mirror of
https://gitee.com/samwaf/SamWaf.git
synced 2025-12-06 06:58:54 +08:00
288 lines
8.9 KiB
Go
288 lines
8.9 KiB
Go
package wafenginecore
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import (
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"SamWaf/common/zlog"
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"SamWaf/utils"
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"bufio"
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"bytes"
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"compress/flate"
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"compress/gzip"
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"errors"
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"fmt"
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"github.com/andybalholm/brotli"
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"golang.org/x/net/html/charset"
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"golang.org/x/text/encoding"
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"golang.org/x/text/encoding/simplifiedchinese"
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"golang.org/x/text/encoding/unicode"
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"golang.org/x/text/transform"
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"io"
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"net/http"
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"strings"
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)
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// 返回内容前依据情况进行返回压缩数据
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func (waf *WafEngine) compressContent(res *http.Response, isStaticAssist bool, inputBytes []byte, encodeType string) (respBytes []byte, err error) {
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// 如果是静态资源响应或资源类型请求，直接返回原始内容
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if isStaticAssist {
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return inputBytes, errors.New("静态资源或资源类型请求，跳过编码转换")
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}
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// 首先检查Content-Type头中是否明确指定了字符集
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contentType := res.Header.Get("Content-Type")
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var encodedBytes []byte = inputBytes
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charsetName := encodeType
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// 如果Content-Type中指定了字符集，需要将UTF-8编码的内容转换回原始编码
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if charsetName == "" && strings.Contains(contentType, "charset=") {
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parts := strings.Split(contentType, ";")
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for _, part := range parts {
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part = strings.TrimSpace(part)
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if strings.HasPrefix(part, "charset=") {
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charsetName = strings.TrimPrefix(part, "charset=")
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charsetName = strings.Trim(charsetName, `"'`)
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break
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}
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}
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}
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// 根据字符集进行编码转换
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if charsetName != "" && !strings.EqualFold(charsetName, "utf-8") && !strings.EqualFold(charsetName, "utf8") {
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switch strings.ToLower(charsetName) {
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case "gbk", "gb2312":
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// 将UTF-8转换为GBK
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encoder := simplifiedchinese.GBK.NewEncoder()
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encodedBytes, err = encoder.Bytes(inputBytes)
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if err != nil {
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zlog.Warn("编码转换失败(UTF-8 -> GBK): %v", err)
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// 转换失败时使用原始UTF-8内容
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encodedBytes = inputBytes
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}
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// 可以根据需要添加其他编码的支持
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default:
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zlog.Debug("不支持的字符集编码转换: %s，保持UTF-8编码", charsetName)
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}
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}
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// 根据Content-Encoding进行压缩
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switch res.Header.Get("Content-Encoding") {
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case "gzip":
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respBytes, err = utils.GZipEncode(encodedBytes)
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case "deflate":
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respBytes, err = utils.DeflateEncode(encodedBytes)
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case "br":
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respBytes, err = utils.BrotliEncode(encodedBytes)
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default:
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respBytes = encodedBytes
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}
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return
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}
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// 获取原始内容
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func (waf *WafEngine) getOrgContent(resp *http.Response, isStaticAssist bool, defaultEncoding string) (cntBytes []byte, encodeType string, err error) {
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bodyBytes, err := io.ReadAll(resp.Body)
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if err != nil {
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return bodyBytes, "", fmt.Errorf("读取原始响应体失败: %v", err)
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}
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charsetNameFinal := ""
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// 重新设置响应体，以便后续处理
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resp.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))
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// 如果是静态资源响应或资源类型请求，直接返回原始内容
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if isStaticAssist {
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return bodyBytes, "", errors.New("静态资源或资源类型请求，跳过编码转换")
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}
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// 根据内容编码处理压缩
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var bodyReader io.Reader
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switch resp.Header.Get("Content-Encoding") {
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case "gzip":
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gzipReader, gzipErr := gzip.NewReader(resp.Body)
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if gzipErr != nil {
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zlog.Warn("gzip解压失败: %v", gzipErr)
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// 失败时返回错误
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return bodyBytes, "", fmt.Errorf("gzip解压失败: %v", gzipErr)
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}
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bodyReader = gzipReader
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defer gzipReader.Close()
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case "deflate":
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deflateReader := flate.NewReader(resp.Body)
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bodyReader = deflateReader
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defer deflateReader.Close()
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case "br":
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brotliReader := brotli.NewReader(resp.Body)
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bodyReader = brotliReader
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default:
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bodyReader = resp.Body
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}
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// 创建缓冲读取器
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bufReader := bufio.NewReader(bodyReader)
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// 首先检查Content-Type头中是否明确指定了字符集
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contentType := resp.Header.Get("Content-Type")
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var currentEncoding encoding.Encoding
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if defaultEncoding != "" {
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switch strings.ToLower(defaultEncoding) {
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case "utf-8", "utf8":
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currentEncoding = unicode.UTF8
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charsetNameFinal = "utf-8"
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break
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case "gbk", "gb2312":
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currentEncoding = simplifiedchinese.GBK
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charsetNameFinal = "gbk"
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break
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default:
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}
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} else if strings.Contains(contentType, "charset=") {
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charsetName := ""
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parts := strings.Split(contentType, ";")
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for _, part := range parts {
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part = strings.TrimSpace(part)
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if strings.HasPrefix(part, "charset=") {
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charsetName = strings.TrimPrefix(part, "charset=")
