s390/zcrypt_ep11misc: support API ordinal 6 with empty pin-blob

Secure execution guest environments require an empty pinblob in all
key generation and unwrap requests. Empty pinblobs are only available
in EP11 API ordinal 6 or higher.

Add an empty pinblob to key generation and unwrap requests, if the AP
secure binding facility is available. In all other cases, stay with
the empty pin tag (no pinblob) and the current API ordinals.

The EP11 API ordinal also needs to be considered when the pkey module
tries to figure out the list of eligible cards for key operations
with protected keys in secure execution environment.

These changes are transparent to userspace but required for running
an secure execution guest with handling key generate and key derive
(e.g. secure key to protected key) correct. Especially using EP11
secure keys with the kernel dm-crypt layer requires this patch.

Co-developed-by: Harald Freudenberger <[e-mail]>
Signed-off-by: Harald Freudenberger <[e-mail]>
Signed-off-by: Holger Dengler <[e-mail]>
Reviewed-by: Ingo Franzki <[e-mail]>
Signed-off-by: Heiko Carstens <[e-mail]>

drivers/s390/crypto/ap_bus.c

···
 }
 
 /*
+ * ap_is_se_guest(): Check for SE guest with AP pass-through support.
+ */
+bool ap_is_se_guest(void)
+{
+	return is_prot_virt_guest() && ap_sb_available();
+}
+EXPORT_SYMBOL(ap_is_se_guest);
+
+/*
  * ap_fetch_qci_info(): Fetch cryptographic config info
  *
  * Returns the ap configuration info fetched via PQAP(QCI).

drivers/s390/crypto/ap_bus.h

···
 
 void *ap_airq_ptr(void);
 int ap_sb_available(void);
+bool ap_is_se_guest(void);
 void ap_wait(enum ap_sm_wait wait);
 void ap_request_timeout(struct timer_list *t);
 void ap_bus_force_rescan(void);

drivers/s390/crypto/pkey_api.c

···
 
 	/* build a list of apqns suitable for ep11 keys with cpacf support */
 	rc = ep11_findcard2(&apqns, &nr_apqns, 0xFFFF, 0xFFFF,
-			    ZCRYPT_CEX7, EP11_API_V, NULL);
+			    ZCRYPT_CEX7,
+			    ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4,
+			    NULL);
 	if (rc)
 		goto out;
 
···
 
 	/* build a list of apqns suitable for this key */
 	rc = ep11_findcard2(&apqns, &nr_apqns, 0xFFFF, 0xFFFF,
-			    ZCRYPT_CEX7, EP11_API_V,
+			    ZCRYPT_CEX7,
+			    ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4,
 			    ep11_kb_wkvp(key, keylen));
 	if (rc)
 		goto out;
···
 	} else if (hdr->type == TOKTYPE_NON_CCA &&
 		   hdr->version == TOKVER_EP11_AES) {
 		struct ep11keyblob *kb = (struct ep11keyblob *)key;
+		int api;
 
 		rc = ep11_check_aes_key(debug_info, 3, key, keylen, 1);
 		if (rc)
···
 		if (ksize)
 			*ksize = kb->head.bitlen;
 
+		api = ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4;
 		rc = ep11_findcard2(&_apqns, &_nr_apqns, *cardnr, *domain,
-				    ZCRYPT_CEX7, EP11_API_V,
+				    ZCRYPT_CEX7, api,
 				    ep11_kb_wkvp(key, keylen));
 		if (rc)
 			goto out;
···
 	} else if (hdr->type == TOKTYPE_NON_CCA &&
 		   hdr->version == TOKVER_EP11_AES_WITH_HEADER) {
 		struct ep11kblob_header *kh = (struct ep11kblob_header *)key;
+		int api;
 
 		rc = ep11_check_aes_key_with_hdr(debug_info, 3,
 						 key, keylen, 1);
···
 		if (ksize)
 			*ksize = kh->bitlen;
 
+		api = ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4;
 		rc = ep11_findcard2(&_apqns, &_nr_apqns, *cardnr, *domain,
-				    ZCRYPT_CEX7, EP11_API_V,
+				    ZCRYPT_CEX7, api,
 				    ep11_kb_wkvp(key, keylen));
 		if (rc)
 			goto out;
···
 			return -EINVAL;
 		if (kb->attr & EP11_BLOB_PKEY_EXTRACTABLE) {
 			minhwtype = ZCRYPT_CEX7;
-			api = EP11_API_V;
+			api = ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4;
 		}
 		rc = ep11_findcard2(&_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
 				    minhwtype, api, kb->wkvp);
···
 			return -EINVAL;
 		if (kb->attr & EP11_BLOB_PKEY_EXTRACTABLE) {
 			minhwtype = ZCRYPT_CEX7;
-			api = EP11_API_V;
+			api = ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4;
 		}
 		rc = ep11_findcard2(&_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
 				    minhwtype, api, kb->wkvp);
···
 		   ktype == PKEY_TYPE_EP11_AES ||
 		   ktype == PKEY_TYPE_EP11_ECC) {
 		u8 *wkvp = NULL;
+		int api;
 
