// Licensed to Elasticsearch B.V. under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Elasticsearch B.V. licenses this file to you under
// the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

//go:build !integration
// +build !integration

package tls

import (
	"testing"

	"github.com/stretchr/testify/assert"
)

func TestSni(t *testing.T) {

	// Single element

	buf := mkBuf(t, "000d"+ // 13 bytes
		"00"+ // type host
		"000a"+ // 10 byte string
		"656c61737469632e636f", // elastic.co
		15)
	r := parseSni(*buf)
	assert.NotNil(t, r)
	assert.Equal(t, []string{"elastic.co"}, r.([]string))

	// 3 elements

	buf = mkBuf(t, "0027"+ // 39 bytes
		"00"+ // type host
		"000a"+ // 10 byte string
		"656c61737469632e636f"+ // elastic.co
		"00"+ // type host
		"000b"+ // 11 byte string
		"6578616d706c652e6e6574"+ // example.net
		"00"+ // type host
		"0009"+ // 9 byte string
		"6c6f63616c686f7374", // localhost
		41)
	r = parseSni(*buf)
	assert.NotNil(t, r)
	assert.Equal(t, []string{"elastic.co", "example.net", "localhost"}, r.([]string))

	// Unknown entry type

	buf = mkBuf(t, "0027"+ // 39 bytes
		"00"+ // type host
		"000a"+ // 10 byte string
		"656c61737469632e636f"+ // elastic.co
		"01"+ // type ???
		"000b"+ // 11 byte string
		"6578616d706c652e6e6574"+ // example.net
		"00"+ // type host
		"0009"+ // 9 byte string
		"6c6f63616c686f7374", // localhost
		41)
	r = parseSni(*buf)
	assert.NotNil(t, r)
	assert.Equal(t, []string{"elastic.co", "localhost"}, r.([]string))

	// Truncated

	buf = mkBuf(t, "0400"+ // 1024 bytes
		"00"+ // type host
		"000a"+ // 10 byte string
		"656c61737469632e636f"+ // elastic.co
		"00"+ // type host
		"000b"+ // 11 byte string
		"6578616d706c652e6e6574"+ // example.net
		"00"+ // type host
		"0009"+ // 9 byte string
		"6c6f63616c686f7374", // localhost
		41)
	r = parseSni(*buf)
	assert.NotNil(t, r)
	assert.Equal(t, []string{"elastic.co", "example.net", "localhost"}, r.([]string))

	// Out of bounds

	buf = mkBuf(t, "0026"+ // 38 bytes
		"00"+ // type host
		"000a"+ // 10 byte string
		"656c61737469632e636f"+ // elastic.co
		"00"+ // type host
		"000b"+ // 11 byte string
		"6578616d706c652e6e6574"+ // example.net
		"00"+ // type host
		"0009"+ // 9 byte string
		"6c6f63616c686f7374", // localhost
		41)
	r = parseSni(*buf)
	assert.NotNil(t, r)
	assert.Equal(t, []string{"elastic.co", "example.net"}, r.([]string))

	// Out of bounds

	buf = mkBuf(t, "001c"+ // 28 bytes
		"00"+ // type host
		"000a"+ // 10 byte string
		"656c61737469632e636f"+ // elastic.co
		"00"+ // type host
		"000b"+ // 11 byte string
		"6578616d706c652e6e6574"+ // example.net
		"00"+ // type host
		"0009"+ // 9 byte string
		"6c6f63616c686f7374", // localhost
		41)
	r = parseSni(*buf)
	assert.NotNil(t, r)
	assert.Equal(t, []string{"elastic.co", "example.net"}, r.([]string))
}

func TestParseMaxFragmentLength(t *testing.T) {

	r := parseMaxFragmentLen(*mkBuf(t, "01", 1))
	assert.Equal(t, "2^9", r.(string))
	r = parseMaxFragmentLen(*mkBuf(t, "04", 1))
	assert.Equal(t, "2^12", r.(string))
	r = parseMaxFragmentLen(*mkBuf(t, "00", 1))
	assert.Equal(t, "(unknown:0)", r.(string))
	r = parseMaxFragmentLen(*mkBuf(t, "FF", 1))
	assert.Equal(t, "(unknown:255)", r.(string))
	r = parseMaxFragmentLen(*mkBuf(t, "FF", 2))
	assert.Nil(t, r)
}

func TestParseCertType(t *testing.T) {
	r := parseCertType(*mkBuf(t, "00", 1))
	assert.Equal(t, []string{"X.509"}, r.([]string))
	r = parseCertType(*mkBuf(t, "01", 1))
	assert.Equal(t, []string{"OpenPGP"}, r.([]string))
	r = parseCertType(*mkBuf(t, "02", 1))
	assert.Equal(t, []string{"RawPubKey"}, r.([]string))
	r = parseCertType(*mkBuf(t, "3c", 1))
	assert.Equal(t, []string{"(unknown:60)"}, r.([]string))
	r = parseCertType(*mkBuf(t, "03020100", 4))
	assert.Equal(t, []string{"RawPubKey", "OpenPGP", "X.509"}, r.([]string))
}

func TestParseSrp(t *testing.T) {
	r := parseSrp(*mkBuf(t, "04726f6f74", 5))
	assert.Equal(t, "root", r.(string))
	r = parseSrp(*mkBuf(t, "FF726f6f74", 5))
	assert.Nil(t, r)
}

func TestParseSupportedVersions(t *testing.T) {
	for _, testCase := range []struct {
		title    string
		data     string
		expected interface{}
	}{
		{
			title:    "negotiation",
			data:     "080304030303020301",
			expected: []string{"TLS 1.3", "TLS 1.2", "TLS 1.1", "TLS 1.0"},
		},
		{
			title:    "negotiation with GREASE",
			data:     "0c7a7a0304030303020301fafa",
			expected: []string{"TLS 1.3", "TLS 1.2", "TLS 1.1", "TLS 1.0"},
		},
		{
			title:    "selected TLS 1.3",
			data:     "0304",
			expected: "TLS 1.3",
		},
		{
			title:    "selected future version",
			data:     "0305",
			expected: "TLS 1.4",
		},
		{
			title: "empty error",
			data:  "00",
		},
		{
			title: "odd length error",
			data:  "0b7a7a0304030303020301FF",
		},
		{
			title: "out of bounds",
			data:  "FF",
		},
		{
			title: "out of bounds (2)",
			data:  "805a5a03040302",
		},
		{
			title:    "valid excess data",
			data:     "0403030304FFFFFFFFFFFFFF",
			expected: []string{"TLS 1.2", "TLS 1.3"},
		},
	} {
		t.Run(testCase.title, func(t *testing.T) {
			r := parseSupportedVersions(*mkBuf(t, testCase.data, len(testCase.data)/2))
			if testCase.expected == nil {
				assert.Nil(t, r, testCase.data)
				return
			}
			switch v := testCase.expected.(type) {
			case string:
				version, ok := r.(string)
				assert.True(t, ok)
				assert.Equal(t, v, version)
			case []string:
				list, ok := r.([]string)
				assert.True(t, ok)
				assert.Len(t, list, len(v))
				assert.Equal(t, v, list)
			default:
				assert.Fail(t, "wrong expected type", v)
			}
		})
	}
}
