X.509 certificates are used as a key storage: Instead of keeping SSH keys in a proprietary format, the software keeps the keys in X.509 certificates. When the SSH key exchange is done, the keys are taken from the certificates. Benefits of Using X.509 Certificates. Ssh-keygen -t rsa -b 4096 -C 'RSA 4096 bit Keys' Generate an DSA SSH keypair with a 2048 bit private key. Ssh-keygen -t dsa -b 1024 -C 'DSA 1024 bit Keys' Generate an ECDSA SSH keypair with a 521 bit private key. Ssh-keygen -t ecdsa -b 521 -C 'ECDSA 521 bit Keys' Generate an ed25519 SSH keypair- this is a new algorithm added in OpenSSH.
With ssh-keygen. Ssh-keygen -t rsa -b 2048 -f dummy-ssh-keygen.pem -N ' -C 'Test Key' Converting DER to PEM. If you have an RSA key pair in DER format, you may want to convert it to PEM to allow the format conversion below: Generation: openssl genpkey -algorithm RSA -out genpkey-dummy.cer -outform DER -pkeyopt rsakeygenbits:2048 Conversion. Yes, it is possible to use x509 certificates with ssh, but this is a very esoteric configuration and you are way out of your depth here. An x509 certificate is a signed public key along with prescribed meta-data presented in a prescribed format. You don't need to sign it.
If you have a PKI certificate in your Windows PC that you would like to use to log in to your OpenSSH-enabled Linux server, it can be a pain to figure out how to extract the public key from this file and convert it into a format OpenSSH can understand. To start with, we need to find the certificate to use, which is located in the Microsoft Certificate Store. A quick and dirty way to see your certificates is to go into Internet Explorer, find the Internet Options, go to the Content tab, and click on Certificates. Once you locate the certificate you want to use to log in to your OpenSSH server, select it and click the Export… button at the bottom of the Certificates dialog box. This will start the Certificate Export Wizard.
Follow the options below to complete the wizard.
- Do NOT export the private key
- Format: DER encoded binary X.509 (.CER)
Now that you have an exported public certificate/key pair, you need to copy this file to your Linux system. You can either do a file copy or open the new certificate file in a text editor and copy the text contents and paste them in a new file in the Linux system. Execute the following command in your Linux system to extract just the public key from your DER-encoded certificate:
$ openssl x509 -in joscor.crt -pubkey -noout > joscor.pub.tmp
Now that you have the public key extracted, it needs to be converted into PKCS#8 OpenSSH format (as it’s currently in OpenSSL format).
$ ssh-keygen -f joscor.pub.tmp -i -m PKCS8 > joscor.pub
Now we have a winner! This file now contains the information to place into your .ssh/authorized_keys file to allow users to authenticate into your OpenSSH server. If you need help with this part or if you’re looking to take security to the next step with the WWPass PassKey hardware token, please refer to the following article: Securing OpenSSH with WWPass PassKey
Overview
The following is an extremely simplified view of how SSL is implemented and what part the certificate plays in the entire process.
Normal web traffic is sent unencrypted over the Internet. That is, anyone with access to the right tools can snoop all of that traffic. Obviously, this can lead to problems, especially where security and privacy is necessary, such as in credit card data and bank transactions. The Secure Socket Layer is used to encrypt the data stream between the web server and the web client (the browser).
SSL makes use of what is known as asymmetric cryptography, commonly referred to as public key cryptography (PKI). With public key cryptography, two keys are created, one public, one private. Anything encrypted with either key can only be decrypted with its corresponding key. Thus if a message or data stream were encrypted with the server's private key, it can be decrypted only using its corresponding public key, ensuring that the data only could have come from the server.
If SSL utilizes public key cryptography to encrypt the data stream traveling over the Internet, why is a certificate necessary? The technical answer to that question is that a certificate is not really necessary - the data is secure and cannot easily be decrypted by a third party. However, certificates do serve a crucial role in the communication process. The certificate, signed by a trusted Certificate Authority (CA), ensures that the certificate holder is really who he claims to be. Without a trusted signed certificate, your data may be encrypted, however, the party you are communicating with may not be whom you think. Without certificates, impersonation attacks would be much more common.
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.
Sophos system extension blocked. Boundless download free. 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:
Ssh Client X509
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
Step 5: Installing the Private Key and Certificate
When Apache with mod_ssl is installed, it creates several directories in the Apache config directory. The location of this directory will differ depending on how Apache was compiled. Lscwp.
cp server.crt /usr/local/apache/conf/ssl.crt
cp server.key /usr/local/apache/conf/ssl.key
Step 6: Configuring SSL Enabled Virtual Hosts
SSLEngine on
SSLCertificateFile /usr/local/apache/conf/ssl.crt/server.crt
SSLCertificateKeyFile /usr/local/apache/conf/ssl.key/server.key
SetEnvIf User-Agent '.*MSIE.*' nokeepalive ssl-unclean-shutdown
CustomLog logs/ssl_request_log
'%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x '%r' %b'
Step 7: Restart Apache and Test
Ssh-keygen X509
/etc/init.d/httpd stop
/etc/init.d/httpd stop
Ssh Vs X509
https://public.akadia.com