118 lines
2.8 KiB
Go
118 lines
2.8 KiB
Go
// Licensed to Elasticsearch B.V. under one or more contributor
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// license agreements. See the NOTICE file distributed with
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// this work for additional information regarding copyright
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// ownership. Elasticsearch B.V. licenses this file to you under
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// the Apache License, Version 2.0 (the "License"); you may
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// not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing,
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// software distributed under the License is distributed on an
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// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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// KIND, either express or implied. See the License for the
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// specific language governing permissions and limitations
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// under the License.
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package tls
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import (
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"fmt"
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"github.com/elastic/beats/libbeat/common/streambuf"
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)
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type bufferView struct {
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buf *streambuf.Buffer
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base, limit int
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}
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func newBufferView(buf *streambuf.Buffer, pos int, length int) *bufferView {
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return &bufferView{buf, pos, pos + length}
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}
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func (r bufferView) read8(pos int, dest *uint8) bool {
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offset := pos + r.base
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if offset+1 > r.limit {
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return false
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}
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val, err := r.buf.ReadNetUint8At(offset)
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*dest = val
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return err == nil
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}
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func (r bufferView) read16Net(pos int, dest *uint16) bool {
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offset := pos + r.base
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if offset+2 > r.limit {
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return false
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}
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val, err := r.buf.ReadNetUint16At(offset)
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*dest = val
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return err == nil
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}
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func (r bufferView) read24Net(pos int, dest *uint32) bool {
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offset := pos + r.base
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if offset+3 > r.limit {
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return false
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}
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val8, err := r.buf.ReadNetUint8At(offset)
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if err != nil {
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return false
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}
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val16, err := r.buf.ReadNetUint16At(offset + 1)
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if err != nil {
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return false
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}
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*dest = uint32(val16) | (uint32(val8) << 16)
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return true
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}
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func (r bufferView) read32Net(pos int, dest *uint32) bool {
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offset := pos + r.base
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if offset+4 > r.limit {
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return false
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}
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val, err := r.buf.ReadNetUint32At(offset)
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*dest = val
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return err == nil
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}
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func (r bufferView) readString(pos int, len int, dest *string) bool {
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if slice := r.readBytes(pos, len); slice != nil {
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*dest = string(slice)
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return true
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}
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return false
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}
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func (r bufferView) readBytes(pos int, length int) []byte {
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offset := pos + r.base
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lim := offset + length
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if lim > r.limit {
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return nil
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}
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bytes := r.buf.Bytes()
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if lim <= len(bytes) {
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return r.buf.Bytes()[offset:lim]
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}
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return nil
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}
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func (r bufferView) subview(start, length int) bufferView {
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if 0 <= start && 0 <= length && start+length <= r.limit {
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return bufferView{
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base: r.base + start,
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limit: r.base + start + length,
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buf: r.buf,
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}
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}
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panic(fmt.Sprintf("invalid buffer view requested start:%d len:%d limit:%d",
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start, length, r.limit))
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}
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func (r bufferView) length() int {
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return r.limit - r.base
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}
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