检查域上的 SPF 记录的方法有哪些？
有一个网站，我可以手动使用 - http://www.mxtoolbox.com/SuperTool.aspx
我如何通过 ASP.NET 和 C# 来实现？基本上，如果域支持自己的邮件 Web 服务器，我想验证/检查域上的 SPF 记录。
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9722 次
8 回答
15
我有同样的问题，并设法找到两个三个解决方案：
解决nslookup方案
您可以通过在命令行中键入以下命令来获取 SPF：
nslookup -type=TXT <hostname>
您可以在 C# 中使用 自动执行此操作System.Diagonstics.Process，如本博文中所述。
DNS.NET 解析器项目
我找到了这篇关于 DNS 解析的CodeProject 文章。它带有演示项目。我运行该项目并得到以下结果stackexchange.com：
注意：确保QType字段设置为TXT，然后再按发送按钮
以黄色突出显示的部分代表 SPF 记录。我还没有深入研究代码以了解它是如何完成的，但这似乎是上述解决方案的一个很好的替代nslookup方案。
[更新] ARSoft.Tools.Net 项目
如果您只需要检查域是否支持邮件服务器，则可以使用ARSoft.Tools.Net库（也可作为NuGet 包提供）。
安装软件包后，我设法使用以下代码执行 SPF 检查：
var spfValidator = new ARSoft.Tools.Net.Spf.SpfValidator();
var mailIpAddress = IPAddress.Parse("X.X.X.X");
var domain = "example.com";
var senderAddress = "sender@example.com";
ARSoft.Tools.Net.Spf.SpfQualifier result =
spfValidator.CheckHost(mailIpAddress, domain, senderAddress);
于 2012-08-09T13:03:26.157 回答
6
尽管 .NET 对网络有很多支持，包括进行主机名到地址映射，但它缺乏查询 DNS 的通用方法。
但是，您可以使用 P/Invoke 直接调用DnsQuery 函数。API 有点麻烦，但根据您的要求创建正确的 P/Invoke 签名并非不可能。
SPF 记录在 DNS 中存储为 TXT 记录。您必须使用的相应结构是DNS_TXT_DATA 结构。如果您可以找到查询 MX 记录的示例，您可以重用代码并DNS_TYPE_TEXT用于查询类型并将数据解组到DNS_TXT_DATA结构中。
或者您可以只使用以下代码：
using System.ComponentModel;
using System.Runtime.InteropServices;
public String DnsGetTxtRecord(String name) {
const Int16 DNS_TYPE_TEXT = 0x0010;
const Int32 DNS_QUERY_STANDARD = 0x00000000;
const Int32 DNS_ERROR_RCODE_NAME_ERROR = 9003;
const Int32 DNS_INFO_NO_RECORDS = 9501;
var queryResultsSet = IntPtr.Zero;
try {
var dnsStatus = DnsQuery(
name,
DNS_TYPE_TEXT,
DNS_QUERY_STANDARD,
IntPtr.Zero,
ref queryResultsSet,
IntPtr.Zero
);
if (dnsStatus == DNS_ERROR_RCODE_NAME_ERROR || dnsStatus == DNS_INFO_NO_RECORDS)
return null;
if (dnsStatus != 0)
throw new Win32Exception(dnsStatus);
DnsRecordTxt dnsRecord;
for (var pointer = queryResultsSet; pointer != IntPtr.Zero; pointer = dnsRecord.pNext) {
dnsRecord = (DnsRecordTxt) Marshal.PtrToStructure(pointer, typeof(DnsRecordTxt));
if (dnsRecord.wType == DNS_TYPE_TEXT) {
var lines = new List<String>();
var stringArrayPointer = pointer
+ Marshal.OffsetOf(typeof(DnsRecordTxt), "pStringArray").ToInt32();
for (var i = 0; i < dnsRecord.dwStringCount; ++i) {
var stringPointer = (IntPtr) Marshal.PtrToStructure(stringArrayPointer, typeof(IntPtr));
lines.Add(Marshal.PtrToStringUni(stringPointer));
stringArrayPointer += IntPtr.Size;
}
return String.Join(Environment.NewLine, lines);
}
}
return null;
}
finally {
const Int32 DnsFreeRecordList = 1;
if (queryResultsSet != IntPtr.Zero)
DnsRecordListFree(queryResultsSet, DnsFreeRecordList);
}
}
[DllImport("Dnsapi.dll", EntryPoint = "DnsQuery_W", ExactSpelling = true, CharSet = CharSet.Unicode, SetLastError = true)]
static extern Int32 DnsQuery(String lpstrName, Int16 wType, Int32 options, IntPtr pExtra, ref IntPtr ppQueryResultsSet, IntPtr pReserved);
