Checking for LibreSSL with autotools

autotools

### Pass LDFLAGS and CPPFLAGS to configure using CONFIGURE_ENV

    .if ${WITH_OPENSSL_PORT}
    CONFIGURE_ENV+=	CPPFLAGS=-I/usr/local/include LDFLAGS=-L/usr/local/lib
    .endif

### In configure.ac

    AC_CHECK_LIB(crypto, RAND_egd, AC_DEFINE(HAVE_RAND_EGD, 1, [Define if the libcrypto has RAND_egd]))

### In c

    #ifdef HAVE_OPENSSL_RAND
    bla
    #endif