laforge has submitted this change. (
https://gerrit.osmocom.org/c/pysim/+/37947?usp=email
)
Change subject: suci-tutorial: add section about SUCI calculation by the USIM
......................................................................
suci-tutorial: add section about SUCI calculation by the USIM
The tutorial describes how SUCI calculation in the UE is configured,
let's now add a section about SUCI calculation by the USIM.
Related: OS#6531
Change-Id: I45d47f9278b30d99ebde6891de0ba8cc74b1a0a0
---
M docs/suci-tutorial.rst
1 file changed, 88 insertions(+), 14 deletions(-)
Approvals:
Jenkins Builder: Verified
laforge: Looks good to me, approved
diff --git a/docs/suci-tutorial.rst b/docs/suci-tutorial.rst
index 9227d1d..f1aef5b 100644
--- a/docs/suci-tutorial.rst
+++ b/docs/suci-tutorial.rst
@@ -1,26 +1,23 @@
Guide: Enabling 5G SUCI
-========================
+=======================
SUPI/SUCI Concealment is a feature of 5G-Standalone (SA) to encrypt the
IMSI/SUPI with a network operator public key. 3GPP Specifies two different
variants for this:
-* SUCI calculation *in the UE*, using data from the SIM
+* SUCI calculation *in the UE*, using key data from the SIM
* SUCI calculation *on the card itself*
-pySIM supports writing the 5G-specific files for *SUCI calculation in the UE* on USIM
cards, assuming that
-your cards contain the required files, and you have the privileges/credentials to write
to them. This is
-the case using sysmocom sysmoISIM-SJA2 cards (or successor products).
+pySim supports writing the 5G-specific files for *SUCI calculation in the UE* on USIM
cards, assuming
+that your cards contain the required files, and you have the privileges/credentials to
write to them.
+This is the case using sysmocom sysmoISIM-SJA2 or any flavor of sysmoISIM-SJA5.
-In short, you can enable SUCI with these steps:
+There is no 3GPP/ETSI standard method for configuring *SUCI calculation on the card*;
pySim currently
+supports the vendor-specific method for the sysmoISIM-SJA5-S17).
-* activate USIM **Service 124**
-* make sure USIM **Service 125** is disabled
-* store the public keys in **SUCI_Calc_Info**
-* set the **Routing Indicator** (required)
+This document describes both methods.
-If you want to disable the feature, you can just disable USIM Service 124 (and 125).
Technical References
~~~~~~~~~~~~~~~~~~~~
@@ -31,11 +28,29 @@
* USIM tests (incl. file content examples): `3GPP TS 31.121
<https://www.etsi.org/deliver/etsi_ts/131100_131199/131121/16.01.00_60/ts_131121v160100p.pdf>`__
* Test keys for SUCI calculation: `3GPP TS 33.501
<https://www.etsi.org/deliver/etsi_ts/133500_133599/133501/16.05.00_60/ts_133501v160500p.pdf>`__
-For specific information on sysmocom SIM cards, refer to Section 9.1 of the `sysmoUSIM
User
-Manual <https://www.sysmocom.de/manuals/sysmousim-manual.pdf>`__.
+For specific information on sysmocom SIM cards, refer to
+
+* the `symoISIM-SJA5 User Manual
<https://sysmocom.de/manuals/sysmoisim-sja5-manual.pdf>`__ for the curent
+ sysmoISIM-SJA5 product
+* the `sysmoISIM-SJA2 User Manual
<https://sysmocom.de/manuals/sysmousim-manual.pdf>`__ for the older
+ sysmoISIM-SJA2 product
--------------
+
+Enabling 5G SUCI *calculated in the UE*
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In short, you can enable *SUCI calculation in the UE* with these steps:
+
+* activate USIM **Service 124**
+* make sure USIM **Service 125** is disabled
+* store the public keys in **EF.SUCI_Calc_Info**
+* set the **Routing Indicator** (required)
+
+If you want to disable the feature, you can just disable USIM Service 124 (and 125) in
`EF.UST`.
