pkey: Move keytype check from pkey api to handler

The PKEY_VERIFYPROTK ioctl takes data from user-space and verifies the
contained protected key. While checking the integrity of the ioctl
request structure is the responsibility of the generic pkey_api code,
the verification of the contained protected key is the responsibility
of the pkey handler.

The keytype verification (based on the calculated bitsize of the key)
is part of the protected key verification and therefore the
responsibility of the pkey handler (which already verifies
it). Therefore the keytype verification is removed from the generic
pkey_api code.

As the calculation of the key bitsize is currently wrong, the removal
of the keytype check in pkey_api also removes this wrong
calculation. For this reason, the commit is flagged with the Fixes:
tag.

Cc: stable@kernel.org # 6.12+
Fixes: 8fcc231 ("s390/pkey: Introduce pkey base with handler registry and handler modules")
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

Author: holger-dengler

drivers/s390/crypto/pkey_api.c

@@ -327,7 +327,6 @@ static int pkey_ioctl_verifyprotk(struct pkey_verifyprotk __user *uvp)
 {
 	struct pkey_verifyprotk kvp;
 	struct protaeskeytoken *t;
-	u32 keytype;
 	u8 *tmpbuf;
 	int rc;
 
@@ -341,14 +340,6 @@ static int pkey_ioctl_verifyprotk(struct pkey_verifyprotk __user *uvp)
 		return -EINVAL;
 	}
 
-	keytype = pkey_aes_bitsize_to_keytype(8 * kvp.protkey.len);
-	if (!keytype) {
-		PKEY_DBF_ERR("%s unknown/unsupported protkey length %u\n",
-			     __func__, kvp.protkey.len);
-		memzero_explicit(&kvp, sizeof(kvp));
-		return -EINVAL;
-	}
-
 	/* build a 'protected key token' from the raw protected key */
 	tmpbuf = kzalloc(sizeof(*t), GFP_KERNEL);
 	if (!tmpbuf) {
@@ -358,7 +349,7 @@ static int pkey_ioctl_verifyprotk(struct pkey_verifyprotk __user *uvp)
 	t = (struct protaeskeytoken *)tmpbuf;
 	t->type = TOKTYPE_NON_CCA;
 	t->version = TOKVER_PROTECTED_KEY;
-	t->keytype = keytype;
+	t->keytype = kvp.protkey.type;
 	t->len = kvp.protkey.len;
 	memcpy(t->protkey, kvp.protkey.protkey, kvp.protkey.len);