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author | Andrew Arnott <andrewarnott@gmail.com> | 2012-01-29 14:32:45 -0800 |
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committer | Andrew Arnott <andrewarnott@gmail.com> | 2012-01-29 14:32:45 -0800 |
commit | 5fec515095ee10b522f414a03e78f282aaf520dc (patch) | |
tree | 204c75486639c23cdda2ef38b34d7e5050a1a2e3 /src/Mono.Math/BigInteger.cs | |
parent | f1a4155398635a4fd9f485eec817152627682704 (diff) | |
parent | 8f4165ee515728aca3faaa26e8354a40612e85e4 (diff) | |
download | DotNetOpenAuth-5fec515095ee10b522f414a03e78f282aaf520dc.zip DotNetOpenAuth-5fec515095ee10b522f414a03e78f282aaf520dc.tar.gz DotNetOpenAuth-5fec515095ee10b522f414a03e78f282aaf520dc.tar.bz2 |
Merge branch 'splitDlls'.
DNOA now builds and (in some cases) ships as many distinct assemblies.
Diffstat (limited to 'src/Mono.Math/BigInteger.cs')
-rw-r--r-- | src/Mono.Math/BigInteger.cs | 2241 |
1 files changed, 2241 insertions, 0 deletions
diff --git a/src/Mono.Math/BigInteger.cs b/src/Mono.Math/BigInteger.cs new file mode 100644 index 0000000..33df8df --- /dev/null +++ b/src/Mono.Math/BigInteger.cs @@ -0,0 +1,2241 @@ +// <auto-generated /> + +// +// BigInteger.cs - Big Integer implementation +// +// Authors: +// Ben Maurer +// Chew Keong TAN +// Sebastien Pouliot (spouliot@motus.com) +// +// Copyright (c) 2003 Ben Maurer +// All rights reserved +// +// Copyright (c) 2002 Chew Keong TAN +// All rights reserved. +// +// Modified 2007 Andrew Arnott (http://blog.nerdbank.net) +// Rewrote unsafe code as safe code. + +using System; +using System.Security.Cryptography; +using Mono.Math.Prime; +using Mono.Math.Prime.Generator; + +namespace Mono.Math { + + internal class BigInteger { + + #region Data Storage + + /// <summary> + /// The Length of this BigInteger + /// </summary> + uint length = 1; + + /// <summary> + /// The data for this BigInteger + /// </summary> + uint [] data; + + #endregion + + #region Constants + + /// <summary> + /// Default length of a BigInteger in bytes + /// </summary> + const uint DEFAULT_LEN = 20; + + /// <summary> + /// Table of primes below 2000. + /// </summary> + /// <remarks> + /// <para> + /// This table was generated using Mathematica 4.1 using the following function: + /// </para> + /// <para> + /// <code> + /// PrimeTable [x_] := Prime [Range [1, PrimePi [x]]] + /// PrimeTable [6000] + /// </code> + /// </para> + /// </remarks> + public static readonly uint [] smallPrimes = { + 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, + 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, + 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, + 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, + 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, + 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, + 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, + 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, + 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, + 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, + 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997, + + 1009, 1013, 1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1087, + 1091, 1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181, + 1187, 1193, 1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249, 1259, 1277, 1279, + 1283, 1289, 1291, 1297, 1301, 1303, 1307, 1319, 1321, 1327, 1361, 1367, 1373, + 1381, 1399, 1409, 1423, 1427, 1429, 1433, 1439, 1447, 1451, 1453, 1459, 1471, + 1481, 1483, 1487, 1489, 1493, 1499, 1511, 1523, 1531, 1543, 1549, 1553, 1559, + 1567, 1571, 1579, 1583, 1597, 1601, 1607, 1609, 1613, 1619, 1621, 1627, 1637, + 1657, 1663, 1667, 1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733, 1741, 1747, + 1753, 1759, 1777, 1783, 1787, 1789, 1801, 1811, 1823, 1831, 1847, 1861, 1867, + 1871, 1873, 1877, 1879, 1889, 1901, 1907, 1913, 1931, 1933, 1949, 1951, 1973, + 1979, 1987, 1993, 1997, 1999, + + 2003, 2011, 2017, 2027, 2029, 2039, 2053, 2063, 2069, 2081, 2083, 2087, 2089, + 2099, 2111, 2113, 2129, 2131, 2137, 2141, 2143, 2153, 2161, 2179, 2203, 2207, + 2213, 2221, 2237, 2239, 2243, 2251, 2267, 2269, 2273, 2281, 2287, 2293, 2297, + 2309, 2311, 2333, 2339, 2341, 2347, 2351, 2357, 2371, 2377, 2381, 2383, 2389, + 2393, 2399, 2411, 2417, 2423, 2437, 2441, 2447, 2459, 2467, 2473, 2477, 2503, + 2521, 2531, 2539, 2543, 2549, 2551, 2557, 2579, 2591, 2593, 2609, 2617, 2621, + 2633, 2647, 2657, 2659, 2663, 2671, 2677, 2683, 2687, 2689, 2693, 2699, 2707, + 2711, 2713, 2719, 2729, 2731, 2741, 2749, 2753, 2767, 2777, 2789, 2791, 2797, + 2801, 2803, 2819, 2833, 2837, 2843, 2851, 2857, 2861, 2879, 2887, 2897, 2903, + 2909, 2917, 2927, 2939, 2953, 2957, 2963, 2969, 2971, 2999, + + 3001, 3011, 3019, 3023, 3037, 3041, 3049, 3061, 3067, 3079, 3083, 3089, 3109, + 3119, 3121, 3137, 3163, 3167, 3169, 3181, 3187, 3191, 3203, 3209, 3217, 3221, + 3229, 3251, 3253, 3257, 3259, 3271, 3299, 3301, 3307, 3313, 3319, 3323, 3329, + 3331, 3343, 3347, 3359, 3361, 3371, 3373, 3389, 3391, 3407, 3413, 3433, 3449, + 3457, 3461, 3463, 3467, 3469, 3491, 3499, 3511, 3517, 3527, 3529, 3533, 3539, + 3541, 3547, 3557, 3559, 3571, 3581, 3583, 3593, 3607, 3613, 3617, 3623, 3631, + 3637, 3643, 3659, 3671, 3673, 3677, 3691, 3697, 3701, 3709, 3719, 3727, 3733, + 3739, 3761, 3767, 3769, 3779, 3793, 3797, 3803, 3821, 3823, 3833, 3847, 3851, + 3853, 3863, 3877, 3881, 3889, 3907, 3911, 3917, 3919, 3923, 3929, 3931, 3943, + 3947, 3967, 3989, + + 4001, 4003, 4007, 4013, 4019, 4021, 4027, 4049, 4051, 4057, 4073, 4079, 4091, + 4093, 4099, 4111, 4127, 4129, 4133, 4139, 4153, 4157, 4159, 4177, 4201, 4211, + 4217, 4219, 4229, 4231, 4241, 4243, 4253, 4259, 4261, 4271, 4273, 4283, 4289, + 4297, 4327, 4337, 4339, 4349, 4357, 4363, 4373, 4391, 4397, 4409, 4421, 4423, + 4441, 4447, 4451, 4457, 4463, 4481, 4483, 4493, 4507, 4513, 4517, 4519, 4523, + 4547, 4549, 4561, 4567, 4583, 4591, 4597, 4603, 4621, 4637, 4639, 4643, 4649, + 4651, 4657, 4663, 4673, 4679, 4691, 4703, 4721, 4723, 4729, 4733, 4751, 4759, + 4783, 4787, 4789, 4793, 4799, 4801, 4813, 4817, 4831, 4861, 4871, 4877, 4889, + 4903, 4909, 4919, 4931, 4933, 4937, 4943, 4951, 4957, 4967, 4969, 4973, 4987, + 4993, 4999, + + 5003, 5009, 5011, 5021, 5023, 5039, 5051, 5059, 5077, 5081, 5087, 5099, 5101, + 5107, 5113, 5119, 5147, 5153, 5167, 5171, 5179, 5189, 5197, 5209, 5227, 