Creating A Private Root CA to sign the SSL certificates using OpenSSL

Goal of the Document is to demonstrate the step-by-step procedure to create the CA using OpenSSL on Windows and getting the Certificates signed from the CA created.

NOTE:- This can only be used for testing puposes and cannot be used for Production Systems and this would be Private CA and will not be providing Security as provided by Authorised CA bodies.
Step1. Download and setup the open SSL Environment

Download the required binaries from the below link:

http://www.openssl.org/related/binaries.html  which refers you to
http://slproweb.com/products/Win32OpenSSL.html

This link will also offers you to download “Visual C++ 2008 Redistributable for Windows” without which you will not be able to run openssl binaries and will hit the below Error. So download the openssl appropriate for your machine along with the Visual C++ Redistributable   :-



Once Installation is completed you will get the folder name “C:\OpenSSL-Win64” created under C:/ by default. (Name may vary according to the binaries used)
In order to identify the windows to openssl commands set the C:\OpenSSL-Win64\bin in your computer system PATH variable

Step 2 : Create Root CA Certificate and key

Open a DOS Command Prompt
Navigate to the OpenSSL Binaries directory type

cd  C:\OpenSSL-Win64\bin




Create the private key. Type

openssl genrsa -des3 -out PrivateRootCA.key 4096




This will create a Private Key named “RootCA.key”

When prompted enter a *very* strong password

And then verify the password

Create the public key. Type

openssl req -new -x509 -days 365 -key PrivateRootCA.key -out PrivateRootCA.cer




When prompted enter the *very* strong password

For Country Name enter the international standard two letter abbreviation (use GB, NOT UK if in the UK)
For State enter the state name in full, or for IN the county name
For Locality, enter where your company is registered, town or city
For organization name enter either the full company name e.g. Mycompany LTD
For organization unit enter Development or Support
For common name use your domain name e.g mycompany.com
For email address enter a valid address e.g. support@mycompany.com Or you can leave this blank and hit Enter

This will create a Public Key for the root ca named “PrivateRootCA.cer”

Now you are done with creation of a Root CA who can sign your Certificates.

You can verify the Root CA by double clicking on RootCA.cer and you would see Issuer and Owner to be same as below:-







From above screen shots you it can be verified as the Subject Type is CA.

Step3:-  Trusting the New CA in Windows trust Store

In order to use this certificate as trusted certificate for your windows  machine please install the certificate in to your Windows trusted CA list as below:-

1. Double Click on the certificate named RootCA.cer
2. Click on “Install Certificate” button at the bottom in the General Tab




3.You will get below screen and click on “Next”



4.Clicking on the next you will get below screen in this select “Place all certificate in the following store” and in the popup window select “Trusted Root certification Authorities” and click “Ok” and Finsh





5.Once you finish importing the new Trusted Root CA into the store you will get below warning appearing into the windows





Please read through the same and say yes if you are fine with this.If not please do not import the Rot CA into your  Windows trust Store.

Step4:- How to get your Self-Signed certificate Signed from this CA?

Generate a self signed certificate using

keytool -genkey -alias server_cert -keyalg RSA -keypass privatepassword -keystore keystore.jks -storepass password ( create a key pair )

keytool -export -alias server_cert -file self-signed.cer -keystore keystore.jks ( export the certificate from keystore keystore into a file, say self-signed.cer

keytool -certreq -v -alias server_cert -file server.csr -keypass privatepassword -storepass password  -keystore keystore.jks

Once above 3 commands executed you will get three files named

keystore.jks
self-signed.cer
server.csr

Now double click on the file named “self-signed.cer” and click on “Details” Tab inside details tab click on the “Serial number” on the lower box you will find a hex values something like

“‎4f b9 da 8c “ and keep it saved somewhere we would need it in the next step.

Now copy the file named “server.csr” to location “C:\OpenSSL-Win64\bin”

Execute the below command:-

openssl x509 -req -days 365 -in server.csr -CA PrivateRootCA.cer -CAkey PrivateRootCA.key -set_serial 0x4fb9da8c -out server.cer




NOTE:- Please look at the parameter named “-set_serial” which is given a value “0x4fb63530” which is nothing but the Serial Key which we had saved earlier as “4f b6 35 30″ from the self-signed certificate so as to generate the signed-certificate with the same key as we need to import this back to the keystore.It is prefixed with 0x to support the Hex value as 0x is not needed if you  Serial value if in Decimal format.

Once above command is executed successfully you will get a file named “server.cer” created on the same location.

Double Click on the file named “server.cer” and you will see as below:-




Where the things to be noticed are “Issued to” and Issued by” which are showing it as the signed by Private RootCA Ltd.

