Commit Graph

9 Commits

Author SHA1 Message Date
Harald Freudenberger
fa6999e326 s390/pkey: support CCA and EP11 secure ECC private keys
This patch extends the pkey kernel module to support CCA
and EP11 secure ECC (private) keys as source for deriving
ECC protected (private) keys.

There is yet another new ioctl to support this: PKEY_KBLOB2PROTK3
can handle all the old keys plus CCA and EP11 secure ECC keys.
For details see ioctl description in pkey.h.

The CPACF unit currently only supports a subset of 5
different ECC curves (P-256, P-384, P-521, ED25519, ED448) and
so only keys of this curve type can be transformed into
protected keys. However, the pkey and the cca/ep11 low level
functions do not check this but simple pass-through the key
blob to the firmware onto the crypto cards. So most likely
the failure will be a response carrying an error code
resulting in user space errno value EIO instead of EINVAL.

Deriving a protected key from an EP11 ECC secure key
requires a CEX7 in EP11 mode. Deriving a protected key from
an CCA ECC secure key requires a CEX7 in CCA mode.

Together with this new ioctl the ioctls for querying lists
of apqns (PKEY_APQNS4K and PKEY_APQNS4KT) have been extended
to support EP11 and CCA ECC secure key type and key blobs.

Together with this ioctl there comes a new struct ep11kblob_header
which is to be prepended onto the EP11 key blob. See details
in pkey.h for the fields in there. The older EP11 AES key blob
with some info stored in the (unused) session field is also
supported with this new ioctl.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-24 10:03:28 +02:00
Harald Freudenberger
32ca04bba6 s390/zcrypt: Support for CCA APKA master keys
Support for CCA APKA (used for CCA ECC keys) master keys.
The existing mkvps sysfs attribute for each queue for cards
in CCA mode is extended to show the APKA master key register
states and verification pattern:

Improve the mkvps sysfs attribute to display the APKA
master key verification patterns for old, current and new
master key registers. The APKA master key is used to
encrypt CCA ECC secure keys. The syntax is analog to the
existing AES mk verification patterns:

    APKA NEW: <new_apka_mk_state> <new_apka_mk_mkvp>
    APKA CUR: <cur_apka_mk_state> <cur_apka_mk_mkvp>
    APKA OLD: <old_apka_mk_state> <old_apka_mk_mkvp>
  with
    <new_apka_mk_state>: 'empty' or 'partial' or 'full'
    <cur_apka_mk_state>: 'valid' or 'invalid'
    <old_apka_mk_state>: 'valid' or 'invalid'
    <new_apka_mk_mkvp>, <cur_apka_mk_mkvp>, <old_apka_mk_mkvp>
      8 byte hex string with leading 0x

MKVP means Master Key Verification Pattern and is a folded hash over
the key value. Only the states 'full' and 'valid' result in displaying
a useful mkvp, otherwise a mkvp of all bytes zero is shown. If for any
reason the FQ fails and the (cached) information is not available, the
state '-' will be shown with the mkvp value also '-'. The values shown
here are the very same as the cca panel tools displays.

The internal function cca_findcard2() also supports to match
against the APKA master key verification patterns and the pkey
kernel module which uses this function needed compatible rewrite
of these invocations.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-24 10:03:28 +02:00
Gustavo A. R. Silva
fa226f1d81 s390: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Link: https://lkml.kernel.org/r/20200221150612.GA9717@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-02-27 16:02:21 +01:00
Harald Freudenberger
888edbc488 s390/pkey: Add support for key blob with clear key value
This patch adds support for a new key blob format to the
pkey kernel module. The new key blob comprises a clear
key value together with key type information.

The implementation tries to derive an protected key
from the blob with the clear key value inside with
1) the PCKMO instruction. This may fail as the LPAR
   profile may disable this way.
2) Generate an CCA AES secure data key with exact the
   clear key value. This requires to have a working
   crypto card in CCA Coprocessor mode. Then derive
   an protected key from the CCA AES secure key again
   with the help of a working crypto card in CCA mode.
If both way fail, the transformation of the clear key
blob into a protected key will fail. For the PAES cipher
this would result in a failure at setkey() invocation.

