diff --git a/Makefile.am b/Makefile.am
index 68689c0a..85a37975 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -2,7 +2,7 @@
 
 AUTOMAKE_OPTIONS = gnu
 
-SUBDIRS = test src doc gui
+SUBDIRS =  src doc gui test systemd
 
 ACLOCAL_AMFLAGS = -I m4
 
diff --git a/configure.ac b/configure.ac
index 5b124c61..4893c398 100644
--- a/configure.ac
+++ b/configure.ac
@@ -132,6 +132,17 @@ AC_ARG_WITH(windows2000,
   ]
 )
 
+AC_ARG_WITH(systemd,
+  AS_HELP_STRING([--with-systemd@<:@=DIR@:>@], [install systemd service files @<:@to DIR if specified@:>@]),
+  [ systemd=true; systemd_path="$with_systemd" ],
+  [ systemd=false ]
+)
+
+AS_IF([test "x$with_systemd" = "xyes"], [systemd_path="/lib/systemd/system"],
+      [AS_IF([test "x$with_systemd" = "xno"], [systemd=false])])
+
+AC_SUBST(systemd_path, $systemd_path)
+
 AM_CONDITIONAL(LINUX, test "$linux" = true)
 AM_CONDITIONAL(BSD, test "$bsd" = true)
 AM_CONDITIONAL(OPENBSD, test "$openbsd" = true)
@@ -142,15 +153,12 @@ AM_CONDITIONAL(CYGWIN, test "$cygwin" = true)
 AM_CONDITIONAL(UML, test "$uml" = true)
 AM_CONDITIONAL(VDE, test "$vde" = true)
 AM_CONDITIONAL(TUNEMU, test "$tunemu" = true)
+AM_CONDITIONAL(WITH_SYSTEMD, test "$systemd" = true)
 
 AC_CACHE_SAVE
 
-if test -d /sw/include ; then
-  CPPFLAGS="$CPPFLAGS -I/sw/include"
-fi
-if test -d /sw/lib ; then
-  LIBS="$LIBS -L/sw/lib"
-fi
+AS_IF([test -d /sw/include], [CPPFLAGS="$CPPFLAGS -I/sw/include"])
+AS_IF([test -d /sw/lib], [LIBS="$LIBS -L/sw/lib"])
 
 dnl Compiler hardening flags
 dnl No -fstack-protector-all because it doesn't work on all platforms or architectures.
@@ -270,15 +278,12 @@ tinc_READLINE
 tinc_ZLIB
 tinc_LZO
 
-if test "x$enable_legacy_protocol" != "xno"; then
-	if test -n "$with_libgcrypt"; then
-		gcrypt=true
-		tinc_LIBGCRYPT
-	else
-		openssl=true
-		tinc_OPENSSL
-	fi
-fi
+AS_IF([test "x$enable_legacy_protocol" != "xno"],
+      [AS_IF([test -n "$with_libgcrypt"],
+	     [gcrypt=true; tinc_LIBGCRYPT],
+	     [openssl=true; tinc_OPENSSL])
+      ]
+)
 
 AM_CONDITIONAL(OPENSSL, test -n "$openssl")
 AM_CONDITIONAL(GCRYPT, test -n "$gcrypt")
@@ -291,7 +296,7 @@ AC_ARG_ENABLE(jumbograms,
   ]
 )
 
-AC_CONFIG_FILES([Makefile src/Makefile doc/Makefile gui/Makefile test/Makefile])
+AC_CONFIG_FILES([Makefile src/Makefile doc/Makefile gui/Makefile test/Makefile systemd/Makefile])
 
 AC_CONFIG_TESTDIR(test/, [test-path = 'test/'])
 
diff --git a/src/ed25519/fe.c b/src/ed25519/fe.c
index 448e3e92..1c459f4e 100644
--- a/src/ed25519/fe.c
+++ b/src/ed25519/fe.c
@@ -8,9 +8,9 @@
 static uint64_t load_3(const unsigned char *in) {
     uint64_t result;
 
-    result = (uint64_t) in[0];
-    result |= ((uint64_t) in[1]) << 8;
-    result |= ((uint64_t) in[2]) << 16;
+    result = in[0];
+    result |= shlu64(in[1], 8);
+    result |= shlu64(in[2], 16);
 
     return result;
 }
@@ -18,10 +18,10 @@ static uint64_t load_3(const unsigned char *in) {
 static uint64_t load_4(const unsigned char *in) {
     uint64_t result;
 
-    result = (uint64_t) in[0];
-    result |= ((uint64_t) in[1]) << 8;
-    result |= ((uint64_t) in[2]) << 16;
-    result |= ((uint64_t) in[3]) << 24;
+    result = in[0];
+    result |= shlu64(in[1], 8);
+    result |= shlu64(in[2], 16);
+    result |= shlu64(in[3], 24);
     
     return result;
 }
@@ -316,47 +316,47 @@ void fe_frombytes(fe h, const unsigned char *s) {
     int64_t carry8;
     int64_t carry9;
 
-    carry9 = (h9 + (int64_t) (1 << 24)) >> 25;
+    carry9 = (h9 + (1L << 24)) >> 25;
     h0 += carry9 * 19;
-    h9 -= carry9 << 25;
-    carry1 = (h1 + (int64_t) (1 << 24)) >> 25;
+    h9 -= shl64(carry9, 25);
+    carry1 = (h1 + (1L << 24)) >> 25;
     h2 += carry1;
-    h1 -= carry1 << 25;
-    carry3 = (h3 + (int64_t) (1 << 24)) >> 25;
+    h1 -= shl64(carry1, 25);
+    carry3 = (h3 + (1L << 24)) >> 25;
     h4 += carry3;
-    h3 -= carry3 << 25;
-    carry5 = (h5 + (int64_t) (1 << 24)) >> 25;
+    h3 -= shl64(carry3, 25);
+    carry5 = (h5 + (1L << 24)) >> 25;
     h6 += carry5;
-    h5 -= carry5 << 25;
-    carry7 = (h7 + (int64_t) (1 << 24)) >> 25;
+    h5 -= shl64(carry5, 25);
+    carry7 = (h7 + (1L << 24)) >> 25;
     h8 += carry7;
-    h7 -= carry7 << 25;
-    carry0 = (h0 + (int64_t) (1 << 25)) >> 26;
+    h7 -= shl64(carry7, 25);
+    carry0 = (h0 + (1L << 25)) >> 26;
     h1 += carry0;
-    h0 -= carry0 << 26;
-    carry2 = (h2 + (int64_t) (1 << 25)) >> 26;
+    h0 -= shl64(carry0, 26);
+    carry2 = (h2 + (1L << 25)) >> 26;
     h3 += carry2;
-    h2 -= carry2 << 26;
-    carry4 = (h4 + (int64_t) (1 << 25)) >> 26;
+    h2 -= shl64(carry2, 26);
+    carry4 = (h4 + (1L << 25)) >> 26;
     h5 += carry4;
-    h4 -= carry4 << 26;
-    carry6 = (h6 + (int64_t) (1 << 25)) >> 26;
+    h4 -= shl64(carry4, 26);
+    carry6 = (h6 + (1L << 25)) >> 26;
     h7 += carry6;
-    h6 -= carry6 << 26;
-    carry8 = (h8 + (int64_t) (1 << 25)) >> 26;
+    h6 -= shl64(carry6, 26);
+    carry8 = (h8 + (1L << 25)) >> 26;
     h9 += carry8;
-    h8 -= carry8 << 26;
+    h8 -= shl64(carry8, 26);
 
