Keytool Utility:
Generate your multi-domain certificates with OpenSSL and not with keytool then convert key and certificate to a Java Keystore to use with Tomcat. The following example generates a self-signed certificate, it should be easy enough to adapt for a 'real' certificate. Open a command prompt in the same directory as Java keytool; alternatively, you may specify the full path of keytool in your command. Pay close attention to the alias you specify in this command as it will be needed later on. Keytool -genkey -alias mydomain -keyalg RSA -keystore KeyStore.jks -keysize 2048 2. Generate a CSR based on the new. How to Generate a CSR for Tomcat The following instructions will guide you through the CSR generation process on Tomcat. To learn more about CSRs and the importance of your private key, reference our Overview of Certificate Signing Request article.
Keytool is a key and certificate management JDK utility which helps in managing a keystore of private/public keys and associated certificates. It allows users to administer their own public/private key pairs and associated certificates for use in self-authentication (where the user authenticates himself/herself to other users/services) or data integrity and authentication services, using digital signatures. It also allows users to cache the public keys (in the form of certificates) of their communicating peers.
Java Keytool stores the keys and certificates in what is called a keystore. Java keystore is implemented as a file by default. It protects private keys with a password.
keytool also enables users to administer secret keys used in symmetric encryption/decryption (e.g. RSA,DES).
A Keytool keystore contains the private key and any certificatesnecessary to complete a chain of trust and establish the trustworthiness of the primary certificate.
All certificates in a Java keystore is associated with a unique alias. Which will be used as a pointer to later perform any of the keytool operation to import/export/delete/change certificates/key etc.
Keytool Options:
The various keytool options are listed below
KEYTOOL OPTIONS | DESCRIPTION |
-delete | Deletes an entry from the Keystore |
-exportcert | Exports a certificate from a Keystore |
-genkeypair | Generates a key pair |
-genseckey | Generates a secret key pair |
-gencert | Generates a certificate from a certificate request |
-importcert | Import a certificate or a certificate chain to keystore |
-importpass | Imports a password |
-importkeystore | Imports one or all entries from another keystore to a keystore |
-keypasswd | Changes the key password of an entry in keystore |
-list | Lists entries in a keystore |
-printcert | Prints the content of a certificate |
-printcertreq | Prints the content of a certificate request |
-printcrl | Prints the content of a CRL file |
-storepasswd | Changes the store password of a keystore |
Various Steps to process the Keystore , CSR and the signed certificate.
Create a keystore which contains private key
Generate a CSR (Certificate Signing Request) from keystore
Generate Signed Primary/Server Certificate from Certificate Authority
Import the Primary/Server certificate, root and intermediate CA certificates to keystore.
Share the certificate or root certificates to system which use the SSL to communicate to your system/application.
Create a keystore using Keytool:
While we create a Java keystore we will first create the .jks file that will initially only contain the private key using keytool utility.
-alias is an option to mention an Alias Name to your key entry
-keyalgspecifies the algorithm to be used to generate the key pair
-keysizespecifies the size of each key to be generated.
-sigalg specifies the algorithm that should be used to sign the self-signed certificate; this algorithm must be compatible with keyalg.
–validityspecifies the validity of the keystore which you want to create.
When you execute the command we will be prompted with question which we need answer to add as the key details such as Common Name(website/Application dns name), Organisation, Country,State, province, Country code etc. This is user defined values. Also it will be prompt you to enter keystore and key password which should be used in future to read/write/modify the keystore.
As the keystore name is mentioned keystore.jks while creating keystore.jks file will be created in the current folder.
![Keytool Generate Csr And Key Keytool Generate Csr And Key](/uploads/1/2/5/8/125872516/261565305.png)
Use below command to list the entries in keystore to view the content. We will be able to see the entered values reflected on the private key entries on the keystore.jks file.
Generate a CSR (Certificate Signing Request) from keystore:
Next step is to create a Certificate Signing Request(CSR) from the created keystore to share with Certificate Authority(CA) to sign and generate the Primary/Server certificate.
We need to pass the correct alias name and password which we mentioned during the creation of the keystore to extract the certificate request.
Generate Signed Primary/Server Certificate from Certificate Authority
Submit the generated CSR to any of the CA authority which is supported by the SSL community to get the signed the Primary/Server certificate. The CA authority will be selected based on the organisations or your personnel selection.
