X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=mgm%2Fmode.go;h=e874dd372f0bc07343dacc496701ddf3a78a0118;hb=c40d1e5634cf6d540d908a57423f4b504e39f186;hp=fdbfa4277fad5577b2fc1af15a2857e547a4099c;hpb=c07494bbd559b9d00f391e28cfd070e18afe9900;p=gogost.git

diff --git a/mgm/mode.go b/mgm/mode.go
index fdbfa42..e874dd3 100644
--- a/mgm/mode.go
+++ b/mgm/mode.go
@@ -1,5 +1,5 @@
 // GoGOST -- Pure Go GOST cryptographic functions library
-// Copyright (C) 2015-2019 Sergey Matveev <stargrave@stargrave.org>
+// Copyright (C) 2015-2020 Sergey Matveev <stargrave@stargrave.org>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -61,10 +61,10 @@ type MGM struct {
 func NewMGM(cipher cipher.Block, tagSize int) (cipher.AEAD, error) {
 	blockSize := cipher.BlockSize()
 	if !(blockSize == 8 || blockSize == 16) {
-		return nil, errors.New("MGM supports only 64/128 blocksizes")
+		return nil, errors.New("gogost/mgm: only 64/128 blocksizes allowed")
 	}
 	if tagSize < 4 || tagSize > blockSize {
-		return nil, errors.New("invalid tag size")
+		return nil, errors.New("gogost/mgm: invalid tag size")
 	}
 	mgm := MGM{
 		maxSize:   uint64(1<<uint(blockSize*8/2) - 1),
@@ -242,7 +242,7 @@ func (mgm *MGM) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, err
 	copy(mgm.icn, nonce)
 	mgm.auth(mgm.sum, ct, additionalData)
 	if !hmac.Equal(mgm.sum[:mgm.tagSize], ciphertext[len(ciphertext)-mgm.tagSize:]) {
-		return nil, errors.New("invalid authentication tag")
+		return nil, errors.New("gogost/mgm: invalid authentication tag")
 	}
 	mgm.crypt(out, ct)
 	return ret, nil