与支持TLS 1.2的服务器通信的默认安全协议是什么?.NET默认情况下会选择服务器端支持的最高安全协议吗?或者我必须显式地添加这行代码:
System.Net.ServicePointManager.SecurityProtocol =
SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
除了代码更改之外，是否有方法更改此默认值?
最后，.NET 4.0是否只支持TLS 1.0?例如，我必须将客户端项目升级到4.5以支持TLS 1.2。
我的动机是在客户端删除对SSLv3的支持，即使服务器支持它(我已经有一个powershell脚本在机器注册表中禁用它)，并支持服务器支持的最高TLS协议。
更新:
查看。net 4.0中的ServicePointManager类，我没有看到TLS 1.0和1.1的枚举值。在这两个。net 4.0/4.5中，默认为SecurityProtocolType.Tls|SecurityProtocolType.Ssl3。希望在注册表中禁用SSLv3不会破坏这个默认值。
然而，我决定将所有应用程序升级到。net 4.5，并显式地添加SecurityProtocolType。Tls |安全协议类型。Tls11 | SecurityProtocolType.Tls12;总之，所有应用程序的引导代码。
这将使对各种api和服务的出站请求不降级到SSLv3，并且应该选择最高级别的TLS。
这种方法听起来合理还是过份?我有很多应用程序要更新，我想在未来证明它们，因为我听说在不久的将来，一些提供商可能会弃用TLS 1.0。
作为一个向api发出出站请求的客户端，在注册表中禁用SSL3会对.NET框架产生影响吗?我看到默认情况下，TLS 1.1和1.2没有启用，我们必须通过注册表启用它吗?是http://support.microsoft.com/kb/245030。
经过一番研究，我相信注册表设置不会有任何影响，因为它们适用于IIS(服务器子密钥)和浏览器(客户端子密钥)。
对不起，这篇文章变成了多个问题，然后是“可能”的答案。
. net 4.0/4.5中默认的System.Net.ServicePointManager.SecurityProtocol是SecurityProtocolType.Tls|SecurityProtocolType.Ssl3。
.NET 4.0支持TLS 1.0， .NET 4.5支持TLS 1.2
然而，如果在相同的环境中安装了。net 4.5，针对. net 4.0的应用程序仍然可以支持TLS 1.2。
我通过观察fiddler4在流量中设置的正确安全协议，并在.NET 4.0项目中手动设置枚举值来验证这一点:
ServicePointManager.SecurityProtocol = (SecurityProtocolType)192 |
(SecurityProtocolType)768 | (SecurityProtocolType)3072;
参考:
namespace System.Net
{
[System.Flags]
public enum SecurityProtocolType
{
Ssl3 = 48,
Tls = 192,
Tls11 = 768,
Tls12 = 3072,
}
}
如果你试图在安装了。net 4.0的环境中进行黑客攻击，你会得到异常:
未处理异常:系统。NotSupportedException:请求的安全协议不支持。
在System.Net.ServicePointManager。set_SecurityProtocol (SecurityProtocolType v
价值)
然而，我不建议这个“黑客”，因为未来的补丁等可能会打破它
因此，我决定移除对SSLv3的支持的最佳途径是:
将所有应用程序升级到。net 4.5
在boostrapping代码中添加以下代码来覆盖默认值并在未来证明它:
System.Net.ServicePointManager.SecurityProtocol =
SecurityProtocolType。Tls |安全协议类型。Tls11 | SecurityProtocolType.Tls12;
*如果这个黑客是错误的，有人纠正我，但初步测试我看到它工作
一些在其他答案上留下评论的人注意到，将System.Net.ServicePointManager.SecurityProtocol设置为特定的值意味着你的应用程序将无法利用未来的TLS版本，这些TLS版本在未来的。net更新中可能成为默认值。与其指定一个固定的协议列表，不如执行以下操作:
对于。net 4.7或更高版本，不要设置System.Net.ServicePointManager.SecurityProtocol。默认值(SecurityProtocolType.SystemDefault)将允许操作系统使用它知道的和已配置的任何版本，包括在应用程序创建时可能不存在的任何新版本。
对于。net Framework的早期版本，您可以打开或关闭您所了解和关心的协议，而让其他协议保持原样。
启用TLS 1.1和TLS 1.2而不影响其他协议:
System.Net.ServicePointManager.SecurityProtocol |=
SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
注意使用|=来打开这些标志而不关闭其他标志。
关闭SSL3而不影响其他协议。
System.Net.ServicePointManager.SecurityProtocol &= ~SecurityProtocolType.Ssl3;
当我的客户将TLS从1.0升级到1.2时，我遇到了这个问题。
我的应用程序使用。net framework 3.5和运行在服务器上。所以我用这种方法来解决它:
修复程序
在调用HttpWebRequest.GetResponse()之前添加以下命令:
ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolTypeExtensions.Tls11 | SecurityProtocolTypeExtensions.Tls12;
通过添加2个新类扩展2个dll: System。网络和系统。安全性。身份验证