5231, + 5233, 5237, 5261, 5273, 5279, 5281, 5297, 5303, 5309, 5323, 5333, 5347, 5351, + 5381, 5387, 5393, 5399, 5407, 5413, 5417, 5419, 5431, 5437, 5441, 5443, 5449, + 5471, 5477, 5479, 5483, 5501, 5503, 5507, 5519, 5521, 5527, 5531, 5557, 5563, + 5569, 5573, 5581, 5591, 5623, 5639, 5641, 5647, 5651, 5653, 5657, 5659, 5669, + 5683, 5689, 5693, 5701, 5711, 5717, 5737, 5741, 5743, 5749, 5779, 5783, 5791, + 5801, 5807, 5813, 5821, 5827, 5839, 5843, 5849, 5851, 5857, 5861, 5867, 5869, + 5879, 5881, 5897, 5903, 5923, 5927, 5939, 5953, 5981, 5987 + }; + + public enum Sign : int { + Negative = -1, + Zero = 0, + Positive = 1 + }; + + #region Exception Messages + const string WouldReturnNegVal = "Operation would return a negative value"; + #endregion + + #endregion + + #region Constructors + + public BigInteger () + { + data = new uint [DEFAULT_LEN]; + } + public BigInteger (Sign sign, uint len) + { + this.data = new uint [len]; + this.length = len; + } + + public BigInteger (BigInteger bi) + { + this.data = (uint [])bi.data.Clone (); + this.length = bi.length; + } + + public BigInteger (BigInteger bi, uint len) + { + + this.data = new uint [len]; + + for (uint i = 0; i < bi.length; i++) + this.data [i] = bi.data [i]; + + this.length = bi.length; + } + + #endregion + + public static BigInteger Parse(string number) { + if (number == null) + throw new ArgumentNullException(number); + int i = 0, len = number.Length; + char c; + bool digits_seen = false; + BigInteger val = new BigInteger(0); + if (number[i] == '+') { + i++; + } else if(number[i] == '-') { + throw new FormatException("Only positive integers are allowed."); + } + for(; i < len; i++) { + c = number[i]; + if (c == '\0') { + i = len; + continue; + } + if (c >= '0' && c <= '9'){ + val = val * 10 + (c - '0'); + digits_seen = true; + } else { + if (Char.IsWhiteSpace(c)){ + for (i++; i < len; i++){ + if (!Char.IsWhiteSpace (number[i])) + throw new FormatException(); + } + break; + } else + throw new FormatException(); + } + } + if (!digits_seen) + throw new FormatException(); + return val; + } + + #region Conversions + + public BigInteger (byte [] inData) + { + length = (uint)inData.Length >> 2; + int leftOver = inData.Length & 0x3; + + // length not multiples of 4 + if (leftOver != 0) length++; + + data = new uint [length]; + + for (int i = inData.Length - 1, j = 0; i >= 3; i -= 4, j++) { + data [j] = (uint)( + (inData [i-3] << (3*8)) | + (inData [i-2] << (2*8)) | + (inData [i-1] << (1*8)) | + (inData [i-0] << (0*8)) + ); + } + + switch (leftOver) { + case 1: data [length-1] = (uint)inData [0]; break; + case 2: data [length-1] = (uint)((inData [0] << 8) | inData [1]); break; + case 3: data [length-1] = (uint)((inData [0] << 16) | (inData [1] << 8) | inData [2]); break; + } + + this.Normalize (); + } + + public BigInteger (uint [] inData) + { + length = (uint)inData.Length; + + data = new uint [length]; + + for (int i = (int)length - 1, j = 0; i >= 0; i--, j++) + data [j] = inData [i]; + + this.Normalize (); + } + + public BigInteger (uint ui) + { + data = new uint [] {ui}; + } + + public BigInteger (ulong ul) + { + data = new uint [2] { (uint)ul, (uint)(ul >> 32)}; + length = 2; + + this.Normalize (); + } + + public static implicit operator BigInteger (uint value) + { + return (new BigInteger (value)); + } + + public static implicit operator BigInteger (int value) + { + if (value < 0) throw new ArgumentOutOfRangeException ("value"); + return (new BigInteger ((uint)value)); + } + + public static implicit operator BigInteger (ulong value) + { + return (new BigInteger (value)); + } + + #endregion + + #region Operators + + public static BigInteger operator + (BigInteger bi1, BigInteger bi2) + { + if (bi1 == 0) + return new BigInteger (bi2); + else if (bi2 == 0) + return new BigInteger (bi1); + else + return Kernel.AddSameSign (bi1, bi2); + } + + public static BigInteger operator - (BigInteger bi1, BigInteger bi2) + { + if (bi2 == 0) + return new BigInteger (bi1); + + if (bi1 == 0) + throw new ArithmeticException (WouldReturnNegVal); + + switch (Kernel.Compare (bi1, bi2)) { + + case Sign.Zero: + return 0; + + case Sign.Positive: + return Kernel.Subtract (bi1, bi2); + + case Sign.Negative: + throw new ArithmeticException (WouldReturnNegVal); + default: + throw new InvalidOperationException (); + } + } + + public static int operator % (BigInteger bi, int i) + { + if (i > 0) + return (int)Kernel.DwordMod (bi, (uint)i); + else + return -(int)Kernel.DwordMod (bi, (uint)-i); + } + + public static uint operator % (BigInteger bi, uint ui) + { + return Kernel.DwordMod (bi, (uint)ui); + } + + public static BigInteger operator % (BigInteger bi1, BigInteger bi2) + { + return Kernel.multiByteDivide (bi1, bi2)[1]; + } + + public static BigInteger operator / (BigInteger bi, int i) + { + if (i > 0) + return Kernel.DwordDiv (bi, (uint)i); + + throw new ArithmeticException (WouldReturnNegVal); + } + + public static BigInteger operator / (BigInteger bi1, BigInteger bi2) + { + return Kernel.multiByteDivide (bi1, bi2)[0]; + } + + public static BigInteger operator * (BigInteger bi1, BigInteger bi2) + { + if (bi1 == 0 || bi2 == 0) return 0; + + // + // Validate pointers + // + if (bi1.data.Length < bi1.length) throw new IndexOutOfRangeException ("bi1 out of range"); + if (bi2.data.Length < bi2.length) throw new IndexOutOfRangeException ("bi2 out of range"); + + BigInteger ret = new BigInteger (Sign.Positive, bi1.length + bi2.length); + + Kernel.Multiply (bi1.data, 0, bi1.length, bi2.data, 0, bi2.length, ret.data, 0); + + ret.Normalize (); + return ret; + } + + public static BigInteger operator * (BigInteger bi, int i) + { + if (i < 0) throw new ArithmeticException (WouldReturnNegVal); + if (i == 0) return 0; + if (i == 1) return new BigInteger (bi); + + return Kernel.MultiplyByDword (bi, (uint)i); + } + + public static BigInteger operator << (BigInteger bi1, int shiftVal) + { + return Kernel.LeftShift (bi1, shiftVal); + } + + public static BigInteger operator >> (BigInteger bi1, int shiftVal) + { + return Kernel.RightShift (bi1, shiftVal); + } + + #endregion + + #region Random + private static RandomNumberGenerator rng; + private static RandomNumberGenerator Rng { + get { + if (rng == null) + rng = RandomNumberGenerator.Create (); + return rng; + } + } + + /// <summary> + /// Generates a new, random BigInteger of the specified length. + /// </summary> + /// <param name="bits">The number of bits for the new number.