diff options
Diffstat (limited to 'crypto/src/math/ec/Nat.cs')
| -rw-r--r-- | crypto/src/math/ec/Nat.cs | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/crypto/src/math/ec/Nat.cs b/crypto/src/math/ec/Nat.cs new file mode 100644 index 000000000..cc8996dfc --- /dev/null +++ b/crypto/src/math/ec/Nat.cs @@ -0,0 +1,495 @@ +using System; + +using Org.BouncyCastle.Crypto.Utilities; +using Org.BouncyCastle.Math; + +namespace Org.BouncyCastle.Math.EC +{ + internal abstract class Nat + { + public static uint Add(int len, uint[] x, uint[] y, uint[] z) + { + ulong c = 0; + for (int i = 0; i < len; ++i) + { + c += (ulong)x[i] + y[i]; + z[i] = (uint)c; + c >>= 32; + } + return (uint)c; + } + + public static uint AddBothTo(int len, uint[] x, uint[] y, uint[] z) + { + ulong c = 0; + for (int i = 0; i < len; ++i) + { + c += (ulong)x[i] + y[i] + z[i]; + z[i] = (uint)c; + c >>= 32; + } + return (uint)c; + } + + public static uint AddDWord(int len, ulong x, uint[] z, int zOff) + { + // assert zOff < (len - 2); + ulong c = x; + c += (ulong)z[zOff + 0]; + z[zOff + 0] = (uint)c; + c >>= 32; + c += (ulong)z[zOff + 1]; + z[zOff + 1] = (uint)c; + c >>= 32; + return c == 0 ? 0 : Inc(len, z, zOff + 2); + } + + public static uint AddExt(int len, uint[] xx, uint[] yy, uint[] zz) + { + int extLen = len << 1; + ulong c = 0; + for (int i = 0; i < extLen; ++i) + { + c += (ulong)xx[i] + yy[i]; + zz[i] = (uint)c; + c >>= 32; + } + return (uint)c; + } + + public static uint AddToExt(int len, uint[] x, int xOff, uint[] zz, int zzOff) + { + // assert zzOff <= len; + ulong c = 0; + for (int i = 0; i < len; ++i) + { + c += (ulong)x[xOff + i] + zz[zzOff + i]; + zz[zzOff + i] = (uint)c; + c >>= 32; + } + return (uint)c; + } + + public static uint AddWordExt(int len, uint x, uint[] zz, int zzOff) + { + // assert zzOff < ((len << 1) - 1); + ulong c = (ulong)x + zz[zzOff]; + zz[zzOff] = (uint)c; + c >>= 32; + return c == 0 ? 0 : IncExt(len, zz, zzOff + 1); + } + + public static uint[] Copy(int len, uint[] x) + { + uint[] z = new uint[len]; + Array.Copy(x, 0, z, 0, len); + return z; + } + + public static uint[] Create(int len) + { + return new uint[len]; + } + + public static uint[] CreateExt(int len) + { + int extLen = len << 1; + return new uint[extLen]; + } + + public static int Dec(int len, uint[] z, int zOff) + { + // assert zOff < len; + int i = zOff; + do + { + if (--z[i] != uint.MaxValue) + { + return 0; + } + } + while (++i < len); + return -1; + } + + public static uint[] FromBigInteger(int len, BigInteger x) + { + if (x.SignValue < 0 || x.BitLength > (len << 5)) + throw new ArgumentException(); + + uint[] z = Create(len); + int i = 0; + while (x.SignValue != 0) + { + z[i++] = (uint)x.IntValue; + x = x.ShiftRight(32); + } + return z; + } + + public static uint GetBit(uint[] x, int bit) + { + if (bit == 0) + { + return x[0] & 1; + } + uint w = (uint)bit >> 5; + int b = bit & 31; + return (x[w] >> b) & 1; + } + + public static bool Gte(int len, uint[] x, uint[] y) + { + for (int i = len - 1; i >= 0; --i) + { + uint x_i = x[i], y_i = y[i]; + if (x_i < y_i) + return false; + if (x_i > y_i) + return true; + } + return false; + } + + public static bool GteExt(int len, uint[] xx, uint[] yy) + { + int extLen = len << 1; + for (int i = extLen - 1; i >= 0; --i) + { + uint xx_i = xx[i], yy_i = yy[i]; + if (xx_i < yy_i) + return false; + if (xx_i > yy_i) + return true; + } + return false; + } + + public static uint Inc(int len, uint[] z, int zOff) + { + // assert zOff < len; + for (int i = zOff; i < len; ++i) + { + if (++z[i] != 0) + { + return 0; + } + } + return 1; + } + + public static uint IncExt(int len, uint[] zz, int zzOff) + { + int extLen = len; + // assert zzOff < extLen; + for (int i = zzOff; i < extLen; ++i) + { + if (++zz[i] != 0) + { + return 0; + } + } + return 1; + } + + public static bool IsOne(int len, uint[] x) + { + if (x[0] != 1) + { + return false; + } + for (int i = 1; i < len; ++i) + { + if (x[i] != 0) + { + return false; + } + } + return true; + } + + public static bool IsZero(int len, uint[] x) + { + if (x[0] != 0) + { + return false; + } + for (int i = 1; i < len; ++i) + { + if (x[i] != 0) + { + return false; + } + } + return true; + } + + public static bool isZeroExt(int len, uint[] xx) + { + if (xx[0] != 0) + { + return false; + } + int extLen = len << 1; + for (int i = 1; i < extLen; ++i) + { + if (xx[i] != 0) + { + return false; + } + } + return true; + } + + public static void Mul(int len, uint[] x, uint[] y, uint[] zz) + { + zz[len] = (uint)MulWordExt(len, x[0], y, zz, 0); + + for (int i = 1; i < len; ++i) + { + zz[i + len] = (uint)MulWordAddExt(len, x[i], y, 0, zz, i); + } + } + + public static uint MulWordAddExt(int len, uint x, uint[] yy, int yyOff, uint[] zz, int zzOff) + { + // assert yyOff <= len; + // assert zzOff <= len; + ulong c = 0, xVal = (ulong)x; + int i = 0; + do + { + c += xVal * yy[yyOff + i] + zz[zzOff + i]; + zz[zzOff + i] = (uint)c; + c >>= 32; + } + while (++i < len); + return (uint)c; + } + + public static uint SquareWordAddExt(int len, uint[] x, int xPos, uint[] zz) + { + // assert xPos > 0 && xPos < len; + ulong c = 0, xVal = (ulong)x[xPos]; + int i = 0; + do + { + c += xVal * x[i] + zz[xPos + i]; + zz[xPos + i] = (uint)c; + c >>= 32; + } + while (++i < xPos); + return (uint)c; + } + + public static uint MulWordDwordAdd(int len, uint x, ulong y, uint[] z, int zOff) + { + // assert zOff < (len - 3); + ulong c = 0, xVal = (ulong)x; + c += xVal * (uint)y + z[zOff + 0]; + z[zOff + 0] = (uint)c; + c >>= 32; + c += xVal * (y >> 32) + z[zOff + 1]; + z[zOff + 1] = (uint)c; + c >>= 32; + c += (ulong)z[zOff + 2]; + z[zOff + 2] = (uint)c; + c >>= 32; + return c == 0 ? 