OpenSSL - useful commands. Last updated: 14/06/2018. How to use OpenSSL? OpenSSL is the true Swiss Army knife of certificate management, and just like with the real McCoy, you spend more time extracting the nail file when what you really want is the inflatable hacksaw. You'll find an overview of the most commonly used commands below. Certificate requests and key generation. Typically, when you. With its core library written in C programming language, OpenSSL commands can be used to perform hundreds of functions ranging from the CSR generation to converting certificate formats. But for someone who just wants to install an SSL certificate, only a handful of commands are really necessary $ openssl rand -base64 9 Emo+xQINmYoU [ Get this free book from Red Hat and O'Reilly - Kubernetes Operators: Automating the Container Orchestration Platform. ] Wrap up. In this article, you learned some basic OpenSSL commands that can make your daily life as a systems administrator easier. OpenSSL is a very powerful suite of tools (and software.
openssl req -text -noout -verify -in server.csr Verify a certificate and key matches. These two commands print out md5 checksums of the certificate and key; the checksums can be compared to verify that the certificate and key match. openssl x509 -noout -modulus -in server.crt| openssl md5 openssl rsa -noout -modulus -in server.key| openssl md Erstellen, Verwalten und Konvertieren von SSL-Zertifikaten mit OpenSSL. Einer der beliebtesten Befehle in SSL an erstellen, konvertieren, verwalten the SSL-Zertifikate ist OpenSSL. Es wird viele Situationen geben, in denen Sie auf verschiedene Weise mit OpenSSL umgehen müssen, und hier habe ich sie für Sie als praktischen Spickzettel aufgelistet OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) network protocols and related cryptography standards required by them. The openssl program is a command line tool for using the various cryptography functions of OpenSSL's crypto library from the shell. It can be used fo In this article, I will take you through 25+ Popular Examples of Openssl Commands in Linux. openssl is an opensource command line tool in linux primarliy used to generate ssl certificate with the help of private key and certificate signing request(CSR) file. This tool will use OpenSSL Library to implement its tasks.In most of the Linux systems, this tool will be installed by default
openssl s_client showcerts openssl s_client -connect example.com:443 -showcerts. The showcerts flag appended onto the openssl s_client connect command prints out and will show the entire certificate chain in PEM format, whereas leaving off showcerts only prints out and shows the end entity certificate in PEM format. Other than that one difference, the output is the same .1) OpenSSL - Certificate content. You can use the same command to view SAN (Subject Alternative Name) certificate as well. Conclusion. In this tutorial we learned about openssl commands which can be used to view the content of different kinds of certificates. I have kept the tutorial short and crisp keeping to the point, you may check other. Create, Manage & Convert SSL Certificates with OpenSSL One of the most popular commands in SSL to create, convert, manage the SSL Certificates is OpenSSL. There will be many situations where you have to deal with OpenSSL in various ways, and here I have listed them for you as a handy cheat sheet
The toolkit is loaded with tons of functionalities that can be performed using various options. As a Linux administrator, you must know openssl commands to secure your network, which includes testing POP, IMAP servers, https certificates, generating self signed keys, benchmarking speeds et OpenSSL ist als Freeware kostenlos erhältlich und lässt sich unter anderem unter Windows 32/64-Bit, Mac OS X, Linux sowie OS2 nutzen. Bei Linux ist OpenSSL in der Regel enthalten oder über die..