Top 10 Certificate Authority in the world (Info based on 2017 from wikipedia)
Rank | Issuer |
1 | Comodo |
2 | IdenTrust |
3 | Symantec |
4 | GoDaddy |
5 | GlobalSign |
6 | DigiCert |
7 | Certum |
8 | Entrust |
9 | Secom |
10 | Actalis |
Import the Primary/Server certificate, root and intermediate CA certificates to keystore
Once the CA signed the certificate and share it with us, we need to import the certificate to the keystore for the privatekey entry we created.
Below keytool commands can be used to import the signed certificate to keystore, we should use the alias name same as the alias name on the private key entry.
Second one is optional using -trustcacerts.
If the –trustcacerts option has been specified, additional certificates are considered for the chain of trust, namely the certificates in a file named “cacerts”
If the alias does not point to a key entry, then keytool assumes you are adding a trusted certificate entry. In this case, the alias should not already exist in the keystore. If the alias does already exist, then keytool outputs an error, since there is already a trusted certificate for that alias, and does not import the certificate.
If the alias points to a key entry, then keytool assumes you are importing a certificate reply.
The old chain can only be replaced if a valid keypass, the password used to protect the private key of the entry, is supplied. If no password is provided, and the private key password is different from the keystore password, the user will be prompted for it.
Import a root or intermediate CA certificate to an existing Java keystore
entrust(CA) is used as an example, File will be different and supplied by the Certificate Authority(CA) based on your CA.
To View/List the certificate we have added below command can be used
Share the certificate or root certificates to system which use the SSL to communicate to your system/application.
As you have created a new Private/Public key for you DNS name we need to share the certificate with any of the interfacing applications (Not Browser as it will be having CA root/intermediate on its list).
Important commands for keytool which can be used while create/import/export/delete/change certificate in a keystore.
- Generate a Java keystore and key pair:
- Generate a certificate signing request (CSR) for an existing Java keystore:
- Generate a keystore and self-signed certificate:
- View/List the certificate we have added below command can be used
- Import a root or intermediate CA certificate to an existing Java keystore
- Delete a certificate from a Java Keytool keystore
- Change a Java keystore password
- Export a certificate from a keystore
SSL Certificate CSR Creation for Java Based Web Servers.
If you already have your SSL Certificate and just need to install it, see
SSL Certificate Installation :: Java Web Servers.
SSL Certificate Installation :: Java Web Servers.
How to generate a CSR using Java Keytool
Keytool Export Csr From Keystore
**NOTE: You must generate a new keystore through this process. If you try to install a new certificate to an old keystore your certificate will not work properly. Backup and remove any old keystores if necessary before beginning this process.
Recommended: Save yourself some time by using our new Java Keytool CSR Wizard to create your CSR with Keytool. Just fill in the details, click Generate, and paste your customized keytool command into your terminal.
If you prefer to roll your own keytool commands to generate your CSR, just follow our old instructions below:
Create a New Keystore
- You will be using the keytool command to create your new key-CSR pairing. Enter the following:
keytool -genkey -alias server -keyalg RSA -keysize 2048 -keystore yourdomain.jks
'Yourdomain' is the name of the domain you are securing. However, if you are ordering a Wildcard Certificate, do not include * in the beginning of the filename as this is not a valid filename character. - You will be prompted for the DN information. Please note: when it asks for first and last name, this is not YOUR first and last name, but rather your domain name and extension(i.e., www.yourdomain.com). If you are ordering a Wildcard Certificate this must begin with *. (example: *.digicert.com)
- Confirm that the information is correct by entering 'y' or 'yes' when prompted. Next you will be asked for your password to confirm. Make sure to remember the password you choose.
Generate Your CSR with Your New keystore
- Next, use keytool to actually create the Certificate Signing Request. Enter the following:
keytool -certreq -alias server -keyalg RSA -file yourdomain.csr -keystore yourdomain.jks
Again, 'yourdomain' is the name of the domain you are securing. (without the * character if you are ordering a Wildcard Certificate). - Enter the keystore password.
- Then the SSL Certificate CSR file is created. Open the CSR with a text editor, and copy and paste the text (including the BEGIN and END tags) into the DigiCert web order form.
- After you receive your SSL Certificate from DigiCert, you can install it.See SSL Certificate Installation :: Java Web Servers.
Generating a CSR for Issuance of an SSL Certificate with Keytool
Keytool Generate Csr And Key Generator
How to generate a Certificate Signing Request for your Java Web Server