S/MIME signature verification not shown on eml files

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albertlevi
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Joined: May 20th, 2021, 5:52 am

S/MIME signature verification not shown on eml files

Post by albertlevi »

Hi,

I have a valid signed email message. When I check it within folder, signature seal is shown. However, when I export as eml file and double click on it, message is shown but signature seal is not shown. The signature attachment still exists in the eml file.

Anybody knows a remedy for this.
Regards
Albert Levi
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LIMPET235
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Re: S/MIME signature verification not shown on eml files

Post by LIMPET235 »

Moving this to Thunderbird Support...
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tanstaafl
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Re: S/MIME signature verification not shown on eml files

Post by tanstaafl »

Did you import the necessary certificate authority (CA) for whatever certificate was used?

If you use view -> message source (or Ctrl-U) to look at the raw message source, what are the headers for the MIME section that adds the digital signature?
albertlevi
Posts: 3
Joined: May 20th, 2021, 5:52 am

Re: S/MIME signature verification not shown on eml files

Post by albertlevi »

Yes CAs are there. Actually seal is shown when I open the message in the folder. The problem is when I open as an independent eml file.

Signatures are also in place in the eml file(below):

Content-Type: application/pkcs7-signature; name="smime.p7s"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="smime.p7s"
Content-Description: S/MIME Cryptographic Signature
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tanstaafl
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Re: S/MIME signature verification not shown on eml files

Post by tanstaafl »

I'm out of town right now. Let me try to duplicate your problem Sunday.

What companies S/MIME certificate are you using? Last I looked most of the free ones are no longer available and Actalis doesn't let you use a browser to generate the private key, but will generate it themselves and send you it.

https://thomas.vanhoutte.be/miniblog/wh ... 3-options/
albertlevi
Posts: 3
Joined: May 20th, 2021, 5:52 am

Re: S/MIME signature verification not shown on eml files

Post by albertlevi »

For some senders it was Comodo (the senders were Comodo employees). Last one I tried was by getting a certificate from Actalis. They are all the same. I do not think that it is related to CA since the signature is shown to be verified if the email was opened in inbox.

Thanks
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