blocks|key|6063686|text|Outlook对象模型始终尝试将签名和加密的邮件表示为常规MailItem对象。MessageClass属性将返回"IPM.Note"“。它甚至可以从MailItem.MAPIOBJECT属性返回一个伪IMessage对象。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|6063687|如果您使用的是扩展的MAPI，您可以读取PR_MESSAGE_CLASS属性并检查它的值是否对应于一个签名/加密的消息类(例如"IPM.Note.SMIME.MultipartSigned")。如果要从MailItem.MAPIOBJECT属性中检索IMessage对象，请确保将其解包。|6063688|您还可以使用Redemption和它的RDOEncryptedMessage对象-它允许使用RDOEncryptedMessage.GetDecryptedMessage消息解密加密消息以及访问证书属性。|6063689|entityMap|0|LINK|mutability|MUTABLE|url|http://www.dimastr.com/redemption/|1|http://www.dimastr.com/redemption/rdoencryptedmessage.htm^0|T|8|14|C|1M|9|23|J|2T|8|0|K|G|1R|W|2T|J|3H|8|0|1A|13|6|A|0|J|J|1|0^^$0|@$1|2|3|4|5|6|7|T|8|@$9|U|A|V|B|C]|$9|W|A|X|B|C]|$9|Y|A|Z|B|C]|$9|10|A|11|B|C]|$9|12|A|13|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|14|8|@$9|15|A|16|B|C]|$9|17|A|18|B|C]|$9|19|A|1A|B|C]|$9|1B|A|1C|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|1D|8|@$9|1E|A|1F|B|C]]|D|@$9|1G|A|1H|1|1I]|$9|1J|A|1K|1|1L]]|E|$]]|$1|J|3|-4|5|6|7|1M|8|@]|D|@]|E|$]]]|K|$L|$5|M|N|O|E|$P|Q]]|R|$5|M|N|O|E|$P|S]]]]

Outlook Object Model always tries to represent signed and encrypted messages as regular <code>MailItem</code> objects. The <code>MessageClass</code> property will return "<code>IPM.Note"</code>. It goes as far as returning a fake <code>IMessage</code> object from the <code>MailItem.MAPIOBJECT</code> property.

If you are using Extended MAPI, you can read the <code>PR_MESSAGE_CLASS</code> property and check if its value corresponds to one of the signed/encrypted message classes (e.g. <code>"IPM.Note.SMIME.MultipartSigned"</code>). Just make sure to unwrap the <code>IMessage</code> object if you are retrieving it from the <code>MailItem.MAPIOBJECT</code> property.

You can also use <a href="http://www.dimastr.com/redemption/" rel="nofollow noreferrer">Redemption</a> and and its <a href="http://www.dimastr.com/redemption/rdoencryptedmessage.htm" rel="nofollow noreferrer">RDOEncryptedMessage</a> object - it allows to decrypt an encrypted message using <code>RDOEncryptedMessage.GetDecryptedMessage</code> message as well as access the certificate properties.

blocks|key|2606190|text|如果您有一个真正签名的S/MIME邮件，那么"smime.p7m“附件将有一个Content-Type值application/pkcs7-mime;+smime-type=signed-data+-或者-它将有一个Content-Type值application/pkcs7-signature，并且将是multipart/signed容器的第二个子MIME部分。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2606191|要可视化，请执行以下操作：|2606192|选项1：|2606193|Content-Type:+application/pkcs7-mime;+smime-type="signed-data";+name="smime.p7m"
Content-Disposition:+attachment;+filename="smime.p7m"
Content-Transfer-Encoding:+base64|code-block|syntax|javascript|2606194|选项2：|2606195|Content-Type:+multipart/signed;+boundary="some-bounary-string";+protocol="application/pkcs7-signature"

--some-boundary-string
Content-Type:+text/plain

This+is+the+message+content+that+was+signed...

