67 lines
1.8 KiB
C#
67 lines
1.8 KiB
C#
using System;
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using Org.BouncyCastle.Crypto.Parameters;
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namespace Org.BouncyCastle.Crypto.Generators
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{
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public class DesEdeKeyGenerator
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: DesKeyGenerator
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{
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public DesEdeKeyGenerator()
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{
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}
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internal DesEdeKeyGenerator(
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int defaultStrength)
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: base(defaultStrength)
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{
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}
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/**
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* initialise the key generator - if strength is set to zero
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* the key Generated will be 192 bits in size, otherwise
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* strength can be 128 or 192 (or 112 or 168 if you don't count
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* parity bits), depending on whether you wish to do 2-key or 3-key
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* triple DES.
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*
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* @param param the parameters to be used for key generation
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*/
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protected override void engineInit(
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KeyGenerationParameters parameters)
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{
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base.engineInit(parameters);
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if (strength == 0 || strength == (168 / 8))
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{
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strength = DesEdeParameters.DesEdeKeyLength;
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}
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else if (strength == (112 / 8))
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{
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strength = 2 * DesEdeParameters.DesKeyLength;
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}
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else if (strength != DesEdeParameters.DesEdeKeyLength
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&& strength != (2 * DesEdeParameters.DesKeyLength))
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{
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throw new ArgumentException("DESede key must be "
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+ (DesEdeParameters.DesEdeKeyLength * 8) + " or "
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+ (2 * 8 * DesEdeParameters.DesKeyLength)
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+ " bits long.");
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}
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}
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protected override byte[] engineGenerateKey()
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{
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byte[] newKey;
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do
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{
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newKey = random.GenerateSeed(strength);
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DesEdeParameters.SetOddParity(newKey);
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}
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while (DesEdeParameters.IsWeakKey(newKey, 0, newKey.Length));
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return newKey;
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}
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}
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}
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