resolved: fix DNSSEC canonical ordering logic

When applying canonical DNSSEC ordering for an RRset only order by the
wire format of the RRs' RDATA, not by the full wire formatting. The RFC
isn't particularly clear about this, but this is apparently how it is
done. This fixes validation of pentagon.gov's DS RRset.

diff --git a/src/resolve/resolved-dns-dnssec.c b/src/resolve/resolved-dns-dnssec.c
index 606d6817796e490303af9a5da0eac9c4e472fecb..f2180c3e35280be0d75ad4ba696895cad71b257d 100644 (file)
--- a/src/resolve/resolved-dns-dnssec.c
+++ b/src/resolve/resolved-dns-dnssec.c
@@ -116,15 +116,15 @@ static int rr_compare(const void *a, const void *b) {
         assert(*y);
         assert((*y)->wire_format);
 
-        m = MIN((*x)->wire_format_size, (*y)->wire_format_size);
+        m = MIN(DNS_RESOURCE_RECORD_RDATA_SIZE(*x), DNS_RESOURCE_RECORD_RDATA_SIZE(*y));
 
-        r = memcmp((*x)->wire_format, (*y)->wire_format, m);
+        r = memcmp(DNS_RESOURCE_RECORD_RDATA(*x), DNS_RESOURCE_RECORD_RDATA(*y), m);
         if (r != 0)
                 return r;
 
-        if ((*x)->wire_format_size < (*y)->wire_format_size)
+        if (DNS_RESOURCE_RECORD_RDATA_SIZE(*x) < DNS_RESOURCE_RECORD_RDATA_SIZE(*y))
                 return -1;
-        else if ((*x)->wire_format_size > (*y)->wire_format_size)
+        else if (DNS_RESOURCE_RECORD_RDATA_SIZE(*x) > DNS_RESOURCE_RECORD_RDATA_SIZE(*y))
                 return 1;
 
         return 0;
@@ -605,12 +605,11 @@ int dnssec_verify_rrset(
                 md_add_uint16(md, rr->key->class);
                 md_add_uint32(md, rrsig->rrsig.original_ttl);
 
-                assert(rr->wire_format_rdata_offset <= rr->wire_format_size);
-                l = rr->wire_format_size - rr->wire_format_rdata_offset;
+                l = DNS_RESOURCE_RECORD_RDATA_SIZE(rr);
                 assert(l <= 0xFFFF);
 
                 md_add_uint16(md, (uint16_t) l);
-                gcry_md_write(md, (uint8_t*) rr->wire_format + rr->wire_format_rdata_offset, l);
+                gcry_md_write(md, DNS_RESOURCE_RECORD_RDATA(rr), l);
         }
 
         hash = gcry_md_read(md, 0);

diff --git a/src/resolve/resolved-dns-rr.h b/src/resolve/resolved-dns-rr.h
index 72bded7d481edd69be7d4d32a4fd5e6766797e36..26ab36401cedfb896c4aeb75f71e438278ff8924 100644 (file)
--- a/src/resolve/resolved-dns-rr.h
+++ b/src/resolve/resolved-dns-rr.h
@@ -236,7 +236,7 @@ struct DnsResourceRecord {
 };
 
 static inline const char* DNS_RESOURCE_KEY_NAME(const DnsResourceKey *key) {
-        if (_unlikely_(!key))
+        if (!key)
                 return NULL;
 
         if (key->_name)
@@ -245,6 +245,27 @@ static inline const char* DNS_RESOURCE_KEY_NAME(const DnsResourceKey *key) {
         return (char*) key + sizeof(DnsResourceKey);
 }
 
+static inline const void* DNS_RESOURCE_RECORD_RDATA(DnsResourceRecord *rr) {
+        if (!rr)
+                return NULL;
+
+        if (!rr->wire_format)
+                return NULL;
+
+        assert(rr->wire_format_rdata_offset <= rr->wire_format_size);
+        return (uint8_t*) rr->wire_format + rr->wire_format_rdata_offset;
+}
+
+static inline size_t DNS_RESOURCE_RECORD_RDATA_SIZE(DnsResourceRecord *rr) {
+        if (!rr)
+                return 0;
+        if (!rr->wire_format)
+                return 0;
+
+        assert(rr->wire_format_rdata_offset <= rr->wire_format_size);
+        return rr->wire_format_size - rr->wire_format_rdata_offset;
+}
+
 DnsResourceKey* dns_resource_key_new(uint16_t class, uint16_t type, const char *name);
 DnsResourceKey* dns_resource_key_new_redirect(const DnsResourceKey *key, const DnsResourceRecord *cname);
 int dns_resource_key_new_append_suffix(DnsResourceKey **ret, DnsResourceKey *key, char *name);