2 * COPYRIGHT (c) 2006 The Regents of the University of Michigan
5 * Copyright (c) 2012, 2014, Intel Corporation.
7 * Permission is granted to use, copy, create derivative works
8 * and redistribute this software and such derivative works
9 * for any purpose, so long as the name of The University of
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12 * without specific, written prior authorization. If the
13 * above copyright notice or any other identification of the
14 * University of Michigan is included in any copy of any
15 * portion of this software, then the disclaimer below must
18 * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
19 * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
20 * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
21 * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
22 * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
24 * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
25 * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
26 * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
27 * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
28 * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
35 * Newer versions of MIT and Heimdal have lucid context support.
36 * We can use common code if it is supported.
45 #include <gssapi/gssapi.h>
47 typedef uint64_t OM_uint64;
49 #include <gssapi/gssapi_krb5.h>
52 # include "lgss_utils.h"
54 # include "gss_util.h"
55 # include "gss_oids.h"
56 # include "err_util.h"
58 #include "write_bytes.h"
63 write_lucid_keyblock(char **p, char *end, gss_krb5_lucid_key_t *key)
67 if (WRITE_BYTES(p, end, key->type)) return -1;
68 tmp.length = key->length;
69 tmp.value = key->data;
70 if (write_buffer(p, end, &tmp)) return -1;
75 prepare_krb5_rfc1964_buffer(gss_krb5_lucid_context_v1_t *lctx,
79 static int constant_zero = 0;
80 unsigned char fakeseed[16] = { 0 };
81 uint32_t word_send_seq;
82 gss_krb5_lucid_key_t enc_key;
87 * The new Kerberos interface to get the gss context
88 * does not include the seed or seed_init fields
89 * because we never really use them. But for now,
90 * send down a fake buffer so we can use the same
91 * interface to the kernel.
93 memset(&enc_key, 0, sizeof(enc_key));
95 if (!(buf->value = calloc(1, MAX_CTX_LEN)))
98 end = buf->value + MAX_CTX_LEN;
100 if (WRITE_BYTES(&p, end, lctx->initiate)) goto out_err;
102 /* seed_init and seed not used by kernel anyway */
103 if (WRITE_BYTES(&p, end, constant_zero)) goto out_err;
104 if (write_bytes(&p, end, &fakeseed, 16)) goto out_err;
106 if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.sign_alg)) goto out_err;
107 if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.seal_alg)) goto out_err;
108 if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
109 word_send_seq = lctx->send_seq; /* XXX send_seq is 64-bit */
110 if (WRITE_BYTES(&p, end, word_send_seq)) goto out_err;
111 if (write_oid(&p, end, &krb5oid)) goto out_err;
115 * The kernel gss code expects des-cbc-raw for all flavors of des.
116 * The keytype from MIT has this type, but Heimdal does not.
117 * Force the Heimdal keytype to 4 (des-cbc-raw).
118 * Note that the rfc1964 version only supports DES enctypes.
120 if (lctx->rfc1964_kd.ctx_key.type != 4) {
121 printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
122 __FUNCTION__, lctx->rfc1964_kd.ctx_key.type, 4);
123 lctx->rfc1964_kd.ctx_key.type = 4;
126 printerr(2, "%s: serializing keys with enctype %d and length %d\n",
127 __FUNCTION__, lctx->rfc1964_kd.ctx_key.type,
128 lctx->rfc1964_kd.ctx_key.length);
130 /* derive the encryption key and copy it into buffer */
131 enc_key.type = lctx->rfc1964_kd.ctx_key.type;
132 enc_key.length = lctx->rfc1964_kd.ctx_key.length;
