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TOMOYO Linux Cross Reference
Linux/net/rxrpc/key.c

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  1 /* RxRPC key management
  2  *
  3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
  4  * Written by David Howells (dhowells@redhat.com)
  5  *
  6  * This program is free software; you can redistribute it and/or
  7  * modify it under the terms of the GNU General Public License
  8  * as published by the Free Software Foundation; either version
  9  * 2 of the License, or (at your option) any later version.
 10  *
 11  * RxRPC keys should have a description of describing their purpose:
 12  *      "afs@CAMBRIDGE.REDHAT.COM>
 13  */
 14 
 15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 16 
 17 #include <crypto/skcipher.h>
 18 #include <linux/module.h>
 19 #include <linux/net.h>
 20 #include <linux/skbuff.h>
 21 #include <linux/key-type.h>
 22 #include <linux/ctype.h>
 23 #include <linux/slab.h>
 24 #include <net/sock.h>
 25 #include <net/af_rxrpc.h>
 26 #include <keys/rxrpc-type.h>
 27 #include <keys/user-type.h>
 28 #include "ar-internal.h"
 29 
 30 static int rxrpc_vet_description_s(const char *);
 31 static int rxrpc_preparse(struct key_preparsed_payload *);
 32 static int rxrpc_preparse_s(struct key_preparsed_payload *);
 33 static void rxrpc_free_preparse(struct key_preparsed_payload *);
 34 static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
 35 static void rxrpc_destroy(struct key *);
 36 static void rxrpc_destroy_s(struct key *);
 37 static void rxrpc_describe(const struct key *, struct seq_file *);
 38 static long rxrpc_read(const struct key *, char __user *, size_t);
 39 
 40 /*
 41  * rxrpc defined keys take an arbitrary string as the description and an
 42  * arbitrary blob of data as the payload
 43  */
 44 struct key_type key_type_rxrpc = {
 45         .name           = "rxrpc",
 46         .preparse       = rxrpc_preparse,
 47         .free_preparse  = rxrpc_free_preparse,
 48         .instantiate    = generic_key_instantiate,
 49         .destroy        = rxrpc_destroy,
 50         .describe       = rxrpc_describe,
 51         .read           = rxrpc_read,
 52 };
 53 EXPORT_SYMBOL(key_type_rxrpc);
 54 
 55 /*
 56  * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
 57  * description and an 8-byte decryption key as the payload
 58  */
 59 struct key_type key_type_rxrpc_s = {
 60         .name           = "rxrpc_s",
 61         .vet_description = rxrpc_vet_description_s,
 62         .preparse       = rxrpc_preparse_s,
 63         .free_preparse  = rxrpc_free_preparse_s,
 64         .instantiate    = generic_key_instantiate,
 65         .destroy        = rxrpc_destroy_s,
 66         .describe       = rxrpc_describe,
 67 };
 68 
 69 /*
 70  * Vet the description for an RxRPC server key
 71  */
 72 static int rxrpc_vet_description_s(const char *desc)
 73 {
 74         unsigned long num;
 75         char *p;
 76 
 77         num = simple_strtoul(desc, &p, 10);
 78         if (*p != ':' || num > 65535)
 79                 return -EINVAL;
 80         num = simple_strtoul(p + 1, &p, 10);
 81         if (*p || num < 1 || num > 255)
 82                 return -EINVAL;
 83         return 0;
 84 }
 85 
 86 /*
 87  * parse an RxKAD type XDR format token
 88  * - the caller guarantees we have at least 4 words
 89  */
 90 static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep,
 91                                     size_t datalen,
 92                                     const __be32 *xdr, unsigned int toklen)
 93 {
 94         struct rxrpc_key_token *token, **pptoken;
 95         size_t plen;
 96         u32 tktlen;
 97 
 98         _enter(",{%x,%x,%x,%x},%u",
 99                ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
100                toklen);
101 
102         if (toklen <= 8 * 4)
103                 return -EKEYREJECTED;
104         tktlen = ntohl(xdr[7]);
105         _debug("tktlen: %x", tktlen);
106         if (tktlen > AFSTOKEN_RK_TIX_MAX)
107                 return -EKEYREJECTED;
108         if (toklen < 8 * 4 + tktlen)
109                 return -EKEYREJECTED;
110 
111         plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
112         prep->quotalen = datalen + plen;
113 
114         plen -= sizeof(*token);
115         token = kzalloc(sizeof(*token), GFP_KERNEL);
116         if (!token)
117                 return -ENOMEM;
118 
119         token->kad = kzalloc(plen, GFP_KERNEL);
120         if (!token->kad) {
121                 kfree(token);
122                 return -ENOMEM;
123         }
124 
125         token->security_index   = RXRPC_SECURITY_RXKAD;
126         token->kad->ticket_len  = tktlen;
127         token->kad->vice_id     = ntohl(xdr[0]);
128         token->kad->kvno        = ntohl(xdr[1]);
129         token->kad->start       = ntohl(xdr[4]);
130         token->kad->expiry      = ntohl(xdr[5]);
131         token->kad->primary_flag = ntohl(xdr[6]);
132         memcpy(&token->kad->session_key, &xdr[2], 8);
133         memcpy(&token->kad->ticket, &xdr[8], tktlen);
134 
135         _debug("SCIX: %u", token->security_index);
136         _debug("TLEN: %u", token->kad->ticket_len);
137         _debug("EXPY: %x", token->kad->expiry);
138         _debug("KVNO: %u", token->kad->kvno);
139         _debug("PRIM: %u", token->kad->primary_flag);
140         _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
141                token->kad->session_key[0], token->kad->session_key[1],
142                token->kad->session_key[2], token->kad->session_key[3],
143                token->kad->session_key[4], token->kad->session_key[5],
144                token->kad->session_key[6], token->kad->session_key[7]);