+
+
Admin PIN
---------
@@ -185,7 +200,7 @@
USIM Error with 5G and sysmoISIM
--------------------------------
-sysmoISIMs come 5GS-enabled. By default however, the configuration stored
+sysmoISIM-SJA2 come 5GS-enabled. By default however, the configuration stored
in the card file-system is **not valid** for 5G networks: Service 124 is enabled,
but EF.SUCI_Calc_Info and EF.Routing_Indicator are empty files (hence
do not contain valid data).
@@ -194,3 +209,62 @@
whole modem shutting 5G down. If you don’t need SUCI concealment but the
smartphone refuses to connect to any 5G network, try to disable the UST
service 124.
+
+sysmoISIM-SJA5 are shipped with a more forgiving default, with valid
EF.Routing_Indicator
+contents and disabled Service 124
+
+
+SUCI calculation by the USIM
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The SUCI calculation can also be performed by the USIM application on the UICC
+directly. The UE then uses the GET IDENTITY command (see also 3GPP TS 31.102,
+section 7.5) to retrieve a SUCI value.
+
+The sysmoISIM-SJA5-S17 supports *SUCI calculation by the USIM*. The configuration
+is not much different to the above described configuration of *SUCI calculation
+in the UE*.
+
+The main difference is how the key provisioning is done. When the SUCI
+calculation is done by the USIM, then the key material is not accessed by the
+UE. The specification (see also 3GPP TS 31.102, section 7.5.1.1), also does not
+specify any file or file format to store the key material. This means the exact
+way to perform the key provisioning is an implementation detail of the USIM
+card application.
+
+In the case of sysmoISIM-SJA5-S17, the key material for *SUCI calculation by the USIM* is
stored in
+`ADF.USIM/DF.SAIP/EF.SUCI_Calc_Info` (**not** in `ADF.USIM/DF.5GS/EF.SUCI_Calc_Info`!).
+
+::
+
+ pySIM-shell (00:MF)> select MF
+ pySIM-shell (00:MF)> select ADF.USIM
+ pySIM-shell (00:MF/ADF.USIM)> select DF.SAIP
+ pySIM-shell (00:MF/ADF.USIM/DF.SAIP)> select EF.SUCI_Calc_Info
+
+The file format is exactly the same as specified in 3GPP TS 31.102, section
+4.4.11.8. This means the above described key provisioning procedure can be
+applied without any changes, except that the file location is different.
+
+To signal to the UE that the USIM is setup up for SUCI calculation, service
+125 must be enabled in addition to service 124 (see also 3GPP TS 31.102,
+section 5.3.48)
+
+::
+
+ pySIM-shell (00:MF/ADF.USIM/EF.UST)> ust_service_activate 124
+ pySIM-shell (00:MF/ADF.USIM/EF.UST)> ust_service_activate 125
+
+To verify that the SUCI calculation works as expected, it is possible to issue
+a GET IDENTITY command using pySim-shell:
+
+::
+
+ select ADF.USIM
+ get_identity
+
+The USIM should then return a SUCI TLV Data object that looks like this:
+
+::
+
+ SUCI TLV Data Object:
0199f90717ff021b027a2c58ce1c6b89df088a9eb4d242596dd75746bb5f3503d2cf58a7461e4fd106e205c86f76544e9d732226a4e1
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Gerrit-MessageType: merged
Gerrit-Project: pysim
Gerrit-Branch: master
Gerrit-Change-Id: I45d47f9278b30d99ebde6891de0ba8cc74b1a0a0
Gerrit-Change-Number: 37947
Gerrit-PatchSet: 4
Gerrit-Owner: dexter <pmaier(a)sysmocom.de>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria <vyanitskiy(a)sysmocom.de>
Gerrit-Reviewer: laforge <laforge(a)osmocom.org>