Class AesGcmDecryptStream

Namespace

Amazon.Extensions.S3.Encryption.Util

Assembly

Amazon.Extensions.S3.Encryption.dll

A wrapper stream that decrypts the base stream using AES GCM algorithm as it is being read.

public class AesGcmDecryptStream : DecryptStream, IDisposable

Inheritance

object

MarshalByRefObject

Stream

WrapperStream

DecryptStream

AesGcmDecryptStream

Implements

IDisposable

Constructors

AesGcmDecryptStream(Stream, byte[], byte[], int, byte[])

Constructor for initializing decryption stream

public AesGcmDecryptStream(Stream baseStream, byte[] key, byte[] nonce, int tagSize, byte[] associatedText = null)

Parameters

baseStream Stream

Original data stream

key byte[]

Key to be used for decryption

nonce byte[]

Nonce to be used for decryption

tagSize int

Tag size for the tag appended in the end of the stream

associatedText byte[]

Additional associated data

Methods

Read(byte[], int, int)

Reads a sequence of encrypted bytes from the current stream and advances the position within the stream by the number of bytes read.

public override int Read(byte[] buffer, int offset, int count)

Parameters

buffer byte[]

An array of bytes. When this method returns, the buffer contains the specified byte array with the values between offset and (offset + count - 1) replaced by the bytes read from the current source.

offset int

The zero-based byte offset in buffer at which to begin storing the data read from the current stream.

count int

The maximum number of bytes to be read from the current stream.

Returns

int

The total number of bytes read into the buffer. This can be less than the number of bytes requested if that many bytes are not currently available, or zero (0) if the end of the stream has been reached.

Exceptions

AmazonCryptoException

Underlying crypto exception wrapped in Amazon exception

ReadAsync(byte[], int, int, CancellationToken)

Asynchronously reads a sequence of decrypted bytes from the current stream, advances the position within the stream by the number of bytes read, and monitors cancellation requests.

public override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)

Parameters

buffer byte[]

An array of bytes. When this method returns, the buffer contains the specified byte array with the values between offset and (offset + count - 1) replaced by the bytes read from the current source.

offset int

The zero-based byte offset in buffer at which to begin storing the data read from the current stream.

count int

The maximum number of bytes to be read from the current stream.

cancellationToken CancellationToken

The token to monitor for cancellation requests. The default value is System.Threading.CancellationToken.None.

Returns

Task<int>

A task that represents the asynchronous read operation. The value of the TResult parameter contains the total number of bytes read into the buffer. This can be less than the number of bytes requested if that many bytes are not currently available, or zero (0) if the end of the stream has been reached.

Exceptions

AmazonCryptoException

Underlying crypto exception wrapped in Amazon exception