metainfo: Add HashBytes

metainfo/hash.go

@@ -1,6 +1,7 @@
 package metainfo
 
 import (
+	"crypto/sha1"
 	"encoding/hex"
 	"fmt"
 )
@@ -34,3 +35,10 @@ func (h *Hash) FromHexString(s string) (err error) {
 	}
 	return
 }
+
+func HashBytes(b []byte) (ret Hash) {
+	hasher := sha1.New()
+	hasher.Write(b)
+	copy(ret[:], hasher.Sum(nil))
+	return
+}