// 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 (
	"bytes"
	"testing"

	"golang.org/x/crypto/hkdf"
)

func TestHKDF(t *testing.T) {
	t.Run("1", func(t *testing.T) {
		ikm := []byte{
			0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
			0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
			0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
		}
		salt := []byte{
			0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
			0x08, 0x09, 0x0a, 0x0b, 0x0c,
		}
		prk := hkdf.Extract(New, ikm, salt)
		if !bytes.Equal(prk, []byte{
			0x94, 0x7d, 0x3d, 0x99, 0x2e, 0xdc, 0x44, 0xe3,
			0x7b, 0x32, 0x72, 0x40, 0xf1, 0x5e, 0x62, 0x91,
			0x3c, 0x0b, 0x91, 0xcc, 0x3e, 0x21, 0x43, 0xff,
			0xe7, 0x72, 0x43, 0x6e, 0xc6, 0x3c, 0x99, 0xed,
		}) {
			t.Fatal("PRK differs")
		}
		info := []byte{0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9}
		okm := make([]byte, 42)
		if _, err := hkdf.Expand(New, prk, info).Read(okm); err != nil {
			t.Fatal("HKDF-Expand failed")
		}
		if !bytes.Equal(okm, []byte{
			0x35, 0xf8, 0xf8, 0x03, 0x7a, 0xad, 0xf7, 0xaf,
			0x3e, 0x4f, 0xc7, 0xbc, 0x8b, 0x93, 0xa9, 0x27,
			0xd6, 0x85, 0xd4, 0x2f, 0x66, 0x28, 0xf9, 0xe6,
			0x23, 0xc8, 0x5e, 0x19, 0x70, 0x09, 0x69, 0x2e,
			0xae, 0xb1, 0x0b, 0x25, 0x26, 0x71, 0x2a, 0x7b,
			0x49, 0xb7,
		}) {
			t.Fatal("OKM differs")
		}
	})
	t.Run("2", func(t *testing.T) {
		ikm := []byte{
			0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
			0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
			0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
			0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
			0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
			0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
			0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
			0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
			0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
			0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
		}
		salt := []byte{
			0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
			0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
			0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
			0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
			0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
			0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
			0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
			0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
			0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
			0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
		}
		prk := hkdf.Extract(New, ikm, salt)
		if !bytes.Equal(prk, []byte{
			0xa2, 0xff, 0xcd, 0x64, 0x44, 0x45, 0xef, 0x94,
			0x7e, 0x7e, 0xc9, 0xa8, 0x26, 0x89, 0x3d, 0x9a,
			0x91, 0xfc, 0xe2, 0x65, 0xb0, 0xc2, 0xa9, 0x59,
			0x6c, 0x59, 0xe1, 0x41, 0x53, 0x1d, 0x90, 0x77,
		}) {
			t.Fatal("PRK differs")
		}
		info := []byte{
			0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
			0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
			0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
			0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
			0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
			0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
			0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
			0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
			0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
			0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
		}
		okm := make([]byte, 82)
		if _, err := hkdf.Expand(New, prk, info).Read(okm); err != nil {
			t.Fatal("HKDF-Expand failed")
		}
		if !bytes.Equal(okm, []byte{
			0x28, 0x8c, 0x27, 0xff, 0xda, 0xf6, 0x4b, 0xe8,
			0x24, 0xde, 0x84, 0x93, 0x48, 0x9d, 0x03, 0x12,
			0x28, 0x07, 0xe9, 0x24, 0xaa, 0x6a, 0x09, 0x27,
			0x01, 0x16, 0x9d, 0x2f, 0x66, 0x38, 0xc9, 0xd5,
			0xc2, 0xbf, 0x09, 0xdb, 0x9f, 0xbe, 0x0b, 0x32,
			0x88, 0x59, 0x7b, 0x67, 0x1d, 0xaf, 0x17, 0xed,
			0x3e, 0x7d, 0xa5, 0x89, 0xdf, 0x69, 0xcc, 0x1d,
			0xdc, 0xd8, 0x26, 0x2c, 0x1c, 0x6b, 0xe1, 0x4b,
			0xc0, 0xb8, 0x5c, 0x4c, 0x2b, 0x24, 0xb6, 0xd8,
			0xb4, 0x38, 0x18, 0xa1, 0xa5, 0xb0, 0x67, 0x53,
			0xaf, 0x72,
		}) {
			t.Fatal("OKM differs")
		}
	})
	t.Run("3", func(t *testing.T) {
		ikm := []byte{
			0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
			0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
			0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
		}
		salt := []byte{}
		prk := hkdf.Extract(New, ikm, salt)
		if !bytes.Equal(prk, []byte{
			0x1f, 0xfc, 0x6d, 0x2b, 0xf9, 0x59, 0x4d, 0xfd,
			0xf7, 0x75, 0xc2, 0xc1, 0x8f, 0xa3, 0xae, 0xcc,
			0x92, 0xb6, 0xf9, 0xbc, 0x5c, 0xff, 0x0e, 0x08,
			0x6f, 0x34, 0x0f, 0xab, 0x33, 0x6d, 0x86, 0x5f,
		}) {
			t.Fatal("PRK differs")
		}
		info := []byte{}
		okm := make([]byte, 42)
		if _, err := hkdf.Expand(New, prk, info).Read(okm); err != nil {
			t.Fatal("HKDF-Expand failed")
		}
		if !bytes.Equal(okm, []byte{
			0x6a, 0xad, 0xb1, 0xa6, 0x48, 0x96, 0x2f, 0x0d,
			0x96, 0x19, 0xcc, 0xdb, 0xf9, 0xd9, 0x2d, 0xc3,
			0x54, 0x79, 0x73, 0x73, 0x3b, 0xc4, 0x06, 0x1d,
			0x9f, 0xa5, 0x3e, 0xa8, 0x2a, 0x17, 0x35, 0xd7,
			0xf3, 0xa4, 0x84, 0x6c, 0x76, 0xf9, 0x94, 0xb5,
			0xdd, 0x03,
		}) {
			t.Fatal("OKM differs")
		}
	})
}