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charsetName = strings.Trim(charsetName, `"'`)
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break
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}
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}
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// 如果找到了字符集
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if charsetName != "" {
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zlog.Debug("从Content-Type中检测到字符集: %s", charsetName)
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switch strings.ToLower(charsetName) {
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case "utf-8", "utf8":
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currentEncoding = unicode.UTF8
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charsetNameFinal = "utf-8"
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break
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case "gbk", "gb2312":
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currentEncoding = simplifiedchinese.GBK
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charsetNameFinal = "gbk"
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break
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default:
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currentEncoding = nil // 使用自动检测
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}
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}
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}
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// 如果没有从Content-Type中获取到编码或获取的编码不支持，则使用自动检测
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if currentEncoding == nil {
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// 增加检测字节数到1024，提高准确性
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peekBytes, peekErr := bufReader.Peek(1024)
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if peekErr != nil && peekErr != io.EOF {
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return bodyBytes, "", errors.New(fmt.Sprintf("编码检测错误，Peek失败: %v", peekErr))
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} else {
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// 先尝试用系统自带的自动检测
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detectedEncoding, name, certain := charset.DetermineEncoding(peekBytes, contentType)
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if !certain {
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// 自动检测不确定时，尝试从HTML头部meta标签或DOCTYPE中提取编码
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htmlHead := string(peekBytes)
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metaCharset := ""
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// 1. 检查meta标签
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metaIdx := strings.Index(strings.ToLower(htmlHead), "charset=")
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if metaIdx != -1 {
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// 提取charset=后面的内容
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substr := htmlHead[metaIdx+8:]
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// 只取等号后面第一个非字母数字下划线的内容
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for i, c := range substr {
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if !(c == '-' || c == '_' || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9')) {
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metaCharset = substr[:i]
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break
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}
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}
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if metaCharset == "" {
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metaCharset = substr
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}
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metaCharset = strings.Trim(metaCharset, "\"' />")
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}
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// 2. 检查DOCTYPE声明
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if metaCharset == "" && strings.Contains(htmlHead, "xhtml1-transitional.dtd") {
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// XHTML 1.0 通常默认utf-8或iso-8859-1
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metaCharset = "utf-8"
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}
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if metaCharset != "" {
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zlog.Debug("通过HTML头部meta/doctype辅助检测到字符集: %s", metaCharset)
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switch strings.ToLower(metaCharset) {
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case "utf-8", "utf8":
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currentEncoding = unicode.UTF8
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charsetNameFinal = "utf-8"
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break
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case "gbk", "gb2312":
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currentEncoding = simplifiedchinese.GBK
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charsetNameFinal = "gbk"
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break
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default:
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zlog.Debug("meta标签检测到未知字符集: %s，保持UTF-8", metaCharset)
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return bodyBytes, "", errors.New(fmt.Sprintf("编码检测不确定，且未能从HTML头部meta/doctype提取到编码"))
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}
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} else {
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return bodyBytes, "", errors.New(fmt.Sprintf("编码检测不确定，且未能从HTML头部meta/doctype提取到编码"))
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}
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} else {
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zlog.Debug("编码检测确定为: %s", name)
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currentEncoding = detectedEncoding
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}
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}
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}
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// 使用检测到的编码创建转换读取器
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reader := transform.NewReader(bufReader, currentEncoding.NewDecoder())
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// 读取全部内容
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resBodyBytes, readErr := io.ReadAll(reader)
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if readErr != nil {
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zlog.Warn("读取响应体失败: %v", readErr)
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return bodyBytes, "", fmt.Errorf("读取响应体失败: %v", readErr)
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}
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return resBodyBytes, charsetNameFinal, nil
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}
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// 处理请求的Content-Encoding解压
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func (waf *WafEngine) decompressRequestContent(req *http.Request) ([]byte, error) {
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if req.Body == nil || req.Body == http.NoBody {
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return nil, nil
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}
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// 读取原始请求体
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bodyBytes, err := io.ReadAll(req.Body)
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if err != nil {
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return nil, fmt.Errorf("读取请求体失败: %v", err)
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}
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// 重新设置请求体
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req.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))
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// 根据Content-Encoding进行解压
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var bodyReader io.Reader
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switch req.Header.Get("Content-Encoding") {
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case "gzip":
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gzipReader, gzipErr := gzip.NewReader(bytes.NewReader(bodyBytes))
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if gzipErr != nil {
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zlog.Warn("请求gzip解压失败: %v", gzipErr)
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return bodyBytes, fmt.Errorf("请求gzip解压失败: %v", gzipErr)
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}
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bodyReader = gzipReader
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defer gzipReader.Close()
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case "deflate":
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deflateReader := flate.NewReader(bytes.NewReader(bodyBytes))
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bodyReader = deflateReader
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defer deflateReader.Close()
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case "br":
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brotliReader := brotli.NewReader(bytes.NewReader(bodyBytes))
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bodyReader = brotliReader
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default:
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// 没有压缩或不支持的压缩格式，直接返回原始内容
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return bodyBytes, nil
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}
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// 读取解压后的内容
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decompressedBytes, readErr := io.ReadAll(bodyReader)
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if readErr != nil {
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zlog.Warn("读取解压后的请求体失败: %v", readErr)
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return bodyBytes, fmt.Errorf("读取解压后的请求体失败: %v", readErr)
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}
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return decompressedBytes, nil
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}
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