微信验证码提取基础实现检查点

backend/hooks/wechat_push/verification_code.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"bytes"
+	"regexp"
+	"strings"
+
+	"git.pcux.cn/xuans/Smail/dto/parsemail"
+	"golang.org/x/net/html"
+)
+
+const maxWeChatVerificationScanBytes = 64 << 10
+
+const weChatVerificationKeyword = `(?:验证码|校验码|动态码|认证码|一次性(?:密码|口令)|verification[\s-]*code|security[\s-]*code|authentication[\s-]*code|one[\s-]*time[\s-]*(?:password|code)|passcode|\botp\b)`
+
+var weChatVerificationPatterns = []*regexp.Regexp{
+	regexp.MustCompile(`(?i)` + weChatVerificationKeyword + `(?:[[:space:][:punct:]：，。！【】（）]|是|为|is|equals|如下|your|please|use){0,20}\b([A-Z0-9]{4,8})\b`),
+	regexp.MustCompile(`(?i)\b([A-Z0-9]{4,8})\b(?:[[:space:][:punct:]：，。！【】（）]|是|为|is|your|您的){0,20}` + weChatVerificationKeyword),
+}
+
+func extractWeChatVerificationCode(email *parsemail.Email) (string, bool) {
+	if email == nil {
+		return "", false
+	}
+	// 分别检查标题和各正文，避免跨字段拼接出不存在的验证码。
+	if code, ok := findWeChatVerificationCode(truncateWeChatText(email.Subject, maxWeChatVerificationScanBytes)); ok {
+		return code, true
+	}
+	text := email.Text[:min(len(email.Text), maxWeChatVerificationScanBytes)]
+	if code, ok := findWeChatVerificationCode(string(text)); ok {
+		return code, true
+	}
+	return findWeChatVerificationCode(weChatHTMLNotificationText(email.HTML))
+}
+
+func findWeChatVerificationCode(content string) (string, bool) {
+	for _, pattern := range weChatVerificationPatterns {
+		for _, match := range pattern.FindAllStringSubmatch(content, -1) {
+			code := match[1]
+			// 排除普通英文单词，只识别至少含一个数字的四至八位字母数字组合。
+			if strings.ContainsAny(code, "0123456789") {
+				return code, true
+			}
+		}
+	}
+	return "", false
+}
+
+func weChatHTMLNotificationText(content []byte) string {
+	// 限制原始输入，避免大邮件在通知提取阶段产生无界扫描和额外分配。
+	content = content[:min(len(content), maxWeChatVerificationScanBytes)]
+	tokenizer := html.NewTokenizer(bytes.NewReader(content))
+	var text strings.Builder
+	hiddenDepth := 0
+	for {
+		switch tokenizer.Next() {
+		case html.ErrorToken:
+			return text.String()
+		case html.StartTagToken:
+			name, _ := tokenizer.TagName()
+			if weChatHiddenHTMLTag(string(name)) {
+				hiddenDepth++
+			}
+		case html.EndTagToken:
+			name, _ := tokenizer.TagName()
+			if hiddenDepth > 0 && weChatHiddenHTMLTag(string(name)) {
+				hiddenDepth--
+			}
+		case html.TextToken:
+			if hiddenDepth == 0 {
+				// 分词器负责解码实体；不读取属性、注释、脚本及样式中的内容。
+				text.Write(tokenizer.Text())
+				text.WriteByte(' ')
+			}
+		}
+	}
+}
+
+func weChatHiddenHTMLTag(name string) bool {
+	switch name {
+	case "head", "script", "style", "template":
+		return true
+	default:
+		return false
+	}
+}

backend/hooks/wechat_push/wechat_push.go

@@ -299,6 +299,9 @@ func buildWeChatMessage(email *parsemail.Email) string {
 	if email == nil {
 		return ""
 	}
+	if code, ok := extractWeChatVerificationCode(email); ok {
+		return "验证码：" + code
+	}
 	const prefix = "<<"
 	const separator = ">>  "
 	subjectLimit := maxWeChatMessageBytes - len(prefix) - len(separator)