Catching more principals in ads_keytab_verify_ticket()
Michael Brown
mbrown at fensystems.co.uk
Sat Feb 26 13:42:00 GMT 2005
On Sat, 26 Feb 2005, Michael Brown wrote:
> My domain and realm are different, though it's only on a test network so
> this isn't a huge barrier. The major problem for me is the case
> variability; the method I'm proposing to fix this problem just happens
> to also makes it easy to cope with realm != domain.
>
> I'm working on a patch at the moment.
Patch against current SVN attached. Compiles cleanly with no warnings,
works when I test it.
Michael
-------------- next part --------------
Index: libads/kerberos_verify.c
===================================================================
--- libads/kerberos_verify.c (revision 5575)
+++ libads/kerberos_verify.c (working copy)
@@ -42,11 +42,11 @@
krb5_error_code ret = 0;
BOOL auth_ok = False;
krb5_keytab keytab = NULL;
+ krb5_kt_cursor cursor = NULL;
+ char *valid_princ_formats[7] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL };
+ char *host_princ_s = NULL;
fstring my_fqdn, my_name;
- fstring my_Fqdn, my_NAME;
- char *p_fqdn;
- char *host_princ_s[18];
- krb5_principal host_princ;
+ krb5_keytab_entry entry;
int i;
ret = krb5_kt_default(context, &keytab);
@@ -55,75 +55,74 @@
goto out;
}
- /* Generate the list of principal names which we expect clients might
- * want to use for authenticating to the file service. */
+ ret = krb5_kt_start_seq_get(context, keytab, &cursor);
+ if (ret) {
+ DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_start_seq_get failed (%s)\n", error_message(ret)));
+ goto out;
+ }
- fstrcpy(my_name, global_myname());
- strlower_m(my_name);
+ /* Generate the list of principal names which we expect
+ * clients might want to use for authenticating to the file
+ * service. We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
- fstrcpy(my_NAME, global_myname());
- strupper_m(my_NAME);
-
+ fstrcpy(my_name, global_myname());
my_fqdn[0] = '\0';
name_to_fqdn(my_fqdn, global_myname());
- strlower_m(my_fqdn);
- p_fqdn = strchr_m(my_fqdn, '.');
- fstrcpy(my_Fqdn, my_NAME);
- if (p_fqdn) {
- fstrcat(my_Fqdn, p_fqdn);
- }
+ asprintf(&valid_princ_formats[0], "%s$@%s", my_name, lp_realm());
+ asprintf(&valid_princ_formats[1], "host/%s@%s", my_name, lp_realm());
+ asprintf(&valid_princ_formats[2], "host/%s@%s", my_fqdn, lp_realm());
+ asprintf(&valid_princ_formats[3], "host/%s.%s@%s", my_name, lp_realm(), lp_realm());
+ asprintf(&valid_princ_formats[4], "cifs/%s@%s", my_name, lp_realm());
+ asprintf(&valid_princ_formats[5], "cifs/%s@%s", my_fqdn, lp_realm());
+ asprintf(&valid_princ_formats[6], "cifs/%s.%s@%s", my_name, lp_realm(), lp_realm());
- asprintf(&host_princ_s[0], "%s$@%s", my_name, lp_realm());
- asprintf(&host_princ_s[1], "%s$@%s", my_NAME, lp_realm());
- asprintf(&host_princ_s[2], "host/%s@%s", my_name, lp_realm());
- asprintf(&host_princ_s[3], "host/%s@%s", my_NAME, lp_realm());
- asprintf(&host_princ_s[4], "host/%s@%s", my_fqdn, lp_realm());
- asprintf(&host_princ_s[5], "host/%s@%s", my_Fqdn, lp_realm());
- asprintf(&host_princ_s[6], "HOST/%s@%s", my_name, lp_realm());
- asprintf(&host_princ_s[7], "HOST/%s@%s", my_NAME, lp_realm());
- asprintf(&host_princ_s[8], "HOST/%s@%s", my_fqdn, lp_realm());