namespace System.Net
{
using System.Security.Authentication;
public static class SecurityProtocolTypeExtensions
{
public const SecurityProtocolType Tls12 = (SecurityProtocolType)SslProtocolsExtensions.Tls12;
public const SecurityProtocolType Tls11 = (SecurityProtocolType)SslProtocolsExtensions.Tls11;
public const SecurityProtocolType SystemDefault = (SecurityProtocolType)0;
}
}
namespace System.Security.Authentication
{
public static class SslProtocolsExtensions
{
public const SslProtocols Tls12 = (SslProtocols)0x00000C00;
public const SslProtocols Tls11 = (SslProtocols)0x00000300;
}
}
更新Microsoft批处理
批量下载:
windows 2008 R2操作系统:windows6.1-kb3154518-x64.msu
windows 2012
R2: windows8.1-kb3154520-x64.msu
下载批量和更多细节，你可以在这里看到:
https://support.microsoft.com/en-us/help/3154518/support-for-tls-system-default-versions-included-in-the-.net-framework-3.5.1-on-windows-7-sp1-and-server-2008-r2-sp1
以下代码将:
打印启用的协议
打印可用协议
如果平台支持TLS1.2，则启用TLS1.2，如果一开始没有启用TLS1.2
如果启用了SSL3，则禁用它
打印最终结果
常量:
48是SSL3
192是TLS1
768是TLS1.1
3072是TLS1.2
其他协议不受影响。这使得它与未来的协议(Tls1.3等)兼容。
Code
// print initial status
Console.WriteLine("Runtime: " + System.Diagnostics.FileVersionInfo.GetVersionInfo(typeof(int).Assembly.Location).ProductVersion);
Console.WriteLine("Enabled protocols: " + ServicePointManager.SecurityProtocol);
Console.WriteLine("Available protocols: ");
Boolean platformSupportsTls12 = false;
foreach (SecurityProtocolType protocol in Enum.GetValues(typeof(SecurityProtocolType))) {
Console.WriteLine(protocol.GetHashCode());
if (protocol.GetHashCode() == 3072){
platformSupportsTls12 = true;
}
}
Console.WriteLine("Is Tls12 enabled: " + ServicePointManager.SecurityProtocol.HasFlag((SecurityProtocolType)3072));
// enable Tls12, if possible
if (!ServicePointManager.SecurityProtocol.HasFlag((SecurityProtocolType)3072)){
if (platformSupportsTls12){
Console.WriteLine("Platform supports Tls12, but it is not enabled. Enabling it now.");
ServicePointManager.SecurityProtocol |= (SecurityProtocolType)3072;
} else {
Console.WriteLine("Platform does not supports Tls12.");
}
}
// disable ssl3
if (ServicePointManager.SecurityProtocol.HasFlag(SecurityProtocolType.Ssl3)) {
Console.WriteLine("Ssl3SSL3 is enabled. Disabling it now.");
// disable SSL3. Has no negative impact if SSL3 is already disabled. The enclosing "if" if just for illustration.
System.Net.ServicePointManager.SecurityProtocol &= ~SecurityProtocolType.Ssl3;
}
Console.WriteLine("Enabled protocols: " + ServicePointManager.SecurityProtocol);
输出
Runtime: 4.7.2114.0
Enabled protocols: Ssl3, Tls
Available protocols:
0
48
192
768
3072
Is Tls12 enabled: False
Platform supports Tls12, but it is not enabled. Enabling it now.
Ssl3 is enabled. Disabling it now.