133 if ((enc_key.data = calloc(1, enc_key.length)) == NULL)
135 skd = (char *) lctx->rfc1964_kd.ctx_key.data;
136 dkd = (char *) enc_key.data;
137 for (i = 0; i < enc_key.length; i++)
138 dkd[i] = skd[i] ^ 0xf0;
139 if (write_lucid_keyblock(&p, end, &enc_key))
141 if (write_lucid_keyblock(&p, end, &lctx->rfc1964_kd.ctx_key))
145 buf->length = p - (char *)buf->value;
148 printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
154 if (enc_key.data) free(enc_key.data);
158 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
159 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
162 #define KG_USAGE_SEAL 22
163 #define KG_USAGE_SIGN 23
164 #define KG_USAGE_SEQ 24
167 #define KG_USAGE_ACCEPTOR_SEAL 22
168 #define KG_USAGE_ACCEPTOR_SIGN 23
169 #define KG_USAGE_INITIATOR_SEAL 24
170 #define KG_USAGE_INITIATOR_SIGN 25
172 /* Lifted from mit src/lib/gssapi/krb5/gssapiP_krb5.h */
174 SEAL_ALG_NONE = 0xffff,
175 SEAL_ALG_DES = 0x0000,
176 SEAL_ALG_1 = 0x0001, /* not published */
177 SEAL_ALG_MICROSOFT_RC4 = 0x0010, /* microsoft w2k; */
178 SEAL_ALG_DES3KD = 0x0002
181 #define KEY_USAGE_SEED_ENCRYPTION 0xAA
182 #define KEY_USAGE_SEED_INTEGRITY 0x55
183 #define KEY_USAGE_SEED_CHECKSUM 0x99
186 /* Flags for version 2 context flags */
187 #define KRB5_CTX_FLAG_INITIATOR 0x00000001
188 #define KRB5_CTX_FLAG_CFX 0x00000002
189 #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
191 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
192 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
194 * We don't have "legal" access to these MIT-only
195 * structures located in libk5crypto
197 extern void *krb5int_enc_arcfour;
198 #ifdef HAVE_DES3_SUPPORT
199 extern void *krb5int_enc_des3;
201 extern void *krb5int_enc_aes128;
202 extern void *krb5int_enc_aes256;
205 key_lucid_to_krb5(const gss_krb5_lucid_key_t *lin, krb5_keyblock *kout)
207 memset(kout, 0, sizeof(*kout));
209 kout->enctype = lin->type;
210 kout->length = lin->length;
211 kout->contents = lin->data;
213 kout->keytype = lin->type;
214 kout->keyvalue.length = lin->length;
215 kout->keyvalue.data = lin->data;
220 key_krb5_to_lucid(const krb5_keyblock *kin, gss_krb5_lucid_key_t *lout)
222 memset(lout, 0, sizeof(*lout));
225 lout->data = malloc(kin->length);
226 if (lout->data == NULL)
227 return KRB5_CC_NOMEM;
229 lout->type = kin->enctype;
230 lout->length = kin->length;
231 memcpy(lout->data, kin->contents, kin->length);
233 lout->data = malloc(kin->keyvalue.length);
234 if (lout->data == NULL)
235 return KRB5_CC_NOMEM;
237 lout->type = kin->keytype;
238 lout->length = kin->keyvalue.length;
239 memcpy(lout->data, kin->keyvalue.data, kin->keyvalue.length);
245 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
246 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
247 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
248 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
250 * Function to derive a new key from a given key and given constant data.
252 static krb5_error_code
253 derive_key_lucid(const gss_krb5_lucid_key_t *in, gss_krb5_lucid_key_t *out,
254 int usage, char extra)
256 krb5_error_code code;
257 unsigned char constant_data[K5CLENGTH];
259 int keylength __attribute__ ((unused));
263 krb5_keyblock kin; /* must send krb5_keyblock, not lucid! */
264 #if defined(HAVE_HEIMDAL) || HAVE_KRB5INT_DERIVE_KEY
265 krb5_context kcontext;
266 krb5_keyblock *outkey;
270 #if HAVE_KRB5INT_DERIVE_KEY
271 krb5_key key_in, key_out;
275 * XXX Hack alert. We don't have "legal" access to these
276 * values and structures located in libk5crypto
279 #ifdef HAVE_DES3_SUPPORT
280 case ENCTYPE_DES3_CBC_SHA1:
282 case ENCTYPE_DES3_CBC_RAW:
286 enc = &krb5int_enc_des3;
290 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
