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path: root/drivers/s390/crypto/pkey_base.h
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2025-04-30s390/pkey: Provide and pass xflags within pkey and zcrypt layersHarald Freudenberger
Provide and pass the xflag parameter from pkey ioctls through the pkey handler and further down to the implementations (CCA, EP11, PCKMO and UV). So all the code is now prepared and ready to support xflags ("execution flag"). The pkey layer supports the xflag PKEY_XFLAG_NOMEMALLOC: If this flag is given in the xflags parameter, the pkey implementation is not allowed to allocate memory but instead should fall back to use preallocated memory or simple fail with -ENOMEM. This flag is for protected key derive within a cipher or similar which must not allocate memory which would cause io operations - see also the CRYPTO_ALG_ALLOCATES_MEMORY flag in crypto.h. Within the pkey handlers this flag is then to be translated to appropriate zcrypt xflags before any zcrypt related functions are called. So the PKEY_XFLAG_NOMEMALLOC translates to ZCRYPT_XFLAG_NOMEMALLOC - If this flag is set, no memory allocations which may trigger any IO operations are done. The pkey in-kernel pkey API still does not provide this xflag param. That's intended to come with a separate patch which enables this functionality. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Link: https://lore.kernel.org/r/20250424133619.16495-25-freude@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/pkey: Simplify protected key length calculation codeHarald Freudenberger
The calculation of the length of a protected key based on the protected key type is scattered over certain places within the pkey code. By introducing a new inline function pkey_keytype_to_size() this can be centralized and the calling code can be reduced and simplified. With this also comes a slight rework of the generation of protected keys. Now the pkey_pckmo module is able to generate all but ECC keys. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-05s390/pkey: Add AES xts and HMAC clear key token supportHarald Freudenberger
Add support for deriving protected keys from clear key token for AES xts and HMAC keys via PCKMO instruction. Add support for protected key generation and unwrap of protected key tokens for these key types. Furthermore 4 new sysfs attributes are introduced: - /sys/devices/virtual/misc/pkey/protkey/protkey_aes_xts_128 - /sys/devices/virtual/misc/pkey/protkey/protkey_aes_xts_256 - /sys/devices/virtual/misc/pkey/protkey/protkey_hmac_512 - /sys/devices/virtual/misc/pkey/protkey/protkey_hmac_1024 Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-08-29s390/pkey: Add function to enforce pkey handler modules loadHarald Freudenberger
There is a use case during early boot with an secure key encrypted root file system where the paes cipher may try to derive a protected key from secure key while the AP bus is still in the process of scanning the bus and building up the zcrypt device drivers. As the detection of CEX cards also triggers the modprobe of the pkey handler modules, these modules may come into existence too late. Yet another use case happening during early boot is for use of an protected key encrypted swap file(system). There is an ephemeral protected key read via sysfs to set up the swap file. But this only works when the pkey_pckmo module is already in - which may happen at a later time as the load is triggered via CPU feature. This patch introduces a new function pkey_handler_request_modules() and invokes it which unconditional tries to load in the pkey handler modules. This function is called for the in-kernel API to derive a protected key from whatever and in the sysfs API when the first attempt to simple invoke the handler function failed. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-29s390/pkey: Add slowpath function to CCA and EP11 handlerHarald Freudenberger
For some keys there exists an alternative but usually slower path to convert the key material into a protected key. This patch introduces a new handler function slowpath_key_to_protkey() which provides this alternate path for the CCA and EP11 handler code. With that even the knowledge about how and when this can be used within the pkey API code can be removed. So now the pkey API just tries the primary way and if that fails simple tries the alternative way. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-29s390/pkey: Introduce pkey base with handler registry and handler modulesHarald Freudenberger
Introduce pkey base kernel code with a simple pkey handler registry. Regroup the pkey code into these kernel modules: - pkey is the pkey api supporting the ioctls, sysfs and in-kernel api. Also the pkey base code which offers the handler registry and handler wrapping invocation functions is integrated there. This module is automatically loaded in via CPU feature if the MSA feature is available. - pkey-cca is the CCA related handler code kernel module a offering CCA specific implementation for pkey. This module is loaded in via MODULE_DEVICE_TABLE when a CEX[4-8] card becomes available. - pkey-ep11 is the EP11 related handler code kernel module offering an EP11 specific implementation for pkey. This module is loaded in via MODULE_DEVICE_TABLE when a CEX[4-8] card becomes available. - pkey-pckmo is the PCKMO related handler code kernel module. This module is loaded in via CPU feature if the MSA feature is available, but on init a check for availability of the pckmo instruction is performed. The handler modules register via a pkey_handler struct at the pkey base code and the pkey customer (that is currently the pkey api code fetches a handler via pkey handler registry functions and calls the unified handler functions via the pkey base handler functions. As a result the pkey-cca, pkey-ep11 and pkey-pckmo modules get independent from each other and it becomes possible to write new handlers which offer another kind of implementation without implicit dependencies to other handler implementations and/or kernel device drivers. For each of these 4 kernel modules there is an individual Kconfig entry: CONFIG_PKEY for the base and api, CONFIG_PKEY_CCA for the PKEY CCA support handler, CONFIG_PKEY_EP11 for the EP11 support handler and CONFIG_PKEY_PCKMO for the pckmo support. The both CEX related handler modules (PKEY CCA and PKEY EP11) have a dependency to the zcrypt api of the zcrypt device driver. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-29s390/pkey: Unify pkey cca, ep11 and pckmo functions signaturesHarald Freudenberger
As a preparation step for introducing a common function API between the pkey API module and the handlers (that is the cca, ep11 and pckmo code) this patch unifies the functions signatures exposed by the handlers and reworks all the invocation code of these functions. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-29s390/pkey: Rework and split PKEY kernel module codeHarald Freudenberger
This is a huge rework of all the pkey kernel module code. The goal is to split the code into individual parts with a dedicated calling interface: - move all the sysfs related code into pkey_sysfs.c - all the CCA related code goes to pkey_cca.c - the EP11 stuff has been moved to pkey_ep11.c - the PCKMO related code is now in pkey_pckmo.c The CCA, EP11 and PCKMO code may be seen as "handlers" with a similar calling interface. The new header file pkey_base.h declares this calling interface. The remaining code in pkey_api.c handles the ioctl, the pkey module things and the "handler" independent code on top of the calling interface invoking the handlers. This regrouping of the code will be the base for a real pkey kernel module split into a pkey base module which acts as a dispatcher and handler modules providing their service. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>