/// <summary>
/// decoding the data with security provider
/// </summary>
/// <param name="data">
/// a bytes data that contains the data to be decoded with security provider.
/// </param>
/// <returns>
/// a bytes data that contains the decoded data.
/// </returns>
/// <exception cref="ArgumentNullException">
/// thrown when data is null.
/// </exception>
public override byte[] Decode(byte[] data)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
// if the SASL security provider is not ready, do not decode.
if (this.securityContext.NeedContinueProcessing ||
!this.UsingMessageSecurity)
{
this.consumedData = false;
return(data);
}
// store the data to buffer.
this.receivedBuffer.AddReceivedData(data);
this.consumedData = true;
this.consumedLength = data.Length;
// SaslHeader is used to decode the whole packet from buffer.
AdtsLdapSaslSecurityHeader saslHeader = new AdtsLdapSaslSecurityHeader();
// unmarshal the sasl header
saslHeader.FromBytes(this.receivedBuffer.Peek(AdtsLdapSaslSecurityHeader.SIZE_OF_LENGTH));
// if the sasl header is not valid, maybe data is not enough, consumed the received data and return.
if (!saslHeader.IsValid(this.receivedBuffer.Length))
{
return(new byte[0]);
}
// update the signature length if needed
if (this.signatureLength < 0)
{
this.signatureLength = (int)this.securityContext.ContextSizes.MaxSignatureSize;
}
// get a copy of data.
byte[] bufferData = this.receivedBuffer.Data;
// get the signature.
byte[] signature = ArrayUtility.SubArray <byte>(
bufferData, AdtsLdapSaslSecurityHeader.SIZE_OF_LENGTH, this.signatureLength);
// get the encrypted message
byte[] encryptedMessage = ArrayUtility.SubArray <byte>(
bufferData, AdtsLdapSaslSecurityHeader.SIZE_OF_LENGTH + this.signatureLength,
saslHeader.Length - this.signatureLength);
// if the sasl header is valid, decrypt it with security provider.
byte[] decryptedMessage = this.securityContext.Decrypt(encryptedMessage, signature);
// remove the sasl header bytes data from the buffer.
this.receivedBuffer.Remove(AdtsLdapSaslSecurityHeader.SIZE_OF_LENGTH + saslHeader.Length);
return(decryptedMessage);
}
/// <summary>
/// decoding the data with security provider
/// </summary>
/// <param name="data">
/// a bytes data that contains the data to be decoded with security provider.
/// </param>
/// <returns>
/// a bytes data that contains the decoded data.
/// </returns>
/// <exception cref="ArgumentNullException">
/// thrown when data is null.
/// </exception>
public override byte[] Decode(byte[] data)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
// if the SASL security provider is not ready, do not decode.
if (this.securityContext.NeedContinueProcessing
|| !this.UsingMessageSecurity)
{
this.consumedData = false;
return data;
}
// store the data to buffer.
this.receivedBuffer.AddReceivedData(data);
this.consumedData = true;
this.consumedLength = data.Length;
// SaslHeader is used to decode the whole packet from buffer.
AdtsLdapSaslSecurityHeader saslHeader = new AdtsLdapSaslSecurityHeader();
// unmarshal the sasl header
saslHeader.FromBytes(this.receivedBuffer.Peek(AdtsLdapSaslSecurityHeader.SIZE_OF_LENGTH));
// if the sasl header is not valid, maybe data is not enough, consumed the received data and return.
if (!saslHeader.IsValid(this.receivedBuffer.Length))
{
return new byte[0];
}
// update the signature length if needed
if (this.signatureLength < 0)
{
this.signatureLength = (int)this.securityContext.ContextSizes.MaxSignatureSize;
}
// get a copy of data.
byte[] bufferData = this.receivedBuffer.Data;
// get the signature.
byte[] signature = ArrayUtility.SubArray<byte>(
bufferData, AdtsLdapSaslSecurityHeader.SIZE_OF_LENGTH, this.signatureLength);
// get the encrypted message
byte[] encryptedMessage = ArrayUtility.SubArray<byte>(
bufferData, AdtsLdapSaslSecurityHeader.SIZE_OF_LENGTH + this.signatureLength,
saslHeader.Length - this.signatureLength);
// if the sasl header is valid, decrypt it with security provider.
byte[] decryptedMessage = this.securityContext.Decrypt(encryptedMessage, signature);
// remove the sasl header bytes data from the buffer.
this.receivedBuffer.Remove(AdtsLdapSaslSecurityHeader.SIZE_OF_LENGTH + saslHeader.Length);
return decryptedMessage;
}