-    h[0] = (int32_t) h0;
-    h[1] = (int32_t) h1;
-    h[2] = (int32_t) h2;
-    h[3] = (int32_t) h3;
-    h[4] = (int32_t) h4;
-    h[5] = (int32_t) h5;
-    h[6] = (int32_t) h6;
-    h[7] = (int32_t) h7;
-    h[8] = (int32_t) h8;
-    h[9] = (int32_t) h9;
+    h[0] = h0;
+    h[1] = h1;
+    h[2] = h2;
+    h[3] = h3;
+    h[4] = h4;
+    h[5] = h5;
+    h[6] = h6;
+    h[7] = h7;
+    h[8] = h8;
+    h[9] = h9;
 }
 
 
@@ -709,48 +709,48 @@ void fe_mul(fe h, const fe f, const fe g) {
     int64_t carry8;
     int64_t carry9;
 
-    carry0 = (h0 + (int64_t) (1 << 25)) >> 26;
+    carry0 = (h0 + (1L << 25)) >> 26;
     h1 += carry0;
-    h0 -= carry0 << 26;
-    carry4 = (h4 + (int64_t) (1 << 25)) >> 26;
+    h0 -= shl64(carry0, 26);
+    carry4 = (h4 + (1L << 25)) >> 26;
     h5 += carry4;
-    h4 -= carry4 << 26;
+    h4 -= shl64(carry4, 26);
 
-    carry1 = (h1 + (int64_t) (1 << 24)) >> 25;
+    carry1 = (h1 + (1L << 24)) >> 25;
     h2 += carry1;
-    h1 -= carry1 << 25;
-    carry5 = (h5 + (int64_t) (1 << 24)) >> 25;
+    h1 -= shl64(carry1, 25);
+    carry5 = (h5 + (1L << 24)) >> 25;
     h6 += carry5;
-    h5 -= carry5 << 25;
+    h5 -= shl64(carry5, 25);
 
-    carry2 = (h2 + (int64_t) (1 << 25)) >> 26;
+    carry2 = (h2 + (1L << 25)) >> 26;
     h3 += carry2;
-    h2 -= carry2 << 26;
-    carry6 = (h6 + (int64_t) (1 << 25)) >> 26;
+    h2 -= shl64(carry2, 26);
+    carry6 = (h6 + (1L << 25)) >> 26;
     h7 += carry6;
-    h6 -= carry6 << 26;
+    h6 -= shl64(carry6, 26);
 
-    carry3 = (h3 + (int64_t) (1 << 24)) >> 25;
+    carry3 = (h3 + (1L << 24)) >> 25;
     h4 += carry3;
-    h3 -= carry3 << 25;
-    carry7 = (h7 + (int64_t) (1 << 24)) >> 25;
+    h3 -= shl64(carry3, 25);
+    carry7 = (h7 + (1L << 24)) >> 25;
     h8 += carry7;
-    h7 -= carry7 << 25;
+    h7 -= shl64(carry7, 25);
 
-    carry4 = (h4 + (int64_t) (1 << 25)) >> 26;
+    carry4 = (h4 + (1L << 25)) >> 26;
     h5 += carry4;
-    h4 -= carry4 << 26;
-    carry8 = (h8 + (int64_t) (1 << 25)) >> 26;
+    h4 -= shl64(carry4, 26);
+    carry8 = (h8 + (1L << 25)) >> 26;
     h9 += carry8;
-    h8 -= carry8 << 26;
+    h8 -= shl64(carry8, 26);
 
-    carry9 = (h9 + (int64_t) (1 << 24)) >> 25;
+    carry9 = (h9 + (1L << 24)) >> 25;
     h0 += carry9 * 19;
-    h9 -= carry9 << 25;
+    h9 -= shl64(carry9, 25);
 
-    carry0 = (h0 + (int64_t) (1 << 25)) >> 26;
+    carry0 = (h0 + (1L << 25)) >> 26;
     h1 += carry0;
-    h0 -= carry0 << 26;
+    h0 -= shl64(carry0, 26);
 
     h[0] = (int32_t) h0;
     h[1] = (int32_t) h1;
@@ -808,17 +808,17 @@ void fe_mul121666(fe h, fe f) {
     int64_t carry8;
     int64_t carry9;
 
-    carry9 = (h9 + (int64_t) (1<<24)) >> 25; h0 += carry9 * 19; h9 -= carry9 << 25;
-    carry1 = (h1 + (int64_t) (1<<24)) >> 25; h2 += carry1; h1 -= carry1 << 25;
-    carry3 = (h3 + (int64_t) (1<<24)) >> 25; h4 += carry3; h3 -= carry3 << 25;
-    carry5 = (h5 + (int64_t) (1<<24)) >> 25; h6 += carry5; h5 -= carry5 << 25;
-    carry7 = (h7 + (int64_t) (1<<24)) >> 25; h8 += carry7; h7 -= carry7 << 25;
+    carry9 = (h9 + (int64_t) (1<<24)) >> 25; h0 += carry9 * 19; h9 -= shl64(carry9, 25);
+    carry1 = (h1 + (int64_t) (1<<24)) >> 25; h2 += carry1; h1 -= shl64(carry1, 25);
+    carry3 = (h3 + (int64_t) (1<<24)) >> 25; h4 += carry3; h3 -= shl64(carry3, 25);
+    carry5 = (h5 + (int64_t) (1<<24)) >> 25; h6 += carry5; h5 -= shl64(carry5, 25);
+    carry7 = (h7 + (int64_t) (1<<24)) >> 25; h8 += carry7; h7 -= shl64(carry7, 25);
 
-    carry0 = (h0 + (int64_t) (1<<25)) >> 26; h1 += carry0; h0 -= carry0 << 26;
-    carry2 = (h2 + (int64_t) (1<<25)) >> 26; h3 += carry2; h2 -= carry2 << 26;
-    carry4 = (h4 + (int64_t) (1<<25)) >> 26; h5 += carry4; h4 -= carry4 << 26;
-    carry6 = (h6 + (int64_t) (1<<25)) >> 26; h7 += carry6; h6 -= carry6 << 26;
-    carry8 = (h8 + (int64_t) (1<<25)) >> 26; h9 += carry8; h8 -= carry8 << 26;
+    carry0 = (h0 + (int64_t) (1<<25)) >> 26; h1 += carry0; h0 -= shl64(carry0, 26);
+    carry2 = (h2 + (int64_t) (1<<25)) >> 26; h3 += carry2; h2 -= shl64(carry2, 26);
+    carry4 = (h4 + (int64_t) (1<<25)) >> 26; h5 += carry4; h4 -= shl64(carry4, 26);
+    carry6 = (h6 + (int64_t) (1<<25)) >> 26; h7 += carry6; h6 -= shl64(carry6, 26);
+    carry8 = (h8 + (int64_t) (1<<25)) >> 26; h9 += carry8; h8 -= shl64(carry8, 26);
 
