diff --git a/crypto/src/crypto/modes/SicBlockCipher.cs b/crypto/src/crypto/modes/SicBlockCipher.cs
index da7ed7859..239f99478 100644
--- a/crypto/src/crypto/modes/SicBlockCipher.cs
+++ b/crypto/src/crypto/modes/SicBlockCipher.cs
@@ -3,6 +3,8 @@ using System;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
+using Org.BouncyCastle.Utilities;
+
namespace Org.BouncyCastle.Crypto.Modes
{
/**
@@ -14,9 +16,9 @@ namespace Org.BouncyCastle.Crypto.Modes
{
private readonly IBlockCipher cipher;
private readonly int blockSize;
- private readonly byte[] IV;
private readonly byte[] counter;
private readonly byte[] counterOut;
+ private byte[] IV;
/**
* Basic constructor.
@@ -27,9 +29,9 @@ namespace Org.BouncyCastle.Crypto.Modes
{
this.cipher = cipher;
this.blockSize = cipher.GetBlockSize();
- this.IV = new byte[blockSize];
this.counter = new byte[blockSize];
this.counterOut = new byte[blockSize];
+ this.IV = new byte[blockSize];
}
/**
@@ -37,51 +39,51 @@ namespace Org.BouncyCastle.Crypto.Modes
*
* @return the underlying block cipher that we are wrapping.
*/
- public IBlockCipher GetUnderlyingCipher()
+ public virtual IBlockCipher GetUnderlyingCipher()
{
return cipher;
}
- public void Init(
+ public virtual void Init(
bool forEncryption, //ignored by this CTR mode
ICipherParameters parameters)
{
- if (parameters is ParametersWithIV)
- {
- ParametersWithIV ivParam = (ParametersWithIV) parameters;
- byte[] iv = ivParam.GetIV();
- Array.Copy(iv, 0, IV, 0, IV.Length);
+ ParametersWithIV ivParam = parameters as ParametersWithIV;
+ if (ivParam == null)
+ throw new ArgumentException("CTR/SIC mode requires ParametersWithIV", "parameters");
- Reset();
+ this.IV = Arrays.Clone(ivParam.GetIV());
- // if null it's an IV changed only.
- if (ivParam.Parameters != null)
- {
- cipher.Init(true, ivParam.Parameters);
- }
- }
- else
+ if (blockSize < IV.Length)
+ throw new ArgumentException("CTR/SIC mode requires IV no greater than: " + blockSize + " bytes.");
+ if (blockSize - IV.Length > 8)
+ throw new ArgumentException("CTR/SIC mode requires IV of at least: " + (blockSize - 8) + " bytes.");
+
+ Reset();
+
+ // if null it's an IV changed only.
+ if (ivParam.Parameters != null)
{
- throw new ArgumentException("SIC mode requires ParametersWithIV", "parameters");
+ cipher.Init(true, ivParam.Parameters);
}
}
- public string AlgorithmName
+ public virtual string AlgorithmName
{
get { return cipher.AlgorithmName + "/SIC"; }
}
- public bool IsPartialBlockOkay
+ public virtual bool IsPartialBlockOkay
{
get { return true; }
}
- public int GetBlockSize()
+ public virtual int GetBlockSize()
{
return cipher.GetBlockSize();
}
- public int ProcessBlock(
+ public virtual int ProcessBlock(
byte[] input,
int inOff,
byte[] output,
@@ -106,9 +108,10 @@ namespace Org.BouncyCastle.Crypto.Modes
return counter.Length;
}
- public void Reset()
+ public virtual void Reset()
{
- Array.Copy(IV, 0, counter, 0, counter.Length);
+ Arrays.Fill(counter, (byte)0);
+ Array.Copy(IV, 0, counter, 0, IV.Length);
cipher.Reset();
}
}
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