 		if (flags & PKEY_FLAGS_MATCH_CUR_MKVP)
 			wkvp = cur_mkvp;
+		api = ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4;
 		rc = ep11_findcard2(&_apqns, &_nr_apqns, 0xFFFF, 0xFFFF,
-				    ZCRYPT_CEX7, EP11_API_V, wkvp);
+				    ZCRYPT_CEX7, api, wkvp);
 		if (rc)
 			goto out;
 
···
 
 	/* build a list of apqns able to generate an cipher key */
 	rc = ep11_findcard2(&apqns, &nr_apqns, 0xFFFF, 0xFFFF,
-			    ZCRYPT_CEX7, EP11_API_V, NULL);
+			    ZCRYPT_CEX7,
+			    ap_is_se_guest() ? EP11_API_V6 : EP11_API_V4,
+			    NULL);
 	if (rc)
 		return rc;
 

drivers/s390/crypto/zcrypt_ep11misc.c

···
 #define DEBUG_WARN(...) ZCRYPT_DBF(DBF_WARN, ##__VA_ARGS__)
 #define DEBUG_ERR(...)	ZCRYPT_DBF(DBF_ERR, ##__VA_ARGS__)
 
+#define EP11_PINBLOB_V1_BYTES 56
+
 /* default iv used here */
 static const u8 def_iv[16] = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
 			       0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff };
···
 	struct ep11_cprb *req = NULL, *rep = NULL;
 	struct ep11_target_dev target;
 	struct ep11_urb *urb = NULL;
-	int api = 1, rc = -ENOMEM;
+	int api = EP11_API_V1, rc = -ENOMEM;
 
 	/* request cprb and payload */
 	req = alloc_cprb(sizeof(struct ep11_info_req_pl));
···
 		u32 attr_bool_bits;
 		u32 attr_val_len_type;
 		u32 attr_val_len_value;
-		u8  pin_tag;
-		u8  pin_len;
+		/* followed by empty pin tag or empty pinblob tag */
 	} __packed * req_pl;
 	struct keygen_rep_pl {
 		struct pl_head head;
···
 		u8  data[512];
 	} __packed * rep_pl;
 	struct ep11_cprb *req = NULL, *rep = NULL;
+	size_t req_pl_size, pinblob_size = 0;
 	struct ep11_target_dev target;
 	struct ep11_urb *urb = NULL;
 	int api, rc = -ENOMEM;
+	u8 *p;
 
 	switch (keybitsize) {
 	case 128:
···
 	}
 
 	/* request cprb and payload */
-	req = alloc_cprb(sizeof(struct keygen_req_pl));
+	api = (!keygenflags || keygenflags & 0x00200000) ?
+		EP11_API_V4 : EP11_API_V1;
+	if (ap_is_se_guest()) {
+		/*
+		 * genkey within SE environment requires API ordinal 6
+		 * with empty pinblob
+		 */
+		api = EP11_API_V6;
+		pinblob_size = EP11_PINBLOB_V1_BYTES;
+	}
+	req_pl_size = sizeof(struct keygen_req_pl) + ASN1TAGLEN(pinblob_size);
+	req = alloc_cprb(req_pl_size);
 	if (!req)
 		goto out;
 	req_pl = (struct keygen_req_pl *)(((u8 *)req) + sizeof(*req));
-	api = (!keygenflags || keygenflags & 0x00200000) ? 4 : 1;
-	prep_head(&req_pl->head, sizeof(*req_pl), api, 21); /* GenerateKey */
+	prep_head(&req_pl->head, req_pl_size, api, 21); /* GenerateKey */
 	req_pl->var_tag = 0x04;
 	req_pl->var_len = sizeof(u32);
 	req_pl->keybytes_tag = 0x04;
···
 	req_pl->attr_bool_bits = keygenflags ? keygenflags : KEY_ATTR_DEFAULTS;
 	req_pl->attr_val_len_type = 0x00000161; /* CKA_VALUE_LEN */
 	req_pl->attr_val_len_value = keybitsize / 8;
-	req_pl->pin_tag = 0x04;
+	p = ((u8 *)req_pl) + sizeof(*req_pl);
+	/* pin tag */
+	*p++ = 0x04;
+	*p++ = pinblob_size;
 
