Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1248 insertions, 0 deletions

diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c
new file mode 100644
index 000000000..9be6b35fd
--- /dev/null
+++ b/net/rxrpc/key.c
@@ -0,0 +1,1248 @@
+/* RxRPC key management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * RxRPC keys should have a description of describing their purpose:
+ *	"afs@CAMBRIDGE.REDHAT.COM>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <crypto/skcipher.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/key-type.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include <keys/user-type.h>
+#include "ar-internal.h"
+
+static int rxrpc_vet_description_s(const char *);
+static int rxrpc_preparse(struct key_preparsed_payload *);
+static int rxrpc_preparse_s(struct key_preparsed_payload *);
+static void rxrpc_free_preparse(struct key_preparsed_payload *);
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
+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 *, size_t);
+
+/*
+ * rxrpc defined keys take an arbitrary string as the description and an
+ * arbitrary blob of data as the payload
+ */
+struct key_type key_type_rxrpc = {
+	.name		= "rxrpc",
+	.preparse	= rxrpc_preparse,
+	.free_preparse	= rxrpc_free_preparse,
+	.instantiate	= generic_key_instantiate,
+	.destroy	= rxrpc_destroy,
+	.describe	= rxrpc_describe,
+	.read		= rxrpc_read,
+};
+EXPORT_SYMBOL(key_type_rxrpc);
+
+/*
+ * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
+ * description and an 8-byte decryption key as the payload
+ */
+struct key_type key_type_rxrpc_s = {
+	.name		= "rxrpc_s",
+	.vet_description = rxrpc_vet_description_s,
+	.preparse	= rxrpc_preparse_s,
+	.free_preparse	= rxrpc_free_preparse_s,
+	.instantiate	= generic_key_instantiate,
+	.destroy	= rxrpc_destroy_s,
+	.describe	= rxrpc_describe,
+};
+
+/*
+ * Vet the description for an RxRPC server key
+ */
+static int rxrpc_vet_description_s(const char *desc)
+{
+	unsigned long num;
+	char *p;
+
+	num = simple_strtoul(desc, &p, 10);
+	if (*p != ':' || num > 65535)
+		return -EINVAL;
+	num = simple_strtoul(p + 1, &p, 10);
+	if (*p || num < 1 || num > 255)
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ * parse an RxKAD type XDR format token
+ * - the caller guarantees we have at least 4 words
+ */
+static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep,
+				    size_t datalen,
+				    const __be32 *xdr, unsigned int toklen)
+{
+	struct rxrpc_key_token *token, **pptoken;
+	time64_t expiry;
+	size_t plen;
+	u32 tktlen;
+
+	_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 (toklen < 8 * 4 + tktlen)
+		return -EKEYREJECTED;
+
+	plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
+	prep->quotalen = datalen + plen;
+
+	plen -= sizeof(*token);
+	token = kzalloc(sizeof(*token), GFP_KERNEL);
+	if (!token)
+		return -ENOMEM;
+
+	token->kad = kzalloc(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 */
+	prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
+
+	/* attach the data */
+	for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
+	     *pptoken;
+	     pptoken = &(*pptoken)->next)
+		continue;
+	*pptoken = token;
+	expiry = rxrpc_u32_to_time64(token->kad->expiry);
+	if (expiry < prep->expiry)
+		prep->expiry = 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 int *_toklen)
+{
+	const __be32 *xdr = *_xdr;
+	unsigned int toklen = *_toklen, n_parts, loop, tmp, paddedlen;
+
+	/* 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(n_parts, sizeof(char *), 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;
+		paddedlen = (tmp + 3) & ~3;
+		if (paddedlen > 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;
+		toklen -= paddedlen;
+		xdr += paddedlen >> 2;
+	}
+
+	if (toklen < 4)
+		return -EINVAL;
+	tmp = ntohl(*xdr++);
+	toklen -= 4;
+	if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
+		return -EINVAL;
+	paddedlen = (tmp + 3) & ~3;
+	if (paddedlen > toklen)
+		return -EINVAL;
