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33 #ifdef HAVE_LUCID_CONTEXT_SUPPORT
36 * Newer versions of MIT and Heimdal have lucid context support.
37 * We can use common code if it is supported.
46 #include <gssapi/gssapi.h>
48 typedef uint64_t OM_uint64;
50 #include <gssapi/gssapi_krb5.h>
53 # include "lgss_utils.h"
55 # include "gss_util.h"
56 # include "gss_oids.h"
57 # include "err_util.h"
59 #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];
81 uint32_t word_send_seq;
82 gss_krb5_lucid_key_t enc_key;
85 gss_buffer_desc fakeoid;
88 * The new Kerberos interface to get the gss context
89 * does not include the seed or seed_init fields
90 * because we never really use them. But for now,
91 * send down a fake buffer so we can use the same
92 * interface to the kernel.
94 memset(&enc_key, 0, sizeof(enc_key));
95 memset(&fakeoid, 0, sizeof(fakeoid));
97 if (!(buf->value = calloc(1, MAX_CTX_LEN)))
100 end = buf->value + MAX_CTX_LEN;
102 if (WRITE_BYTES(&p, end, lctx->initiate)) goto out_err;
104 /* seed_init and seed not used by kernel anyway */
105 if (WRITE_BYTES(&p, end, constant_zero)) goto out_err;
106 if (write_bytes(&p, end, &fakeseed, 16)) goto out_err;
108 if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.sign_alg)) goto out_err;
109 if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.seal_alg)) goto out_err;
110 if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
111 word_send_seq = lctx->send_seq; /* XXX send_seq is 64-bit */
112 if (WRITE_BYTES(&p, end, word_send_seq)) goto out_err;
113 if (write_oid(&p, end, &krb5oid)) goto out_err;
117 * The kernel gss code expects des-cbc-raw for all flavors of des.
118 * The keytype from MIT has this type, but Heimdal does not.
119 * Force the Heimdal keytype to 4 (des-cbc-raw).
120 * Note that the rfc1964 version only supports DES enctypes.
122 if (lctx->rfc1964_kd.ctx_key.type != 4) {
123 printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
124 __FUNCTION__, lctx->rfc1964_kd.ctx_key.type, 4);
125 lctx->rfc1964_kd.ctx_key.type = 4;
128 printerr(2, "%s: serializing keys with enctype %d and length %d\n",
129 __FUNCTION__, lctx->rfc1964_kd.ctx_key.type,
130 lctx->rfc1964_kd.ctx_key.length);
132 /* derive the encryption key and copy it into buffer */
133 enc_key.type = lctx->rfc1964_kd.ctx_key.type;
134 enc_key.length = lctx->rfc1964_kd.ctx_key.length;
135 if ((enc_key.data = calloc(1, enc_key.length)) == NULL)
137 skd = (char *) lctx->rfc1964_kd.ctx_key.data;
138 dkd = (char *) enc_key.data;
139 for (i = 0; i < enc_key.length; i++)
140 dkd[i] = skd[i] ^ 0xf0;
141 if (write_lucid_keyblock(&p, end, &enc_key)) {
147 if (write_lucid_keyblock(&p, end, &lctx->rfc1964_kd.ctx_key))
150 buf->length = p - (char *)buf->value;
153 printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
154 if (buf->value) free(buf->value);
156 if (enc_key.data) free(enc_key.data);
160 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
161 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
164 #define KG_USAGE_SEAL 22
165 #define KG_USAGE_SIGN 23
166 #define KG_USAGE_SEQ 24
169 #define KG_USAGE_ACCEPTOR_SEAL 22
170 #define KG_USAGE_ACCEPTOR_SIGN 23
171 #define KG_USAGE_INITIATOR_SEAL 24
172 #define KG_USAGE_INITIATOR_SIGN 25
174 /* Lifted from mit src/lib/gssapi/krb5/gssapiP_krb5.h */
176 SEAL_ALG_NONE = 0xffff,
177 SEAL_ALG_DES = 0x0000,
178 SEAL_ALG_1 = 0x0001, /* not published */
179 SEAL_ALG_MICROSOFT_RC4 = 0x0010, /* microsoft w2k; */
180 SEAL_ALG_DES3KD = 0x0002
183 #define KEY_USAGE_SEED_ENCRYPTION 0xAA
