Catching more principals in ads_keytab_verify_ticket()
Doug VanLeuven
roamdad at sonic.net
Thu Mar 10 11:56:03 GMT 2005
Jeremy Allison wrote:
>I'm not going to add either patch until you huys have both
>agreed. When you do - re-mail me the patch you want going in
>and I'll look at that.
>
>The kerberos keytab stuff is complex enough that the last
>thing I want to see is "warring patches" that fix different
>things for different people.
>
>
The rc4-hmac works ok.
The des-cbc-md5 works ok.
After having studied it and run the experiments, it seems like a real
good idea.
I didn't change anything from his submittal except a couple debug
statements. I'm finding it really handy to have a message all key
matches failed. Sort of a heads up something is missing from the keytab.
Thanks a lot Michael, it's a lot cleaner.
Jeremy, I'm still working on what to do for libads/kerberos_keytab.c.
Some issues came up during the des testing that have a direct bearing on
bug 2414 you asked about.
Regards, Doug
-------------- next part --------------
Index: libads/kerberos_verify.c
===================================================================
--- libads/kerberos_verify.c (revision 5575)
+++ libads/kerberos_verify.c (working copy)
@@ -43,10 +43,10 @@
BOOL auth_ok = False;
krb5_keytab keytab = NULL;
fstring my_fqdn, my_name;
- fstring my_Fqdn, my_NAME;
- char *p_fqdn;
- char *host_princ_s[18];
- krb5_principal host_princ;
+ krb5_kt_cursor cursor = NULL;
+ char *valid_princ_formats[7] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL };
+ char *host_princ_s = NULL;
+ krb5_keytab_entry entry;
int i;
ret = krb5_kt_default(context, &keytab);
@@ -55,75 +55,79 @@
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;
+ }
+ /* Generate the list of principal names which we expect
+ * clients might want to use for authenticating to the file
+ * service. We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
+
fstrcpy(my_name, global_myname());
- strlower_m(my_name);
-
- fstrcpy(my_NAME, global_myname());
- strupper_m(my_NAME);
-
my_fqdn[0] = '\0';
name_to_fqdn(my_fqdn, global_myname());
- strlower_m(my_fqdn);
- p_fqdn = strchr_m(my_fqdn, '.');
- fstrcpy(my_Fqdn, my_NAME);
- if (p_fqdn) {
- fstrcat(my_Fqdn, p_fqdn);
- }
+ asprintf(&valid_princ_formats[0], "%s$@%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, ("ads_keytab_verify_ticket: krb5_rd_req(%s) failed: %s\n",
+ host_princ_s, error_message(ret)));
+ } else {
+ DEBUG(3, ("ads_keytab_verify_ticket: 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:
+ if (! auth_ok) {
+ DEBUG(3, ("ads_keytab_verify_ticket: krb5_rd_req failed for all matched principals\n"));
}
- 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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