Пример #1
0
		/// <summary>
		/// Test an archive for integrity/validity
		/// </summary>
		/// <param name="testData">Perform low level data Crc check</param>
		/// <param name="strategy">The <see cref="TestStrategy"></see> to apply.</param>
		/// <param name="resultHandler">The <see cref="ZipTestResultHandler"></see> handler to call during testing.</param>
		/// <returns>true if all tests pass, false otherwise</returns>
		/// <exception cref="ObjectDisposedException">The object has already been closed.</exception>
		public bool TestArchive(bool testData, TestStrategy strategy, ZipTestResultHandler resultHandler)
		{
			if (isDisposed_) {
				throw new ObjectDisposedException("ZipFile");
			}
			
			TestStatus status = new TestStatus(this);

			if ( resultHandler != null ) {
				resultHandler(status, null);
			}

			HeaderTest test = testData ? (HeaderTest.Header | HeaderTest.Extract) : HeaderTest.Header;

			bool testing = true;

			try {
				int entryIndex = 0;

				while ( testing && (entryIndex < Count) ) {
					if ( resultHandler != null ) {
						status.SetEntry(this[entryIndex]);
						status.SetOperation(TestOperation.EntryHeader);
						resultHandler(status, null);
					}

					try	{
						TestLocalHeader(this[entryIndex], test);
					}
					catch(ZipException ex) {
						status.AddError();

						if ( resultHandler != null ) {
							resultHandler(status,
								string.Format("Exception during test - '{0}'", ex.Message));
						}

						if ( strategy == TestStrategy.FindFirstError ) {
							testing = false; 
						}
					}

					if ( testing && testData && this[entryIndex].IsFile ) {
						if ( resultHandler != null ) {
							status.SetOperation(TestOperation.EntryData);
							resultHandler(status, null);
						}

                        Crc32 crc = new Crc32();

                        using (Stream entryStream = this.GetInputStream(this[entryIndex]))
                        {

                            byte[] buffer = new byte[4096];
                            long totalBytes = 0;
                            int bytesRead;
                            while ((bytesRead = entryStream.Read(buffer, 0, buffer.Length)) > 0)
                            {
                                crc.Update(buffer, 0, bytesRead);

                                if (resultHandler != null)
                                {
                                    totalBytes += bytesRead;
                                    status.SetBytesTested(totalBytes);
                                    resultHandler(status, null);
                                }
                            }
                        }

						if (this[entryIndex].Crc != crc.Value) {
							status.AddError();
							
							if ( resultHandler != null ) {
								resultHandler(status, "CRC mismatch");
							}

							if ( strategy == TestStrategy.FindFirstError ) {
								testing = false;
							}
						}

						if (( this[entryIndex].Flags & (int)GeneralBitFlags.Descriptor) != 0 ) {
							ZipHelperStream helper = new ZipHelperStream(baseStream_);
							DescriptorData data = new DescriptorData();
							helper.ReadDataDescriptor(this[entryIndex].LocalHeaderRequiresZip64, data);
							if (this[entryIndex].Crc != data.Crc) {
								status.AddError();
							}

							if (this[entryIndex].CompressedSize != data.CompressedSize) {
								status.AddError();
							}

							if (this[entryIndex].Size != data.Size) {
								status.AddError();
							}
						}
					}

					if ( resultHandler != null ) {
						status.SetOperation(TestOperation.EntryComplete);
						resultHandler(status, null);
					}

					entryIndex += 1;
				}

				if ( resultHandler != null ) {
					status.SetOperation(TestOperation.MiscellaneousTests);
					resultHandler(status, null);
				}

				// TODO: the 'Corrina Johns' test where local headers are missing from
				// the central directory.  They are therefore invisible to many archivers.
			}
			catch (Exception ex) {
				status.AddError();

				if ( resultHandler != null ) {
					resultHandler(status, string.Format("Exception during test - '{0}'", ex.Message));
				}
			}

			if ( resultHandler != null ) {
				status.SetOperation(TestOperation.Complete);
				status.SetEntry(null);
				resultHandler(status, null);
			}