- asprintf(&host_princ_s[9], "HOST/%s@%s", my_Fqdn, lp_realm());
- asprintf(&host_princ_s[10], "cifs/%s@%s", my_name, lp_realm());
- asprintf(&host_princ_s[11], "cifs/%s@%s", my_NAME, lp_realm());
- asprintf(&host_princ_s[12], "cifs/%s@%s", my_fqdn, lp_realm());
- asprintf(&host_princ_s[13], "cifs/%s@%s", my_Fqdn, lp_realm());
- asprintf(&host_princ_s[14], "CIFS/%s@%s", my_name, lp_realm());
- asprintf(&host_princ_s[15], "CIFS/%s@%s", my_NAME, lp_realm());
- asprintf(&host_princ_s[16], "CIFS/%s@%s", my_fqdn, lp_realm());
- asprintf(&host_princ_s[17], "CIFS/%s@%s", my_Fqdn, lp_realm());
-
- /* Now try to verify the ticket using the key associated with each of
- * the principals which we think clients will expect us to be
- * participating as. */
- for (i = 0; i < sizeof(host_princ_s) / sizeof(host_princ_s[0]); i++) {
- host_princ = NULL;
- ret = krb5_parse_name(context, host_princ_s[i], &host_princ);
+ /* Iterate through the keytab. For each key, if the principal
+ * name case-insensitively matches one of the allowed formats,
+ * try verifying the ticket using that principal. */
+ while ((ret = krb5_kt_next_entry(context, keytab, &entry, &cursor)) != KRB5_KT_END) {
if (ret) {
- DEBUG(1, ("ads_keytab_verify_ticket: krb5_parse_name(%s) failed (%s)\n",
- host_princ_s[i], error_message(ret)));
+ DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_next_entry failed (%s)\n", error_message(ret)));
goto out;
}
- p_packet->length = ticket->length;
- p_packet->data = (krb5_pointer)ticket->data;
- *pp_tkt = NULL;
- ret = krb5_rd_req(context, &auth_context, p_packet, host_princ, keytab, NULL, pp_tkt);
- krb5_free_principal(context, host_princ);
+ ret = krb5_unparse_name(context, entry.principal, &host_princ_s);
if (ret) {
- DEBUG(10, ("krb5_rd_req(%s) failed: %s\n", host_princ_s[i], error_message(ret)));
- } else {
- DEBUG(10,("krb5_rd_req succeeded for principal %s\n", host_princ_s[i]));
- auth_ok = True;
+ DEBUG(1, ("ads_keytab_verify_ticket: krb5_unparse_name failed (%s)\n", error_message(ret)));
+ goto out;
+ }
+ for (i = 0; i < sizeof(valid_princ_formats) / sizeof(valid_princ_formats[0]); i++) {
+ if (StrCaseCmp(host_princ_s, valid_princ_formats[i]) == 0) {
+ p_packet->length = ticket->length;
+ p_packet->data = (krb5_pointer)ticket->data;
+ *pp_tkt = NULL;
+ ret = krb5_rd_req(context, &auth_context, p_packet, entry.principal, keytab, NULL, pp_tkt);
+ if (ret) {
+ DEBUG(10, ("krb5_rd_req(%s) failed: %s\n", host_princ_s, error_message(ret)));
+ } else {
+ DEBUG(10, ("krb5_rd_req succeeded for principal %s\n", host_princ_s));
+ auth_ok = True;
+ break;
+ }
+ }
+ }
+ krb5_free_unparsed_name(context, host_princ_s);
+ host_princ_s = NULL;
+ if (auth_ok) {
break;
- }
+ }
}
- for (i = 0; i < sizeof(host_princ_s) / sizeof(host_princ_s[0]); i++) {
- SAFE_FREE(host_princ_s[i]);
- }
-
out:
+ for (i = 0; i < sizeof(valid_princ_formats) / sizeof(valid_princ_formats[0]); i++) {
+ SAFE_FREE(valid_princ_formats[i]);
+ }
+ if (host_princ_s) {
+ krb5_free_unparsed_name(context, host_princ_s);
+ }
+ if (cursor) {
+ krb5_kt_end_seq_get(context, keytab, &cursor);
+ }
if (keytab) {
krb5_kt_close(context, keytab);
}
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