[PATCH 1/4] RxRPC: Declare the security index constants symbolically

[PATCH 1/4] RxRPC: Declare the security index constants symbolically

[David Howells]

Declare the security index constants symbolically rather than just referring
to them numerically.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/linux/rxrpc.h |    7 +++++++
 net/rxrpc/ar-key.c    |    4 ++--
 net/rxrpc/rxkad.c     |    6 +++---
 3 files changed, 12 insertions(+), 5 deletions(-)


diff --git a/include/linux/rxrpc.h b/include/linux/rxrpc.h
index f7b826b..a53915c 100644
--- a/include/linux/rxrpc.h
+++ b/include/linux/rxrpc.h
@@ -58,5 +58,12 @@ struct sockaddr_rxrpc {
 #define RXRPC_SECURITY_AUTH	1	/* authenticated packets */
 #define RXRPC_SECURITY_ENCRYPT	2	/* encrypted packets */
 
+/*
+ * RxRPC security indices
+ */
+#define RXRPC_SECURITY_NONE	0	/* no security protocol */
+#define RXRPC_SECURITY_RXKAD	2	/* kaserver or kerberos 4 */
+#define RXRPC_SECURITY_RXGK	4	/* gssapi-based */
+#define RXRPC_SECURITY_RXK5	5	/* kerberos 5 */
 
 #endif /* _LINUX_RXRPC_H */
diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index ad8c7a7..b3d10e7 100644
--- a/net/rxrpc/ar-key.c
+++ b/net/rxrpc/ar-key.c
@@ -122,7 +122,7 @@ static int rxrpc_instantiate(struct key *key, const void *data, size_t datalen)
 		       tsec->ticket[6], tsec->ticket[7]);
 
 	ret = -EPROTONOSUPPORT;
-	if (tsec->security_index != 2)
+	if (tsec->security_index != RXRPC_SECURITY_RXKAD)
 		goto error;
 
 	key->type_data.x[0] = tsec->security_index;
@@ -308,7 +308,7 @@ int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
 	_debug("key %d", key_serial(key));
 
 	data.kver = 1;
-	data.tsec.security_index = 2;
+	data.tsec.security_index = RXRPC_SECURITY_RXKAD;
 	data.tsec.ticket_len = 0;
 	data.tsec.expiry = expiry;
 	data.tsec.kvno = 0;
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index ef8f910..acec762 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -42,7 +42,7 @@ struct rxkad_level2_hdr {
 	__be32	checksum;	/* decrypted data checksum */
 };
 
-MODULE_DESCRIPTION("RxRPC network protocol type-2 security (Kerberos)");
+MODULE_DESCRIPTION("RxRPC network protocol type-2 security (Kerberos 4)");
 MODULE_AUTHOR("Red Hat, Inc.");
 MODULE_LICENSE("GPL");
 
@@ -506,7 +506,7 @@ static int rxkad_verify_packet(const struct rxrpc_call *call,
 	if (!call->conn->cipher)
 		return 0;
 
-	if (sp->hdr.securityIndex != 2) {
+	if (sp->hdr.securityIndex != RXRPC_SECURITY_RXKAD) {
 		*_abort_code = RXKADINCONSISTENCY;
 		_leave(" = -EPROTO [not rxkad]");
 		return -EPROTO;
@@ -1122,7 +1122,7 @@ static void rxkad_clear(struct rxrpc_connection *conn)
 static struct rxrpc_security rxkad = {
 	.owner				= THIS_MODULE,
 	.name				= "rxkad",
-	.security_index			= RXKAD_VERSION,
+	.security_index			= RXRPC_SECURITY_RXKAD,
 	.init_connection_security	= rxkad_init_connection_security,
 	.prime_packet_security		= rxkad_prime_packet_security,
 	.secure_packet			= rxkad_secure_packet,

[PATCH 2/4] RxRPC: Allow key payloads to be passed in XDR form

[David Howells]

Allow add_key() and KEYCTL_INSTANTIATE to accept key payloads in XDR form as
described by openafs-1.4.10/src/auth/afs_token.xg.  This provides a way of
passing kaserver, Kerberos 4, Kerberos 5 and GSSAPI keys from userspace, and
allows for future expansion.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/keys/rxrpc-type.h |   55 ++++++++
 net/rxrpc/ar-internal.h   |   16 --
 net/rxrpc/ar-key.c        |  308 +++++++++++++++++++++++++++++++++++++++------
 net/rxrpc/ar-security.c   |    8 +
 net/rxrpc/rxkad.c         |   41 +++---
 5 files changed, 353 insertions(+), 75 deletions(-)


diff --git a/include/keys/rxrpc-type.h b/include/keys/rxrpc-type.h
index 7609365..c0d9121 100644
--- a/include/keys/rxrpc-type.h
+++ b/include/keys/rxrpc-type.h
@@ -21,4 +21,59 @@ extern struct key_type key_type_rxrpc;
 
 extern struct key *rxrpc_get_null_key(const char *);
 
+/*
+ * RxRPC key for Kerberos IV (type-2 security)
+ */
+struct rxkad_key {
+	u32	vice_id;
+	u32	start;			/* time at which ticket starts */
+	u32	expiry;			/* time at which ticket expires */
+	u32	kvno;			/* key version number */
+	u8	primary_flag;		/* T if key for primary cell for this user */
+	u16	ticket_len;		/* length of ticket[] */
+	u8	session_key[8];		/* DES session key */
+	u8	ticket[0];		/* the encrypted ticket */
+};
+
+/*
+ * list of tokens attached to an rxrpc key
+ */
+struct rxrpc_key_token {
+	u16	security_index;		/* RxRPC header security index */
+	struct rxrpc_key_token *next;	/* the next token in the list */
+	union {
+		struct rxkad_key *kad;
+	};
+};
+
+/*
+ * structure of raw payloads passed to add_key() or instantiate key
+ */
+struct rxrpc_key_data_v1 {
+	u32		kif_version;		/* 1 */
+	u16		security_index;
+	u16		ticket_length;
+	u32		expiry;			/* time_t */
+	u32		kvno;
+	u8		session_key[8];
+	u8		ticket[0];
+};
+
+/*
+ * AF_RXRPC key payload derived from XDR format
+ * - based on openafs-1.4.10/src/auth/afs_token.xg
+ */
+#define AFSTOKEN_LENGTH_MAX		16384	/* max payload size */
+#define AFSTOKEN_CELL_MAX		64	/* max cellname length */
+#define AFSTOKEN_MAX			8	/* max tokens per payload */
+#define AFSTOKEN_RK_TIX_MAX		12000	/* max RxKAD ticket size */
+#define AFSTOKEN_GK_KEY_MAX		64	/* max GSSAPI key size */
+#define AFSTOKEN_GK_TOKEN_MAX		16384	/* max GSSAPI token size */
+#define AFSTOKEN_K5_COMPONENTS_MAX	16	/* max K5 components */
+#define AFSTOKEN_K5_NAME_MAX		128	/* max K5 name length */
+#define AFSTOKEN_K5_REALM_MAX		64	/* max K5 realm name length */
+#define AFSTOKEN_K5_TIX_MAX		16384	/* max K5 ticket size */
+#define AFSTOKEN_K5_ADDRESSES_MAX	16	/* max K5 addresses */
+#define AFSTOKEN_K5_AUTHDATA_MAX	16	/* max K5 pieces of auth data */
+
 #endif /* _KEYS_RXRPC_TYPE_H */
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 3e7318c..46c6d88 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -402,22 +402,6 @@ struct rxrpc_call {
 };
 