+	princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
+	if (!princ->realm)
+		return -ENOMEM;
+	memcpy(princ->realm, xdr, tmp);
+	princ->realm[tmp] = 0;
+	toklen -= paddedlen;
+	xdr += paddedlen >> 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 int *_toklen)
+{
+	const __be32 *xdr = *_xdr;
+	unsigned int toklen = *_toklen, len, paddedlen;
+
+	/* 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;
+	paddedlen = (len + 3) & ~3;
+	if (paddedlen > toklen)
+		return -EINVAL;
+	td->data_len = len;
+
+	if (len > 0) {
+		td->data = kmemdup(xdr, len, GFP_KERNEL);
+		if (!td->data)
+			return -ENOMEM;
+		toklen -= paddedlen;
+		xdr += paddedlen >> 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 int *_toklen)
+{
+	struct krb5_tagged_data *td;
+	const __be32 *xdr = *_xdr;
+	unsigned int 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 > 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(n_elem, sizeof(struct krb5_tagged_data),
+			     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, u16 *_tktlen,
+				    const __be32 **_xdr, unsigned int *_toklen)
+{
+	const __be32 *xdr = *_xdr;
+	unsigned int toklen = *_toklen, len, paddedlen;
+
+	/* 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;
+	paddedlen = (len + 3) & ~3;
+	if (paddedlen > toklen)
+		return -EINVAL;
+	*_tktlen = len;
+
+	_debug("ticket len %u", len);
+
+	if (len > 0) {
+		*_ticket = kmemdup(xdr, len, GFP_KERNEL);
+		if (!*_ticket)
+			return -ENOMEM;
+		toklen -= paddedlen;
+		xdr += paddedlen >> 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_preparse_xdr_rxk5(struct key_preparsed_payload *prep,
+				   size_t datalen,
+				   const __be32 *xdr, unsigned int toklen)
+{
+	struct rxrpc_key_token *token, **pptoken;
+	struct rxk5_key *rxk5;
+	const __be32 *end_xdr = xdr + (toklen >> 2);
+	time64_t expiry;
+	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 */
+	prep->quotalen = datalen + toklen;
+
+	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 */
+	for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
+	     *pptoken;
+	     pptoken = &(*pptoken)->next)
+		continue;
+	*pptoken = token;
+	expiry = rxrpc_u32_to_time64(token->k5->endtime);
+	if (expiry < prep->expiry)
+		prep->expiry = expiry;
+
+	_leave(" = 0");
+	return 0;
+
+inval:
+	ret = -EINVAL;
+error:
+	rxrpc_rxk5_free(rxk5);
+	kfree(token);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * attempt to parse the data as the XDR format
+ * - the caller guarantees we have more than 7 words
+ */
+static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)
+{
+	const __be32 *xdr = prep->data, *token;
+	const char *cp;
+	unsigned int len, paddedlen, loop, ntoken, toklen, sec_ix;
+	size_t datalen = prep->datalen;
+	int ret;
+
+	_enter(",{%x,%x,%x,%x},%zu",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+	       prep->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;
+	paddedlen = (len + 3) & ~3;
+	if (paddedlen > datalen)
+		goto not_xdr;
+
+	cp = (const char *) xdr;
+	for (loop = 0; loop < len; loop++)
+		if (!isprint(cp[loop]))
+			goto not_xdr;
+	for (; loop < paddedlen; loop++)
+		if (cp[loop])
+			goto not_xdr;
+	_debug("cellname: [%u/%u] '%*.*s'",
+	       len, paddedlen, len, len, (const char *) xdr);
+	datalen -= paddedlen;
+	xdr += paddedlen >> 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);
+		paddedlen = (toklen + 3) & ~3;
+		if (toklen < 20 || toklen > datalen || paddedlen > datalen)
+			goto not_xdr;
+		datalen -= paddedlen;
+		xdr += paddedlen >> 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;
+
+		_debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
+
+		switch (sec_ix) {
+		case RXRPC_SECURITY_RXKAD:
+			ret = rxrpc_preparse_xdr_rxkad(prep, datalen, xdr, toklen);
+			if (ret != 0)
+				goto error;
+			break;
+
+		case RXRPC_SECURITY_RXK5:
+			ret = rxrpc_preparse_xdr_rxk5(prep, datalen, 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;
+}
+
+/*
+ * Preparse an rxrpc defined key.
