FedP2P/metainfo/hash.go

50 lines
756 B
Go

package metainfo
import (
"crypto/sha1"
"encoding/hex"
"fmt"
)
// 20-byte SHA1 hash used for info and pieces.
type Hash [20]byte
func (h Hash) Bytes() []byte {
return h[:]
}
func (h Hash) AsString() string {
return string(h[:])
}
func (h Hash) HexString() string {
return fmt.Sprintf("%x", h[:])
}
func (h *Hash) FromHexString(s string) (err error) {
if len(s) != 40 {
err = fmt.Errorf("hash hex string has bad length: %d", len(s))
return
}
n, err := hex.Decode(h[:], []byte(s))
if err != nil {
return
}
if n != 20 {
panic(n)
}
return
}
func NewHashFromHex(s string) (h Hash) {
h.FromHexString(s)
return
}
func HashBytes(b []byte) (ret Hash) {
hasher := sha1.New()
hasher.Write(b)
copy(ret[:], hasher.Sum(nil))
return
}