laforge has submitted this change. (
https://gerrit.osmocom.org/c/pysim/+/39225?usp=email )
Change subject: global_platform: fix usage of the Key Version Number (kvn)
......................................................................
global_platform: fix usage of the Key Version Number (kvn)
The kvn parameter is used to select a keyset when establishin a secure channel.
At the moment this is a mandatory parameter and it must be within a certain
range.
However GPC_SPE_034 explicitly defines a reserved kvn value 0, that always
refers to the first available key. That effectively makes it an optional
parameter and the commandline interface should have the --key-ver parameter
as an optional parameter.
The ranges also have to be extended to allow 0 as kvn value. We also have to
put a range to support the sysmoUSIM-SJS1, which uses kvn value 1, which is
a non standard value.
Related: OS#6679
Change-Id: I42be2438c7f199b238f2ec7a9434cec5393210a7
---
M pySim/global_platform/__init__.py
M pySim/global_platform/scp.py
2 files changed, 40 insertions(+), 5 deletions(-)
Approvals:
Jenkins Builder: Verified
fixeria: Looks good to me, but someone else must approve
laforge: Looks good to me, approved
diff --git a/pySim/global_platform/__init__.py
b/pySim/global_platform/__init__.py
index c0607ae..f2bec81 100644
--- a/pySim/global_platform/__init__.py
+++ b/pySim/global_platform/__init__.py
@@ -795,7 +795,7 @@
return self._cmd.lchan.scc.send_apdu_checksw(cmd_hex)
est_scp02_parser = argparse.ArgumentParser()
- est_scp02_parser.add_argument('--key-ver', type=auto_uint8,
required=True, help='Key Version Number (KVN)')
+ est_scp02_parser.add_argument('--key-ver', type=auto_uint8, default=0,
help='Key Version Number (KVN)')
est_scp02_parser.add_argument('--host-challenge', type=is_hexstr,
help='Hard-code the host challenge;
default: random')
est_scp02_parser.add_argument('--security-level', type=auto_uint8,
default=0x01,
@@ -900,7 +900,9 @@
class GpCardKeyset:
"""A single set of GlobalPlatform card keys and the associated KVN."""
def __init__(self, kvn: int, enc: bytes, mac: bytes, dek: bytes):
- assert 0 < kvn < 256
+ # The Key Version Number is an 8 bit integer number, where 0 refers to
the first available key,
+ # see also: GPC_SPE_034, section E.5.1.3
+ assert 0 <= kvn < 256
assert len(enc) == len(mac) == len(dek)
self.kvn = kvn
self.enc = enc
diff --git a/pySim/global_platform/scp.py b/pySim/global_platform/scp.py
index 3fe7601..72aed24 100644
--- a/pySim/global_platform/scp.py
+++ b/pySim/global_platform/scp.py
@@ -113,7 +113,39 @@
class SCP(SecureChannel, abc.ABC):
"""Abstract base class containing some common interface + functionality
for SCP protocols."""
def __init__(self, card_keys: 'GpCardKeyset', lchan_nr: int = 0):
- if hasattr(self, 'kvn_range'):
+
+ # Spec references that explain KVN ranges:
+ # TS 102 225 Annex A.1 states KVN 0x01..0x0F shall be used for SCP80
+ # GPC_GUI_003 states
+ # * For the Issuer Security Domain, this is initially Key Version
Number 'FF' which has been deliberately
+ # chosen to be outside of the allowable range ('01' to '7F') for a
Key Version Number.
+ # * It is logical that the initial keys in the Issuer Security
Domain be replaced by an initial issuer Key
+ # Version Number in the range '01' to '6F'.
+ # * Key Version Numbers '70' to '72' and '74' to '7F' are reserved
for future use.
+ # * On an implementation supporting Supplementary Security Domains,
the RSA public key with a Key Version
+ # Number '73' and a Key Identifier of '01' has the following
functionality in a Supplementary Security
+ # Domain with the DAP Verification privilege [...]
+ # GPC_GUI_010 V1.0.1 Section 6 states
+ # * Key Version number range ('20' to '2F') is reserved for SCP02
+ # * Key Version 'FF' is reserved for use by an Issuer Security
Domain supporting SCP02, and cannot be used
+ # for SCP80. This initial key set shall be replaced by a key set
with a Key Version Number in the
+ # ('20' to '2F') range.
+ # * Key Version number range ('01' to '0F') is reserved for SCP80
+ # * Key Version number '70' with Key Identifier '01' is reserved for
the Token Key, which is either a RSA
+ # public key or a DES key
+ # * Key Version number '71' with Key Identifier '01' is reserved for
the Receipt Key, which is a DES key
+ # * Key Version Number '11' is reserved for DAP as specified in ETSI
TS 102 226 [2]
+ # * Key Version Number '73' with Key Identifier '01' is reserved for
the DAP verification key as specified
+ # in sections 3.3.3 and 4 of [4], which is either an RSA public
key or DES key
+ # * Key Version Number '74' is reserved for the CASD Keys (cf.
section 9.2)
+ # * Key Version Number '75' with Key Identifier '01' is reserved for
the key used to decipher the Ciphered
+ # Load File Data Block described in section 4.8 of [5].
+
+ if card_keys.kvn == 0:
+ # Key Version Number 0x00 refers to the first available key, so we
won't carry out
+ # a range check in this case. See also: GPC_SPE_034, section
E.5.1.3
+ pass
+ elif hasattr(self, 'kvn_range'):
if not card_keys.kvn in range(self.kvn_range[0],
self.kvn_range[1]+1):
raise ValueError('%s cannot be used with KVN outside range
0x%02x..0x%02x' %
(self.__class__.__name__, self.kvn_range[0],
self.kvn_range[1]))
@@ -224,8 +256,9 @@
constr_iur = Struct('key_div_data'/Bytes(10), 'key_ver'/Int8ub,
Const(b'\x02'),
'seq_counter'/Int16ub, 'card_challenge'/Bytes(6),
'card_cryptogram'/Bytes(8))
- # The 0x70 is a non-spec special-case of sysmoISIM-SJA2/SJA5 and possibly
more sysmocom products
- kvn_ranges = [[0x20, 0x2f], [0x70, 0x70]]
+ # Key Version Number 0x70 is a non-spec special-case of
sysmoISIM-SJA2/SJA5 and possibly more sysmocom products
+ # Key Version Number 0x01 is a non-spec special-case of sysmoUSIM-SJS1
+ kvn_ranges = [[0x01, 0x01], [0x20, 0x2f], [0x70, 0x70]]
def __init__(self, *args, **kwargs):
self.overhead = 8
--
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Gerrit-MessageType: merged
Gerrit-Project: pysim
Gerrit-Branch: master
Gerrit-Change-Id: I42be2438c7f199b238f2ec7a9434cec5393210a7
Gerrit-Change-Number: 39225
Gerrit-PatchSet: 5
Gerrit-Owner: dexter <[email protected]>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria <[email protected]>
Gerrit-Reviewer: laforge <[email protected]>