184 #define KEY_USAGE_SEED_INTEGRITY 0x55
185 #define KEY_USAGE_SEED_CHECKSUM 0x99
188 /* Flags for version 2 context flags */
189 #define KRB5_CTX_FLAG_INITIATOR 0x00000001
190 #define KRB5_CTX_FLAG_CFX 0x00000002
191 #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
193 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
194 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
196 * We don't have "legal" access to these MIT-only
197 * structures located in libk5crypto
199 extern void krb5int_enc_arcfour;
200 extern void krb5int_enc_des3;
201 extern void krb5int_enc_aes128;
202 extern void krb5int_enc_aes256;
203 extern int krb5_derive_key();
206 key_lucid_to_krb5(const gss_krb5_lucid_key_t *lin, krb5_keyblock *kout)
208 memset(kout, '\0', sizeof(kout));
210 kout->enctype = lin->type;
211 kout->length = lin->length;
212 kout->contents = lin->data;
214 kout->keytype = lin->type;
215 kout->keyvalue.length = lin->length;
216 kout->keyvalue.data = lin->data;
221 key_krb5_to_lucid(const krb5_keyblock *kin, gss_krb5_lucid_key_t *lout)
223 memset(lout, '\0', sizeof(lout));
225 lout->type = kin->enctype;
226 lout->length = kin->length;
227 lout->data = kin->contents;
229 lout->type = kin->keytype;
230 lout->length = kin->keyvalue.length;
231 memcpy(lout->data, kin->keyvalue.data, kin->keyvalue.length);
235 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
236 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
237 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
238 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
240 * Function to derive a new key from a given key and given constant data.
242 static krb5_error_code
243 derive_key_lucid(const gss_krb5_lucid_key_t *in, gss_krb5_lucid_key_t *out,
244 int usage, char extra)
246 krb5_error_code code;
247 unsigned char constant_data[K5CLENGTH];
251 krb5_keyblock kin, kout; /* must send krb5_keyblock, not lucid! */
253 krb5_context kcontext;
254 krb5_keyblock *outkey;
258 * XXX Hack alert. We don't have "legal" access to these
259 * values and structures located in libk5crypto
262 case ENCTYPE_DES3_CBC_SHA1:
264 case ENCTYPE_DES3_CBC_RAW:
268 enc = &krb5int_enc_des3;
271 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
274 enc = &krb5int_enc_aes128;
277 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
280 enc = &krb5int_enc_aes256;
284 code = KRB5_BAD_ENCTYPE;
288 /* allocate memory for output key */
289 if ((out->data = malloc(keylength)) == NULL) {
293 out->length = keylength;
294 out->type = in->type;
296 /* Convert to correct format for call to krb5_derive_key */
297 key_lucid_to_krb5(in, &kin);
298 key_lucid_to_krb5(out, &kout);
300 datain.data = (char *) constant_data;
301 datain.length = K5CLENGTH;
303 ((char *)(datain.data))[0] = (usage>>24)&0xff;
304 ((char *)(datain.data))[1] = (usage>>16)&0xff;
305 ((char *)(datain.data))[2] = (usage>>8)&0xff;
306 ((char *)(datain.data))[3] = usage&0xff;
308 ((char *)(datain.data))[4] = (char) extra;
311 code = krb5_derive_key(enc, &kin, &kout, &datain);
313 if ((code = krb5_init_context(&kcontext))) {
315 code = krb5_derive_key(kcontext, &kin, in->type, constant_data, K5CLENGTH, &outkey);
323 key_krb5_to_lucid(&kout, out);
325 key_krb5_to_lucid(outkey, out);
326 krb5_free_keyblock(kcontext, outkey);
327 krb5_free_context(kcontext);
332 printerr(0, "ERROR: %s: returning error %d (%s)\n",
333 __FUNCTION__, code, error_message(code));
339 * Prepare a new-style buffer, as defined in rfc4121 (a.k.a. cfx),
340 * to send to the kernel for newer encryption types -- or for DES3.
