# How to Build C++ Cryptographic Library, Crypto++

Crypto++ is an awesome free and open source C++ class library of cryptographic algorithms and schemes which fully supports 32-bit and 64-bit architectures for many major operating systems, including FreeBSD, Linux, Solaris, Windows, Mac OS X and iOS. Currently, Crypto++ officially supports the following compilers:

• MSVC 6.0 - 2010
• GCC 3.3 - 4.5
• C++Builder 2010
• Intel C++ Compiler 9 - 11.1
• Sun Studio 12u1, Express 1108, Express 06/10

In spite of the power that Crypto++ offers, building and using it can be a little bit tricky. In the following we will describe the process of building Crypto++ on both FreeBSD and Windows using the GCC, MinGW and VC++ compilers.

### How do I build Crypto++ on FreeBSD?

Before we start building Crypto++ on FreeBSD, I have to warn about a bug which has been discovered and reported by me that affects FreeBSD PCs with AVX enabled CPUs.

For the first time, the AVX FPU extension kernel support appeared in FreeBSD 9.1-STABLE. And, while still there’s no release version of GCC out with the patch which disables the AVX if it isn’t supported; So you should follow the instructions carefully if you have older versions of FreeBSD with GCC 4.4+, or simply use a recent snapshot of your favorite GCC version.

1. I prefer to install Crypto++ from FreeBSD ports. So:

$cd /usr/ports/security/cryptopp/$ make config


I usually build Crypto++ with these options:

[ ] DEBUG    Install debug symbols
[ ] DOCS     Build and/or install documentation
[*] GCC46    Build with GCC 4.6+
[*] STATIC   Build static version only (no shared libs)


If the bug affects you (FreeBSD < 9.1+, having older versions or snapshots of GCC 4.4+ enabled as default compiler), first you should uncheck GCC46 option, then disable the newer version of GCC for Crypto++ in your /etc/make.conf beforehand.

/etc/make.conf

.if !empty(.CURDIR:M/usr/ports/*) && exists(/usr/local/bin/gcc46)
.if empty(.CURDIR:M/usr/ports/security/cryptopp*)
CC=gcc46
CXX=g++46
CPP=cpp46
.endif
.endif


