2112. [security] Warn if weak RSA exponent is used. [RT #16460]

diff --git a/CHANGES b/CHANGES
index 44112d37f08a6b5e06c8033711916148d1333f9c..b716f5e36c048ddbcca16cfc15613fd65492e966 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,5 @@
+2112.  [security]      Warn if weak RSA exponent is used. [RT #16460]
+
 2111.  [bug]           Fix a number of errors reported by Coverity.
                        [RT #16507]
 

diff --git a/bin/named/server.c b/bin/named/server.c
index bcde30f092866c7e074b6053390df63c76b1048e..6ae31cb699d0524e5f3df2a2b812bec52091cafe 100644 (file)
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: server.c,v 1.419.18.48 2006/07/24 05:52:44 marka Exp $ */
+/* $Id: server.c,v 1.419.18.49 2006/12/07 05:24:19 marka Exp $ */
 
 /*! \file */
 
@@ -346,6 +346,13 @@ configure_view_dnsseckey(const cfg_obj_t *vconfig, const cfg_obj_t *key,
        keystruct.datalen = r.length;
        keystruct.data = r.base;
 
+       if ((keystruct.algorithm == DST_ALG_RSASHA1 ||
+            keystruct.algorithm == DST_ALG_RSAMD5) &&
+           r.length > 1 && r.base[0] == 1 && r.base[1] == 3)
+               cfg_obj_log(key, ns_g_lctx, ISC_LOG_WARNING,
+                           "trusted key '%s' has a weak exponent",
+                           keynamestr);
+
        CHECK(dns_rdata_fromstruct(NULL,
                                   keystruct.common.rdclass,
                                   keystruct.common.rdtype,

diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index 63eaed8a1c1797a6ed8d9dd73cc8572ee0e3f5eb..1516f95d0b613219b461b590f95e0ad0fd117b36 100644 (file)
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: zone.c,v 1.410.18.45 2006/07/19 00:58:01 marka Exp $ */
+/* $Id: zone.c,v 1.410.18.46 2006/12/07 05:24:20 marka Exp $ */
 
 /*! \file */
 
@@ -1267,7 +1267,7 @@ zone_gotreadhandle(isc_task_t *task, isc_event_t *event) {
                options |= DNS_MASTER_CHECKMXFAIL;
        if (DNS_ZONE_OPTION(load->zone, DNS_ZONEOPT_CHECKWILDCARD))
                options |= DNS_MASTER_CHECKWILDCARD;
-       result = dns_master_loadfileinc2(load->zone->masterfile,
+       result = dns_master_loadfileinc2(load->zone->masterfile,
                                         dns_db_origin(load->db),
                                         dns_db_origin(load->db),
                                         load->zone->rdclass,
@@ -1477,7 +1477,7 @@ zone_check_mx(dns_zone_t *zone, dns_db_t *db, dns_name_t *name,
                if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNOREMXCNAME)) {
                        dns_name_format(foundname, altbuf, sizeof altbuf);
                        dns_zone_log(zone, level, "%s/MX '%s' is below a DNAME"
-                                    " '%s' (illegal)", ownerbuf, namebuf,
+                                    " '%s' (illegal)", ownerbuf, namebuf,
                                     altbuf);
                }
                return ((level == ISC_LOG_WARNING) ? ISC_TRUE : ISC_FALSE);
@@ -1579,7 +1579,7 @@ zone_check_srv(dns_zone_t *zone, dns_db_t *db, dns_name_t *name,
 
 static isc_boolean_t
 zone_check_glue(dns_zone_t *zone, dns_db_t *db, dns_name_t *name,
-               dns_name_t *owner)
+               dns_name_t *owner)
 {
        isc_boolean_t answer = ISC_TRUE;
        isc_result_t result, tresult;
@@ -1812,6 +1812,75 @@ integrity_checks(dns_zone_t *zone, dns_db_t *db) {
        return (ok);
 }
 
