While Encrypting a File with a Password from the Command Line using OpenSSLis very useful in its own right, the real power of the OpenSSL library is itsability to support the use of public key cryptograph for encrypting orvalidating data in an unattended manner (where the password is not required toencrypt) is done with public keys.
To generate public (e,n) key from the private key using openssl you can use the following command: openssl rsa -in private.pem -out public.pem -pubout To dissect the contents of the private.pem private RSA key generated by the openssl command above run the following (output truncated to labels here). Sep 24, 2014 (1) Generate a Certificate Signing Request (CSR) and new private key. Openssl req -out CSR.csr-new -newkey rsa:2048 -nodes -keyout privateKey.key (2) Generate a self-signed certificate. Openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout privateKey.key-out certificate.crt (3) Create CSR based on an existing private key. Enter CSR and Private Key command. Generate a private key and CSR by running the following command: Here is the plain text version to copy and paste into your terminal: openssl req -new -newkey rsa:2048 -nodes -keyout server.key -out server.csr. Note: Replace “server ” with the domain name you intend to secure. Enter your CSR details. Apr 12, 2020 With openssl self signed certificate you can generate private key with and without passphrase. If you use any type of encryption while creating private key then you will have to provide passphrase every time you try to access private key.
The Commands to Run
Generate a 2048 bit RSA Key
You can generate a public and private RSA key pair like this:
openssl genrsa -des3 -out private.pem 2048
That generates a 2048-bit RSA key pair, encrypts them with a password you provideand writes them to a file. You need to next extract the public key file. You willuse this, for instance, on your web server to encrypt content so that it canonly be read with the private key.
Export the RSA Public Key to a File
This is a command that is
openssl rsa -in private.pem -outform PEM -pubout -out public.pem
The
-pubout
flag is really important. Be sure to include it.Next open the
public.pem
and ensure that it starts with-----BEGIN PUBLIC KEY-----
. This is how you know that this file is thepublic key of the pair and not a private key.To check the file from the command line you can use the
less
command, like this:less public.pem
Do Not Run This, it Exports the Private Key
A previous version of the post gave this example in error.
openssl rsa -in private.pem -out private_unencrypted.pem -outform PEM
The error is that the
-pubout
was dropped from the end of the command.That changes the meaning of the command from that of exporting the public keyto exporting the private key outside of its encrypted wrapper. Inspecting theoutput file, in this case private_unencrypted.pem
clearly shows that the keyis a RSA private key as it starts with -----BEGIN RSA PRIVATE KEY-----
.Visually Inspect Your Key Files
It is important to visually inspect you private and public key files to makesure that they are what you expect. OpenSSL will clearly explain the nature ofthe key block with a
-----BEGIN RSA PRIVATE KEY-----
or -----BEGIN PUBLIC KEY-----
.You can use less to inspect each of your two files in turn:
less private.pem
to verify that it starts with a-----BEGIN RSA PRIVATE KEY-----
less public.pem
to verify that it starts with a-----BEGIN PUBLIC KEY-----
The next section shows a full example of what each key file should look like.
The Generated Key Files
The generated files are base64-encoded encryption keys in plain text format.If you select a password for your private key, its file will be encrypted withyour password. Be sure to remember this password or the key pair becomes useless.
The private.pem file looks something like this:
The public key, public.pem, file looks like:
Protecting Your Keys
Depending on the nature of the information you will protect, it’s important tokeep the private key backed up and secret. The public key can be distributedanywhere or embedded in your web application scripts, such as in your PHP,Ruby, or other scripts. Again, backup your keys!
Remember, if the key goes away the data encrypted to it is gone. Keeping aprinted copy of the key material in a sealed envelope in a bank safety depositbox is a good way to protect important keys against loss due to fire or harddrive failure.
Oh, and one last thing.
If you, dear reader, were planning any funny business with the private key that I have just published here. Know that they were made especially for this series of blog posts. I do not use them for anything else.
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Openssl Show Private Key
When you are dealing with lots of different SSL Certificates, it is quite easy to forget which certificate goes with which Private Key.
Or, for example, which CSR has been generated using which Private Key.
From the Linux command line, you can easily check whether an SSL Certificate or a CSR match a Private Key using the OpenSSL utility.
To make sure that the files are compatible, you can print and compare the values of the SSL Certificate modulus, the Private Key modulus and the CSR modulus.
Cool Tip: Check the expiration date of the SSL Certificate from the Linux command line! The fastest way! Read more → Third generation routing algorithm has the cost function keyed to a door.
Check Compatibility
When you create a Private Key and CSR to obtain an SSL Certificate, OpenSSL generates some internal data called aPrivate Key Definition
modulus.OpenSSL stores the modulus in the Private Key, as well as in the CSR and therefore in the SSL Certificate itself.
If you are using either the incorrect Private Key or the SSL Certificate – you will receive an error as follows: [error] Unable to configure RSA server Private Key [error] SSL Library Error: x509 certificate routines:X509_check_private_key:key values mismatch.
Free guild wars access key generator. So if you got the similar error – it is time to check whatever your Private Key matches the SSL Certificate by comparing their modulus.
[Error] … key values mismatch: Your Private Key and SSL Certificate must contain the same modulus, otherwise the web-server won’t start.
Let’s print the values of the modulus of the Private Key, the SSL Certificate and the CSR with the conversion of them to md5 hashes to make the comparison more convenient.
Print the md5 hash of the SSL Certificate modulus:
Openssl Test Password Private Key
Print the md5 hash of the CSR modulus:
![Advantages of private key encryption Advantages of private key encryption](/uploads/1/2/6/5/126574633/521910642.png)
Print the md5 hash of the Private Key modulus:
Cool Tip: Check the quality of your SSL certificate! Find out its Key length from the Linux command line! Read more →
If the md5 hashes are the same, then the files (SSL Certificate, Private Key and CSR) are compatible.