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linux/drivers/s390/crypto/pkey_cca.c
Harald Freudenberger e5a7f7e0c6 s390/pkey: Provide and pass xflags within pkey and zcrypt layers 
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>
2025-04-30 11:34:03 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* pkey cca specific code
*
* Copyright IBM Corp. 2024
*/
#define KMSG_COMPONENT "pkey"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/init.h>
#include <linux/module.h>
#include <linux/cpufeature.h>
#include "zcrypt_ccamisc.h"
#include "pkey_base.h"
MODULE_LICENSE("GPL");
MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("s390 protected key CCA handler");
#if IS_MODULE(CONFIG_PKEY_CCA)
static struct ap_device_id pkey_cca_card_ids[] = {
{ .dev_type = AP_DEVICE_TYPE_CEX4 },
{ .dev_type = AP_DEVICE_TYPE_CEX5 },
{ .dev_type = AP_DEVICE_TYPE_CEX6 },
{ .dev_type = AP_DEVICE_TYPE_CEX7 },
{ .dev_type = AP_DEVICE_TYPE_CEX8 },
{ /* end of list */ },
};
MODULE_DEVICE_TABLE(ap, pkey_cca_card_ids);
#endif
/*
* Check key blob for known and supported CCA key.
*/
static bool is_cca_key(const u8 *key, u32 keylen)
{
struct keytoken_header *hdr = (struct keytoken_header *)key;
if (keylen < sizeof(*hdr))
return false;
switch (hdr->type) {
case TOKTYPE_CCA_INTERNAL:
switch (hdr->version) {
case TOKVER_CCA_AES:
case TOKVER_CCA_VLSC:
return true;
default:
return false;
}
case TOKTYPE_CCA_INTERNAL_PKA:
return true;
default:
return false;
}
}
static bool is_cca_keytype(enum pkey_key_type key_type)
{
switch (key_type) {
case PKEY_TYPE_CCA_DATA:
case PKEY_TYPE_CCA_CIPHER:
case PKEY_TYPE_CCA_ECC:
return true;
default:
return false;
}
}
static int cca_apqns4key(const u8 *key, u32 keylen, u32 flags,
struct pkey_apqn *apqns, size_t *nr_apqns, u32 pflags)
{
struct keytoken_header *hdr = (struct keytoken_header *)key;
u32 _apqns[MAXAPQNSINLIST], _nr_apqns = ARRAY_SIZE(_apqns);
u32 xflags;
int rc;
xflags = pflags & PKEY_XFLAG_NOMEMALLOC ? ZCRYPT_XFLAG_NOMEMALLOC : 0;
if (!flags)
flags = PKEY_FLAGS_MATCH_CUR_MKVP | PKEY_FLAGS_MATCH_ALT_MKVP;
if (keylen < sizeof(struct keytoken_header))
return -EINVAL;
zcrypt_wait_api_operational();
if (hdr->type == TOKTYPE_CCA_INTERNAL) {
u64 cur_mkvp = 0, old_mkvp = 0;
int minhwtype = ZCRYPT_CEX3C;
if (hdr->version == TOKVER_CCA_AES) {
struct secaeskeytoken *t = (struct secaeskeytoken *)key;
if (flags & PKEY_FLAGS_MATCH_CUR_MKVP)
cur_mkvp = t->mkvp;
if (flags & PKEY_FLAGS_MATCH_ALT_MKVP)
old_mkvp = t->mkvp;
} else if (hdr->version == TOKVER_CCA_VLSC) {
