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, 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 key->keyvalue.data, key->keyvalue.length,
107 rep->hash->length = HMAC_size(&ctx);
108 rep->hash->data = malloc(rep->hash->length);
109 if (rep->hash->data == NULL) {
110 HMAC_CTX_cleanup(&ctx);
111 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
115 HMAC_Update(&ctx, version_2_0, sizeof(version_2_0));
116 if (rep->error_code) {
117 int32_t t = *rep->error_code;
119 unsigned char p = (t & 0xff);
120 HMAC_Update(&ctx, &p, 1);
124 if (rep->certificate)
125 HMAC_Update(&ctx, rep->certificate->data, rep->certificate->length);
127 HMAC_Update(&ctx, (unsigned char *)*rep->e_text, strlen(*rep->e_text));
129 HMAC_Final(&ctx, rep->hash->data, 0);
130 HMAC_CTX_cleanup(&ctx);
136 * Build a certifate for `principal´ that will expire at `endtime´.
139 static krb5_error_code
140 build_certificate(krb5_context context,
141 krb5_kdc_configuration *config,
142 const krb5_data *key,
144 krb5_principal principal,
145 krb5_data *certificate)
147 hx509_context hxctx = NULL;
148 hx509_ca_tbs tbs = NULL;
149 hx509_env env = NULL;
150 hx509_cert cert = NULL;
151 hx509_cert signer = NULL;
154 if (krb5_principal_get_comp_string(context, principal, 1) != NULL) {
155 kdc_log(context, config, 0, "Principal is not a user");
159 ret = hx509_context_init(&hxctx);
163 ret = hx509_env_add(hxctx, &env, "principal-name",
164 krb5_principal_get_comp_string(context, principal, 0));
172 ret = hx509_certs_init(hxctx, config->kx509_ca, 0,
175 kdc_log(context, config, 0, "Failed to load CA %s",
179 ret = hx509_query_alloc(hxctx, &q);
181 hx509_certs_free(&certs);
185 hx509_query_match_option(q, HX509_QUERY_OPTION_PRIVATE_KEY);
186 hx509_query_match_option(q, HX509_QUERY_OPTION_KU_KEYCERTSIGN);
188 ret = hx509_certs_find(hxctx, certs, q, &signer);
189 hx509_query_free(hxctx, q);
190 hx509_certs_free(&certs);
192 kdc_log(context, config, 0, "Failed to find a CA in %s",
198 ret = hx509_ca_tbs_init(hxctx, &tbs);
203 SubjectPublicKeyInfo spki;
206 memset(&spki, 0, sizeof(spki));
208 spki.subjectPublicKey.data = key->data;
209 spki.subjectPublicKey.length = key->length * 8;
211 ret = der_copy_oid(oid_id_pkcs1_rsaEncryption(),
212 &spki.algorithm.algorithm);
214 any.data = "\x05\x00";
216 spki.algorithm.parameters = &any;
218 ret = hx509_ca_tbs_set_spki(hxctx, tbs, &spki);
219 der_free_oid(&spki.algorithm.algorithm);
228 ret = hx509_certs_init(hxctx, config->kx509_template, 0,
231 kdc_log(context, config, 0, "Failed to load template %s",
232 config->kx509_template);
235 ret = hx509_get_one_cert(hxctx, certs, &template);
236 hx509_certs_free(&certs);
238 kdc_log(context, config, 0, "Failed to find template in %s",
239 config->kx509_template);
242 ret = hx509_ca_tbs_set_template(hxctx, tbs,
243 HX509_CA_TEMPLATE_SUBJECT|
244 HX509_CA_TEMPLATE_KU|
245 HX509_CA_TEMPLATE_EKU,
247 hx509_cert_free(template);
252 hx509_ca_tbs_set_notAfter(hxctx, tbs, endtime);
254 hx509_ca_tbs_subject_expand(hxctx, tbs, env);
255 hx509_env_free(&env);
257 ret = hx509_ca_sign(hxctx, tbs, signer, &cert);
258 hx509_cert_free(signer);
262 hx509_ca_tbs_free(&tbs);
264 ret = hx509_cert_binary(hxctx, cert, certificate);
265 hx509_cert_free(cert);
269 hx509_context_free(&hxctx);
