return code;
}
+/*
+ simulate a kinit, putting the tgt in the given credentials cache.
+ Orignally by remus@snapserver.com
+
+ The impersonate_principal is the principal if NULL, or the principal to
+ impersonate
+
+ The self_service, should be the local service (for S4U2Self if
+ impersonate_principal is given).
+
+ The target_service defaults to the krbtgt if NULL, but could be
+ kpasswd/realm or a remote service (for S4U2Proxy)
+
+*/
+krb5_error_code kerberos_kinit_password_cc(krb5_context ctx,
+ krb5_ccache store_cc,
+ krb5_principal init_principal,
+ const char *init_password,
+ krb5_principal impersonate_principal,
+ const char *self_service,
+ const char *target_service,
+ krb5_get_init_creds_opt *krb_options,
+ time_t *expire_time,
+ time_t *kdc_time)
+{
+ krb5_error_code code = 0;
+ krb5_get_creds_opt options;
+ krb5_principal store_principal;
+ krb5_creds store_creds;
+ krb5_creds *s4u2self_creds;
+ Ticket s4u2self_ticket;
+ size_t s4u2self_ticketlen;
+ krb5_creds *s4u2proxy_creds;
+ krb5_principal self_princ;
+ bool s4u2proxy;
+ krb5_principal target_princ;
+ krb5_ccache tmp_cc;
+ const char *self_realm;
+ krb5_principal blacklist_principal = NULL;
+ krb5_principal whitelist_principal = NULL;
+
+ if (impersonate_principal && self_service == NULL) {
+ return EINVAL;
+ }
+
+ /*
+ * If we are not impersonating, then get this ticket for the
+ * target service, otherwise a krbtgt, and get the next ticket
+ * for the target
+ */
+ code = krb5_get_init_creds_password(ctx, &store_creds,
+ init_principal,
+ init_password,
+ NULL, NULL,
+ 0,
+ impersonate_principal ? NULL : target_service,
+ krb_options);
+ if (code != 0) {
+ return code;
+ }
+
+ store_principal = init_principal;
+
+ if (impersonate_principal == NULL) {
+ goto store;
+ }
+
+ /*
+ * We are trying S4U2Self now:
+ *
+ * As we do not want to expose our TGT in the
+ * krb5_ccache, which is also holds the impersonated creds.
+ *
+ * Some low level krb5/gssapi function might use the TGT
+ * identity and let the client act as our machine account.
+ *
+ * We need to avoid that and use a temporary krb5_ccache
+ * in order to pass our TGT to the krb5_get_creds() function.
+ */
+ code = krb5_cc_new_unique(ctx, NULL, NULL, &tmp_cc);
+ if (code != 0) {
+ krb5_free_cred_contents(ctx, &store_creds);
+ return code;
+ }
+
+ code = krb5_cc_initialize(ctx, tmp_cc, store_creds.client);
+ if (code != 0) {
+ krb5_cc_destroy(ctx, tmp_cc);
+ krb5_free_cred_contents(ctx, &store_creds);
+ return code;
+ }
+
+ code = krb5_cc_store_cred(ctx, tmp_cc, &store_creds);
+ if (code != 0) {
+ krb5_free_cred_contents(ctx, &store_creds);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ /*
+ * we need to remember the client principal of our
+ * TGT and make sure the KDC does not return this
+ * in the impersonated tickets. This can happen
+ * if the KDC does not support S4U2Self and S4U2Proxy.
+ */
+ blacklist_principal = store_creds.client;
+ store_creds.client = NULL;
+ krb5_free_cred_contents(ctx, &store_creds);
+
+ /*
+ * Check if we also need S4U2Proxy or if S4U2Self is
+ * enough in order to get a ticket for the target.
+ */
+ if (target_service == NULL) {
+ s4u2proxy = false;
+ } else if (strcmp(target_service, self_service) == 0) {
+ s4u2proxy = false;
+ } else {
+ s4u2proxy = true;
+ }
+
+ /*
+ * For S4U2Self we need our own service principal,
+ * which belongs to our own realm (available on
+ * our client principal).