Now go to “Details” tab and check whether the signed certificate has been generated with the same Serial as self-signed certificate:-



Check in the Certification Path and you would be able to see hierarchy of the certification:-

NOTE:- You might not see the chain directly and would see only one cert in the list that happens because the CA (Our  own created) is not known to windows Trust store so in order to get away with that you would have to add this CA into Windows Trust store. (As mentioned above step-by-step) in Step 3

Step 5:- Importing the Signed Certificate into your Keystore to create a cert-chain  and use the same

Now copy the server.cer and PrivateRootCA.cer file to the location where you have created/generated  your keystore.

Execute below command to import the RootCA.cer certificate into your keystore as this is needed to be present in the keystore before importing the signed certificate.

keytool -import -v -noprompt -trustcacerts -alias rootcacert -file PrivateRootCA.cer -keystore keystore.jks -storepass password




Output Would be as below:-

Certificate was added to keystore
[Storing keystore.jks]

Now import the Signed certificate into your keystore

keytool -import -v -alias server_cert -file server.cer -keystore keystore.jks -keypass privatepassword -storepass password







Output would be as below:-

Certificate reply was installed in keystore
[Storing keystore.jks]

Which implies the Signed certificate had been imported successfully.

Now list the keystore and verify that the certificate chain had been created successfully in the keystore:-

keytool -list -v -keystore keystore.jks  -alias server_cert  -storepass password

You would see the output as below:-

D:\keystore>keytool -list -keystore keystore.jks -v -alias server_cert
Enter keystore password:
Alias name: server_cert
Creation date: May 21, 2012
Entry type: PrivateKeyEntry
Certificate chain length: 2
Certificate[1]:
Owner: CN=My.Machine.Host.Name, OU=Support, O=Oracle, L=KA, ST=Ban, C=IN
Issuer: CN=Private RootCA Ltd., OU=Support, O=Oracle, L=BAN, ST=KA, C=IN
Serial number: 4fb9da8c
Valid from: Mon May 21 11:44:04 IST 2012 until: Tue May 21 11:44:04 IST 2013
Certificate fingerprints:
MD5:  5F:FF:6F:8A:C5:22:3D:51:23:A8:FF:AF:96:5A:98:BB
SHA1: 29:4A:14:5A:42:31:57:94:57:3A:CA:B4:E2:AB:00:90:D5:69:96:1C
Signature algorithm name: SHA1withRSA
Version: 1
Certificate[2]:
Owner: CN=Private RootCA Ltd., OU=Support, O=Oracle, L=BAN, ST=KA, C=IN
Issuer: CN=Private RootCA Ltd., OU=Support, O=Oracle, L=BAN, ST=KA, C=IN
Serial number: 9126d09b3c5e8c3c
Valid from: Mon May 21 11:40:41 IST 2012 until: Tue May 21 11:40:41 IST 2013
Certificate fingerprints:
MD5:  7A:8E:2A:3B:19:51:8C:F7:B3:3A:31:CE:78:30:DF:E6
SHA1: B7:7D:58:B2:85:EC:44:15:FB:78:F6:B3:4E:A3:AD:A4:25:5C:B4:C2
Signature algorithm name: SHA1withRSA
Version: 3Extensions:
#1: ObjectId: 2.5.29.14 Criticality=false
SubjectKeyIdentifier [
KeyIdentifier [
0000: 99 A1 64 8D 58 58 2F AE   05 04 4B 3D C4 35 EA 39  ..d.XX/...K=.5.9
0010: 04 E3 8F 7F                                        ....
]
]
#2: ObjectId: 2.5.29.19 Criticality=false
BasicConstraints:[
CA:true
PathLen:2147483647
]
#3: ObjectId: 2.5.29.35 Criticality=false
AuthorityKeyIdentifier [
KeyIdentifier [
0000: 99 A1 64 8D 58 58 2F AE   05 04 4B 3D C4 35 EA 39  ..d.XX/...K=.5.9
0010: 04 E3 8F 7F                                        ....
]
]
D:\keystore>

Where you can see the Certificate[1] as your server certificate and Certificate[2] as RootCA certificate who signed the certificate.

Step 6:- Configuring and using the Keystore and Certificates created

From the Admin console, go to your server page, and in the Keystore&SSL tab choose:
Custom Identity and Custom Trust
Custom Identity
Custom Identity Key Store File Name:  keystore.jks
Custom Identity Key Store Type: jks
Custom Identity Key Store Pass Phrase:  password
Confirm Custom Identity Key Store Pass Phrase: password
Custom Trust
Custom Trust Key Store File Name:  keystore.jks
Custom Trust Key Store Type: jks
Custom Trust Key Store Pass Phrase:  password
Confirm Custom Trust Key Store Pass Phrase: password
Private Key Alias: server_cert
Passphrase: password  privatepassword
Confirm Passphrase:   privatepassword

Ensure that SSL Listen Port Enabled is selected, then restart your server.
You are done.
WebLogic is now configured successfully to do one-way SSL (no client authentication).