A clear key value exposed in main memory is a security
risk. The intention of this new 'clear key blob' support
for pkey is to provide self-tests for the PAES cipher key
implementation. These known answer tests obviously need
to be run with well known key values. So with the clear
key blob format there is a way to provide knwon answer
tests together with an pkey clear key blob for the
in-kernel self tests done at cipher registration.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-01-30 13:07:55 +01:00
Harald Freudenberger
f2bbc96e7c s390/pkey: add CCA AES cipher key support
Introduce new ioctls and structs to be used with these new ioctls
which are able to handle CCA AES secure keys and CCA AES cipher keys:

PKEY_GENSECK2: Generate secure key, version 2.
  Generate either a CCA AES secure key or a CCA AES cipher key.

PKEY_CLR2SECK2: Generate secure key from clear key value, version 2.
  Construct a CCA AES secure key or CCA AES cipher key from a given
  clear key value.

PKEY_VERIFYKEY2: Verify the given secure key, version 2.
  Check for correct key type. If cardnr and domain are given, also
  check if this apqn is able to handle this type of key. If cardnr and
  domain are 0xFFFF, on return these values are filled with an apqn
  able to handle this key. The function also checks for the master key
  verification patterns of the key matching to the current or
  alternate mkvp of the apqn. CCA AES cipher keys are also checked
  for CPACF export allowed (CPRTCPAC flag). Currently CCA AES secure
  keys and CCA AES cipher keys are supported (may get extended in the
  future).

PKEY_KBLOB2PROTK2: Transform a key blob (of any type) into
  a protected key, version 2. Difference to version 1 is only that
  this new ioctl has additional parameters to provide a list of
  apqns to be used for the transformation.

PKEY_APQNS4K: Generate a list of APQNs based on the key blob given.
  Is able to find out which type of secure key is given (CCA AES
  secure key or CCA AES cipher key) and tries to find all matching
  crypto cards based on the MKVP and maybe other criterias (like CCA
  AES cipher keys need a CEX6C or higher). The list of APQNs is
  further filtered by the key's mkvp which needs to match to either
  the current mkvp or the alternate mkvp (which is the old mkvp on CCA
  adapters) of the apqns. The flags argument may be used to limit the
  matching apqns. If the PKEY_FLAGS_MATCH_CUR_MKVP is given, only the
  current mkvp of each apqn is compared. Likewise with the
  PKEY_FLAGS_MATCH_ALT_MKVP. If both are given it is assumed to return
  apqns where either the current or the alternate mkvp matches. If no
  matching APQN is found, the ioctl returns with 0 but the
  apqn_entries value is 0.

PKEY_APQNS4KT: Generate a list of APQNs based on the key type given.
  Build a list of APQNs based on the given key type and maybe further
  restrict the list by given master key verification patterns.
  For different key types there may be different ways to match the
  master key verification patterns. For CCA keys (CCA data key and CCA
  cipher key) the first 8 bytes of cur_mkvp refer to the current mkvp
  value of the apqn and the first 8 bytes of the alt_mkvp refer to the
  old mkvp. The flags argument controls if the apqns current and/or
  alternate mkvp should match. If the PKEY_FLAGS_MATCH_CUR_MKVP is
  given, only the current mkvp of each apqn is compared. Likewise with
  the PKEY_FLAGS_MATCH_ALT_MKVP. If both are given, it is assumed to
  return apqns where either the current or the alternate mkvp
  matches. If no matching APQN is found, the ioctl returns with 0 but
  the apqn_entries value is 0.

