Slightly more descriptive errors

[gogost.git] / internal / gost34112012 / hash.go

diff --git a/internal/gost34112012/hash.go b/internal/gost34112012/hash.go
index 5f6b707d87a05a001326d464693406e10aa60672..2c1b4b989448076194b81d06136ca6bda460ee66 100644 (file)
--- a/internal/gost34112012/hash.go
+++ b/internal/gost34112012/hash.go
@@ -21,6 +21,7 @@ import (
        "bytes"
        "encoding/binary"
        "errors"
+       "fmt"
 )
 
 const (
@@ -426,11 +427,12 @@ func (h *Hash) MarshalBinary() (data []byte, err error) {
 }
 
 func (h *Hash) UnmarshalBinary(data []byte) error {
-       if len(data) < len(MarshaledName)+1+8+3*BlockSize {
-               return errors.New("too short data")
+       expectedLen := len(MarshaledName) + 1 + 8 + 3*BlockSize
+       if len(data) < expectedLen {
+               return fmt.Errorf("gogost/internal/gost34112012: len(data) != %d", expectedLen)
        }
        if !bytes.HasPrefix(data, []byte(MarshaledName)) {
-               return errors.New("no hash name prefix")
+               return errors.New("gogost/internal/gost34112012: no hash name prefix")
        }
        idx := len(MarshaledName)
        h.size = int(data[idx])