+ *
+ * Data should be of the form:
+ *	OFFSET	LEN	CONTENT
+ *	0	4	key interface version number
+ *	4	2	security index (type)
+ *	6	2	ticket length
+ *	8	4	key expiry time (time_t)
+ *	12	4	kvno
+ *	16	8	session key
+ *	24	[len]	ticket
+ *
+ * if no data is provided, then a no-security key is made
+ */
+static int rxrpc_preparse(struct key_preparsed_payload *prep)
+{
+	const struct rxrpc_key_data_v1 *v1;
+	struct rxrpc_key_token *token, **pp;
+	time64_t expiry;
+	size_t plen;
+	u32 kver;
+	int ret;
+
+	_enter("%zu", prep->datalen);
+
+	/* handle a no-security key */
+	if (!prep->data && prep->datalen == 0)
+		return 0;
+
+	/* determine if the XDR payload format is being used */
+	if (prep->datalen > 7 * 4) {
+		ret = rxrpc_preparse_xdr(prep);
+		if (ret != -EPROTO)
+			return ret;
+	}
+
+	/* get the key interface version number */
+	ret = -EINVAL;
+	if (prep->datalen <= 4 || !prep->data)
+		goto error;
+	memcpy(&kver, prep->data, sizeof(kver));
+	prep->data += sizeof(kver);
+	prep->datalen -= sizeof(kver);
+
+	_debug("KEY I/F VERSION: %u", kver);
+
+	ret = -EKEYREJECTED;
+	if (kver != 1)
+		goto error;
+
+	/* deal with a version 1 key */
+	ret = -EINVAL;
+	if (prep->datalen < sizeof(*v1))
+		goto error;
+
+	v1 = prep->data;
+	if (prep->datalen != sizeof(*v1) + v1->ticket_length)
+		goto error;
+
+	_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",
+	       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",
+		       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 (v1->security_index != RXRPC_SECURITY_RXKAD)
+		goto error;
+
+	plen = sizeof(*token->kad) + v1->ticket_length;
+	prep->quotalen = plen + sizeof(*token);
+
+	ret = -ENOMEM;
+	token = kzalloc(sizeof(*token), GFP_KERNEL);
+	if (!token)
+		goto error;
+	token->kad = kzalloc(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);
+
+	/* count the number of tokens attached */
+	prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
+
+	/* attach the data */
+	pp = (struct rxrpc_key_token **)&prep->payload.data[0];
+	while (*pp)
+		pp = &(*pp)->next;
+	*pp = token;
+	expiry = rxrpc_u32_to_time64(token->kad->expiry);
+	if (expiry < prep->expiry)
+		prep->expiry = expiry;
+	token = NULL;
+	ret = 0;
+
+error_free:
+	kfree(token);
+error:
+	return ret;
+}
+
+/*
+ * Free token list.
+ */
+static void rxrpc_free_token_list(struct rxrpc_key_token *token)
+{
+	struct rxrpc_key_token *next;
+
+	for (; token; token = next) {
+		next = token->next;
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			kfree(token->kad);
+			break;
+		case RXRPC_SECURITY_RXK5:
+			if (token->k5)
+				rxrpc_rxk5_free(token->k5);
+			break;
+		default:
+			pr_err("Unknown token type %x on rxrpc key\n",
+			       token->security_index);
+			BUG();
+		}
+
+		kfree(token);
+	}
+}
+
+/*
+ * Clean up preparse data.