     h[0] = h0;
     h[1] = h1;
@@ -1078,42 +1078,42 @@ void fe_sq(fe h, const fe f) {
     int64_t carry7;
     int64_t carry8;
     int64_t carry9;
-    carry0 = (h0 + (int64_t) (1 << 25)) >> 26;
+    carry0 = (h0 + (1L << 25)) >> 26;
     h1 += carry0;
-    h0 -= carry0 << 26;
-    carry4 = (h4 + (int64_t) (1 << 25)) >> 26;
+    h0 -= shl64(carry0, 26);
+    carry4 = (h4 + (1L << 25)) >> 26;
     h5 += carry4;
-    h4 -= carry4 << 26;
-    carry1 = (h1 + (int64_t) (1 << 24)) >> 25;
+    h4 -= shl64(carry4, 26);
+    carry1 = (h1 + (1L << 24)) >> 25;
     h2 += carry1;
-    h1 -= carry1 << 25;
-    carry5 = (h5 + (int64_t) (1 << 24)) >> 25;
+    h1 -= shl64(carry1, 25);
+    carry5 = (h5 + (1L << 24)) >> 25;
     h6 += carry5;
-    h5 -= carry5 << 25;
-    carry2 = (h2 + (int64_t) (1 << 25)) >> 26;
+    h5 -= shl64(carry5, 25);
+    carry2 = (h2 + (1L << 25)) >> 26;
     h3 += carry2;
-    h2 -= carry2 << 26;
-    carry6 = (h6 + (int64_t) (1 << 25)) >> 26;
+    h2 -= shl64(carry2, 26);
+    carry6 = (h6 + (1L << 25)) >> 26;
     h7 += carry6;
-    h6 -= carry6 << 26;
-    carry3 = (h3 + (int64_t) (1 << 24)) >> 25;
+    h6 -= shl64(carry6, 26);
+    carry3 = (h3 + (1L << 24)) >> 25;
     h4 += carry3;
-    h3 -= carry3 << 25;
-    carry7 = (h7 + (int64_t) (1 << 24)) >> 25;
+    h3 -= shl64(carry3, 25);
+    carry7 = (h7 + (1L << 24)) >> 25;
     h8 += carry7;
-    h7 -= carry7 << 25;
-    carry4 = (h4 + (int64_t) (1 << 25)) >> 26;
+    h7 -= shl64(carry7, 25);
+    carry4 = (h4 + (1L << 25)) >> 26;
     h5 += carry4;
-    h4 -= carry4 << 26;
-    carry8 = (h8 + (int64_t) (1 << 25)) >> 26;
+    h4 -= shl64(carry4, 26);
+    carry8 = (h8 + (1L << 25)) >> 26;
     h9 += carry8;
-    h8 -= carry8 << 26;
-    carry9 = (h9 + (int64_t) (1 << 24)) >> 25;
+    h8 -= shl64(carry8, 26);
+    carry9 = (h9 + (1L << 24)) >> 25;
     h0 += carry9 * 19;
-    h9 -= carry9 << 25;
-    carry0 = (h0 + (int64_t) (1 << 25)) >> 26;
+    h9 -= shl64(carry9, 25);
+    carry0 = (h0 + (1L << 25)) >> 26;
     h1 += carry0;
-    h0 -= carry0 << 26;
+    h0 -= shl64(carry0, 26);
     h[0] = (int32_t) h0;
     h[1] = (int32_t) h1;
     h[2] = (int32_t) h2;
@@ -1251,42 +1251,42 @@ void fe_sq2(fe h, const fe f) {
     h7 += h7;
     h8 += h8;
     h9 += h9;
-    carry0 = (h0 + (int64_t) (1 << 25)) >> 26;
+    carry0 = (h0 + (1L << 25)) >> 26;
     h1 += carry0;
-    h0 -= carry0 << 26;
-    carry4 = (h4 + (int64_t) (1 << 25)) >> 26;
+    h0 -= shl64(carry0, 26);
+    carry4 = (h4 + (1L << 25)) >> 26;
     h5 += carry4;
-    h4 -= carry4 << 26;
-    carry1 = (h1 + (int64_t) (1 << 24)) >> 25;
+    h4 -= shl64(carry4, 26);
+    carry1 = (h1 + (1L << 24)) >> 25;
     h2 += carry1;
-    h1 -= carry1 << 25;
-    carry5 = (h5 + (int64_t) (1 << 24)) >> 25;
+    h1 -= shl64(carry1, 25);
+    carry5 = (h5 + (1L << 24)) >> 25;
     h6 += carry5;
-    h5 -= carry5 << 25;
-    carry2 = (h2 + (int64_t) (1 << 25)) >> 26;
+    h5 -= shl64(carry5, 25);
+    carry2 = (h2 + (1L << 25)) >> 26;
     h3 += carry2;
-    h2 -= carry2 << 26;
-    carry6 = (h6 + (int64_t) (1 << 25)) >> 26;
+    h2 -= shl64(carry2, 26);
+    carry6 = (h6 + (1L << 25)) >> 26;
     h7 += carry6;
-    h6 -= carry6 << 26;
-    carry3 = (h3 + (int64_t) (1 << 24)) >> 25;
+    h6 -= shl64(carry6, 26);
+    carry3 = (h3 + (1L << 24)) >> 25;
     h4 += carry3;
-    h3 -= carry3 << 25;
-    carry7 = (h7 + (int64_t) (1 << 24)) >> 25;
+    h3 -= shl64(carry3, 25);
+    carry7 = (h7 + (1L << 24)) >> 25;
     h8 += carry7;
-    h7 -= carry7 << 25;
-    carry4 = (h4 + (int64_t) (1 << 25)) >> 26;
+    h7 -= shl64(carry7, 25);
+    carry4 = (h4 + (1L << 25)) >> 26;
     h5 += carry4;
-    h4 -= carry4 << 26;
-    carry8 = (h8 + (int64_t) (1 << 25)) >> 26;
+    h4 -= shl64(carry4, 26);
+    carry8 = (h8 + (1L << 25)) >> 26;
     h9 += carry8;
-    h8 -= carry8 << 26;
-    carry9 = (h9 + (int64_t) (1 << 24)) >> 25;
+    h8 -= shl64(carry8, 26);
+    carry9 = (h9 + (1L << 24)) >> 25;
     h0 += carry9 * 19;
-    h9 -= carry9 << 25;
-    carry0 = (h0 + (int64_t) (1 << 25)) >> 26;
+    h9 -= shl64(carry9, 25);
+    carry0 = (h0 + (1L << 25)) >> 26;
     h1 += carry0;
-    h0 -= carry0 << 26;
+    h0 -= shl64(carry0, 26);
     h[0] = (int32_t) h0;
     h[1] = (int32_t) h1;
     h[2] = (int32_t) h2;
@@ -1421,33 +1421,33 @@ void fe_tobytes(unsigned char *s, const fe h) {
     /* Goal: Output h-2^255 q, which is between 0 and 2^255-20. */
     carry0 = h0 >> 26;
     h1 += carry0;
-    h0 -= carry0 << 26;
+    h0 -= shl32(carry0, 26);
     carry1 = h1 >> 25;
     h2 += carry1;
-    h1 -= carry1 << 25;
+    h1 -= shl32(carry1, 25);
     carry2 = h2 >> 26;
     h3 += carry2;
-    h2 -= carry2 << 26;
+    h2 -= shl32(carry2, 26);
     carry3 = h3 >> 25;
     h4 += carry3;
-    h3 -= carry3 << 25;
+    h3 -= shl32(carry3, 25);
     carry4 = h4 >> 26;
     h5 += carry4;
-    h4 -= carry4 << 26;
+    h4 -= shl32(carry4, 26);
     carry5 = h5 >> 25;
     h6 += carry5;
-    h5 -= carry5 << 25;
+    h5 -= shl32(carry5, 25);
     carry6 = h6 >> 26;
     h7 += carry6;
-    h6 -= carry6 << 26;
+    h6 -= shl32(carry6, 26);
     carry7 = h7 >> 25;
     h8 += carry7;
-    h7 -= carry7 << 25;
+    h7 -= shl32(carry7, 25);
     carry8 = h8 >> 26;
     h9 += carry8;
-    h8 -= carry8 << 26;
+    h8 -= shl32(carry8, 26);
     carry9 = h9 >> 25;
-    h9 -= carry9 << 25;
+    h9 -= shl32(carry9, 25);
 
