HEIMDAL:hdb: export a hdb_enctype_supported() helper function

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13135

Signed-off-by: Stefan Metzmacher <metze@samba.org>

4 files changed, 39 insertions, 10 deletions

diff --git a/source4/heimdal/kdc/kerberos5.c b/source4/heimdal/kdc/kerberos5.c
index db2c6262116..c6ec65ee926 100644
--- a/source4/heimdal/kdc/kerberos5.c
+++ b/source4/heimdal/kdc/kerberos5.c
@@ -131,7 +131,7 @@ _kdc_find_etype(krb5_context context, krb5_boolean use_strongest_session_key,
     krb5_error_code ret;
     krb5_salt def_salt;
     krb5_enctype enctype = ETYPE_NULL;
-    Key *key;
+    Key *key = NULL;
     int i;
 
     /* We'll want to avoid keys with v4 salted keys in the pre-auth case... */
@@ -159,29 +159,34 @@ _kdc_find_etype(krb5_context context, krb5_boolean use_strongest_session_key,
 
 	/* drive the search with local supported enctypes list */
 	p = krb5_kerberos_enctypes(context);
-	for (i = 0; p[i] != ETYPE_NULL && enctype == ETYPE_NULL; i++) {
+	for (i = 0; p[i] != ETYPE_NULL && key == NULL; i++) {
 	    if (krb5_enctype_valid(context, p[i]) != 0)
 		continue;
 
 	    /* check that the client supports it too */
-	    for (j = 0; j < len && enctype == ETYPE_NULL; j++) {
+	    for (j = 0; j < len && key == NULL; j++) {
 		if (p[i] != etypes[j])
 		    continue;
 		/* save best of union of { client, crypto system } */
 		if (clientbest == ETYPE_NULL)
 		    clientbest = p[i];
+		if (enctype == ETYPE_NULL) {
+		    ret = hdb_enctype_supported(context, &princ->entry, p[i]);
+		    if (ret == 0) {
+			enctype = p[i];
+		    }
+		}
 		/* check target princ support */
 		ret = hdb_enctype2key(context, &princ->entry, p[i], &key);
 		if (ret)
 		    continue;
 		if (is_preauth && !is_default_salt_p(&def_salt, key))
 		    continue;
-		enctype = p[i];
 	    }
 	}
 	if (clientbest != ETYPE_NULL && enctype == ETYPE_NULL)
 	    enctype = clientbest;
-	else if (enctype == ETYPE_NULL)
+	else if (key == NULL)
 	    ret = KRB5KDC_ERR_ETYPE_NOSUPP;
 	if (ret == 0 && ret_enctype != NULL)
 	    *ret_enctype = enctype;
diff --git a/source4/heimdal/kdc/krb5tgs.c b/source4/heimdal/kdc/krb5tgs.c
index a71cfbff66c..a91b319c630 100644
--- a/source4/heimdal/kdc/krb5tgs.c
+++ b/source4/heimdal/kdc/krb5tgs.c
@@ -1703,7 +1703,7 @@ server_lookup:
 
 	    ret = _kdc_find_etype(context,
 				  config->tgs_use_strongest_session_key, FALSE,
-				  server, b->etype.val, b->etype.len, NULL,
+				  server, b->etype.val, b->etype.len, &etype,
 				  &skey);
 	    if(ret) {
 		kdc_log(context, config, 0,
@@ -1711,7 +1711,6 @@ server_lookup:
 		goto out;
 	    }
 	    ekey = &skey->key;
-	    etype = skey->key.keytype;
 	    kvno = server->entry.kvno;
 	}
 
diff --git a/source4/heimdal/lib/hdb/hdb.c b/source4/heimdal/lib/hdb/hdb.c
index 5dc5a0957e0..4c8df930b0c 100644
--- a/source4/heimdal/lib/hdb/hdb.c
+++ b/source4/heimdal/lib/hdb/hdb.c
@@ -93,11 +93,12 @@ static struct hdb_method dbmetod =
 #endif
 
 
-krb5_error_code
-hdb_next_enctype2key(krb5_context context,
+static krb5_error_code
+_hdb_next_enctype2key(krb5_context context,
 		     const hdb_entry *e,
 		     krb5_enctype enctype,
-		     Key **key)
+		     Key **key,
+		     bool require_key)
 {
     Key *k;
 
@@ -105,6 +106,10 @@ hdb_next_enctype2key(krb5_context context,
 	 k < e->keys.val + e->keys.len;
 	 k++)
     {
+	if (require_key && k->key.keyvalue.length == 0) {
+	    continue;
+	}
+
 	if(k->key.keytype == enctype){
 	    *key = k;
 	    return 0;
@@ -116,6 +121,16 @@ hdb_next_enctype2key(krb5_context context,
     return KRB5_PROG_ETYPE_NOSUPP; /* XXX */
 }
 
+
+krb5_error_code
+hdb_next_enctype2key(krb5_context context,
+		     const hdb_entry *e,
+		     krb5_enctype enctype,
+		     Key **key)
+{
+	return _hdb_next_enctype2key(context, e, enctype, key, true);
+}
+
 krb5_error_code
 hdb_enctype2key(krb5_context context,
 		hdb_entry *e,
@@ -126,6 +141,15 @@ hdb_enctype2key(krb5_context context,
     return hdb_next_enctype2key(context, e, enctype, key);
 }
 
+krb5_error_code
+hdb_enctype_supported(krb5_context context,
+		hdb_entry *e,
+		krb5_enctype enctype)
+{
+    Key *key = NULL;
+    return _hdb_next_enctype2key(context, e, enctype, &key, false);
+}
+
 void
 hdb_free_key(Key *key)
 {
diff --git a/source4/heimdal/lib/hdb/version-script.map b/source4/heimdal/lib/hdb/version-script.map
index f80fb78a654..c4bd8f4cd44 100644
--- a/source4/heimdal/lib/hdb/version-script.map
+++ b/source4/heimdal/lib/hdb/version-script.map
@@ -20,6 +20,7 @@ HEIMDAL_HDB_1.0 {
 		hdb_dbinfo_get_realm;
 		hdb_default_db;
 		hdb_enctype2key;
+		hdb_enctype_supported;
 		hdb_entry2string;
 		hdb_entry2value;
 		hdb_entry_alias2value;