			return (status.ErrorCount == 0);
		}
            private byte[] IV(Salt secret, Salt salt)
            {
                // Long story, this has been a little difficult to finally settle upon an algorithm.
                // We know we don't want to the same value each time, and we prefer not to use only
                // the public salt.  My biggest concern is not generating a IV value that interacts
                // with AES in a way that might divulge information unintentionally.  Since we are
                // using the same values (salt+secret) to derive the IV this is a very real risk.
                // To mitigate this risk the primary interaction of secret in the derivation of this
                // value is compressed into a CRC of both the salt and secret.  This value is then 
                // masked with computations of salt to produce the 16 IV bytes needed.
                byte[] sbytes = salt.ToArray();
                byte[] result = new byte[16];
                // compute a mask from CRC32(salt + secret)
                int mask = new Crc32(_salt.GetData(secret.ToArray()).ToArray()).Value;
                // xor part of the mask with the sum of two salt bytes
                for (int i = 0; i < 16; i++)
                    result[i] = (byte)((mask >> i) ^ (sbytes[i] + sbytes[i + 16]));

                return result;
            }
Пример #3
0
		void CopyEntryDataDirect(ZipUpdate update, Stream stream, bool updateCrc, ref long destinationPosition, ref long sourcePosition)
		{
			long bytesToCopy = update.Entry.CompressedSize;
			
			// NOTE: Compressed size is updated elsewhere.
			Crc32 crc = new Crc32();
			byte[] buffer = GetBuffer();

			long targetBytes = bytesToCopy;
			long totalBytesRead = 0;

			int bytesRead;
			do
			{
				int readSize = buffer.Length;

				if ( bytesToCopy < readSize ) {
					readSize = (int)bytesToCopy;
				}

				stream.Position = sourcePosition;
				bytesRead = stream.Read(buffer, 0, readSize);
				if ( bytesRead > 0 ) {
					if ( updateCrc ) {
						crc.Update(buffer, 0, bytesRead);
					}
					stream.Position = destinationPosition;
					stream.Write(buffer, 0, bytesRead);

					destinationPosition += bytesRead;
					sourcePosition += bytesRead;
					bytesToCopy -= bytesRead;
					totalBytesRead += bytesRead;
				}
			}
			while ( (bytesRead > 0) && (bytesToCopy > 0) );

			if ( totalBytesRead != targetBytes ) {
				throw new ZipException(string.Format("Failed to copy bytes expected {0} read {1}", targetBytes, totalBytesRead));
			}

			if ( updateCrc ) {
				update.OutEntry.Crc = crc.Value;
			}
		}
Пример #4
0
		void CopyBytes(ZipUpdate update, Stream destination, Stream source,
			long bytesToCopy, bool updateCrc)
		{
			if ( destination == source ) {
				throw new InvalidOperationException("Destination and source are the same");
			}

			// NOTE: Compressed size is updated elsewhere.
			Crc32 crc = new Crc32();
			byte[] buffer = GetBuffer();

			long targetBytes = bytesToCopy;
			long totalBytesRead = 0;

			int bytesRead;
			do {
				int readSize = buffer.Length;

				if ( bytesToCopy < readSize ) {
					readSize = (int)bytesToCopy;
				}

				bytesRead = source.Read(buffer, 0, readSize);
				if ( bytesRead > 0 ) {
					if ( updateCrc ) {
						crc.Update(buffer, 0, bytesRead);
					}
					destination.Write(buffer, 0, bytesRead);
					bytesToCopy -= bytesRead;
					totalBytesRead += bytesRead;
				}
			}
			while ( (bytesRead > 0) && (bytesToCopy > 0) );

			if ( totalBytesRead != targetBytes ) {
				throw new ZipException(string.Format("Failed to copy bytes expected {0} read {1}", targetBytes, totalBytesRead));
			}

			if ( updateCrc ) {
				update.OutEntry.Crc = crc.Value;
			}
		}
Пример #5
0
 public static int getCRC(string inputString)
 {
     Crc32 crc = new Crc32();
     crc.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(inputString));
     return (int)crc.CrcValue;
 }
Пример #6
0
        protected static UInt32 ComputeFingerprint(byte[] bytes, int length)
        {
            // Length correction is requred like in ComputeMessageIntegrity, but
            // I assume that Fingerprint is last item always. It's true in most cases.

            using (Crc32 crc32 = new Crc32())
            {
                crc32.ComputeHash(bytes, 0, length);

                return crc32.CrcValue ^ 0x5354554e;
            }
        }
Пример #7
0
 public static int CRC(byte[] bytes)
 {
     Crc32 crc32 = new Crc32();
     return BitConverter.ToInt32(crc32.ComputeHash(bytes), 0);
 }