145         if (token->kad->ticket_len >= 8)
146                 _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
147                        token->kad->ticket[0], token->kad->ticket[1],
148                        token->kad->ticket[2], token->kad->ticket[3],
149                        token->kad->ticket[4], token->kad->ticket[5],
150                        token->kad->ticket[6], token->kad->ticket[7]);
151 
152         /* count the number of tokens attached */
153         prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
154 
155         /* attach the data */
156         for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
157              *pptoken;
158              pptoken = &(*pptoken)->next)
159                 continue;
160         *pptoken = token;
161         if (token->kad->expiry < prep->expiry)
162                 prep->expiry = token->kad->expiry;
163 
164         _leave(" = 0");
165         return 0;
166 }
167 
168 static void rxrpc_free_krb5_principal(struct krb5_principal *princ)
169 {
170         int loop;
171 
172         if (princ->name_parts) {
173                 for (loop = princ->n_name_parts - 1; loop >= 0; loop--)
174                         kfree(princ->name_parts[loop]);
175                 kfree(princ->name_parts);
176         }
177         kfree(princ->realm);
178 }
179 
180 static void rxrpc_free_krb5_tagged(struct krb5_tagged_data *td)
181 {
182         kfree(td->data);
183 }
184 
185 /*
186  * free up an RxK5 token
187  */
188 static void rxrpc_rxk5_free(struct rxk5_key *rxk5)
189 {
190         int loop;
191 
192         rxrpc_free_krb5_principal(&rxk5->client);
193         rxrpc_free_krb5_principal(&rxk5->server);
194         rxrpc_free_krb5_tagged(&rxk5->session);
195 
196         if (rxk5->addresses) {
197                 for (loop = rxk5->n_addresses - 1; loop >= 0; loop--)
198                         rxrpc_free_krb5_tagged(&rxk5->addresses[loop]);
199                 kfree(rxk5->addresses);
200         }
201         if (rxk5->authdata) {
202                 for (loop = rxk5->n_authdata - 1; loop >= 0; loop--)
203                         rxrpc_free_krb5_tagged(&rxk5->authdata[loop]);
204                 kfree(rxk5->authdata);
205         }
206 
207         kfree(rxk5->ticket);
208         kfree(rxk5->ticket2);
209         kfree(rxk5);
210 }
211 
212 /*
213  * extract a krb5 principal
214  */
215 static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
216                                        const __be32 **_xdr,
217                                        unsigned int *_toklen)
218 {
219         const __be32 *xdr = *_xdr;
220         unsigned int toklen = *_toklen, n_parts, loop, tmp;
221 
222         /* there must be at least one name, and at least #names+1 length
223          * words */
224         if (toklen <= 12)
225                 return -EINVAL;
226 
227         _enter(",{%x,%x,%x},%u",
228                ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), toklen);
229 
230         n_parts = ntohl(*xdr++);
231         toklen -= 4;
232         if (n_parts <= 0 || n_parts > AFSTOKEN_K5_COMPONENTS_MAX)
233                 return -EINVAL;
234         princ->n_name_parts = n_parts;
235 
236         if (toklen <= (n_parts + 1) * 4)
237                 return -EINVAL;
238 
239         princ->name_parts = kcalloc(n_parts, sizeof(char *), GFP_KERNEL);
240         if (!princ->name_parts)
241                 return -ENOMEM;
242 
243         for (loop = 0; loop < n_parts; loop++) {
244                 if (toklen < 4)
245                         return -EINVAL;
246                 tmp = ntohl(*xdr++);
247                 toklen -= 4;
248                 if (tmp <= 0 || tmp > AFSTOKEN_STRING_MAX)
249                         return -EINVAL;
250                 if (tmp > toklen)
251                         return -EINVAL;
252                 princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
253                 if (!princ->name_parts[loop])
254                         return -ENOMEM;
255                 memcpy(princ->name_parts[loop], xdr, tmp);
256                 princ->name_parts[loop][tmp] = 0;
257                 tmp = (tmp + 3) & ~3;
258                 toklen -= tmp;
259                 xdr += tmp >> 2;
260         }
261 
262         if (toklen < 4)
263                 return -EINVAL;
264         tmp = ntohl(*xdr++);
265         toklen -= 4;
266         if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
267                 return -EINVAL;
268         if (tmp > toklen)
269                 return -EINVAL;
270         princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
271         if (!princ->realm)
272                 return -ENOMEM;
273         memcpy(princ->realm, xdr, tmp);
274         princ->realm[tmp] = 0;
275         tmp = (tmp + 3) & ~3;
276         toklen -= tmp;
277         xdr += tmp >> 2;
278 
279         _debug("%s/...@%s", princ->name_parts[0], princ->realm);
280 
281         *_xdr = xdr;
282         *_toklen = toklen;
283         _leave(" = 0 [toklen=%u]", toklen);
284         return 0;
285 }
286 
287 /*
288  * extract a piece of krb5 tagged data
289  */
290 static int rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data *td,
291                                          size_t max_data_size,
292                                          const __be32 **_xdr,
293                                          unsigned int *_toklen)
294 {
295         const __be32 *xdr = *_xdr;
296         unsigned int toklen = *_toklen, len;
297 
298         /* there must be at least one tag and one length word */
299         if (toklen <= 8)
300                 return -EINVAL;
301 
302         _enter(",%zu,{%x,%x},%u",