[DllImport("Dnsapi.dll")]
static extern void DnsRecordListFree(IntPtr pRecordList, Int32 freeType);
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
struct DnsRecordTxt {
public IntPtr pNext;
public String pName;
public Int16 wType;
public Int16 wDataLength;
public Int32 flags;
public Int32 dwTtl;
public Int32 dwReserved;
public Int32 dwStringCount;
public String pStringArray;
}
于 2012-08-09T13:08:21.847 回答
1
基于Martin Liversage 的回答，我添加了一些注释来解释发生了什么，并调整为返回多个记录（如果存在）。
我的示例还连接 TXT 记录中的多个字符串，而不是用换行符分隔。
if (dnsRecord.wType == DNS_TYPE_TEXT)考虑到约束在函数的参数中，我不知道该行是否真的有必要DnsQuery，但无论如何我还是从马丁的回答中保留了它。
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Text;
namespace Util
{
/// <summary>
/// Based on https://stackoverflow.com/a/11884174 (Martin Liversage)
/// </summary>
class DnsInterop
{
private const short DNS_TYPE_TEXT = 0x0010;
private const int DNS_QUERY_STANDARD = 0x00000000;
private const int DNS_ERROR_RCODE_NAME_ERROR = 9003;
private const int DNS_INFO_NO_RECORDS = 9501;
public static IEnumerable<string> GetTxtRecords(string domain)
{
var results = new List<string>();
var queryResultsSet = IntPtr.Zero;
DnsRecordTxt dnsRecord;
try
{
// get all text records
// pointer to results is returned in queryResultsSet
var dnsStatus = DnsQuery(
domain,
DNS_TYPE_TEXT,
DNS_QUERY_STANDARD,
IntPtr.Zero,
ref queryResultsSet,
IntPtr.Zero
);
// return null if no records or DNS lookup failed
if (dnsStatus == DNS_ERROR_RCODE_NAME_ERROR
|| dnsStatus == DNS_INFO_NO_RECORDS)
{
return null;
}
// throw an exception if other non success code
if (dnsStatus != 0)
throw new Win32Exception(dnsStatus);
// step through each result
for (
var pointer = queryResultsSet;
pointer != IntPtr.Zero;
pointer = dnsRecord.pNext)
{
dnsRecord = (DnsRecordTxt)
Marshal.PtrToStructure(pointer, typeof(DnsRecordTxt));
if (dnsRecord.wType == DNS_TYPE_TEXT)
{
var builder = new StringBuilder();
// pointer to array of pointers
// to each string that makes up the record
var stringArrayPointer = pointer + Marshal.OffsetOf(
typeof(DnsRecordTxt), "pStringArray").ToInt32();
// concatenate multiple strings in the case of long records
for (var i = 0; i < dnsRecord.dwStringCount; ++i)
{
var stringPointer = (IntPtr)Marshal.PtrToStructure(
stringArrayPointer, typeof(IntPtr));
builder.Append(Marshal.PtrToStringUni(stringPointer));
stringArrayPointer += IntPtr.Size;
}
results.Add(builder.ToString());
}
}
}
finally
{
if (queryResultsSet != IntPtr.Zero)
{
DnsRecordListFree(queryResultsSet,
(int)DNS_FREE_TYPE.DnsFreeRecordList);
}
}
return results;
}
[DllImport("Dnsapi.dll", EntryPoint = "DnsQuery_W",
ExactSpelling = true, CharSet = CharSet.Unicode,
SetLastError = true)]
static extern int DnsQuery(string lpstrName, short wType, int options,
IntPtr pExtra, ref IntPtr ppQueryResultsSet, IntPtr pReserved);