The openssl commands typically have options -inform DER or -outform DER to specify that the input or output file is DER respectively. So for example the command to convert a PKCS8 file to a traditional encrypted EC format in DER is the same as above, but with the addition of -outform DER OpenSSL is an open-source command line tool that is commonly used to generate private keys, create CSRs, install your SSL/TLS certificate, and identify certificate information. We designed this quick reference guide to help you understand the most common OpenSSL commands and how to use them Viewing your SSL Certificate information with OpenSSL commands. To view the contents of any X.509 certificate use the following command: openssl x509 -text -in yourdomain.crt -noout Verifying Keys match with OpenSSL commands. Sometimes you need to make sure that your key pairs match. Using the following commands generates a hash of the output for your CSR, Private Key and Certificate. You need to compare the values, and if they match you know that your key pairs match, too
req - Command passed to OpenSSL intended for creating and processing certificate requests usually in the PKCS#10 format.-x509 - This multipurpose command allows OpenSSL to sign the certificate somewhat like a certificate authority. X.509 refers to a digitally signed document according to RFC 5280. -sha256 - This is the hash to use when encrypting the certificate.-nodes - This command is for no. . After that type version to get the installed OpenSSL version on your system OpenSSL is avaible for a wide variety of platforms. can be downloaded from www.openssl.org. A windows distribution can be found This tutorial shows some basics funcionalities of the OpenSSL command line tool. After the installation has been completed you should able to check for the version
The OpenSSL s_server command below implements a generic SSL/TLS server. It should be used for test purposes only. The example below listens for connections on port 8080 and returns an HTML formatted status page that includes lots of information about ciphers. openssl s_server -key key.pem -cert cert.pem -accept 8080 -www . Run an SSL server that supports SNI. The OpenSSL s_server command below. OpenSSL libraries and algorithms can be used with openssl command. In this tutorial we will look different use cases for openssl command. Private Key. Private keys should kept secret. Private keys generally used to decrypt data. Public Key. Public keys are provided every one and it not secret. Public keys generally used to encrypt data. Certificate. Certificates holds keys and related.
The openssl command-line binary that ships with the OpenSSL libraries can perform a wide range of cryptographic operations. It can come in handy in scripts or for accomplishing one-time command-line tasks. Documentation for using the openssl application is somewhat scattered , however, so this article aims to provide some practical examples of its use. I assume that you've already got a. OpenSSL tips and common commands. OpenSSL is the de-facto tool for SSL on linux and other server systems. It providers both the library for creating SSL sockets, and a set of powerful tools for administrating an SSL enabled website. Following are a few common tasks you might need to perform with OpenSSL. Generate a certificate request. Obtaining a signed SSL certificate envolves a number of.
OpenSSL is a powerful cryptography toolkit that can be used for encryption of files and messages. If you want to use the same password for both encryption of plaintext and decryption of ciphertext, then you have to use a method that is known as symmetric-key algorithm. From this article you'll learn how to encrypt and decrypt files and messages with a password from the Linux command line. In this article you'll find how to generate CSR (Certificate Signing Request) using OpenSSL from the Linux command line, without being prompted for values which go in the certificate's subject field.. Below you'll find two examples of creating CSR using OpenSSL.. In the first example, i'll show how to create both CSR and the new private key in one command
if you have Git for Windows, type bash in terminal then you can use openssl command vola - Ali Karaca Feb 4 '20 at 9:44. 1. type Git in Windows Search bar and you get all the related listing. Then click on Git Bash, then you are in bash shell. - Kartik Javali Mar 3 at 16:43 | Show 1 more comment. 54. If you have chocolatey installed you can install openssl via a single command i.e. choco. Access IMAP server from the command line using OpenSSL. In this post, we'll use OpenSSL to gain access to an IMAP mail server. The mail server we'll use is Google's GMail. If you are running Linux, you should have openssl installed. On Windows, obtain and install the Win32 version of OpenSSL. If your IMAP server does not support SSL, you can use the excellent netcat utility on Linux. The OpenSSL command below presents a readable version of the generated certificate: openssl x509 -in myserver.crt -text -noout. Here's part of the output for the self-signed certificate: Certificate: Data: Version: 3 (0x2) Serial Number: 13951598013130016090 (0xc19e087965a9055a) Signature Algorithm: sha256WithRSAEncryption Issuer: C=US, ST=Illinois, L=Chicago, O=Faulty Consulting, OU=IT, CN.
You can use the same openssl for that. To connect to a remote host and retrieve the public key of the SSL certificate, use the following command. $ openssl s_client -showcerts -connect ma.ttias.be:443. This will connect to the host ma.ttias.be on port 443 and show the certificate. It's output looks like this . It can be used for. creation of key parameters; creation of X.509 certificates, CSRs and CRLs; calculation of message digests; encryption and decryption; SSL/TLS client and server tests; handling of S/MIME signed or encrypted mail ; and more... Download For Production Use. Source code. The basic command to use is openssl enc plus some options: -P — Print out the salt, key and IV used, then exit. -k <secret> or -pass pass:<secret> — to specify the password to use. -aes-256-cbc — the cipher name. $ openssl enc -nosalt -aes-256-cbc -k hello-aes -P key= C639A572E14D5075C52EF3D2710AF9F359DD4 iv. Due to a bug in OpenSSL, at the time of writing session resumption testing doesn't work in combination with TLS 1.3. Until the bug is resolved, 31 the best you can do is test the earlier protocol versions. Use the -no_tls1_3 switch. The previous command will produce a sea of output, most of which you won't care about Run the following OpenSSL command to generate your private key and public certificate. Answer the questions and enter the Common Name when prompted. Validate your P2 file. In the Cloud Manager, click TLS Profiles. Click Add, and enter values in the Display Name, Name, and optionally, Description fields. In the Present Certificate section, click.
