commit files needed for zpm-fetchurl

[zpackage] / crypto / ref10 / fe_cswap.c

diff --git a/crypto/ref10/fe_cswap.c b/crypto/ref10/fe_cswap.c
new file mode 100644 (file)
index 0000000..242d3fc
--- /dev/null
+++ b/crypto/ref10/fe_cswap.c
@@ -0,0 +1,72 @@
+#include <stdint.h>
+
+/*
+Replace (f,g) with (g,f) if b == 1;
+replace (f,g) with (f,g) if b == 0.
+
+Preconditions: b in {0,1}.
+*/
+
+void fe_cswap(int32_t f[10], int32_t g[10], unsigned int b) {
+       int32_t f0 = f[0];
+       int32_t f1 = f[1];
+       int32_t f2 = f[2];
+       int32_t f3 = f[3];
+       int32_t f4 = f[4];
+       int32_t f5 = f[5];
+       int32_t f6 = f[6];
+       int32_t f7 = f[7];
+       int32_t f8 = f[8];
+       int32_t f9 = f[9];
+       int32_t g0 = g[0];
+       int32_t g1 = g[1];
+       int32_t g2 = g[2];
+       int32_t g3 = g[3];
+       int32_t g4 = g[4];
+       int32_t g5 = g[5];
+       int32_t g6 = g[6];
+       int32_t g7 = g[7];
+       int32_t g8 = g[8];
+       int32_t g9 = g[9];
+       int32_t x0 = f0 ^ g0;
+       int32_t x1 = f1 ^ g1;
+       int32_t x2 = f2 ^ g2;
+       int32_t x3 = f3 ^ g3;
+       int32_t x4 = f4 ^ g4;
+       int32_t x5 = f5 ^ g5;
+       int32_t x6 = f6 ^ g6;
+       int32_t x7 = f7 ^ g7;
+       int32_t x8 = f8 ^ g8;
+       int32_t x9 = f9 ^ g9;
+       b = -b;
+       x0 &= b;
+       x1 &= b;
+       x2 &= b;
+       x3 &= b;
+       x4 &= b;
+       x5 &= b;
+       x6 &= b;
+       x7 &= b;
+       x8 &= b;
+       x9 &= b;
+       f[0] = f0 ^ x0;
+       f[1] = f1 ^ x1;
+       f[2] = f2 ^ x2;
+       f[3] = f3 ^ x3;
+       f[4] = f4 ^ x4;
+       f[5] = f5 ^ x5;
+       f[6] = f6 ^ x6;
+       f[7] = f7 ^ x7;
+       f[8] = f8 ^ x8;
+       f[9] = f9 ^ x9;
+       g[0] = g0 ^ x0;
+       g[1] = g1 ^ x1;
+       g[2] = g2 ^ x2;
+       g[3] = g3 ^ x3;
+       g[4] = g4 ^ x4;
+       g[5] = g5 ^ x5;
+       g[6] = g6 ^ x6;
+       g[7] = g7 ^ x7;
+       g[8] = g8 ^ x8;
+       g[9] = g9 ^ x9;
+}