RxRPC: Parse security index 5 keys (Kerberos 5)

Parse RxRPC security index 5 type keys (Kerberos 5 tokens).
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/keys/rxrpc-type.h

@@ -35,6 +35,54 @@ struct rxkad_key {
 	u8	ticket[0];		/* the encrypted ticket */
 };
 
+/*
+ * 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
  */
@@ -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 */