Generate Key File From Crt Ubuntu

  1. Generate Key File From Crt Ubuntu Free
  2. Generate Key File From Crt Ubuntu Download

How do I make my own bundle file from CRT files? Answer: You may do this using you favorite text editor or by using the command line. Example: # Root CA Certificate - AddTrustExternalCARoot.crt # Intermediate CA Certificate 1 - ComodoRSAAddTrustCA.crt OR ComodoECCAddTrustCA.crt.

There are numerous articles I’ve written where a certificate is a prerequisite for deploying a piece of infrastructure.

This article will guide you through creating a trusted CA (Certificate Authority), and then using that to sign a server certificate that supports SAN (Subject Alternative Name).

Operationally, having your own trusted CA is advantageous over a self-signed certificate because once you install the CA certificate on a set of corporate/development machines, all the server certificates you issue from that CA will be trusted. If you manage a larger sized internal environment where hosts, services, and containers are in constant flux, this is an operational win.

  1. The insecure key is now named server.key, and you can use this file to generate the CSR without passphrase. To create the CSR, run the following command at a terminal prompt: openssl req -new -key server.key -out server.csr.
  2. Privkey.pem is the 'key' file. Sometimes it is improperly named as cert.key or example.com.key. Fullchain.pem is your 'crt' file. Sometimes it is improperly named as example.com.crt. CRT/KEY Bundle. Bundle.pem would be made like so: cat fullchain.pem privkey.pem bundle.pem. HAProxy is the only server that I know of that uses bundle.pem.
  3. # Note, the -certfile root.crt appends all CA certs to the export, I've never needed these so it's optional for my personal steps $ openssl pkcs12 -export -in hostname.crt -inkey hsotname.key -certfile root.crt -out hostname.p12 # Note, I've always had my hostname.crt as part of my.pem, so I keep my certs but apparently you may not have to.
  4. Aug 26, 2019.key.pem +.crt.pem in one file =.keycer.pem; Generate Self-Signed Certificate with subjectAltName. We will be using.crt file instead, so create one using the following command. To copy the files from inside Ubuntu, you need to know where you want to copy the files to on Windows side.

CA trust also had advantages to self-signed certs because browsers like Chrome 58 and Firefox 48 have limitations on trusting self-signed certificates. The Windows version of Chrome is the only flavor that allows self-signed certs to be imported as a trusted root authority, all other OS do not trust the self-signed certificate. And Firefox allows you to add a permanent exception, but needs a trusted CA in order to show a fully green trust lock icon.

If you just want a self-signed SAN certificate with no backing CA, then read my article here instead, but note that it has limitations that are overcome by using a trusted CA.

Overview

Generate key file from crt ubuntu download

If you are familiar with commercial certificates, you know that a certificate does not live in isolation. It it just the beginning of a chain of trust, where the root certificate is ultimately trusted because it sits on your local system.

We can create a SAN certificate with the same features, issued and signed by a Certificate Authority that we create. This has several benefits:

  1. Better emulation of production – production certs also consist of a chain
  2. Ease of administration – once a user trusts our CA, then any other SAN certificate we generate will also be trusted
  3. Better browser support – not all browsers allow self-signed certs to be added into the trusted root authorities list

In this article, first we will create our own CA (Certificate Authority). Then we will use that CA to create a SAN server certificate that covers “mydomain.com” as well as any of its subdomains, “*.mydomain.com”.

If you want to test the certs we generate here, I would recommend using HAProxy. Here is a page where I describe how to do a quick HAProxy install.

Prerequisite

As a prerequisite, ensure the SSL packages are installed:

Customized openssl.cnf

The first step is to grab the openssl.cnf template available on your system. On Ubuntu this can be found at “/usr/lib/ssl/openssl.cnf”. You may find this in “/System/Library/OpenSSL/” on MacOS, and “/etc/pki/tls” on Redhat variants.

“$prefix.cnf” needs be modified with the specific information about the cert we are going to generate.

Under the [ v3_ca ] section, add the following values. For the CA, this signifies we are creating a CA that will be used for key signing.

Then under the “[ v3_req ]” section, set the following along with all the valid alternative names for this certificate.

Also uncomment the following line under the “[ req ]” section so that certificate requests are created with v3 extensions.

When we generate each type of key, we specify which extension section we want to use, which is why we can share $prefix.cnf for creating both the CA as well as the SAN certificate.

Create CA certificate

Now we will start using OpenSSL to create the necessary keys and certificates. First generate the private/public RSA key pair:

This encodes the key file using an passphrase based on AES256. Then we need to create the self-signed root CA certificate.

You can verify this root CA certificate using:

This will show the root CA certificate, and the ‘Issuer’ and ‘Subject’ will be the same since this is self-signed. This is flagged as “CA:TRUE” meaning it will be recognized as a root CA certificate; meaning browsers and OS will allow it to be imported into their trusted root certificate store.

