fix lint warnings

pkcs11/ecdsa.go

@@ -53,11 +53,11 @@ func getPublic(point []byte, curve elliptic.Curve) (pub crypto.PublicKey, err er
 	}
 	ecdsaPub.X, ecdsaPub.Y = elliptic.Unmarshal(ecdsaPub.Curve, point[:pointLength])
 	if ecdsaPub.X == nil {
-		err = fmt.Errorf("failed to decode CKA_EC_POINT")
+		err = errors.New("failed to decode CKA_EC_POINT")
 		return
 	}
 	if !ecdsaPub.Curve.IsOnCurve(ecdsaPub.X, ecdsaPub.Y) {
-		err = fmt.Errorf("public key is not on curve")
+		err = errors.New("public key is not on curve")
 		return
 	}
 

pkcs11/login.go

@@ -66,7 +66,7 @@ func openLoginSession(context PKCS11Ctx, slot uint, userPin string) (p11.Session
 		err2 := context.CloseSession(session)
 		// append CloseSession error to Login error
 		if err2 != nil {
-			return 0, fmt.Errorf(err.Error() + ", CloseSession: " + err2.Error())
+			return 0, errors.New(err.Error() + ", CloseSession: " + err2.Error())
 		}
 		return 0, err
 	}

pkcs11/p11signer.go

@@ -7,7 +7,6 @@ import (
 	"crypto"
 	"crypto/x509"
 	"errors"
-	"fmt"
 	"io"
 
 	p11 "github.com/miekg/pkcs11"
@@ -34,7 +33,7 @@ func makeSigner(context PKCS11Ctx, slot uint, tokenLabel string, keyType x509.Pu
 		err2 := context.CloseSession(session)
 		// append CloseSession error to getPrivateKey error
 		if err2 != nil {
-			return nil, fmt.Errorf(err.Error() + ", CloseSession: " + err2.Error())
+			return nil, errors.New(err.Error() + ", CloseSession: " + err2.Error())
 		}
 		return nil, err
 	}
@@ -45,7 +44,7 @@ func makeSigner(context PKCS11Ctx, slot uint, tokenLabel string, keyType x509.Pu
 		err2 := context.CloseSession(session)
 		// append CloseSession error to getPublicKey error
 		if err2 != nil {
-			return nil, fmt.Errorf(err.Error() + ", CloseSession: " + err2.Error())
+			return nil, errors.New(err.Error() + ", CloseSession: " + err2.Error())
 		}
 		return nil, err
 	}

pkcs11/pkcs11.go

@@ -38,7 +38,7 @@ func initPKCS11Context(modulePath string) (*p11.Ctx, error) {
 	context := p11.New(modulePath)
 
 	if context == nil {
-		return nil, fmt.Errorf("unable to load PKCS#11 module:" + modulePath)
+		return nil, errors.New("unable to load PKCS#11 module:" + modulePath)
 	}
 
 	err := context.Initialize()

pkcs11/work.go

@@ -274,7 +274,7 @@ func (s *signerBlob) signData(ctx context.Context, signer signerWithSignAlgorith
 		pool.put(signer)
 	}()
 	if s.digest == nil {
-		e = fmt.Errorf("signBlob: cannot sign empty digest")
+		e = errors.New("signBlob: cannot sign empty digest")
 		return
 	}