From 2e59f9740a29439df7c7a56cf0ae83dec3081d31 Mon Sep 17 00:00:00 2001 From: Micah Anderson Date: Mon, 11 Aug 2014 13:49:21 -0400 Subject: initial import of debian version from mentors --- src/libsodium/crypto_sign/ed25519/ref10/fe_cmov.c | 63 +++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 src/libsodium/crypto_sign/ed25519/ref10/fe_cmov.c (limited to 'src/libsodium/crypto_sign/ed25519/ref10/fe_cmov.c') diff --git a/src/libsodium/crypto_sign/ed25519/ref10/fe_cmov.c b/src/libsodium/crypto_sign/ed25519/ref10/fe_cmov.c new file mode 100644 index 0000000..8ca584f --- /dev/null +++ b/src/libsodium/crypto_sign/ed25519/ref10/fe_cmov.c @@ -0,0 +1,63 @@ +#include "fe.h" + +/* +Replace (f,g) with (g,g) if b == 1; +replace (f,g) with (f,g) if b == 0. + +Preconditions: b in {0,1}. +*/ + +void fe_cmov(fe f,const fe g,unsigned int b) +{ + 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 g0 = g[0]; + crypto_int32 g1 = g[1]; + crypto_int32 g2 = g[2]; + crypto_int32 g3 = g[3]; + crypto_int32 g4 = g[4]; + crypto_int32 g5 = g[5]; + crypto_int32 g6 = g[6]; + crypto_int32 g7 = g[7]; + crypto_int32 g8 = g[8]; + crypto_int32 g9 = g[9]; + crypto_int32 x0 = f0 ^ g0; + crypto_int32 x1 = f1 ^ g1; + crypto_int32 x2 = f2 ^ g2; + crypto_int32 x3 = f3 ^ g3; + crypto_int32 x4 = f4 ^ g4; + crypto_int32 x5 = f5 ^ g5; + crypto_int32 x6 = f6 ^ g6; + crypto_int32 x7 = f7 ^ g7; + crypto_int32 x8 = f8 ^ g8; + crypto_int32 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; +} -- cgit v1.2.3