struct cipherkeytoken *t = (struct cipherkeytoken *)key;
minhwtype = ZCRYPT_CEX6;
if (flags & PKEY_FLAGS_MATCH_CUR_MKVP)
cur_mkvp = t->mkvp0;
if (flags & PKEY_FLAGS_MATCH_ALT_MKVP)
old_mkvp = t->mkvp0;
} else {
/* unknown CCA internal token type */
return -EINVAL;
}
rc = cca_findcard2(_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
minhwtype, AES_MK_SET,
cur_mkvp, old_mkvp, xflags);
if (rc)
goto out;
} else if (hdr->type == TOKTYPE_CCA_INTERNAL_PKA) {
struct eccprivkeytoken *t = (struct eccprivkeytoken *)key;
u64 cur_mkvp = 0, old_mkvp = 0;
if (t->secid == 0x20) {
if (flags & PKEY_FLAGS_MATCH_CUR_MKVP)
cur_mkvp = t->mkvp;
if (flags & PKEY_FLAGS_MATCH_ALT_MKVP)
old_mkvp = t->mkvp;
} else {
/* unknown CCA internal 2 token type */
return -EINVAL;
}
rc = cca_findcard2(_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
ZCRYPT_CEX7, APKA_MK_SET,
cur_mkvp, old_mkvp, xflags);
if (rc)
goto out;
} else {
PKEY_DBF_ERR("%s unknown/unsupported blob type %d version %d\n",
__func__, hdr->type, hdr->version);
return -EINVAL;
}
if (apqns) {
if (*nr_apqns < _nr_apqns)
rc = -ENOSPC;
else
memcpy(apqns, _apqns, _nr_apqns * sizeof(u32));
}
*nr_apqns = _nr_apqns;
out:
pr_debug("rc=%d\n", rc);
return rc;
}
static int cca_apqns4type(enum pkey_key_type ktype,
u8 cur_mkvp[32], u8 alt_mkvp[32], u32 flags,
struct pkey_apqn *apqns, size_t *nr_apqns,
u32 pflags)
{
u32 _apqns[MAXAPQNSINLIST], _nr_apqns = ARRAY_SIZE(_apqns);
u32 xflags;
int rc;
xflags = pflags & PKEY_XFLAG_NOMEMALLOC ? ZCRYPT_XFLAG_NOMEMALLOC : 0;
zcrypt_wait_api_operational();
if (ktype == PKEY_TYPE_CCA_DATA || ktype == PKEY_TYPE_CCA_CIPHER) {
u64 cur_mkvp = 0, old_mkvp = 0;
int minhwtype = ZCRYPT_CEX3C;
if (flags & PKEY_FLAGS_MATCH_CUR_MKVP)
cur_mkvp = *((u64 *)cur_mkvp);
if (flags & PKEY_FLAGS_MATCH_ALT_MKVP)
old_mkvp = *((u64 *)alt_mkvp);
if (ktype == PKEY_TYPE_CCA_CIPHER)
minhwtype = ZCRYPT_CEX6;
rc = cca_findcard2(_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
minhwtype, AES_MK_SET,
cur_mkvp, old_mkvp, xflags);
if (rc)
goto out;
} else if (ktype == PKEY_TYPE_CCA_ECC) {
u64 cur_mkvp = 0, old_mkvp = 0;
if (flags & PKEY_FLAGS_MATCH_CUR_MKVP)
cur_mkvp = *((u64 *)cur_mkvp);
if (flags & PKEY_FLAGS_MATCH_ALT_MKVP)
old_mkvp = *((u64 *)alt_mkvp);
rc = cca_findcard2(_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
ZCRYPT_CEX7, APKA_MK_SET,
cur_mkvp, old_mkvp, xflags);
if (rc)
goto out;
} else {
PKEY_DBF_ERR("%s unknown/unsupported key type %d",
__func__, (int)ktype);
return -EINVAL;
}
if (apqns) {
if (*nr_apqns < _nr_apqns)
rc = -ENOSPC;