293 enc = &krb5int_enc_aes128;
296 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
299 enc = &krb5int_enc_aes256;
303 code = KRB5_BAD_ENCTYPE;
307 /* Convert to correct format for call to krb5_derive_key */
308 key_lucid_to_krb5(in, &kin);
310 datain.data = (char *) constant_data;
311 datain.length = K5CLENGTH;
313 ((char *)(datain.data))[0] = (usage>>24)&0xff;
314 ((char *)(datain.data))[1] = (usage>>16)&0xff;
315 ((char *)(datain.data))[2] = (usage>>8)&0xff;
316 ((char *)(datain.data))[3] = usage&0xff;
318 ((char *)(datain.data))[4] = (char) extra;
320 /* Step 1: Init context */
321 /* Heimdal and newer MIT Kerberos require kcontext */
322 #if defined(HAVE_KRB5INT_DERIVE_KEY) || defined(HAVE_HEIMDAL)
323 code = krb5_init_context(&kcontext);
328 /* Step 2: Get the derived key */
330 #if HAVE_KRB5INT_DERIVE_KEY
331 code = krb5_k_create_key(kcontext, &kin, &key_in);
335 code = ll_krb5int_derive_key(enc, key_in, &key_out, &datain,
338 krb5_k_free_key(kcontext, key_in);
340 krb5_k_key_keyblock(kcontext, key_out, &outkey);
341 krb5_k_free_key(kcontext, key_out);
343 #else /* !HAVE_KRB5INT_DERIVE_KEY */
344 out->length = keylength;
345 out->type = in->type;
347 key_lucid_to_krb5(out, &kout);
349 code = krb5_derive_key(enc, &kin, &kout, &datain);
350 #endif /* HAVE_KRB5INT_DERIVE_KEY */
351 #else /* !defined(HAVE_KRB5) */
352 code = krb5_derive_key(kcontext, &kin, in->type, constant_data, K5CLENGTH, &outkey);
353 #endif /* defined(HAVE_KRB5) */
358 /* Step 3: Copy the key to out */
359 #if defined(HAVE_KRB5INT_DERIVE_KEY) || defined(HAVE_HEIMDAL)
360 code = key_krb5_to_lucid(outkey, out);
361 krb5_free_keyblock(kcontext, outkey);
362 #else /* !defined(HAVE_KRB5) */
363 code = key_krb5_to_lucid(&kout, out);
364 #endif /* defined(HAVE_KRB5) */
366 /* Step 4: Free the context */
367 #if defined(HAVE_KRB5INT_DERIVE_KEY) || defined(HAVE_HEIMDAL)
368 krb5_free_context(kcontext);
373 printerr(0, "ERROR: %s: returning error %d (%s)\n",
374 __FUNCTION__, code, error_message(code));
380 * Prepare a new-style buffer, as defined in rfc4121 (a.k.a. cfx),
381 * to send to the kernel for newer encryption types -- or for DES3.
385 * u32 initiate; ( whether we are the initiator or not )
388 * #define KRB5_CTX_FLAG_INITIATOR 0x00000001
389 * #define KRB5_CTX_FLAG_CFX 0x00000002
390 * #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
392 * u32 enctype; ( encrption type of keys )
393 * u32 size_of_each_key; ( size of each key in bytes )
394 * u32 number_of_keys; ( N -- should always be 3 for now )
401 prepare_krb5_rfc4121_buffer(gss_krb5_lucid_context_v1_t *lctx,
402 gss_buffer_desc *buf)
404 static int constant_two = 2;
406 uint32_t v2_flags = 0;
407 gss_krb5_lucid_key_t enc_key;
408 gss_krb5_lucid_key_t derived_key;
409 gss_buffer_desc fakeoid;
414 memset(&enc_key, 0, sizeof(enc_key));
415 memset(&fakeoid, 0, sizeof(fakeoid));
417 if (!(buf->value = calloc(1, MAX_CTX_LEN)))
420 end = buf->value + MAX_CTX_LEN;
423 if (WRITE_BYTES(&p, end, constant_two)) goto out_err;
424 if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
427 v2_flags |= KRB5_CTX_FLAG_INITIATOR;
428 if (lctx->protocol != 0)
429 v2_flags |= KRB5_CTX_FLAG_CFX;
430 if (lctx->protocol != 0 && lctx->cfx_kd.have_acceptor_subkey == 1)
431 v2_flags |= KRB5_CTX_FLAG_ACCEPTOR_SUBKEY;
433 if (WRITE_BYTES(&p, end, v2_flags)) goto out_err;
435 if (WRITE_BYTES(&p, end, lctx->send_seq)) goto out_err;
437 /* Protocol 0 here implies DES3 or RC4 */
438 printerr(3, "protocol %d\n", lctx->protocol);
439 if (lctx->protocol == 0) {
440 enctype = lctx->rfc1964_kd.ctx_key.type;
443 * The kernel gss code expects ENCTYPE_DES3_CBC_RAW (6) for
444 * 3des keys, but Heimdal key has ENCTYPE_DES3_CBC_SHA1 (16).
445 * Force the Heimdal enctype to 6.
