Merge pull request #201 from Bytom/v0.1

[bytom/vapor.git] / vendor / github.com / miekg / dns / nsecx.go

diff --git a/vendor/github.com/miekg/dns/nsecx.go b/vendor/github.com/miekg/dns/nsecx.go
new file mode 100644 (file)
index 0000000..8f071a4
--- /dev/null
+++ b/vendor/github.com/miekg/dns/nsecx.go
@@ -0,0 +1,95 @@
+package dns
+
+import (
+       "crypto/sha1"
+       "encoding/hex"
+       "strings"
+)
+
+// HashName hashes a string (label) according to RFC 5155. It returns the hashed string in uppercase.
+func HashName(label string, ha uint8, iter uint16, salt string) string {
+       if ha != SHA1 {
+               return ""
+       }
+
+       wireSalt := make([]byte, hex.DecodedLen(len(salt)))
+       n, err := packStringHex(salt, wireSalt, 0)
+       if err != nil {
+               return ""
+       }
+       wireSalt = wireSalt[:n]
+
+       name := make([]byte, 255)
+       off, err := PackDomainName(strings.ToLower(label), name, 0, nil, false)
+       if err != nil {
+               return ""
+       }
+       name = name[:off]
+
+       s := sha1.New()
+       // k = 0
+       s.Write(name)
+       s.Write(wireSalt)
+       nsec3 := s.Sum(nil)
+
+       // k > 0
+       for k := uint16(0); k < iter; k++ {
+               s.Reset()
+               s.Write(nsec3)
+               s.Write(wireSalt)
+               nsec3 = s.Sum(nsec3[:0])
+       }
+
+       return toBase32(nsec3)
+}
+
+// Cover returns true if a name is covered by the NSEC3 record
+func (rr *NSEC3) Cover(name string) bool {
+       nameHash := HashName(name, rr.Hash, rr.Iterations, rr.Salt)
+       owner := strings.ToUpper(rr.Hdr.Name)
+       labelIndices := Split(owner)
+       if len(labelIndices) < 2 {
+               return false
+       }
+       ownerHash := owner[:labelIndices[1]-1]
+       ownerZone := owner[labelIndices[1]:]
+       if !IsSubDomain(ownerZone, strings.ToUpper(name)) { // name is outside owner zone
+               return false
+       }
+
+       nextHash := rr.NextDomain
+
+       // if empty interval found, try cover wildcard hashes so nameHash shouldn't match with ownerHash
+       if ownerHash == nextHash && nameHash != ownerHash { // empty interval
+               return true
+       }
+       if ownerHash > nextHash { // end of zone
+               if nameHash > ownerHash { // covered since there is nothing after ownerHash
+                       return true
+               }
+               return nameHash < nextHash // if nameHash is before beginning of zone it is covered
+       }
+       if nameHash < ownerHash { // nameHash is before ownerHash, not covered
+               return false
+       }
+       return nameHash < nextHash // if nameHash is before nextHash is it covered (between ownerHash and nextHash)
+}
+
+// Match returns true if a name matches the NSEC3 record
+func (rr *NSEC3) Match(name string) bool {
+       nameHash := HashName(name, rr.Hash, rr.Iterations, rr.Salt)
+       owner := strings.ToUpper(rr.Hdr.Name)
+       labelIndices := Split(owner)
+       if len(labelIndices) < 2 {
+               return false
+       }
+       ownerHash := owner[:labelIndices[1]-1]
+       ownerZone := owner[labelIndices[1]:]
+       if !IsSubDomain(ownerZone, strings.ToUpper(name)) { // name is outside owner zone
+               return false
+       }
+       if ownerHash == nameHash {
+               return true
+       }
+       return false
+}