dexter has uploaded this change for review.
javacard: add parser for JAVA-card CAP file format
To install JAVA-card applets we need to be able to extract the executeable
loadfile and the AIDs of the applet and the loadfile. This patch adds the
parser and related unittests.
Related: OS#6679
Change-Id: I581483ccb9d8a254fcecc995fec3c811c5cf38eb
---
M pySim/javacard.py
A tests/unittests/test_javacard.cap
A tests/unittests/test_javacard.py
3 files changed, 173 insertions(+), 1 deletion(-)
git pull ssh://gerrit.osmocom.org:29418/pysim refs/changes/98/39198/1
diff --git a/pySim/javacard.py b/pySim/javacard.py
index 07b0f39..c304999 100644
--- a/pySim/javacard.py
+++ b/pySim/javacard.py
@@ -1,9 +1,30 @@
# JavaCard related utilities
-
+#
+# (C) 2024 by Sysmocom s.f.m.c. GmbH
+# All Rights Reserved
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
import zipfile
import struct
import sys
import io
+from osmocom.utils import b2h
+from construct import Struct, Array, this, Int32ub, Int16ub, Int8ub
+from osmocom.construct import *
+from osmocom.tlv import *
+from construct import Optional as COptional
def ijc_to_cap(in_file: io.IOBase, out_zip: zipfile.ZipFile, p : str = "foo"):
"""Convert an ICJ (Interoperable Java Card) file [back] to a CAP file.
@@ -19,3 +40,136 @@
out_zip.writestr(p+"/javacard/"+TAGS[tag-1]+".cap", b[0:3+size])
b = b[3+size:]
+class CapFile():
+
+ #TODO: At the moment we only support the compact .cap format, add support for the extended .cap format.
+
+ __component_header = None
+ __component_directory = None
+ __component_applet = None #optional
+ __component_import = None
+ __component_constantPool = None
+ __component_class = None
+ __component_method = None
+ __component_staticField = None
+ __component_referenceLocation = None
+ __component_export = None #optional
+ __component_descriptor = None
+ __component_debug = None #optional, since CAP format 2.2
+
+ # Java Card Platform Virtual Machine Specification, v3.2, section 6.4
+ __header_component_compact = Struct('tag'/Int8ub,
+ 'size'/Int16ub,
+ 'magic'/Int32ub,
+ 'minor_version'/Int8ub,
+ 'major_version'/Int8ub,
+ 'flags'/Int8ub,
+ 'package'/Struct('minor_version'/Int8ub,
+ 'major_version'/Int8ub,
+ 'AID'/LV),
+ 'package_name'/COptional(LV)) #since CAP format 2.2
+
+ # Java Card Platform Virtual Machine Specification, v3.2, section 6.6
+ __applet_component_compact = Struct('tag'/Int8ub,
+ 'size'/Int16ub,
+ 'count'/Int8ub,
+ 'applets'/Array(this.count, Struct('AID'/LV,
+ 'install_method_offset'/Int16ub)),
+ )
+
+ def __init__(self, filename:str):
+ # Extract the nested .cap components from the .cap file
+ # See also: Java Card Platform Virtual Machine Specification, v3.2, section 6.2.1
+ cap = zipfile.ZipFile(filename)
+ cap_namelist = cap.namelist()
+ for i, filename in enumerate(cap_namelist):
+ if filename.lower().endswith('header.cap'):
+ self.__component_header = cap.read(filename)
+ elif filename.lower().endswith('directory.cap'):
+ self.__component_directory = cap.read(filename)
+ elif filename.lower().endswith('applet.cap'):
+ self.__component_applet = cap.read(filename)
+ elif filename.lower().endswith('import.cap'):
+ self.__component_import = cap.read(filename)
+ elif filename.lower().endswith('constantpool.cap'):
+ self.__component_constantPool = cap.read(filename)
+ elif filename.lower().endswith('class.cap'):
+ self.__component_class = cap.read(filename)
+ elif filename.lower().endswith('method.cap'):
+ self.__component_method = cap.read(filename)
+ elif filename.lower().endswith('staticfield.cap'):
+ self.__component_staticField = cap.read(filename)
+ elif filename.lower().endswith('reflocation.cap'):
+ self.__component_referenceLocation = cap.read(filename)
+ elif filename.lower().endswith('export.cap'):
+ self.__component_export = cap.read(filename)
+ elif filename.lower().endswith('descriptor.cap'):
+ self.__component_descriptor = cap.read(filename)
+ elif filename.lower().endswith('debug.cap'):
+ self.__component_debug = cap.read(filename)
+
+ # Make sure that all mandatory components are present
+ # See also: Java Card Platform Virtual Machine Specification, v3.2, section 6.2
+ if self.__component_header is None:
+ raise ValueError("invalid cap file, COMPONENT_Header missing!")