General OpenSSL Commands. These are the set of commands that allow the users to generate CSRs, Certificates, Private Keys and many other miscellaneous tasks. Here, we have listed few such commands: (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. OpenSSL: Zertifikat erstellen - so geht's. Unter Linux können Sie mit OpenSSL in wenigen Minuten Ihr eigenes SSL-Zertifikat erstellen. Wie Sie dazu vorgehen müssen, erfahren Sie in diesem Praxistipp. Für Links auf dieser Seite erhält CHIP ggf. eine Provision vom Händler, z.B. für solche mit -Symbol openssl list-standard-commands Check out the official OpenSSL docs for explanations of the standard commands. To view the many secret key algorithms available in OpenSSL, use: openssl list-cipher-commands Now, let's try some encryption. If you wanted to encrypt the text Hello World! with the AES algorithm using CBC mode and a 256-bit key, you would do as follows: touch plain.txt echo Hello. By default, OpenSSL for Windows is installed in the following directory: if you have installed Win64 OpenSSL v1.X.X: C:\Program Files\OpenSSL-Win64\ if you have installed Win32 OpenSSL v1.X.X: C:\Program Files (x86)\OpenSSL-Win32\ To launch OpenSSL, open a command prompt with administrator rights OpenSSL Console OpenSSL Commands to Convert Certificate Formats. If you have got certificate files from the CA which are not supported on your web server, then you can convert your certificate files into the format your web server or hosting provider requires using OpenSSL commands. To know about all the commands, apply the help command. Openssl> help To get help on a particular command, use.
Close OpenSSL. Open a Command Prompt (CMD) as Administrator; Run the following command: SET OPENSSL_CONF=C:\OpenSSL-Win32\bin\openssl.cfg; Reboot the computer. Need help? SSL Help Wizard SSL Certificate Wizard Call us +31 88 775 775 0. Send us a message SSLCheck. Our SSLCheck will examine your website's root and intermediate certificates for correctness and report any potential issues. Generate OpenSSL Private Key. Firstly, run the command below to generate and save your private key which will be used to sign the SSL certificate. You can use anything in place of ubuntu_server. $ openssl genrsa -out ubuntu_server.key Generate OpenSSL Private Key. Your private key will be saved in the current working directory. Generate Certificate Signing Request. Next, generate a Certificate. Basic OpenSSL Commands. The following section of the guide presents some of the more common basic commands, and parameters to commands which are part of the OpenSSL toolkit. For additional information, read the various OpenSSL system manual pages with the man command, and refer to the information presented in the Resources section of this guide. Determine installed OpenSSL version: openssl. This OpenSSL command will generate a parameter file for a 256-bit ECDSA key: openssl genpkey -genparam -algorithm ec -pkeyopt ec_paramgen_curve:P-256 -out ECPARAM.pem. openssl genpkey runs openssl's utility for private key generation.-genparam generates a parameter file instead of a private key. You could also generate a private key, but using the parameter file when generating the key and. OpenSSL CSR Wizard. Our OpenSSL CSR Wizard is the fastest way to create your CSR for Apache (or any platform) using OpenSSL. Fill in the details, click Generate, then paste your customized OpenSSL CSR command in to your terminal.. Note: After 2015, certificates for internal names will no longer be trusted
Enter openssl version and see the result. Important note: if you already had a command prompt open, you will need to close and reopen in order for this to work. Michael Galloway thank you for this. You likely want to use gpg instead of openssl so see Additional Notes at the end of this answer. But to answer the question using openssl: To Encrypt: openssl enc -aes-256-cbc -in un_encrypted.data -out encrypted.data To Decrypt: openssl enc -d -aes-256-cbc -in encrypted.data -out un_encrypted.dat OpenSSL is a powerful cryptography toolkit. Many of us have already used OpenSSL for creating RSA Private Keys or CSR (Certificate Signing Request). However, did you know that you can use OpenSSL to benchmark your computer speed or that you can also encrypt files or messages? This article will provide you with some simple to follow tips on how to encrypt messages and files using OpenSSL. This command returns information about the connection including the certificate, and allows you to directly input HTTP commands. # openssl s_client -connect server :443 -CAfile cert.pem Convert a root certificate to a form that can be published on a web site for downloading by a browser