     /* h10 = carry9 */
     /*
@@ -1459,32 +1459,32 @@ void fe_tobytes(unsigned char *s, const fe h) {
     s[0] = (unsigned char) (h0 >> 0);
     s[1] = (unsigned char) (h0 >> 8);
     s[2] = (unsigned char) (h0 >> 16);
-    s[3] = (unsigned char) ((h0 >> 24) | (h1 << 2));
+    s[3] = (unsigned char) ((h0 >> 24) | shl32(h1, 2));
     s[4] = (unsigned char) (h1 >> 6);
     s[5] = (unsigned char) (h1 >> 14);
-    s[6] = (unsigned char) ((h1 >> 22) | (h2 << 3));
+    s[6] = (unsigned char) ((h1 >> 22) | shl32(h2, 3));
     s[7] = (unsigned char) (h2 >> 5);
     s[8] = (unsigned char) (h2 >> 13);
-    s[9] = (unsigned char) ((h2 >> 21) | (h3 << 5));
+    s[9] = (unsigned char) ((h2 >> 21) | shl32(h3, 5));
     s[10] = (unsigned char) (h3 >> 3);
     s[11] = (unsigned char) (h3 >> 11);
-    s[12] = (unsigned char) ((h3 >> 19) | (h4 << 6));
+    s[12] = (unsigned char) ((h3 >> 19) | shl32(h4, 6));
     s[13] = (unsigned char) (h4 >> 2);
     s[14] = (unsigned char) (h4 >> 10);
     s[15] = (unsigned char) (h4 >> 18);
     s[16] = (unsigned char) (h5 >> 0);
     s[17] = (unsigned char) (h5 >> 8);
     s[18] = (unsigned char) (h5 >> 16);
-    s[19] = (unsigned char) ((h5 >> 24) | (h6 << 1));
+    s[19] = (unsigned char) ((h5 >> 24) | shl32(h6, 1));
     s[20] = (unsigned char) (h6 >> 7);
     s[21] = (unsigned char) (h6 >> 15);
-    s[22] = (unsigned char) ((h6 >> 23) | (h7 << 3));
+    s[22] = (unsigned char) ((h6 >> 23) | shl32(h7, 3));
     s[23] = (unsigned char) (h7 >> 5);
     s[24] = (unsigned char) (h7 >> 13);
-    s[25] = (unsigned char) ((h7 >> 21) | (h8 << 4));
+    s[25] = (unsigned char) ((h7 >> 21) | shl32(h8, 4));
     s[26] = (unsigned char) (h8 >> 4);
     s[27] = (unsigned char) (h8 >> 12);
-    s[28] = (unsigned char) ((h8 >> 20) | (h9 << 6));
+    s[28] = (unsigned char) ((h8 >> 20) | shl32(h9, 6));
     s[29] = (unsigned char) (h9 >> 2);
     s[30] = (unsigned char) (h9 >> 10);
     s[31] = (unsigned char) (h9 >> 18);
diff --git a/src/ed25519/fixedint.h b/src/ed25519/fixedint.h
index d03e4bdd..8abced09 100644
--- a/src/ed25519/fixedint.h
+++ b/src/ed25519/fixedint.h
@@ -4,6 +4,9 @@
     Not a compatible replacement for <stdint.h>, do not blindly use it as such.
 */
 
+#ifndef __TINC_FIXEDINT_H__
+#define __TINC_FIXEDINT_H__
+
 #if ((defined(__STDC__) && __STDC__ && __STDC_VERSION__ >= 199901L) || (defined(__WATCOMC__) && (defined(_STDINT_H_INCLUDED) || __WATCOMC__ >= 1250)) || (defined(__GNUC__) && (defined(_STDINT_H) || defined(_STDINT_H_) || defined(__UINT_FAST64_TYPE__)) )) && !defined(FIXEDINT_H_INCLUDED)
     #include <stdint.h>
     #define FIXEDINT_H_INCLUDED
@@ -68,3 +71,21 @@
         #define INT64_C(v) v ##I64
     #endif
 #endif
+
+static inline unsigned char shlu8(unsigned char a, uint32_t b) {
+	return a << b;
+}
+
+static inline int32_t shl32(uint32_t a, uint32_t b) {
+	return a << b;
+}
+
+static inline int64_t shl64(uint64_t a, uint32_t b) {
+	return a << b;
+}
+
+static inline uint64_t shlu64(uint64_t a, uint32_t b) {
+	return a << b;
+}
+
+#endif
diff --git a/src/ed25519/ge.c b/src/ed25519/ge.c
index 3c342b1d..94882182 100644
--- a/src/ed25519/ge.c
+++ b/src/ed25519/ge.c
@@ -356,7 +356,7 @@ static void cmov(ge_precomp *t, ge_precomp *u, unsigned char b) {
 static void select(ge_precomp *t, int pos, signed char b) {
     ge_precomp minust;
     unsigned char bnegative = negative(b);
-    unsigned char babs = b - (((-bnegative) & b) << 1);
+    unsigned char babs = b - shlu8(((-bnegative) & b), 1);
     fe_1(t->yplusx);
     fe_1(t->yminusx);
     fe_0(t->xy2d);
@@ -404,7 +404,7 @@ void ge_scalarmult_base(ge_p3 *h, const unsigned char *a) {
         e[i] += carry;
         carry = e[i] + 8;
         carry >>= 4;
-        e[i] -= carry << 4;
+        e[i] -= shl32(carry, 4);
     }
 
     e[63] += carry;
diff --git a/src/ed25519/sc.c b/src/ed25519/sc.c
index ca5bad2c..42cfc2da 100644
--- a/src/ed25519/sc.c
+++ b/src/ed25519/sc.c
@@ -4,9 +4,9 @@
 static uint64_t load_3(const unsigned char *in) {
     uint64_t result;
 
-    result = (uint64_t) in[0];
-    result |= ((uint64_t) in[1]) << 8;
-    result |= ((uint64_t) in[2]) << 16;
+    result = in[0];
+    result |= shlu64(in[1], 8);
+    result |= shlu64(in[2], 16);
 
     return result;
 }
@@ -14,10 +14,10 @@ static uint64_t load_3(const unsigned char *in) {
 static uint64_t load_4(const unsigned char *in) {
     uint64_t result;
 
-    result = (uint64_t) in[0];
-    result |= ((uint64_t) in[1]) << 8;
-    result |= ((uint64_t) in[2]) << 16;
-    result |= ((uint64_t) in[3]) << 24;
+    result = in[0];
+    result |= shlu64(in[1], 8);
+    result |= shlu64(in[2], 16);
+    result |= shlu64(in[3], 24);
     