--some-boundary-string
Content-Type:+application/pkcs7-signature;+name="smime.p7m"
Content-Disposition:+attachment;+filename="smime.p7m"
Content-Transfer-Encoding:+base64

...
--some-boundary-string--|2606196|我不熟悉Exchange+MAPI+wrapper+API，但应该有一种方法来获取Content-Type值。根据这是什么，您可以检查我上面提到的其他属性，以验证它实际上是一封签名邮件还是仅仅是一个附件。|2606197|注意:它们也可以是application/x-pkcs7-mime和application/x-pkcs7-signature，但除了MIME子类型的前导x-之外，逻辑是相同的。|2606198|entityMap^0|13|C|1G|1A|30|C|3D|R|49|G|0|0|0|0|0|0|15|C|0|9|O|Y|T|25|2|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]|$9|11|A|12|B|C]|$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|19|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|1A|8|@]|D|@]|E|$]]|$1|J|3|K|5|L|7|1B|8|@]|D|@]|E|$M|N]]|$1|O|3|P|5|6|7|1C|8|@]|D|@]|E|$]]|$1|Q|3|R|5|L|7|1D|8|@]|D|@]|E|$M|N]]|$1|S|3|T|5|6|7|1E|8|@$9|1F|A|1G|B|C]]|D|@]|E|$]]|$1|U|3|V|5|6|7|1H|8|@$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]|$9|1M|A|1N|B|C]]|D|@]|E|$]]|$1|W|3|-4|5|6|7|1O|8|@]|D|@]|E|$]]]|X|$]]

If you have a truly signed S/MIME message, then the "smime.p7m" attachment will either have a <code>Content-Type</code> value of <code>application/pkcs7-mime; smime-type=signed-data</code> -or- it will have a <code>Content-Type</code> value of <code>application/pkcs7-signature</code> and will be the 2nd child MIME part of a <code>multipart/signed</code> container.

To visualize:

Option 1:

<pre><code>Content-Type: application/pkcs7-mime; smime-type="signed-data"; name="smime.p7m"
Content-Disposition: attachment; filename="smime.p7m"
Content-Transfer-Encoding: base64
</code></pre>

Option 2:

<pre><code>Content-Type: multipart/signed; boundary="some-bounary-string"; protocol="application/pkcs7-signature"

--some-boundary-string
Content-Type: text/plain

This is the message content that was signed...

--some-boundary-string
Content-Type: application/pkcs7-signature; name="smime.p7m"
Content-Disposition: attachment; filename="smime.p7m"
Content-Transfer-Encoding: base64

...
--some-boundary-string--
</code></pre>

I'm not familiar with the Exchange MAPI wrapper API, but there should be a way to get the <code>Content-Type</code> value. Depending on what that is, you can check for the other attributes I mentioned above to verify if it is actually a signed message or just an attachment.

Note: They can also be <code>application/x-pkcs7-mime</code> and <code>application/x-pkcs7-signature</code>, but other than the leading <code>x-</code> of the MIME subtype, the logic is the same.

I would like to know if it's possible, using VB.Net, to check if an e-mail is digitally signed and who is the issuer of the certificate.

Using Extended MAPI Wrapper and Cryptography I was able to get the smime.p7m attachment from an e-mail and get the certificate information out of it (including the issuer), so it seemed like everything was working. The issue is that if I send an unsigned e-mail and manually attach a smime.p7m file, it will trick the code into thinking that the e-mail is signed.

Does anyone have a solution for this? I can also use other methods like Outlook Interop.

Check if email is digitally signed using VB.Net

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我想知道是否可以使用VB.Net检查电子邮件是否经过数字签名，以及谁是证书的颁发者。使用扩展的MAPI包装器和加密技术，我能够从电子邮件中获得smime.p7m附件，并从中获得证书信息(包括颁发者)，所以看起来一切都正常。问题是，如果我发送了一封未签名的电子邮件，并手动附加了一个smime.p7m文件，它将欺骗代码，使...

问检查电子邮件是否使用VB.Net进行了数字签名
EN

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