303                max_data_size, ntohl(xdr[0]), ntohl(xdr[1]), toklen);
304 
305         td->tag = ntohl(*xdr++);
306         len = ntohl(*xdr++);
307         toklen -= 8;
308         if (len > max_data_size)
309                 return -EINVAL;
310         td->data_len = len;
311 
312         if (len > 0) {
313                 td->data = kmemdup(xdr, len, GFP_KERNEL);
314                 if (!td->data)
315                         return -ENOMEM;
316                 len = (len + 3) & ~3;
317                 toklen -= len;
318                 xdr += len >> 2;
319         }
320 
321         _debug("tag %x len %x", td->tag, td->data_len);
322 
323         *_xdr = xdr;
324         *_toklen = toklen;
325         _leave(" = 0 [toklen=%u]", toklen);
326         return 0;
327 }
328 
329 /*
330  * extract an array of tagged data
331  */
332 static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
333                                           u8 *_n_elem,
334                                           u8 max_n_elem,
335                                           size_t max_elem_size,
336                                           const __be32 **_xdr,
337                                           unsigned int *_toklen)
338 {
339         struct krb5_tagged_data *td;
340         const __be32 *xdr = *_xdr;
341         unsigned int toklen = *_toklen, n_elem, loop;
342         int ret;
343 
344         /* there must be at least one count */
345         if (toklen < 4)
346                 return -EINVAL;
347 
348         _enter(",,%u,%zu,{%x},%u",
349                max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
350 
351         n_elem = ntohl(*xdr++);
352         toklen -= 4;
353         if (n_elem > max_n_elem)
354                 return -EINVAL;
355         *_n_elem = n_elem;
356         if (n_elem > 0) {
357                 if (toklen <= (n_elem + 1) * 4)
358                         return -EINVAL;
359 
360                 _debug("n_elem %d", n_elem);
361 
362                 td = kcalloc(n_elem, sizeof(struct krb5_tagged_data),
363                              GFP_KERNEL);
364                 if (!td)
365                         return -ENOMEM;
366                 *_td = td;
367 
368                 for (loop = 0; loop < n_elem; loop++) {
369                         ret = rxrpc_krb5_decode_tagged_data(&td[loop],
370                                                             max_elem_size,
371                                                             &xdr, &toklen);
372                         if (ret < 0)
373                                 return ret;
374                 }
375         }
376 
377         *_xdr = xdr;
378         *_toklen = toklen;
379         _leave(" = 0 [toklen=%u]", toklen);
380         return 0;
381 }
382 
383 /*
384  * extract a krb5 ticket
385  */
386 static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
387                                     const __be32 **_xdr, unsigned int *_toklen)
388 {
389         const __be32 *xdr = *_xdr;
390         unsigned int toklen = *_toklen, len;
391 
392         /* there must be at least one length word */
393         if (toklen <= 4)
394                 return -EINVAL;
395 
396         _enter(",{%x},%u", ntohl(xdr[0]), toklen);
397 
398         len = ntohl(*xdr++);
399         toklen -= 4;
400         if (len > AFSTOKEN_K5_TIX_MAX)
401                 return -EINVAL;
402         *_tktlen = len;
403 
404         _debug("ticket len %u", len);
405 
406         if (len > 0) {
407                 *_ticket = kmemdup(xdr, len, GFP_KERNEL);
408                 if (!*_ticket)
409                         return -ENOMEM;
410                 len = (len + 3) & ~3;
411                 toklen -= len;
412                 xdr += len >> 2;
413         }
414 
415         *_xdr = xdr;
416         *_toklen = toklen;
417         _leave(" = 0 [toklen=%u]", toklen);
418         return 0;
419 }
420 
421 /*
422  * parse an RxK5 type XDR format token
423  * - the caller guarantees we have at least 4 words
424  */
425 static int rxrpc_preparse_xdr_rxk5(struct key_preparsed_payload *prep,
426                                    size_t datalen,
427                                    const __be32 *xdr, unsigned int toklen)
428 {
429         struct rxrpc_key_token *token, **pptoken;
430         struct rxk5_key *rxk5;
431         const __be32 *end_xdr = xdr + (toklen >> 2);
432         int ret;
433 
434         _enter(",{%x,%x,%x,%x},%u",
435                ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
436                toklen);
437 
438         /* reserve some payload space for this subkey - the length of the token
439          * is a reasonable approximation */
440         prep->quotalen = datalen + toklen;
441 
442         token = kzalloc(sizeof(*token), GFP_KERNEL);
443         if (!token)
444                 return -ENOMEM;
445 
446         rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
447         if (!rxk5) {
448                 kfree(token);
449                 return -ENOMEM;
450         }
451 
452         token->security_index = RXRPC_SECURITY_RXK5;
453         token->k5 = rxk5;
454 
455         /* extract the principals */
456         ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
457         if (ret < 0)
458                 goto error;
459         ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
460         if (ret < 0)
461                 goto error;
462 
463         /* extract the session key and the encoding type (the tag field ->
464          * ENCTYPE_xxx) */
465         ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
466                                             &xdr, &toklen);
467         if (ret < 0)
468                 goto error;
469 
470         if (toklen < 4 * 8 + 2 * 4)