     return result;
 }
@@ -119,37 +119,37 @@ void sc_reduce(unsigned char *s) {
     s18 = 0;
     carry6 = (s6 + (1 << 20)) >> 21;
     s7 += carry6;
-    s6 -= carry6 << 21;
+    s6 -= shl64(carry6, 21);
     carry8 = (s8 + (1 << 20)) >> 21;
     s9 += carry8;
-    s8 -= carry8 << 21;
+    s8 -= shl64(carry8, 21);
     carry10 = (s10 + (1 << 20)) >> 21;
     s11 += carry10;
-    s10 -= carry10 << 21;
+    s10 -= shl64(carry10, 21);
     carry12 = (s12 + (1 << 20)) >> 21;
     s13 += carry12;
-    s12 -= carry12 << 21;
+    s12 -= shl64(carry12, 21);
     carry14 = (s14 + (1 << 20)) >> 21;
     s15 += carry14;
-    s14 -= carry14 << 21;
+    s14 -= shl64(carry14, 21);
     carry16 = (s16 + (1 << 20)) >> 21;
     s17 += carry16;
-    s16 -= carry16 << 21;
+    s16 -= shl64(carry16, 21);
     carry7 = (s7 + (1 << 20)) >> 21;
     s8 += carry7;
-    s7 -= carry7 << 21;
+    s7 -= shl64(carry7, 21);
     carry9 = (s9 + (1 << 20)) >> 21;
     s10 += carry9;
-    s9 -= carry9 << 21;
+    s9 -= shl64(carry9, 21);
     carry11 = (s11 + (1 << 20)) >> 21;
     s12 += carry11;
-    s11 -= carry11 << 21;
+    s11 -= shl64(carry11, 21);
     carry13 = (s13 + (1 << 20)) >> 21;
     s14 += carry13;
-    s13 -= carry13 << 21;
+    s13 -= shl64(carry13, 21);
     carry15 = (s15 + (1 << 20)) >> 21;
     s16 += carry15;
-    s15 -= carry15 << 21;
+    s15 -= shl64(carry15, 21);
     s5 += s17 * 666643;
     s6 += s17 * 470296;
     s7 += s17 * 654183;
@@ -194,40 +194,40 @@ void sc_reduce(unsigned char *s) {
     s12 = 0;
     carry0 = (s0 + (1 << 20)) >> 21;
     s1 += carry0;
-    s0 -= carry0 << 21;
+    s0 -= shl64(carry0, 21);
     carry2 = (s2 + (1 << 20)) >> 21;
     s3 += carry2;
-    s2 -= carry2 << 21;
+    s2 -= shl64(carry2, 21);
     carry4 = (s4 + (1 << 20)) >> 21;
     s5 += carry4;
-    s4 -= carry4 << 21;
+    s4 -= shl64(carry4, 21);
     carry6 = (s6 + (1 << 20)) >> 21;
     s7 += carry6;
-    s6 -= carry6 << 21;
+    s6 -= shl64(carry6, 21);
     carry8 = (s8 + (1 << 20)) >> 21;
     s9 += carry8;
-    s8 -= carry8 << 21;
+    s8 -= shl64(carry8, 21);
     carry10 = (s10 + (1 << 20)) >> 21;
     s11 += carry10;
-    s10 -= carry10 << 21;
+    s10 -= shl64(carry10, 21);
     carry1 = (s1 + (1 << 20)) >> 21;
     s2 += carry1;
-    s1 -= carry1 << 21;
+    s1 -= shl64(carry1, 21);
     carry3 = (s3 + (1 << 20)) >> 21;
     s4 += carry3;
-    s3 -= carry3 << 21;
+    s3 -= shl64(carry3, 21);
     carry5 = (s5 + (1 << 20)) >> 21;
     s6 += carry5;
-    s5 -= carry5 << 21;
+    s5 -= shl64(carry5, 21);
     carry7 = (s7 + (1 << 20)) >> 21;
     s8 += carry7;
-    s7 -= carry7 << 21;
+    s7 -= shl64(carry7, 21);
     carry9 = (s9 + (1 << 20)) >> 21;
     s10 += carry9;
-    s9 -= carry9 << 21;
+    s9 -= shl64(carry9, 21);
     carry11 = (s11 + (1 << 20)) >> 21;
     s12 += carry11;
-    s11 -= carry11 << 21;
+    s11 -= shl64(carry11, 21);
     s0 += s12 * 666643;
     s1 += s12 * 470296;
     s2 += s12 * 654183;
@@ -237,40 +237,40 @@ void sc_reduce(unsigned char *s) {
     s12 = 0;
     carry0 = s0 >> 21;
     s1 += carry0;
-    s0 -= carry0 << 21;
+    s0 -= shl64(carry0, 21);
     carry1 = s1 >> 21;
     s2 += carry1;
-    s1 -= carry1 << 21;
+    s1 -= shl64(carry1, 21);
     carry2 = s2 >> 21;
     s3 += carry2;
-    s2 -= carry2 << 21;
+    s2 -= shl64(carry2, 21);
     carry3 = s3 >> 21;
     s4 += carry3;
-    s3 -= carry3 << 21;
+    s3 -= shl64(carry3, 21);
     carry4 = s4 >> 21;
     s5 += carry4;
-    s4 -= carry4 << 21;
+    s4 -= shl64(carry4, 21);
     carry5 = s5 >> 21;
     s6 += carry5;
-    s5 -= carry5 << 21;
+    s5 -= shl64(carry5, 21);
     carry6 = s6 >> 21;
     s7 += carry6;
-    s6 -= carry6 << 21;
+    s6 -= shl64(carry6, 21);
     carry7 = s7 >> 21;
     s8 += carry7;
-    s7 -= carry7 << 21;
+    s7 -= shl64(carry7, 21);
     carry8 = s8 >> 21;
     s9 += carry8;
-    s8 -= carry8 << 21;
+    s8 -= shl64(carry8, 21);
     carry9 = s9 >> 21;
     s10 += carry9;
-    s9 -= carry9 << 21;
+    s9 -= shl64(carry9, 21);
     carry10 = s10 >> 21;
     s11 += carry10;
-    s10 -= carry10 << 21;
+    s10 -= shl64(carry10, 21);
     carry11 = s11 >> 21;
     s12 += carry11;
-    s11 -= carry11 << 21;
+    s11 -= shl64(carry11, 21);
     s0 += s12 * 666643;
     s1 += s12 * 470296;
     s2 += s12 * 654183;
@@ -280,67 +280,67 @@ void sc_reduce(unsigned char *s) {
     s12 = 0;
     carry0 = s0 >> 21;
     s1 += carry0;
-    s0 -= carry0 << 21;
+    s0 -= shl64(carry0, 21);
     carry1 = s1 >> 21;
     s2 += carry1;
-    s1 -= carry1 << 21;
+    s1 -= shl64(carry1, 21);
     carry2 = s2 >> 21;
     s3 += carry2;
-    s2 -= carry2 << 21;
+    s2 -= shl64(carry2, 21);
     carry3 = s3 >> 21;
     s4 += carry3;
-    s3 -= carry3 << 21;
+    s3 -= shl64(carry3, 21);
     carry4 = s4 >> 21;
     s5 += carry4;
-    s4 -= carry4 << 21;
+    s4 -= shl64(carry4, 21);
     carry5 = s5 >> 21;
     s6 += carry5;
-    s5 -= carry5 << 21;
+    s5 -= shl64(carry5, 21);
     carry6 = s6 >> 21;
     s7 += carry6;
-    s6 -= carry6 << 21;
+    s6 -= shl64(carry6, 21);
     carry7 = s7 >> 21;
     s8 += carry7;
-    s7 -= carry7 << 21;
+    s7 -= shl64(carry7, 21);
     carry8 = s8 >> 21;
     s9 += carry8;
-    s8 -= carry8 << 21;
+    s8 -= shl64(carry8, 21);
     carry9 = s9 >> 21;
     s10 += carry9;
-    s9 -= carry9 << 21;
+    s9 -= shl64(carry9, 21);
     carry10 = s10 >> 21;
     s11 += carry10;
-    s10 -= carry10 << 21;
+    s10 -= shl64(carry10, 21);
 
