1 files changed, 27 insertions, 0 deletions
diff --git a/cipher/arcfour.c b/cipher/arcfour.c
index d692c84a..27537bfd 100644
--- a/cipher/arcfour.c
+++ b/cipher/arcfour.c
@@ -31,8 +31,33 @@
 #include "g10lib.h"
 #include "cipher.h"
 
+/* USE_AMD64_ASM indicates whether to use AMD64 assembly code. */
+#undef USE_AMD64_ASM
+#if defined(__x86_64__) && defined(HAVE_COMPATIBLE_GCC_AMD64_PLATFORM_AS)
+# define USE_AMD64_ASM 1
+#endif
+
 static const char *selftest(void);
 
+#ifdef USE_AMD64_ASM
+
+typedef struct {
+    u32 sbox[256];
+    u32 idx_i, idx_j;
+} ARCFOUR_context;
+
+void _gcry_arcfour_amd64(void *key, size_t len, const byte *indata,
+			 byte *outdata);
+
+static void
+encrypt_stream (void *context,
+                byte *outbuf, const byte *inbuf, size_t length)
+{
+  _gcry_arcfour_amd64 (context, length, inbuf, outbuf );
+}
+
+#else /*!USE_AMD64_ASM*/
+
 typedef struct {
     byte sbox[256];
     int idx_i, idx_j;
@@ -96,6 +121,8 @@ encrypt_stream (void *context,
   _gcry_burn_stack (64);
 }
 
+#endif /*!USE_AMD64_ASM*/
+
 
 static gcry_err_code_t
 do_arcfour_setkey (void *context, const byte *key, unsigned int keylen)