447 if (enctype == ENCTYPE_DES3_CBC_SHA1) {
448 printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
449 __FUNCTION__, enctype, 6);
454 keysize = lctx->rfc1964_kd.ctx_key.length;
455 numkeys = 3; /* XXX is always gonna be three? */
457 if (lctx->cfx_kd.have_acceptor_subkey) {
458 enctype = lctx->cfx_kd.acceptor_subkey.type;
459 keysize = lctx->cfx_kd.acceptor_subkey.length;
461 enctype = lctx->cfx_kd.ctx_key.type;
462 keysize = lctx->cfx_kd.ctx_key.length;
466 printerr(3, "serializing %d keys with enctype %d and size %d\n",
467 numkeys, enctype, keysize);
468 if (WRITE_BYTES(&p, end, enctype)) goto out_err;
469 if (WRITE_BYTES(&p, end, keysize)) goto out_err;
470 if (WRITE_BYTES(&p, end, numkeys)) goto out_err;
472 if (lctx->protocol == 0) {
473 /* derive and send down: Ke, Ki, and Kc */
475 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
476 lctx->rfc1964_kd.ctx_key.length))
480 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
481 lctx->rfc1964_kd.ctx_key.length))
486 * RC4 is special, it dosen't need key derivation. Actually
487 * the Ke is based on plain text. Here we just let all three
488 * key identical, kernel will handle everything. --ericm
490 if (lctx->rfc1964_kd.ctx_key.type == ENCTYPE_ARCFOUR_HMAC) {
491 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
492 lctx->rfc1964_kd.ctx_key.length))
495 if (derive_key_lucid(&lctx->rfc1964_kd.ctx_key,
497 KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM))
499 if (write_bytes(&p, end, derived_key.data,
502 free(derived_key.data);
505 gss_krb5_lucid_key_t *keyptr;
506 uint32_t sign_usage, seal_usage;
508 if (lctx->cfx_kd.have_acceptor_subkey)
509 keyptr = &lctx->cfx_kd.acceptor_subkey;
511 keyptr = &lctx->cfx_kd.ctx_key;
514 * These are from rfc4142, but I don't understand:
515 * if we supply different 'usage' value for client &
516 * server, then the peers will have different derived
517 * keys. How could this work?
519 * Here we simply use old SIGN/SEAL values until we
520 * find the answer. --ericm
523 sign_usage = KG_USAGE_SIGN;
524 seal_usage = KG_USAGE_SEAL;
526 /* derive and send down: Ke, Ki, and Kc */
529 if (derive_key_lucid(keyptr, &derived_key,
530 seal_usage, KEY_USAGE_SEED_ENCRYPTION))
532 if (write_bytes(&p, end, derived_key.data,
535 free(derived_key.data);
538 if (derive_key_lucid(keyptr, &derived_key,
539 seal_usage, KEY_USAGE_SEED_INTEGRITY))
541 if (write_bytes(&p, end, derived_key.data,
544 free(derived_key.data);
547 if (derive_key_lucid(keyptr, &derived_key,
548 sign_usage, KEY_USAGE_SEED_CHECKSUM))
550 if (write_bytes(&p, end, derived_key.data,
553 free(derived_key.data);
556 buf->length = p - (char *)buf->value;
560 printerr(0, "ERROR: %s: failed serializing krb5 context for kernel\n",
574 serialize_krb5_ctx(gss_ctx_id_t *ctx, gss_buffer_desc *buf)
576 OM_uint32 maj_stat, min_stat;
577 void *return_ctx = 0;
579 gss_krb5_lucid_context_v1_t *lctx = 0;
582 printerr(3, "lucid version!\n");
583 maj_stat = gss_krb5_export_lucid_sec_context(&min_stat, ctx,
585 if (maj_stat != GSS_S_COMPLETE) {
586 pgsserr("gss_krb5_export_lucid_sec_context",
587 maj_stat, min_stat, &krb5oid);
591 /* Check the version returned, we only support v1 right now */
592 vers = ((gss_krb5_lucid_context_version_t *)return_ctx)->version;
595 lctx = (gss_krb5_lucid_context_v1_t *) return_ctx;
598 printerr(0, "ERROR: unsupported lucid sec context version %d\n",
605 * Now lctx points to a lucid context that we can send down to kernel
607 * Note: we send down different information to the kernel depending
608 * on the protocol version and the enctyption type.
609 * For protocol version 0 with all enctypes besides DES3, we use
610 * the original format. For protocol version != 0 or DES3, we
611 * send down the new style information.
614 if (lctx->protocol == 0 && lctx->rfc1964_kd.ctx_key.type <= 4)
615 retcode = prepare_krb5_rfc1964_buffer(lctx, buf);
617 retcode = prepare_krb5_rfc4121_buffer(lctx, buf);
619 maj_stat = gss_krb5_free_lucid_sec_context(&min_stat, return_ctx);
620 if (maj_stat != GSS_S_COMPLETE) {
621 pgsserr("gss_krb5_export_lucid_sec_context",
622 maj_stat, min_stat, &krb5oid);
623 printerr(0, "WARN: failed to free lucid sec context\n");
627 printerr(1, "%s: prepare_krb5_*_buffer failed (retcode = %d)\n",
628 __FUNCTION__, retcode);
635 printerr(0, "ERROR: failed serializing krb5 context for kernel\n");