+/*
+ * OpenSSL verification of RSA keys with exponent 3 is known to be
+ * broken prior OpenSSL 0.9.8c/0.9.7k.  Look for such keys and warn
+ * if they are in use.
+ */
+static void
+zone_check_dnskeys(dns_zone_t *zone, dns_db_t *db) {
+       dns_dbnode_t *node = NULL;
+       dns_dbversion_t *version = NULL;
+       dns_rdata_dnskey_t dnskey;
+       dns_rdata_t rdata = DNS_RDATA_INIT;
+       dns_rdataset_t rdataset;
+       isc_result_t result;
+       isc_boolean_t logit, foundrsa = ISC_FALSE, foundmd5 = ISC_FALSE;
+       const char *algorithm;
+
+       result = dns_db_findnode(db, &zone->origin, ISC_FALSE, &node);
+       if (result != ISC_R_SUCCESS)
+               goto cleanup;
+
+       dns_db_currentversion(db, &version);
+       dns_rdataset_init(&rdataset);
+       result = dns_db_findrdataset(db, node, version, dns_rdatatype_dnskey,
+                                    dns_rdatatype_none, 0, &rdataset, NULL);
+       if (result != ISC_R_SUCCESS)
+               goto cleanup;
+
+       for (result = dns_rdataset_first(&rdataset);
+            result == ISC_R_SUCCESS;
+            result = dns_rdataset_next(&rdataset)) 
+       {
+               dns_rdataset_current(&rdataset, &rdata);
+               result = dns_rdata_tostruct(&rdata, &dnskey, NULL);
+               INSIST(result == ISC_R_SUCCESS);
+               
+               if ((dnskey.algorithm == DST_ALG_RSASHA1 ||
+                    dnskey.algorithm == DST_ALG_RSAMD5) &&
+                    dnskey.datalen > 1 && dnskey.data[0] == 1 &&
+                    dnskey.data[1] == 3)
+               {
+                       if (dnskey.algorithm == DST_ALG_RSASHA1) {
+                               logit = !foundrsa;
+                               foundrsa = ISC_TRUE;
+                               algorithm = "RSASHA1";
+                       } else {
+                               logit = !foundmd5;
+                               foundmd5 = ISC_TRUE;
+                               algorithm = "RSAMD5";
+                       }
+                       if (logit)
+                               dns_zone_log(zone, ISC_LOG_WARNING,
+                                            "weak %s (%u) key found "
+                                            "(exponent=3)", algorithm,
+                                            dnskey.algorithm);
+                       if (foundrsa && foundmd5)
+                               break;
+               }
+               dns_rdata_reset(&rdata);
+       }
+       dns_rdataset_disassociate(&rdataset);
+
+ cleanup:
+       if (node != NULL)
+               dns_db_detachnode(db, &node);
+       if (version != NULL)
+               dns_db_closeversion(db, &version, ISC_FALSE);
+       
+}
+
 static isc_result_t
 zone_postload(dns_zone_t *zone, dns_db_t *db, isc_time_t loadtime,
              isc_result_t result)
@@ -2010,6 +2079,12 @@ zone_postload(dns_zone_t *zone, dns_db_t *db, isc_time_t loadtime,
                goto cleanup;
        }
 
+       /*
+        * Check for weak DNSKEY's.
+        */
+       if (zone->type == dns_zone_master)
+               zone_check_dnskeys(zone, db);
+
 #if 0
        /* destroy notification example. */
        {
@@ -3589,7 +3664,7 @@ notify_send_toaddr(isc_task_t *task, isc_event_t *event) {
         */
        if (isc_sockaddr_pf(&notify->dst) == PF_INET6 &&
            IN6_IS_ADDR_V4MAPPED(&notify->dst.type.sin6.sin6_addr)) {
-               isc_sockaddr_format(&notify->dst, addrbuf, sizeof(addrbuf));
+               isc_sockaddr_format(&notify->dst, addrbuf, sizeof(addrbuf));
                notify_log(notify->zone, ISC_LOG_DEBUG(3),
                           "notify: ignoring IPv6 mapped IPV4 address: %s",
                           addrbuf);
@@ -4796,7 +4871,7 @@ soa_query(isc_task_t *task, isc_event_t *event) {
                        char namebuf[DNS_NAME_FORMATSIZE];
                        dns_name_format(keyname, namebuf, sizeof(namebuf));
                        dns_zone_log(zone, ISC_LOG_ERROR,
-                                    "unable to find key: %s", namebuf);
+                                    "unable to find key: %s", namebuf);
                }
        }
        if (key == NULL)
@@ -5021,7 +5096,7 @@ ns_query(dns_zone_t *zone, dns_rdataset_t *soardataset, dns_stub_t *stub) {
                        char namebuf[DNS_NAME_FORMATSIZE];
                        dns_name_format(keyname, namebuf, sizeof(namebuf));
                        dns_zone_log(zone, ISC_LOG_ERROR,
-                                    "unable to find key: %s", namebuf);
+                                    "unable to find key: %s", namebuf);
                }
        }
        if (key == NULL)
@@ -5108,7 +5183,7 @@ ns_query(dns_zone_t *zone, dns_rdataset_t *soardataset, dns_stub_t *stub) {
        if (message != NULL)
                dns_message_destroy(&message);
   unlock:
-        if (key != NULL)
+       if (key != NULL)
                dns_tsigkey_detach(&key);
        UNLOCK_ZONE(zone);
        return;