|
public static Encrypt ( byte masterKey, ArraySegment |
||
| masterKey | byte | |
| plaintext | ArraySegment |
|
| salt | ArraySegment |
|
| counter | uint | |
| return | byte[] | |
public int TransformBlock(byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset)
{
int partialBlockSize = inputCount % EtM_Transform_Constants.INPUT_BLOCK_SIZE;
int fullBlockSize = inputCount - partialBlockSize;
if (partialBlockSize != 0)
throw new Exception("inputCount must be a multiple of input block size (" + EtM_Transform_Constants.INPUT_BLOCK_SIZE.ToString() + ").");
int i = 0, j = 0;
if (fullBlockSize > 0)
{
for (; i < fullBlockSize; i += EtM_Transform_Constants.INPUT_BLOCK_SIZE, j += EtM_Transform_Constants.OUTPUT_BLOCK_SIZE)
{
EtM_CTR.Encrypt(
masterKey: this.key,
plaintext: new ArraySegment<byte>(inputBuffer, inputOffset + i, EtM_Transform_Constants.INPUT_BLOCK_SIZE),
output: outputBuffer,
outputOffset: outputOffset + j,
salt: this.salt,
counter: this.currentChunkNumber);
if (this.currentChunkNumber == EtM_Transform_Constants.INITIAL_CHUNK_NUMBER)
{
EtM_EncryptTransform.PrependSaltWith1stBlockContext(ref this.salt, outputBuffer, outputOffset);
}
checked { ++this.currentChunkNumber; }
}
}
return j;
}// TransformBlock()
}// TransformBlock()
public byte[] TransformFinalBlock(byte[] inputBuffer, int inputOffset, int inputCount)
{
if (this.key == null) return null; // key would be null if this instance has already been disposed
if (inputCount >= EtM_Transform_Constants.INPUT_BLOCK_SIZE)
throw new Exception("Final input block size must be smaller than " + EtM_Transform_Constants.INPUT_BLOCK_SIZE.ToString() + ".");
byte[] outputBuffer = new byte[EtM_Transform_Constants.ETM_CTR_OVERHEAD + inputCount];
EtM_CTR.Encrypt(
masterKey: this.key,
plaintext: new ArraySegment<byte>(inputBuffer, inputOffset, inputCount),
output: outputBuffer,
outputOffset: 0,
salt: this.salt,
counter: this.currentChunkNumber);
this.Dispose();
return outputBuffer;
}// TransformFinalBlock()
public static byte[] Encrypt(byte[] masterKey, ArraySegment<byte> plaintext, ArraySegment<byte>? salt = null)
{
return EtM_CTR.Encrypt(masterKey, plaintext, salt);
}
}// Encrypt()
public static byte[] Encrypt(byte[] masterKey, ArraySegment<byte> plaintext, ArraySegment<byte>? salt = null, uint counter = 1)
{
byte[] buffer = new byte[CONTEXT_BUFFER_LENGTH + plaintext.Count + MAC_LENGTH];
EtM_CTR.Encrypt(masterKey: masterKey, plaintext: plaintext, output: buffer, outputOffset: 0, salt: salt, counter: counter);
return buffer;
}// Encrypt()