diff options
Diffstat (limited to 'crypto/src/math/ec/custom/sec/Nat256.cs')
| -rw-r--r-- | crypto/src/math/ec/custom/sec/Nat256.cs | 148 |
1 files changed, 113 insertions, 35 deletions
diff --git a/crypto/src/math/ec/custom/sec/Nat256.cs b/crypto/src/math/ec/custom/sec/Nat256.cs index beb9ab5ed..335c181fa 100644 --- a/crypto/src/math/ec/custom/sec/Nat256.cs +++ b/crypto/src/math/ec/custom/sec/Nat256.cs @@ -69,6 +69,17 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec return (uint)c; } + public static uint Add33To(uint x, uint[] z) + { + ulong c = (ulong)z[0] + x; + z[0] = (uint)c; + c >>= 32; + c += (ulong)z[1] + 1; + z[1] = (uint)c; + c >>= 32; + return c == 0 ? 0 : Inc(z, 2); + } + public static uint AddBothTo(uint[] x, uint[] y, uint[] z) { ulong c = 0; @@ -129,18 +140,16 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec return (uint)c; } - // TODO Re-write to allow full range for x? - public static uint AddDWord(ulong x, uint[] z, int zOff) + public static uint AddDWordAt(ulong x, uint[] z, int zPos) { - Debug.Assert(zOff <= 6); - ulong c = x; - c += (ulong)z[zOff + 0]; - z[zOff + 0] = (uint)c; + Debug.Assert(zPos <= 6); + ulong c = (ulong)z[zPos + 0] + (x & M); + z[zPos + 0] = (uint)c; c >>= 32; - c += (ulong)z[zOff + 1]; - z[zOff + 1] = (uint)c; + c += (ulong)z[zPos + 1] + (x >> 32); + z[zPos + 1] = (uint)c; c >>= 32; - return c == 0 ? 0 : Inc(z, zOff + 2); + return c == 0 ? 0 : Inc(z, zPos + 2); } public static uint AddExt(uint[] xx, uint[] yy, uint[] zz) @@ -155,6 +164,36 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec return (uint)c; } + public static uint AddTo(uint[] x, uint[] z) + { + ulong c = 0; + c += (ulong)x[ 0] + z[ 0]; + z[ 0] = (uint)c; + c >>= 32; + c += (ulong)x[ 1] + z[ 1]; + z[ 1] = (uint)c; + c >>= 32; + c += (ulong)x[ 2] + z[ 2]; + z[ 2] = (uint)c; + c >>= 32; + c += (ulong)x[ 3] + z[ 3]; + z[ 3] = (uint)c; + c >>= 32; + c += (ulong)x[ 4] + z[ 4]; + z[ 4] = (uint)c; + c >>= 32; + c += (ulong)x[ 5] + z[ 5]; + z[ 5] = (uint)c; + c >>= 32; + c += (ulong)x[ 6] + z[ 6]; + z[ 6] = (uint)c; + c >>= 32; + c += (ulong)x[ 7] + z[ 7]; + z[ 7] = (uint)c; + c >>= 32; + return (uint)c; + } + public static uint AddTo(uint[] x, int xOff, uint[] z, int zOff, uint cIn) { ulong c = cIn; @@ -1298,6 +1337,17 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec return (int)c; } + public static int Sub33From(uint x, uint[] z) + { + long c = (long)z[0] - x; + z[0] = (uint)c; + c >>= 32; + c += (long)z[1] - 1; + z[1] = (uint)c; + c >>= 32; + return c == 0 ? 0 : Dec(z, 2); + } + public static int SubBothFrom(uint[] x, uint[] y, uint[] z) { long c = 0; @@ -1328,17 +1378,16 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec return (int)c; } - // TODO Re-write to allow full range for x? - public static int SubDWord(ulong x, uint[] z) + public static int SubDWordAt(ulong x, uint[] z, int zPos) { - long c = -(long)x; - c += (long)z[0]; - z[0] = (uint)c; + Debug.Assert(zPos <= 6); + long c = (long)z[zPos + 0] - (long)(x & M); + z[zPos + 0] = (uint)c; c >>= 32; - c += (long)z[1]; - z[1] = (uint)c; + c += (long)z[zPos + 1] - (long)(x >> 32); + z[zPos + 1] = (uint)c; c >>= 32; - return c == 0 ? 0 : Dec(z, 2); + return c == 0 ? 0 : Dec(z, zPos + 2); } public static int SubExt(uint[] xx, uint[] yy, uint[] zz) @@ -1353,33 +1402,62 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec return (int)c; } - public static int SubFromExt(uint[] x, int xOff, uint[] zz, int zzOff) + public static int SubFrom(uint[] x, uint[] z) { - Debug.Assert(zzOff <= 8); long c = 0; - c += (long)zz[zzOff + 0] - x[xOff + 0]; - zz[zzOff + 0] = (uint)c; + c += (long)z[0] - x[0]; + z[0] = (uint)c; + c >>= 32; + c += (long)z[1] - x[1]; + z[1] = (uint)c; c >>= 32; - c += (long)zz[zzOff + 1] - x[xOff + 1]; - zz[zzOff + 1] = (uint)c; + c += (long)z[2] - x[2]; + z[2] = (uint)c; c >>= 32; - c += (long)zz[zzOff + 2] - x[xOff + 2]; - zz[zzOff + 2] = (uint)c; + c += (long)z[3] - x[3]; + z[3] = (uint)c; c >>= 32; - c += (long)zz[zzOff + 3] - x[xOff + 3]; - zz[zzOff + 3] = (uint)c; + c += (long)z[4] - x[4]; + z[4] = (uint)c; c >>= 32; - c += (long)zz[zzOff + 4] - x[xOff + 4]; - zz[zzOff + 4] = (uint)c; + c += (long)z[5] - x[5]; + z[5] = (uint)c; c >>= 32; - c += (long)zz[zzOff + 5] - x[xOff + 5]; - zz[zzOff + 5] = (uint)c; + c += (long)z[6] - x[6]; + z[6] = (uint)c; c >>= 32; - c += (long)zz[zzOff + 6] - x[xOff + 6]; - zz[zzOff + 6] = (uint)c; + c += (long)z[7] - x[7]; + z[7] = (uint)c; c >>= 32; - c += (long)zz[zzOff + 7] - x[xOff + 7]; - zz[zzOff + 7] = (uint)c; + return (int)c; + } + + public static int SubFrom(uint[] x, int xOff, uint[] z, int zOff) + { + long c = 0; + c += (long)z[zOff + 0] - x[xOff + 0]; + z[zOff + 0] = (uint)c; + c >>= 32; + c += (long)z[zOff + 1] - x[xOff + 1]; + z[zOff + 1] = (uint)c; + c >>= 32; + c += (long)z[zOff + 2] - x[xOff + 2]; + z[zOff + 2] = (uint)c; + c >>= 32; + c += (long)z[zOff + 3] - x[xOff + 3]; + z[zOff + 3] = (uint)c; + c >>= 32; + c += (long)z[zOff + 4] - x[xOff + 4]; + z[zOff + 4] = (uint)c; + c >>= 32; + c += (long)z[zOff + 5] - x[xOff + 5]; + z[zOff + 5] = (uint)c; + c >>= 32; + c += (long)z[zOff + 6] - x[xOff + 6]; + z[zOff + 6] = (uint)c; + c >>= 32; + c += (long)z[zOff + 7] - x[xOff + 7]; + z[zOff + 7] = (uint)c; c >>= 32; return (int)c; } |