 /*
- * RxRPC key for Kerberos (type-2 security)
- */
-struct rxkad_key {
-	u16	security_index;		/* RxRPC header security index */
-	u16	ticket_len;		/* length of ticket[] */
-	u32	expiry;			/* time at which expires */
-	u32	kvno;			/* key version number */
-	u8	session_key[8];		/* DES session key */
-	u8	ticket[0];		/* the encrypted ticket */
-};
-
-struct rxrpc_key_payload {
-	struct rxkad_key k;
-};
-
-/*
  * locally abort an RxRPC call
  */
 static inline void rxrpc_abort_call(struct rxrpc_call *call, u32 abort_code)
diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index b3d10e7..a3a7acb 100644
--- a/net/rxrpc/ar-key.c
+++ b/net/rxrpc/ar-key.c
@@ -17,6 +17,7 @@
 #include <linux/skbuff.h>
 #include <linux/key-type.h>
 #include <linux/crypto.h>
+#include <linux/ctype.h>
 #include <net/sock.h>
 #include <net/af_rxrpc.h>
 #include <keys/rxrpc-type.h>
@@ -55,6 +56,202 @@ struct key_type key_type_rxrpc_s = {
 };
 
 /*
+ * parse an RxKAD type XDR format token
+ * - the caller guarantees we have at least 4 words
+ */
+static int rxrpc_instantiate_xdr_rxkad(struct key *key, const __be32 *xdr,
+				       unsigned toklen)
+{
+	struct rxrpc_key_token *token;
+	size_t plen;
+	u32 tktlen;
+	int ret;
+
+	_enter(",{%x,%x,%x,%x},%u",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+	       toklen);
+
+	if (toklen <= 8 * 4)
+		return -EKEYREJECTED;
+	tktlen = ntohl(xdr[7]);
+	_debug("tktlen: %x", tktlen);
+	if (tktlen > AFSTOKEN_RK_TIX_MAX)
+		return -EKEYREJECTED;
+	if (8 * 4 + tktlen != toklen)
+		return -EKEYREJECTED;
+
+	plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
+	ret = key_payload_reserve(key, key->datalen + plen);
+	if (ret < 0)
+		return ret;
+
+	plen -= sizeof(*token);
+	token = kmalloc(sizeof(*token), GFP_KERNEL);
+	if (!token)
+		return -ENOMEM;
+
+	token->kad = kmalloc(plen, GFP_KERNEL);
+	if (!token->kad) {
+		kfree(token);
+		return -ENOMEM;
+	}
+
+	token->security_index	= RXRPC_SECURITY_RXKAD;
+	token->kad->ticket_len	= tktlen;
+	token->kad->vice_id	= ntohl(xdr[0]);
+	token->kad->kvno	= ntohl(xdr[1]);
+	token->kad->start	= ntohl(xdr[4]);
+	token->kad->expiry	= ntohl(xdr[5]);
+	token->kad->primary_flag = ntohl(xdr[6]);
+	memcpy(&token->kad->session_key, &xdr[2], 8);
+	memcpy(&token->kad->ticket, &xdr[8], tktlen);
+
+	_debug("SCIX: %u", token->security_index);
+	_debug("TLEN: %u", token->kad->ticket_len);
+	_debug("EXPY: %x", token->kad->expiry);
+	_debug("KVNO: %u", token->kad->kvno);
+	_debug("PRIM: %u", token->kad->primary_flag);
+	_debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
+	       token->kad->session_key[0], token->kad->session_key[1],
+	       token->kad->session_key[2], token->kad->session_key[3],
+	       token->kad->session_key[4], token->kad->session_key[5],
+	       token->kad->session_key[6], token->kad->session_key[7]);
+	if (token->kad->ticket_len >= 8)
+		_debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
+		       token->kad->ticket[0], token->kad->ticket[1],
+		       token->kad->ticket[2], token->kad->ticket[3],
+		       token->kad->ticket[4], token->kad->ticket[5],
+		       token->kad->ticket[6], token->kad->ticket[7]);
+
+	/* count the number of tokens attached */
+	key->type_data.x[0]++;
+
+	/* attach the data */
+	token->next = key->payload.data;
+	key->payload.data = token;
+	if (token->kad->expiry < key->expiry)
+		key->expiry = token->kad->expiry;
+
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * attempt to parse the data as the XDR format
+ * - the caller guarantees we have more than 7 words
+ */
+static int rxrpc_instantiate_xdr(struct key *key, const void *data, size_t datalen)
+{
+	const __be32 *xdr = data, *token;
+	const char *cp;
+	unsigned len, tmp, loop, ntoken, toklen, sec_ix;
+	int ret;
+
+	_enter(",{%x,%x,%x,%x},%zu",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+	       datalen);
+
+	if (datalen > AFSTOKEN_LENGTH_MAX)
+		goto not_xdr;
+
+	/* XDR is an array of __be32's */
+	if (datalen & 3)
+		goto not_xdr;
+
+	/* the flags should be 0 (the setpag bit must be handled by
+	 * userspace) */
+	if (ntohl(*xdr++) != 0)
+		goto not_xdr;
+	datalen -= 4;
+
+	/* check the cell name */
+	len = ntohl(*xdr++);
+	if (len < 1 || len > AFSTOKEN_CELL_MAX)
+		goto not_xdr;
+	datalen -= 4;
+	tmp = (len + 3) & ~3;
+	if (tmp > datalen)
+		goto not_xdr;
+
+	cp = (const char *) xdr;
+	for (loop = 0; loop < len; loop++)
+		if (!isprint(cp[loop]))
+			goto not_xdr;
+	if (len < tmp)
+		for (; loop < tmp; loop++)
+			if (cp[loop])
+				goto not_xdr;
+	_debug("cellname: [%u/%u] '%*.*s'",
+	       len, tmp, len, len, (const char *) xdr);
+	datalen -= tmp;
+	xdr += tmp >> 2;
+
+	/* get the token count */
+	if (datalen < 12)
+		goto not_xdr;
+	ntoken = ntohl(*xdr++);
+	datalen -= 4;
+	_debug("ntoken: %x", ntoken);
+	if (ntoken < 1 || ntoken > AFSTOKEN_MAX)
+		goto not_xdr;
+
+	/* check each token wrapper */
+	token = xdr;
+	loop = ntoken;
+	do {
+		if (datalen < 8)
+			goto not_xdr;
+		toklen = ntohl(*xdr++);
+		sec_ix = ntohl(*xdr);
+		datalen -= 4;
+		_debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);
+		if (toklen < 20 || toklen > datalen)
+			goto not_xdr;
+		datalen -= (toklen + 3) & ~3;
+		xdr += (toklen + 3) >> 2;
+
+	} while (--loop > 0);
+
+	_debug("remainder: %zu", datalen);
+	if (datalen != 0)
+		goto not_xdr;
+
+	/* okay: we're going to assume it's valid XDR format
+	 * - we ignore the cellname, relying on the key to be correctly named
+	 */
+	do {
+		xdr = token;
+		toklen = ntohl(*xdr++);
+		token = xdr + ((toklen + 3) >> 2);
+		sec_ix = ntohl(*xdr++);
+		toklen -= 4;
+
+		switch (sec_ix) {
+		case RXRPC_SECURITY_RXKAD:
+			ret = rxrpc_instantiate_xdr_rxkad(key, xdr, toklen);
+			if (ret != 0)
+				goto error;
+			break;
+
+		default:
+			ret = -EPROTONOSUPPORT;
+			goto error;
+		}
+
+	} while (--ntoken > 0);
+
+	_leave(" = 0");
+	return 0;
+
+not_xdr:
+	_leave(" = -EPROTO");
+	return -EPROTO;
+error:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
  * instantiate an rxrpc defined key
  * data should be of the form:
  *	OFFSET	LEN	CONTENT
@@ -70,8 +267,8 @@ struct key_type key_type_rxrpc_s = {
  */
 static int rxrpc_instantiate(struct key *key, const void *data, size_t datalen)
 {
-	const struct rxkad_key *tsec;
-	struct rxrpc_key_payload *upayload;
+	const struct rxrpc_key_data_v1 *v1;
+	struct rxrpc_key_token *token, **pp;
 	size_t plen;
 	u32 kver;
 	int ret;
@@ -82,6 +279,13 @@ static int rxrpc_instantiate(struct key *key, const void *data, size_t datalen)
 	if (!data && datalen == 0)
 		return 0;
 
