2 * Copyright (c) 2006 - 2007 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
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7 * modification, are permitted provided that the following conditions
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36 #include <rfc2459_asn1.h>
46 _kdc_try_kx509_request(void *ptr, size_t len, struct Kx509Request *req, size_t *size)
50 if (memcmp("\x00\x00\x02\x00", ptr, 4) != 0)
52 return decode_Kx509Request(((unsigned char *)ptr) + 4, len - 4, req, size);
59 static const unsigned char version_2_0[4] = {0 , 0, 2, 0};
61 static krb5_error_code
62 verify_req_hash(krb5_context context,
63 const Kx509Request *req,
66 unsigned char digest[SHA_DIGEST_LENGTH];
69 if (req->pk_hash.length != sizeof(digest)) {
70 krb5_set_error_message(context, KRB5KDC_ERR_PREAUTH_FAILED,
71 "pk-hash have wrong length: %lu",
72 (unsigned long)req->pk_hash.length);
73 return KRB5KDC_ERR_PREAUTH_FAILED;
78 key->keyvalue.data, key->keyvalue.length,
80 if (sizeof(digest) != HMAC_size(&ctx))
81 krb5_abortx(context, "runtime error, hmac buffer wrong size in kx509");
82 HMAC_Update(&ctx, version_2_0, sizeof(version_2_0));
83 HMAC_Update(&ctx, req->pk_key.data, req->pk_key.length);
84 HMAC_Final(&ctx, digest, 0);
85 HMAC_CTX_cleanup(&ctx);
87 if (memcmp(req->pk_hash.data, digest, sizeof(digest)) != 0) {
88 krb5_set_error_message(context, KRB5KDC_ERR_PREAUTH_FAILED,
89 "pk-hash is not correct");
90 return KRB5KDC_ERR_PREAUTH_FAILED;
95 static krb5_error_code
96 calculate_reply_hash(krb5_context context,
105 HMAC_Init_ex(&ctx, key->keyvalue.data, key->keyvalue.length,
107 ret = krb5_data_alloc(rep->hash, HMAC_size(&ctx));
109 HMAC_CTX_cleanup(&ctx);
110 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
114 HMAC_Update(&ctx, version_2_0, sizeof(version_2_0));
115 if (rep->error_code) {
116 int32_t t = *rep->error_code;
118 unsigned char p = (t & 0xff);
119 HMAC_Update(&ctx, &p, 1);
123 if (rep->certificate)
124 HMAC_Update(&ctx, rep->certificate->data, rep->certificate->length);
126 HMAC_Update(&ctx, (unsigned char *)*rep->e_text, strlen(*rep->e_text));
128 HMAC_Final(&ctx, rep->hash->data, 0);
129 HMAC_CTX_cleanup(&ctx);
135 * Build a certifate for `principal´ that will expire at `endtime´.
138 static krb5_error_code
139 build_certificate(krb5_context context,
140 krb5_kdc_configuration *config,
141 const krb5_data *key,
143 krb5_principal principal,
144 krb5_data *certificate)
147 const char *kx509_ca;
148 hx509_ca_tbs tbs = NULL;
149 hx509_env env = NULL;
150 hx509_cert cert = NULL;
151 hx509_cert signer = NULL;
152 krb5_boolean def_bool;
155 ret = krb5_unparse_name_flags(context, principal,
156 KRB5_PRINCIPAL_UNPARSE_NO_REALM,
161 ret = hx509_env_add(context->hx509ctx, &env, "principal-name-without-realm",
169 * Include the realm in the principal-name env var; the template
170 * might not use $principal-name-realm after all.