344 * u32 initiate; ( whether we are the initiator or not )
347 * #define KRB5_CTX_FLAG_INITIATOR 0x00000001
348 * #define KRB5_CTX_FLAG_CFX 0x00000002
349 * #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
351 * u32 enctype; ( encrption type of keys )
352 * u32 size_of_each_key; ( size of each key in bytes )
353 * u32 number_of_keys; ( N -- should always be 3 for now )
360 prepare_krb5_rfc4121_buffer(gss_krb5_lucid_context_v1_t *lctx,
361 gss_buffer_desc *buf)
363 static int constant_two = 2;
365 uint32_t v2_flags = 0;
366 gss_krb5_lucid_key_t enc_key;
367 gss_krb5_lucid_key_t derived_key;
368 gss_buffer_desc fakeoid;
373 memset(&enc_key, 0, sizeof(enc_key));
374 memset(&fakeoid, 0, sizeof(fakeoid));
376 if (!(buf->value = calloc(1, MAX_CTX_LEN)))
379 end = buf->value + MAX_CTX_LEN;
382 if (WRITE_BYTES(&p, end, constant_two)) goto out_err;
383 if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
386 v2_flags |= KRB5_CTX_FLAG_INITIATOR;
387 if (lctx->protocol != 0)
388 v2_flags |= KRB5_CTX_FLAG_CFX;
389 if (lctx->protocol != 0 && lctx->cfx_kd.have_acceptor_subkey == 1)
390 v2_flags |= KRB5_CTX_FLAG_ACCEPTOR_SUBKEY;
392 if (WRITE_BYTES(&p, end, v2_flags)) goto out_err;
394 if (WRITE_BYTES(&p, end, lctx->send_seq)) goto out_err;
396 /* Protocol 0 here implies DES3 or RC4 */
397 printerr(3, "protocol %d\n", lctx->protocol);
398 if (lctx->protocol == 0) {
399 enctype = lctx->rfc1964_kd.ctx_key.type;
402 * The kernel gss code expects ENCTYPE_DES3_CBC_RAW (6) for
403 * 3des keys, but Heimdal key has ENCTYPE_DES3_CBC_SHA1 (16).
404 * Force the Heimdal enctype to 6.
406 if (enctype == ENCTYPE_DES3_CBC_SHA1) {
407 printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
408 __FUNCTION__, enctype, 6);
413 keysize = lctx->rfc1964_kd.ctx_key.length;
414 numkeys = 3; /* XXX is always gonna be three? */
416 if (lctx->cfx_kd.have_acceptor_subkey) {
417 enctype = lctx->cfx_kd.acceptor_subkey.type;
418 keysize = lctx->cfx_kd.acceptor_subkey.length;
420 enctype = lctx->cfx_kd.ctx_key.type;
421 keysize = lctx->cfx_kd.ctx_key.length;
425 printerr(3, "serializing %d keys with enctype %d and size %d\n",
426 numkeys, enctype, keysize);
427 if (WRITE_BYTES(&p, end, enctype)) goto out_err;
428 if (WRITE_BYTES(&p, end, keysize)) goto out_err;
429 if (WRITE_BYTES(&p, end, numkeys)) goto out_err;
431 if (lctx->protocol == 0) {
432 /* derive and send down: Ke, Ki, and Kc */
434 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
435 lctx->rfc1964_kd.ctx_key.length))
439 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
440 lctx->rfc1964_kd.ctx_key.length))
445 * RC4 is special, it dosen't need key derivation. Actually
446 * the Ke is based on plain text. Here we just let all three
447 * key identical, kernel will handle everything. --ericm
449 if (lctx->rfc1964_kd.ctx_key.type == ENCTYPE_ARCFOUR_HMAC) {
450 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
451 lctx->rfc1964_kd.ctx_key.length))
454 if (derive_key_lucid(&lctx->rfc1964_kd.ctx_key,
456 KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM))
458 if (write_bytes(&p, end, derived_key.data,
461 free(derived_key.data);
464 gss_krb5_lucid_key_t *keyptr;
465 uint32_t sign_usage, seal_usage;
467 if (lctx->cfx_kd.have_acceptor_subkey)
468 keyptr = &lctx->cfx_kd.acceptor_subkey;
470 keyptr = &lctx->cfx_kd.ctx_key;
473 if (lctx->initiate == 1) {
474 sign_usage = KG_USAGE_INITIATOR_SIGN;
475 seal_usage = KG_USAGE_INITIATOR_SEAL;
477 sign_usage = KG_USAGE_ACCEPTOR_SIGN;
478 seal_usage = KG_USAGE_ACCEPTOR_SEAL;
482 * These are from rfc4142, but I don't understand: if we supply
483 * different 'usage' value for client & server, then the peers
484 * will have different derived keys. How could this work?
