Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / rxrpc / ar-key.c
diff --git a/kernel/net/rxrpc/ar-key.c b/kernel/net/rxrpc/ar-key.c
new file mode 100644 (file)
index 0000000..db0f39f
--- /dev/null
@@ -0,0 +1,1247 @@
+/* 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>
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/key-type.h>
+#include <linux/crypto.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 __user *, 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;
+       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->type_data[0] = (void *)((unsigned long)prep->type_data[0] + 1);
+
+       /* attach the data */
+       for (pptoken = (struct rxrpc_key_token **)&prep->payload[0];
+            *pptoken;
+            pptoken = &(*pptoken)->next)
+               continue;
+       *pptoken = token;
+       if (token->kad->expiry < prep->expiry)
+               prep->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 int *_toklen)
+{
+       const __be32 *xdr = *_xdr;
+       unsigned int 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(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;
+               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 int *_toklen)
+{
+       const __be32 *xdr = *_xdr;
+       unsigned int 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 = kmemdup(xdr, len, GFP_KERNEL);
+               if (!td->data)
+                       return -ENOMEM;
+               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 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;
+
+       /* 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 = kmemdup(xdr, len, GFP_KERNEL);
+               if (!*_ticket)
+                       return -ENOMEM;
+               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_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);
+       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[0];
+            *pptoken;
+            pptoken = &(*pptoken)->next)
+               continue;
+       *pptoken = token;
+       if (token->kad->expiry < prep->expiry)
+               prep->expiry = token->kad->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, tmp, 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;
+       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;
+
+               _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;
+       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->type_data[0] = (void *)((unsigned long)prep->type_data[0] + 1);
+
+       /* attach the data */
+       pp = (struct rxrpc_key_token **)&prep->payload[0];
+       while (*pp)
+               pp = &(*pp)->next;
+       *pp = token;
+       if (token->kad->expiry < prep->expiry)
+               prep->expiry = token->kad->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:
+                       printk(KERN_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[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_blkcipher *ci;
+
+       _enter("%zu", prep->datalen);
+
+       if (prep->datalen != 8)
+               return -EINVAL;
+
+       memcpy(&prep->type_data, prep->data, 8);
+
+       ci = crypto_alloc_blkcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
+       if (IS_ERR(ci)) {
+               _leave(" = %ld", PTR_ERR(ci));
+               return PTR_ERR(ci);
+       }
+
+       if (crypto_blkcipher_setkey(ci, prep->data, 8) < 0)
+               BUG();
+
+       prep->payload[0] = ci;
+       _leave(" = 0");
+       return 0;
+}
+
+/*
+ * Clean up preparse data.
+ */
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
+{
+       if (prep->payload[0])
+               crypto_free_blkcipher(prep->payload[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);
+}
+
+/*
+ * dispose of the data dangling from the corpse of a rxrpc key
+ */
+static void rxrpc_destroy_s(struct key *key)
+{
+       if (key->payload.data) {
+               crypto_free_blkcipher(key->payload.data);
+               key->payload.data = 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)
+               return -EINVAL;
+
+       description = kmalloc(optlen + 1, GFP_KERNEL);
+       if (!description)
+               return -ENOMEM;
+
+       if (copy_from_user(description, optval, optlen)) {
+               kfree(description);
+               return -EFAULT;
+       }
+       description[optlen] = 0;
+
+       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 = kmalloc(optlen + 1, GFP_KERNEL);
+       if (!description)
+               return -ENOMEM;
+
+       if (copy_from_user(description, optval, optlen)) {
+               kfree(description);
+               return -EFAULT;
+       }
+       description[optlen] = 0;
+
+       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,
+                             time_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);
+       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 = 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->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);
+       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 __user *buffer, size_t buflen)
+{
+       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("");
+
+       /* 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; 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 */
+                       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;
+
+       xdr = (__be32 __user *) buffer;
+       zero = 0;
+#define ENCODE(x)                              \
+       do {                                    \
+               __be32 y = htonl(x);            \
+               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 __user *)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_DATA(cnlen, key->description + 4);       /* cellname */
+       ENCODE(ntoks);
+
+       tok = 0;
+       for (token = key->payload.data; 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_DATA(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:
+                       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;
+
+fault:
+       _leave(" = -EFAULT");
+       return -EFAULT;
+}