So by using the common syntax for OpenSSL subject written via command line you need to specify all of the above (the OU is optional) and add another section called subjectAltName=. By adding DNS.n (where n is a sequential number) entries under the subjectAltName field you'll be able to add as many additional alternate names as you want, even not related to the main domain. Obvio openssl s_client -connect <hostname>:<port>-tls1-cipher: Forces a specific cipher. This option is useful in testing enabled SSL ciphers. Use the openssl ciphers command to see a list of available ciphers for OpenSSL While Encrypting a File with a Password from the Command Line using OpenSSL is very useful in its own right, the real power of the OpenSSL library is its ability to support the use of public key cryptograph for encrypting or validating data in an unattended manner (where the password is not required to encrypt) is done with public keys. The Commands to Run Generate a 2048 bit RSA Key. You can. . You can take advantage of these features to quickly write Bash (Bourne-Again Shell) scripts that automate tasks, such as testing SSL/TLS (Secure Socket Layer/Transport Layer Security) connections. Step 3: Generate a Certificate Signing Request (CSR) using OpenSSL on Windows. In Windows, click Start > Run. In the Open box, type CMD and click OK. A command prompt window appears. Type the following command at the prompt and press Enter: cd \OpenSSL-Win32\bin. The line changes to C:\OpenSSL-Win32\bin. Type the following command at the prompt.
# # Filename: openssl-www.example.org.conf # # Sample openssl configuration file to generate a key pair and a PKCS#10 CSR # with included requested SubjectAlternativeNames (SANs) # # Sample openssl commandline command: # # openssl req -config ./openssl-www.example.org.conf -new -keyout www.example.org-key.pem -out www.example.org-csr.pem # # To remove the passphrase from the private key file. The number of sub-commands and options for the openssl command is rather daunting. However, there are a few key commands and patterns which I use most often and find very handy. 1. Generating a New CSR and Key. When generating (or regenerating) a SSL certificate, the first step is to create a new CSR (certificate signing request) with a new public/private key pair: openssl req -nodes -new. Win32 OpenSSL v1.1.1k Light EXE | MSI: 3MB Installer: Installs the most commonly used essentials of Win32 OpenSSL v1.1.1k (Only install this if you need 32-bit OpenSSL for Windows. Note that this is a default build of OpenSSL and is subject to local and state laws. More information can be found in the legal agreement of the installation
Before you start OpenSSL, you need to set 2 environment variables: set RANDFILE=c:\demo\.rnd set OPENSSL_CONF=C:\OpenSSL-Win32\bin\openssl.cfg. Now you can start OpenSSL, type: c:\OpenSSL-Win32\bin\openssl.exe: And from here on, the commands are the same as for my Howto: Make Your Own Cert With OpenSSL openssl command: SYNOPSIS . openssl genrsa [-help] [-out filename] [-passout arg For more information about the format of arg see the PASS PHRASE ARGUMENTS section in the openssl reference page. -aes128 |-aes192 |-aes256 |-aria128 |-aria192 |-aria256 |-camellia128 |-camellia192 |-camellia256 |-des |-des3 |-idea . These options encrypt the private key with specified cipher before outputting. openssl - the command for executing OpenSSL; pkcs7 - the file utility for PKCS#7 files in OpenSSL-print_certs -in certificate.p7b - prints out any certificates or CRLs contained in the file.-out certificate.crt - output the file as certificate.crt; Note: You can also use OpenSSL to extract the certificates and private key from a PKCS#12/PFX file. Video. Thank you for choosing SSL.com. Step 2: Compile OpenSSL from Sources. 2. Next, download the latest stable version of OpenSSL ( v1.0.2 at the time of writing, which is a Long Term Support ( LTS) release, supported until 31st December 2019 ), from the download page using following wget command and unpack it using tar command. 3 openssl x509 -text -in yourdomain.crt -noout. This concludes our list of common OpenSSL commands. If you're looking for more information on what is OpenSSL and how it works, this free book is an excellent resource