</param> + /// <param name="rng">A random number generator to use to obtain the bits.</param> + /// <returns>A random number of the specified length.</returns> + public static BigInteger genRandom (int bits, RandomNumberGenerator rng) + { + int dwords = bits >> 5; + int remBits = bits & 0x1F; + + if (remBits != 0) + dwords++; + + BigInteger ret = new BigInteger (Sign.Positive, (uint)dwords + 1); + byte [] random = new byte [dwords << 2]; + + rng.GetBytes (random); + Buffer.BlockCopy (random, 0, ret.data, 0, (int)dwords << 2); + + if (remBits != 0) { + uint mask = (uint)(0x01 << (remBits-1)); + ret.data [dwords-1] |= mask; + + mask = (uint)(0xFFFFFFFF >> (32 - remBits)); + ret.data [dwords-1] &= mask; + } + else + ret.data [dwords-1] |= 0x80000000; + + ret.Normalize (); + return ret; + } + + /// <summary> + /// Generates a new, random BigInteger of the specified length using the default RNG crypto service provider. + /// </summary> + /// <param name="bits">The number of bits for the new number.</param> + /// <returns>A random number of the specified length.</returns> + public static BigInteger genRandom (int bits) + { + return genRandom (bits, Rng); + } + + /// <summary> + /// Randomizes the bits in "this" from the specified RNG. + /// </summary> + /// <param name="rng">A RNG.</param> + public void randomize (RandomNumberGenerator rng) + { + int bits = this.bitCount (); + int dwords = bits >> 5; + int remBits = bits & 0x1F; + + if (remBits != 0) + dwords++; + + byte [] random = new byte [dwords << 2]; + + rng.GetBytes (random); + Buffer.BlockCopy (random, 0, data, 0, (int)dwords << 2); + + if (remBits != 0) { + uint mask = (uint)(0x01 << (remBits-1)); + data [dwords-1] |= mask; + + mask = (uint)(0xFFFFFFFF >> (32 - remBits)); + data [dwords-1] &= mask; + } + + else + data [dwords-1] |= 0x80000000; + + Normalize (); + } + + /// <summary> + /// Randomizes the bits in "this" from the default RNG. + /// </summary> + public void randomize () + { + randomize (Rng); + } + + #endregion + + #region Bitwise + + public int bitCount () + { + this.Normalize (); + + uint value = data [length - 1]; + uint mask = 0x80000000; + uint bits = 32; + + while (bits > 0 && (value & mask) == 0) { + bits--; + mask >>= 1; + } + bits += ((length - 1) << 5); + + return (int)bits; + } + + /// <summary> + /// Tests if the specified bit is 1. + /// </summary> + /// <param name="bitNum">The bit to test. The least significant bit is 0.</param> + /// <returns>True if bitNum is set to 1, else false.</returns> + public bool testBit (uint bitNum) + { + uint bytePos = bitNum >> 5; // divide by 32 + byte bitPos = (byte)(bitNum & 0x1F); // get the lowest 5 bits + + uint mask = (uint)1 << bitPos; + return ((this.data [bytePos] & mask) != 0); + } + + public bool testBit (int bitNum) + { + if (bitNum < 0) throw new ArgumentOutOfRangeException ("bitNum"); + + uint bytePos = (uint)bitNum >> 5; // divide by 32 + byte bitPos = (byte)(bitNum & 0x1F); // get the lowest 5 bits + + uint mask = (uint)1 << bitPos; + return ((this.data [bytePos] | mask) == this.data [bytePos]); + } + + public void setBit (uint bitNum) + { + setBit (bitNum, true); + } + public void clearBit (uint bitNum) + { + setBit (bitNum, false); + } + + public void setBit (uint bitNum, bool val) + { + uint bytePos = bitNum >> 5; // divide by 32 + + if (bytePos < this.length) { + uint mask = (uint)1 << (int)(bitNum & 0x1F); + if (val) + this.data [bytePos] |= mask; + else + this.data [bytePos] &= ~mask; + } + } + + public int LowestSetBit () + { + if (this == 0) return -1; + int i = 0; + while (!testBit (i)) i++; + return i; + } + + public byte [] getBytes () + { + if (this == 0) return new byte [1]; + + int numBits = bitCount (); + int numBytes = numBits >> 3; + if ((numBits & 0x7) != 0) + numBytes++; + + byte [] result = new byte [numBytes]; + + int numBytesInWord = numBytes & 0x3; + if (numBytesInWord == 0) numBytesInWord = 4; + + int pos = 0; + for (int i = (int)length - 1; i >= 0; i--) { + uint val = data [i]; + for (int j = numBytesInWord - 1; j >= 0; j--) { + result [pos+j] = (byte)(val & 0xFF); + val >>= 8; + } + pos += numBytesInWord; + numBytesInWord = 4; + } + return result; + } + + #endregion + + #region Compare + + public static bool operator == (BigInteger bi1, uint ui) + { + if (bi1.length != 1) bi1.Normalize (); + return bi1.length == 1 && bi1.data [0] == ui; + } + + public static bool operator != (BigInteger bi1, uint ui) + { + if (bi1.length != 1) bi1.Normalize (); + return !(bi1.length == 1 && bi1.data [0] == ui); + } + + public static bool operator == (BigInteger bi1, BigInteger bi2) + { + // we need to compare with null + if ((bi1 as object) == (bi2 as object)) + return true; + if (null == bi1 || null == bi2) + return false; + return Kernel.Compare (bi1, bi2) == 0; + } + + public static bool operator != (BigInteger bi1, BigInteger bi2) + { + // we need to compare with null + if ((bi1 as object) == (bi2 as object)) + return false; + if (null == bi1 || null == bi2) + return true; + return Kernel.Compare (bi1, bi2) != 0; + } + + public static bool operator > (BigInteger bi1, BigInteger bi2) + { + return Kernel.Compare (bi1, bi2) > 0; + } + + public static bool operator < (BigInteger bi1, BigInteger bi2) + { + return Kernel.Compare (bi1, bi2) < 0; + } + + public static bool operator >= (BigInteger bi1, BigInteger bi2) + { + return Kernel.Compare (bi1, bi2) >= 0; + } + + public static bool operator <= (BigInteger bi1, BigInteger bi2) + { + return Kernel.Compare (bi1, bi2) <= 0; + } + + public Sign Compare (BigInteger bi) + { + return Kernel.Compare (this, bi); + } + + #endregion + + #region Formatting + + public string ToString (uint radix) + { + return ToString (radix, "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"); + } + + public string ToString (uint radix, string charSet) + { + if (charSet.Length < radix) + throw new ArgumentException ("charSet length less than radix", "charSet"); + if (radix == 1) + throw new ArgumentException ("There is no such thing as radix one notation", "radix"); + + if (this == 0) return "0"; + if (this == 1) return "1"; + + string result = ""; + + BigInteger a = new BigInteger (this); + + while (a != 0) { + uint rem = Kernel.SingleByteDivideInPlace (a, radix); + result = charSet [ (int)rem] + result; + } + + return result; + } + + #endregion + + #region Misc + + /// <summary> + /// Normalizes this by setting the length to the actual number of + /// uints used in data and by setting the sign to Sign.Zero if the + /// value of this is 0. + /// </summary> + private void Normalize () + { + // Normalize length + while (length > 0 && data [length-1] == 0) length--; + + // Check for zero + if (length == 0) + length++; + } + + public void Clear () + { + for (int i=0; i < length; i++) + data [i] = 0x00; + } + + #endregion + + #region Object Impl + + public override int GetHashCode () + { + uint val = 0; + + for (uint i = 0; i < this.length; i++) + val ^= this.data [i]; + + return (int)val; + } + + public override string ToString () + { + return ToString (10); + } + + public override bool Equals (object o) + { + if (o == null) return false; + if (o is int) return (int)o >= 0 && this == (uint)o; + + return Kernel.Compare (this, (BigInteger)o) == 0; + } + + #endregion + + #region Number Theory + + public BigInteger gcd (BigInteger bi) + { + return Kernel.gcd (this, bi); + } + + public BigInteger modInverse (BigInteger mod) + { + return Kernel.modInverse (this, mod); + } + + public BigInteger modPow (BigInteger exp, BigInteger n) + { + ModulusRing mr = new ModulusRing (n); + return mr.Pow (this, exp); + } + + #endregion + + #region Prime Testing + + public bool isProbablePrime () + { + + for (int p = 0; p < smallPrimes.Length; p++) { + if (this == smallPrimes [p]) + return true; + if (this % smallPrimes [p] == 0) + return false; + } + + return PrimalityTests.RabinMillerTest (this, Prime.ConfidenceFactor.Medium); + } + + [Obsolete] + public bool isProbablePrime (int notUsed) + { + + for (int p = 0; p < smallPrimes.Length; p++) { + if (this % smallPrimes [p] == 0) + return false; + } + + return + PrimalityTests.SmallPrimeSppTest (this, Prime.ConfidenceFactor.Medium); + } + + #endregion + + #region Prime Number Generation + + /// <summary> + /// Generates the smallest prime >= bi + /// </summary> + /// <param name="bi">A BigInteger</param> + /// <returns>The smallest prime >= bi. More mathematically, if bi is prime: bi, else Prime [PrimePi [bi] + 1].</returns> + public static BigInteger NextHightestPrime (BigInteger bi) + { + NextPrimeFinder npf = new NextPrimeFinder (); + return npf.GenerateNewPrime (0, bi); + } + + public static BigInteger genPseudoPrime (int bits) + { + SequentialSearchPrimeGeneratorBase sspg = new SequentialSearchPrimeGeneratorBase (); + return sspg.GenerateNewPrime (bits); + } + + /// <summary> + /// Increments this by two + /// </summary> + public void Incr2 () + { + int i = 0; + + data [0] += 2; + + // If there was no carry, nothing to do + if (data [0] < 2) { + + // Account for the first carry + data [++i]++; + + // Keep adding until no carry + while (data [i++] == 0x0) + data [i]++; + + // See if we increased the data length + if (length == (uint)i) + length++; + } + } + + #endregion + + public sealed class ModulusRing { + + BigInteger mod, constant; + + public ModulusRing (BigInteger mod) + { + this.mod = mod; + + // calculate constant = b^ (2k) / m + uint i = mod.length << 1; + + constant = new BigInteger (Sign.Positive, i + 1); + constant.data [i] = 0x00000001; + + constant = constant / mod; + } + + public void BarrettReduction (BigInteger x) + { + BigInteger n = mod; + uint k = n.length, + kPlusOne = k+1, + kMinusOne = k-1; + + // x < mod, so nothing to do. + if (x.length < k) return; + + BigInteger q3; + + // + // Validate pointers + // + if (x.data.Length < x.length) throw new IndexOutOfRangeException ("x out of range"); + + // q1 = x / b^ (k-1) + // q2 = q1 * constant + // q3 = q2 / b^ (k+1), Needs to be accessed with an offset of kPlusOne + + // TODO: We should the method in HAC p 604 to do this (14.45) + q3 = new BigInteger (Sign.Positive, x.length - kMinusOne + constant.length); + Kernel.Multiply (x.data, kMinusOne, x.length - kMinusOne, constant.data, 0, constant.length, q3.data, 0); + + // r1 = x mod b^ (k+1) + // i.e. keep the lowest (k+1) words + + uint lengthToCopy = (x.length > kPlusOne) ? kPlusOne : x.length; + + x.length = lengthToCopy; + x.Normalize (); + + // r2 = (q3 * n) mod b^ (k+1) + // partial multiplication of q3 and n + + BigInteger r2 = new BigInteger (Sign.Positive, kPlusOne); + Kernel.MultiplyMod2p32pmod (q3.data, (int)kPlusOne, (int)q3.length - (int)kPlusOne, n.data, 0, (int)n.length, r2.data, 0, (int)kPlusOne); + + r2.Normalize (); + + if (r2 < x) { + Kernel.MinusEq (x, r2); + } else { + BigInteger val = new BigInteger (Sign.Positive, kPlusOne + 1); + val.data [kPlusOne] = 0x00000001; + + Kernel.MinusEq (val, r2); + Kernel.PlusEq (x, val); + } + + while (x >= n) + Kernel.MinusEq (x, n); + } + + public BigInteger Multiply (BigInteger a, BigInteger b) + { + if (a == 0 || b == 0) return 0; + + if (a.length >= mod.length << 1) + a %= mod; + + if (b.length >= mod.length << 1) + b %= mod; + + if (a.length >= mod.length) + BarrettReduction (a); + + if (b.length >= mod.length) + BarrettReduction (b); + + BigInteger ret = new BigInteger (a * b); + BarrettReduction (ret); + + return ret; + } + + public BigInteger Difference (BigInteger a, BigInteger b) + { + Sign cmp = Kernel.Compare (a, b); + BigInteger diff; + + switch (cmp) { + case Sign.Zero: + return 0; + case Sign.Positive: + diff = a - b; break; + case Sign.Negative: + diff = b - a; break; + default: + throw new InvalidOperationException(); + } + + if (diff >= mod) { + if (diff.length >= mod.length << 1) + diff %= mod; + else + BarrettReduction (diff); + } + if (cmp == Sign.Negative) + diff = mod - diff; + return diff; + } + + public BigInteger Pow (BigInteger b, BigInteger exp) + { + if ((mod.data [0] & 1) == 1) return OddPow (b, exp); + else return EvenPow (b, exp); + } + + public BigInteger EvenPow (BigInteger b, BigInteger exp) + { + BigInteger resultNum = new BigInteger ((BigInteger)1, mod.length << 1); + BigInteger tempNum = new BigInteger (b % mod, mod.length << 1); // ensures (tempNum * tempNum) < b^ (2k) + + uint totalBits = (uint)exp.bitCount (); + + uint [] wkspace = new uint [mod.length << 1]; + + // perform squaring and multiply exponentiation + for (uint pos = 0; pos < totalBits; pos++) { + if (exp.testBit (pos)) { + + Array.Clear (wkspace, 0, wkspace.Length); + Kernel.Multiply (resultNum.data, 