+ */
+static void rxrpc_free_preparse(struct key_preparsed_payload *prep)
+{
+	rxrpc_free_token_list(prep->payload.data[0]);
+}
+
+/*
+ * Preparse a server secret key.
+ *
+ * The data should be the 8-byte secret key.
+ */
+static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
+{
+	struct crypto_skcipher *ci;
+
+	_enter("%zu", prep->datalen);
+
+	if (prep->datalen != 8)
+		return -EINVAL;
+
+	memcpy(&prep->payload.data[2], prep->data, 8);
+
+	ci = crypto_alloc_skcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(ci)) {
+		_leave(" = %ld", PTR_ERR(ci));
+		return PTR_ERR(ci);
+	}
+
+	if (crypto_skcipher_setkey(ci, prep->data, 8) < 0)
+		BUG();
+
+	prep->payload.data[0] = ci;
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * Clean up preparse data.
+ */
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
+{
+	if (prep->payload.data[0])
+		crypto_free_skcipher(prep->payload.data[0]);
+}
+
+/*
+ * dispose of the data dangling from the corpse of a rxrpc key
+ */
+static void rxrpc_destroy(struct key *key)
+{
+	rxrpc_free_token_list(key->payload.data[0]);
+}
+
+/*
+ * dispose of the data dangling from the corpse of a rxrpc key
+ */
+static void rxrpc_destroy_s(struct key *key)
+{
+	if (key->payload.data[0]) {
+		crypto_free_skcipher(key->payload.data[0]);
+		key->payload.data[0] = NULL;
+	}
+}
+
+/*
+ * describe the rxrpc key
+ */
+static void rxrpc_describe(const struct key *key, struct seq_file *m)
+{
+	seq_puts(m, key->description);
+}
+
+/*
+ * grab the security key for a socket
+ */
+int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
+{
+	struct key *key;
+	char *description;
+
+	_enter("");
+
+	if (optlen <= 0 || optlen > PAGE_SIZE - 1 || rx->securities)
+		return -EINVAL;
+
+	description = memdup_user_nul(optval, optlen);
+	if (IS_ERR(description))
+		return PTR_ERR(description);
+
+	key = request_key(&key_type_rxrpc, description, NULL);
+	if (IS_ERR(key)) {
+		kfree(description);
+		_leave(" = %ld", PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+
+	rx->key = key;
+	kfree(description);
+	_leave(" = 0 [key %x]", key->serial);
+	return 0;
+}
+
+/*
+ * grab the security keyring for a server socket
+ */
+int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
+			 int optlen)
+{
+	struct key *key;
+	char *description;
+
+	_enter("");
+
+	if (optlen <= 0 || optlen > PAGE_SIZE - 1)
+		return -EINVAL;
+
+	description = memdup_user_nul(optval, optlen);
+	if (IS_ERR(description))
+		return PTR_ERR(description);
+
+	key = request_key(&key_type_keyring, description, NULL);
+	if (IS_ERR(key)) {
+		kfree(description);
+		_leave(" = %ld", PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+
+	rx->securities = key;
+	kfree(description);
+	_leave(" = 0 [key %x]", key->serial);
+	return 0;
+}
+
+/*
+ * generate a server data key
+ */
+int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
+			      const void *session_key,
+			      time64_t expiry,
+			      u32 kvno)
+{
+	const struct cred *cred = current_cred();
+	struct key *key;
+	int ret;
+
+	struct {
+		u32 kver;
+		struct rxrpc_key_data_v1 v1;
+	} data;
+
+	_enter("");
+
+	key = key_alloc(&key_type_rxrpc, "x",
+			GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0,
+			KEY_ALLOC_NOT_IN_QUOTA, NULL);
+	if (IS_ERR(key)) {
+		_leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
+		return -ENOMEM;
+	}
+
+	_debug("key %d", key_serial(key));
+
+	data.kver = 1;
+	data.v1.security_index = RXRPC_SECURITY_RXKAD;
+	data.v1.ticket_length = 0;
+	data.v1.expiry = rxrpc_time64_to_u32(expiry);
+	data.v1.kvno = 0;
+
+	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)
+		goto error;
+
+	conn->params.key = key;
+	_leave(" = 0 [%d]", key_serial(key));
+	return 0;
+
+error:
+	key_revoke(key);
+	key_put(key);
+	_leave(" = -ENOMEM [ins %d]", ret);
+	return -ENOMEM;
+}
+EXPORT_SYMBOL(rxrpc_get_server_data_key);
+
+/**
+ * rxrpc_get_null_key - Generate a null RxRPC key
+ * @keyname: The name to give the key.