COMMAND SUMMARY. The openssl program provides a rich variety of commands (command in the SYNOPSIS) each of which often has a wealth of options and arguments (command_opts and command_args in the SYNOPSIS).. Detailed documentation and use cases for most standard subcommands are available (e.g., x509 or openssl_x509. Many commands use an external configuration file for some or all of their. OpenSSL: Command line examples. October 5, 2014 Michael Albert 1 Comment. Hi, here are some command line examples for openssl: Generate a self signed certificate for a (apache) webserver with a 2048 Bit RSA encryption and valid for 365 days. openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout server.key -out server.crt. Get the certificate of a webserver . openssl s_client -connect. To make sure that you have installed the SSL certificate correctly, we have have compiled a cheatsheet with OpenSSL commands to verify that multiple protocols use the correct certificate. Test FTP certificate. openssl s_client -connect server.yourwebhoster.eu:21 -starttls ftp. Test POP3 certificate. openssl s_client -connect server. OpenSSL from the command line. In the meantime, let's take a look at OpenSSL command-line utilities: in particular, a utility to inspect the certificates from a web server during the TLS handshake. Invoking the OpenSSL utilities begins with the openssl command and then adds a combination of arguments and flags to specify the desired operation OpenSSL is a CLI (Command Line Tool) which can be used to secure the server to generate public key infrastructure (PKI) and HTTPS. This article helps you as a quick reference to understand OpenSSL commands which are very useful in common, and for everyday scenarios especially for system administrators
OpenSSL command line Root and Intermediate CA including OCSP, CRL and revocation Table of Contents. These are quick and dirty notes on generating a certificate authority (CA), intermediate certificate... Root CA. If you want to password-protect this key, add the option -aes256. You are about to be. With reference to the Archive attachments from Mail.app messages hint, we can use OpenSSL to convert a specific Mail attachment from Base64 and back using the following command(s):. To decode from Base64: openssl base64 -d -in <infile> -out <outfile> Conversely, to encode to Base64: openssl base64 -in <infile> -out <outfile> Where infile refers to the input filename (source) and outfile refers. For Total Commander 64-bit, get openssl-VERSION-x64_86-win64.zip For the combined version, download both. Unzip the 32-bit dlls to the Total Commander or plugin directory. The 64-bit dlls go to the subdirectory named 64 (without the quotes). To find the right location, please put the following command in the Total Commander command line (above buttons F5, F6) and press ENTER: cd %commander.
imap, mail, commandline, openssl, ssl, telnet, kommandozeile, cli, ip. 1) wofür ist denn immer das 'A'? (z.B. bei A imapuser meingeheimespasswort) , fragt Julian Winter. Dafür musste ich auch in RFC 3501 nachsehen: Each client command is prefixed with an identifier (typically a short alphanumeric string, e.g., A0001, A0002, etc.) called a tag. A different tag is generated by the. OpenSSL - commandes utiles. Dernière mise à jour: 14/06/2018. Comment se servir d'OpenSSL? OpenSSL est véritablement le couteau suisse de la gestion de certificats, mais à l'instar du canif suisse, on passe un temps fou à essayer de distinguer la lime à ongles du tire-bouchon. Vous trouverez ci-dessous une liste des commandes les plus fréquemment utilisées. Demandes de certificats et.
OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) network protocols and related cryptography standards required by them.. It also includes the openssl command, which provides a rich variety of commands You can use the same command to debug problems with SSL certificates For starters, you're going to use the openssl to test connections. For example, if you have a web server you might traditionally attempt to telnet into port 80 and check you banners; however, if you have an SSL certificate on it then you might be better served connecting to port 443 using the openssl command. In the following example we'll tell openssl to be a generic client (s_client) and. OpenSSL has different modes, officially called 'commands' specified as the first argument. After you specify a particular 'command', all the remaining arguments are specific to that command. Eg: the enc command is great for encrypting files. the s_client command is an SSL client you can use for testing handshakes against your server The first OpenSSL command generates a 2048-bit (recommended) RSA private key. The second command generates a Certificate Signing Request, which you could instead use to generate a CA-signed certificate. This step will ask you questions; be as accurate as you like since you probably aren't getting this signed by a CA. The third command generates a self-signed x509 certificate suitable for use.
