Creating PKCS12 Certificates

PKCS12, Personal Information Exchange Syntax Standard, certificates can be used for things such as email signing and file signing. They are different from other certificates in that rather than being only the public or private certificate, they are a combination of both plus the root certificate. This means the person they are made for only has to worry with one file.

Note: The author of this page, and owner of this web site, is not to be held liable for any damage or trouble arising from following these directions. You are responsible for your own security, use, and creation of certificates.

See and for more information.

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Quick steps:

  1. Setup and create root certificate.
  2. For each person create a key and signing request.
  3. Sign each request.
  4. Create the PKCS12 file.
  5. Distribute the file(s).

The following covers the command-line way of doing it on Linux using OpenSSL. If you are using a GUI, it should be fairly simple to follow along.

1) Setup and create root certificate

See Setting up OpenSSL to Create Certificates

Note: If all you are going to be creating is certificates to sign files and/or emails, and have an old box around I highly recommend loading it up with Apache, PHP, OpenSSL. Install PHPki and use it to create and manage your certificates. However, make sure this computer is not accessible over the internet.

2) For each person create a key and signing request

Assuming you have your root certificate created and you are in the 'sslcert' directory you can start creating certificates for each person in your company, or at least each one you want to be able to digitally sign drawings (or email or anything else certificates can be used for).

Type (all one line):
openssl req -new -nodes -out name-req.pem -keyout private/name-key.pem -days 365 -config ./openssl.cnf

Note the number of days. For employee certificates I like to keep this fairly short, but a year may be too short. For a newly hired person you might want to do it for the length of their probation period and then reissue it for longer after that.

You will be prompted for information, much like when creating the root certificate. I put "Employee" for the Organizational Unit, make sure to use their correct internet email address for Email Address, and use their full name for Common Name.

Name Field Explanation Example
Country Name The two-letter ISO abbreviation for your country US = United States
State or Province Name The state or province where your organization is located. Can not be abbreviated. Georgia
City or Locality The city where your organization is located. Atlanta
Organization Name The exact legal name of your organization. Do not abbreviate SSL Secure Inc.
Organizational Unit Optional for additional organization information. Marketing
Common Name The person's full name. Jane R Doe
Email address The person's email address someone@your.domain

Once you are done with the input, two files will be created:
name-req.pem - the request
name-key.pem - the private key in the private directory

3) Sign each request

This will generate the certificate.

openssl ca -out name-cert.pem -days 365 -config ./openssl.cnf -infiles name-req.pem

You will be prompted for the password used when creating the root certificate. Then you will be given a chance to review the information before signing. If anything is incorrect, now is the time to stop and redo things.

Two files are created:
name-cert.pem - which is the certificate
<number>.pem - a copy of it in the certs directory.

4) Create the PKCS12 file

This file combines the person's public key, private key, and root certificate into one file.

Type (all one line):
openssl pkcs12 -export -in name-cert.pem -inkey private/name-key.pem -certfile cacert.pem -name "[friendly name]" -out name-cert.p12

[friendly name] can be what you want, but I use the person's full name (note: do not enclose any part of this with quotes, such as a nick name). You will be prompted for an "export password". This is what the user will use when they import the file and if they lose this file and need to export it from a storage "service" for use elsewhere. I let my people come over and type their own, since it is unchangeable once created.

Before you transfer them, note that the p12 format is binary and the pems are text. (This matters with FTP and a few other situations.) Also remember that the name-key.pem is the private key and should be guarded, whereas the name-cert.pem is the public certificate. While name-cert.p12 is encrypted with the password, it does contain the private key so I wouldn't leave it laying out for just anyone to get to.

5) Distribute the file(s)

The name-cert.p12 file is the one to give the person. They will need to know the export password used when creating the file. You can also give them their name-cert.pem and name-key.pem if you want. However, stress that if the name-cert.p12 file or the name-key.pem is compromised, ie lost or misplaced, that they must tell you immediately. Then you must revoke their existing one and issue a new one.

How the users import them depends on the application.

How to verify signatures

Thanks all for the tutorial and the comments, now we have the working digital signatures, but how do a recipient verify a digital signature on his side? What do they need to do?

Thank you very much for your

Thank you very much for your great tutorial


Thank you for the great tutorial professional resume concernong creating PKCS12 Certificates.

how create pkcs12 in openssl in windows

I download openssl - win32 from net and install it . all thing is ok but i cannot create pkcs12 .why?
please help me .

Flat Mountain: Creating PKCS12 Certificates webpage

I had zero trouble. Thank You. I must have searched for a solution
to create a pkcs#12 file for six hours. You offered help; shortest route from
point a to point b. Thanks.


private key error


I have tried the export method several times, but it gives me the same error: "unable to load private key". I made sure that they key is a .pem file but it sill does not work.

Valid digital signature but no email address in certificate

I followed your directions - did it twice to verify, I got the same results.

I can import the certificate into Thunderbird, but when I send a test message and digitally sign it, The receiver of the email in Thunderbird gets this message:
"Although the digital signature is valid, it is unknown whether sender and signer are the same person. The certificate used to sign the message does not contain an email address."

I created the certificate twice and I'm sure I added a email address when I was prompted.

Any ideas what I doing incorrectly.

P.S. Wonderful job on putting all this SSL information together!

Got it!

I changed email_in_dn = no to email_in_dn = yes in the [cn] section of the openssl.cnf file and email addresses are now in the generated certificates.

Again thanks for all your work on this!! Great job!!

When I try the steps, I get

When I try the steps, I get the following error on the last PKCS12 generation phase: "No certificate matches private key"

Any ideas on what could be wrong?


You have to use the private

You have to use the private key generated with the request of your new certificate not the one that belongs to the CA.


As a mineral and vegetable and alien i accept that me and my company and organisation accept and respect the terms