This patch introduces a new in-kernel-crypto blockcipher
called 'paes' which implements AES with protected keys.
The paes blockcipher can be used similar to the aes
blockcipher but uses secure key material to derive the
working protected key and so offers an encryption
implementation where never a clear key value is exposed
in memory.
The paes module is only available for the s390 platform
providing a minimal hardware support of CPACF enabled
with at least MSA level 3. Upon module initialization
these requirements are checked.
Includes additional contribution from Harald Freudenberger.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Adding the PCKMO inline function and the function code definitions
for using the pckmo function to the cpacf header file.
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The CPACF code makes some assumptions about the availablity of hardware
support. E.g. if the machine supports KM(AES-256) without chaining it is
assumed that KMC(AES-256) with chaining is available as well. For the
existing CPUs this is true but the architecturally correct way is to
check each CPACF functions on its own. This is what the query function
of each instructions is all about.
Reviewed-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The CPACF instructions can complete with three different condition codes:
CC=0 for successful completion, CC=1 if the protected key verification
failed, and CC=3 for partial completion.
The inline functions will restart the CPACF instruction for partial
completion, this removes the CC=3 case. The CC=1 case is only relevant
for the protected key functions of the KM, KMC, KMAC and KMCTR
instructions. As the protected key functions are not used by the
current code, there is no need for any kind of return code handling.
Reviewed-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use a separate define for the decryption modifier bit instead of
duplicating the function codes for encryption / decrypton.
In addition use an unsigned type for the function code.
Reviewed-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
KVM will have to query these functions, let's add at least the query
capabilities.
PCKMO has RRE format, as bit 16-31 are ignored, we can still use the
existing function. As PCKMO won't touch the cc, let's force it to 0
upfront.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The CPACF instructions are going be used in KVM as well, move the
defines and the inline functions from arch/s390/crypt/crypt_s390.h
to arch/s390/include/asm. Rename the header to cpacf.h and replace
the crypt_s390_xxx names with cpacf_xxx.
While we are at it, cleanup the header as well. The encoding for
the CPACF operations is odd, there is an enum for each of the CPACF
instructions with the hardware function code in the lower 8 bits of
each entry and a software defined number for the CPACF instruction
in the upper 8 bits. Remove the superfluous software number and
replace the enums with simple defines.
The crypt_s390_func_available() function tests for the presence
of a specific CPACF operations. The new name of the function is
cpacf_query and it works slightly different than before. It gets
passed an opcode of an CPACF instruction and a function code for
this instruction. The facility_mask parameter is gone, the opcode
is used to find the correct MSA facility bit to check if the CPACF
instruction itself is available. If it is the query function of the
given instruction is used to test if the requested CPACF operation
is present.
Acked-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Martin Schwidefsky