If you download openssl for windows, you can find header files, dll files, and library files used in C++ compiler.

However, you can not use library files(libeay32.lib, ssleay32.lib) with C++Builder without any converting.

1. Use "coff2omf" command.

coff2omf libeay32.lib libeay32_cb2007.lib

coff2omf ssleay32.lib ssleay32_cb2007.lib

But strange to say, library files(*_cb2007.lib) do not work fine with C++Builder.

You should do as follows.

2. Use "implib" command.

implib -a libeay32_cb2007.lib libeay32.dll

implib -a ssleay32_cb2007.lib ssleay32.dll

Now, you can use library files with CodeGear C++Builder 2007.

Download library files for C++Builder 2007 : openssl_lib_2007.zip