Making a self-signed TLS certificate: Difference between revisions

Revision as of 00:57, 11 April 2016

Sending data over the internet unencrypted means anybody with the right tools can see this data. Making a certificate means that you can then encrypt the data. This means that the data is no longer readable to anybody that doesn't have your certificate. This guide will show you how to make a certificate authority, sign and make an SSL certificate ready to be used by your web server.

Due to the way the encryption landscape has changed on the internet, we will be creating a ECDSA certificate. EC stands for Elliptic Curve and uses prime number curves which allow smaller key sizes for the same amount or better protection than the larger traditional key sizes.

What you need to know

You will be making a self-signed certificate. This will make all browsers through up an error. This is OK and can usually be avoided in the future by using an exception.
To make it easier, it is suggested to make all the certificates in a dedicated folder somewhere that you have easy access to, for example in your home folder. This will avoid permission problems.
If your making a certificate without a password, the resulting certificate must be kept in a safe place. If this certificate is EVER disclosed, any data can be decrypted from the server and you must revoke the certificate. The newest versions of Apache only allow www and root users to read the key folder by default.
Many of the fields when making a certificate authority or server certificate are dated. The ones marked (OPTIONAL) don't have to be filled in.

Create an elliptic curve private key

Open a terminal window.
Type the following into the terminal:

 # openssl ecparam -genkey -name prime256v1 -out key.pem

NOTE: This is the private key that must be kept safe. If anyone gets hold of this, they will be able to decrypt your data.

Creating a Certificate Signing Request (CSR)

A certificate signing request combines the private key and some information to fill out the certificate with and makes a public key out of this information.

Type the following into the terminal:

 openssl req -new -key key.pem -out csr.pem

You will be presented with some options to fill out:

Type in a Country code when asked (GB for England).
Type in a State or Provence (or County in England) when asked. (OPTIONAL)
Type in a Locality (a town or city) when asked. (OPTIONAL)
Type in an Organisation name (or company name) when asked. If left blank, it will be filled with 'Internet Widgets Pty'. (OPTIONAL)
Type in an Organisation unit (or department within company) when asked. (OPTIONAL)
Type in a Common name when asked. This is is usually a FQDN, but can be what you usually how you access the page by (IP address, hostname, or FQDN)
Type in an e-mail address when asked. This is the e-mail address people will contact you on if there is a problem with the certificates. Make sure you type an address you would access often enough.
Type a challenge password (this will stop the private key being accessible, but is not required. If going for simplicity, don't type a password) (OPTIONAL)
Type an optional company name (this is an extra attribute and isn't required) (OPTIONAL)

Creating the certificate

With the private key and the certificate signing request we made earlier, we can now make the certificate.

Type the following into the terminal:

openssl req -x509 -days 365 -rand /dev/urandom -key key.pem -in csr.pem -out cert.pem

Securing Apache with created certificate

See the following article:

Securing Apache with an SSL/TLS certificate

External Links

https://msol.io/blog/tech/create-a-self-signed-ecc-certificate/

Thanks for the information, your site helped us change over to ECDSA!