These new ioctls are now prepared for another new type of secure key
blob which may come in the future. They all use a pointer to the key
blob and a key blob length information instead of some hardcoded byte
array. They all use the new enums pkey_key_type, pkey_key_size and
pkey_key_info for getting/setting key type, key size and additional
info about the key. All but the PKEY_VERIFY2 ioctl now work based on a
list of apqns. This list is walked through trying to perform the
operation on exactly this apqn without any further checking (like card
type or online state). If the apqn fails, simple the next one in the
list is tried until success (return 0) or the end of the list is
reached (return -1 with errno ENODEV). All apqns in the list need to
be exact apqns (0xFFFF as any card or domain is not allowed). There
are two new ioctls which can be used to build a list of apqns based on
a key or key type and maybe restricted by match to a current or
alternate master key verifcation pattern.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-21 12:58:54 +02:00
Harald Freudenberger
4bc123b18c s390/zcrypt: Add low level functions for CCA AES cipher keys
This patch adds low level functions, structs and defines to support
CCA AES cipher keys:
- struct cipherkeytoken can be used for an inside view of the CCA AES
  cipher key token blob.
- function cca_cipher2protkey() derives an CPACF protected key from an
  CCA AES cipher key.
- function cca_gencipherkey() generates an CCA AES cipher key with
  random value.
- function cca_findcard2() constructs a list of apqns based on input
  constrains like min hardware type, mkvp values.
- cca_check_secaescipherkey() does a check on the given CCA AES cipher
  key blob.
- cca_clr2cipherkey() generates an CCA AES cipher key from a given
  clear key value.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-21 12:58:54 +02:00
Harald Freudenberger
4da57a2fea s390/zcrypt: extend cca_findcard function and helper
Rework and extension of the cca_findcard function to be prepared for
other types of secure key blobs. Split the function and extract an
internal function which has no awareness of key blobs any
more. Improve this function and the helper code around to be able to
check for a minimal crypto card hardware level (Background: the newer
AES cipher keys need to match to the master key verification pattern
and need to have a crypto card CEX6 or higher).

No API change, neither for the in-kernel API nor the ioctl interface.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-21 12:58:54 +02:00
Harald Freudenberger
7c4e91c095 s390/zcrypt: new sysfs attributes serialnr and mkvps
This patch extends the sysfs interface with two new attributes for the
CEX4, CEX5 and CEX6 crypto cards/queues in coprocessor ('CCA') mode:
  /sys/devices/ap/cardxx/serialnr
  /sys/devices/ap/cardxx/xx.yyyy/mkvps

The serialnr attribute is card based and shows the 8 character ASCII
serial number string which should unique identify the card.

The mkvps is queue based and displays 3 lines of information about the
new, current and old master key register:
  AES NEW: <new_aes_mk_state> <new_aes_mk_mkvp>
  AES CUR: <cur_aes_mk_state> <cur_aes_mk_mkvp>
  AES OLD: <old_aes_mk_state> <old_aes_mk_mkvp>
with
  <new_aes_mk_state>: 'empty' or 'partial' or 'full'
  <cur_aes_mk_state>: 'valid' or 'invalid'
  <old_aes_mk_state>: 'valid' or 'invalid'
  <new_aes_mk_mkvp>, <cur_aes_mk_mkvp>, <old_aes_mk_mkvp>
    8 byte hex string with leading 0x
MKVP means Master Key Verification Pattern and is a folded hash over
the key value. Only the states 'full' and 'valid' result in displaying
a useful mkvp, otherwise a mkvp of all bytes zero is shown. If for any
reason the FQ fails and the (cached) information is not available, the
state '-' will be shown with the mkvp value also '-'. The values shown
here are the very same as the cca panel tools displays. As of now only
the AES master keys states and verification patterns are shown. A CCA
APQN also has similar master key registers for DES, RSA and ECC. So
the content of this attribute may get extended.

Reading the sysfs attribute automatically triggers an FQ CPRB to be
sent to the queue as long as the queue is (soft-) online. For the
serialnr attribute the queue with the default domain id is addressed
(if available and valid). This is reasonable as it is assumed that
this sysfs interface is not performance critical and on the other side
a master key change should be visiable as soon as possible. When a
queue is (soft-) offline however, the cached values are displayed. If
no cached values are available, the serial number string will be empty
and the mkvp lines will show state '-' and mkvp value '-'.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-07-29 18:14:17 +02:00
Harald Freudenberger
efc598e6c8 s390/zcrypt: move cca misc functions to new code file
Rework of the pkey code. Moved all the cca generic code
away from pkey_api.c into a new file zcrypt_ccamisc.c.
This new file is now part of the zcrypt device driver
and exports a bunch of cca functions to pkey and may
be called from other kernel modules as well.

The pkey ioctl API is unchanged.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-07-29 18:14:17 +02:00