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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];
89 uint32_t word_send_seq;
90 gss_krb5_lucid_key_t enc_key;
93 gss_buffer_desc fakeoid;
96 * The new Kerberos interface to get the gss context
97 * does not include the seed or seed_init fields
98 * because we never really use them. But for now,
99 * send down a fake buffer so we can use the same
100 * interface to the kernel.
102 memset(&enc_key, 0, sizeof(enc_key));
103 memset(&fakeoid, 0, sizeof(fakeoid));
105 if (!(buf->value = calloc(1, MAX_CTX_LEN)))
108 end = buf->value + MAX_CTX_LEN;
110 if (WRITE_BYTES(&p, end, lctx->initiate)) goto out_err;
112 /* seed_init and seed not used by kernel anyway */
113 if (WRITE_BYTES(&p, end, constant_zero)) goto out_err;
114 if (write_bytes(&p, end, &fakeseed, 16)) goto out_err;
116 if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.sign_alg)) goto out_err;
117 if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.seal_alg)) goto out_err;
118 if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
119 word_send_seq = lctx->send_seq; /* XXX send_seq is 64-bit */
120 if (WRITE_BYTES(&p, end, word_send_seq)) goto out_err;
121 if (write_oid(&p, end, &krb5oid)) goto out_err;
125 * The kernel gss code expects des-cbc-raw for all flavors of des.
126 * The keytype from MIT has this type, but Heimdal does not.
127 * Force the Heimdal keytype to 4 (des-cbc-raw).
128 * Note that the rfc1964 version only supports DES enctypes.
130 if (lctx->rfc1964_kd.ctx_key.type != 4) {
131 printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
132 __FUNCTION__, lctx->rfc1964_kd.ctx_key.type, 4);
133 lctx->rfc1964_kd.ctx_key.type = 4;
136 printerr(2, "%s: serializing keys with enctype %d and length %d\n",
137 __FUNCTION__, lctx->rfc1964_kd.ctx_key.type,
138 lctx->rfc1964_kd.ctx_key.length);
140 /* derive the encryption key and copy it into buffer */
141 enc_key.type = lctx->rfc1964_kd.ctx_key.type;
142 enc_key.length = lctx->rfc1964_kd.ctx_key.length;
143 if ((enc_key.data = calloc(1, enc_key.length)) == NULL)
145 skd = (char *) lctx->rfc1964_kd.ctx_key.data;
146 dkd = (char *) enc_key.data;
147 for (i = 0; i < enc_key.length; i++)
148 dkd[i] = skd[i] ^ 0xf0;
149 if (write_lucid_keyblock(&p, end, &enc_key)) {
155 if (write_lucid_keyblock(&p, end, &lctx->rfc1964_kd.ctx_key))
158 buf->length = p - (char *)buf->value;
161 printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
162 if (buf->value) free(buf->value);
164 if (enc_key.data) free(enc_key.data);
168 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
169 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
172 #define KG_USAGE_SEAL 22
173 #define KG_USAGE_SIGN 23
174 #define KG_USAGE_SEQ 24
177 #define KG_USAGE_ACCEPTOR_SEAL 22
178 #define KG_USAGE_ACCEPTOR_SIGN 23
179 #define KG_USAGE_INITIATOR_SEAL 24
180 #define KG_USAGE_INITIATOR_SIGN 25
182 /* Lifted from mit src/lib/gssapi/krb5/gssapiP_krb5.h */
184 SEAL_ALG_NONE = 0xffff,
185 SEAL_ALG_DES = 0x0000,
186 SEAL_ALG_1 = 0x0001, /* not published */
187 SEAL_ALG_MICROSOFT_RC4 = 0x0010, /* microsoft w2k; */
188 SEAL_ALG_DES3KD = 0x0002
191 #define KEY_USAGE_SEED_ENCRYPTION 0xAA
192 #define KEY_USAGE_SEED_INTEGRITY 0x55
193 #define KEY_USAGE_SEED_CHECKSUM 0x99
196 /* Flags for version 2 context flags */
197 #define KRB5_CTX_FLAG_INITIATOR 0x00000001