471                 goto inval;
472         rxk5->authtime  = be64_to_cpup((const __be64 *) xdr);
473         xdr += 2;
474         rxk5->starttime = be64_to_cpup((const __be64 *) xdr);
475         xdr += 2;
476         rxk5->endtime   = be64_to_cpup((const __be64 *) xdr);
477         xdr += 2;
478         rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
479         xdr += 2;
480         rxk5->is_skey = ntohl(*xdr++);
481         rxk5->flags = ntohl(*xdr++);
482         toklen -= 4 * 8 + 2 * 4;
483 
484         _debug("times: a=%llx s=%llx e=%llx rt=%llx",
485                rxk5->authtime, rxk5->starttime, rxk5->endtime,
486                rxk5->renew_till);
487         _debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
488 
489         /* extract the permitted client addresses */
490         ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
491                                              &rxk5->n_addresses,
492                                              AFSTOKEN_K5_ADDRESSES_MAX,
493                                              AFSTOKEN_DATA_MAX,
494                                              &xdr, &toklen);
495         if (ret < 0)
496                 goto error;
497 
498         ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
499 
500         /* extract the tickets */
501         ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
502                                        &xdr, &toklen);
503         if (ret < 0)
504                 goto error;
505         ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
506                                        &xdr, &toklen);
507         if (ret < 0)
508                 goto error;
509 
510         ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
511 
512         /* extract the typed auth data */
513         ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
514                                              &rxk5->n_authdata,
515                                              AFSTOKEN_K5_AUTHDATA_MAX,
516                                              AFSTOKEN_BDATALN_MAX,
517                                              &xdr, &toklen);
518         if (ret < 0)
519                 goto error;
520 
521         ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
522 
523         if (toklen != 0)
524                 goto inval;
525 
526         /* attach the payload */
527         for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
528              *pptoken;
529              pptoken = &(*pptoken)->next)
530                 continue;
531         *pptoken = token;
532         if (token->kad->expiry < prep->expiry)
533                 prep->expiry = token->kad->expiry;
534 
535         _leave(" = 0");
536         return 0;
537 
538 inval:
539         ret = -EINVAL;
540 error:
541         rxrpc_rxk5_free(rxk5);
542         kfree(token);
543         _leave(" = %d", ret);
544         return ret;
545 }
546 
547 /*
548  * attempt to parse the data as the XDR format
549  * - the caller guarantees we have more than 7 words
550  */
551 static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)
552 {
553         const __be32 *xdr = prep->data, *token;
554         const char *cp;
555         unsigned int len, tmp, loop, ntoken, toklen, sec_ix;
556         size_t datalen = prep->datalen;
557         int ret;
558 
559         _enter(",{%x,%x,%x,%x},%zu",
560                ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
561                prep->datalen);
562 
563         if (datalen > AFSTOKEN_LENGTH_MAX)
564                 goto not_xdr;
565 
566         /* XDR is an array of __be32's */
567         if (datalen & 3)
568                 goto not_xdr;
569 
570         /* the flags should be 0 (the setpag bit must be handled by
571          * userspace) */
572         if (ntohl(*xdr++) != 0)
573                 goto not_xdr;
574         datalen -= 4;
575 
576         /* check the cell name */
577         len = ntohl(*xdr++);
578         if (len < 1 || len > AFSTOKEN_CELL_MAX)
579                 goto not_xdr;
580         datalen -= 4;
581         tmp = (len + 3) & ~3;
582         if (tmp > datalen)
583                 goto not_xdr;
584 
585         cp = (const char *) xdr;
586         for (loop = 0; loop < len; loop++)
587                 if (!isprint(cp[loop]))
588                         goto not_xdr;
589         if (len < tmp)
590                 for (; loop < tmp; loop++)
591                         if (cp[loop])
592                                 goto not_xdr;
593         _debug("cellname: [%u/%u] '%*.*s'",
594                len, tmp, len, len, (const char *) xdr);
595         datalen -= tmp;
596         xdr += tmp >> 2;
597 
598         /* get the token count */
599         if (datalen < 12)
600                 goto not_xdr;
601         ntoken = ntohl(*xdr++);
602         datalen -= 4;
603         _debug("ntoken: %x", ntoken);
604         if (ntoken < 1 || ntoken > AFSTOKEN_MAX)
605                 goto not_xdr;
606 
607         /* check each token wrapper */
608         token = xdr;
609         loop = ntoken;
610         do {
611                 if (datalen < 8)
612                         goto not_xdr;
613                 toklen = ntohl(*xdr++);
614                 sec_ix = ntohl(*xdr);
615                 datalen -= 4;
616                 _debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);
617                 if (toklen < 20 || toklen > datalen)
618                         goto not_xdr;
619                 datalen -= (toklen + 3) & ~3;
620                 xdr += (toklen + 3) >> 2;
621 
622         } while (--loop > 0);
623 
624         _debug("remainder: %zu", datalen);
625         if (datalen != 0)
626                 goto not_xdr;