2. Build and install Crypto++ by issuing the following command:

$make install clean  Note: If you are affected by the above bug, you should pay attention to the g++ options which are applied by Ports at this step. You should use the same options to build your own code with Crypto++. ### How do I build Crypto++ using MinGW on Microsoft Windows? Also, there is an easier solution which I found on Qt Centre forums that relies on qmake. Therefore, you should have Qt installed to build the library. Please note that the built library using this method does not need Qt libraries in order to function properly. We only need qmake to generate the approperiate makefiles in order to be able to build Crypto++ on MinGW and Windows platform. 1. Open an instance of cmd.exe and navigate to the extracted source directory of Crypto++ (e.g. cryptopp561). 2. Then run the following commands: > erase /f GNUmakefile > qmake -project  3. Now there should be a file named CURRENT_DIRECTORY.pro (e.g. cryptopp561.pro) which is generate by the previous qmake command. Open the generated .pro file in your favorite editor and make the following changes: /etc/make.conf  #TEMPLATE = app #TARGET = cryptopp561 #INCLUDEPATH += . TEMPLATE = lib TARGET = cryptopp INCLUDEPATH += . CONFIG -= qt LIBS += -lws2_32  4. Open fipstest.cpp and replace every ‘OutputDebugString’ with ‘OutputDebugStringA’. 5. Finally, generate the proper makefiles and build the library by using the following commands: > qmake > mingw32-make all -j<NUMBER_OF_YOUR_CPU_CORES + 1>  6. Copy the following .dll (shared) and .a (static) files, generated for both debug and release variants to YOUR_COMPILER_LINK_PATH. CRYPTOPP_SOURCE_DIRECTORY/debug/cryptopp.dll CRYPTOPP_SOURCE_DIRECTORY/debug/libcryptopp.a CRYPTOPP_SOURCE_DIRECTORY/release/cryptopp.dll CRYPTOPP_SOURCE_DIRECTORY/release/libcryptopp.a  7. Copy CRYPTOPP_SOURCE_DIRECTORY/*.h files to YOUR_COMPILER_INCLUDE_PATH/cryptopp/ in order to be able to include Crypto++ headers from your own code. ### How to build Crypto++ dynamically on Microsoft Windows and Visual C++? Here is a comprehensive awesome tutorial on compiling and integrating Crypto++ into the Microsoft Visual C++ environment which covers everything about Crypto++ on Windows and MSVC compiler. Note: Default project file for building the dynamic version which ships with Crypto++ uses static linking (/MT or /MTd). This is so wrong, and it should be /MD or /MDd. Despite the fact that dynamic version builds just fine, you will end up in plenty of ambiguous linker errors when linking your own code against the dynamic version of Crypto++. The reason is that your are linking against different versions of the run-time libraries. So, do not mix static and dynamic versions of the run-time libraries. All modules passed to a given invocation of the linker must have been compiled with the same run-time library compiler option (/MD, /MT, /LD). ### How do I build Crypto++ statically on Microsoft Windows and Visual C++? 1. Grab a copy of the latest source release of Crypto++ and extract it somewhere. 2. Open up cryptest.sln in VC++ IDE 3. There are 4 projects in the solution, and the only one that we need to build static version of Crypto++ is the cryptlib project. So, right click on the cryptlib project and ensure that you have the following settings for the project in both Debug and Release build modes: Debug: Configuration Properties > General > Target Name >$(ProjectName)_d
Configuration Properties > General > Configuration Type > Static library (.lib)
Configuration Properties > C/C++ > Code Generation > Runtime Library > Multi-threaded Debug (/MTd)
Configuration Properties > C/C++ > Output Files > Program Database File Name > $(OutDir)$(ProjectName)_d.pdb

Release:
Configuration Properties > General > Target Name > $(ProjectName) Configuration Properties > General > Configuration Type > Static library (.lib) Configuration Properties > C/C++ > Code Generation > Runtime Library > Multi-threaded (/MT) Configuration Properties > C/C++ > Output Files > Program Database File Name >$(OutDir)\$(ProjectName).pdb


4. Now build the cryptlib project in both Debug and Release build modes. If everything goes smoothly, grab these files and copy them to your lib folder:

Debug:
{Crypto++ Source Directory}\Win32\Output\Debug\cryptlib_d.lib
{Crypto++ Source Directory}\Win32\Output\Debug\cryptlib_d.pdb

Release:
{Crypto++ Source Directory}\Win32\Output\Release\cryptlib.lib
{Crypto++ Source Directory}\Win32\Output\Release\cryptlib.pdb


5. Last but not least, copy all the *.h files from the extracted Crypto++ source directory to {your own include directory}/cryptopp.

_Note: When you’re using static builds with VC++ on Windows you should always include Windows.h before Crypto++ headers, or else, you’ll have difficulties._

#if defined(WIN32)
#include <windows.h>
#endif

#include <cryptopp/aes.h>
#include <cryptopp/ccm.h>
#include <cryptopp/cryptlib.h>
#include <cryptopp/filters.h>
#include <cryptopp/hex.h>
#include <cryptopp/sha.h>


### How do I build 64-bit version on Microsoft Windows and Visual C++?

Again, here is a comprehensive awesome tutorial on compiling and integrating Crypto++ into the Microsoft Visual C++ environment which covers everything about Crypto++ on Windows and MSVC compiler.

### How do I build FIPS compliant version of Crypto++?

You can’t! You cannot build the Crypto++ DLL and claim it’s FIPS compliant. The FIPS DLL must be used in binary form as distributed by the author, even though we have the source code and can build the same binary. For more information on FIPS 140-2 Conformance see here and here.

Write your own cross-platform cryptographic library