Https SSL Knowledge & how to get a self-signed certificate on ubuntu.

Https and SSL are based on encryption of Public key and Private key.

The certificate is kind of the public key, while the private key is used to encrypt the information that client transfers.The private key is saved on the side of websites.

To get a self signed certificate on ubuntu, you need to install openssl first.

sudo apt-cache search libssl
#Use the command above to find the lastest version of libssl. I got "libssl0.9.8" in the result
 

sudo apt-get installl libssl0.9.8

After install libssl, follow the steps below (copy from http://www.akadia.com/services/ssh_test_certificate.html):

Step 1: Generate a Private Key

The openssl toolkit is used to generate an RSA Private Key and CSR (Certificate Signing Request). It can also be used to generate self-signed certificates which can be used for testing purposes or internal usage.

The first step is to create your RSA Private Key. This key is a 1024 bit RSA key which is encrypted using Triple-DES and stored in a PEM format so that it is readable as ASCII text.

openssl genrsa -des3 -out server.key 1024

Generating RSA private key, 1024 bit long modulus
.........................................................++++++
........++++++
e is 65537 (0x10001)
Enter PEM pass phrase:
Verifying password - Enter PEM pass phrase:

Step 2: Generate a CSR (Certificate Signing Request)

Once the private key is generated a Certificate Signing Request can be generated. The CSR is then used in one of two ways. Ideally, the CSR will be sent to a Certificate Authority, such as Thawte or Verisign who will verify the identity of the requestor and issue a signed certificate. The second option is to self-sign the CSR, which will be demonstrated in the next section.

During the generation of the CSR, you will be prompted for several pieces of information. These are the X.509 attributes of the certificate. One of the prompts will be for "Common Name (e.g., YOUR name)". It is important that this field be filled in with the fully qualified domain name of the server to be protected by SSL. If the website to be protected will be https://public.akadia.com, then enter public.akadia.com at this prompt. The command to generate the CSR is as follows:

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

Country Name (2 letter code) [GB]:CH
State or Province Name (full name) [Berkshire]:Bern
Locality Name (eg, city) [Newbury]:Oberdiessbach
Organization Name (eg, company) [My Company Ltd]:Akadia AG
Organizational Unit Name (eg, section) []:Information Technology
Common Name (eg, your name or your server's hostname) []:public.akadia.com
Email Address []:martin dot zahn at akadia dot ch
Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

Step 3: Remove Passphrase from Key

One unfortunate side-effect of the pass-phrased private key is that Apache will ask for the pass-phrase each time the web server is started. Obviously this is not necessarily convenient as someone will not always be around to type in the pass-phrase, such as after a reboot or crash. mod_ssl includes the ability to use an external program in place of the built-in pass-phrase dialog, however, this is not necessarily the most secure option either. It is possible to remove the Triple-DES encryption from the key, thereby no longer needing to type in a pass-phrase. If the private key is no longer encrypted, it is critical that this file only be readable by the root user! If your system is ever compromised and a third party obtains your unencrypted private key, the corresponding certificate will need to be revoked. With that being said, use the following command to remove the pass-phrase from the key:

cp server.key server.key.org
openssl rsa -in server.key.org -out server.key

The newly created server.key file has no more passphrase in it.

-rw-r--r-- 1 root root 745 Jun 29 12:19 server.csr
-rw-r--r-- 1 root root 891 Jun 29 13:22 server.key
-rw-r--r-- 1 root root 963 Jun 29 13:22 server.key.org

Step 4: Generating a Self-Signed Certificate

At this point you will need to generate a self-signed certificate because you either don't plan on having your certificate signed by a CA, or you wish to test your new SSL implementation while the CA is signing your certificate. This temporary certificate will generate an error in the client browser to the effect that the signing certificate authority is unknown and not trusted.

To generate a temporary certificate which is good for 365 days, issue the following command:

openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
Signature ok
subject=/C=CH/ST=Bern/L=Oberdiessbach/O=Akadia AG/OU=Information
Technology/CN=public.akadia.com/Email=martin dot zahn at akadia dot ch
Getting Private key

The certificate you get can used on both linux and windows. You can double click the crt file on Windows and add it to "the trusted root CA", and your website can be visited through the https protocol.

I use web.py to build my site.To enable the https mode:http://webpy.org/cookbook/ssl