How do I install the OpenSSL libraries on Ubuntu? – Dev

The best answers to the question “How do I install the OpenSSL libraries on Ubuntu?” in the category Dev.

QUESTION:

I’m trying to build some code on Ubuntu 10.04 LTS that uses OpenSSL 1.0.0. When I run make, it invokes g++ with the “-lssl” option. The source includes:

#include <openssl/bio.h>
#include <openssl/buffer.h>
#include <openssl/des.h>
#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/rsa.h>

I ran:

$ sudo apt-get install openssl
Reading package lists... Done
Building dependency tree       
Reading state information... Done
openssl is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.

But I guess the openssl package doesn’t include the library. I get these errors on make:

foo.cpp:21:25: error: openssl/bio.h: No such file or directory
foo.cpp:22:28: error: openssl/buffer.h: No such file or directory
foo.cpp:23:25: error: openssl/des.h: No such file or directory
foo.cpp:24:25: error: openssl/evp.h: No such file or directory
foo.cpp:25:25: error: openssl/pem.h: No such file or directory
foo.cpp:26:25: error: openssl/rsa.h: No such file or directory

How do I install the OpenSSL C++ library on Ubuntu 10.04 LTS?

I did a man g++ and (under “Options for Linking”) for the -l option it states: ” The linker searches a standard list of directories for the library…” and “The directories searched include several standard system directories…” What are those standard system directories?

ANSWER:

Run:

apt-get install libssl-dev

ANSWER:

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

sudo apt-get install libssl-dev

ANSWER:

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

ANSWER:

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.