     s[0] = (unsigned char) (s0 >> 0);
     s[1] = (unsigned char) (s0 >> 8);
-    s[2] = (unsigned char) ((s0 >> 16) | (s1 << 5));
+    s[2] = (unsigned char) ((s0 >> 16) | shl64(s1, 5));
     s[3] = (unsigned char) (s1 >> 3);
     s[4] = (unsigned char) (s1 >> 11);
-    s[5] = (unsigned char) ((s1 >> 19) | (s2 << 2));
+    s[5] = (unsigned char) ((s1 >> 19) | shl64(s2, 2));
     s[6] = (unsigned char) (s2 >> 6);
-    s[7] = (unsigned char) ((s2 >> 14) | (s3 << 7));
+    s[7] = (unsigned char) ((s2 >> 14) | shl64(s3, 7));
     s[8] = (unsigned char) (s3 >> 1);
     s[9] = (unsigned char) (s3 >> 9);
-    s[10] = (unsigned char) ((s3 >> 17) | (s4 << 4));
+    s[10] = (unsigned char) ((s3 >> 17) | shl64(s4, 4));
     s[11] = (unsigned char) (s4 >> 4);
     s[12] = (unsigned char) (s4 >> 12);
-    s[13] = (unsigned char) ((s4 >> 20) | (s5 << 1));
+    s[13] = (unsigned char) ((s4 >> 20) | shl64(s5, 1));
     s[14] = (unsigned char) (s5 >> 7);
-    s[15] = (unsigned char) ((s5 >> 15) | (s6 << 6));
+    s[15] = (unsigned char) ((s5 >> 15) | shl64(s6, 6));
     s[16] = (unsigned char) (s6 >> 2);
     s[17] = (unsigned char) (s6 >> 10);
-    s[18] = (unsigned char) ((s6 >> 18) | (s7 << 3));
+    s[18] = (unsigned char) ((s6 >> 18) | shl64(s7, 3));
     s[19] = (unsigned char) (s7 >> 5);
     s[20] = (unsigned char) (s7 >> 13);
     s[21] = (unsigned char) (s8 >> 0);
     s[22] = (unsigned char) (s8 >> 8);
-    s[23] = (unsigned char) ((s8 >> 16) | (s9 << 5));
+    s[23] = (unsigned char) ((s8 >> 16) | shl64(s9, 5));
     s[24] = (unsigned char) (s9 >> 3);
     s[25] = (unsigned char) (s9 >> 11);
-    s[26] = (unsigned char) ((s9 >> 19) | (s10 << 2));
+    s[26] = (unsigned char) ((s9 >> 19) | shl64(s10, 2));
     s[27] = (unsigned char) (s10 >> 6);
-    s[28] = (unsigned char) ((s10 >> 14) | (s11 << 7));
+    s[28] = (unsigned char) ((s10 >> 14) | shl64(s11, 7));
     s[29] = (unsigned char) (s11 >> 1);
     s[30] = (unsigned char) (s11 >> 9);
     s[31] = (unsigned char) (s11 >> 17);
@@ -470,73 +470,73 @@ void sc_muladd(unsigned char *s, const unsigned char *a, const unsigned char *b,
     s23 = 0;
     carry0 = (s0 + (1 << 20)) >> 21;
     s1 += carry0;
-    s0 -= carry0 << 21;
+    s0 -= shl64(carry0, 21);
     carry2 = (s2 + (1 << 20)) >> 21;
     s3 += carry2;
-    s2 -= carry2 << 21;
+    s2 -= shl64(carry2, 21);
     carry4 = (s4 + (1 << 20)) >> 21;
     s5 += carry4;
-    s4 -= carry4 << 21;
+    s4 -= shl64(carry4, 21);
     carry6 = (s6 + (1 << 20)) >> 21;
     s7 += carry6;
-    s6 -= carry6 << 21;
+    s6 -= shl64(carry6, 21);
     carry8 = (s8 + (1 << 20)) >> 21;
     s9 += carry8;
-    s8 -= carry8 << 21;
+    s8 -= shl64(carry8, 21);
     carry10 = (s10 + (1 << 20)) >> 21;
     s11 += carry10;
-    s10 -= carry10 << 21;
+    s10 -= shl64(carry10, 21);
     carry12 = (s12 + (1 << 20)) >> 21;
     s13 += carry12;
-    s12 -= carry12 << 21;
+    s12 -= shl64(carry12, 21);
     carry14 = (s14 + (1 << 20)) >> 21;
     s15 += carry14;
-    s14 -= carry14 << 21;
+    s14 -= shl64(carry14, 21);
     carry16 = (s16 + (1 << 20)) >> 21;
     s17 += carry16;
-    s16 -= carry16 << 21;
+    s16 -= shl64(carry16, 21);
     carry18 = (s18 + (1 << 20)) >> 21;
     s19 += carry18;
-    s18 -= carry18 << 21;
+    s18 -= shl64(carry18, 21);
     carry20 = (s20 + (1 << 20)) >> 21;
     s21 += carry20;
-    s20 -= carry20 << 21;
+    s20 -= shl64(carry20, 21);
     carry22 = (s22 + (1 << 20)) >> 21;
     s23 += carry22;
-    s22 -= carry22 << 21;
+    s22 -= shl64(carry22, 21);
     carry1 = (s1 + (1 << 20)) >> 21;
     s2 += carry1;
-    s1 -= carry1 << 21;
+    s1 -= shl64(carry1, 21);
     carry3 = (s3 + (1 << 20)) >> 21;
     s4 += carry3;
-    s3 -= carry3 << 21;
+    s3 -= shl64(carry3, 21);
     carry5 = (s5 + (1 << 20)) >> 21;
     s6 += carry5;
-    s5 -= carry5 << 21;
+    s5 -= shl64(carry5, 21);
     carry7 = (s7 + (1 << 20)) >> 21;
     s8 += carry7;
-    s7 -= carry7 << 21;
+    s7 -= shl64(carry7, 21);
     carry9 = (s9 + (1 << 20)) >> 21;
     s10 += carry9;
-    s9 -= carry9 << 21;
+    s9 -= shl64(carry9, 21);
     carry11 = (s11 + (1 << 20)) >> 21;
     s12 += carry11;
-    s11 -= carry11 << 21;
+    s11 -= shl64(carry11, 21);
     carry13 = (s13 + (1 << 20)) >> 21;
     s14 += carry13;
-    s13 -= carry13 << 21;
+    s13 -= shl64(carry13, 21);
     carry15 = (s15 + (1 << 20)) >> 21;
     s16 += carry15;
-    s15 -= carry15 << 21;
+    s15 -= shl64(carry15, 21);
     carry17 = (s17 + (1 << 20)) >> 21;
     s18 += carry17;
-    s17 -= carry17 << 21;
+    s17 -= shl64(carry17, 21);
     carry19 = (s19 + (1 << 20)) >> 21;
     s20 += carry19;
-    s19 -= carry19 << 21;
+    s19 -= shl64(carry19, 21);
     carry21 = (s21 + (1 << 20)) >> 21;
     s22 += carry21;
-    s21 -= carry21 << 21;
+    s21 -= shl64(carry21, 21);
     s11 += s23 * 666643;
     s12 += s23 * 470296;
     s13 += s23 * 654183;
@@ -581,37 +581,37 @@ void sc_muladd(unsigned char *s, const unsigned char *a, const unsigned char *b,
     s18 = 0;
     carry6 = (s6 + (1 << 20)) >> 21;
     s7 += carry6;
-    s6 -= carry6 << 21;
+    s6 -= shl64(carry6, 21);
     carry8 = (s8 + (1 << 20)) >> 21;
     s9 += carry8;
-    s8 -= carry8 << 21;
+    s8 -= shl64(carry8, 21);
     carry10 = (s10 + (1 << 20)) >> 21;
     s11 += carry10;
-    s10 -= carry10 << 21;
+    s10 -= shl64(carry10, 21);
     carry12 = (s12 + (1 << 20)) >> 21;
     s13 += carry12;
-    s12 -= carry12 << 21;
+    s12 -= shl64(carry12, 21);
     carry14 = (s14 + (1 << 20)) >> 21;
     s15 += carry14;
-    s14 -= carry14 << 21;
+    s14 -= shl64(carry14, 21);
     carry16 = (s16 + (1 << 20)) >> 21;
     s17 += carry16;
-    s16 -= carry16 << 21;
+    s16 -= shl64(carry16, 21);
     carry7 = (s7 + (1 << 20)) >> 21;
     s8 += carry7;
-    s7 -= carry7 << 21;
+    s7 -= shl64(carry7, 21);
     carry9 = (s9 + (1 << 20)) >> 21;
     s10 += carry9;
-    s9 -= carry9 << 21;
+    s9 -= shl64(carry9, 21);
     carry11 = (s11 + (1 << 20)) >> 21;
     s12 += carry11;
-    s11 -= carry11 << 21;
+    s11 -= shl64(carry11, 21);
     carry13 = (s13 + (1 << 20)) >> 21;
     s14 += carry13;
-    s13 -= carry13 << 21;
+    s13 -= shl64(carry13, 21);
     carry15 = (s15 + (1 << 20)) >> 21;
     s16 += carry15;
-    s15 -= carry15 << 21;
+    s15 -= shl64(carry15, 21);
     s5 += s17 * 666643;
     s6 += s17 * 470296;
     s7 += s17 * 654183;
@@ -656,40 +656,40 @@ void sc_muladd(unsigned char *s, const unsigned char *a, const unsigned char *b,
     s12 = 0;
     carry0 = (s0 + (1 << 20)) >> 21;
     s1 += carry0;
-    s0 -= carry0 << 21;
+    s0 -= shl64(carry0, 21);
     carry2 = (s2 + (1 << 20)) >> 21;
     s3 += carry2;
-    s2 -= carry2 << 21;
+    s2 -= shl64(carry2, 21);
     carry4 = (s4 + (1 << 20)) >> 21;
     s5 += carry4;
-    s4 -= carry4 << 21;
+    s4 -= shl64(carry4, 21);
     carry6 = (s6 + (1 << 20)) >> 21;
     s7 += carry6;
-    s6 -= carry6 << 21;
+    s6 -= shl64(carry6, 21);
     carry8 = (s8 + (1 << 20)) >> 21;
     s9 += carry8;
-    s8 -= carry8 << 21;
+    s8 -= shl64(carry8, 21);
     carry10 = (s10 + (1 << 20)) >> 21;
     s11 += carry10;
-    s10 -= carry10 << 21;
+    s10 -= shl64(carry10, 21);
     carry1 = (s1 + (1 << 20)) >> 21;
     s2 += carry1;
-    s1 -= carry1 << 21;
+    s1 -= shl64(carry1, 21);
     carry3 = (s3 + (1 << 20)) >> 21;
     s4 += carry3;
-    s3 -= carry3 << 21;
+    s3 -= shl64(carry3, 21);
     carry5 = (s5 + (1 << 20)) >> 21;
     s6 += carry5;
-    s5 -= carry5 << 21;
+    s5 -= shl64(carry5, 21);
     carry7 = (s7 + (1 << 20)) >> 21;
     s8 += carry7;
-    s7 -= carry7 << 21;
+    s7 -= shl64(carry7, 21);
     carry9 = (s9 + (1 << 20)) >> 21;
     s10 += carry9;
-    s9 -= carry9 << 21;
+    s9 -= shl64(carry9, 21);
     carry11 = (s11 + (1 << 20)) >> 21;
     s12 += carry11;
-    s11 -= carry11 << 21;
+    s11 -= shl64(carry11, 21);
     s0 += s12 * 666643;
     s1 += s12 * 470296;
     s2 += s12 * 654183;
@@ -699,40 +699,40 @@ void sc_muladd(unsigned char *s, const unsigned char *a, const unsigned char *b,
     s12 = 0;
     carry0 = s0 >> 21;
     s1 += carry0;
-    s0 -= carry0 << 21;
+    s0 -= shl64(carry0, 21);
     carry1 = s1 >> 21;
     s2 += carry1;
-    s1 -= carry1 << 21;
+    s1 -= shl64(carry1, 21);
     carry2 = s2 >> 21;
     s3 += carry2;
-    s2 -= carry2 << 21;
+    s2 -= shl64(carry2, 21);
     carry3 = s3 >> 21;
     s4 += carry3;
-    s3 -= carry3 << 21;
+    s3 -= shl64(carry3, 21);
     carry4 = s4 >> 21;
     s5 += carry4;
-    s4 -= carry4 << 21;
+    s4 -= shl64(carry4, 21);
     carry5 = s5 >> 21;
     s6 += carry5;
-    s5 -= carry5 << 21;
+    s5 -= shl64(carry5, 21);
     carry6 = s6 >> 21;
     s7 += carry6;
-    s6 -= carry6 << 21;
+    s6 -= shl64(carry6, 21);
     carry7 = s7 >> 21;
     s8 += carry7;
-    s7 -= carry7 << 21;
+    s7 -= shl64(carry7, 21);
     carry8 = s8 >> 21;
     s9 += carry8;
-    s8 -= carry8 << 21;
+    s8 -= shl64(carry8, 21);
     carry9 = s9 >> 21;
     s10 += carry9;
-    s9 -= carry9 << 21;
+    s9 -= shl64(carry9, 21);
     carry10 = s10 >> 21;
     s11 += carry10;
-    s10 -= carry10 << 21;
+    s10 -= shl64(carry10, 21);
     carry11 = s11 >> 21;
     s12 += carry11;
-    s11 -= carry11 << 21;
+    s11 -= shl64(carry11, 21);
     s0 += s12 * 666643;
     s1 += s12 * 470296;
     s2 += s12 * 654183;
@@ -742,67 +742,67 @@ void sc_muladd(unsigned char *s, const unsigned char *a, const unsigned char *b,
     s12 = 0;
     carry0 = s0 >> 21;
     s1 += carry0;
-    s0 -= carry0 << 21;
+    s0 -= shl64(carry0, 21);
     carry1 = s1 >> 21;
     s2 += carry1;
-    s1 -= carry1 << 21;
+    s1 -= shl64(carry1, 21);
     carry2 = s2 >> 21;
     s3 += carry2;
-    s2 -= carry2 << 21;
+    s2 -= shl64(carry2, 21);
     carry3 = s3 >> 21;
     s4 += carry3;
-    s3 -= carry3 << 21;
+    s3 -= shl64(carry3, 21);
     carry4 = s4 >> 21;
     s5 += carry4;
-    s4 -= carry4 << 21;
+    s4 -= shl64(carry4, 21);
     carry5 = s5 >> 21;
     s6 += carry5;
-    s5 -= carry5 << 21;
+    s5 -= shl64(carry5, 21);
     carry6 = s6 >> 21;
     s7 += carry6;
-    s6 -= carry6 << 21;
+    s6 -= shl64(carry6, 21);
     carry7 = s7 >> 21;
     s8 += carry7;
-    s7 -= carry7 << 21;
+    s7 -= shl64(carry7, 21);
     carry8 = s8 >> 21;
     s9 += carry8;
-    s8 -= carry8 << 21;
+    s8 -= shl64(carry8, 21);
     carry9 = s9 >> 21;
     s10 += carry9;
-    s9 -= carry9 << 21;
+    s9 -= shl64(carry9, 21);
     carry10 = s10 >> 21;
     s11 += carry10;
-    s10 -= carry10 << 21;
+    s10 -= shl64(carry10, 21);
     
