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