+	/* determine if the XDR payload format is being used */
+	if (datalen > 7 * 4) {
+		ret = rxrpc_instantiate_xdr(key, data, datalen);
+		if (ret != -EPROTO)
+			return ret;
+	}
+
 	/* get the key interface version number */
 	ret = -EINVAL;
 	if (datalen <= 4 || !data)
@@ -98,53 +302,67 @@ static int rxrpc_instantiate(struct key *key, const void *data, size_t datalen)
 
 	/* deal with a version 1 key */
 	ret = -EINVAL;
-	if (datalen < sizeof(*tsec))
+	if (datalen < sizeof(*v1))
 		goto error;
 
-	tsec = data;
-	if (datalen != sizeof(*tsec) + tsec->ticket_len)
+	v1 = data;
+	if (datalen != sizeof(*v1) + v1->ticket_length)
 		goto error;
 
-	_debug("SCIX: %u", tsec->security_index);
-	_debug("TLEN: %u", tsec->ticket_len);
-	_debug("EXPY: %x", tsec->expiry);
-	_debug("KVNO: %u", tsec->kvno);
+	_debug("SCIX: %u", v1->security_index);
+	_debug("TLEN: %u", v1->ticket_length);
+	_debug("EXPY: %x", v1->expiry);
+	_debug("KVNO: %u", v1->kvno);
 	_debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
-	       tsec->session_key[0], tsec->session_key[1],
-	       tsec->session_key[2], tsec->session_key[3],
-	       tsec->session_key[4], tsec->session_key[5],
-	       tsec->session_key[6], tsec->session_key[7]);
-	if (tsec->ticket_len >= 8)
+	       v1->session_key[0], v1->session_key[1],
+	       v1->session_key[2], v1->session_key[3],
+	       v1->session_key[4], v1->session_key[5],
+	       v1->session_key[6], v1->session_key[7]);
+	if (v1->ticket_length >= 8)
 		_debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
-		       tsec->ticket[0], tsec->ticket[1],
-		       tsec->ticket[2], tsec->ticket[3],
-		       tsec->ticket[4], tsec->ticket[5],
-		       tsec->ticket[6], tsec->ticket[7]);
+		       v1->ticket[0], v1->ticket[1],
+		       v1->ticket[2], v1->ticket[3],
+		       v1->ticket[4], v1->ticket[5],
+		       v1->ticket[6], v1->ticket[7]);
 
 	ret = -EPROTONOSUPPORT;
-	if (tsec->security_index != RXRPC_SECURITY_RXKAD)
+	if (v1->security_index != RXRPC_SECURITY_RXKAD)
 		goto error;
 
-	key->type_data.x[0] = tsec->security_index;
-
-	plen = sizeof(*upayload) + tsec->ticket_len;
-	ret = key_payload_reserve(key, plen);
+	plen = sizeof(*token->kad) + v1->ticket_length;
+	ret = key_payload_reserve(key, plen + sizeof(*token));
 	if (ret < 0)
 		goto error;
 
 	ret = -ENOMEM;
-	upayload = kmalloc(plen, GFP_KERNEL);
-	if (!upayload)
+	token = kmalloc(sizeof(*token), GFP_KERNEL);
+	if (!token)
 		goto error;
+	token->kad = kmalloc(plen, GFP_KERNEL);
+	if (!token->kad)
+		goto error_free;
+
+	token->security_index		= RXRPC_SECURITY_RXKAD;
+	token->kad->ticket_len		= v1->ticket_length;
+	token->kad->expiry		= v1->expiry;
+	token->kad->kvno		= v1->kvno;
+	memcpy(&token->kad->session_key, &v1->session_key, 8);
+	memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
 
 	/* attach the data */
-	memcpy(&upayload->k, tsec, sizeof(*tsec));
-	memcpy(&upayload->k.ticket, (void *)tsec + sizeof(*tsec),
-	       tsec->ticket_len);
-	key->payload.data = upayload;
-	key->expiry = tsec->expiry;
+	key->type_data.x[0]++;
+
+	pp = (struct rxrpc_key_token **)&key->payload.data;
+	while (*pp)
+		pp = &(*pp)->next;
+	*pp = token;
+	if (token->kad->expiry < key->expiry)
+		key->expiry = token->kad->expiry;
+	token = NULL;
 	ret = 0;
 
+error_free:
+	kfree(token);
 error:
 	return ret;
 }
@@ -184,7 +402,22 @@ static int rxrpc_instantiate_s(struct key *key, const void *data,
  */
 static void rxrpc_destroy(struct key *key)
 {
-	kfree(key->payload.data);
+	struct rxrpc_key_token *token;
+
+	while ((token = key->payload.data)) {
+		key->payload.data = token->next;
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			kfree(token->kad);
+			break;
+		default:
+			printk(KERN_ERR "Unknown token type %x on rxrpc key\n",
+			       token->security_index);
+			BUG();
+		}
+
+		kfree(token);
+	}
 }
 
 /*
@@ -293,7 +526,7 @@ int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
 
 	struct {
 		u32 kver;
-		struct rxkad_key tsec;
+		struct rxrpc_key_data_v1 v1;
 	} data;
 
 	_enter("");
@@ -308,13 +541,12 @@ int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
 	_debug("key %d", key_serial(key));
 
 	data.kver = 1;
-	data.tsec.security_index = RXRPC_SECURITY_RXKAD;
-	data.tsec.ticket_len = 0;
-	data.tsec.expiry = expiry;
-	data.tsec.kvno = 0;
+	data.v1.security_index = RXRPC_SECURITY_RXKAD;
+	data.v1.ticket_length = 0;
+	data.v1.expiry = expiry;
+	data.v1.kvno = 0;
 
-	memcpy(&data.tsec.session_key, session_key,
-	       sizeof(data.tsec.session_key));
+	memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
 
 	ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
 	if (ret < 0)
diff --git a/net/rxrpc/ar-security.c b/net/rxrpc/ar-security.c
index dc62920..49b3cc3 100644
--- a/net/rxrpc/ar-security.c
+++ b/net/rxrpc/ar-security.c
@@ -16,6 +16,7 @@
 #include <linux/crypto.h>
 #include <net/sock.h>
 #include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
 #include "ar-internal.h"
 
 static LIST_HEAD(rxrpc_security_methods);
@@ -122,6 +123,7 @@ EXPORT_SYMBOL_GPL(rxrpc_unregister_security);
  */
 int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
 {
+	struct rxrpc_key_token *token;
 	struct rxrpc_security *sec;
 	struct key *key = conn->key;
 	int ret;
@@ -135,7 +137,11 @@ int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
 	if (ret < 0)
 		return ret;
 
