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27 * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
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"
62 extern OM_uint32 gss_export_lucid_sec_context(OM_uint32 *min_stat,
66 extern OM_uint32 gss_free_lucid_sec_context(OM_uint32 *min_stat,
71 write_lucid_keyblock(char **p, char *end, gss_krb5_lucid_key_t *key)
75 if (WRITE_BYTES(p, end, key->type)) return -1;
76 tmp.length = key->length;
77 tmp.value = key->data;
78 if (write_buffer(p, end, &tmp)) return -1;
83 prepare_krb5_rfc1964_buffer(gss_krb5_lucid_context_v1_t *lctx,
87 static int constant_zero = 0;
88 unsigned char fakeseed[16] = { 0 };
89 uint32_t word_send_seq;
90 gss_krb5_lucid_key_t enc_key;
95 * The new Kerberos interface to get the gss context
96 * does not include the seed or seed_init fields
97 * because we never really use them. But for now,
98 * send down a fake buffer so we can use the same
99 * interface to the kernel.
101 memset(&enc_key, 0, sizeof(enc_key));
103 if (!(buf->value = calloc(1, MAX_CTX_LEN)))
106 end = buf->value + MAX_CTX_LEN;
108 if (WRITE_BYTES(&p, end, lctx->initiate)) goto out_err;
110 /* seed_init and seed not used by kernel anyway */
111 if (WRITE_BYTES(&p, end, constant_zero)) goto out_err;
112 if (write_bytes(&p, end, &fakeseed, 16)) goto out_err;
114 if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.sign_alg)) goto out_err;
115 if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.seal_alg)) goto out_err;
116 if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
117 word_send_seq = lctx->send_seq; /* XXX send_seq is 64-bit */
118 if (WRITE_BYTES(&p, end, word_send_seq)) goto out_err;
119 if (write_oid(&p, end, &krb5oid)) goto out_err;
123 * The kernel gss code expects des-cbc-raw for all flavors of des.
124 * The keytype from MIT has this type, but Heimdal does not.
125 * Force the Heimdal keytype to 4 (des-cbc-raw).
126 * Note that the rfc1964 version only supports DES enctypes.
128 if (lctx->rfc1964_kd.ctx_key.type != 4) {
129 printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
130 __FUNCTION__, lctx->rfc1964_kd.ctx_key.type, 4);
131 lctx->rfc1964_kd.ctx_key.type = 4;
134 printerr(2, "%s: serializing keys with enctype %d and length %d\n",
135 __FUNCTION__, lctx->rfc1964_kd.ctx_key.type,
136 lctx->rfc1964_kd.ctx_key.length);
138 /* derive the encryption key and copy it into buffer */
139 enc_key.type = lctx->rfc1964_kd.ctx_key.type;
140 enc_key.length = lctx->rfc1964_kd.ctx_key.length;
141 if ((enc_key.data = calloc(1, enc_key.length)) == NULL)
143 skd = (char *) lctx->rfc1964_kd.ctx_key.data;
144 dkd = (char *) enc_key.data;
145 for (i = 0; i < enc_key.length; i++)
146 dkd[i] = skd[i] ^ 0xf0;
147 if (write_lucid_keyblock(&p, end, &enc_key))
149 if (write_lucid_keyblock(&p, end, &lctx->rfc1964_kd.ctx_key))
153 buf->length = p - (char *)buf->value;
156 printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
162 if (enc_key.data) free(enc_key.data);
166 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
167 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
170 #define KG_USAGE_SEAL 22
171 #define KG_USAGE_SIGN 23
172 #define KG_USAGE_SEQ 24
175 #define KG_USAGE_ACCEPTOR_SEAL 22
176 #define KG_USAGE_ACCEPTOR_SIGN 23
177 #define KG_USAGE_INITIATOR_SEAL 24
178 #define KG_USAGE_INITIATOR_SIGN 25
180 /* Lifted from mit src/lib/gssapi/krb5/gssapiP_krb5.h */
182 SEAL_ALG_NONE = 0xffff,
183 SEAL_ALG_DES = 0x0000,
184 SEAL_ALG_1 = 0x0001, /* not published */
185 SEAL_ALG_MICROSOFT_RC4 = 0x0010, /* microsoft w2k; */
186 SEAL_ALG_DES3KD = 0x0002
189 #define KEY_USAGE_SEED_ENCRYPTION 0xAA
190 #define KEY_USAGE_SEED_INTEGRITY 0x55
191 #define KEY_USAGE_SEED_CHECKSUM 0x99
194 /* Flags for version 2 context flags */
195 #define KRB5_CTX_FLAG_INITIATOR 0x00000001