else
memcpy(apqns, _apqns, _nr_apqns * sizeof(u32));
}
*nr_apqns = _nr_apqns;
out:
pr_debug("rc=%d\n", rc);
return rc;
}
static int cca_key2protkey(const struct pkey_apqn *apqns, size_t nr_apqns,
const u8 *key, u32 keylen,
u8 *protkey, u32 *protkeylen, u32 *protkeytype,
u32 pflags)
{
struct keytoken_header *hdr = (struct keytoken_header *)key;
struct pkey_apqn _apqns[MAXAPQNSINLIST];
u32 xflags;
int i, rc;
xflags = pflags & PKEY_XFLAG_NOMEMALLOC ? ZCRYPT_XFLAG_NOMEMALLOC : 0;
if (keylen < sizeof(*hdr))
return -EINVAL;
if (hdr->type == TOKTYPE_CCA_INTERNAL &&
hdr->version == TOKVER_CCA_AES) {
/* CCA AES data key */
if (keylen < sizeof(struct secaeskeytoken))
return -EINVAL;
if (cca_check_secaeskeytoken(pkey_dbf_info, 3, key, 0))
return -EINVAL;
} else if (hdr->type == TOKTYPE_CCA_INTERNAL &&
hdr->version == TOKVER_CCA_VLSC) {
/* CCA AES cipher key */
if (keylen < hdr->len)
return -EINVAL;
if (cca_check_secaescipherkey(pkey_dbf_info,
3, key, 0, 1))
return -EINVAL;
} else if (hdr->type == TOKTYPE_CCA_INTERNAL_PKA) {
/* CCA ECC (private) key */
if (keylen < sizeof(struct eccprivkeytoken))
return -EINVAL;
if (cca_check_sececckeytoken(pkey_dbf_info, 3, key, keylen, 1))
return -EINVAL;
} else {
PKEY_DBF_ERR("%s unknown/unsupported blob type %d version %d\n",
__func__, hdr->type, hdr->version);
return -EINVAL;
}
zcrypt_wait_api_operational();
if (!apqns || (nr_apqns == 1 &&
apqns[0].card == 0xFFFF && apqns[0].domain == 0xFFFF)) {
nr_apqns = MAXAPQNSINLIST;
rc = cca_apqns4key(key, keylen, 0, _apqns, &nr_apqns, pflags);
if (rc)
goto out;
apqns = _apqns;
}
for (rc = -ENODEV, i = 0; rc && i < nr_apqns; i++) {
if (hdr->type == TOKTYPE_CCA_INTERNAL &&
hdr->version == TOKVER_CCA_AES) {
rc = cca_sec2protkey(apqns[i].card, apqns[i].domain,
key, protkey,
protkeylen, protkeytype, xflags);
} else if (hdr->type == TOKTYPE_CCA_INTERNAL &&
hdr->version == TOKVER_CCA_VLSC) {
rc = cca_cipher2protkey(apqns[i].card, apqns[i].domain,
key, protkey,
protkeylen, protkeytype, xflags);
} else if (hdr->type == TOKTYPE_CCA_INTERNAL_PKA) {
rc = cca_ecc2protkey(apqns[i].card, apqns[i].domain,
key, protkey,
protkeylen, protkeytype, xflags);
} else {
rc = -EINVAL;
break;
}
}
out:
pr_debug("rc=%d\n", rc);
return rc;
}
/*
* Generate CCA secure key.
* As of now only CCA AES Data or Cipher secure keys are
* supported.
* keytype is one of the PKEY_KEYTYPE_* constants,
* subtype may be 0 or PKEY_TYPE_CCA_DATA or PKEY_TYPE_CCA_CIPHER,
* keybitsize is the bit size of the key (may be 0 for
* keytype PKEY_KEYTYPE_AES_*).
