Merge branch 'ntor-resquashed'

Conflicts:
	src/or/cpuworker.c
	src/or/or.h
	src/test/bench.c

1 files changed, 99 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index df56efd5e..adcfdb4fb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,6 +36,8 @@ AC_ARG_ENABLE(static-zlib,
    AS_HELP_STRING(--enable-static-zlib, Link against a static zlib library. Requires --with-zlib-dir))
 AC_ARG_ENABLE(static-tor,
    AS_HELP_STRING(--enable-static-tor, Create an entirely static Tor binary. Requires --with-openssl-dir and --with-libevent-dir and --with-zlib-dir))
+AC_ARG_ENABLE(curve25519,
+   AS_HELP_STRING(--disable-curve25519, Build Tor with no curve25519 elliptic-curve crypto support))
 
 if test "$enable_static_tor" = "yes"; then
   enable_static_libevent="yes";
@@ -639,6 +641,103 @@ if test "$upnp" = "true"; then
     fi
 fi
 
+dnl ============================================================
+dnl We need an implementation of curve25519.
+
+dnl set these defaults.
+have_a_curve25519=no
+build_curve25519_donna=no
+build_curve25519_donna_c64=no
+use_curve25519_donna=no
+use_curve25519_nacl=no
+CURVE25519_LIBS=
+
+if test x$enable_curve25519 != xno; then
+
+  dnl The best choice is using curve25519-donna-c64, but that requires
+  dnl that we
+  AC_CACHE_CHECK([whether we can use curve25519-donna-c64],
+    tor_cv_can_use_curve25519_donna_c64,
+    [AC_RUN_IFELSE(
+      [AC_LANG_PROGRAM([dnl
+        #include <stdint.h>
+        typedef unsigned uint128_t __attribute__((mode(TI)));
+	], [dnl
+          uint64_t a = ((uint64_t)2000000000) * 1000000000;
+	  uint64_t b = ((uint64_t)1234567890) << 24;
+	  uint128_t c = ((uint128_t)a) * b;
+	  return ((uint64_t)(c>>96)) == 522859 &&
+	         ((uint64_t)(c>>64))&0xffffffffL == 3604448702L &&
+                 ((uint64_t)(c>>32))&0xffffffffL == 2351960064L &&
+                 ((uint64_t)(c))&0xffffffffL == 0;
+        ])],
+	[tor_cv_can_use_curve25519_donna_c64=yes],
+        [tor_cv_can_use_curve25519_donna_c64=no],
+	[AC_COMPILE_IFELSE(
+          [AC_LANG_PROGRAM([dnl
+            #include <stdint.h>
+            typedef unsigned uint128_t __attribute__((mode(TI)));
+            ], [dnl
+              uint64_t a = ((uint64_t)2000000000) * 1000000000;
+	      uint64_t b = ((uint64_t)1234567890) << 24;
+	      uint128_t c = ((uint128_t)a) * b;
+	      return ((uint64_t)(c>>96)) == 522859 &&
+	             ((uint64_t)(c>>64))&0xffffffffL == 3604448702L &&
+                     ((uint64_t)(c>>32))&0xffffffffL == 2351960064L &&
+                     ((uint64_t)(c))&0xffffffffL == 0;
+            ])],
+            [tor_cv_can_use_curve25519_donna_c64=cross],
+	    [tor_cv_can_use_curve25519_donna_c64=no])])])
+
+  AC_CACHE_CHECK([whether we can use curve25519 from nacl],
+    tor_cv_can_use_curve25519_nacl,
+    [tor_saved_LIBS="$LIBS"
+     LIBS="$LIBS -lnacl"
+     AC_LINK_IFELSE(
+       [AC_LANG_PROGRAM([dnl
+         #include <crypto_scalarmult_curve25519.h>
+         #ifdef crypto_scalarmult_curve25519_ref_BYTES
+	 #error Hey, this is the reference implementation!
+	 #endif
+       ], [
+	 unsigned char *a, *b, *c; crypto_scalarmult_curve25519(a,b,c);
+       ])], [tor_cv_can_use_curve25519_nacl=yes],
+       [tor_cv_can_use_curve25519_nacl=no])
+     LIBS="$tor_saved_LIBS" ])
+
+   dnl Okay, now we need to figure out which one to actually use. Fall back
+   dnl to curve25519-donna.c
+
+   if test x$tor_cv_can_use_curve25519_donna_c64 != xno; then
+     build_curve25519_donna_c64=yes
+     use_curve25519_donna=yes
+   elif test x$tor_cv_can_use_curve25519_nacl = xyes; then
+     use_curve25519_nacl=yes
+     CURVE25519_LIBS=-lnacl
+   else
+     build_curve25519_donna=yes
+     use_curve25519_donna=yes
+   fi
+   have_a_curve25519=yes
+fi
+
+if test x$have_a_curve25519 = xyes; then
+  AC_DEFINE(CURVE25519_ENABLED, 1,
+            [Defined if we have a curve25519 implementation])
+fi
+if test x$use_curve25519_donna = xyes; then
+  AC_DEFINE(USE_CURVE25519_DONNA, 1,
+            [Defined if we should use an internal curve25519_donna{,_c64} implementation])
+fi
+if test x$use_curve25519_nacl = xyes; then
+  AC_DEFINE(USE_CURVE25519_NACL, 1,
+            [Defined if we should use a curve25519 from nacl])
+fi
+AM_CONDITIONAL(BUILD_CURVE25519_DONNA, test x$build_curve25519_donna = xyes)
+AM_CONDITIONAL(BUILD_CURVE25519_DONNA_C64, test x$build_curve25519_donna_c64 = xyes)
+AM_CONDITIONAL(CURVE25519_ENABLED, test x$have_a_curve25519 = xyes)
+AC_SUBST(CURVE25519_LIBS)
+
 dnl Make sure to enable support for large off_t if available.
 AC_SYS_LARGEFILE