using Org.BouncyCastle.Math; using Org.BouncyCastle.Utilities; using System; namespace Org.BouncyCastle.Crypto.Parameters { public class RsaKeyParameters : AsymmetricKeyParameter { private static readonly BigInteger SmallPrimesProduct = new BigInteger("8138e8a0fcf3a4e84a771d40fd305d7f4aa59306d7251de54d98af8fe95729a1f73d893fa424cd2edc8636a6c3285e022b0e3866a565ae8108eed8591cd4fe8d2ce86165a978d719ebf647f362d33fca29cd179fb42401cbaf3df0c614056f9c8f3cfd51e474afb6bc6974f78db8aba8e9e517fded658591ab7502bd41849462f", 16); private readonly BigInteger modulus; private readonly BigInteger exponent; public BigInteger Modulus => modulus; public BigInteger Exponent => exponent; private static bool HasAnySmallFactors(BigInteger modulus) { BigInteger m = modulus; BigInteger x = SmallPrimesProduct; if (modulus.BitLength < SmallPrimesProduct.BitLength) { m = SmallPrimesProduct; x = modulus; } return !BigIntegers.ModOddIsCoprimeVar(m, x); } private static BigInteger Validate(BigInteger modulus) { if ((modulus.IntValue & 1) == 0) throw new ArgumentException("RSA modulus is even", "modulus"); int num = ImplGetInteger("Org.BouncyCastle.Rsa.MaxSize", 16384); if (modulus.BitLength > num) throw new ArgumentException("RSA modulus out of range", "modulus"); if (HasAnySmallFactors(modulus)) throw new ArgumentException("RSA modulus has a small prime factor", "modulus"); return modulus; } public RsaKeyParameters(bool isPrivate, BigInteger modulus, BigInteger exponent) : base(isPrivate) { if (modulus == null) throw new ArgumentNullException("modulus"); if (exponent == null) throw new ArgumentNullException("exponent"); if (modulus.SignValue <= 0) throw new ArgumentException("Not a valid RSA modulus", "modulus"); if (exponent.SignValue <= 0) throw new ArgumentException("Not a valid RSA exponent", "exponent"); if (!isPrivate && (exponent.IntValue & 1) == 0) throw new ArgumentException("RSA publicExponent is even", "exponent"); this.modulus = Validate(modulus); this.exponent = exponent; } public override bool Equals(object obj) { RsaKeyParameters rsaKeyParameters = obj as RsaKeyParameters; if (rsaKeyParameters == null) return false; if (rsaKeyParameters.IsPrivate == base.IsPrivate && rsaKeyParameters.Modulus.Equals(modulus)) return rsaKeyParameters.Exponent.Equals(exponent); return false; } public override int GetHashCode() { return modulus.GetHashCode() ^ exponent.GetHashCode() ^ base.IsPrivate.GetHashCode(); } private static int ImplGetInteger(string envVariable, int defaultValue) { if (!int.TryParse(Platform.GetEnvironmentVariable(envVariable), out int result)) return defaultValue; return result; } } }