*/
static int cca_gen_key(const struct pkey_apqn *apqns, size_t nr_apqns,
u32 keytype, u32 subtype,
u32 keybitsize, u32 flags,
u8 *keybuf, u32 *keybuflen, u32 *_keyinfo, u32 pflags)
{
struct pkey_apqn _apqns[MAXAPQNSINLIST];
int i, len, rc;
u32 xflags;
xflags = pflags & PKEY_XFLAG_NOMEMALLOC ? ZCRYPT_XFLAG_NOMEMALLOC : 0;
/* check keytype, subtype, keybitsize */
switch (keytype) {
case PKEY_KEYTYPE_AES_128:
case PKEY_KEYTYPE_AES_192:
case PKEY_KEYTYPE_AES_256:
len = pkey_keytype_aes_to_size(keytype);
if (keybitsize && keybitsize != 8 * len) {
PKEY_DBF_ERR("%s unknown/unsupported keybitsize %d\n",
__func__, keybitsize);
return -EINVAL;
}
keybitsize = 8 * len;
switch (subtype) {
case PKEY_TYPE_CCA_DATA:
case PKEY_TYPE_CCA_CIPHER:
break;
default:
PKEY_DBF_ERR("%s unknown/unsupported subtype %d\n",
__func__, subtype);
return -EINVAL;
}
break;
default:
PKEY_DBF_ERR("%s unknown/unsupported keytype %d\n",
__func__, keytype);
return -EINVAL;
}
zcrypt_wait_api_operational();
if (!apqns || (nr_apqns == 1 &&
apqns[0].card == 0xFFFF && apqns[0].domain == 0xFFFF)) {
nr_apqns = MAXAPQNSINLIST;
rc = cca_apqns4type(subtype, NULL, NULL, 0,
_apqns, &nr_apqns, pflags);
if (rc)
goto out;
apqns = _apqns;
}
for (rc = -ENODEV, i = 0; rc && i < nr_apqns; i++) {
if (subtype == PKEY_TYPE_CCA_CIPHER) {
rc = cca_gencipherkey(apqns[i].card, apqns[i].domain,
keybitsize, flags,
keybuf, keybuflen, xflags);
} else {
/* PKEY_TYPE_CCA_DATA */
rc = cca_genseckey(apqns[i].card, apqns[i].domain,
keybitsize, keybuf, xflags);
*keybuflen = (rc ? 0 : SECKEYBLOBSIZE);
}
}
out:
pr_debug("rc=%d\n", rc);
return rc;
}
/*
* Generate CCA secure key with given clear key value.
* As of now only CCA AES Data or Cipher secure keys are
* supported.
* keytype is one of the PKEY_KEYTYPE_* constants,
* subtype may be 0 or PKEY_TYPE_CCA_DATA or PKEY_TYPE_CCA_CIPHER,
* keybitsize is the bit size of the key (may be 0 for
* keytype PKEY_KEYTYPE_AES_*).
*/
static int cca_clr2key(const struct pkey_apqn *apqns, size_t nr_apqns,
u32 keytype, u32 subtype,
u32 keybitsize, u32 flags,
const u8 *clrkey, u32 clrkeylen,
u8 *keybuf, u32 *keybuflen, u32 *_keyinfo, u32 pflags)
{
struct pkey_apqn _apqns[MAXAPQNSINLIST];
int i, len, rc;
u32 xflags;
xflags = pflags & PKEY_XFLAG_NOMEMALLOC ? ZCRYPT_XFLAG_NOMEMALLOC : 0;
/* check keytype, subtype, clrkeylen, keybitsize */
switch (keytype) {
case PKEY_KEYTYPE_AES_128:
case PKEY_KEYTYPE_AES_192:
case PKEY_KEYTYPE_AES_256:
len = pkey_keytype_aes_to_size(keytype);
if (keybitsize && keybitsize != 8 * len) {
PKEY_DBF_ERR("%s unknown/unsupported keybitsize %d\n",
__func__, keybitsize);
return -EINVAL;
}
keybitsize = 8 * len;
if (clrkeylen != len) {