274 hx509_env_free(&env);
276 hx509_ca_tbs_free(&tbs);
278 hx509_cert_free(signer);
280 hx509_context_free(&hxctx);
281 krb5_set_error_message(context, ret, "cert creation failed");
290 _kdc_do_kx509(krb5_context context,
291 krb5_kdc_configuration *config,
292 const Kx509Request *req, krb5_data *reply,
293 const char *from, struct sockaddr *addr)
296 krb5_ticket *ticket = NULL;
297 krb5_flags ap_req_options;
298 krb5_auth_context ac = NULL;
299 krb5_keytab id = NULL;
300 krb5_principal sprincipal = NULL, cprincipal = NULL;
304 krb5_keyblock *key = NULL;
306 krb5_data_zero(reply);
307 memset(&rep, 0, sizeof(rep));
309 if(!config->enable_kx509) {
310 kdc_log(context, config, 0,
311 "Rejected kx509 request (disabled) from %s", from);
312 return KRB5KDC_ERR_POLICY;
315 kdc_log(context, config, 0, "Kx509 request from %s", from);
317 ret = krb5_kt_resolve(context, "HDB:", &id);
319 kdc_log(context, config, 0, "Can't open database for digest");
323 ret = krb5_rd_req(context,
333 ret = krb5_ticket_get_client(context, ticket, &cprincipal);
337 ret = krb5_unparse_name(context, cprincipal, &cname);
341 /* verify server principal */
343 ret = krb5_sname_to_principal(context, NULL, "kca_service",
344 KRB5_NT_UNKNOWN, &sprincipal);
349 krb5_principal principal = NULL;
351 ret = krb5_ticket_get_server(context, ticket, &principal);
355 ret = krb5_principal_compare(context, sprincipal, principal);
356 krb5_free_principal(context, principal);
358 ret = KRB5KDC_ERR_SERVER_NOMATCH;
359 krb5_set_error_message(context, ret,
360 "User %s used wrong Kx509 service principal",
366 ret = krb5_auth_con_getkey(context, ac, &key);
367 if (ret == 0 && key == NULL)
368 ret = KRB5KDC_ERR_NULL_KEY;
370 krb5_set_error_message(context, ret, "Kx509 can't get session key");
374 ret = verify_req_hash(context, req, key);
378 /* Verify that the key is encoded RSA key */
383 ret = decode_RSAPublicKey(req->pk_key.data, req->pk_key.length,
387 free_RSAPublicKey(&key);
388 if (size != req->pk_key.length)
392 ALLOC(rep.certificate);
393 if (rep.certificate == NULL)
395 krb5_data_zero(rep.certificate);
397 if (rep.hash == NULL)
399 krb5_data_zero(rep.hash);
401 ret = build_certificate(context, config, &req->pk_key,
402 krb5_ticket_get_endtime(context, ticket),
403 cprincipal, rep.certificate);
407 ret = calculate_reply_hash(context, key, &rep);
412 * Encode reply, [ version | Kx509Response ]
418 ASN1_MALLOC_ENCODE(Kx509Response, data.data, data.length, &rep,
421 krb5_set_error_message(context, ret, "Failed to encode kx509 reply");
424 if (size != data.length)
425 krb5_abortx(context, "ASN1 internal error");
427 ret = krb5_data_alloc(reply, data.length + sizeof(version_2_0));
432 memcpy(reply->data, version_2_0, sizeof(version_2_0));
433 memcpy(((unsigned char *)reply->data) + sizeof(version_2_0),
434 data.data, data.length);
438 kdc_log(context, config, 0, "Successful Kx509 request for %s", cname);
442 krb5_auth_con_free(context, ac);
444 krb5_warn(context, ret, "Kx509 request from %s failed", from);
446 krb5_free_ticket(context, ticket);
448 krb5_kt_close(context, id);
450 krb5_free_principal(context, sprincipal);
452 krb5_free_principal(context, cprincipal);
454 krb5_free_keyblock (context, key);
457 free_Kx509Response(&rep);