diff --git a/crypto/src/crypto/engines/AesWrapEngine.cs b/crypto/src/crypto/engines/AesWrapEngine.cs
index bf9e724cd..641e22f78 100644
--- a/crypto/src/crypto/engines/AesWrapEngine.cs
+++ b/crypto/src/crypto/engines/AesWrapEngine.cs
@@ -1,16 +1,30 @@
namespace Org.BouncyCastle.Crypto.Engines
{
- /// <remarks>
- /// An implementation of the AES Key Wrapper from the NIST Key Wrap Specification.
- /// <p/>
- /// For further details see: <a href="http://csrc.nist.gov/encryption/kms/key-wrap.pdf">http://csrc.nist.gov/encryption/kms/key-wrap.pdf</a>.
- /// </remarks>
- public class AesWrapEngine
+ /// <remarks>
+ /// An implementation of the AES Key Wrapper from the NIST Key Wrap Specification.
+ /// <p/>
+ /// For further details see: <a href="http://csrc.nist.gov/encryption/kms/key-wrap.pdf">http://csrc.nist.gov/encryption/kms/key-wrap.pdf</a>.
+ /// </remarks>
+ public class AesWrapEngine
: Rfc3394WrapEngine
{
- public AesWrapEngine()
+ /// <summary>
+ /// Create a regular AesWrapEngine specifying the encrypt for wrapping, decrypt for unwrapping.
+ /// </summary>
+ public AesWrapEngine()
: base(AesUtilities.CreateEngine())
{
}
- }
+
+ /// <summary>
+ /// Create an AESWrapEngine where the underlying cipher is (optionally) set to decrypt for wrapping, encrypt for
+ /// unwrapping.
+ /// </summary>
+ /// <param name="useReverseDirection">true if underlying cipher should be used in decryption mode, false
+ /// otherwise.</param>
+ public AesWrapEngine(bool useReverseDirection)
+ : base(AesUtilities.CreateEngine(), useReverseDirection)
+ {
+ }
+ }
}
diff --git a/crypto/src/crypto/engines/RFC3394WrapEngine.cs b/crypto/src/crypto/engines/RFC3394WrapEngine.cs
index ff3a4e0a0..9744130d2 100644
--- a/crypto/src/crypto/engines/RFC3394WrapEngine.cs
+++ b/crypto/src/crypto/engines/RFC3394WrapEngine.cs
@@ -16,22 +16,24 @@ namespace Org.BouncyCastle.Crypto.Engines
: IWrapper
{
private readonly IBlockCipher engine;
+ private readonly bool wrapCipherMode;
- private KeyParameter param;
+ private KeyParameter param;
private bool forWrapping;
- private byte[] iv =
- {
- 0xa6, 0xa6, 0xa6, 0xa6,
- 0xa6, 0xa6, 0xa6, 0xa6
- };
+ private byte[] iv = { 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6 };
- public Rfc3394WrapEngine(
- IBlockCipher engine)
+ public Rfc3394WrapEngine(IBlockCipher engine)
+ : this(engine, false)
{
- this.engine = engine;
}
+ public Rfc3394WrapEngine(IBlockCipher engine, bool useReverseDirection)
+ {
+ this.engine = engine;
+ this.wrapCipherMode = !useReverseDirection;
+ }
+
public virtual void Init(
bool forWrapping,
ICipherParameters parameters)
@@ -69,111 +71,113 @@ namespace Org.BouncyCastle.Crypto.Engines
get { return engine.AlgorithmName; }
}
- public virtual byte[] Wrap(
- byte[] input,
- int inOff,
- int inLen)
+ public virtual byte[] Wrap(byte[] input, int inOff, int inLen)
{
if (!forWrapping)
- {
throw new InvalidOperationException("not set for wrapping");
- }
+ if (inLen < 8)
+ throw new DataLengthException("wrap data must be at least 8 bytes");
- int n = inLen / 8;
+ int n = inLen / 8;
if ((n * 8) != inLen)
- {
throw new DataLengthException("wrap data must be a multiple of 8 bytes");
- }
- byte[] block = new byte[inLen + iv.Length];
- byte[] buf = new byte[8 + iv.Length];
+ engine.Init(wrapCipherMode, param);
+ byte[] block = new byte[inLen + iv.Length];