0, resultNum.length, tempNum.data, 0, tempNum.length, wkspace, 0); + resultNum.length += tempNum.length; + uint [] t = wkspace; + wkspace = resultNum.data; + resultNum.data = t; + + BarrettReduction (resultNum); + } + + Kernel.SquarePositive (tempNum, ref wkspace); + BarrettReduction (tempNum); + + if (tempNum == 1) { + return resultNum; + } + } + + return resultNum; + } + + private BigInteger OddPow (BigInteger b, BigInteger exp) + { + BigInteger resultNum = new BigInteger (Montgomery.ToMont (1, mod), mod.length << 1); + BigInteger tempNum = new BigInteger (Montgomery.ToMont (b, mod), mod.length << 1); // ensures (tempNum * tempNum) < b^ (2k) + uint mPrime = Montgomery.Inverse (mod.data [0]); + uint totalBits = (uint)exp.bitCount (); + + uint [] wkspace = new uint [mod.length << 1]; + + // perform squaring and multiply exponentiation + for (uint pos = 0; pos < totalBits; pos++) { + if (exp.testBit (pos)) { + + Array.Clear (wkspace, 0, wkspace.Length); + Kernel.Multiply (resultNum.data, 0, resultNum.length, tempNum.data, 0, tempNum.length, wkspace, 0); + resultNum.length += tempNum.length; + uint [] t = wkspace; + wkspace = resultNum.data; + resultNum.data = t; + + Montgomery.Reduce (resultNum, mod, mPrime); + } + + Kernel.SquarePositive (tempNum, ref wkspace); + Montgomery.Reduce (tempNum, mod, mPrime); + } + + Montgomery.Reduce (resultNum, mod, mPrime); + return resultNum; + } + + #region Pow Small Base + + // TODO: Make tests for this, not really needed b/c prime stuff + // checks it, but still would be nice + public BigInteger Pow (uint b, BigInteger exp) + { + if (b != 2) { + if ((mod.data [0] & 1) == 1) return OddPow (b, exp); + else return EvenPow (b, exp); + } else { + if ((mod.data [0] & 1) == 1) return OddModTwoPow (exp); + else return EvenModTwoPow (exp); + } + } + + private BigInteger OddPow (uint b, BigInteger exp) + { + exp.Normalize (); + uint [] wkspace = new uint [mod.length << 1 + 1]; + + BigInteger resultNum = Montgomery.ToMont ((BigInteger)b, this.mod); + resultNum = new BigInteger (resultNum, mod.length << 1 +1); + + uint mPrime = Montgomery.Inverse (mod.data [0]); + + uint pos = (uint)exp.bitCount () - 2; + + // + // We know that the first itr will make the val b + // + + do { + // + // r = r ^ 2 % m + // + Kernel.SquarePositive(resultNum, ref wkspace); + resultNum = Montgomery.Reduce(resultNum, mod, mPrime); + + if (exp.testBit(pos)) { + + // + // r = r * b % m + // + + uint u = 0; + + uint i = 0; + ulong mc = 0; + + do { + mc += (ulong)resultNum.data[u + i] * (ulong)b; + resultNum.data[u + i] = (uint)mc; + mc >>= 32; + } while (++i < resultNum.length); + + if (resultNum.length < mod.length) { + if (mc != 0) { + resultNum.data[u + i] = (uint)mc; + resultNum.length++; + while (resultNum >= mod) + Kernel.MinusEq(resultNum, mod); + } + } else if (mc != 0) { + + // + // First, we estimate the quotient by dividing + // the first part of each of the numbers. Then + // we correct this, if necessary, with a subtraction. + // + + uint cc = (uint)mc; + + // We would rather have this estimate overshoot, + // so we add one to the divisor + uint divEstimate = (uint)((((ulong)cc << 32) | (ulong)resultNum.data[u + i - 1]) / + (mod.data[mod.length - 1] + 1)); + + uint t; + + i = 0; + mc = 0; + do { + mc += (ulong)mod.data[i] * (ulong)divEstimate; + t = resultNum.data[u + i]; + resultNum.data[u + i] -= (uint)mc; + mc >>= 32; + if (resultNum.data[u + i] > t) mc++; + i++; + } while (i < resultNum.length); + cc -= (uint)mc; + + if (cc != 0) { + + uint sc = 0, j = 0; + uint[] s = mod.data; + do { + uint a = s[j]; + if (((a += sc) < sc) | ((resultNum.data[u + j] -= a) > ~a)) sc = 1; + else sc = 0; + j++; + } while (j < resultNum.length); + cc -= sc; + } + while (resultNum >= mod) + Kernel.MinusEq(resultNum, mod); + } else { + while (resultNum >= mod) + Kernel.MinusEq(resultNum, mod); + } + } + } while (pos-- > 0); + + resultNum = Montgomery.Reduce (resultNum, mod, mPrime); + return resultNum; + + } + + private BigInteger EvenPow(uint b, BigInteger exp) { + exp.Normalize(); + uint[] wkspace = new uint[mod.length << 1 + 1]; + BigInteger resultNum = new BigInteger((BigInteger)b, mod.length << 1 + 1); + + uint pos = (uint)exp.bitCount() - 2; + + // + // We know that the first itr will make the val b + // + + do { + // + // r = r ^ 2 % m + // + Kernel.SquarePositive(resultNum, ref wkspace); + if (!(resultNum.length < mod.length)) + BarrettReduction(resultNum); + + if (exp.testBit(pos)) { + + // + // r = r * b % m + // + + uint u = 0; + + uint i = 0; + ulong mc = 0; + + do { + mc += (ulong)resultNum.data[u + i] * (ulong)b; + resultNum.data[u + i] = (uint)mc; + mc >>= 32; + } while (++i < resultNum.length); + + if (resultNum.length < mod.length) { + if (mc != 0) { + resultNum.data[u + i] = (uint)mc; + resultNum.length++; + while (resultNum >= mod) + Kernel.MinusEq(resultNum, mod); + } + } else if (mc != 0) { + + // + // First, we estimate the quotient by dividing + // the first part of each of the numbers. Then + // we correct this, if necessary, with a subtraction. + // + + uint cc = (uint)mc; + + // We would rather have this estimate overshoot, + // so we add one to the divisor + uint divEstimate = (uint)((((ulong)cc << 32) | (ulong)resultNum.data[u + i - 1]) / + (mod.data[mod.length - 1] + 1)); + + uint t; + + i = 0; + mc = 0; + do { + mc += (ulong)mod.data[i] * (ulong)divEstimate; + t = resultNum.data[u + i]; + resultNum.data[u + i] -= (uint)mc; + mc >>= 32; + if (resultNum.data[u + i] > t) mc++; + i++; + } while (i < resultNum.length); + cc -= (uint)mc; + + if (cc != 0) { + + uint sc = 0, j = 0; + uint[] s = mod.data; + do { + uint a = s[j]; + if (((a += sc) < sc) | ((resultNum.data[u + j] -= a) > ~a)) sc = 1; + else sc = 0; + j++; + } while (j < resultNum.length); + cc -= sc; + } + while (resultNum >= mod) + Kernel.MinusEq(resultNum, mod); + } else { + while (resultNum >= mod) + Kernel.MinusEq(resultNum, mod); + } + } + } while (pos-- > 0); + + return resultNum; + } + + private BigInteger EvenModTwoPow (BigInteger exp) + { + exp.Normalize (); + uint [] wkspace = new uint [mod.length << 1 + 1]; + + BigInteger resultNum = new BigInteger (2, mod.length << 1 +1); + + uint value = exp.data [exp.length - 1]; + uint mask = 0x80000000; + + // Find the first bit of the exponent + while ((value & mask) == 0) + mask >>= 1; + + // + // We know that the first itr