-	sec = rxrpc_security_lookup(key->type_data.x[0]);
+	if (!key->payload.data)
+		return -EKEYREJECTED;
+	token = key->payload.data;
+
+	sec = rxrpc_security_lookup(token->security_index);
 	if (!sec)
 		return -EKEYREJECTED;
 	conn->security = sec;
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index acec762..713ac59 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -18,6 +18,7 @@
 #include <linux/ctype.h>
 #include <net/sock.h>
 #include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
 #define rxrpc_debug rxkad_debug
 #include "ar-internal.h"
 
@@ -59,14 +60,14 @@ static DEFINE_MUTEX(rxkad_ci_mutex);
  */
 static int rxkad_init_connection_security(struct rxrpc_connection *conn)
 {
-	struct rxrpc_key_payload *payload;
 	struct crypto_blkcipher *ci;
+	struct rxrpc_key_token *token;
 	int ret;
 
 	_enter("{%d},{%x}", conn->debug_id, key_serial(conn->key));
 
-	payload = conn->key->payload.data;
-	conn->security_ix = payload->k.security_index;
+	token = conn->key->payload.data;
+	conn->security_ix = token->security_index;
 
 	ci = crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
 	if (IS_ERR(ci)) {
@@ -75,8 +76,8 @@ static int rxkad_init_connection_security(struct rxrpc_connection *conn)
 		goto error;
 	}
 
-	if (crypto_blkcipher_setkey(ci, payload->k.session_key,
-				    sizeof(payload->k.session_key)) < 0)
+	if (crypto_blkcipher_setkey(ci, token->kad->session_key,
+				    sizeof(token->kad->session_key)) < 0)
 		BUG();
 
 	switch (conn->security_level) {
@@ -110,7 +111,7 @@ error:
  */
 static void rxkad_prime_packet_security(struct rxrpc_connection *conn)
 {
-	struct rxrpc_key_payload *payload;
+	struct rxrpc_key_token *token;
 	struct blkcipher_desc desc;
 	struct scatterlist sg[2];
 	struct rxrpc_crypt iv;
@@ -123,8 +124,8 @@ static void rxkad_prime_packet_security(struct rxrpc_connection *conn)
 	if (!conn->key)
 		return;
 
-	payload = conn->key->payload.data;
-	memcpy(&iv, payload->k.session_key, sizeof(iv));
+	token = conn->key->payload.data;
+	memcpy(&iv, token->kad->session_key, sizeof(iv));
 
 	desc.tfm = conn->cipher;
 	desc.info = iv.x;
@@ -197,7 +198,7 @@ static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
 					u32 data_size,
 					void *sechdr)
 {
-	const struct rxrpc_key_payload *payload;
+	const struct rxrpc_key_token *token;
 	struct rxkad_level2_hdr rxkhdr
 		__attribute__((aligned(8))); /* must be all on one page */
 	struct rxrpc_skb_priv *sp;
@@ -219,8 +220,8 @@ static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
 	rxkhdr.checksum = 0;
 
 	/* encrypt from the session key */
-	payload = call->conn->key->payload.data;
-	memcpy(&iv, payload->k.session_key, sizeof(iv));
+	token = call->conn->key->payload.data;
+	memcpy(&iv, token->kad->session_key, sizeof(iv));
 	desc.tfm = call->conn->cipher;
 	desc.info = iv.x;
 	desc.flags = 0;
@@ -400,7 +401,7 @@ static int rxkad_verify_packet_encrypt(const struct rxrpc_call *call,
 				       struct sk_buff *skb,
 				       u32 *_abort_code)
 {
-	const struct rxrpc_key_payload *payload;
+	const struct rxrpc_key_token *token;
 	struct rxkad_level2_hdr sechdr;
 	struct rxrpc_skb_priv *sp;
 	struct blkcipher_desc desc;
@@ -431,8 +432,8 @@ static int rxkad_verify_packet_encrypt(const struct rxrpc_call *call,
 	skb_to_sgvec(skb, sg, 0, skb->len);
 
 	/* decrypt from the session key */
-	payload = call->conn->key->payload.data;
-	memcpy(&iv, payload->k.session_key, sizeof(iv));
+	token = call->conn->key->payload.data;
+	memcpy(&iv, token->kad->session_key, sizeof(iv));
 	desc.tfm = call->conn->cipher;
 	desc.info = iv.x;
 	desc.flags = 0;
@@ -737,7 +738,7 @@ static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
 				      struct sk_buff *skb,
 				      u32 *_abort_code)
 {
-	const struct rxrpc_key_payload *payload;
+	const struct rxrpc_key_token *token;
 	struct rxkad_challenge challenge;
 	struct rxkad_response resp
 		__attribute__((aligned(8))); /* must be aligned for crypto */
@@ -778,7 +779,7 @@ static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
 	if (conn->security_level < min_level)
 		goto protocol_error;
 
-	payload = conn->key->payload.data;
+	token = conn->key->payload.data;
 
 	/* build the response packet */
 	memset(&resp, 0, sizeof(resp));
@@ -797,13 +798,13 @@ static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
 		(conn->channels[3] ? conn->channels[3]->call_id : 0);
 	resp.encrypted.inc_nonce = htonl(nonce + 1);
 	resp.encrypted.level = htonl(conn->security_level);
-	resp.kvno = htonl(payload->k.kvno);
-	resp.ticket_len = htonl(payload->k.ticket_len);
+	resp.kvno = htonl(token->kad->kvno);
+	resp.ticket_len = htonl(token->kad->ticket_len);
 
 	/* calculate the response checksum and then do the encryption */
 	rxkad_calc_response_checksum(&resp);
-	rxkad_encrypt_response(conn, &resp, &payload->k);
-	return rxkad_send_response(conn, &sp->hdr, &resp, &payload->k);
+	rxkad_encrypt_response(conn, &resp, token->kad);
+	return rxkad_send_response(conn, &sp->hdr, &resp, token->kad);
 
 protocol_error:
 	*_abort_code = abort_code;

[PATCH 3/4] RxRPC: Allow RxRPC keys to be read

[David Howells]

Allow RxRPC keys to be read.  This is to allow pioctl() to be implemented in
userspace.  RxRPC keys are read out in XDR format.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 net/rxrpc/ar-key.c |  109 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 109 insertions(+), 0 deletions(-)


diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index a3a7acb..bf4d623 100644
--- a/net/rxrpc/ar-key.c
+++ b/net/rxrpc/ar-key.c
@@ -29,6 +29,7 @@ static int rxrpc_instantiate_s(struct key *, const void *, size_t);
 static void rxrpc_destroy(struct key *);
 static void rxrpc_destroy_s(struct key *);
 static void rxrpc_describe(const struct key *, struct seq_file *);
+static long rxrpc_read(const struct key *, char __user *, size_t);
 
 /*
  * rxrpc defined keys take an arbitrary string as the description and an
@@ -40,6 +41,7 @@ struct key_type key_type_rxrpc = {
 	.match		= user_match,
 	.destroy	= rxrpc_destroy,
 	.describe	= rxrpc_describe,
+	.read		= rxrpc_read,
 };
 EXPORT_SYMBOL(key_type_rxrpc);
 
