68 lines
1.9 KiB
C#
68 lines
1.9 KiB
C#
using System;
|
|
|
|
using Org.BouncyCastle.Crypto.Parameters;
|
|
|
|
namespace Org.BouncyCastle.Crypto.Generators
|
|
{
|
|
public class DesEdeKeyGenerator
|
|
: DesKeyGenerator
|
|
{
|
|
public DesEdeKeyGenerator()
|
|
{
|
|
}
|
|
|
|
internal DesEdeKeyGenerator(
|
|
int defaultStrength)
|
|
: base(defaultStrength)
|
|
{
|
|
}
|
|
|
|
/**
|
|
* initialise the key generator - if strength is set to zero
|
|
* the key Generated will be 192 bits in size, otherwise
|
|
* strength can be 128 or 192 (or 112 or 168 if you don't count
|
|
* parity bits), depending on whether you wish to do 2-key or 3-key
|
|
* triple DES.
|
|
*
|
|
* @param param the parameters to be used for key generation
|
|
*/
|
|
protected override void engineInit(
|
|
KeyGenerationParameters parameters)
|
|
{
|
|
this.random = parameters.Random;
|
|
this.strength = (parameters.Strength + 7) / 8;
|
|
|
|
if (strength == 0 || strength == (168 / 8))
|
|
{
|
|
strength = DesEdeParameters.DesEdeKeyLength;
|
|
}
|
|
else if (strength == (112 / 8))
|
|
{
|
|
strength = 2 * DesEdeParameters.DesKeyLength;
|
|
}
|
|
else if (strength != DesEdeParameters.DesEdeKeyLength
|
|
&& strength != (2 * DesEdeParameters.DesKeyLength))
|
|
{
|
|
throw new ArgumentException("DESede key must be "
|
|
+ (DesEdeParameters.DesEdeKeyLength * 8) + " or "
|
|
+ (2 * 8 * DesEdeParameters.DesKeyLength)
|
|
+ " bits long.");
|
|
}
|
|
}
|
|
|
|
protected override byte[] engineGenerateKey()
|
|
{
|
|
byte[] newKey;
|
|
|
|
do
|
|
{
|
|
newKey = random.GenerateSeed(strength);
|
|
DesEdeParameters.SetOddParity(newKey);
|
|
}
|
|
while (DesEdeParameters.IsWeakKey(newKey, 0, newKey.Length));
|
|
|
|
return newKey;
|
|
}
|
|
}
|
|
}
|