172 ret = krb5_unparse_name(context, principal, &name);
176 ret = hx509_env_add(context->hx509ctx, &env, "principal-name",
181 ret = hx509_env_add(context->hx509ctx, &env, "principal-name-realm",
182 krb5_principal_get_realm(context, principal));
186 /* Pick an issuer based on the crealm if we can */
187 kx509_ca = krb5_config_get_string(context, NULL, "kdc",
188 krb5_principal_get_realm(context,
191 if (kx509_ca == NULL)
192 kx509_ca = config->kx509_ca;
198 ret = hx509_certs_init(context->hx509ctx, config->kx509_ca, 0,
201 kdc_log(context, config, 0, "Failed to load CA %s",
205 ret = hx509_query_alloc(context->hx509ctx, &q);
207 hx509_certs_free(&certs);
211 hx509_query_match_option(q, HX509_QUERY_OPTION_PRIVATE_KEY);
212 hx509_query_match_option(q, HX509_QUERY_OPTION_KU_KEYCERTSIGN);
214 ret = hx509_certs_find(context->hx509ctx, certs, q, &signer);
215 hx509_query_free(context->hx509ctx, q);
216 hx509_certs_free(&certs);
218 kdc_log(context, config, 0, "Failed to find a CA in %s",
224 ret = hx509_ca_tbs_init(context->hx509ctx, &tbs);
229 SubjectPublicKeyInfo spki;
232 memset(&spki, 0, sizeof(spki));
234 spki.subjectPublicKey.data = key->data;
235 spki.subjectPublicKey.length = key->length * 8;
237 ret = der_copy_oid(&asn1_oid_id_pkcs1_rsaEncryption,
238 &spki.algorithm.algorithm);
240 any.data = "\x05\x00";
242 spki.algorithm.parameters = &any;
244 ret = hx509_ca_tbs_set_spki(context->hx509ctx, tbs, &spki);
245 der_free_oid(&spki.algorithm.algorithm);
254 ret = hx509_certs_init(context->hx509ctx, config->kx509_template, 0,
257 kdc_log(context, config, 0, "Failed to load template %s",
258 config->kx509_template);
261 ret = hx509_get_one_cert(context->hx509ctx, certs, &template);
262 hx509_certs_free(&certs);
264 kdc_log(context, config, 0, "Failed to find template in %s",
265 config->kx509_template);
268 ret = hx509_ca_tbs_set_template(context->hx509ctx, tbs,
269 HX509_CA_TEMPLATE_SUBJECT|
270 HX509_CA_TEMPLATE_KU|
271 HX509_CA_TEMPLATE_EKU,
273 hx509_cert_free(template);
278 def_bool = krb5_config_get_bool_default(context, NULL, TRUE, "kdc",
279 "kx509_include_pkinit_san",
281 if (krb5_config_get_bool_default(context, NULL, def_bool, "kdc",
282 krb5_principal_get_realm(context,
284 "kx509_include_pkinit_san",
286 ret = hx509_ca_tbs_add_san_pkinit(context->hx509ctx, tbs, name);
291 hx509_ca_tbs_set_notAfter(context->hx509ctx, tbs, endtime);
293 hx509_ca_tbs_subject_expand(context->hx509ctx, tbs, env);
294 hx509_env_free(&env);
296 ret = hx509_ca_sign(context->hx509ctx, tbs, signer, &cert);
297 hx509_cert_free(signer);
301 hx509_ca_tbs_free(&tbs);
303 ret = hx509_cert_binary(context->hx509ctx, cert, certificate);
304 hx509_cert_free(cert);
308 /* cleanup on success */
316 hx509_env_free(&env);
318 hx509_ca_tbs_free(&tbs);
320 hx509_cert_free(signer);
321 krb5_set_error_message(context, ret, "cert creation failed");
330 _kdc_do_kx509(krb5_context context,
331 krb5_kdc_configuration *config,
332 const struct Kx509Request *req, krb5_data *reply,
333 const char *from, struct sockaddr *addr)
336 krb5_ticket *ticket = NULL;
337 krb5_flags ap_req_options;
338 krb5_auth_context ac = NULL;
339 krb5_keytab id = NULL;
340 krb5_principal sprincipal = NULL, cprincipal = NULL;
344 krb5_keyblock *key = NULL;
345 krb5_boolean def_bool;
347 krb5_data_zero(reply);