+ */
+ self_realm = krb5_principal_get_realm(ctx, init_principal);
+
+ code = krb5_parse_name(ctx, self_service, &self_princ);
+ if (code != 0) {
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ code = krb5_principal_set_realm(ctx, self_princ, self_realm);
+ if (code != 0) {
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_free_principal(ctx, self_princ);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ code = krb5_get_creds_opt_alloc(ctx, &options);
+ if (code != 0) {
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_free_principal(ctx, self_princ);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ if (s4u2proxy) {
+ /*
+ * If we want S4U2Proxy, we need the forwardable flag
+ * on the S4U2Self ticket.
+ */
+ krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_FORWARDABLE);
+ }
+
+ code = krb5_get_creds_opt_set_impersonate(ctx, options,
+ impersonate_principal);
+ if (code != 0) {
+ krb5_get_creds_opt_free(ctx, options);
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_free_principal(ctx, self_princ);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ code = krb5_get_creds(ctx, options, tmp_cc,
+ self_princ, &s4u2self_creds);
+ krb5_get_creds_opt_free(ctx, options);
+ krb5_free_principal(ctx, self_princ);
+ if (code != 0) {
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ if (!s4u2proxy) {
+ krb5_cc_destroy(ctx, tmp_cc);
+
+ /*
+ * Now make sure we store the impersonated principal
+ * and creds instead of the TGT related stuff
+ * in the krb5_ccache of the caller.
+ */
+ code = krb5_copy_creds_contents(ctx, s4u2self_creds,
+ &store_creds);
+ krb5_free_creds(ctx, s4u2self_creds);
+ if (code != 0) {
+ return code;
+ }
+
+ /*
+ * It's important to store the principal the KDC
+ * returned, as otherwise the caller would not find
+ * the S4U2Self ticket in the krb5_ccache lookup.
+ */
+ store_principal = store_creds.client;
+ goto store;
+ }
+
+ /*
+ * We are trying S4U2Proxy:
+ *
+ * We need the ticket from the S4U2Self step
+ * and our TGT in order to get the delegated ticket.
+ */
+ code = decode_Ticket((const uint8_t *)s4u2self_creds->ticket.data,
+ s4u2self_creds->ticket.length,
+ &s4u2self_ticket,
+ &s4u2self_ticketlen);
+ if (code != 0) {
+ krb5_free_creds(ctx, s4u2self_creds);
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ /*
+ * we need to remember the client principal of the
+ * S4U2Self stage and as it needs to match the one we
+ * will get for the S4U2Proxy stage. We need this
+ * in order to detect KDCs which does not support S4U2Proxy.
+ */
+ whitelist_principal = s4u2self_creds->client;
+ s4u2self_creds->client = NULL;
+ krb5_free_creds(ctx, s4u2self_creds);
+
+ /*
+ * For S4U2Proxy we also got a target service principal,
+ * which also belongs to our own realm (available on
+ * our client principal).
+ */
+ code = krb5_parse_name(ctx, target_service, &target_princ);
+ if (code != 0) {
+ free_Ticket(&s4u2self_ticket);
+ krb5_free_principal(ctx, whitelist_principal);
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ code = krb5_principal_set_realm(ctx, target_princ, self_realm);
+ if (code != 0) {
+ free_Ticket(&s4u2self_ticket);
+ krb5_free_principal(ctx, target_princ);
+ krb5_free_principal(ctx, whitelist_principal);
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ code = krb5_get_creds_opt_alloc(ctx, &options);
+ if (code != 0) {
+ free_Ticket(&s4u2self_ticket);
+ krb5_free_principal(ctx, target_princ);
+ krb5_free_principal(ctx, whitelist_principal);
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_FORWARDABLE);
+ krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_CONSTRAINED_DELEGATION);
+
+ code = krb5_get_creds_opt_set_ticket(ctx, options, &s4u2self_ticket);
+ free_Ticket(&s4u2self_ticket);
+ if (code != 0) {
+ krb5_get_creds_opt_free(ctx, options);
+ krb5_free_principal(ctx, target_princ);
+ krb5_free_principal(ctx, whitelist_principal);
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_cc_destroy(ctx, tmp_cc);
+ return code;
+ }
+
+ code = krb5_get_creds(ctx, options, tmp_cc,
+ target_princ, &s4u2proxy_creds);
+ krb5_get_creds_opt_free(ctx, options);
+ krb5_free_principal(ctx, target_princ);
+ krb5_cc_destroy(ctx, tmp_cc);
+ if (code != 0) {
+ krb5_free_principal(ctx, whitelist_principal);
+ krb5_free_principal(ctx, blacklist_principal);
+ return code;
+ }
+
+ /*
+ * Now make sure we store the impersonated principal
+ * and creds instead of the TGT related stuff
+ * in the krb5_ccache of the caller.