196 #define KRB5_CTX_FLAG_CFX 0x00000002
197 #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
199 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
200 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
202 * We don't have "legal" access to these MIT-only
203 * structures located in libk5crypto
205 extern void *krb5int_enc_arcfour;
206 extern void *krb5int_enc_des3;
207 extern void *krb5int_enc_aes128;
208 extern void *krb5int_enc_aes256;
211 key_lucid_to_krb5(const gss_krb5_lucid_key_t *lin, krb5_keyblock *kout)
213 memset(kout, 0, sizeof(*kout));
215 kout->enctype = lin->type;
216 kout->length = lin->length;
217 kout->contents = lin->data;
219 kout->keytype = lin->type;
220 kout->keyvalue.length = lin->length;
221 kout->keyvalue.data = lin->data;
226 key_krb5_to_lucid(const krb5_keyblock *kin, gss_krb5_lucid_key_t *lout)
228 memset(lout, 0, sizeof(*lout));
230 lout->type = kin->enctype;
231 lout->length = kin->length;
232 lout->data = kin->contents;
234 lout->type = kin->keytype;
235 lout->length = kin->keyvalue.length;
236 memcpy(lout->data, kin->keyvalue.data, kin->keyvalue.length);
240 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
241 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
242 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
243 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
245 * Function to derive a new key from a given key and given constant data.
247 static krb5_error_code
248 derive_key_lucid(const gss_krb5_lucid_key_t *in, gss_krb5_lucid_key_t *out,
249 int usage, char extra)
251 krb5_error_code code;
252 unsigned char constant_data[K5CLENGTH];
256 krb5_keyblock kin, kout; /* must send krb5_keyblock, not lucid! */
257 #if defined(HAVE_HEIMDAL) || HAVE_KRB5INT_DERIVE_KEY
258 krb5_context kcontext;
260 #if HAVE_KRB5INT_DERIVE_KEY
261 krb5_key key_in, key_out;
264 krb5_keyblock *outkey;
268 * XXX Hack alert. We don't have "legal" access to these
269 * values and structures located in libk5crypto
272 case ENCTYPE_DES3_CBC_SHA1:
274 case ENCTYPE_DES3_CBC_RAW:
278 enc = &krb5int_enc_des3;
281 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
284 enc = &krb5int_enc_aes128;
287 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
290 enc = &krb5int_enc_aes256;
294 code = KRB5_BAD_ENCTYPE;
298 /* allocate memory for output key */
299 if ((out->data = malloc(keylength)) == NULL) {
303 out->length = keylength;
304 out->type = in->type;
306 /* Convert to correct format for call to krb5_derive_key */
307 key_lucid_to_krb5(in, &kin);
308 key_lucid_to_krb5(out, &kout);
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;
321 #if HAVE_KRB5INT_DERIVE_KEY
322 code = krb5_init_context(&kcontext);
328 code = krb5_k_create_key(kcontext, &kin, &key_in);
334 code = krb5_k_create_key(kcontext, &kout, &key_out);
340 code = krb5int_derive_key(enc, key_in, &key_out, &datain,
342 #else /* !HAVE_KRB5INT_DERIVE_KEY */
343 code = krb5_derive_key(enc, &kin, &kout, &datain);
344 #endif /* HAVE_KRB5INT_DERIVE_KEY */
345 #else /* !defined(HAVE_KRB5) */
346 if ((code = krb5_init_context(&kcontext))) {
348 code = krb5_derive_key(kcontext, &kin, in->type, constant_data, K5CLENGTH, &outkey);
349 #endif /* defined(HAVE_KRB5) */
356 key_krb5_to_lucid(&kout, out);
357 #if HAVE_KRB5INT_DERIVE_KEY
358 krb5_free_context(kcontext);
359 #endif /* HAVE_KRB5INT_DERIVE_KEY */
360 #else /* !defined(HAVE_KRB5) */
361 key_krb5_to_lucid(outkey, out);
362 krb5_free_keyblock(kcontext, outkey);
363 krb5_free_context(kcontext);
364 #endif /* defined(HAVE_KRB5) */
368 printerr(0, "ERROR: %s: returning error %d (%s)\n",
369 __FUNCTION__, code, error_message(code));
375 * Prepare a new-style buffer, as defined in rfc4121 (a.k.a. cfx),
376 * to send to the kernel for newer encryption types -- or for DES3.
