
works as expected.

Change-Id: I795a33ed8dfa8454dc9079c189ab7b2ba64a3b72
2021-10-21 14:12:13 +02:00
Harald Welte 04c1302b68 tlv: Don't require encoder/decoder methods for TLV without value
There are instances where a TLV IE is used as just a flag, i.e.
length zero and no value part.  In those situations, it would require
a lot of boilerplate code to require the TLV_IE class definitions to
have _to_bytes/_from_bytes methods that do nothing.

So instead, add a shortcut: If we want to encode 'None', then return
b'', and if we want to decode b'' return None.

Change-Id: Ie8eb2830e8eefa81e94b8b8b157062c085aeb777
2021-10-21 14:12:13 +02:00
Harald Welte fb50621570 filesystem: Introduce support for TLV parser
This adds an easy way for files to make use of the pySim.tlv parser.

All a file has to do is to specify a _tlv member which points to
either a TLV_IE or a TLV_IE_Collection instance.

Change-Id: I59f456b4223ec88081e91cee168b654c69bcb5f4
2021-06-05 10:47:17 +02:00
Harald Welte bb3b5df8bf Introduce new object-oriented TLV parser/decoder/encoder
This introduces a new TLV library that heavily builds upon python object
oriented concepts.  Contrary to classic TLV parsers it doesn't focus on
the structure of Tag, Length and binary Value only, but it supports
actual decoding/interpretation of the value part into some kind of JSON
serializable dict.  The latter can be achieved by imperative
encode/decode methods, or by using our existing declarative 'construct'
based approach.

The TLV library supports both BER-TLV and COMPREHENSION-TLV for both
nested and non-nested TLV definitions.

As an example we include TLV definitions for a number of CAT (Card
Application Toolkit) IEs.

Change-Id: I7fc1699443bc9d8a4e7cdd2687af9af7cc03c30e
2021-06-05 10:47:17 +02:00