+ */
+ code = krb5_copy_creds_contents(ctx, s4u2proxy_creds,
+ &store_creds);
+ krb5_free_creds(ctx, s4u2proxy_creds);
+ if (code != 0) {
+ krb5_free_principal(ctx, whitelist_principal);
+ krb5_free_principal(ctx, blacklist_principal);
+ return code;
+ }
+
+ /*
+ * It's important to store the principal the KDC
+ * returned, as otherwise the caller would not find
+ * the S4U2Self ticket in the krb5_ccache lookup.
+ */
+ store_principal = store_creds.client;
+
+ store:
+ if (blacklist_principal &&
+ krb5_principal_compare(ctx, store_creds.client, blacklist_principal)) {
+ char *sp = NULL;
+ char *ip = NULL;
+
+ code = krb5_unparse_name(ctx, blacklist_principal, &sp);
+ if (code != 0) {
+ sp = NULL;
+ }
+ code = krb5_unparse_name(ctx, impersonate_principal, &ip);
+ if (code != 0) {
+ ip = NULL;
+ }
+ DEBUG(1, ("kerberos_kinit_password_cc: "
+ "KDC returned self principal[%s] while impersonating [%s]\n",
+ sp?sp:"<no memory>",
+ ip?ip:"<no memory>"));
+
+ SAFE_FREE(sp);
+ SAFE_FREE(ip);
+
+ krb5_free_principal(ctx, whitelist_principal);
+ krb5_free_principal(ctx, blacklist_principal);
+ krb5_free_cred_contents(ctx, &store_creds);
+ return KRB5_FWD_BAD_PRINCIPAL;
+ }
+ if (blacklist_principal) {
+ krb5_free_principal(ctx, blacklist_principal);
+ }
+
+ if (whitelist_principal &&
+ !krb5_principal_compare(ctx, store_creds.client, whitelist_principal)) {
+ char *sp = NULL;
+ char *ep = NULL;
+
+ code = krb5_unparse_name(ctx, store_creds.client, &sp);
+ if (code != 0) {
+ sp = NULL;
+ }
+ code = krb5_unparse_name(ctx, whitelist_principal, &ep);
+ if (code != 0) {
+ ep = NULL;
+ }
+ DEBUG(1, ("kerberos_kinit_password_cc: "
+ "KDC returned wrong principal[%s] we expected [%s]\n",
+ sp?sp:"<no memory>",
+ ep?ep:"<no memory>"));
+
+ SAFE_FREE(sp);
+ SAFE_FREE(ep);
+
+ krb5_free_principal(ctx, whitelist_principal);
+ krb5_free_cred_contents(ctx, &store_creds);
+ return KRB5_FWD_BAD_PRINCIPAL;
+ }
+ if (whitelist_principal) {
+ krb5_free_principal(ctx, whitelist_principal);
+ }
+
+ code = krb5_cc_initialize(ctx, store_cc, store_principal);
+ if (code != 0) {
+ krb5_free_cred_contents(ctx, &store_creds);
+ return code;
+ }
+
+ code = krb5_cc_store_cred(ctx, store_cc, &store_creds);
+ if (code != 0) {
+ krb5_free_cred_contents(ctx, &store_creds);
+ return code;
+ }
+
+ if (expire_time) {
+ *expire_time = (time_t) store_creds.times.endtime;
+ }
+
+ if (kdc_time) {
+ *kdc_time = (time_t) store_creds.times.starttime;
+ }
+
+ krb5_free_cred_contents(ctx, &store_creds);
+
+ return 0;
+}
+
/*
* smb_krb5_principal_get_realm
*
git.samba.org / mat / samba.git / blobdiff