status-go/vendor/github.com/miekg/dns/hash.go

32 lines
875 B
Go

package dns
import (
"bytes"
"crypto"
"hash"
)
// identityHash will not hash, it only buffers the data written into it and returns it as-is.
type identityHash struct {
b *bytes.Buffer
}
// Implement the hash.Hash interface.
func (i identityHash) Write(b []byte) (int, error) { return i.b.Write(b) }
func (i identityHash) Size() int { return i.b.Len() }
func (i identityHash) BlockSize() int { return 1024 }
func (i identityHash) Reset() { i.b.Reset() }
func (i identityHash) Sum(b []byte) []byte { return append(b, i.b.Bytes()...) }
func hashFromAlgorithm(alg uint8) (hash.Hash, crypto.Hash, error) {
hashnumber, ok := AlgorithmToHash[alg]
if !ok {
return nil, 0, ErrAlg
}
if hashnumber == 0 {
return identityHash{b: &bytes.Buffer{}}, hashnumber, nil
}
return hashnumber.New(), hashnumber, nil
}