380 * u32 initiate; ( whether we are the initiator or not )
383 * #define KRB5_CTX_FLAG_INITIATOR 0x00000001
384 * #define KRB5_CTX_FLAG_CFX 0x00000002
385 * #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
387 * u32 enctype; ( encrption type of keys )
388 * u32 size_of_each_key; ( size of each key in bytes )
389 * u32 number_of_keys; ( N -- should always be 3 for now )
396 prepare_krb5_rfc4121_buffer(gss_krb5_lucid_context_v1_t *lctx,
397 gss_buffer_desc *buf)
399 static int constant_two = 2;
401 uint32_t v2_flags = 0;
402 gss_krb5_lucid_key_t enc_key;
403 gss_krb5_lucid_key_t derived_key;
404 gss_buffer_desc fakeoid;
409 memset(&enc_key, 0, sizeof(enc_key));
410 memset(&fakeoid, 0, sizeof(fakeoid));
412 if (!(buf->value = calloc(1, MAX_CTX_LEN)))
415 end = buf->value + MAX_CTX_LEN;
418 if (WRITE_BYTES(&p, end, constant_two)) goto out_err;
419 if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
422 v2_flags |= KRB5_CTX_FLAG_INITIATOR;
423 if (lctx->protocol != 0)
424 v2_flags |= KRB5_CTX_FLAG_CFX;
425 if (lctx->protocol != 0 && lctx->cfx_kd.have_acceptor_subkey == 1)
426 v2_flags |= KRB5_CTX_FLAG_ACCEPTOR_SUBKEY;
428 if (WRITE_BYTES(&p, end, v2_flags)) goto out_err;
430 if (WRITE_BYTES(&p, end, lctx->send_seq)) goto out_err;
432 /* Protocol 0 here implies DES3 or RC4 */
433 printerr(3, "protocol %d\n", lctx->protocol);
434 if (lctx->protocol == 0) {
435 enctype = lctx->rfc1964_kd.ctx_key.type;
438 * The kernel gss code expects ENCTYPE_DES3_CBC_RAW (6) for
439 * 3des keys, but Heimdal key has ENCTYPE_DES3_CBC_SHA1 (16).
440 * Force the Heimdal enctype to 6.
442 if (enctype == ENCTYPE_DES3_CBC_SHA1) {
443 printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
444 __FUNCTION__, enctype, 6);
449 keysize = lctx->rfc1964_kd.ctx_key.length;
450 numkeys = 3; /* XXX is always gonna be three? */
452 if (lctx->cfx_kd.have_acceptor_subkey) {
453 enctype = lctx->cfx_kd.acceptor_subkey.type;
454 keysize = lctx->cfx_kd.acceptor_subkey.length;
456 enctype = lctx->cfx_kd.ctx_key.type;
457 keysize = lctx->cfx_kd.ctx_key.length;
461 printerr(3, "serializing %d keys with enctype %d and size %d\n",
462 numkeys, enctype, keysize);
463 if (WRITE_BYTES(&p, end, enctype)) goto out_err;
464 if (WRITE_BYTES(&p, end, keysize)) goto out_err;
465 if (WRITE_BYTES(&p, end, numkeys)) goto out_err;
467 if (lctx->protocol == 0) {
468 /* derive and send down: Ke, Ki, and Kc */
470 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
471 lctx->rfc1964_kd.ctx_key.length))
475 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
476 lctx->rfc1964_kd.ctx_key.length))
481 * RC4 is special, it dosen't need key derivation. Actually
482 * the Ke is based on plain text. Here we just let all three
483 * key identical, kernel will handle everything. --ericm
485 if (lctx->rfc1964_kd.ctx_key.type == ENCTYPE_ARCFOUR_HMAC) {
486 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
487 lctx->rfc1964_kd.ctx_key.length))
490 if (derive_key_lucid(&lctx->rfc1964_kd.ctx_key,
492 KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM))
494 if (write_bytes(&p, end, derived_key.data,
497 free(derived_key.data);
500 gss_krb5_lucid_key_t *keyptr;
501 uint32_t sign_usage, seal_usage;
503 if (lctx->cfx_kd.have_acceptor_subkey)
504 keyptr = &lctx->cfx_kd.acceptor_subkey;
506 keyptr = &lctx->cfx_kd.ctx_key;
509 if (lctx->initiate == 1) {
510 sign_usage = KG_USAGE_INITIATOR_SIGN;
511 seal_usage = KG_USAGE_INITIATOR_SEAL;
513 sign_usage = KG_USAGE_ACCEPTOR_SIGN;
514 seal_usage = KG_USAGE_ACCEPTOR_SEAL;
518 * These are from rfc4142, but I don't understand: if we supply
519 * different 'usage' value for client & server, then the peers
520 * will have different derived keys. How could this work?
