1 files changed, 23 insertions, 0 deletions

diff --git a/nacl/crypto_stream/xsalsa20/ref/xor.c b/nacl/crypto_stream/xsalsa20/ref/xor.c
new file mode 100644
index 00000000..13f3134a
--- /dev/null
+++ b/nacl/crypto_stream/xsalsa20/ref/xor.c
@@ -0,0 +1,23 @@
+/*
+version 20080913
+D. J. Bernstein
+Public domain.
+*/
+
+#include "crypto_core_hsalsa20.h"
+#include "crypto_stream_salsa20.h"
+#include "crypto_stream.h"
+
+static const unsigned char sigma[16] = "expand 32-byte k";
+
+int crypto_stream_xor(
+        unsigned char *c,
+  const unsigned char *m,unsigned long long mlen,
+  const unsigned char *n,
+  const unsigned char *k
+)
+{
+  unsigned char subkey[32];
+  crypto_core_hsalsa20(subkey,n,k,sigma);
+  return crypto_stream_salsa20_xor(c,m,mlen,n + 16,subkey);
+}