+ *
+ * Generate a null RxRPC key that can be used to indicate anonymous security is
+ * required for a particular domain.
+ */
+struct key *rxrpc_get_null_key(const char *keyname)
+{
+	const struct cred *cred = current_cred();
+	struct key *key;
+	int ret;
+
+	key = key_alloc(&key_type_rxrpc, keyname,
+			GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
+			KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, NULL);
+	if (IS_ERR(key))
+		return key;
+
+	ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
+	if (ret < 0) {
+		key_revoke(key);
+		key_put(key);
+		return ERR_PTR(ret);
+	}
+
+	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 *buffer, size_t buflen)
+{
+	const struct rxrpc_key_token *token;
+	const struct krb5_principal *princ;
+	size_t size;
+	__be32 *xdr, *oldxdr;
+	u32 cnlen, toksize, ntoks, tok, zero;
+	u16 toksizes[AFSTOKEN_MAX];
+	int loop;
+
+	_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);
+
+#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 += RND(cnlen);	/* cellname */
+	size += 1 * 4;	/* token count */
+
+	ntoks = 0;
+	for (token = key->payload.data[0]; token; token = token->next) {
+		toksize = 4;	/* sec index */
+
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			toksize += 8 * 4;	/* viceid, kvno, key*2, begin,
+						 * end, primary, tktlen */
+			toksize += RND(token->kad->ticket_len);
+			break;
+
+		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 */
+			pr_err("Unsupported key token type (%u)\n",
+			       token->security_index);
+			return -ENOPKG;
+		}
+
+		_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;
+
+	xdr = (__be32 *)buffer;
+	zero = 0;
+#define ENCODE(x)				\
+	do {					\
+		*xdr++ = htonl(x);		\
+	} while(0)
+#define ENCODE_DATA(l, s)						\
+	do {								\
+		u32 _l = (l);						\
+		ENCODE(l);						\
+		memcpy(xdr, (s), _l);					\
+		if (_l & 3)						\
+			memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3));	\
+		xdr += (_l + 3) >> 2;					\
+	} while(0)
+#define ENCODE_BYTES(l, s)						\
+	do {								\
+		u32 _l = (l);						\
+		memcpy(xdr, (s), _l);					\
+		if (_l & 3)						\
+			memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3));	\
+		xdr += (_l + 3) >> 2;					\
+	} while(0)
+#define ENCODE64(x)					\
+	do {						\
+		__be64 y = cpu_to_be64(x);		\
+		memcpy(xdr, &y, 8);			\
+		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_DATA(cnlen, key->description + 4);	/* cellname */
+	ENCODE(ntoks);
+
+	tok = 0;
+	for (token = key->payload.data[0]; token; token = token->next) {
+		toksize = toksizes[tok++];
+		ENCODE(toksize);
+		oldxdr = xdr;
+		ENCODE(token->security_index);
+
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			ENCODE(token->kad->vice_id);
+			ENCODE(token->kad->kvno);
+			ENCODE_BYTES(8, token->kad->session_key);
+			ENCODE(token->kad->start);
+			ENCODE(token->kad->expiry);
+			ENCODE(token->kad->primary_flag);
+			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:
+			pr_err("Unsupported key token type (%u)\n",
+			       token->security_index);
+			return -ENOPKG;
+		}
+
+		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;
+}