How to install OpenSSL in windows 10?

Question

I also wanted to create OPEN SSL for Windows 10. An easy way of getting it done without running into a risk of installing unknown software from 3rd party websites and risking entries of viruses, is by using the openssl.exe that comes inside your Git for Windows installation. In my case, I found the open SSL in the following location of Git for Windows Installation.

C:\Program Files\Git\usr\bin\openssl.exe

If you also want instructions on how to use OPENSSL to generate and use Certificates. Here is a write-up on my blog. The step by step instructions first explains how to use Microsoft Windows Default Tool and also OPEN SSL and explains the difference between them.

http://kaushikghosh12.blogspot.com/2016/08/self-signed-certificates-with-microsoft.html

If you have chocolatey installed you can install openssl via a single command i.e.

choco install openssl

In case you have Git installed,

you can open the Git Bash (shift pressed + right click in the folder -> Git Bash Here) and use openssl command right in the Bash

Do you have Git installed? You can access openssl command from git bash without adding any environment variable.

But, if you want to access the openssl command from windows cmd, then follow me:

1. Find the path of the bin directory of Git. Normally it is at

C:\Program Files\Git\usr\bin\

2. then add the path your environment variable (User variables->Path):

3. 

4. Now open a new command prompt (don't use an already opened cmd, because the already opened cmd doesn't know the new environment variable).

now write:

openssl

Either set the openssl present in Git as your default openssl and include that into your path in environmental variables (quick way)

OR

1. Install the system-specific openssl from this link.
2. set the following variable : set OPENSSL_CONF=LOCATION_OF_SSL_INSTALL\bin\openssl.cfg
3. Update the path : set Path=...Other Values here...;LOCATION_OF_SSL_INSTALL\bin

Necroposting, but might be useful for others:

• There's always the official page: [OpenSSL.Wiki]: Binaries which contains useful URLs

• There are other repositories which contain unofficial builds

  • Here I want to mention: [GitHub]: CristiFati/Prebuilt-Binaries - Prebuilt-Binaries/OpenSSL

    • v1.0.2u is built with OpenSSL-FIPS 2.0.16

    • Artefacts are .zips that should be unpacked in "C:\Program Files" (please take a look at the Readme.md file, and also at the one at the repository root)

• Other 3^rd-party software may bundle OpenSSL, so it gets "installed" as a side effect. Such software (mentioned by other answers): Cygwin, Git

• And of course you can build it yourself from sources, but that requires some deeper knowledge

I recently needed to document how to get a version of it installed, so I've copied my steps here, as the other answers were using different sources from what I recommend, which is Cygwin. I like Cygwin because it is well maintained and provides a wealth of other utilities for Windows. Cygwin also allows you to easily update the versions as needed when vulnerabilities are fixed. Please update your version of OpenSSL often!

Open a Windows Command prompt and check to see if you have OpenSSL installed by entering: openssl version

If you get an error message that the command is NOT recognized, then install OpenSSL by referring to Cygwin following the summary steps below:

Basically, download and run the Cygwin Windows Setup App to install and to update as needed the OpenSSL application:

1. Select an install directory, such as C:\cygwin64. Choose a download mirror such as: http://mirror.cs.vt.edu
2. Enter in openssl into the search and select it. You can also select/un-select other items of interest at this time. The click Next twice then click Finish.
3. After installing, you need to edit the PATH variable. On Windows, you can access the System Control Center by pressing Windows Key + Pause. In the System window, click Advanced System Settings → Advanced (tab) → Environment Variables. For Windows 10, a quick access is to enter "Edit the system environment variables" in the Start Search of Windows and click the button "Environment Variables". Change the PATH variable (double-click on it or Select and Edit), and add the path where your Cywgwin is, e.g. C:\cygwin\bin.
4. Verify you have it installed via a new Command Prompt window: openssl version. For example: C:\Program Files\mosquitto>openssl versionOpenSSL 1.1.1f 31 Mar 2020
   • If not, refer to the Cygwin documentation and also other tutorials such as: https://www.eclipse.org/4diac/documentation/html/installation/cygwin.html