[DllImport("Dnsapi.dll")]
static extern void DnsRecordListFree(IntPtr pRecordList, int freeType);
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
struct DnsRecordTxt
{
public IntPtr pNext;
public string pName;
public short wType;
public short wDataLength;
public int flags;
public int dwTtl;
public int dwReserved;
public int dwStringCount;
public string pStringArray;
}
enum DNS_FREE_TYPE
{
DnsFreeFlat = 0,
DnsFreeRecordList = 1,
DnsFreeParsedMessageFields = 2
}
}
}
于 2016-07-04T09:23:43.643 回答
0
你基本上需要做一个 DNS 请求，询问域的 MX/SPF 记录。有一些在 C# 中执行此操作的示例。http://mailsystem.codeplex.com/上有一个库，其中有一个Validator类GetMxRecords可以执行此操作，您可能会发现它很有用
于 2012-08-07T17:01:24.980 回答
0
值得一提的是——MailBee 的 .NET 对象也支持这一点。我之所以这么说，是因为我们已经拥有了这个组件，当我发现这个好东西已经融入我们所拥有的东西时，我正要实现其他东西。
http://www.afterlogic.com/mailbee-net/docs/filter_spam_with_dns.html
于 2014-02-25T01:25:20.850 回答
0
基于 DnsDig 项目，我创建了一个 DLL，可用于任何 .net（vb、c#、forms、web.等）项目
https://devselz.com/software/devselz_dnsdig_dns-txt-etc-query-domain-register.zip
下载 DLL ，解压缩并添加为项目的引用（如果网站位于根/bin 文件夹中）：
DnsDig.dll
nunit.framework.dll
（共 126KB）
然后将此示例用作 ASP.Ne 网站（vb.net 代码）
Imports DnsDig
Imports Heijden.DNS
Partial Class lib_u_l_Default
Inherits System.Web.UI.Page
Public Resolver As Resolver
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
Resolver = New Resolver
Dim SW As New System.Diagnostics.Stopwatch
SW.Start()
Dim DNSResponse As Heijden.DNS.Response = Resolver.Query(Request.QueryString("d"), QType.SPF, QClass.ANY)
SW.Stop()
If DNSResponse.header.ANCOUNT > 0 Then
For Each answerRR As AnswerRR In DNSResponse.Answers
Response.Write("<br/>" & answerRR.ToString)
Next
End If
End Sub
End Class
结果： https ://yourwebsiteusingabovedlls.com/anyplacewhereabovecode/?d=goodyes.com
将会写
goodyes.com。3535 IN TXT“google-site-verification=IMw-tL0VWgMJbtcRgt_bu5UaVwpbNb94dvcOSObooa4”goodyes.com。第3535章
于 2021-07-11T05:22:56.627 回答
0
我们尝试使用@martin-liversage 的答案，但在数百个域上运行一段时间后，它在一些内存问题上失败了。（也许有一些无效/其他类型的 DNS 记录？）所以我研究了这个案例中使用的确切的 WINAPI 函数和结构，并相应地编辑了解决方案。
代码中包含指向 WINAPI 文档的链接。
所以这是我们改进的代码，即使在我们的例子中也可以 100% 工作：
public String GetSpfRecord(String domain)
{
// Definition of DNS params
const Int16 DNS_TYPE_TXT = 0x0010;
const Int32 DNS_QUERY_STANDARD = 0x00000001;
const Int32 DNS_ERROR_RCODE_NAME_ERROR = 9003;
const Int32 DNS_INFO_NO_RECORDS = 9501;
DnsRecordA dnsRecord;
var queryResultsSet = IntPtr.Zero;
try
{
var dnsStatus = DnsQuery(
domain,
DNS_TYPE_TXT,
DNS_QUERY_STANDARD,
IntPtr.Zero,
ref queryResultsSet,
IntPtr.Zero
);
if (dnsStatus == DNS_ERROR_RCODE_NAME_ERROR || dnsStatus == DNS_INFO_NO_RECORDS)
return null;
if (dnsStatus != 0)
throw new Win32Exception(dnsStatus);
for (IntPtr pointer = queryResultsSet; pointer != IntPtr.Zero; pointer = dnsRecord.pNext)
{
// Copies data from memory (size of DnsRecordA) from adress pointer to new alocated memory and creates instance of pointer to this place.
