/
kdf.go
53 lines (48 loc) · 1.37 KB
/
kdf.go
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// GoGOST -- Pure Go GOST cryptographic functions library
// Copyright (C) 2015-2024 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
// the Free Software Foundation, version 3 of the License.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package gost34112012256
import (
"crypto/hmac"
"hash"
)
type KDF struct {
h hash.Hash
}
func NewKDF(key []byte) *KDF {
return &KDF{hmac.New(New, key)}
}
func (kdf *KDF) Derive(dst, label, seed []byte) (r []byte) {
if _, err := kdf.h.Write([]byte{0x01}); err != nil {
panic(err)
}
if _, err := kdf.h.Write(label); err != nil {
panic(err)
}
if _, err := kdf.h.Write([]byte{0x00}); err != nil {
panic(err)
}
if _, err := kdf.h.Write(seed); err != nil {
panic(err)
}
if _, err := kdf.h.Write([]byte{0x01}); err != nil {
panic(err)
}
if _, err := kdf.h.Write([]byte{0x00}); err != nil {
panic(err)
}
r = kdf.h.Sum(dst)
kdf.h.Reset()
return r
}