55 lines
1.1 KiB
Go
55 lines
1.1 KiB
Go
// Copyright 2011 Miek Gieben. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package dns
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import (
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"crypto/sha1"
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"hash"
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"io"
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"strings"
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)
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type saltWireFmt struct {
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Salt string `dns:"size-hex"`
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}
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// HashName hashes a string (label) according to RFC 5155. It returns the hashed string.
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func HashName(label string, ha uint8, iter uint16, salt string) string {
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saltwire := new(saltWireFmt)
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saltwire.Salt = salt
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wire := make([]byte, DefaultMsgSize)
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n, err := PackStruct(saltwire, wire, 0)
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if err != nil {
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return ""
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}
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wire = wire[:n]
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name := make([]byte, 255)
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off, err := PackDomainName(strings.ToLower(label), name, 0, nil, false)
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if err != nil {
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return ""
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}
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name = name[:off]
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var s hash.Hash
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switch ha {
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case SHA1:
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s = sha1.New()
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default:
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return ""
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}
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// k = 0
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name = append(name, wire...)
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io.WriteString(s, string(name))
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nsec3 := s.Sum(nil)
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// k > 0
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for k := uint16(0); k < iter; k++ {
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s.Reset()
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nsec3 = append(nsec3, wire...)
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io.WriteString(s, string(nsec3))
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nsec3 = s.Sum(nil)
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}
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return unpackBase32(nsec3)
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}
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