     s[0] = (unsigned char) (s0 >> 0);
     s[1] = (unsigned char) (s0 >> 8);
-    s[2] = (unsigned char) ((s0 >> 16) | (s1 << 5));
+    s[2] = (unsigned char) ((s0 >> 16) | shl64(s1, 5));
     s[3] = (unsigned char) (s1 >> 3);
     s[4] = (unsigned char) (s1 >> 11);
-    s[5] = (unsigned char) ((s1 >> 19) | (s2 << 2));
+    s[5] = (unsigned char) ((s1 >> 19) | shl64(s2, 2));
     s[6] = (unsigned char) (s2 >> 6);
-    s[7] = (unsigned char) ((s2 >> 14) | (s3 << 7));
+    s[7] = (unsigned char) ((s2 >> 14) | shl64(s3, 7));
     s[8] = (unsigned char) (s3 >> 1);
     s[9] = (unsigned char) (s3 >> 9);
-    s[10] = (unsigned char) ((s3 >> 17) | (s4 << 4));
+    s[10] = (unsigned char) ((s3 >> 17) | shl64(s4, 4));
     s[11] = (unsigned char) (s4 >> 4);
     s[12] = (unsigned char) (s4 >> 12);
-    s[13] = (unsigned char) ((s4 >> 20) | (s5 << 1));
+    s[13] = (unsigned char) ((s4 >> 20) | shl64(s5, 1));
     s[14] = (unsigned char) (s5 >> 7);
-    s[15] = (unsigned char) ((s5 >> 15) | (s6 << 6));
+    s[15] = (unsigned char) ((s5 >> 15) | shl64(s6, 6));
     s[16] = (unsigned char) (s6 >> 2);
     s[17] = (unsigned char) (s6 >> 10);
-    s[18] = (unsigned char) ((s6 >> 18) | (s7 << 3));
+    s[18] = (unsigned char) ((s6 >> 18) | shl64(s7, 3));
     s[19] = (unsigned char) (s7 >> 5);
     s[20] = (unsigned char) (s7 >> 13);
     s[21] = (unsigned char) (s8 >> 0);
     s[22] = (unsigned char) (s8 >> 8);
-    s[23] = (unsigned char) ((s8 >> 16) | (s9 << 5));
+    s[23] = (unsigned char) ((s8 >> 16) | shl64(s9, 5));
     s[24] = (unsigned char) (s9 >> 3);
     s[25] = (unsigned char) (s9 >> 11);
-    s[26] = (unsigned char) ((s9 >> 19) | (s10 << 2));
+    s[26] = (unsigned char) ((s9 >> 19) | shl64(s10, 2));
     s[27] = (unsigned char) (s10 >> 6);
-    s[28] = (unsigned char) ((s10 >> 14) | (s11 << 7));
+    s[28] = (unsigned char) ((s10 >> 14) | shl64(s11, 7));
     s[29] = (unsigned char) (s11 >> 1);
     s[30] = (unsigned char) (s11 >> 9);
     s[31] = (unsigned char) (s11 >> 17);
diff --git a/src/node.h b/src/node.h
index ec5f83c1..87767993 100644
--- a/src/node.h
+++ b/src/node.h
@@ -39,10 +39,10 @@ typedef struct node_status_t {
 	unsigned int udp_confirmed:1;           /* 1 if the address is one that we received UDP traffic on */
 	unsigned int send_locally:1;		/* 1 if the next UDP packet should be sent on the local network */
 	unsigned int udppacket:1;		/* 1 if the most recently received packet was UDP */
-	unsigned int validkey_in;		/* 1 if we have sent a valid key to him */
+	unsigned int validkey_in:1;		/* 1 if we have sent a valid key to him */
 	unsigned int has_known_address;					/* 1 if this node has UDP Address */
 	unsigned int has_cfg_address;           /* 1 if this node has Address in node's config */
-	unsigned int unused:19;
+	unsigned int unused:21;
 } node_status_t;
 
