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

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?

Update: The answer is sudo 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?

Answer 1

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

Answer 2

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

sudo apt-get install libssl-dev

Answer 3

apt-get install libssl-dev

Answer 4

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 "synergy" app (sudo synergy) 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".