+dnl -----------------
+dnl Enable TLS?
+dnl -----------------
+dnl By default (with_tls=''), enable TLS if header and libs were found.
+dnl If TLS requested (--with-tls with_tls=yes), error if header/lib not found.
+dnl If TLS disabled (--without-tls with_tls=no), don't enable it.
+tls_support=no
+TLS_SUPPORT=0
+AC_SUBST([TLS_SUPPORT])
+AS_IF([test "x$with_tls" = xyes && test "x$HAVE_SSL_H" = x],
+ [AC_MSG_ERROR([TLS requested but openssl/ssl.h not found])],
+ [test "x$with_tls" = xyes && test "x$TLSLIB" = x],
+ [AC_MSG_ERROR([TLS requested but crypto or ssl library not found])],
+ [test "x$with_tls" != xno && test "x$HAVE_SSL_H" = x1 && test "x$TLSLIB" != x],
+ [AC_DEFINE([TLS_SUPPORT], [1], [Support TLS for session encryption.])
+ TLS_SUPPORT=1
+ tls_support=yes
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $TLSLIB"
+ AC_CHECK_FUNCS([X509_VERIFY_PARAM_set1_host])
+ LIBS="$save_LIBS"])
+
+dnl -----------------
+dnl CHECK FOR CURL
+dnl -----------------
+dnl Look for curl if oauth not disabled (--without-oauth).
+AC_PATH_PROG([curl_config], [curl-config])
+AS_IF([test "x$with_oauth" != xno && test -n "$curl_config"], [
+ save_CFLAGS="$CFLAGS"
+ CFLAGS="$AM_CPPFLAGS $AM_CFLAGS $CFLAGS `$curl_config --cflags`"
+ AC_CHECK_HEADER([curl/curl.h], [
+ HAVE_CURL_H=1
+ AC_CHECK_LIB([curl], [curl_easy_init], [
+ CURLLIB="`$curl_config --libs`"
+ AC_SUBST([CURLLIB])
+ CURL_USER_AGENT="`$curl_config --version | sed 's|^libcurl *|libcurl/|; q'`"
+ AS_IF([test "x$CURL_USER_AGENT" != "x`echo $CURL_USER_AGENT | sed 's/ //'`"],
+ [AC_MSG_WARN([unexpected curl-config --version: $CURL_USER_AGENT])
+ CURL_USER_AGENT=libcurl/UNKNOWN])
+ AC_SUBST([CURL_USER_AGENT])
+ ])
+ ])
+ CFLAGS="$save_CFLAGS"
+ ])
+
+dnl -----------------
+dnl Enable OAuth?
+dnl -----------------
+dnl By default (with_oauth=''), enable OAuth if curl is found.
+dnl If OAuth requested (--with-oauth with_oauth=yes), error if curl not found.
+dnl If OAuth disabled (--without-oauth with_oauth=no), don't enable it.
+oauth_support=no
+OAUTH_SUPPORT=0
+AC_SUBST([OAUTH_SUPPORT])
+AS_IF([test "x$with_oauth" = xyes && test "x$HAVE_CURL_H" = x],
+ [AC_MSG_ERROR([OAuth requested but curl/curl.h not found])],
+ [test "x$with_oauth" = xyes && test "x$CURLLIB" = x],
+ [AC_MSG_ERROR([OAuth requested but curl library not found])],
+ [test "x$with_oauth" != xno && test "x$HAVE_CURL_H" = x1 && test "x$CURLLIB" != x],
+ [AC_DEFINE([OAUTH_SUPPORT], [1], [Support OAuth2 in SMTP auth.])
+ OAUTH_SUPPORT=1
+ oauth_support=yes])
+