@@ Line 1: / Line 1: @@
-Sending data over the internet unencrypted means anybody with the right tools can see this data. Making a certificate means that you can then encrypt the data. This means that the data is no longer readable to anybody that doesn't have the certificate. This guide will show you how to make a certificate authority, sign and make an SSL certificate ready to be used by your web server.
+Sending data over the internet unencrypted means anybody with the right tools can see this data. Making a certificate means that you can then encrypt the data. This means that the data is no longer readable to anybody that doesn't have your certificate. This guide will show you how to make a certificate authority, sign and make an SSL certificate ready to be used by your web server.
-==What you need to know==
+Due to the way the encryption landscape has changed on the internet, we will be creating a ECDSA certificate. EC stands for Elliptic Curve and uses prime number curves which allow smaller key sizes for the same amount or better protection than the larger traditional key sizes.
+== What you need to know ==
 * You will be making a self-signed certificate. This will make all browsers through up an error. This is OK and can usually be avoided in the future by using an exception.
 * To make it easier, it is suggested to make all the certificates in a dedicated folder somewhere that you have easy access to, for example in your home folder. This will avoid permission problems.
-* If your making a certificate without a password, the resulting certificate must be kept in a safe place. If this certificate is '''EVER''' disclosed, any data can be decrypted from the server and you must revoke the certificate.
+* If your making a certificate without a password, the resulting certificate must be kept in a safe place. If this certificate is '''EVER''' disclosed, any data can be decrypted from the server and you must revoke the certificate. The newest versions of Apache only allow www and root users to read the key folder by default.
 * Many of the fields when making a certificate authority or server certificate are dated. The ones marked '''(OPTIONAL)''' don't have to be filled in.
-* If copying from the terminal code boxes on this page, there is no need to type the '#', this is where the prompt to type starts on a terminal prompt.
-==Creating a certificate authority==
+== Create an elliptic curve private key ==
-A certificate authority allows you to sign the SSL certificate with some data about yourself and the server. This is created before making the certificate. If you install this certificate authority onto a web browser, it will then accept your certificate as trusted.
 * Open a terminal window.
-* Make a key for the certificate authority. You can choose your cipher by changing the '-aes256' option to your choice. A list of ciphers is available [[OpenSSL ciphers|here]]. Type the following:
+* Type the following into the terminal:
-   # openssl genrsa -aes256 -out ca.key 4096
+   # openssl ecparam -genkey -name prime256v1 -out key.pem
-* Choose and type a password when asked, then retype it for verification. Remember this password for later.
+* '''NOTE:''' This is the private key that must be kept safe. If anyone gets hold of this, they will be able to decrypt your data.
-* Make the certificate authority certificate. You can change the number of days the certificate is valid for by changing the '-days 365' option. Type the following:
-  # openssl req -new -x509 -days 365 -key ca.key -out ca.crt
+== Creating a Certificate Signing Request (CSR) ==
-* You will be asked for the password you used to make the key earlier. Type it in when asked.
+A certificate signing request combines the private key and some information to fill out the certificate with and makes a public key out of this information.
-* Type in a Country code when asked (GB for England).
-* Type in a State or Provence (or County in England) when asked. '''(OPTIONAL)'''
-* Type in a Locality (a town) when asked. '''(OPTIONAL)'''
-* Type in an Organisation name when asked. '''(OPTIONAL)'''
-* Type in an Organisation unit when asked. '''(OPTIONAL)'''
-* Type in a Common name when asked. This is a very important field. Contrary to what the program says, this is not for your name, but the name of the certificate authority. Thinking ahead here, it must not match the common name you want to use for your server certificate. If you want to use similar names for both (for example, in my case 'thinkserver' for the server certificate), it is advisable to append CA to the end of the common name you are using for the certificate authority (thinkserver CA). If you do duplicate the names, you will '''NOT''' be able to create server certificate.
-* Type in an e-mail address when asked. This is the e-mail address people will contact you on if there is a problem with the certificates. Make sure you type an address you would access often enough.
-* After pushing enter on the last option, you will be back at the terminal. Your CA certificate is now ready!
-==Creating a server certificate==
+* Type the following into the terminal:
-* Make a server key. You can choose your cipher by changing the '-aes256' option to your choice. A list of ciphers is available [[OpenSSL ciphers|here]]. Type the following:
+  openssl req -new -key key.pem -out csr.pem
-  # openssl genrsa -aes256 -out server.key 4096
+You will be presented with some options to fill out:
-* Choose and type a password when asked, then retype it for verification. Remember this password for later.
-* Make a server certificate. This is similar to making a certificate authority certificate. You can change the number of days the certificate is valid for by changing the '-days 365' option. Type the following:
-  # openssl req -new -key server.key -out server.csr
-* You will be asked for the password you used to make the key earlier. Type it in when asked.
 * Type in a Country code when asked (GB for England).
 * Type in a State or Provence (or County in England) when asked. '''(OPTIONAL)'''
-* Type in a Locality (a town) when asked. '''(OPTIONAL)'''
+* Type in a Locality (a town or city) when asked. '''(OPTIONAL)'''
-* Type in an Organisation name when asked. '''(OPTIONAL)'''
+* Type in an Organisation name (or company name) when asked. If left blank, it will be filled with 'Internet Widgets Pty'. '''(OPTIONAL)'''
-* Type in an Organisation unit when asked. '''(OPTIONAL)'''
+* Type in an Organisation unit (or department within company) when asked. '''(OPTIONAL)'''
-* Type in a Common name when asked (remember this must be different from the CA common name as explained earlier or it will fail later!)
+* Type in a Common name when asked. This is is usually a FQDN, but can be what you usually how you access the page by (IP address, hostname, or FQDN)
-* Type in an e-mail address when asked.
+* Type in an e-mail address when asked. This is the e-mail address people will contact you on if there is a problem with the certificates. Make sure you type an address you would access often enough.
-* You will be asked two extra options:
+* Type a challenge password (this will stop the private key being accessible, but is not required. If going for simplicity, don't type a password) '''(OPTIONAL)'''
-** A challenge password '''(OPTIONAL)'''
+* Type an optional company name (this is an extra attribute and isn't required) '''(OPTIONAL)'''
-** A company name '''(OPTIONAL)'''
-* After pushing enter on the last option, you will be back at the terminal. Your server certificate is now ready!
-== Signing the server certificate with your certificate authority ==
-* Change the '-set_serial 01' option if you already have a certificate with the same serial number. If you use the same serial number as a certificate already in use or expired, it will cause a serious exception and the web browser will not let you proceed further until this is fixed on the server. Think ahead now! Type the following into the terminal:
-  # openssl x509 -req -days 365 -in server.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out server.crt
-* Type in your password for the certificate authority key when asked.
+== Creating the certificate ==
-* When returned to the terminal, your server certificate is now signed by the certificate authority.
-== Removing the password from the server key ==
+With the private key and the certificate signing request we made earlier, we can now make the certificate.
-The next options will stop Apache asking for the server key password every time your computer restarts or you restart the Apache service. You do not have to do this step, it is your choice and is entirely optional. Remember though, if your server key is then disclosed without a password, your encryption can be decrypted by anybody with the tools - treat the server key with great care!
+* Type the following into the terminal:
-* Type the following:
+ openssl req -x509 -days 365 -rand /dev/urandom -key key.pem -in csr.pem -out cert.pem
-  # openssl rsa -in server.key -out server.key.insecure
+== Securing Apache with created certificate ==
-* Type in your server key password when asked.
+See the following article:
-* The key without a password has the ''insecure'' extension to its file name. The ''insecure'' extension should be removed when it is being implemented on the server.
-== See also ==
+[[Securing Apache with an SSL/TLS certificate]]
-* [[Securing Apache with an SSL/TLS certificate]]
-* [[OpenSSL ciphers]]
 == External Links ==
-Thank you so much to the creators of this page:
+https://msol.io/blog/tech/create-a-self-signed-ecc-certificate/
-http://www.tc.umn.edu/~brams006/selfsign.html
-It would not have been possible to write this article or secure my own server without it! :-)
+Thanks for the information, your site helped us change over to ECDSA!