diff --git a/crypto/src/crypto/engines/RFC3211WrapEngine.cs b/crypto/src/crypto/engines/RFC3211WrapEngine.cs
index 4e3af5227..86480145c 100644
--- a/crypto/src/crypto/engines/RFC3211WrapEngine.cs
+++ b/crypto/src/crypto/engines/RFC3211WrapEngine.cs
@@ -32,10 +32,10 @@ namespace Org.BouncyCastle.Crypto.Engines
if (param is ParametersWithRandom)
{
- ParametersWithRandom p = (ParametersWithRandom) param;
+ ParametersWithRandom p = (ParametersWithRandom)param;
- this.rand = p.Random;
- this.param = (ParametersWithIV) p.Parameters;
+ this.rand = p.Random;
+ this.param = p.Parameters as ParametersWithIV;
}
else
{
@@ -44,9 +44,12 @@ namespace Org.BouncyCastle.Crypto.Engines
rand = new SecureRandom();
}
- this.param = (ParametersWithIV) param;
- }
- }
+ this.param = param as ParametersWithIV;
+ }
+
+ if (null == this.param)
+ throw new ArgumentException("RFC3211Wrap requires an IV", "param");
+ }
public virtual string AlgorithmName
{
@@ -59,11 +62,11 @@ namespace Org.BouncyCastle.Crypto.Engines
int inLen)
{
if (!forWrapping)
- {
throw new InvalidOperationException("not set for wrapping");
- }
+ if (inLen > 255 || inLen < 0)
+ throw new ArgumentException("input must be from 0 to 255 bytes", "inLen");
- engine.Init(true, param);
+ engine.Init(true, param);
int blockSize = engine.GetBlockSize();
byte[] cekBlock;
@@ -78,15 +81,16 @@ namespace Org.BouncyCastle.Crypto.Engines
}
cekBlock[0] = (byte)inLen;
- cekBlock[1] = (byte)~inBytes[inOff];
- cekBlock[2] = (byte)~inBytes[inOff + 1];
- cekBlock[3] = (byte)~inBytes[inOff + 2];
Array.Copy(inBytes, inOff, cekBlock, 4, inLen);
rand.NextBytes(cekBlock, inLen + 4, cekBlock.Length - inLen - 4);
- for (int i = 0; i < cekBlock.Length; i += blockSize)
+ cekBlock[1] = (byte)~cekBlock[4];
+ cekBlock[2] = (byte)~cekBlock[4 + 1];
+ cekBlock[3] = (byte)~cekBlock[4 + 2];
+
+ for (int i = 0; i < cekBlock.Length; i += blockSize)
{
engine.ProcessBlock(cekBlock, i, cekBlock, i);
}
@@ -142,27 +146,34 @@ namespace Org.BouncyCastle.Crypto.Engines
engine.ProcessBlock(cekBlock, i, cekBlock, i);
}
- if ((cekBlock[0] & 0xff) > cekBlock.Length - 4)
- {
- throw new InvalidCipherTextException("wrapped key corrupted");
- }
+ bool invalidLength = (int)cekBlock[0] > (cekBlock.Length - 4);
- byte[] key = new byte[cekBlock[0] & 0xff];
+ byte[] key;
+ if (invalidLength)
+ {
+ key = new byte[cekBlock.Length - 4];
+ }
+ else
+ {
+ key = new byte[cekBlock[0]];
+ }
- Array.Copy(cekBlock, 4, key, 0, cekBlock[0]);
+ Array.Copy(cekBlock, 4, key, 0, key.Length);
// Note: Using constant time comparison
int nonEqual = 0;
for (int i = 0; i != 3; i++)
{
byte check = (byte)~cekBlock[1 + i];
- nonEqual |= (check ^ key[i]);
- }
+ nonEqual |= (check ^ cekBlock[4 + i]);
+ }
+
+ Array.Clear(cekBlock, 0, cekBlock.Length);
- if (nonEqual != 0)
- throw new InvalidCipherTextException("wrapped key fails checksum");
+ if (nonEqual != 0 | invalidLength)
+ throw new InvalidCipherTextException("wrapped key corrupted");
- return key;
+ return key;
}
}
}
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