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>

1 files changed, 62 insertions, 15 deletions

diff --git a/arch/s390/include/uapi/asm/pkey.h b/arch/s390/include/uapi/asm/pkey.h
index d27d7d329263..7349e96d28a0 100644
--- a/arch/s390/include/uapi/asm/pkey.h
+++ b/arch/s390/include/uapi/asm/pkey.h
@@ -35,12 +35,16 @@
 #define PKEY_KEYTYPE_AES_128		      1
 #define PKEY_KEYTYPE_AES_192		      2
 #define PKEY_KEYTYPE_AES_256		      3
+#define PKEY_KEYTYPE_ECC		      4
 
 /* the newer ioctls use a pkey_key_type enum for type information */
 enum pkey_key_type {
 	PKEY_TYPE_CCA_DATA   = (__u32) 1,
 	PKEY_TYPE_CCA_CIPHER = (__u32) 2,
 	PKEY_TYPE_EP11	     = (__u32) 3,
+	PKEY_TYPE_CCA_ECC    = (__u32) 0x1f,
+	PKEY_TYPE_EP11_AES   = (__u32) 6,
+	PKEY_TYPE_EP11_ECC   = (__u32) 7,
 };
 
 /* the newer ioctls use a pkey_key_size enum for key size information */
@@ -89,6 +93,20 @@ struct pkey_clrkey {
 };
 
 /*
+ * EP11 key blobs of type PKEY_TYPE_EP11_AES and PKEY_TYPE_EP11_ECC
+ * are ep11 blobs prepended by this header:
+ */
+struct ep11kblob_header {
+	__u8  type;	/* always 0x00 */
+	__u8  hver;	/* header version,  currently needs to be 0x00 */
+	__u16 len;	/* total length in bytes (including this header) */
+	__u8  version;	/* PKEY_TYPE_EP11_AES or PKEY_TYPE_EP11_ECC */
+	__u8  res0;	/* unused */
+	__u16 bitlen;	/* clear key bit len, 0 for unknown */
+	__u8  res1[8];	/* unused */
+} __packed;
+
+/*
  * Generate CCA AES secure key.
  */
 struct pkey_genseck {
@@ -304,7 +322,7 @@ struct pkey_verifykey2 {
 #define PKEY_VERIFYKEY2 _IOWR(PKEY_IOCTL_MAGIC, 0x17, struct pkey_verifykey2)
 
 /*
- * Transform a key blob (of any type) into a protected key, version 2.
+ * Transform a key blob into a protected key, version 2.
  * There needs to be a list of apqns given with at least one entry in there.
  * All apqns in the list need to be exact apqns, 0xFFFF as ANY card or domain
  * is not supported. The implementation walks through the list of apqns and
@@ -313,6 +331,8 @@ struct pkey_verifykey2 {
  * list is tried until success (return 0) or the end of the list is reached
  * (return -1 with errno ENODEV). You may use the PKEY_APQNS4K ioctl to
  * generate a list of apqns based on the key.
+ * Deriving ECC protected keys from ECC secure keys is not supported with
+ * this ioctl, use PKEY_KBLOB2PROTK3 for this purpose.
  */
 struct pkey_kblob2pkey2 {
 	__u8 __user *key;	     /* in: pointer to key blob		   */
@@ -326,17 +346,17 @@ struct pkey_kblob2pkey2 {
 /*
  * Build a list of APQNs based on a key blob given.
  * Is able to find out which type of secure key is given (CCA AES secure
- * key, CCA AES cipher key or EP11 AES key) and tries to find all matching
- * crypto cards based on the MKVP and maybe other criterias (like CCA AES
- * cipher keys need a CEX5C or higher, EP11 keys with BLOB_PKEY_EXTRACTABLE
- * need a CEX7 and EP11 api version 4). The list of APQNs is further filtered
- * by the key's mkvp which needs to match to either the current mkvp (CCA and
- * EP11) or the alternate mkvp (old mkvp, CCA adapters only) 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. At least one of the matching flags needs to be given.
+ * key, CCA AES cipher key, CCA ECC private key, EP11 AES key, EP11 ECC private
+ * key) and tries to find all matching crypto cards based on the MKVP and maybe
+ * other criterias (like CCA AES cipher keys need a CEX5C or higher, EP11 keys
+ * with BLOB_PKEY_EXTRACTABLE need a CEX7 and EP11 api version 4). The list of
+ * APQNs is further filtered by the key's mkvp which needs to match to either
+ * the current mkvp (CCA and EP11) or the alternate mkvp (old mkvp, CCA adapters
+ * only) 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. At least one of the matching flags needs to be given.
  * The flags argument for EP11 keys has no further action and is currently
  * ignored (but needs to be given as PKEY_FLAGS_MATCH_CUR_MKVP) as there is only
  * the wkvp from the key to match against the apqn's wkvp.
@@ -365,9 +385,10 @@ struct pkey_apqns4key {
  * 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
+ * cipher key) the first 8 bytes of cur_mkvp refer to the current AES mkvp value
+ * of the apqn and the first 8 bytes of the alt_mkvp refer to the old AES mkvp.
+ * For CCA ECC keys it is similar but the match is against the APKA current/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
@@ -397,4 +418,30 @@ struct pkey_apqns4keytype {
 };
 #define PKEY_APQNS4KT _IOWR(PKEY_IOCTL_MAGIC, 0x1C, struct pkey_apqns4keytype)
 
+/*
+ * Transform a key blob into a protected key, version 3.
+ * The difference to version 2 of this ioctl is that the protected key
+ * buffer is now explicitly and not within a struct pkey_protkey any more.
+ * So this ioctl is also able to handle EP11 and CCA ECC secure keys and
+ * provide ECC protected keys.
+ * There needs to be a list of apqns given with at least one entry in there.
+ * All apqns in the list need to be exact apqns, 0xFFFF as ANY card or domain
+ * is not supported. The implementation walks through the list of apqns and
+ * tries to send the request to each 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). You may use the PKEY_APQNS4K ioctl to
+ * generate a list of apqns based on the key.
+ */
+struct pkey_kblob2pkey3 {
+	__u8 __user *key;	     /* in: pointer to key blob		   */
+	__u32 keylen;		     /* in: key blob size		   */
+	struct pkey_apqn __user *apqns; /* in: ptr to list of apqn targets */
+	__u32 apqn_entries;	     /* in: # of apqn target list entries  */
+	__u32 pkeytype;		/* out: prot key type (enum pkey_key_type) */
+	__u32 pkeylen;	 /* in/out: size of pkey buffer/actual len of pkey */
+	__u8 __user *pkey;		 /* in: pkey blob buffer space ptr */
+};
+#define PKEY_KBLOB2PROTK3 _IOWR(PKEY_IOCTL_MAGIC, 0x1D, struct pkey_kblob2pkey3)
+
 #endif /* _UAPI_PKEY_H */