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author | Tyler Davis <tydavis@gmail.com> | 2018-02-28 23:00:21 +0000 |
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committer | Tyler Davis <tydavis@gmail.com> | 2018-02-28 23:00:21 +0000 |
commit | 0e8a5cebd8548bfe95c5c7808da7da0f651f0c3a (patch) | |
tree | 469486208835d832e16940bac58a06f32bd723d8 /vendor/github.com/miekg/dns/nsecx.go | |
parent | 93b7b9300254e80dc7b17556b5d6a8b7d7e9607a (diff) | |
download | dnstracker-0e8a5cebd8548bfe95c5c7808da7da0f651f0c3a.tar.gz dnstracker-0e8a5cebd8548bfe95c5c7808da7da0f651f0c3a.zip |
Add dependencies
Diffstat (limited to 'vendor/github.com/miekg/dns/nsecx.go')
-rw-r--r-- | vendor/github.com/miekg/dns/nsecx.go | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/nsecx.go b/vendor/github.com/miekg/dns/nsecx.go new file mode 100644 index 0000000..9b908c4 --- /dev/null +++ b/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 +} |