PKEY_DBF_ERR("%s invalid clear key len %d != %d\n",
__func__, clrkeylen, len);
return -EINVAL;
}
switch (subtype) {
case PKEY_TYPE_CCA_DATA:
case PKEY_TYPE_CCA_CIPHER:
break;
default:
PKEY_DBF_ERR("%s unknown/unsupported subtype %d\n",
__func__, subtype);
return -EINVAL;
}
break;
default:
PKEY_DBF_ERR("%s unknown/unsupported keytype %d\n",
__func__, keytype);
return -EINVAL;
}
zcrypt_wait_api_operational();
if (!apqns || (nr_apqns == 1 &&
apqns[0].card == 0xFFFF && apqns[0].domain == 0xFFFF)) {
nr_apqns = MAXAPQNSINLIST;
rc = cca_apqns4type(subtype, NULL, NULL, 0,
_apqns, &nr_apqns, pflags);
if (rc)
goto out;
apqns = _apqns;
}
for (rc = -ENODEV, i = 0; rc && i < nr_apqns; i++) {
if (subtype == PKEY_TYPE_CCA_CIPHER) {
rc = cca_clr2cipherkey(apqns[i].card, apqns[i].domain,
keybitsize, flags, clrkey,
keybuf, keybuflen, xflags);
} else {
/* PKEY_TYPE_CCA_DATA */
rc = cca_clr2seckey(apqns[i].card, apqns[i].domain,
keybitsize, clrkey, keybuf, xflags);
*keybuflen = (rc ? 0 : SECKEYBLOBSIZE);
}
}
out:
pr_debug("rc=%d\n", rc);
return rc;
}
static int cca_verifykey(const u8 *key, u32 keylen,
u16 *card, u16 *dom,
u32 *keytype, u32 *keybitsize, u32 *flags, u32 pflags)
{
struct keytoken_header *hdr = (struct keytoken_header *)key;
u32 apqns[MAXAPQNSINLIST], nr_apqns = ARRAY_SIZE(apqns);
u32 xflags;
int rc;
xflags = pflags & PKEY_XFLAG_NOMEMALLOC ? ZCRYPT_XFLAG_NOMEMALLOC : 0;
if (keylen < sizeof(*hdr))
return -EINVAL;
zcrypt_wait_api_operational();
if (hdr->type == TOKTYPE_CCA_INTERNAL &&
hdr->version == TOKVER_CCA_AES) {
struct secaeskeytoken *t = (struct secaeskeytoken *)key;
rc = cca_check_secaeskeytoken(pkey_dbf_info, 3, key, 0);
if (rc)
goto out;
*keytype = PKEY_TYPE_CCA_DATA;
*keybitsize = t->bitsize;
rc = cca_findcard2(apqns, &nr_apqns, *card, *dom,
ZCRYPT_CEX3C, AES_MK_SET,
t->mkvp, 0, xflags);
if (!rc)
*flags = PKEY_FLAGS_MATCH_CUR_MKVP;
if (rc == -ENODEV) {
nr_apqns = ARRAY_SIZE(apqns);
rc = cca_findcard2(apqns, &nr_apqns, *card, *dom,
ZCRYPT_CEX3C, AES_MK_SET,
0, t->mkvp, xflags);
if (!rc)
*flags = PKEY_FLAGS_MATCH_ALT_MKVP;
}
if (rc)
goto out;
*card = ((struct pkey_apqn *)apqns)->card;
*dom = ((struct pkey_apqn *)apqns)->domain;
} else if (hdr->type == TOKTYPE_CCA_INTERNAL &&
hdr->version == TOKVER_CCA_VLSC) {
struct cipherkeytoken *t = (struct cipherkeytoken *)key;
rc = cca_check_secaescipherkey(pkey_dbf_info, 3, key, 0, 1);
if (rc)
goto out;
*keytype = PKEY_TYPE_CCA_CIPHER;
*keybitsize = PKEY_SIZE_UNKNOWN;
if (!t->plfver && t->wpllen == 512)
*keybitsize = PKEY_SIZE_AES_128;
else if (!t->plfver && t->wpllen == 576)
*keybitsize = PKEY_SIZE_AES_192;
else if (!t->plfver && t->wpllen == 640)
*keybitsize = PKEY_SIZE_AES_256;
rc = cca_findcard2(apqns, &nr_apqns, *card, *dom,