dnsRecord = (DnsRecordA)Marshal.PtrToStructure(pointer, typeof(DnsRecordA));
// pokud se jedná o typ TXT
if (dnsRecord.wType == DNS_TYPE_TXT)
{
// get pointer to informations in "Data" property (https://docs.microsoft.com/en-us/windows/win32/api/windns/ns-windns-dns_recorda)
var dataPointer = pointer + Marshal.SizeOf(typeof(DnsRecordA));
// Get the txtData
var txtData = (DNS_TXT_DATAA)Marshal.PtrToStructure(dataPointer, typeof(DNS_TXT_DATAA));
if (txtData.dwStringCount >= 1)
{
string line = Marshal.PtrToStringUni(txtData.pStringArray[0]);
// only if record starts with "v=spf" (Getting only SPF records)
// Getting only first (here is always maximum of 1 record) and returning whole line
if (line.StartsWith("v=spf") && string.IsNullOrEmpty(result))
{
return line;
}
}
}
}
// no SPF record - returning null
return null;
}
finally
{
const Int32 DnsFreeRecordList = 1;
// always release the memory alocated for list of dns records
if (queryResultsSet != IntPtr.Zero)
DnsRecordListFree(queryResultsSet, DnsFreeRecordList);
}
}
// https://docs.microsoft.com/en-us/windows/win32/api/windns/nf-windns-dnsquery_a
[DllImport("Dnsapi.dll", EntryPoint = "DnsQuery_W", ExactSpelling = true, CharSet = CharSet.Unicode, SetLastError = true)]
static extern Int32 DnsQuery(String lpstrName, Int16 wType, Int32 options, IntPtr pExtra, ref IntPtr ppQueryResultsSet, IntPtr pReserved);
// https://docs.microsoft.com/en-us/windows/win32/api/windns/nf-windns-dnsrecordlistfree
[DllImport("Dnsapi.dll")]
static extern void DnsRecordListFree(IntPtr pRecordList, Int32 freeType);
// https://docs.microsoft.com/en-us/windows/win32/api/windns/ns-windns-dns_recorda
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
struct DnsRecordA
{
public IntPtr pNext;
public String pName;
public Int16 wType;
public Int16 wDataLength;
public Int32 flags;
public Int32 dwTtl;
public Int32 dwReserved;
// Commented, because i'm getting this value dynamicaly (it can also be another structure type which might cause some problems)
//public DNS_TXT_DATA Data;
}
// https://docs.microsoft.com/en-us/windows/win32/api/windns/ns-windns-dns_txt_dataa
[StructLayout(LayoutKind.Sequential)]
struct DNS_TXT_DATAA
{
/// DWORD->unsigned int
public uint dwStringCount;
/// PSTR[1]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 1, ArraySubType = UnmanagedType.SysUInt)]
internal IntPtr[] pStringArray;
}
于 2020-09-02T07:50:51.927 回答
-1
有趣的是所有网站都有这个错误
SPF 不是 TXT
您可以有没有 SPF 的 txt 记录和没有 TXT 的 SPF，因此 TXT 查找不会显示 SPF
于 2014-07-09T10:55:59.293 回答