1 files changed, 106 insertions, 0 deletions
diff --git a/vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/nsecx.go b/vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/nsecx.go
new file mode 100644
index 000000000..9b908c447
--- /dev/null
+++ b/vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/nsecx.go
@@ -0,0 +1,106 @@
+package dns
+
+import (
+	"crypto/sha1"
+	"hash"
+	"strings"
+)
+
+type saltWireFmt struct {
+	Salt string `dns:"size-hex"`
+}
+
+// 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 {
+	saltwire := new(saltWireFmt)
+	saltwire.Salt = salt
+	wire := make([]byte, DefaultMsgSize)
+	n, err := packSaltWire(saltwire, wire)
+	if err != nil {
+		return ""
+	}
+	wire = wire[:n]
+	name := make([]byte, 255)
+	off, err := PackDomainName(strings.ToLower(label), name, 0, nil, false)
+	if err != nil {
+		return ""
+	}
+	name = name[:off]
+	var s hash.Hash
+	switch ha {
+	case SHA1:
+		s = sha1.New()
+	default:
+		return ""
+	}
+
+	// k = 0
+	s.Write(name)
+	s.Write(wire)
+	nsec3 := s.Sum(nil)
+	// k > 0
+	for k := uint16(0); k < iter; k++ {
+		s.Reset()
+		s.Write(nsec3)
+		s.Write(wire)
+		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 ownerHash == nextHash { // empty interval
+		return false
+	}
+	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
+}
+
+func packSaltWire(sw *saltWireFmt, msg []byte) (int, error) {
+	off, err := packStringHex(sw.Salt, msg, 0)
+	if err != nil {
+		return off, err
+	}
+	return off, nil
+}