627 
628         /* okay: we're going to assume it's valid XDR format
629          * - we ignore the cellname, relying on the key to be correctly named
630          */
631         do {
632                 xdr = token;
633                 toklen = ntohl(*xdr++);
634                 token = xdr + ((toklen + 3) >> 2);
635                 sec_ix = ntohl(*xdr++);
636                 toklen -= 4;
637 
638                 _debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
639 
640                 switch (sec_ix) {
641                 case RXRPC_SECURITY_RXKAD:
642                         ret = rxrpc_preparse_xdr_rxkad(prep, datalen, xdr, toklen);
643                         if (ret != 0)
644                                 goto error;
645                         break;
646 
647                 case RXRPC_SECURITY_RXK5:
648                         ret = rxrpc_preparse_xdr_rxk5(prep, datalen, xdr, toklen);
649                         if (ret != 0)
650                                 goto error;
651                         break;
652 
653                 default:
654                         ret = -EPROTONOSUPPORT;
655                         goto error;
656                 }
657 
658         } while (--ntoken > 0);
659 
660         _leave(" = 0");
661         return 0;
662 
663 not_xdr:
664         _leave(" = -EPROTO");
665         return -EPROTO;
666 error:
667         _leave(" = %d", ret);
668         return ret;
669 }
670 
671 /*
672  * Preparse an rxrpc defined key.
673  *
674  * Data should be of the form:
675  *      OFFSET  LEN     CONTENT
676  *      0       4       key interface version number
677  *      4       2       security index (type)
678  *      6       2       ticket length
679  *      8       4       key expiry time (time_t)
680  *      12      4       kvno
681  *      16      8       session key
682  *      24      [len]   ticket
683  *
684  * if no data is provided, then a no-security key is made
685  */
686 static int rxrpc_preparse(struct key_preparsed_payload *prep)
687 {
688         const struct rxrpc_key_data_v1 *v1;
689         struct rxrpc_key_token *token, **pp;
690         size_t plen;
691         u32 kver;
692         int ret;
693 
694         _enter("%zu", prep->datalen);
695 
696         /* handle a no-security key */
697         if (!prep->data && prep->datalen == 0)
698                 return 0;
699 
700         /* determine if the XDR payload format is being used */
701         if (prep->datalen > 7 * 4) {
702                 ret = rxrpc_preparse_xdr(prep);
703                 if (ret != -EPROTO)
704                         return ret;
705         }
706 
707         /* get the key interface version number */
708         ret = -EINVAL;
709         if (prep->datalen <= 4 || !prep->data)
710                 goto error;
711         memcpy(&kver, prep->data, sizeof(kver));
712         prep->data += sizeof(kver);
713         prep->datalen -= sizeof(kver);
714 
715         _debug("KEY I/F VERSION: %u", kver);
716 
717         ret = -EKEYREJECTED;
718         if (kver != 1)
719                 goto error;
720 
721         /* deal with a version 1 key */
722         ret = -EINVAL;
723         if (prep->datalen < sizeof(*v1))
724                 goto error;
725 
726         v1 = prep->data;
727         if (prep->datalen != sizeof(*v1) + v1->ticket_length)
728                 goto error;
729 
730         _debug("SCIX: %u", v1->security_index);
731         _debug("TLEN: %u", v1->ticket_length);
732         _debug("EXPY: %x", v1->expiry);
733         _debug("KVNO: %u", v1->kvno);
734         _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
735                v1->session_key[0], v1->session_key[1],
736                v1->session_key[2], v1->session_key[3],
737                v1->session_key[4], v1->session_key[5],
738                v1->session_key[6], v1->session_key[7]);
739         if (v1->ticket_length >= 8)
740                 _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
741                        v1->ticket[0], v1->ticket[1],
742                        v1->ticket[2], v1->ticket[3],
743                        v1->ticket[4], v1->ticket[5],
744                        v1->ticket[6], v1->ticket[7]);
745 
746         ret = -EPROTONOSUPPORT;
747         if (v1->security_index != RXRPC_SECURITY_RXKAD)
748                 goto error;
749 
750         plen = sizeof(*token->kad) + v1->ticket_length;
751         prep->quotalen = plen + sizeof(*token);
752 
753         ret = -ENOMEM;
754         token = kzalloc(sizeof(*token), GFP_KERNEL);
755         if (!token)
756                 goto error;
757         token->kad = kzalloc(plen, GFP_KERNEL);
758         if (!token->kad)
759                 goto error_free;
760 
761         token->security_index           = RXRPC_SECURITY_RXKAD;
762         token->kad->ticket_len          = v1->ticket_length;
763         token->kad->expiry              = v1->expiry;
764         token->kad->kvno                = v1->kvno;
765         memcpy(&token->kad->session_key, &v1->session_key, 8);
766         memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
767 
768         /* count the number of tokens attached */
769         prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
770 
771         /* attach the data */
772         pp = (struct rxrpc_key_token **)&prep->payload.data[0];
773         while (*pp)
774                 pp = &(*pp)->next;
775         *pp = token;
776         if (token->kad->expiry < prep->expiry)
777                 prep->expiry = token->kad->expiry;
778         token = NULL;
779         ret = 0;
780 
781 error_free:
782         kfree(token);
783 error:
784         return ret;
785 }
786 
787 /*
788  * Free token list.
