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Questions tagged [smime]

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

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Manually verifying signature in S/MIME mail with openssl

I'm trying to manually verify the signature in an S/MIME signed email with openssl as part of a homework. While I have the mail and can extract the chain of certificates, I'm failing to extract the ...
aram's user avatar
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2 votes
2 answers
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SMIME email decryption using a private key - what am I doing wrong?

I have an encrypted .eml file and a private key. I've looked it up a lot on the internet but couldn't find a way to decrypt the email using OpenSSL. I've tried this command: smime -decrypt -in ...
Daniel's user avatar
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1 answer
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Force specific encryption cipher for S/MIME mails

I have a number of contacts who can only decrypt 3DES, when it comes to S/MIME encrypted mails. I'm aware that this is by far not ideal, but better than no encryption at all. My problem is, that I ...
GarlicCheese's user avatar
2 votes
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351 views

Certificate Transparency and S/MIME certificates

When people speak about CT that usually means only TLS certificates are stored in log. However, CT probable might be considered for usage in other PKI-based technologies. Is CT designed to log S/MIME ...
tysonite's user avatar
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1 answer
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Incomplete decryption of S/MIME mails using openssl cms

We're receiving signed and encrypted mails from many senders. For most senders, the decryption with openssl works fine using the following command: openssl cms -decrypt -recip <path-to-key> -in &...
lmr2391's user avatar
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iOS (iPhone) S/MIME certificate with multiple addresses

On an iPhone I have a mail account in the native Mail app with two distinct e-mail addresses, and a certificate that lists both of those e-mail addresses in the SAN field. When I try to send mail with ...
Chris Owens's user avatar
1 vote
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Get S/MIME from Digicert, store in escrow on on-prem CA

I'm trying to crack the following nut: I have a contract with Digicert for S/MIME certificates for my org. Digicert allows to use their API for cert issuance. Unfortunately I can't let users self-...
StanTastic's user avatar
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Digital Signature is not valid

I recently received a digital signed email from a friend and the certificate is issued by COMODO RSA Client Authentication and Secure Email. My problem is the thunderbird detect it as a "Not Valid ...
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Replying to a digitally signed email using thunderbird

So Basically I sent a digitally signed email using a certificate issued by Sectigo RSA Client Authentication and Secure Email CA. Now the recipient of the email replied to me with a certificate ...
madaoislife's user avatar
1 vote
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712 views

How should an ISP approach Mutual Auth TLS for SMTP email? (Domain Auth Email)

I'm looking for an easy to deploy way to make email clients (MUAs) display my email messages in a secure manner. PGP and SMIME both do this today, but they are high touch, and require software or ...
makerofthings7's user avatar
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Distribute S/MIME public keys and CA cert for email security

I have my own CA. I want to distribute S/MIME certificates for 10 different users. I saw S/MIME keyservers from http://wiki.cacert.org/KeyServers, but I don't want to use public servers. What is the ...
sfallahdoost's user avatar
1 vote
1 answer
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Automatically import/deploy/distribute private key to users for use with S/MIME

it is an Environment with Microsoft Active Directory, Exchange and Windows/Outlook as Client. Now there are the users which have their own private certificates to send signed mails and encrypt ...
Blafasel's user avatar
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How to add MIME headers in encrypt and sign SMIME data using openssl smime command

I was trying to encrypt and sign MIME data using openssl smime command. I have below MIME data - From:"=?ISO-8859-1?B?3M0SEg=?=" <[email protected]> Subject:=?ISO-8859-1?B?yNA==?= =?ISO-...
scodeninja's user avatar
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Guidance: S/MIME Signed Certificate invalid for many clients even though it worked previously and still works

I have a very strange problem and i would like to get some guidance on this. Problem description: My application is sending S/MIME signed Email messages to clients. It worked perfectly no problems ...
Lorem ipsum's user avatar
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openssl smime sign and encrypt loads

I am trying to investigate openssl S/MIME in order to both sign and encrypt loads to be transfered over an untrusted network. Loads need to be protected in authenticity and confidentiality. I have ...
philippe's user avatar
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Does SMIME 4, or any prior version, support multiple private keys for a single individual?

I am investigating S/MIME and if it's possible to have a device-specific signing key (or if that's a good idea). The intention is to reduce risk by making the private key read only on the device(es) ...
Ran Dom's user avatar
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Using a PowerShell Self-Signed Certificate for Outlook S/MIME

I'm testing out a way that myself and a few others could use S/MIME for our email traffic. I'm using Outlook 2016 with Win10. I have generated my test certificate with the following command in ...
Ian's user avatar
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hashing algorithm mail signing

What determines the hashing algorithm used form mail signing? I sign an mail. it is first run through a hashing algorithm and next encrypted with my private key. Bob, the receiver will decrypt it with ...
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What public key systems allow for delegation?

I am looking for a public key system that allows for a 3rd party to use that key for other purposes. What private key systems allow for this? PGP, S/MIME, PKI?
makerofthings7's user avatar