522 * Here we simply use old SIGN/SEAL values until we find the
526 sign_usage = KG_USAGE_SIGN;
527 seal_usage = KG_USAGE_SEAL;
530 /* derive and send down: Ke, Ki, and Kc */
533 if (derive_key_lucid(keyptr, &derived_key,
534 seal_usage, KEY_USAGE_SEED_ENCRYPTION))
536 if (write_bytes(&p, end, derived_key.data,
539 free(derived_key.data);
542 if (derive_key_lucid(keyptr, &derived_key,
543 seal_usage, KEY_USAGE_SEED_INTEGRITY))
545 if (write_bytes(&p, end, derived_key.data,
548 free(derived_key.data);
551 if (derive_key_lucid(keyptr, &derived_key,
552 sign_usage, KEY_USAGE_SEED_CHECKSUM))
554 if (write_bytes(&p, end, derived_key.data,
557 free(derived_key.data);
560 buf->length = p - (char *)buf->value;
564 printerr(0, "ERROR: %s: failed serializing krb5 context for kernel\n",
578 serialize_krb5_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf)
580 OM_uint32 maj_stat, min_stat;
581 void *return_ctx = 0;
583 gss_krb5_lucid_context_v1_t *lctx = 0;
586 printerr(3, "lucid version!\n");
587 maj_stat = gss_export_lucid_sec_context(&min_stat, &ctx,
589 if (maj_stat != GSS_S_COMPLETE) {
590 pgsserr("gss_export_lucid_sec_context",
591 maj_stat, min_stat, &krb5oid);
595 /* Check the version returned, we only support v1 right now */
596 vers = ((gss_krb5_lucid_context_version_t *)return_ctx)->version;
599 lctx = (gss_krb5_lucid_context_v1_t *) return_ctx;
602 printerr(0, "ERROR: unsupported lucid sec context version %d\n",
609 * Now lctx points to a lucid context that we can send down to kernel
611 * Note: we send down different information to the kernel depending
612 * on the protocol version and the enctyption type.
613 * For protocol version 0 with all enctypes besides DES3, we use
614 * the original format. For protocol version != 0 or DES3, we
615 * send down the new style information.
618 if (lctx->protocol == 0 && lctx->rfc1964_kd.ctx_key.type <= 4)
619 retcode = prepare_krb5_rfc1964_buffer(lctx, buf);
621 retcode = prepare_krb5_rfc4121_buffer(lctx, buf);
623 maj_stat = gss_free_lucid_sec_context(&min_stat, ctx, return_ctx);
624 if (maj_stat != GSS_S_COMPLETE) {
625 pgsserr("gss_export_lucid_sec_context",
626 maj_stat, min_stat, &krb5oid);
627 printerr(0, "WARN: failed to free lucid sec context\n");
631 printerr(1, "%s: prepare_krb5_*_buffer failed (retcode = %d)\n",
632 __FUNCTION__, retcode);
639 printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
645 #endif /* HAVE_LUCID_CONTEXT_SUPPORT */