789  */
790 static void rxrpc_free_token_list(struct rxrpc_key_token *token)
791 {
792         struct rxrpc_key_token *next;
793 
794         for (; token; token = next) {
795                 next = token->next;
796                 switch (token->security_index) {
797                 case RXRPC_SECURITY_RXKAD:
798                         kfree(token->kad);
799                         break;
800                 case RXRPC_SECURITY_RXK5:
801                         if (token->k5)
802                                 rxrpc_rxk5_free(token->k5);
803                         break;
804                 default:
805                         pr_err("Unknown token type %x on rxrpc key\n",
806                                token->security_index);
807                         BUG();
808                 }
809 
810                 kfree(token);
811         }
812 }
813 
814 /*
815  * Clean up preparse data.
816  */
817 static void rxrpc_free_preparse(struct key_preparsed_payload *prep)
818 {
819         rxrpc_free_token_list(prep->payload.data[0]);
820 }
821 
822 /*
823  * Preparse a server secret key.
824  *
825  * The data should be the 8-byte secret key.
826  */
827 static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
828 {
829         struct crypto_skcipher *ci;
830 
831         _enter("%zu", prep->datalen);
832 
833         if (prep->datalen != 8)
834                 return -EINVAL;
835 
836         memcpy(&prep->payload.data[2], prep->data, 8);
837 
838         ci = crypto_alloc_skcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
839         if (IS_ERR(ci)) {
840                 _leave(" = %ld", PTR_ERR(ci));
841                 return PTR_ERR(ci);
842         }
843 
844         if (crypto_skcipher_setkey(ci, prep->data, 8) < 0)
845                 BUG();
846 
847         prep->payload.data[0] = ci;
848         _leave(" = 0");
849         return 0;
850 }
851 
852 /*
853  * Clean up preparse data.
854  */
855 static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
856 {
857         if (prep->payload.data[0])
858                 crypto_free_skcipher(prep->payload.data[0]);
859 }
860 
861 /*
862  * dispose of the data dangling from the corpse of a rxrpc key
863  */
864 static void rxrpc_destroy(struct key *key)
865 {
866         rxrpc_free_token_list(key->payload.data[0]);
867 }
868 
869 /*
870  * dispose of the data dangling from the corpse of a rxrpc key
871  */
872 static void rxrpc_destroy_s(struct key *key)
873 {
874         if (key->payload.data[0]) {
875                 crypto_free_skcipher(key->payload.data[0]);
876                 key->payload.data[0] = NULL;
877         }
878 }
879 
880 /*
881  * describe the rxrpc key
882  */
883 static void rxrpc_describe(const struct key *key, struct seq_file *m)
884 {
885         seq_puts(m, key->description);
886 }
887 
888 /*
889  * grab the security key for a socket
890  */
891 int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
892 {
893         struct key *key;
894         char *description;
895 
896         _enter("");
897 
898         if (optlen <= 0 || optlen > PAGE_SIZE - 1)
899                 return -EINVAL;
900 
901         description = memdup_user_nul(optval, optlen);
902         if (IS_ERR(description))
903                 return PTR_ERR(description);
904 
905         key = request_key(&key_type_rxrpc, description, NULL);
906         if (IS_ERR(key)) {
907                 kfree(description);
908                 _leave(" = %ld", PTR_ERR(key));
909                 return PTR_ERR(key);
910         }
911 
912         rx->key = key;
913         kfree(description);
914         _leave(" = 0 [key %x]", key->serial);
915         return 0;
916 }
917 
918 /*
919  * grab the security keyring for a server socket
920  */
921 int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
922                          int optlen)
923 {
924         struct key *key;
925         char *description;
926 
927         _enter("");
928 
929         if (optlen <= 0 || optlen > PAGE_SIZE - 1)
930                 return -EINVAL;
931 
932         description = memdup_user_nul(optval, optlen);
933         if (IS_ERR(description))
934                 return PTR_ERR(description);
935 
936         key = request_key(&key_type_keyring, description, NULL);
937         if (IS_ERR(key)) {
938                 kfree(description);
939                 _leave(" = %ld", PTR_ERR(key));
940                 return PTR_ERR(key);
941         }
942 
943         rx->securities = key;
944         kfree(description);
945         _leave(" = 0 [key %x]", key->serial);
946         return 0;
947 }
948 
949 /*
950  * generate a server data key
951  */
952 int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
953                               const void *session_key,
954                               time_t expiry,
955                               u32 kvno)
956 {
957         const struct cred *cred = current_cred();
958         struct key *key;
959         int ret;
960 
961         struct {
962                 u32 kver;
963                 struct rxrpc_key_data_v1 v1;
964         } data;
965 
966         _enter("");
967 
968         key = key_alloc(&key_type_rxrpc, "x",
969                         GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0,
970                         KEY_ALLOC_NOT_IN_QUOTA, NULL);
971         if (IS_ERR(key)) {
972                 _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
973                 return -ENOMEM;
974         }
975 
976         _debug("key %d", key_serial(key));
977 
978         data.kver = 1;
979         data.v1.security_index = RXRPC_SECURITY_RXKAD;
980         data.v1.ticket_length = 0;
981         data.v1.expiry = expiry;
982         data.v1.kvno = 0;
983 
984         memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
985 
986         ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
987         if (ret < 0)
988                 goto error;
989 
990         conn->params.key = key;
991         _leave(" = 0 [%d]", key_serial(key));
992         return 0;
993 
994 error:
995         key_revoke(key);
996         key_put(key);
997         _leave(" = -ENOMEM [ins %d]", ret);
998         return -ENOMEM;
999 }
1000 EXPORT_SYMBOL(rxrpc_get_server_data_key);
1001 
1002 /**
1003  * rxrpc_get_null_key - Generate a null RxRPC key
1004  * @keyname: The name to give the key.