198 #define KRB5_CTX_FLAG_CFX 0x00000002
199 #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
201 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
202 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
204 * We don't have "legal" access to these MIT-only
205 * structures located in libk5crypto
207 extern void krb5int_enc_arcfour;
208 extern void krb5int_enc_des3;
209 extern void krb5int_enc_aes128;
210 extern void krb5int_enc_aes256;
211 extern int krb5_derive_key();
214 key_lucid_to_krb5(const gss_krb5_lucid_key_t *lin, krb5_keyblock *kout)
216 memset(kout, '\0', sizeof(kout));
218 kout->enctype = lin->type;
219 kout->length = lin->length;
220 kout->contents = lin->data;
222 kout->keytype = lin->type;
223 kout->keyvalue.length = lin->length;
224 kout->keyvalue.data = lin->data;
229 key_krb5_to_lucid(const krb5_keyblock *kin, gss_krb5_lucid_key_t *lout)
231 memset(lout, '\0', sizeof(lout));
233 lout->type = kin->enctype;
234 lout->length = kin->length;
235 lout->data = kin->contents;
237 lout->type = kin->keytype;
238 lout->length = kin->keyvalue.length;
239 memcpy(lout->data, kin->keyvalue.data, kin->keyvalue.length);
243 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
244 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
245 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
246 /* XXX Hack alert! XXX Do NOT submit upstream! XXX */
248 * Function to derive a new key from a given key and given constant data.
250 static krb5_error_code
251 derive_key_lucid(const gss_krb5_lucid_key_t *in, gss_krb5_lucid_key_t *out,
252 int usage, char extra)
254 krb5_error_code code;
255 unsigned char constant_data[K5CLENGTH];
259 krb5_keyblock kin, kout; /* must send krb5_keyblock, not lucid! */
261 krb5_context kcontext;
262 krb5_keyblock *outkey;
266 * XXX Hack alert. We don't have "legal" access to these
267 * values and structures located in libk5crypto
270 case ENCTYPE_DES3_CBC_SHA1:
272 case ENCTYPE_DES3_CBC_RAW:
276 enc = &krb5int_enc_des3;
279 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
282 enc = &krb5int_enc_aes128;
285 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
288 enc = &krb5int_enc_aes256;
292 code = KRB5_BAD_ENCTYPE;
296 /* allocate memory for output key */
297 if ((out->data = malloc(keylength)) == NULL) {
301 out->length = keylength;
302 out->type = in->type;
304 /* Convert to correct format for call to krb5_derive_key */
305 key_lucid_to_krb5(in, &kin);
306 key_lucid_to_krb5(out, &kout);
308 datain.data = (char *) constant_data;
309 datain.length = K5CLENGTH;
311 ((char *)(datain.data))[0] = (usage>>24)&0xff;
312 ((char *)(datain.data))[1] = (usage>>16)&0xff;
313 ((char *)(datain.data))[2] = (usage>>8)&0xff;
314 ((char *)(datain.data))[3] = usage&0xff;
316 ((char *)(datain.data))[4] = (char) extra;
319 code = krb5_derive_key(enc, &kin, &kout, &datain);
321 if ((code = krb5_init_context(&kcontext))) {
323 code = krb5_derive_key(kcontext, &kin, in->type, constant_data, K5CLENGTH, &outkey);
331 key_krb5_to_lucid(&kout, out);
333 key_krb5_to_lucid(outkey, out);
334 krb5_free_keyblock(kcontext, outkey);
335 krb5_free_context(kcontext);
340 printerr(0, "ERROR: %s: returning error %d (%s)\n",
341 __FUNCTION__, code, error_message(code));
347 * Prepare a new-style buffer, as defined in rfc4121 (a.k.a. cfx),
348 * to send to the kernel for newer encryption types -- or for DES3.
