Merge pull request #385

0a4bc84 Added ref10 shen_ed25519_ref code, which includes code that can replace crypto-ops with a version straight from Bernstein's ref 10 (ShenNoether)
0d70fdc revert to 776b4fc91a821be152f0f23e6873aabb78a72029 (ShenNoether)
b01f286 Added shen_ed25519_ref to crypto ops subfolder, the point is to directly have bitmonero's crypto code come from bernstein et al's ref 10 code (ShenNoether)

1 files changed, 16 insertions, 0 deletions

diff --git a/src/crypto/shen_ed25519_ref/ref10CommentedCombined/fe_isnegative.c b/src/crypto/shen_ed25519_ref/ref10CommentedCombined/fe_isnegative.c
new file mode 100644
index 000000000..3b2c8b8d5
--- /dev/null
+++ b/src/crypto/shen_ed25519_ref/ref10CommentedCombined/fe_isnegative.c
@@ -0,0 +1,16 @@
+#include "fe.h"
+
+/*
+return 1 if f is in {1,3,5,...,q-2}
+return 0 if f is in {0,2,4,...,q-1}
+
+Preconditions:
+   |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
+*/
+
+int fe_isnegative(const fe f)
+{
+  unsigned char s[32];
+  fe_tobytes(s,f);
+  return s[0] & 1;
+}