1005  *
1006  * Generate a null RxRPC key that can be used to indicate anonymous security is
1007  * required for a particular domain.
1008  */
1009 struct key *rxrpc_get_null_key(const char *keyname)
1010 {
1011         const struct cred *cred = current_cred();
1012         struct key *key;
1013         int ret;
1014 
1015         key = key_alloc(&key_type_rxrpc, keyname,
1016                         GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
1017                         KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, NULL);
1018         if (IS_ERR(key))
1019                 return key;
1020 
1021         ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
1022         if (ret < 0) {
1023                 key_revoke(key);
1024                 key_put(key);
1025                 return ERR_PTR(ret);
1026         }
1027 
1028         return key;
1029 }
1030 EXPORT_SYMBOL(rxrpc_get_null_key);
1031 
1032 /*
1033  * read the contents of an rxrpc key
1034  * - this returns the result in XDR form
1035  */
1036 static long rxrpc_read(const struct key *key,
1037                        char __user *buffer, size_t buflen)
1038 {
1039         const struct rxrpc_key_token *token;
1040         const struct krb5_principal *princ;
1041         size_t size;
1042         __be32 __user *xdr, *oldxdr;
1043         u32 cnlen, toksize, ntoks, tok, zero;
1044         u16 toksizes[AFSTOKEN_MAX];
1045         int loop;
1046 
1047         _enter("");
1048 
1049         /* we don't know what form we should return non-AFS keys in */
1050         if (memcmp(key->description, "afs@", 4) != 0)
1051                 return -EOPNOTSUPP;
1052         cnlen = strlen(key->description + 4);
1053 
1054 #define RND(X) (((X) + 3) & ~3)
1055 
1056         /* AFS keys we return in XDR form, so we need to work out the size of
1057          * the XDR */
1058         size = 2 * 4;   /* flags, cellname len */
1059         size += RND(cnlen);     /* cellname */
1060         size += 1 * 4;  /* token count */
1061 
1062         ntoks = 0;
1063         for (token = key->payload.data[0]; token; token = token->next) {
1064                 toksize = 4;    /* sec index */
1065 
1066                 switch (token->security_index) {
1067                 case RXRPC_SECURITY_RXKAD:
1068                         toksize += 8 * 4;       /* viceid, kvno, key*2, begin,
1069                                                  * end, primary, tktlen */
1070                         toksize += RND(token->kad->ticket_len);
1071                         break;
1072 
1073                 case RXRPC_SECURITY_RXK5:
1074                         princ = &token->k5->client;
1075                         toksize += 4 + princ->n_name_parts * 4;
1076                         for (loop = 0; loop < princ->n_name_parts; loop++)
1077                                 toksize += RND(strlen(princ->name_parts[loop]));
1078                         toksize += 4 + RND(strlen(princ->realm));
1079 
1080                         princ = &token->k5->server;
1081                         toksize += 4 + princ->n_name_parts * 4;
1082                         for (loop = 0; loop < princ->n_name_parts; loop++)
1083                                 toksize += RND(strlen(princ->name_parts[loop]));
1084                         toksize += 4 + RND(strlen(princ->realm));
1085 
1086                         toksize += 8 + RND(token->k5->session.data_len);
1087 
1088                         toksize += 4 * 8 + 2 * 4;
1089 
1090                         toksize += 4 + token->k5->n_addresses * 8;
1091                         for (loop = 0; loop < token->k5->n_addresses; loop++)
1092                                 toksize += RND(token->k5->addresses[loop].data_len);
1093 
1094                         toksize += 4 + RND(token->k5->ticket_len);
1095                         toksize += 4 + RND(token->k5->ticket2_len);
1096 
1097                         toksize += 4 + token->k5->n_authdata * 8;
1098                         for (loop = 0; loop < token->k5->n_authdata; loop++)
1099                                 toksize += RND(token->k5->authdata[loop].data_len);
1100                         break;
1101 
1102                 default: /* we have a ticket we can't encode */
1103                         BUG();
1104                         continue;
1105                 }
1106 
1107                 _debug("token[%u]: toksize=%u", ntoks, toksize);
1108                 ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
1109 
1110                 toksizes[ntoks++] = toksize;
1111                 size += toksize + 4; /* each token has a length word */
1112         }
1113 
1114 #undef RND
1115 
1116         if (!buffer || buflen < size)
1117                 return size;
1118 
1119         xdr = (__be32 __user *) buffer;
1120         zero = 0;
1121 #define ENCODE(x)                               \
1122         do {                                    \
1123                 __be32 y = htonl(x);            \
1124                 if (put_user(y, xdr++) < 0)     \
1125                         goto fault;             \
1126         } while(0)
1127 #define ENCODE_DATA(l, s)                                               \
1128         do {                                                            \
1129                 u32 _l = (l);                                           \
