python-crypto: fixed endianness detection

This fixes setup.py so that it uses the endianness of the target system
instead of detecting endianness from the host. This affects the
computation of RIPEMD-160 hashes.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

lang/python-crypto/Makefile

@@ -37,7 +37,10 @@ and various encryption algorithms (AES, DES, IDEA, RSA, ElGamal, etc.).
 endef
 
 define Build/Compile
-	$(call Build/Compile/PyMod,,install --prefix=/usr --root=$(PKG_INSTALL_DIR))
+	$(call Build/Compile/PyMod,,\
+		install --prefix=/usr --root=$(PKG_INSTALL_DIR),\
+		CONFIG_BIG_ENDIAN="$(CONFIG_BIG_ENDIAN)" \
+	)
 endef
 
 define Package/python-crypto/install

lang/python-crypto/patches/002-fix-endianness-detect.patch

@@ -0,0 +1,15 @@
+--- a/setup.py	2015-10-30 23:30:22.334127083 +0800
++++ b/setup.py	2015-10-30 23:33:03.856098660 +0800
+@@ -100,6 +100,12 @@
+         w(kwd.get("end", "\n"))
+ 
+ def endianness_macro():
++    if "CONFIG_BIG_ENDIAN" in os.environ:
++        if os.environ["CONFIG_BIG_ENDIAN"] == "y":
++            return ('PCT_BIG_ENDIAN', 1)
++        else:
++            return ('PCT_LITTLE_ENDIAN', 1)
++    raise AssertionError("CONFIG_BIG_ENDIAN environment variable missing")
+     s = struct.pack("@I", 0x33221100)
+     if s == "\x00\x11\x22\x33".encode():     # little endian
+         return ('PCT_LITTLE_ENDIAN', 1)