How do I install the OpenSSL libraries on Ubuntu?

You want to install the development package, which is libssl-dev:

sudo apt-get install libssl-dev

Run:

apt-get install libssl-dev

How could I have figured that out for myself (other than asking this question here)? Can I somehow tell apt-get to list all packages, and grep for ssl? Or do I need to know the "lib*-dev" naming convention?

If you're linking with -lfoo then the library is likely libfoo.so. The library itself is probably part of the libfoo package, and the headers are in the libfoo-dev package as you've discovered.

Some people use the GUI "synaptic" app (sudo synaptic) to (locate and) install packages, but I prefer to use the command line. One thing that makes it easier to find the right package from the command line is the fact that apt-get supports bash completion.

Try typing sudo apt-get install libssl and then hit tab to see a list of matching package names (which can help when you need to select the correct version of a package that has multiple versions or other variations available).

Bash completion is actually very useful... for example, you can also get a list of commands that apt-get supports by typing sudo apt-get and then hitting tab.

I found a detailed solution here: Install OpenSSL Manually On Linux

From the blog post...:

Steps to download, compile, and install are as follows (I'm installing version 1.0.1g below; please replace "1.0.1g" with your version number): Step – 1 : Downloading OpenSSL: Run the command as below : $ wget http://www.openssl.org/source/openssl-1.0.1g.tar.gz Also, download the MD5 hash to verify the integrity of the downloaded file for just varifacation purpose. In the same folder where you have downloaded the OpenSSL file from the website : $ wget http://www.openssl.org/source/openssl-1.0.1g.tar.gz.md5 $ md5sum openssl-1.0.1g.tar.gz $ cat openssl-1.0.1g.tar.gz.md5 Step – 2 : Extract files from the downloaded package: $ tar -xvzf openssl-1.0.1g.tar.gz Now, enter the directory where the package is extracted like here is openssl-1.0.1g $ cd openssl-1.0.1g Step – 3 : Configuration OpenSSL Run below command with optional condition to set prefix and directory where you want to copy files and folder. $ ./config --prefix=/usr/local/openssl --openssldir=/usr/local/openssl You can replace “/usr/local/openssl” with the directory path where you want to copy the files and folders. But make sure while doing this steps check for any error message on terminal. Step – 4 : Compiling OpenSSL To compile openssl you will need to run 2 command : make, make install as below : $ make Note: check for any error message for verification purpose. Step -5 : Installing OpenSSL: $ sudo make install Or without sudo, $ make install That’s it. OpenSSL has been successfully installed. You can run the version command to see if it worked or not as below : $ /usr/local/openssl/bin/openssl version OpenSSL 1.0.1g 7 Apr 2014

Another way to install openssl library from source code on Ubuntu, follows steps below, here WORKDIR is your working directory:

sudo apt-get install pkg-config
cd WORKDIR
git clone https://github.com/openssl/openssl.git
cd openssl
./config
make
sudo make install
# Open file /etc/ld.so.conf, add a new line: "/usr/local/lib" at EOF
sudo ldconfig

All of these answers are very outdated and from when the package was still being developed. You can now just use the "normal" command listed below:

sudo apt install openssl

You want the openssl-devel package. At least I think it's -devel on Ubuntu. Might be -dev. It's one of the two.

As a general rule, when on Debian or Ubuntu and you're missing a development file (or any other file for that matter), use apt-file to figure out which package provides that file:

~ apt-file search openssl/bio.h
android-libboringssl-dev: /usr/include/android/openssl/bio.h
libssl-dev: /usr/include/openssl/bio.h
libwolfssl-dev: /usr/include/cyassl/openssl/bio.h
libwolfssl-dev: /usr/include/wolfssl/openssl/bio.h

A quick glance at each of the packages that are returned by the command, using apt show will tell you which among the packages is the one you're looking for:

~ apt show libssl-dev
Package: libssl-dev
Version: 1.1.1d-2
Priority: optional
Section: libdevel
Source: openssl
Maintainer: Debian OpenSSL Team <pkg-openssl-devel@lists.alioth.debian.org>
Installed-Size: 8,095 kB
Depends: libssl1.1 (= 1.1.1d-2)
Suggests: libssl-doc
Conflicts: libssl1.0-dev
Homepage: https://www.openssl.org/
Tag: devel::lang:c, devel::library, implemented-in::TODO, implemented-in::c,
 protocol::ssl, role::devel-lib, security::cryptography
Download-Size: 1,797 kB
APT-Sources: http://ftp.fr.debian.org/debian unstable/main amd64 Packages
Description: Secure Sockets Layer toolkit - development files
 This package is part of the OpenSSL project's implementation of the SSL
 and TLS cryptographic protocols for secure communication over the
 Internet.
 .
 It contains development libraries, header files, and manpages for libssl
 and libcrypto.

N: There is 1 additional record. Please use the '-a' switch to see it

Go to the official website and download the source code for the version you need Then unzip the update package and execute the following command ./config --prefix=/usr/local/ssl --openssldir=/usr/local/ssl -Wl,-rpath,/usr/local/ssl/lib shared

Because the default is to generate only static libraries, if you want dynamic libraries, add the "shared" option

make && make install

sudo apt-get install libcurl4-openssl-dev