Create Server certificate signed by CA

With the root CA now created, we switch over to the server certificate. First generate the private/public RSA key pair:

We didn’t put a passphrase on this key simply because the CA is more valuable target and we can always regenerate the server cert, but feel free to take this extra precaution.

Generate Key File From Crt Ubuntu Free

Then create the server cert signing request:

Then generate the server certificate using the: server signing request, the CA signing key, and CA cert.

The “$prefix.key.pem” is the server private key and “$prefix.crt” is the server certificate. Verify the certificate:

This will show the certificate, and the ‘Issuer’ will be the CA name, while the Subject is the prefix. This is not set to be a CA, and the ‘Subject Alternative Name’ field contains the URLs that will be considered valid by browsers.

Server deployment

Servers like HAProxy want the full chain of certs along with private key (server certificate+CA cert+server private key). While Windows IIS wants a .pfx file. Here is how you would generate those files.

Browser Evaluation

When you first point Chrome or Firefox at the site with your SAN cert with CA signing, it will throw the same type of exceptions as a self-signed SAN cert. This is because the root CA cert is not known as a trusted source for signed certificates.

Generate public key from ppk mac. Now convert the PPK keys to SSH keypairs:cache search. To generate the private key: cd puttygen iddsa.ppk -O private-openssh -o iddsa. And to generate the public key: puttygen iddsa.ppk -O public-openssh -o iddsa.pub. Move these keys to /.ssh and make.

In Chrome settings (chrome://settings), search for “certificates” and click on “Manage Certificates”. On Windows this will open the Windows certificate manager and you should import the “ca.pem” file at the “Trusted Root Certification Authorities” tab. This is equivalent to adding it through mmc.exe, in the “local user” trusted root store (not the computer level). On Linux, Chrome manages its own certificate store and again you should import “ca.pem” into the “Authorities” tab. This should now make the security icon turn green.

In Firefox Options (about:preferences), search for “certificates” and click “View Certificates”. Go to the “Authorities” tab and import “ca.pem”. Check the box to have it trust websites, and now the lock icon should turn green when you visit the page.

Although there is a little friction doing this import, it is a one-time cost because any other certificates that you sign with this CA are now trusted. So if a cert expires and you have to replace it, or you need to change the URLs in a SAN and refresh it, none of the browsers will have an issue with trust.

REFERENCES

https://gist.github.com/jhamrick/ac0404839b5c7dab24b5 (script for CA and SAN)

https://github.com/stanzgy/wiki/blob/master/network/openssl-self-signed-certs-cheatsheet.md (exact commands for CA, intermediate, chain, server cert, validating cert+key)

https://gist.github.com/bitoiu/9e19962b991a71165268 (original source of quick SAN with no intermediate)

Generate Key File From Crt Ubuntu Download

https://jamielinux.com/docs/openssl-certificate-authority/create-the-root-pair.html (multiple pages of detailed lead through for CA, intermediate, and cert)

https://security.stackexchange.com/questions/38782/ssl-tls-distinction-between-self-signed-cert-and-self-signed-ca-and-other-que (discussion on CA vs Self signed)

https://stackoverflow.com/questions/5244129/use-rsa-private-key-to-generate-public-key (discussion on RSA public/private pair and info inside)

https://stackoverflow.com/questions/5935369/ssl-how-do-common-names-cn-and-subject-alternative-names-san-work-together (explains how RFC 6125 from 2011 says SAN checked first)

https://github.com/webpack/webpack-dev-server/issues/854 (self signed cert no longer valid chrome 58)

https://bugs.chromium.org/p/chromium/issues/detail?id=700595&desc=2 (chrome 58 needs SAN for self-certs)

https://gist.github.com/akailash/7ec96e39d6951dd2293308e1d8055307 (wildcard SAN with CA, also shows how to add as trusted cert at linux level)

https://www.chromium.org/administrators/policy-list-3#EnableCommonNameFallbackForLocalAnchors (temporary workaround for chrome 58)

http://users.skynet.be/pascalbotte/art/server-cert.htm (use Jetty jar to transform pkcs12 to jks java keystore)

NOTES

On Ubuntu, trusted root certificates sit in the directory “/etc/ssl/certs”, and can be updated using “sudo update-ca-certificates”. On Windows it is managed through the MMC Certificate Snap-In.

If you don’t want to manually type the password, you can use passin/passout:

Now use that CA to create the root CA certificate.

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The Application Gateway v2 SKU introduces the use of Trusted Root Certificates to allow backend servers. This removes authentication certificates that were required in the v1 SKU. The root certificate is a Base-64 encoded X.509(.CER) format root certificate from the backend certificate server. It identifies the root certificate authority (CA) that issued the server certificate and the server certificate is then used for the TLS/SSL communication.