Before installing the custom OpenSSL version to the system, let's check the installed version using the command below. openssl version -a. Below is my results on Ubuntu: And this is on CentOS: We will replace the '1.1.0g' version with the latest stable version 1.0.2o. We will install the new OpenSSL version to the specific directory '/usr/local/ssl', and then enable the Link Libraries of. OpenSSL command line HMAC. Hi, To generate an HMAC key using SHA-256, I can issue the following command: openssl dgst -sha256 -hmac <key> -binary < message.bin > mac.bin I realised..
OpenSSL Command Tool. Simplify the task of creating a Certificate Signing Request with our OpenSSL CSR Command Tool. Complete the form, then paste the resulting command into your terminal. You may also generate the CSR using OpenSSL's step-by-step process: openssl req -new -newkey rsa:2048 -keyout mykey.key -nodes -out mycsr.csr. Common Name: DN Email: Organisation: Organisation Units. The following OpenSSL command will take an encrypted private key and decrypt it. openssl rsa \ -in encrypted.key \ -out decrypted.key. When prompted, enter the passphrase to decrypt the private key. Conclusion. After this tutorial guide should know how to generate a certificate signing request using OpenSSL, as well as troubleshoot most common errors. Make sure to verify each certificate. Generating HMAC Signatures on the Command Line with OpenSSL. Proving authenticity of a message is important, even over transport methods such as HTTPS, as we may not be able to require full end-to-end encryption. One such method of producing a signature is using HMAC with a shared secret. For instance, let us say that we want to use SHA256 as. OpenSSL requires engine settings in the openssl.cnf file. Some OpenSSL commands allow specifying -conf ossl.conf and some do not. Setting the environment variable OPENSSL_CONF always works, but be aware that sometimes the default openssl.cnf contains entries that are needed by commands like openssl req. In other words, you may have to add the engine entries to your default OpenSSL config file.
C:\cygwin\bin\openssl.exe or can be like this C:\Users\openssl\bin\openssl.exe; If command successfully work then you will see this command : Enter keystore password : typeyourpassword. Encryptedhashkey** Questions: Answers: it's late answer but it will help to lazy people like me.. add this code to your Application class, there is no need to download openssl and no need to set the. OpenSSL Version Command. The openssl version command allows you to determine the version your system is currently using. This information is useful if you want to find out if a particular feature is available, verify whether a security threat affects your system, or perhaps report a bug. Type in: openssl version. The resulting data will consist of the OpenSSL version designation and the date. Then click Win64 OpenSSL Command Prompt App from the search results above. This will open the following command prompt and you can see that OpenSSL 1.1.1g version is successfully installed in your Windows 10 machine as shown below. That's it :-). Now you are ready to create public keys and private keys using OpenSSL library. For example, to generate public and private key pairs you.
This command takes an IP address or domain name as argument: EHLO stevenrombauts.be. On most SMTP servers you will get a list of commands back when using the Extended Hello (EHLO) command: 250-smtp.sendgrid.net 250-8BITMIME 250-PIPELINING 250-SIZE 31457280 250-AUTH PLAIN LOGIN 250 AUTH=PLAIN LOGIN. Authenticate yourself. Time to log in! The previous output listed the AUTH command and the. DESCRIPTION. OpenSSL is a cryptography toolkit implementing the Transport Layer Security (TLS v1) network protocol, as well as related cryptography standards.. The openssl program is a command line tool for using the various cryptography functions of openssl's crypto library from the shell.. The pseudo-commands list-standard-commands, list-message-digest-commands, and list-cipher-commands. OpenSSL is a widely used and a well known open source tool for generating self signed certificates, private keys, CSRs (Certificate Signing Requests) and for converting certificates from one format to another. Other than OpenSSL, Java Key Took is also a commonly used command line tool for certificates, keys and CSRs generation and I have another video tutorial, explaining how to use Java.