+ if self.__component_directory is None:
+ raise ValueError("invalid cap file, COMPONENT_Directory missing!")
+ if self.__component_import is None:
+ raise ValueError("invalid cap file, COMPONENT_Import missing!")
+ if self.__component_constantPool is None:
+ raise ValueError("invalid cap file, COMPONENT_ConstantPool missing!")
+ if self.__component_class is None:
+ raise ValueError("invalid cap file, COMPONENT_Class missing!")
+ if self.__component_method is None:
+ raise ValueError("invalid cap file, COMPONENT_Method missing!")
+ if self.__component_staticField is None:
+ raise ValueError("invalid cap file, COMPONENT_StaticField missing!")
+ if self.__component_referenceLocation is None:
+ raise ValueError("invalid cap file, COMPONENT_ReferenceLocation missing!")
+ if self.__component_descriptor is None:
+ raise ValueError("invalid cap file, COMPONENT_Descriptor missing!")
+
+ def get_loadfile(self):
+ """Get the executeable loadfile as hexstring"""
+ # Concatenate all cap file components in the specified order
+ # see also: Java Card Platform Virtual Machine Specification, v3.2, section 6.3
+ loadfile = self.__component_header
+ loadfile += self.__component_directory
+ loadfile += self.__component_import
+ if self.__component_applet:
+ loadfile += self.__component_applet
+ loadfile += self.__component_class
+ loadfile += self.__component_method
+ loadfile += self.__component_staticField
+ if self.__component_export:
+ loadfile += self.__component_export
+ loadfile += self.__component_constantPool
+ loadfile += self.__component_referenceLocation
+ if self.__component_descriptor:
+ loadfile += self.__component_descriptor
+ return b2h(loadfile)
+
+ def get_loadfile_aid(self):
+ """Get the loadfile AID as hexstring"""
+ header = self.__header_component_compact.parse(self.__component_header)
+ magic = header['magic'] or 0
+ if magic != 0xDECAFFED:
+ raise ValueError("invalid cap file, COMPONENT_Header lacks magic number (0x%08X!=0xDECAFFED)!" % magic)
+ #TODO: check cap version and make sure we are compatible with it
+ return header['package']['AID']
+
+ def get_applet_aid(self, index:int = 0):
+ """Get the applet AID as hexstring"""
+ #To get the module AID, we must look into COMPONENT_Applet. Unfortunately, even though this component should
+ #be present in any .cap file, it is defined as an optional component.
+ if self.__component_applet is None:
+ raise ValueError("can't get the AID, this cap file lacks the optional COMPONENT_Applet component!")
+
+ applet = self.__applet_component_compact.parse(self.__component_applet)
+
+ if index > applet['count']:
+ raise ValueError("can't get the AID for applet with index=%u, this .cap file only has %u applets!" %
+ (index, applet['count']))
+
+ return applet['applets'][index]['AID']
+
diff --git a/tests/unittests/test_javacard.cap b/tests/unittests/test_javacard.cap
new file mode 100644
index 0000000..f96ea24
--- /dev/null
+++ b/tests/unittests/test_javacard.cap
Binary files differ
diff --git a/tests/unittests/test_javacard.py b/tests/unittests/test_javacard.py
new file mode 100755
index 0000000..30d8bdd
--- /dev/null
+++ b/tests/unittests/test_javacard.py
@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+
+import os
+import unittest
+from pySim.javacard import *
+
+class TestJavacard(unittest.TestCase):
+
+ def test_CapFile(self):
+ loadfile="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"
+ cap = CapFile(os.path.dirname(os.path.abspath(__file__)) + "/test_javacard.cap")
+ self.assertTrue(cap.get_loadfile() == loadfile)
+ self.assertTrue(cap.get_loadfile_aid() == "d07002ca44")
+ self.assertTrue(cap.get_applet_aid() == "d07002ca44900101")
+
+
+if __name__ == "__main__":
+ unittest.main()
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