348 memset(&rep, 0, sizeof(rep));
350 if(!config->enable_kx509) {
351 kdc_log(context, config, 0,
352 "Rejected kx509 request (disabled) from %s", from);
353 return KRB5KDC_ERR_POLICY;
356 kdc_log(context, config, 0, "Kx509 request from %s", from);
358 ret = krb5_kt_resolve(context, "HDBGET:", &id);
360 kdc_log(context, config, 0, "Can't open database for digest");
364 ret = krb5_rd_req(context,
374 ret = krb5_ticket_get_client(context, ticket, &cprincipal);
378 def_bool = krb5_config_get_bool_default(context, NULL, TRUE, "kdc",
379 "require_initial_kca_tickets",
381 if (!ticket->ticket.flags.initial &&
382 krb5_config_get_bool_default(context, NULL, def_bool, "kdc",
383 krb5_principal_get_realm(context,
385 "require_initial_kca_tickets", NULL)) {
386 ret = KRB5KDC_ERR_POLICY;
390 ret = krb5_unparse_name(context, cprincipal, &cname);
394 /* verify server principal */
396 ret = krb5_sname_to_principal(context, NULL, "kca_service",
397 KRB5_NT_UNKNOWN, &sprincipal);
402 krb5_principal principal = NULL;
404 ret = krb5_ticket_get_server(context, ticket, &principal);
408 ret = krb5_principal_compare(context, sprincipal, principal);
409 krb5_free_principal(context, principal);
411 char *expected, *used;
413 ret = krb5_unparse_name(context, sprincipal, &expected);
416 ret = krb5_unparse_name(context, principal, &used);
418 krb5_xfree(expected);
422 ret = KRB5KDC_ERR_SERVER_NOMATCH;
423 krb5_set_error_message(context, ret,
424 "User %s used wrong Kx509 service "
425 "principal, expected: %s, used %s",
426 cname, expected, used);
427 krb5_xfree(expected);
433 ret = krb5_auth_con_getkey(context, ac, &key);
434 if (ret == 0 && key == NULL)
435 ret = KRB5KDC_ERR_NULL_KEY;
437 krb5_set_error_message(context, ret, "Kx509 can't get session key");
441 ret = verify_req_hash(context, req, key);
445 /* Verify that the key is encoded RSA key */
447 RSAPublicKey rsapkey;
450 ret = decode_RSAPublicKey(req->pk_key.data, req->pk_key.length,
451 &rsapkey, &rsapkeysize);
454 free_RSAPublicKey(&rsapkey);
455 if (rsapkeysize != req->pk_key.length) {
456 ret = ASN1_EXTRA_DATA;
461 ALLOC(rep.certificate);
462 if (rep.certificate == NULL)
464 krb5_data_zero(rep.certificate);
466 if (rep.hash == NULL)
468 krb5_data_zero(rep.hash);
470 ret = build_certificate(context, config, &req->pk_key,
471 krb5_ticket_get_endtime(context, ticket),
472 cprincipal, rep.certificate);
476 ret = calculate_reply_hash(context, key, &rep);
481 * Encode reply, [ version | Kx509Response ]
487 ASN1_MALLOC_ENCODE(Kx509Response, data.data, data.length, &rep,
490 krb5_set_error_message(context, ret, "Failed to encode kx509 reply");
493 if (size != data.length)
494 krb5_abortx(context, "ASN1 internal error");
496 ret = krb5_data_alloc(reply, data.length + sizeof(version_2_0));
501 memcpy(reply->data, version_2_0, sizeof(version_2_0));
502 memcpy(((unsigned char *)reply->data) + sizeof(version_2_0),
503 data.data, data.length);
507 kdc_log(context, config, 0, "Successful Kx509 request for %s", cname);
511 krb5_auth_con_free(context, ac);
513 krb5_warn(context, ret, "Kx509 request from %s failed", from);
515 krb5_free_ticket(context, ticket);
517 krb5_kt_close(context, id);
519 krb5_free_principal(context, sprincipal);
521 krb5_free_principal(context, cprincipal);
523 krb5_free_keyblock (context, key);
526 free_Kx509Response(&rep);