hash.go (875B)
1 package dns 2 3 import ( 4 "bytes" 5 "crypto" 6 "hash" 7 ) 8 9 // identityHash will not hash, it only buffers the data written into it and returns it as-is. 10 type identityHash struct { 11 b *bytes.Buffer 12 } 13 14 // Implement the hash.Hash interface. 15 16 func (i identityHash) Write(b []byte) (int, error) { return i.b.Write(b) } 17 func (i identityHash) Size() int { return i.b.Len() } 18 func (i identityHash) BlockSize() int { return 1024 } 19 func (i identityHash) Reset() { i.b.Reset() } 20 func (i identityHash) Sum(b []byte) []byte { return append(b, i.b.Bytes()...) } 21 22 func hashFromAlgorithm(alg uint8) (hash.Hash, crypto.Hash, error) { 23 hashnumber, ok := AlgorithmToHash[alg] 24 if !ok { 25 return nil, 0, ErrAlg 26 } 27 if hashnumber == 0 { 28 return identityHash{b: &bytes.Buffer{}}, hashnumber, nil 29 } 30 return hashnumber.New(), hashnumber, nil 31 }