Slightly refactored error messages

[gogost.git] / gost3410 / vko.go

diff --git a/gost3410/vko.go b/gost3410/vko.go
index 88d0a269be09c586cddd3fa4907cd926a0867b80..c0afa9995daf953dcf2cd7b1948abfd0a0714c04 100644 (file)
--- a/gost3410/vko.go
+++ b/gost3410/vko.go
@@ -16,19 +16,20 @@
 package gost3410
 
 import (
+       "fmt"
        "math/big"
 )
 
 func (prv *PrivateKey) KEK(pub *PublicKey, ukm *big.Int) ([]byte, error) {
        keyX, keyY, err := prv.C.Exp(prv.Key, pub.X, pub.Y)
        if err != nil {
-               return nil, err
+               return nil, fmt.Errorf("gogost/gost3410.PrivateKey.KEK: %w", err)
        }
        u := big.NewInt(0).Set(ukm).Mul(ukm, prv.C.Co)
        if u.Cmp(bigInt1) != 0 {
                keyX, keyY, err = prv.C.Exp(u, keyX, keyY)
                if err != nil {
-                       return nil, err
+                       return nil, fmt.Errorf("gogost/gost3410.PrivateKey.KEK: %w", err)
                }
        }
        pk := PublicKey{prv.C, keyX, keyY}