Enabled protocols: Tls, Tls12
I'm running under .NET 4.5.2, and I wasn't happy with any of these answers. As I'm talking to a system which supports TLS 1.2, and seeing as SSL3, TLS 1.0, and TLS 1.1 are all broken and unsafe for use, I don't want to enable these protocols. Under .NET 4.5.2, the SSL3 and TLS 1.0 protocols are both enabled by default, which I can see in code by inspecting ServicePointManager.SecurityProtocol. Under .NET 4.7, there's the new SystemDefault protocol mode which explicitly hands over selection of the protocol to the OS, where I believe relying on registry or other system configuration settings would be appropriate. That doesn't seem to be supported under .NET 4.5.2 however. In the interests of writing forwards-compatible code, that will keep making the right decisions even when TLS 1.2 is inevitably broken in the future, or when I upgrade to .NET 4.7+ and hand over more responsibility for selecting an appropriate protocol to the OS, I adopted the following code:
SecurityProtocolType securityProtocols = ServicePointManager.SecurityProtocol;
if (securityProtocols.HasFlag(SecurityProtocolType.Ssl3) || securityProtocols.HasFlag(SecurityProtocolType.Tls) || securityProtocols.HasFlag(SecurityProtocolType.Tls11))
{
securityProtocols &= ~(SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11);
if (securityProtocols == 0)
{
securityProtocols |= SecurityProtocolType.Tls12;
}
ServicePointManager.SecurityProtocol = securityProtocols;
}
This code will detect when a known insecure protocol is enabled, and in this case, we'll remove these insecure protocols. If no other explicit protocols remain, we'll then force enable TLS 1.2, as the only known secure protocol supported by .NET at this point in time. This code is forwards compatible, as it will take into consideration new protocol types it doesn't know about being added in the future, and it will also play nice with the new SystemDefault state in .NET 4.7, meaning I won't have to re-visit this code in the future. I'd strongly recommend adopting an approach like this, rather than hard-coding any particular security protocol states unconditionally, otherwise you'll have to recompile and replace your client with a new version in order to upgrade to a new security protocol when TLS 1.2 is inevitably broken, or more likely you'll have to leave the existing insecure protocols turned on for years on your server, making your organisation a target for attacks.
微软最近发布了相关的最佳实践。https://learn.microsoft.com/en-us/dotnet/framework/network-programming/tls
总结
目标。net Framework 4.7，删除任何设置安全协议的代码，这样操作系统将确保您使用最安全的解决方案。
注意:您还需要确保您的操作系统支持并启用TLS的最新版本。
OS TLS 1.2 support
Windows 10 \_ Supported, and enabled by default.
Windows Server 2016 /
Windows 8.1 \_ Supported, and enabled by default.
Windows Server 2012 R2 /
Windows 8.0 \_ Supported, and enabled by default.
Windows Server 2012 /
Windows 7 SP1 \_ Supported, but not enabled by default*.
Windows Server 2008 R2 SP1 /
Windows Server 2008 - Support for TLS 1.2 and TLS 1.1 requires an update. See Update to add support for TLS 1.1 and TLS 1.2 in Windows Server 2008 SP2.
Windows Vista - Not supported.
* To enable TLS1.2 via the registry see https://learn.microsoft.com/en-us/windows-server/security/tls/tls-registry-settings#tls-12
Path: HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server
Property: Enabled
Type: REG_DWORD
Value: 1
Property: DisabledByDefault
Type: REG_DWORD
Value: 0
Path: HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client
Property: Enabled
Type: REG_DWORD
Value: 1
Property: DisabledByDefault
Type: REG_DWORD
Value: 0
有关更多信息和旧框架，请参考MS链接。
有两种可能的情况，
如果你的应用程序运行在。net framework 4.5或更低版本上，你可以很容易地将新代码部署到产品中，那么你可以使用下面的解决方案。
你可以在调用api之前添加下面的代码行，
ServicePointManager。SecurityProtocol = SecurityProtocolType.Tls12;// .net 4.5
如果您无法部署新代码，而希望使用生产环境中存在的相同代码进行解析，那么您有两个选择。
方案一:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319]
"SchUseStrongCrypto"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\.NETFramework\v4.0.30319]
"SchUseStrongCrypto"=dword:00000001
然后创建一个扩展名为.reg的文件并安装。
注意:此设置将应用于注册表级别，并适用于该机器上的所有应用程序，如果您希望仅限制为单个应用程序，则可以使用选项2
选项2:这可以通过更改配置文件中的一些配置设置来完成。
您可以在配置文件中添加其中任何一个。
<runtime>
<AppContextSwitchOverrides value="Switch.System.Net.DontEnableSchUseStrongCrypto=false"/>
</runtime>
or
<runtime>
<AppContextSwitchOverrides value="Switch.System.Net.DontEnableSystemDefaultTlsVersions=false"
</runtime>