Application Gateway trusts your website's certificate by default if it's signed by a well-known CA (for example, GoDaddy or DigiCert). You don't need to explicitly upload the root certificate in that case. For more information, see Overview of TLS termination and end to end TLS with Application Gateway. However, if you have a dev/test environment and don't want to purchase a verified CA signed certificate, you can create your own custom CA and create a self-signed certificate with it.

Note

Self-signed certificates are not trusted by default and they can be difficult to maintain. Also, they may use outdated hash and cipher suites that may not be strong. For better security, purchase a certificate signed by a well-known certificate authority.

In this article, you will learn how to:

  • Create your own custom Certificate Authority
  • Create a self-signed certificate signed by your custom CA
  • Upload a self-signed root certificate to an Application Gateway to authenticate the backend server

Prerequisites

  • OpenSSL on a computer running Windows or Linux

    While there could be other tools available for certificate management, this tutorial uses OpenSSL. You can find OpenSSL bundled with many Linux distributions, such as Ubuntu.

  • A web server

    For example, Apache, IIS, or NGINX to test the certificates.

  • An Application Gateway v2 SKU

    If you don't have an existing application gateway, see Quickstart: Direct web traffic with Azure Application Gateway - Azure portal.

Create a root CA certificate

Create your root CA certificate using OpenSSL.

Create the root key

  1. Sign in to your computer where OpenSSL is installed and run the following command. This creates a password protected key.

  2. At the prompt, type a strong password. For example, at least nine characters, using upper case, lower case, numbers, and symbols.

Create a Root Certificate and self-sign it

  1. Use the following commands to generate the csr and the certificate.

    The previous commands create the root certificate. You'll use this to sign your server certificate.

  2. When prompted, type the password for the root key, and the organizational information for the custom CA such as Country, State, Org, OU, and the fully qualified domain name (this is the domain of the issuer).

Create a server certificate

Next, you'll create a server certificate using OpenSSL.

Create the certificate's key

Use the following command to generate the key for the server certificate.

Create the CSR (Certificate Signing Request)

The CSR is a public key that is given to a CA when requesting a certificate. The CA issues the certificate for this specific request.

Note

The CN (Common Name) for the server certificate must be different from the issuer's domain. For example, in this case, the CN for the issuer is www.contoso.com and the server certificate's CN is www.fabrikam.com.

  1. Use the following command to generate the CSR:

  2. When prompted, type the password for the root key, and the organizational information for the custom CA: Country, State, Org, OU, and the fully qualified domain name. This is the domain of the website and it should be different from the issuer.

Generate the certificate with the CSR and the key and sign it with the CA's root key

  1. Use the following command to create the certificate:

Verify the newly created certificate

  1. Use the following command to print the output of the CRT file and verify its content:

  2. Verify the files in your directory, and ensure you have the following files:

    • contoso.crt
    • contoso.key
    • fabrikam.crt
    • fabrikam.key

Configure the certificate in your web server's TLS settings

In your web server, configure TLS using the fabrikam.crt and fabrikam.key files. If your web server can't take two files, you can combine them to a single .pem or .pfx file using OpenSSL commands.

IIS

For instructions on how to import certificate and upload them as server certificate on IIS, see HOW TO: Install Imported Certificates on a Web Server in Windows Server 2003.

For TLS binding instructions, see How to Set Up SSL on IIS 7.

Apache

The following configuration is an example virtual host configured for SSL in Apache:

NGINX

The following configuration is an example NGINX server block with TLS configuration:

Access the server to verify the configuration

  1. Add the root certificate to your machine's trusted root store. When you access the website, ensure the entire certificate chain is seen in the browser.

    Note

    It's assumed that DNS has been configured to point the web server name (in this example, www.fabrikam.com) to your web server's IP address. If not, you can edit the hosts file to resolve the name.

  2. Browse to your website, and click the lock icon on your browser's address box to verify the site and certificate information.

Verify the configuration with OpenSSL

Or, you can use OpenSSL to verify the certificate.

Upload the root certificate to Application Gateway's HTTP Settings

To upload the certificate in Application Gateway, you must export the .crt certificate into a .cer format Base-64 encoded. Since .crt already contains the public key in the base-64 encoded format, just rename the file extension from .crt to .cer.

Azure portal

To upload the trusted root certificate from the portal, select the HTTP Settings and choose the HTTPS protocol.

Azure PowerShell

Or, you can use Azure CLI or Azure PowerShell to upload the root certificate. The following code is an Azure PowerShell sample.

Note

The following sample adds a trusted root certificate to the application gateway, creates a new HTTP setting and adds a new rule, assuming the backend pool and the listener exist already.

Verify the application gateway backend health

  1. Click the Backend Health view of your application gateway to check if the probe is healthy.
  2. You should see that the Status is Healthy for the HTTPS probe.

Next steps

To learn more about SSLTLS in Application Gateway, see Overview of TLS termination and end to end TLS with Application Gateway.