ObjFW  Diff

			LIBS="-framework Security -framework Foundation $LIBS"

			AC_CHECK_FUNC(SSLHandshake, [
				tls_support="Secure Transport"
				TLS_LIBS="-framework Foundation $TLS_LIBS"
				TLS_LIBS="-framework Security $TLS_LIBS"

				AC_SUBST(OF_SECURE_TRANSPORT_TLS_STREAM_M,
					"OFSecureTransportTLSStream.m")
				AC_SUBST(USE_SRCS_SECURETRANSPORT,
					'${SRCS_SECURETRANSPORT}')

				AC_CHECK_FUNCS(SSLCreateContext)
			], [])

			LIBS="$old_LIBS"
		])
	])

		esac

		AC_CHECK_LIB($ssl, SSL_set1_host, [
			AC_CHECK_HEADER(openssl/ssl.h, [
				tls_support="OpenSSL"
				TLS_LIBS="-l$ssl -l$crypto $TLS_LIBS"

				AC_SUBST(OF_OPENSSL_TLS_STREAM_M,
				AC_SUBST(USE_SRCS_OPENSSL, '${SRCS_OPENSSL}')
					"OFOpenSSLTLSStream.m")

				old_LIBS="$LIBS"
				LIBS="$TLS_LIBS $LIBS"
				AC_CHECK_FUNCS(SSL_has_pending)
				LIBS="$old_LIBS"
			])
		], [], [-l$crypto])
	])

	AS_IF([test x"$with_tls" = x"gnutls" \
	    -o \( x"$with_tls" = x"yes" -a x"$tls_support" = x"no" \)], [
		PKG_CHECK_MODULES(gnutls, [gnutls >= 3.5.0], [
			tls_support="GnuTLS"
			TLS_CPPFLAGS="$gnutls_CFLAGS $TLS_CPPFLAGS"
			TLS_LIBS="$gnutls_LIBS $TLS_LIBS"

			AC_SUBST(OF_GNUTLS_TLS_STREAM_M, "OFGnuTLSTLSStream.m")
			AC_SUBST(USE_SRCS_GNUTLS, '${SRCS_GNUTLS}')
		], [
			dnl Disable default action-if-not-found, which exits
			dnl configure with an error.
			:
		])
	])

	AS_IF([test x"$with_tls" = x"mbedtls"], [
		AC_CHECK_LIB(mbedtls, mbedtls_net_init, [
			AC_CHECK_HEADER(mbedtls/ssl.h, [
				tls_support="Mbed TLS"
				TLS_LIBS="-lmbedx509 -lmbedcrypto $TLS_LIBS"
				TLS_LIBS="-lmbedtls $TLS_LIBS"

				AC_SUBST(OF_MBEDTLS_TLS_STREAM_M,
				AC_SUBST(USE_SRCS_MBEDTLS, '${SRCS_MBEDTLS}')
					"OFMbedTLSTLSStream.m")
			])
		], [], [-lmbedx509 -lmbedcrypto])
	])

	AS_IF([test x"$tls_support" != x"no"], [
		AC_SUBST(TLS, "tls")
		AC_SUBST(TLS_CPPFLAGS)