S/MIME is a protocol for encrypting and signing messages, e.g. emails.

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18
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3answers
978 views

Can a nation-state adversary perform a MITM attack by compelling a CA to issue them with fake certs?

As I understand it, with any encryption system based on a trust chain / CAs (eg SSL, TLS, S/MIME), it would be possible for a nation-state adversary (such as the NSA) to compel the CA to issue them ...
8
votes
2answers
6k views

OpenSSL PKCS#7 vs. S/MIME

OpenSSL 1.0.1c onwards seems to offer CMS support. I have difficulty understanding the difference between smime and pkcs7. S/MIME specs are layered on PKCS#7 (so says Wikipedia). Now in openssl I ...
9
votes
2answers
426 views

I want trusted SMIME certificates for 3rd parties. Is this a reasonable configuration?

I want to send out SMIME certificates with my emails, and want to deploy the following PKI Root01 (All EKU, All Constrants, No Restrictions) PolicyInt01 (Internal applications, not trusted by 3rd ...
5
votes
1answer
5k views

Which extensions to use for a S/MIME certificate?

Analogously to the SSL server certificate question, which extensions should I use for S/MIME, and should the CA be restricted somehow as well? (I'm using openssl, which at the moment creates CA and ...
2
votes
3answers
2k views

What is the web of trust?

I'm studying network and system security and I came across the phrase "web of trust". From Wikipedia: In cryptography, a web of trust is a concept used in PGP, GnuPG, and other OpenPGP-...
3
votes
2answers
512 views

Can I buy a signing-valid certificate for internal use?

So now that I have to implement "secure transport" as defined by The Direct Project (not to mention reinventing a bunch of wheels, but that's another story for SO), I find myself staring down the ...
5
votes
1answer
497 views

Apart from the lack of native Oultook support, why should one prefer S/MIME over PGP/MIME for email?

From my (still quite subjective) point of view, GnuPG/PGP is superior to SSL (or more specifically, PGP/MIME over S/MIME; maybe in other areas SSL is the better choice), e.g. due to the support of ...
9
votes
2answers
3k views

Obtaining an S/MIME certificate without disclosing my private key to the TTP

I would like to obtain a trusted S/MIME certificate, but all the certificate authorities I have asked so far generate the keypair on their server, sign the certificate and send me both the private key ...
3
votes
1answer
132 views

Does PKCS #7 (CMS) add assurance to an email if a CRL/OCSP response is included, then revoked?

Suppose I issue a signing certificate in January, and have a daily CRL issued (expires in 1 day) to verify the validity of that signature. Then sometime in July I need to revoke that certificate. My ...
3
votes
1answer
383 views

Are WoSign S/MIME certificates generated on the server side and therefore unsafe to use?

WoSign has been in the media for offering free server and client certificates. Since one of my (free) S/MIME certificate from another CA is about to expire soon after one year and WoSign offers ...