Code::Blocks openssl/MD5 라이브러리 첨부방법

1. ubuntu openssl 설치

   : sudo apt-get install libssl-dev openssl

     * openssl만 설치하면 header file을 읽을수 없다. 개발을 위해서는 libssl-dev 패키지도 같이 설치한다.

2. Linux Code::Blocks MD5 라이브러리 사용하기 

#include <openssl/md5.h>

Project build options->Linker settings->Link libraries  crypto 추가

Here are the steps I used to make this work, be sure to follow them carefully:

1. Go to Project build options->Compiler settings->#defines: type in CURL_STATICLIB. When this is defined the libcurl.h header will have its function signatures preprocessed to fit static linkage. Otherwise dynamic linkage is assumed and the mangled names then become _imp__*. The unresolved errors from your screenshot indicate it's attempting a dynamic link rather than the desired static link.
   

2. Under Project build options->Linker settings->Link libraries make sure it contains the following: curl, rtmp, idn, ssl, ssh2, crypto, z, ws2_32, wldap32, winmm, gdi32. Note that order is important. Due to a design deficiency of the gnu linker, the most dependant libraries need to be listed first followed by least dependant. Other linkers like msvc link and borland's ilinker do not exhibit such issues -- the libraries can be listed in any order.

3. Under Project build options->Linker settings->Other linker options add in '-static'. This will make sure that the static version of 'idn' is used. If this switch is omitted then your compiled program could depend on 'libidn-11.dll' to run which probably isn't what you want.
   

At this point, you should be able to compile and link libcurl programs without any issues. A couple things worth mentioning,

• Under Other linker options the other extra switches from your screenshot aren't needed. 'libcurl.a' is already listed and covered by Link libraries.

• The 'libcrypto.a' seems to cover the same references as the 'libeay32.a' so only one of them is needed. However, 'libeay32.a' causes dynamic linkage despite its larger size. If you want your application to be 'fully self-contained' use 'libcrypto.a' instead like in the screenshot.

• If you wish to link dynamically in the future, just replace the listing with 'curldll' under Link librariesand remove the CURL_STATICLIB define. The extra libraries (eg. ssl, idn, rtmp etc.) aren't needed since libcurl.dll already covers them.

• You can avoid the tedious error prone setup of a new libcurl program by employing codeblocks' user templates. (eg. File->New->Project->User templates)

Hopefully this resolves any build problems you have with libcurl once and for all.