Array.Copy(iv, 0, block, 0, iv.Length);
Array.Copy(input, inOff, block, iv.Length, inLen);
- engine.Init(true, param);
-
- for (int j = 0; j != 6; j++)
+ if (n == 1)
{
- for (int i = 1; i <= n; i++)
- {
- Array.Copy(block, 0, buf, 0, iv.Length);
- Array.Copy(block, 8 * i, buf, iv.Length, 8);
- engine.ProcessBlock(buf, 0, buf, 0);
+ engine.ProcessBlock(block, 0, block, 0);
+ }
+ else
+ {
+ byte[] buf = new byte[8 + iv.Length];
- int t = n * j + i;
- for (int k = 1; t != 0; k++)
+ for (int j = 0; j != 6; j++)
+ {
+ for (int i = 1; i <= n; i++)
{
- byte v = (byte)t;
+ Array.Copy(block, 0, buf, 0, iv.Length);
+ Array.Copy(block, 8 * i, buf, iv.Length, 8);
+ engine.ProcessBlock(buf, 0, buf, 0);
- buf[iv.Length - k] ^= v;
- t = (int) ((uint)t >> 8);
- }
+ int t = n * j + i;
+ for (int k = 1; t != 0; k++)
+ {
+ byte v = (byte)t;
- Array.Copy(buf, 0, block, 0, 8);
- Array.Copy(buf, 8, block, 8 * i, 8);
+ buf[iv.Length - k] ^= v;
+ t = (int) ((uint)t >> 8);
+ }
+
+ Array.Copy(buf, 0, block, 0, 8);
+ Array.Copy(buf, 8, block, 8 * i, 8);
+ }
}
- }
+ }
- return block;
+ return block;
}
- public virtual byte[] Unwrap(
- byte[] input,
- int inOff,
- int inLen)
+ public virtual byte[] Unwrap(byte[] input, int inOff, int inLen)
{
if (forWrapping)
- {
throw new InvalidOperationException("not set for unwrapping");
- }
- if (inLen < iv.Length)
- {
+ if (inLen < 16)
throw new InvalidCipherTextException("unwrap data too short");
- }
int n = inLen / 8;
if ((n * 8) != inLen)
- {
throw new InvalidCipherTextException("unwrap data must be a multiple of 8 bytes");
- }
-
- byte[] block = new byte[inLen - iv.Length];
- byte[] a = new byte[iv.Length];
- byte[] buf = new byte[8 + iv.Length];
- Array.Copy(input, inOff, a, 0, iv.Length);
- Array.Copy(input, inOff + iv.Length, block, 0, inLen - iv.Length);
+ engine.Init(!wrapCipherMode, param);
- engine.Init(false, param);
+ byte[] block = new byte[inLen - iv.Length];
+ byte[] a = new byte[iv.Length];
+ byte[] buf = new byte[8 + iv.Length];
n = n - 1;
- for (int j = 5; j >= 0; j--)
+ if (n == 1)
{
- for (int i = n; i >= 1; i--)
- {
- Array.Copy(a, 0, buf, 0, iv.Length);
- Array.Copy(block, 8 * (i - 1), buf, iv.Length, 8);
+ engine.ProcessBlock(input, inOff, buf, 0);
+ Array.Copy(buf, 0, a, 0, iv.Length);
+ Array.Copy(buf, iv.Length, block, 0, 8);
+ }
+ else
+ {
+ Array.Copy(input, inOff, a, 0, iv.Length);
+ Array.Copy(input, inOff + iv.Length, block, 0, inLen - iv.Length);
- int t = n * j + i;
- for (int k = 1; t != 0; k++)
+ for (int j = 5; j >= 0; j--)
+ {
+ for (int i = n; i >= 1; i--)
{
- byte v = (byte)t;
+ Array.Copy(a, 0, buf, 0, iv.Length);
+ Array.Copy(block, 8 * (i - 1), buf, iv.Length, 8);
- buf[iv.Length - k] ^= v;
- t = (int) ((uint)t >> 8);
- }
+ int t = n * j + i;
+ for (int k = 1; t != 0; k++)
+ {
+ byte v = (byte)t;
- engine.ProcessBlock(buf, 0, buf, 0);
- Array.Copy(buf, 0, a, 0, 8);
- Array.Copy(buf, 8, block, 8 * (i - 1), 8);
+ buf[iv.Length - k] ^= v;
+ t = (int) ((uint)t >> 8);
+ }
+
+ engine.ProcessBlock(buf, 0, buf, 0);
+ Array.Copy(buf, 0, a, 0, 8);
+ Array.Copy(buf, 8, block, 8 * (i - 1), 8);
+ }
}
- }
+ }
- if (!Arrays.FixedTimeEquals(a, iv))
+ if (!Arrays.FixedTimeEquals(a, iv))
throw new InvalidCipherTextException("checksum failed");
return block;
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