@@ -592,3 +594,110 @@ struct key *rxrpc_get_null_key(const char *keyname)
 	return key;
 }
 EXPORT_SYMBOL(rxrpc_get_null_key);
+
+/*
+ * read the contents of an rxrpc key
+ * - this returns the result in XDR form
+ */
+static long rxrpc_read(const struct key *key,
+		       char __user *buffer, size_t buflen)
+{
+	struct rxrpc_key_token *token;
+	size_t size, toksize;
+	__be32 __user *xdr;
+	u32 cnlen, tktlen, ntoks, zero;
+
+	_enter("");
+
+	/* we don't know what form we should return non-AFS keys in */
+	if (memcmp(key->description, "afs@", 4) != 0)
+		return -EOPNOTSUPP;
+	cnlen = strlen(key->description + 4);
+
+	/* AFS keys we return in XDR form, so we need to work out the size of
+	 * the XDR */
+	size = 2 * 4;	/* flags, cellname len */
+	size += (cnlen + 3) & ~3;	/* cellname */
+	size += 1 * 4;	/* token count */
+
+	ntoks = 0;
+	for (token = key->payload.data; token; token = token->next) {
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			size += 2 * 4;	/* length, security index (switch ID) */
+			size += 8 * 4;	/* viceid, kvno, key*2, begin, end,
+					 * primary, tktlen */
+			size += (token->kad->ticket_len + 3) & ~3; /* ticket */
+			ntoks++;
+			break;
+
+		default: /* can't encode */
+			break;
+		}
+	}
+
+	if (!buffer || buflen < size)
+		return size;
+
+	xdr = (__be32 __user *) buffer;
+	zero = 0;
+#define ENCODE(x)				\
+	do {					\
+		__be32 y = htonl(x);		\
+		if (put_user(y, xdr++) < 0)	\
+			goto fault;		\
+	} while(0)
+
+	ENCODE(0);	/* flags */
+	ENCODE(cnlen);	/* cellname length */
+	if (copy_to_user(xdr, key->description + 4, cnlen) != 0)
+		goto fault;
+	if (cnlen & 3 &&
+	    copy_to_user((u8 *)xdr + cnlen, &zero, 4 - (cnlen & 3)) != 0)
+		goto fault;
+	xdr += (cnlen + 3) >> 2;
+	ENCODE(ntoks);	/* token count */
+
+	for (token = key->payload.data; token; token = token->next) {
+		toksize = 1 * 4;	/* sec index */
+
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			toksize += 8 * 4;
+			toksize += (token->kad->ticket_len + 3) & ~3;
+			ENCODE(toksize);
+			ENCODE(token->security_index);
+			ENCODE(token->kad->vice_id);
+			ENCODE(token->kad->kvno);
+			if (copy_to_user(xdr, token->kad->session_key, 8) != 0)
+				goto fault;
+			xdr += 8 >> 2;
+			ENCODE(token->kad->start);
+			ENCODE(token->kad->expiry);
+			ENCODE(token->kad->primary_flag);
+			tktlen = token->kad->ticket_len;
+			ENCODE(tktlen);
+			if (copy_to_user(xdr, token->kad->ticket, tktlen) != 0)
+				goto fault;
+			if (tktlen & 3 &&
+			    copy_to_user((u8 *)xdr + tktlen, &zero,
+					 4 - (tktlen & 3)) != 0)
+				goto fault;
+			xdr += (tktlen + 3) >> 2;
+			break;
+
+		default:
+			break;
+		}
+	}
+
+#undef ENCODE
+
+	ASSERTCMP((char __user *) xdr - buffer, ==, size);
+	_leave(" = %zu", size);
+	return size;
+
+fault:
+	_leave(" = -EFAULT");
+	return -EFAULT;
+}

[PATCH 4/4] RxRPC: Parse security index 5 keys (Kerberos 5)

[David Howells]

Parse RxRPC security index 5 type keys (Kerberos 5 tokens).

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/keys/rxrpc-type.h |   52 ++++
 net/rxrpc/ar-key.c        |  577 ++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 589 insertions(+), 40 deletions(-)


diff --git a/include/keys/rxrpc-type.h b/include/keys/rxrpc-type.h
index c0d9121..5eb2357 100644
--- a/include/keys/rxrpc-type.h
+++ b/include/keys/rxrpc-type.h
@@ -36,6 +36,54 @@ struct rxkad_key {
 };
 
 /*
+ * Kerberos 5 principal
+ *	name/name/name@realm
+ */
+struct krb5_principal {
+	u8	n_name_parts;		/* N of parts of the name part of the principal */
+	char	**name_parts;		/* parts of the name part of the principal */
+	char	*realm;			/* parts of the realm part of the principal */
+};
+
+/*
+ * Kerberos 5 tagged data
+ */
+struct krb5_tagged_data {
+	/* for tag value, see /usr/include/krb5/krb5.h
+	 * - KRB5_AUTHDATA_* for auth data
+	 * - 
+	 */
+	int32_t		tag;
+	uint32_t	data_len;
+	u8		*data;
+};
+
+/*
+ * RxRPC key for Kerberos V (type-5 security)
+ */
+struct rxk5_key {
+	uint64_t		authtime;	/* time at which auth token generated */
+	uint64_t		starttime;	/* time at which auth token starts */
+	uint64_t		endtime;	/* time at which auth token expired */
+	uint64_t		renew_till;	/* time to which auth token can be renewed */
+	int32_t			is_skey;	/* T if ticket is encrypted in another ticket's
+						 * skey */
+	int32_t			flags;		/* mask of TKT_FLG_* bits (krb5/krb5.h) */
+	struct krb5_principal	client;		/* client principal name */
+	struct krb5_principal	server;		/* server principal name */
+	uint16_t		ticket_len;	/* length of ticket */
+	uint16_t		ticket2_len;	/* length of second ticket */
+	u8			n_authdata;	/* number of authorisation data elements */
+	u8			n_addresses;	/* number of addresses */
+	struct krb5_tagged_data	session;	/* session data; tag is enctype */
+	struct krb5_tagged_data *addresses;	/* addresses */
+	u8			*ticket;	/* krb5 ticket */
+	u8			*ticket2;	/* second krb5 ticket, if related to ticket (via
+						 * DUPLICATE-SKEY or ENC-TKT-IN-SKEY) */
+	struct krb5_tagged_data *authdata;	/* authorisation data */
+};
+
+/*
  * list of tokens attached to an rxrpc key
  */
 struct rxrpc_key_token {
@@ -43,6 +91,7 @@ struct rxrpc_key_token {
 	struct rxrpc_key_token *next;	/* the next token in the list */
 	union {
 		struct rxkad_key *kad;
+		struct rxk5_key *k5;
 	};
 };
 
@@ -64,8 +113,11 @@ struct rxrpc_key_data_v1 {
  * - based on openafs-1.4.10/src/auth/afs_token.xg
  */
 #define AFSTOKEN_LENGTH_MAX		16384	/* max payload size */
+#define AFSTOKEN_STRING_MAX		256	/* max small string length */
+#define AFSTOKEN_DATA_MAX		64	/* max small data length */
 #define AFSTOKEN_CELL_MAX		64	/* max cellname length */
 #define AFSTOKEN_MAX			8	/* max tokens per payload */
+#define AFSTOKEN_BDATALN_MAX		16384	/* max big data length */
 #define AFSTOKEN_RK_TIX_MAX		12000	/* max RxKAD ticket size */
 #define AFSTOKEN_GK_KEY_MAX		64	/* max GSSAPI key size */
 #define AFSTOKEN_GK_TOKEN_MAX		16384	/* max GSSAPI token size */
diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index bf4d623..44836f6 100644
--- a/net/rxrpc/ar-key.c
+++ b/net/rxrpc/ar-key.c
@@ -64,7 +64,7 @@ struct key_type key_type_rxrpc_s = {
 static int rxrpc_instantiate_xdr_rxkad(struct key *key, const __be32 *xdr,
 				       unsigned toklen)
 {
-	struct rxrpc_key_token *token;
+	struct rxrpc_key_token *token, **pptoken;
 	size_t plen;
 	u32 tktlen;
 	int ret;
@@ -129,13 +129,398 @@ static int rxrpc_instantiate_xdr_rxkad(struct key *key, const __be32 *xdr,
 	key->type_data.x[0]++;
 