 typedef struct node_t {
diff --git a/src/route.c b/src/route.c
index 2baabdf2..9f7e1508 100644
--- a/src/route.c
+++ b/src/route.c
@@ -164,7 +164,7 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac
 		/* Found it */
 		uint16_t oldmss = DATA(packet)[start + 22 + i] << 8 | DATA(packet)[start + 23 + i];
 		uint16_t newmss = mtu - start - 20;
-		uint16_t csum = DATA(packet)[start + 16] << 8 | DATA(packet)[start + 17];
+		uint32_t csum = DATA(packet)[start + 16] << 8 | DATA(packet)[start + 17];
 
 		if(oldmss <= newmss)
 			break;
@@ -175,11 +175,13 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac
 		DATA(packet)[start + 22 + i] = newmss >> 8;
 		DATA(packet)[start + 23 + i] = newmss & 0xff;
 		csum ^= 0xffff;
-		csum -= oldmss;
+		csum += oldmss ^ 0xffff;
 		csum += newmss;
+		csum = (csum & 0xffff) + (csum >> 16);
+		csum += csum >> 16;
 		csum ^= 0xffff;
 		DATA(packet)[start + 16] = csum >> 8;
-		DATA(packet)[start + 17] = csum & 0xff;
+		DATA(packet)[start + 17] = csum;
 		break;
 	}
 }
diff --git a/src/tincctl.c b/src/tincctl.c
index cdcf8388..13ecbc25 100644
--- a/src/tincctl.c
+++ b/src/tincctl.c
@@ -416,6 +416,7 @@ static bool ed25519_keygen(bool ask) {
 
 	char *pubkey = ecdsa_get_base64_public_key(key);
 	fprintf(f, "Ed25519PublicKey = %s\n", pubkey);
+	free(pubkey);
 
 	fclose(f);
 	ecdsa_free(key);
@@ -1810,7 +1811,7 @@ static int cmd_config(int argc, char *argv[]) {
 }
 
 static bool try_bind(int port) {
-	struct addrinfo *ai = NULL;
+	struct addrinfo *ai = NULL, *aip;
 	struct addrinfo hint = {
 		.ai_flags = AI_PASSIVE,
 		.ai_family = AF_UNSPEC,
@@ -1818,24 +1819,30 @@ static bool try_bind(int port) {
 		.ai_protocol = IPPROTO_TCP,
 	};
 
+	bool success = true;
 	char portstr[16];
 	snprintf(portstr, sizeof portstr, "%d", port);
 
 	if(getaddrinfo(NULL, portstr, &hint, &ai) || !ai)
 		return false;
 
-	while(ai) {
+	for(aip = ai; aip; aip = aip->ai_next) {
 		int fd = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
-		if(!fd)
-			return false;
+		if(!fd) {
+			success = false;
+			break;
+		}
+
 		int result = bind(fd, ai->ai_addr, ai->ai_addrlen);
 		closesocket(fd);
-		if(result)
-			return false;
-		ai = ai->ai_next;
+		if(result) {
+			success = false;
+			break;
+		}
 	}
 
-	return true;
+	freeaddrinfo(ai);
+	return success;
 }
 
 int check_port(char *name) {
diff --git a/systemd/Makefile.am b/systemd/Makefile.am
new file mode 100644
index 00000000..a1bfe124
--- /dev/null
+++ b/systemd/Makefile.am
@@ -0,0 +1,4 @@
+if WITH_SYSTEMD
+systemddir = @systemd_path@
+dist_systemd_DATA = tinc.service tinc@.service
+endif
diff --git a/systemd/tinc.service b/systemd/tinc.service
new file mode 100644
index 00000000..d911fa78
--- /dev/null
+++ b/systemd/tinc.service
@@ -0,0 +1,20 @@
+# This is a mostly empty service, but allows commands like stop, start, reload
+# to propagate to all tinc@ service instances.
+
+[Unit]
+Description=Tinc VPN
+Documentation=info:tinc
+Documentation=man:tinc(8) man:tinc.conf(5)
+Documentation=http://tinc-vpn.org/docs/
+After=network.target
+Wants=network.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=/bin/true
+ExecReload=/bin/true
+WorkingDirectory=/etc/tinc
+
+[Install]
+WantedBy=multi-user.target
diff --git a/systemd/tinc@.service b/systemd/tinc@.service
new file mode 100644
index 00000000..78ef25b1
--- /dev/null
+++ b/systemd/tinc@.service
@@ -0,0 +1,19 @@
+[Unit]
+Description=Tinc net %i
+Documentation=info:tinc
+Documentation=man:tinc(8) man:tinc.conf(5)
+Documentation=http://tinc-vpn.org/docs/
+PartOf=tinc.service
+ReloadPropagatedFrom=tinc.service
+
+[Service]
+Type=simple
+WorkingDirectory=/etc/tinc/%i
+ExecStart=/usr/sbin/tincd -n %i -D
+ExecReload=/usr/sbin/tinc -n %i reload
+Restart=on-failure
+RestartSec=5
+TimeoutStopSec=5
+
+[Install]
+WantedBy=tinc.service