s390/pkey: do not use struct pkey_protkey

This is an internal rework of the pkey code to not use the
struct pkey_protkey internal any more. This struct has a hard
coded protected key buffer with MAXPROTKEYSIZE = 64 bytes.
However, with support for ECC protected key, this limit is
too short and thus this patch reworks all the internal code
to use the triple u8 *protkey, u32 protkeylen, u32 protkeytype
instead. So the ioctl which still has to deal with this struct
coming from userspace and/or provided to userspace invoke all
the internal functions now with the triple instead of passing
a pointer to struct pkey_protkey.

Also the struct pkey_clrkey has been internally replaced in
a similar way. This struct also has a hard coded clear key
buffer of MAXCLRKEYSIZE = 32 bytes and thus is not usable with
e.g. ECC clear key material.

This is a transparent rework for userspace applications using
the pkey API. The internal kernel API used by the PAES crypto
ciphers has been adapted to this change to make it possible
to provide ECC protected keys via this interface in the future.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

arch/s390/crypto/paes_s390.c

@@ -5,7 +5,7 @@
  * s390 implementation of the AES Cipher Algorithm with protected keys.
  *
  * s390 Version:
- *   Copyright IBM Corp. 2017,2020
+ *   Copyright IBM Corp. 2017, 2023
  *   Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  *		Harald Freudenberger <freude@de.ibm.com>
  */
@@ -132,7 +132,8 @@ static inline int __paes_keyblob2pkey(struct key_blob *kb,
 		if (i > 0 && ret == -EAGAIN && in_task())
 			if (msleep_interruptible(1000))
 				return -EINTR;
-		ret = pkey_keyblob2pkey(kb->key, kb->keylen, pk);
+		ret = pkey_keyblob2pkey(kb->key, kb->keylen,
+					pk->protkey, &pk->len, &pk->type);
 		if (ret == 0)
 			break;
 	}
@@ -145,6 +146,7 @@ static inline int __paes_convert_key(struct s390_paes_ctx *ctx)
 	int ret;
 	struct pkey_protkey pkey;
 
+	pkey.len = sizeof(pkey.protkey);
 	ret = __paes_keyblob2pkey(&ctx->kb, &pkey);
 	if (ret)
 		return ret;
@@ -414,6 +416,9 @@ static inline int __xts_paes_convert_key(struct s390_pxts_ctx *ctx)
 {
 	struct pkey_protkey pkey0, pkey1;
 
+	pkey0.len = sizeof(pkey0.protkey);
+	pkey1.len = sizeof(pkey1.protkey);
+
 	if (__paes_keyblob2pkey(&ctx->kb[0], &pkey0) ||
 	    __paes_keyblob2pkey(&ctx->kb[1], &pkey1))
 		return -EINVAL;

arch/s390/include/asm/pkey.h

@@ -2,7 +2,7 @@
 /*
  * Kernelspace interface to the pkey device driver
  *
- * Copyright IBM Corp. 2016,2019
+ * Copyright IBM Corp. 2016, 2023
  *
  * Author: Harald Freudenberger <freude@de.ibm.com>
  *
@@ -23,6 +23,6 @@
  * @return 0 on success, negative errno value on failure
  */
 int pkey_keyblob2pkey(const u8 *key, u32 keylen,
-		      struct pkey_protkey *protkey);
+		      u8 *protkey, u32 *protkeylen, u32 *protkeytype);
 
 #endif /* _KAPI_PKEY_H */