 	/* attach the data */
-	token->next = key->payload.data;
-	key->payload.data = token;
+	for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
+	     *pptoken;
+	     pptoken = &(*pptoken)->next)
+		continue;
+	*pptoken = token;
+	if (token->kad->expiry < key->expiry)
+		key->expiry = token->kad->expiry;
+
+	_leave(" = 0");
+	return 0;
+}
+
+static void rxrpc_free_krb5_principal(struct krb5_principal *princ)
+{
+	int loop;
+
+	if (princ->name_parts) {
+		for (loop = princ->n_name_parts - 1; loop >= 0; loop--)
+			kfree(princ->name_parts[loop]);
+		kfree(princ->name_parts);
+	}
+	kfree(princ->realm);
+}
+
+static void rxrpc_free_krb5_tagged(struct krb5_tagged_data *td)
+{
+	kfree(td->data);
+}
+
+/*
+ * free up an RxK5 token
+ */
+static void rxrpc_rxk5_free(struct rxk5_key *rxk5)
+{
+	int loop;
+
+	rxrpc_free_krb5_principal(&rxk5->client);
+	rxrpc_free_krb5_principal(&rxk5->server);
+	rxrpc_free_krb5_tagged(&rxk5->session);
+
+	if (rxk5->addresses) {
+		for (loop = rxk5->n_addresses - 1; loop >= 0; loop--)
+			rxrpc_free_krb5_tagged(&rxk5->addresses[loop]);
+		kfree(rxk5->addresses);
+	}
+	if (rxk5->authdata) {
+		for (loop = rxk5->n_authdata - 1; loop >= 0; loop--)
+			rxrpc_free_krb5_tagged(&rxk5->authdata[loop]);
+		kfree(rxk5->authdata);
+	}
+
+	kfree(rxk5->ticket);
+	kfree(rxk5->ticket2);
+	kfree(rxk5);
+}
+
+/*
+ * extract a krb5 principal
+ */
+static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
+				       const __be32 **_xdr,
+				       unsigned *_toklen)
+{
+	const __be32 *xdr = *_xdr;
+	unsigned toklen = *_toklen, n_parts, loop, tmp;
+
+	/* there must be at least one name, and at least #names+1 length
+	 * words */
+	if (toklen <= 12)
+		return -EINVAL;
+
+	_enter(",{%x,%x,%x},%u",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), toklen);
+
+	n_parts = ntohl(*xdr++);
+	toklen -= 4;
+	if (n_parts <= 0 || n_parts > AFSTOKEN_K5_COMPONENTS_MAX)
+		return -EINVAL;
+	princ->n_name_parts = n_parts;
+
+	if (toklen <= (n_parts + 1) * 4)
+		return -EINVAL;
+
+	princ->name_parts = kcalloc(sizeof(char *), n_parts, GFP_KERNEL);
+	if (!princ->name_parts)
+		return -ENOMEM;
+
+	for (loop = 0; loop < n_parts; loop++) {
+		if (toklen < 4)
+			return -EINVAL;
+		tmp = ntohl(*xdr++);
+		toklen -= 4;
+		if (tmp <= 0 || tmp > AFSTOKEN_STRING_MAX)
+			return -EINVAL;
+		if (tmp > toklen)
+			return -EINVAL;
+		princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
+		if (!princ->name_parts[loop])
+			return -ENOMEM;
+		memcpy(princ->name_parts[loop], xdr, tmp);
+		princ->name_parts[loop][tmp] = 0;
+		tmp = (tmp + 3) & ~3;
+		toklen -= tmp;
+		xdr += tmp >> 2;
+	}
+
+	if (toklen < 4)
+		return -EINVAL;
+	tmp = ntohl(*xdr++);
+	toklen -= 4;
+	if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
+		return -EINVAL;
+	if (tmp > toklen)
+		return -EINVAL;
+	princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
+	if (!princ->realm)
+		return -ENOMEM;
+	memcpy(princ->realm, xdr, tmp);
+	princ->realm[tmp] = 0;
+	tmp = (tmp + 3) & ~3;
+	toklen -= tmp;
+	xdr += tmp >> 2;
+
+	_debug("%s/...@%s", princ->name_parts[0], princ->realm);
+
+	*_xdr = xdr;
+	*_toklen = toklen;
+	_leave(" = 0 [toklen=%u]", toklen);
+	return 0;
+}
+
+/*
+ * extract a piece of krb5 tagged data
+ */
+static int rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data *td,
+					 size_t max_data_size,
+					 const __be32 **_xdr,
+					 unsigned *_toklen)
+{
+	const __be32 *xdr = *_xdr;
+	unsigned toklen = *_toklen, len;
+
+	/* there must be at least one tag and one length word */
+	if (toklen <= 8)
+		return -EINVAL;
+
+	_enter(",%zu,{%x,%x},%u",
+	       max_data_size, ntohl(xdr[0]), ntohl(xdr[1]), toklen);
+
+	td->tag = ntohl(*xdr++);
+	len = ntohl(*xdr++);
+	toklen -= 8;
+	if (len > max_data_size)
+		return -EINVAL;
+	td->data_len = len;
+
+	if (len > 0) {
+		td->data = kmalloc(len, GFP_KERNEL);
+		if (!td->data)
+			return -ENOMEM;
+		memcpy(td->data, xdr, len);
+		len = (len + 3) & ~3;
+		toklen -= len;
+		xdr += len >> 2;
+	}
+
+	_debug("tag %x len %x", td->tag, td->data_len);
+
+	*_xdr = xdr;
+	*_toklen = toklen;
+	_leave(" = 0 [toklen=%u]", toklen);
+	return 0;
+}
+
+/*
+ * extract an array of tagged data
+ */
+static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
+					  u8 *_n_elem,
+					  u8 max_n_elem,
+					  size_t max_elem_size,
+					  const __be32 **_xdr,
+					  unsigned *_toklen)
+{
+	struct krb5_tagged_data *td;
+	const __be32 *xdr = *_xdr;
+	unsigned toklen = *_toklen, n_elem, loop;
+	int ret;
+
+	/* there must be at least one count */
+	if (toklen < 4)
+		return -EINVAL;
+
+	_enter(",,%u,%zu,{%x},%u",
+	       max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
+
+	n_elem = ntohl(*xdr++);
+	toklen -= 4;
+	if (n_elem < 0 || n_elem > max_n_elem)
+		return -EINVAL;
+	*_n_elem = n_elem;
+	if (n_elem > 0) {
+		if (toklen <= (n_elem + 1) * 4)
+			return -EINVAL;
+
+		_debug("n_elem %d", n_elem);
+
+		td = kcalloc(sizeof(struct krb5_tagged_data), n_elem,
+			     GFP_KERNEL);
+		if (!td)
+			return -ENOMEM;
+		*_td = td;
+
+		for (loop = 0; loop < n_elem; loop++) {
+			ret = rxrpc_krb5_decode_tagged_data(&td[loop],
+							    max_elem_size,
+							    &xdr, &toklen);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	*_xdr = xdr;
+	*_toklen = toklen;
+	_leave(" = 0 [toklen=%u]", toklen);
+	return 0;
+}
+
+/*
+ * extract a krb5 ticket
+ */
+static int rxrpc_krb5_decode_ticket(u8 **_ticket, uint16_t *_tktlen,
+				    const __be32 **_xdr, unsigned *_toklen)
+{
+	const __be32 *xdr = *_xdr;
+	unsigned toklen = *_toklen, len;
+
+	/* there must be at least one length word */
+	if (toklen <= 4)
+		return -EINVAL;
+
+	_enter(",{%x},%u", ntohl(xdr[0]), toklen);
+
+	len = ntohl(*xdr++);
+	toklen -= 4;
+	if (len > AFSTOKEN_K5_TIX_MAX)
+		return -EINVAL;
+	*_tktlen = len;
+
+	_debug("ticket len %u", len);
+
+	if (len > 0) {
+		*_ticket = kmalloc(len, GFP_KERNEL);
+		if (!*_ticket)
+			return -ENOMEM;
+		memcpy(*_ticket, xdr, len);
+		len = (len + 3) & ~3;
+		toklen -= len;
+		xdr += len >> 2;
+	}
+
+	*_xdr = xdr;
+	*_toklen = toklen;
+	_leave(" = 0 [toklen=%u]", toklen);
+	return 0;
+}
+
+/*
+ * parse an RxK5 type XDR format token
+ * - the caller guarantees we have at least 4 words
+ */
+static int rxrpc_instantiate_xdr_rxk5(struct key *key, const __be32 *xdr,
+				      unsigned toklen)
+{
+	struct rxrpc_key_token *token, **pptoken;
+	struct rxk5_key *rxk5;
+	const __be32 *end_xdr = xdr + (toklen >> 2);
+	int ret;
+
+	_enter(",{%x,%x,%x,%x},%u",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+	       toklen);
+
+	/* reserve some payload space for this subkey - the length of the token
+	 * is a reasonable approximation */
+	ret = key_payload_reserve(key, key->datalen + toklen);
+	if (ret < 0)
+		return ret;
+
+	token = kzalloc(sizeof(*token), GFP_KERNEL);
+	if (!token)
+		return -ENOMEM;
+
+	rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
+	if (!rxk5) {
+		kfree(token);
+		return -ENOMEM;
+	}
+
+	token->security_index = RXRPC_SECURITY_RXK5;
+	token->k5 = rxk5;
+
+	/* extract the principals */
+	ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+	ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+
+	/* extract the session key and the encoding type (the tag field ->
+	 * ENCTYPE_xxx) */
+	ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
+					    &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+
+	if (toklen < 4 * 8 + 2 * 4)
+		goto inval;
+	rxk5->authtime	= be64_to_cpup((const __be64 *) xdr);
+	xdr += 2;
+	rxk5->starttime	= be64_to_cpup((const __be64 *) xdr);
+	xdr += 2;
+	rxk5->endtime	= be64_to_cpup((const __be64 *) xdr);
+	xdr += 2;
+	rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
+	xdr += 2;
+	rxk5->is_skey = ntohl(*xdr++);
+	rxk5->flags = ntohl(*xdr++);
+	toklen -= 4 * 8 + 2 * 4;
+
+	_debug("times: a=%llx s=%llx e=%llx rt=%llx",
+	       rxk5->authtime, rxk5->starttime, rxk5->endtime,
+	       rxk5->renew_till);
+	_debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
+
+	/* extract the permitted client addresses */
+	ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
+					     &rxk5->n_addresses,
+					     AFSTOKEN_K5_ADDRESSES_MAX,
+					     AFSTOKEN_DATA_MAX,
+					     &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+
+	ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+	/* extract the tickets */
+	ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
+				       &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+	ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
+				       &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+
+	ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+	/* extract the typed auth data */
+	ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
+					     &rxk5->n_authdata,
+					     AFSTOKEN_K5_AUTHDATA_MAX,
+					     AFSTOKEN_BDATALN_MAX,
+					     &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+
+	ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+	if (toklen != 0)
+		goto inval;
+
+	/* attach the payload to the key */
+	for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
+	     *pptoken;
+	     pptoken = &(*pptoken)->next)
+		continue;
+	*pptoken = token;
 	if (token->kad->expiry < key->expiry)
 		key->expiry = token->kad->expiry;
 