0 : Inc(len, z, zOff + 3); + } + + public static uint MulWordExt(int len, uint x, uint[] y, uint[] zz, int zzOff) + { + // assert zzOff <= len; + ulong c = 0, xVal = (ulong)x; + int i = 0; + do + { + c += xVal * y[i]; + zz[zzOff + i] = (uint)c; + c >>= 32; + } + while (++i < len); + return (uint)c; + } + + public static uint ShiftDownBit(uint[] x, int xLen, uint c) + { + int i = xLen; + while (--i >= 0) + { + uint next = x[i]; + x[i] = (next >> 1) | (c << 31); + c = next; + } + return c << 31; + } + + public static uint ShiftDownBit(int len, uint[] x, uint c, uint[] z) + { + int i = len; + while (--i >= 0) + { + uint next = x[i]; + z[i] = (next >> 1) | (c << 31); + c = next; + } + return c << 31; + } + + public static uint ShiftDownBits(uint[] x, int xLen, int bits, uint c) + { + //assert bits > 0 && bits < 32; + int i = xLen; + while (--i >= 0) + { + uint next = x[i]; + x[i] = (next >> bits) | (c << -bits); + c = next; + } + return c << 32 - bits; + } + + public static uint ShiftDownWord(uint[] x, int xLen, uint c) + { + int i = xLen; + while (--i >= 0) + { + uint next = x[i]; + x[i] = c; + c = next; + } + return c; + } + + public static uint ShiftUpBit(uint[] x, int xLen, uint c) + { + for (int i = 0; i < xLen; ++i) + { + uint next = x[i]; + x[i] = (next << 1) | (c >> 31); + c = next; + } + return c >> 31; + } + + public static uint ShiftUpBit(int len, uint[] x, uint c, uint[] z) + { + for (int i = 0; i < len; ++i) + { + uint next = x[i]; + z[i] = (next << 1) | (c >> 31); + c = next; + } + return c >> 31; + } + + public static void Square(int len, uint[] x, uint[] zz) + { + int extLen = len << 1; + uint c = 0; + int j = len, k = extLen; + do + { + ulong xVal = (ulong)x[--j]; + ulong p = xVal * xVal; + zz[--k] = (c << 31) | (uint)(p >> 33); + zz[--k] = (uint)(p >> 1); + c = (uint)p; + } + while (j > 0); + + for (int i = 1; i < len; ++i) + { + c = SquareWordAddExt(len, x, i, zz); + AddWordExt(len, c, zz, i << 1); + } + + ShiftUpBit(zz, extLen, x[0] << 31); + } + + public static int Sub(int len, uint[] x, uint[] y, uint[] z) + { + long c = 0; + for (int i = 0; i < len; ++i) + { + c += (long)x[i] - y[i]; + z[i] = (uint)c; + c >>= 32; + } + return (int)c; + } + + public static int SubBothFrom(int len, uint[] x, uint[] y, uint[] z) + { + long c = 0; + for (int i = 0; i < len; ++i) + { + c += (long)z[i] - x[i] - y[i]; + z[i] = (uint)c; + c >>= 32; + } + return (int)c; + } + + public static int SubDWord(int len, ulong x, uint[] z) + { + long c = -(long)x; + c += (long)z[0]; + z[0] = (uint)c; + c >>= 32; + c += (long)z[1]; + z[1] = (uint)c; + c >>= 32; + return c == 0 ? 0 : Dec(len, z, 2); + } + + public static int SubExt(int len, uint[] xx, uint[] yy, uint[] zz) + { + int extLen = len << 1; + long c = 0; + for (int i = 0; i < extLen; ++i) + { + c += (long)xx[i] - yy[i]; + zz[i] = (uint)c; + c >>= 32; + } + return (int)c; + } + + public static uint SubFromExt(int len, uint[] x, int xOff, uint[] zz, int zzOff) + { + // assert zzOff <= len; + ulong c = 0; + for (int i = 0; i < len; ++i) + { + c += (ulong)zz[zzOff + i] - x[xOff + i]; + zz[zzOff + i] = (uint)c; + c >>= 32; + } + return (uint)c; + } + + public static BigInteger ToBigInteger(int len, uint[] x) + { + byte[] bs = new byte[len << 2]; + for (int i = 0; i < len; ++i) + { + uint x_i = x[i]; + if (x_i != 0) + { + Pack.UInt32_To_BE(x_i, bs, (len - 1 - i) << 2); + } + } + return new BigInteger(1, bs); + } + + public static void Zero(int len, uint[] z) + { + for (int i = 0; i < len; ++i) + { + z[i] = 0; + } + } + } +} |