 	/* reply cprb and payload */
 	rep = alloc_cprb(sizeof(struct keygen_rep_pl));
···
 	target.ap_id = card;
 	target.dom_id = domain;
 	prep_urb(urb, &target, 1,
-		 req, sizeof(*req) + sizeof(*req_pl),
+		 req, sizeof(*req) + req_pl_size,
 		 rep, sizeof(*rep) + sizeof(*rep_pl));
 
 	rc = zcrypt_send_ep11_cprb(urb);
···
 	struct ep11_target_dev target;
 	struct ep11_urb *urb = NULL;
 	size_t req_pl_size, rep_pl_size;
-	int n, api = 1, rc = -ENOMEM;
+	int n, api = EP11_API_V1, rc = -ENOMEM;
 	u8 *p;
 
 	/* the simple asn1 coding used has length limits */
···
 		 * maybe followed by iv data
 		 * followed by kek tag + kek blob
 		 * followed by empty mac tag
-		 * followed by empty pin tag
+		 * followed by empty pin tag or empty pinblob tag
 		 * followed by encryted key tag + bytes
 		 */
 	} __packed * req_pl;
···
 		u8  data[512];
 	} __packed * rep_pl;
 	struct ep11_cprb *req = NULL, *rep = NULL;
+	size_t req_pl_size, pinblob_size = 0;
 	struct ep11_target_dev target;
 	struct ep11_urb *urb = NULL;
-	size_t req_pl_size;
 	int api, rc = -ENOMEM;
 	u8 *p;
 
 	/* request cprb and payload */
+	api = (!keygenflags || keygenflags & 0x00200000) ?
+		EP11_API_V4 : EP11_API_V1;
+	if (ap_is_se_guest()) {
+		/*
+		 * unwrap within SE environment requires API ordinal 6
+		 * with empty pinblob
+		 */
+		api = EP11_API_V6;
+		pinblob_size = EP11_PINBLOB_V1_BYTES;
+	}
 	req_pl_size = sizeof(struct uw_req_pl) + (iv ? 16 : 0)
-		+ ASN1TAGLEN(keksize) + 4 + ASN1TAGLEN(enckeysize);
+		+ ASN1TAGLEN(keksize) + ASN1TAGLEN(0)
+		+ ASN1TAGLEN(pinblob_size) + ASN1TAGLEN(enckeysize);
 	req = alloc_cprb(req_pl_size);
 	if (!req)
 		goto out;
 	req_pl = (struct uw_req_pl *)(((u8 *)req) + sizeof(*req));
-	api = (!keygenflags || keygenflags & 0x00200000) ? 4 : 1;
 	prep_head(&req_pl->head, req_pl_size, api, 34); /* UnwrapKey */
 	req_pl->attr_tag = 0x04;
 	req_pl->attr_len = 7 * sizeof(u32);
···
 	/* empty mac key tag */
 	*p++ = 0x04;
 	*p++ = 0;
-	/* empty pin tag */
+	/* pin tag */
 	*p++ = 0x04;
-	*p++ = 0;
+	*p++ = pinblob_size;
+	p += pinblob_size;
 	/* encrypted key value tag and bytes */
 	p += asn1tag_write(p, 0x04, enckey, enckeysize);
 
···
 	if (!mech || mech == 0x80060001)
 		req->flags |= 0x20; /* CPACF_WRAP needs special bit */
 	req_pl = (struct wk_req_pl *)(((u8 *)req) + sizeof(*req));
-	api = (!mech || mech == 0x80060001) ? 4 : 1; /* CKM_IBM_CPACF_WRAP */
+	api = (!mech || mech == 0x80060001) ? /* CKM_IBM_CPACF_WRAP */
+		EP11_API_V4 : EP11_API_V1;
 	prep_head(&req_pl->head, req_pl_size, api, 33); /* WrapKey */
 	req_pl->var_tag = 0x04;
 	req_pl->var_len = sizeof(u32);

drivers/s390/crypto/zcrypt_ep11misc.h

···
 #include <asm/zcrypt.h>
 #include <asm/pkey.h>
 
-#define EP11_API_V 4  /* highest known and supported EP11 API version */
+#define EP11_API_V1 1  /* min EP11 API, default if no higher api required */
+#define EP11_API_V4 4  /* supported EP11 API for the ep11misc cprbs */
+#define EP11_API_V6 6  /* min EP11 API for some cprbs in SE environment */
 #define EP11_STRUCT_MAGIC 0x1234
 #define EP11_BLOB_PKEY_EXTRACTABLE 0x00200000