will make the val 2, + // so eat one bit of the exponent + // + mask >>= 1; + + uint wPos = exp.length - 1; + + do { + value = exp.data [wPos]; + do { + Kernel.SquarePositive (resultNum, ref wkspace); + if (resultNum.length >= mod.length) + BarrettReduction (resultNum); + + if ((value & mask) != 0) { + // + // resultNum = (resultNum * 2) % mod + // + + uint u = 0; + // + // Double + // + uint uu = u; + uint uuE = u + resultNum.length; + uint x, carry = 0; + while (uu < uuE) { + x = resultNum.data[uu]; + resultNum.data[uu] = (x << 1) | carry; + carry = x >> (32 - 1); + uu++; + } + + // subtraction inlined because we know it is square + if (carry != 0 || resultNum >= mod) { + uu = u; + uint c = 0; + uint[] s = mod.data; + uint i = 0; + do { + uint a = s[i]; + if (((a += c) < c) | ((resultNum.data[uu++] -= a) > ~a)) + c = 1; + else + c = 0; + i++; + } while (uu < uuE); + } + + } + } while ((mask >>= 1) > 0); + mask = 0x80000000; + } while (wPos-- > 0); + + return resultNum; + } + + private BigInteger OddModTwoPow (BigInteger exp) + { + + uint [] wkspace = new uint [mod.length << 1 + 1]; + + BigInteger resultNum = Montgomery.ToMont ((BigInteger)2, this.mod); + resultNum = new BigInteger (resultNum, mod.length << 1 +1); + + uint mPrime = Montgomery.Inverse (mod.data [0]); + + // + // TODO: eat small bits, the ones we can do with no modular reduction + // + uint pos = (uint)exp.bitCount () - 2; + + do { + Kernel.SquarePositive (resultNum, ref wkspace); + resultNum = Montgomery.Reduce (resultNum, mod, mPrime); + + if (exp.testBit(pos)) { + // + // resultNum = (resultNum * 2) % mod + // + + uint u = 0; + // + // Double + // + uint uu = u; + uint uuE = u + resultNum.length; + uint x, carry = 0; + while (uu < uuE) { + x = resultNum.data[uu]; + resultNum.data[uu] = (x << 1) | carry; + carry = x >> (32 - 1); + uu++; + } + + // subtraction inlined because we know it is square + if (carry != 0 || resultNum >= mod) { + uint s = 0; + uu = u; + uint c = 0; + uint ss = s; + do { + uint a = mod.data[ss++]; + if (((a += c) < c) | ((resultNum.data[uu++] -= a) > ~a)) + c = 1; + else + c = 0; + } while (uu < uuE); + } + } + } while (pos-- > 0); + + resultNum = Montgomery.Reduce (resultNum, mod, mPrime); + return resultNum; + } + + #endregion + } + + public sealed class Montgomery { + public static uint Inverse (uint n) + { + uint y = n, z; + + while ((z = n * y) != 1) + y *= 2 - z; + + return (uint)-y; + } + + public static BigInteger ToMont (BigInteger n, BigInteger m) + { + n.Normalize (); m.Normalize (); + + n <<= (int)m.length * 32; + n %= m; + return n; + } + + public static BigInteger Reduce(BigInteger n, BigInteger m, uint mPrime) + { + BigInteger A = n; + uint a = 0, mm = 0; + for (uint i = 0; i < m.length; i++) { + // The mod here is taken care of by the CPU, + // since the multiply will overflow. + uint u_i = A.data[a] * mPrime /* % 2^32 */; + + // + // A += u_i * m; + // A >>= 32 + // + + // mP = Position in mod + // aSP = the source of bits from a + // aDP = destination for bits + uint mP = mm, aSP = a, aDP = a; + + ulong c = (ulong)u_i * (ulong)m.data[mP++] + A.data[aSP++]; + c >>= 32; + uint j = 1; + + // Multiply and add + for (; j < m.length; j++) { + c += (ulong)u_i * (ulong)m.data[mP++] + A.data[aSP++]; + A.data[aDP++] = (uint)c; + c >>= 32; + } + + // Account for carry + // TODO: use a better loop here, we dont need the ulong stuff + for (; j < A.length; j++) { + c += A.data[aSP++]; + A.data[aDP++] = (uint)c; + c >>= 32; + if (c == 0) { j++; break; } + } + // Copy the rest + for (; j < A.length; j++) { + A.data[aDP++] = A.data[aSP++]; + } + + A.data[aDP++] = (uint)c; + } + + while (A.length > 1 && A.data[a + A.length - 1] == 0) A.length--; + + if (A >= m) Kernel.MinusEq(A, m); + + return A; + } + + public static BigInteger Reduce (BigInteger n, BigInteger m) + { + return Reduce (n, m, Inverse (m.data [0])); + } + } + + /// <summary> + /// Low level functions for the BigInteger + /// </summary> + private sealed class Kernel { + private Kernel() { } + #region Addition/Subtraction + + /// <summary> + /// Adds two numbers with the same sign. + /// </summary> + /// <param name="bi1">A BigInteger</param> + /// <param name="bi2">A BigInteger</param> + /// <returns>bi1 + bi2</returns> + public static BigInteger AddSameSign (BigInteger bi1, BigInteger bi2) + { + uint [] x, y; + uint yMax, xMax, i = 0; + + // x should be bigger + if (bi1.length < bi2.length) { + x = bi2.data; + xMax = bi2.length; + y = bi1.data; + yMax = bi1.length; + } else { + x = bi1.data; + xMax = bi1.length; + y = bi2.data; + yMax = bi2.length; + } + + BigInteger result = new BigInteger (Sign.Positive, xMax + 1); + + uint [] r = result.data; + + ulong sum = 0; + + // Add common parts of both numbers + do { + sum = ((ulong)x [i]) + ((ulong)y [i]) + sum; + r [i] = (uint)sum; + sum >>= 32; + } while (++i < yMax); + + // Copy remainder of longer number while carry propagation is required + bool carry = (sum != 0); + + if (carry) { + + if (i < xMax) { + do + carry = ((r [i] = x [i] + 1) == 0); + while (++i < xMax && carry); + } + + if (carry) { + r [i] = 1; + result.length = ++i; + return result; + } + } + + // Copy the rest + if (i < xMax) { + do + r [i] = x [i]; + while (++i < xMax); + } + + result.Normalize (); + return result; + } + + public static BigInteger Subtract (BigInteger big, BigInteger small) + { + BigInteger result = new BigInteger (Sign.Positive, big.length); + + uint [] r = result.data, b = big.data, s = small.data; + uint i = 0, c = 0; + + do { + + uint x = s [i]; + if (((x += c) < c) | ((r [i] = b [i] - x) > ~x)) + c = 1; + else + c = 0; + + } while (++i < small.length); + + if (i == big.length) goto fixup; + + if (c == 1) { + do + r [i] = b [i] - 1; + while (b [i++] == 0 && i < big.length); + + if (i == big.length) goto fixup; + } + + do + r [i] = b [i]; + while (++i < big.length); + + fixup: + + result.Normalize (); + return result; + } + + public static void MinusEq (BigInteger big, BigInteger small) + { + uint [] b = big.data, s = small.data; + uint i = 0, c = 0; + + do { + uint x = s [i]; + if (((x += c) < c) | ((b [i] -= x) > ~x)) + c = 1; + else + c = 0; + } while (++i < small.length); + + if (i == big.length) goto fixup; + + if (c == 1) { + do + b [i]--; + while (b [i++] == 0 && i < big.length); + } + + fixup: + + // Normalize length + while (big.length > 0 && big.data [big.length-1] == 0) big.length--; + + // Check for zero + if (big.length == 0) + big.length++; + + } + + public static void PlusEq (BigInteger bi1, BigInteger bi2) + { + uint [] x, y; + uint yMax, xMax, i = 0; + bool flag = false; + + // x should be bigger + if (bi1.length < bi2.length){ + flag = true; + x = bi2.data; + xMax = bi2.length; + y = bi1.data; + yMax = bi1.length; + } else { + x = bi1.data; + xMax = bi1.length; + y = bi2.data; + yMax = bi2.length; + } + + uint [] r = bi1.data; + + ulong sum = 0; + + // Add common parts of both numbers + do { + sum += ((ulong)x [i]) + ((ulong)y [i]); + r [i] = (uint)sum; + sum >>= 32; + } while (++i < yMax); + + // Copy remainder of longer number while carry propagation is required + bool carry = (sum != 0); + + if (carry){ + + if (i < xMax) { + do + carry = ((r [i] = x [i] + 1) == 0); + while (++i < xMax && carry); + } + + if (carry) { + r [i] = 1; + bi1.length = ++i; + return; + } + } + + // Copy the rest + if (flag && i < xMax - 1) { + do + r [i] = x [i]; + while (++i < xMax); + } + + bi1.length = xMax + 1; + bi1.Normalize (); + } + + #endregion + + #region Compare + + /// <summary> + /// Compares two BigInteger + /// </summary> + /// <param name="bi1">A BigInteger</param> + /// <param name="bi2">A BigInteger</param> + /// <returns>The sign of bi1 - bi2</returns> + public static Sign Compare (BigInteger bi1, BigInteger bi2) + { + // + // Step 1. Compare the lengths + // + uint l1 = bi1.length, l2 = bi2.length; + + while (l1 > 0 && bi1.data [l1-1] == 0) l1--; + while (l2 > 0 && bi2.data [l2-1] == 0) l2--; + + if (l1 == 0 && l2 == 0) return Sign.Zero; + + // bi1 len < bi2 len + if (l1 < l2) return Sign.Negative; + // bi1 len > bi2 len + else if (l1 > l2) return Sign.Positive; + + // + // Step 2. Compare the bits + // + + uint pos = l1 - 1; + + while (pos != 0 && bi1.data [pos] == bi2.data [pos]) pos--; + + if (bi1.data [pos] < bi2.data [pos]) + return Sign.Negative; + else if (bi1.data [pos] > bi2.data [pos]) + return Sign.Positive; + else + return Sign.Zero; + } + + #endregion + + #region Division + + #region Dword + + /// <summary> + /// Performs n / d and n % d in one operation. + /// </summary> + /// <param name="n">A BigInteger, upon exit this will hold n / d</param> + /// <param name="d">The divisor</param> + /// <returns>n % d</returns> + public static uint SingleByteDivideInPlace (BigInteger n, uint d) + { + ulong r = 0; + uint i = n.length; + + while (i-- > 0) { + r <<= 32; + r |= n.data [i]; + n.data [i] = (uint)(r / d); + r %= d; + } + n.Normalize (); + + return (uint)r; + } + + public static uint DwordMod (BigInteger n, uint d) + { + ulong r = 0; + uint i = n.length; + + while (i-- > 0) { + r <<= 32; + r |= n.data [i]; + r %= d; + } + + return (uint)r; + } + + public static BigInteger DwordDiv (BigInteger n, uint d) + { + BigInteger ret = new BigInteger (Sign.Positive, n.length); + + ulong r = 0; + uint i = n.length; + + while (i-- > 0) { + r <<= 32; + r |= n.data [i]; + ret.data [i] = (uint)(r / d); + r %= d; + } + ret.Normalize (); + + return ret; + } + + public static BigInteger [] DwordDivMod (BigInteger n, uint d) + { + BigInteger ret = new BigInteger (Sign.Positive , n.length); + + ulong r = 0; + uint i = n.length; + + while (i-- > 0) { + r <<= 32; + r |= n.data [i]; + ret.data [i] = (uint)(r / d); + r %= d; + } + ret.Normalize (); + + BigInteger rem = (uint)r; + + return new BigInteger [] {ret, rem}; + } + + #endregion + + #region BigNum + + public static BigInteger [] multiByteDivide (BigInteger bi1, BigInteger bi2) + { + if (Kernel.Compare (bi1, bi2) == Sign.Negative) + return new BigInteger [2] { 0, new BigInteger (bi1) }; + + bi1.Normalize (); bi2.Normalize (); + + if (bi2.length == 1) + return DwordDivMod (bi1, bi2.data [0]); + + uint remainderLen = bi1.length + 1; + int divisorLen = (int)bi2.length + 1; + + uint mask = 0x80000000; + uint val = bi2.data [bi2.length - 1]; + int shift = 0; + int resultPos = (int)bi1.length - (int)bi2.length; + + while (mask != 0 && (val & mask) == 0) { + shift++; mask >>= 1; + } + + BigInteger quot = new BigInteger (Sign.Positive, bi1.length - bi2.length + 1); + BigInteger rem = (bi1 << shift); + + uint [] remainder = rem.data; + + bi2 = bi2 << shift; + + int j = (int)(remainderLen - bi2.length); + int pos = (int)remainderLen - 1; + + uint firstDivisorByte = bi2.data [bi2.length-1]; + ulong secondDivisorByte = bi2.data [bi2.length-2]; + + while (j > 0) { + ulong dividend = ((ulong)remainder [pos] << 32) + (ulong)remainder [pos-1]; + + ulong q_hat = dividend / (ulong)firstDivisorByte; + ulong r_hat = dividend % (ulong)firstDivisorByte; + + do { + + if (q_hat == 0x100000000 || + (q_hat * secondDivisorByte) > ((r_hat << 32) + remainder [pos-2])) { + q_hat--; + r_hat += (ulong)firstDivisorByte; + + if (r_hat < 0x100000000) + continue; + } + break; + } while (true); + + // + // At this point, q_hat is either exact, or one too large + // (more likely to be exact) so, we attempt to multiply the + // divisor by q_hat, if we get a borrow, we just subtract + // one from q_hat and add the divisor back. + // + + uint t; + uint dPos = 0; + int nPos = pos - divisorLen + 1; + ulong mc = 0; + uint uint_q_hat = (uint)q_hat; + do { + mc += (ulong)bi2.data [dPos] * (ulong)uint_q_hat; + t = remainder [nPos]; + remainder [nPos] -= (uint)mc; + mc >>= 32; + if (remainder [nPos] > t) mc++; + dPos++; nPos++; + } while (dPos < divisorLen); + + nPos = pos - divisorLen + 1; + dPos = 0; + + // Overestimate + if (mc != 0) { + uint_q_hat--; + ulong sum = 0; + + do { + sum = ((ulong)remainder [nPos]) + ((ulong)bi2.data [dPos]) + sum; + remainder [nPos] = (uint)sum; + sum >>= 32; + dPos++; nPos++; + } while (dPos < divisorLen); + + } + + quot.data [resultPos--] = (uint)uint_q_hat; + + pos--; + j--; + } + + quot.Normalize (); + rem.Normalize (); + BigInteger [] ret = new BigInteger [2] { quot, rem }; + + if (shift != 0) + ret [1] >>= shift; + + return ret; + } + + #endregion + + #endregion + + #region Shift + public static BigInteger LeftShift (BigInteger bi, int n) + { + if (n == 0) return new BigInteger (bi, bi.length + 1); + + int w = n >> 5; + n &= ((1 << 5) - 1); + + BigInteger ret = new BigInteger (Sign.Positive, bi.length + 1 + (uint)w); + + uint i = 0, l = bi.length; + if (n != 0) { + uint x, carry = 0; + while (i < l) { + x = bi.data [i]; + ret.data [i + w] = (x << n) | carry; + carry = x >> (32 - n); + i++; + } + ret.data [i + w] = carry; + } else { + while (i < l) { + ret.data [i + w] = bi.data [i]; + i++; + } + } + + ret.Normalize (); + return ret; + } + + public static BigInteger RightShift (BigInteger bi, int n) + { + if (n == 0) return new BigInteger (bi); + + int w = n >> 5; + int s = n & ((1 << 5) - 1); + + BigInteger ret = new BigInteger (Sign.Positive, bi.length - (uint)w + 1); + uint l = (uint)ret.data.Length - 1; + + if (s != 0) { + + uint x, carry = 0; + + while (l-- > 0) { + x = bi.data [l + w]; + ret.data [l] = (x >> n) | carry; + carry = x << (32 - n); + } + } else { + while (l-- > 0) + ret.data [l] = bi.data [l + w]; + + } + ret.Normalize (); + return ret; + } + + #endregion + + #region Multiply + + public static BigInteger MultiplyByDword (BigInteger n, uint f) + { + BigInteger ret = new BigInteger (Sign.Positive, n.length + 1); + + uint i = 0; + ulong c = 0; + + do { + c += (ulong)n.data [i] * (ulong)f; + ret.data [i] = (uint)c; + c >>= 32; + } while (++i < n.length); + ret.data [i] = (uint)c; + ret.Normalize (); + return ret; + + } + + /// <summary> + /// Multiplies the data in x [xOffset:xOffset+xLen] by + /// y [yOffset:yOffset+yLen] and puts it into + /// d [dOffset:dOffset+xLen+yLen]. + /// </summary> + public static void Multiply(uint[] x, uint xOffset, uint xLen, uint[] y, uint yOffset, uint yLen, uint[] d, uint dOffset) + { + uint xx = 0, yy = 0, dd = 0; + uint xP = xx + xOffset, + xE = xP + xLen, + yB = yy + yOffset, + yE = yB + yLen, + dB = dd + dOffset; + + for (; xP < xE; xP++, dB++) { + + if (x[xP] == 0) continue; + + ulong mcarry = 0; + + uint dP = dB; + for (uint yP = yB; yP < yE; yP++, dP++) { + mcarry += ((ulong)x[xP] * (ulong)y[yP]) + (ulong)d[dP]; + + d[dP] = (uint)mcarry; + mcarry >>= 32; + } + + if (mcarry != 0) + d[dP] = (uint)mcarry; + } + } + + /// <summary> + /// Multiplies the data in x [xOffset:xOffset+xLen] by + /// y [yOffset:yOffset+yLen] and puts the low mod words into + /// d [dOffset:dOffset+mod]. + /// </summary> + public static void MultiplyMod2p32pmod(uint[] x, int xOffset, int xLen, uint[] y, int yOffest, int yLen, uint[] d, int dOffset, int mod) + { + uint xx = 0, yy = 0, dd = 0; + uint xP = (uint)(xx + xOffset), + xE = (uint)(xP + xLen), + yB = (uint)(yy + yOffest), + yE = (uint)(yB + yLen), + dB = (uint)(dd + dOffset), + dE = (uint)(dB + mod); + + for (; xP < xE; xP++, dB++) + { + + if (x[xP] == 0) continue; + + ulong mcarry = 0; + uint dP = dB; + for (uint yP = yB; yP < yE && dP < dE; yP++, dP++) + { + mcarry += ((ulong)x[xP] * (ulong)y[yP]) + (ulong)d[dP]; + + d[dP] = (uint)mcarry; + mcarry >>= 32; + } + + if (mcarry != 0 && dP < dE) + d[dP] = (uint)mcarry; + } + } + + public static void SquarePositive(BigInteger bi, ref uint[] wkSpace) { + uint[] t = wkSpace; + wkSpace = bi.data; + uint[] d = bi.data; + uint dl = bi.length; + bi.data = t; + + uint dd = 0, tt = 0; + + uint ttE = (uint)t.Length; + // Clear the dest + for (uint ttt = tt; ttt < ttE; ttt++) + t[ttt] = 0; + + uint dP = dd, tP = tt; + + for (uint i = 0; i < dl; i++, dP++) { + if (d[dP] == 0) + continue; + + ulong mcarry = 0; + uint bi1val = d[dP]; + + uint dP2 = dP + 1, tP2 = tP + 2 * i + 1; + + for (uint j = i + 1; j < dl; j++, tP2++, dP2++) { + // k = i + j + mcarry += ((ulong)bi1val * (ulong)d[dP2]) + t[tP2]; + + t[tP2] = (uint)mcarry; + mcarry >>= 32; + } + + if (mcarry != 0) + t[tP2] = (uint)mcarry; + } + + // Double t. Inlined for speed. + + tP = tt; + + uint x, carry = 0; + while (tP < ttE) { + x = t[tP]; + t[tP] = (x << 1) | carry; + carry = x >> (32 - 1); + tP++; + } + if (carry != 0) t[tP] = carry; + + // Add in the diagnals + + dP = dd; + tP = tt; + for (uint dE = dP + dl; (dP < dE); dP++, tP++) { + ulong val = (ulong)d[dP] * (ulong)d[dP] + t[tP]; + t[tP] = (uint)val; + val >>= 32; + t[(++tP)] += (uint)val; + if (t[tP] < (uint)val) { + uint tP3 = tP; + // Account for the first carry + (t[++tP3])++; + + // Keep adding until no carry + while ((t[tP3++]) == 0x0) + (t[tP3])++; + } + + } + + bi.length <<= 1; + + // Normalize length + while (t[tt + bi.length - 1] == 0 && bi.length > 1) bi.length--; + + } +#if UNUSED + public static bool Double (uint [] u, int l) + { + uint x, carry = 0; + uint i = 0; + while (i < l) { + x = u [i]; + u [i] = (x << 1) | carry; + carry = x >> (32 - 1); + i++; + } + if (carry != 0) u [l] = carry; + return carry != 0; + } +#endif + #endregion + + #region Number Theory + + public static BigInteger gcd (BigInteger a, BigInteger b) + { + BigInteger x = a; + BigInteger y = b; + + BigInteger g = y; + + while (x.length > 1) { + g = x; + x = y % x; + y = g; + + } + if (x == 0) return g; + + // TODO: should we have something here if we can convert to long? + + // + // Now we can just do it with single precision. I am using the binary gcd method, + // as it should be faster. + // + + uint yy = x.data [0]; + uint xx = y % yy; + + int t = 0; + + while (((xx | yy) & 1) == 0) { + xx >>= 1; yy >>= 1; t++; + } + while (xx != 0) { + while ((xx & 1) == 0) xx >>= 1; + while ((yy & 1) == 0) yy >>= 1; + if (xx >= yy) + xx = (xx - yy) >> 1; + else + yy = (yy - xx) >> 1; + } + + return yy << t; + } + + public static uint modInverse (BigInteger bi, uint modulus) + { + uint a = modulus, b = bi % modulus; + uint p0 = 0, p1 = 1; + + while (b != 0) { + if (b == 1) + return p1; + p0 += (a / b) * p1; + a %= b; + + if (a == 0) + break; + if (a == 1) + return modulus-p0; + + p1 += (b / a) * p0; + b %= a; + + } + return 0; + } + + public static BigInteger modInverse (BigInteger bi, BigInteger modulus) + { + if (modulus.length == 1) return modInverse (bi, modulus.data [0]); + + BigInteger [] p = { 0, 1 }; + BigInteger [] q = new BigInteger [2]; // quotients + BigInteger [] r = { 0, 0 }; // remainders + + int step = 0; + + BigInteger a = modulus; + BigInteger b = bi; + + ModulusRing mr = new ModulusRing (modulus); + + while (b != 0) { + + if (step > 1) { + + BigInteger pval = mr.Difference (p [0], p [1] * q [0]); + p [0] = p [1]; p [1] = pval; + } + + BigInteger [] divret = multiByteDivide (a, b); + + q [0] = q [1]; q [1] = divret [0]; + r [0] = r [1]; r [1] = divret [1]; + a = b; + b = divret [1]; + + step++; + } + + if (r [0] != 1) + throw (new ArithmeticException ("No inverse!")); + + return mr.Difference (p [0], p [1] * q [0]); + + } + #endregion + } + } +} |