1130                 ENCODE(l);                                              \
1131                 if (copy_to_user(xdr, (s), _l) != 0)                    \
1132                         goto fault;                                     \
1133                 if (_l & 3 &&                                           \
1134                     copy_to_user((u8 __user *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
1135                         goto fault;                                     \
1136                 xdr += (_l + 3) >> 2;                                   \
1137         } while(0)
1138 #define ENCODE64(x)                                     \
1139         do {                                            \
1140                 __be64 y = cpu_to_be64(x);              \
1141                 if (copy_to_user(xdr, &y, 8) != 0)      \
1142                         goto fault;                     \
1143                 xdr += 8 >> 2;                          \
1144         } while(0)
1145 #define ENCODE_STR(s)                           \
1146         do {                                    \
1147                 const char *_s = (s);           \
1148                 ENCODE_DATA(strlen(_s), _s);    \
1149         } while(0)
1150 
1151         ENCODE(0);                                      /* flags */
1152         ENCODE_DATA(cnlen, key->description + 4);       /* cellname */
1153         ENCODE(ntoks);
1154 
1155         tok = 0;
1156         for (token = key->payload.data[0]; token; token = token->next) {
1157                 toksize = toksizes[tok++];
1158                 ENCODE(toksize);
1159                 oldxdr = xdr;
1160                 ENCODE(token->security_index);
1161 
1162                 switch (token->security_index) {
1163                 case RXRPC_SECURITY_RXKAD:
1164                         ENCODE(token->kad->vice_id);
1165                         ENCODE(token->kad->kvno);
1166                         ENCODE_DATA(8, token->kad->session_key);
1167                         ENCODE(token->kad->start);
1168                         ENCODE(token->kad->expiry);
1169                         ENCODE(token->kad->primary_flag);
1170                         ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
1171                         break;
1172 
1173                 case RXRPC_SECURITY_RXK5:
1174                         princ = &token->k5->client;
1175                         ENCODE(princ->n_name_parts);
1176                         for (loop = 0; loop < princ->n_name_parts; loop++)
1177                                 ENCODE_STR(princ->name_parts[loop]);
1178                         ENCODE_STR(princ->realm);
1179 
1180                         princ = &token->k5->server;
1181                         ENCODE(princ->n_name_parts);
1182                         for (loop = 0; loop < princ->n_name_parts; loop++)
1183                                 ENCODE_STR(princ->name_parts[loop]);
1184                         ENCODE_STR(princ->realm);
1185 
1186                         ENCODE(token->k5->session.tag);
1187                         ENCODE_DATA(token->k5->session.data_len,
1188                                     token->k5->session.data);
1189 
1190                         ENCODE64(token->k5->authtime);
1191                         ENCODE64(token->k5->starttime);
1192                         ENCODE64(token->k5->endtime);
1193                         ENCODE64(token->k5->renew_till);
1194                         ENCODE(token->k5->is_skey);
1195                         ENCODE(token->k5->flags);
1196 
1197                         ENCODE(token->k5->n_addresses);
1198                         for (loop = 0; loop < token->k5->n_addresses; loop++) {
1199                                 ENCODE(token->k5->addresses[loop].tag);
1200                                 ENCODE_DATA(token->k5->addresses[loop].data_len,
1201                                             token->k5->addresses[loop].data);
1202                         }
1203 
1204                         ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
1205                         ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
1206 
1207                         ENCODE(token->k5->n_authdata);
1208                         for (loop = 0; loop < token->k5->n_authdata; loop++) {
1209                                 ENCODE(token->k5->authdata[loop].tag);
1210                                 ENCODE_DATA(token->k5->authdata[loop].data_len,
1211                                             token->k5->authdata[loop].data);
1212                         }
1213                         break;
1214 
1215                 default:
1216                         BUG();
1217                         break;
1218                 }
1219 
1220                 ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
1221                           toksize);
1222         }
1223 
1224 #undef ENCODE_STR
1225 #undef ENCODE_DATA
1226 #undef ENCODE64
1227 #undef ENCODE
1228 
1229         ASSERTCMP(tok, ==, ntoks);
1230         ASSERTCMP((char __user *) xdr - buffer, ==, size);
1231         _leave(" = %zu", size);
1232         return size;
1233 
1234 fault:
1235         _leave(" = -EFAULT");
1236         return -EFAULT;
1237 }
1238 

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