 	_leave(" = 0");
 	return 0;
+
+inval:
+	ret = -EINVAL;
+error:
+	rxrpc_rxk5_free(rxk5);
+	kfree(token);
+	_leave(" = %d", ret);
+	return ret;
 }
 
 /*
@@ -228,6 +613,8 @@ static int rxrpc_instantiate_xdr(struct key *key, const void *data, size_t datal
 		sec_ix = ntohl(*xdr++);
 		toklen -= 4;
 
+		_debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
+
 		switch (sec_ix) {
 		case RXRPC_SECURITY_RXKAD:
 			ret = rxrpc_instantiate_xdr_rxkad(key, xdr, toklen);
@@ -235,6 +622,12 @@ static int rxrpc_instantiate_xdr(struct key *key, const void *data, size_t datal
 				goto error;
 			break;
 
+		case RXRPC_SECURITY_RXK5:
+			ret = rxrpc_instantiate_xdr_rxk5(key, xdr, toklen);
+			if (ret != 0)
+				goto error;
+			break;
+
 		default:
 			ret = -EPROTONOSUPPORT;
 			goto error;
@@ -412,6 +805,10 @@ static void rxrpc_destroy(struct key *key)
 		case RXRPC_SECURITY_RXKAD:
 			kfree(token->kad);
 			break;
+		case RXRPC_SECURITY_RXK5:
+			if (token->k5)
+				rxrpc_rxk5_free(token->k5);
+			break;
 		default:
 			printk(KERN_ERR "Unknown token type %x on rxrpc key\n",
 			       token->security_index);
@@ -602,10 +999,13 @@ EXPORT_SYMBOL(rxrpc_get_null_key);
 static long rxrpc_read(const struct key *key,
 		       char __user *buffer, size_t buflen)
 {
-	struct rxrpc_key_token *token;
-	size_t size, toksize;
-	__be32 __user *xdr;
-	u32 cnlen, tktlen, ntoks, zero;
+	const struct rxrpc_key_token *token;
+	const struct krb5_principal *princ;
+	size_t size;
+	__be32 __user *xdr, *oldxdr;
+	u32 cnlen, toksize, ntoks, tok, zero;
+	u16 toksizes[AFSTOKEN_MAX];
+	int loop;
 
 	_enter("");
 
@@ -614,28 +1014,68 @@ static long rxrpc_read(const struct key *key,
 		return -EOPNOTSUPP;
 	cnlen = strlen(key->description + 4);
 