ZCRYPT_CEX6, AES_MK_SET,
t->mkvp0, 0, xflags);
if (!rc)
*flags = PKEY_FLAGS_MATCH_CUR_MKVP;
if (rc == -ENODEV) {
nr_apqns = ARRAY_SIZE(apqns);
rc = cca_findcard2(apqns, &nr_apqns, *card, *dom,
ZCRYPT_CEX6, AES_MK_SET,
0, t->mkvp0, xflags);
if (!rc)
*flags = PKEY_FLAGS_MATCH_ALT_MKVP;
}
if (rc)
goto out;
*card = ((struct pkey_apqn *)apqns)->card;
*dom = ((struct pkey_apqn *)apqns)->domain;
} else {
/* unknown/unsupported key blob */
rc = -EINVAL;
}
out:
pr_debug("rc=%d\n", rc);
return rc;
}
/*
* This function provides an alternate but usually slow way
* to convert a 'clear key token' with AES key material into
* a protected key. This is done via an intermediate step
* which creates a CCA AES DATA secure key first and then
* derives the protected key from this secure key.
*/
static int cca_slowpath_key2protkey(const struct pkey_apqn *apqns,
size_t nr_apqns,
const u8 *key, u32 keylen,
u8 *protkey, u32 *protkeylen,
u32 *protkeytype, u32 pflags)
{
const struct keytoken_header *hdr = (const struct keytoken_header *)key;
const struct clearkeytoken *t = (const struct clearkeytoken *)key;
u8 tmpbuf[SECKEYBLOBSIZE]; /* 64 bytes */
u32 tmplen, keysize = 0;
int i, rc;
if (keylen < sizeof(*hdr))
return -EINVAL;
if (hdr->type == TOKTYPE_NON_CCA &&
hdr->version == TOKVER_CLEAR_KEY)
keysize = pkey_keytype_aes_to_size(t->keytype);
if (!keysize || t->len != keysize)
return -EINVAL;
/* try two times in case of failure */
for (i = 0, rc = -ENODEV; i < 2 && rc; i++) {
tmplen = SECKEYBLOBSIZE;
rc = cca_clr2key(NULL, 0, t->keytype, PKEY_TYPE_CCA_DATA,
8 * keysize, 0, t->clearkey, t->len,
tmpbuf, &tmplen, NULL, pflags);
pr_debug("cca_clr2key()=%d\n", rc);
if (rc)
continue;
rc = cca_key2protkey(NULL, 0, tmpbuf, tmplen,
protkey, protkeylen, protkeytype, pflags);
pr_debug("cca_key2protkey()=%d\n", rc);
}
pr_debug("rc=%d\n", rc);
return rc;
}
static struct pkey_handler cca_handler = {
.module = THIS_MODULE,
.name = "PKEY CCA handler",
.is_supported_key = is_cca_key,
.is_supported_keytype = is_cca_keytype,
.key_to_protkey = cca_key2protkey,
.slowpath_key_to_protkey = cca_slowpath_key2protkey,
.gen_key = cca_gen_key,
.clr_to_key = cca_clr2key,
.verify_key = cca_verifykey,
.apqns_for_key = cca_apqns4key,
.apqns_for_keytype = cca_apqns4type,
};
/*
* Module init
*/
static int __init pkey_cca_init(void)
{
/* register this module as pkey handler for all the cca stuff */
return pkey_handler_register(&cca_handler);
}
/*
* Module exit
*/
static void __exit pkey_cca_exit(void)
{
/* unregister this module as pkey handler */
pkey_handler_unregister(&cca_handler);
}
module_init(pkey_cca_init);
module_exit(pkey_cca_exit);
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