1 files changed, 45 insertions, 0 deletions
diff --git a/libs/libaxolotl/src/curve25519/ed25519/fe_neg.c b/libs/libaxolotl/src/curve25519/ed25519/fe_neg.c
new file mode 100644
index 0000000000..2078ce5284
--- /dev/null
+++ b/libs/libaxolotl/src/curve25519/ed25519/fe_neg.c
@@ -0,0 +1,45 @@
+#include "fe.h"
+
+/*
+h = -f
+
+Preconditions:
+   |f| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+
+Postconditions:
+   |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+*/
+
+void fe_neg(fe h,const fe f)
+{
+  crypto_int32 f0 = f[0];
+  crypto_int32 f1 = f[1];
+  crypto_int32 f2 = f[2];
+  crypto_int32 f3 = f[3];
+  crypto_int32 f4 = f[4];
+  crypto_int32 f5 = f[5];
+  crypto_int32 f6 = f[6];
+  crypto_int32 f7 = f[7];
+  crypto_int32 f8 = f[8];
+  crypto_int32 f9 = f[9];
+  crypto_int32 h0 = -f0;
+  crypto_int32 h1 = -f1;
+  crypto_int32 h2 = -f2;
+  crypto_int32 h3 = -f3;
+  crypto_int32 h4 = -f4;
+  crypto_int32 h5 = -f5;
+  crypto_int32 h6 = -f6;
+  crypto_int32 h7 = -f7;
+  crypto_int32 h8 = -f8;
+  crypto_int32 h9 = -f9;
+  h[0] = h0;
+  h[1] = h1;
+  h[2] = h2;
+  h[3] = h3;
+  h[4] = h4;
+  h[5] = h5;
+  h[6] = h6;
+  h[7] = h7;
+  h[8] = h8;
+  h[9] = h9;
+}