+#define RND(X) (((X) + 3) & ~3)
+
 	/* AFS keys we return in XDR form, so we need to work out the size of
 	 * the XDR */
 	size = 2 * 4;	/* flags, cellname len */
-	size += (cnlen + 3) & ~3;	/* cellname */
+	size += RND(cnlen);	/* cellname */
 	size += 1 * 4;	/* token count */
 
 	ntoks = 0;
 	for (token = key->payload.data; token; token = token->next) {
+		toksize = 4;	/* sec index */
+
 		switch (token->security_index) {
 		case RXRPC_SECURITY_RXKAD:
-			size += 2 * 4;	/* length, security index (switch ID) */
-			size += 8 * 4;	/* viceid, kvno, key*2, begin, end,
-					 * primary, tktlen */
-			size += (token->kad->ticket_len + 3) & ~3; /* ticket */
-			ntoks++;
+			toksize += 8 * 4;	/* viceid, kvno, key*2, begin,
+						 * end, primary, tktlen */
+			toksize += RND(token->kad->ticket_len);
 			break;
 
-		default: /* can't encode */
+		case RXRPC_SECURITY_RXK5:
+			princ = &token->k5->client;
+			toksize += 4 + princ->n_name_parts * 4;
+			for (loop = 0; loop < princ->n_name_parts; loop++)
+				toksize += RND(strlen(princ->name_parts[loop]));
+			toksize += 4 + RND(strlen(princ->realm));
+
+			princ = &token->k5->server;
+			toksize += 4 + princ->n_name_parts * 4;
+			for (loop = 0; loop < princ->n_name_parts; loop++)
+				toksize += RND(strlen(princ->name_parts[loop]));
+			toksize += 4 + RND(strlen(princ->realm));
+
+			toksize += 8 + RND(token->k5->session.data_len);
+
+			toksize += 4 * 8 + 2 * 4;
+
+			toksize += 4 + token->k5->n_addresses * 8;
+			for (loop = 0; loop < token->k5->n_addresses; loop++)
+				toksize += RND(token->k5->addresses[loop].data_len);
+
+			toksize += 4 + RND(token->k5->ticket_len);
+			toksize += 4 + RND(token->k5->ticket2_len);
+
+			toksize += 4 + token->k5->n_authdata * 8;
+			for (loop = 0; loop < token->k5->n_authdata; loop++)
+				toksize += RND(token->k5->authdata[loop].data_len);
 			break;
+
+		default: /* we have a ticket we can't encode */
+			BUG();
+			continue;
 		}
+
+		_debug("token[%u]: toksize=%u", ntoks, toksize);
+		ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
+
+		toksizes[ntoks++] = toksize;
+		size += toksize + 4; /* each token has a length word */
 	}
 
+#undef RND
+
 	if (!buffer || buflen < size)
 		return size;
 
@@ -647,52 +1087,109 @@ static long rxrpc_read(const struct key *key,
 		if (put_user(y, xdr++) < 0)	\
 			goto fault;		\
 	} while(0)
+#define ENCODE_DATA(l, s)						\
+	do {								\
+		u32 _l = (l);						\
+		ENCODE(l);						\
+		if (copy_to_user(xdr, (s), _l) != 0)			\
+			goto fault;					\
+		if (_l & 3 &&						\
+		    copy_to_user((u8 *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
+			goto fault;					\
+		xdr += (_l + 3) >> 2;					\
+	} while(0)
+#define ENCODE64(x)					\
+	do {						\
+		__be64 y = cpu_to_be64(x);		\
+		if (copy_to_user(xdr, &y, 8) != 0)	\
+			goto fault;			\
+		xdr += 8 >> 2;				\
+	} while(0)
+#define ENCODE_STR(s)				\
+	do {					\
+		const char *_s = (s);		\
+		ENCODE_DATA(strlen(_s), _s);	\
+	} while(0)
 
-	ENCODE(0);	/* flags */
-	ENCODE(cnlen);	/* cellname length */
-	if (copy_to_user(xdr, key->description + 4, cnlen) != 0)
-		goto fault;
-	if (cnlen & 3 &&
-	    copy_to_user((u8 *)xdr + cnlen, &zero, 4 - (cnlen & 3)) != 0)
-		goto fault;
-	xdr += (cnlen + 3) >> 2;
-	ENCODE(ntoks);	/* token count */
+	ENCODE(0);					/* flags */
+	ENCODE_DATA(cnlen, key->description + 4);	/* cellname */
+	ENCODE(ntoks);
 
+	tok = 0;
 	for (token = key->payload.data; token; token = token->next) {
-		toksize = 1 * 4;	/* sec index */
+		toksize = toksizes[tok++];
+		ENCODE(toksize);
+		oldxdr = xdr;
+		ENCODE(token->security_index);
 
 		switch (token->security_index) {
 		case RXRPC_SECURITY_RXKAD:
-			toksize += 8 * 4;
-			toksize += (token->kad->ticket_len + 3) & ~3;
-			ENCODE(toksize);
-			ENCODE(token->security_index);
 			ENCODE(token->kad->vice_id);
 			ENCODE(token->kad->kvno);
-			if (copy_to_user(xdr, token->kad->session_key, 8) != 0)
-				goto fault;
-			xdr += 8 >> 2;
+			ENCODE_DATA(8, token->kad->session_key);
 			ENCODE(token->kad->start);
 			ENCODE(token->kad->expiry);
 			ENCODE(token->kad->primary_flag);
-			tktlen = token->kad->ticket_len;
-			ENCODE(tktlen);
-			if (copy_to_user(xdr, token->kad->ticket, tktlen) != 0)
-				goto fault;
-			if (tktlen & 3 &&
-			    copy_to_user((u8 *)xdr + tktlen, &zero,
-					 4 - (tktlen & 3)) != 0)
-				goto fault;
-			xdr += (tktlen + 3) >> 2;
+			ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
+			break;
+
+		case RXRPC_SECURITY_RXK5:
+			princ = &token->k5->client;
+			ENCODE(princ->n_name_parts);
+			for (loop = 0; loop < princ->n_name_parts; loop++)
+				ENCODE_STR(princ->name_parts[loop]);
+			ENCODE_STR(princ->realm);
+
+			princ = &token->k5->server;
+			ENCODE(princ->n_name_parts);
+			for (loop = 0; loop < princ->n_name_parts; loop++)
+				ENCODE_STR(princ->name_parts[loop]);
+			ENCODE_STR(princ->realm);
+
+			ENCODE(token->k5->session.tag);
+			ENCODE_DATA(token->k5->session.data_len,
+				    token->k5->session.data);
+
+			ENCODE64(token->k5->authtime);
+			ENCODE64(token->k5->starttime);
+			ENCODE64(token->k5->endtime);
+			ENCODE64(token->k5->renew_till);
+			ENCODE(token->k5->is_skey);
+			ENCODE(token->k5->flags);
+
+			ENCODE(token->k5->n_addresses);
+			for (loop = 0; loop < token->k5->n_addresses; loop++) {
+				ENCODE(token->k5->addresses[loop].tag);
+				ENCODE_DATA(token->k5->addresses[loop].data_len,
+					    token->k5->addresses[loop].data);
+			}
+
+			ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
+			ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
+
+			ENCODE(token->k5->n_authdata);
+			for (loop = 0; loop < token->k5->n_authdata; loop++) {
+				ENCODE(token->k5->authdata[loop].tag);
+				ENCODE_DATA(token->k5->authdata[loop].data_len,
+					    token->k5->authdata[loop].data);
+			}
 			break;
 
 		default:
+			BUG();
 			break;
 		}
+
+		ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
+			  toksize);
 	}
 
+#undef ENCODE_STR
+#undef ENCODE_DATA
+#undef ENCODE64
 #undef ENCODE
 
+	ASSERTCMP(tok, ==, ntoks);
 	ASSERTCMP((char __user *) xdr - buffer, ==, size);
 	_leave(" = %zu", size);
 	return size;