352 * u32 initiate; ( whether we are the initiator or not )
355 * #define KRB5_CTX_FLAG_INITIATOR 0x00000001
356 * #define KRB5_CTX_FLAG_CFX 0x00000002
357 * #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
359 * u32 enctype; ( encrption type of keys )
360 * u32 size_of_each_key; ( size of each key in bytes )
361 * u32 number_of_keys; ( N -- should always be 3 for now )
368 prepare_krb5_rfc4121_buffer(gss_krb5_lucid_context_v1_t *lctx,
369 gss_buffer_desc *buf)
371 static int constant_two = 2;
373 uint32_t v2_flags = 0;
374 gss_krb5_lucid_key_t enc_key;
375 gss_krb5_lucid_key_t derived_key;
376 gss_buffer_desc fakeoid;
381 memset(&enc_key, 0, sizeof(enc_key));
382 memset(&fakeoid, 0, sizeof(fakeoid));
384 if (!(buf->value = calloc(1, MAX_CTX_LEN)))
387 end = buf->value + MAX_CTX_LEN;
390 if (WRITE_BYTES(&p, end, constant_two)) goto out_err;
391 if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
394 v2_flags |= KRB5_CTX_FLAG_INITIATOR;
395 if (lctx->protocol != 0)
396 v2_flags |= KRB5_CTX_FLAG_CFX;
397 if (lctx->protocol != 0 && lctx->cfx_kd.have_acceptor_subkey == 1)
398 v2_flags |= KRB5_CTX_FLAG_ACCEPTOR_SUBKEY;
400 if (WRITE_BYTES(&p, end, v2_flags)) goto out_err;
402 if (WRITE_BYTES(&p, end, lctx->send_seq)) goto out_err;
404 /* Protocol 0 here implies DES3 or RC4 */
405 printerr(3, "protocol %d\n", lctx->protocol);
406 if (lctx->protocol == 0) {
407 enctype = lctx->rfc1964_kd.ctx_key.type;
410 * The kernel gss code expects ENCTYPE_DES3_CBC_RAW (6) for
411 * 3des keys, but Heimdal key has ENCTYPE_DES3_CBC_SHA1 (16).
412 * Force the Heimdal enctype to 6.
414 if (enctype == ENCTYPE_DES3_CBC_SHA1) {
415 printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
416 __FUNCTION__, enctype, 6);
421 keysize = lctx->rfc1964_kd.ctx_key.length;
422 numkeys = 3; /* XXX is always gonna be three? */
424 if (lctx->cfx_kd.have_acceptor_subkey) {
425 enctype = lctx->cfx_kd.acceptor_subkey.type;
426 keysize = lctx->cfx_kd.acceptor_subkey.length;
428 enctype = lctx->cfx_kd.ctx_key.type;
429 keysize = lctx->cfx_kd.ctx_key.length;
433 printerr(3, "serializing %d keys with enctype %d and size %d\n",
434 numkeys, enctype, keysize);
435 if (WRITE_BYTES(&p, end, enctype)) goto out_err;
436 if (WRITE_BYTES(&p, end, keysize)) goto out_err;
437 if (WRITE_BYTES(&p, end, numkeys)) goto out_err;
439 if (lctx->protocol == 0) {
440 /* derive and send down: Ke, Ki, and Kc */
442 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
443 lctx->rfc1964_kd.ctx_key.length))
447 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
448 lctx->rfc1964_kd.ctx_key.length))
453 * RC4 is special, it dosen't need key derivation. Actually
454 * the Ke is based on plain text. Here we just let all three
455 * key identical, kernel will handle everything. --ericm
457 if (lctx->rfc1964_kd.ctx_key.type == ENCTYPE_ARCFOUR_HMAC) {
458 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
459 lctx->rfc1964_kd.ctx_key.length))
462 if (derive_key_lucid(&lctx->rfc1964_kd.ctx_key,
464 KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM))
466 if (write_bytes(&p, end, derived_key.data,
469 free(derived_key.data);
472 gss_krb5_lucid_key_t *keyptr;
473 uint32_t sign_usage, seal_usage;
475 if (lctx->cfx_kd.have_acceptor_subkey)
476 keyptr = &lctx->cfx_kd.acceptor_subkey;
478 keyptr = &lctx->cfx_kd.ctx_key;
481 if (lctx->initiate == 1) {
482 sign_usage = KG_USAGE_INITIATOR_SIGN;
483 seal_usage = KG_USAGE_INITIATOR_SEAL;
485 sign_usage = KG_USAGE_ACCEPTOR_SIGN;
486 seal_usage = KG_USAGE_ACCEPTOR_SEAL;
490 * These are from rfc4142, but I don't understand: if we supply
491 * different 'usage' value for client & server, then the peers
492 * will have different derived keys. How could this work?