486 * Here we simply use old SIGN/SEAL values until we find the
490 sign_usage = KG_USAGE_SIGN;
491 seal_usage = KG_USAGE_SEAL;
494 /* derive and send down: Ke, Ki, and Kc */
497 if (derive_key_lucid(keyptr, &derived_key,
498 seal_usage, KEY_USAGE_SEED_ENCRYPTION))
500 if (write_bytes(&p, end, derived_key.data,
503 free(derived_key.data);
506 if (derive_key_lucid(keyptr, &derived_key,
507 seal_usage, KEY_USAGE_SEED_INTEGRITY))
509 if (write_bytes(&p, end, derived_key.data,
512 free(derived_key.data);
515 if (derive_key_lucid(keyptr, &derived_key,
516 sign_usage, KEY_USAGE_SEED_CHECKSUM))
518 if (write_bytes(&p, end, derived_key.data,
521 free(derived_key.data);
524 buf->length = p - (char *)buf->value;
528 printerr(0, "ERROR: %s: failed serializing krb5 context for kernel\n",
542 serialize_krb5_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf)
544 OM_uint32 maj_stat, min_stat;
545 void *return_ctx = 0;
547 gss_krb5_lucid_context_v1_t *lctx = 0;
550 printerr(3, "lucid version!\n");
551 maj_stat = gss_export_lucid_sec_context(&min_stat, &ctx,
553 if (maj_stat != GSS_S_COMPLETE) {
554 pgsserr("gss_export_lucid_sec_context",
555 maj_stat, min_stat, &krb5oid);
559 /* Check the version returned, we only support v1 right now */
560 vers = ((gss_krb5_lucid_context_version_t *)return_ctx)->version;
563 lctx = (gss_krb5_lucid_context_v1_t *) return_ctx;
566 printerr(0, "ERROR: unsupported lucid sec context version %d\n",
573 * Now lctx points to a lucid context that we can send down to kernel
575 * Note: we send down different information to the kernel depending
576 * on the protocol version and the enctyption type.
577 * For protocol version 0 with all enctypes besides DES3, we use
578 * the original format. For protocol version != 0 or DES3, we
579 * send down the new style information.
582 if (lctx->protocol == 0 && lctx->rfc1964_kd.ctx_key.type <= 4)
583 retcode = prepare_krb5_rfc1964_buffer(lctx, buf);
585 retcode = prepare_krb5_rfc4121_buffer(lctx, buf);
587 maj_stat = gss_free_lucid_sec_context(&min_stat, ctx, return_ctx);
588 if (maj_stat != GSS_S_COMPLETE) {
589 pgsserr("gss_export_lucid_sec_context",
590 maj_stat, min_stat, &krb5oid);
591 printerr(0, "WARN: failed to free lucid sec context\n");
595 printerr(1, "%s: prepare_krb5_*_buffer failed (retcode = %d)\n",
596 __FUNCTION__, retcode);
603 printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
609 #endif /* HAVE_LUCID_CONTEXT_SUPPORT */