494 * Here we simply use old SIGN/SEAL values until we find the
498 sign_usage = KG_USAGE_SIGN;
499 seal_usage = KG_USAGE_SEAL;
502 /* derive and send down: Ke, Ki, and Kc */
505 if (derive_key_lucid(keyptr, &derived_key,
506 seal_usage, KEY_USAGE_SEED_ENCRYPTION))
508 if (write_bytes(&p, end, derived_key.data,
511 free(derived_key.data);
514 if (derive_key_lucid(keyptr, &derived_key,
515 seal_usage, KEY_USAGE_SEED_INTEGRITY))
517 if (write_bytes(&p, end, derived_key.data,
520 free(derived_key.data);
523 if (derive_key_lucid(keyptr, &derived_key,
524 sign_usage, KEY_USAGE_SEED_CHECKSUM))
526 if (write_bytes(&p, end, derived_key.data,
529 free(derived_key.data);
532 buf->length = p - (char *)buf->value;
536 printerr(0, "ERROR: %s: failed serializing krb5 context for kernel\n",
550 serialize_krb5_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf)
552 OM_uint32 maj_stat, min_stat;
553 void *return_ctx = 0;
555 gss_krb5_lucid_context_v1_t *lctx = 0;
558 printerr(3, "lucid version!\n");
559 maj_stat = gss_export_lucid_sec_context(&min_stat, &ctx,
561 if (maj_stat != GSS_S_COMPLETE) {
562 pgsserr("gss_export_lucid_sec_context",
563 maj_stat, min_stat, &krb5oid);
567 /* Check the version returned, we only support v1 right now */
568 vers = ((gss_krb5_lucid_context_version_t *)return_ctx)->version;
571 lctx = (gss_krb5_lucid_context_v1_t *) return_ctx;
574 printerr(0, "ERROR: unsupported lucid sec context version %d\n",
581 * Now lctx points to a lucid context that we can send down to kernel
583 * Note: we send down different information to the kernel depending
584 * on the protocol version and the enctyption type.
585 * For protocol version 0 with all enctypes besides DES3, we use
586 * the original format. For protocol version != 0 or DES3, we
587 * send down the new style information.
590 if (lctx->protocol == 0 && lctx->rfc1964_kd.ctx_key.type <= 4)
591 retcode = prepare_krb5_rfc1964_buffer(lctx, buf);
593 retcode = prepare_krb5_rfc4121_buffer(lctx, buf);
595 maj_stat = gss_free_lucid_sec_context(&min_stat, ctx, return_ctx);
596 if (maj_stat != GSS_S_COMPLETE) {
597 pgsserr("gss_export_lucid_sec_context",
598 maj_stat, min_stat, &krb5oid);
599 printerr(0, "WARN: failed to free lucid sec context\n");
603 printerr(1, "%s: prepare_krb5_*_buffer failed (retcode = %d)\n",
604 __FUNCTION__, retcode);
611 printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
617 #endif /* HAVE_LUCID_CONTEXT_SUPPORT */