/// <summary>
        /// Read data descriptor at the end of compressed data.
        /// </summary>
        /// <param name="zip64">if set to <c>true</c> [zip64].</param>
        /// <param name="data">The data to fill in.</param>
        /// <returns>Returns the number of bytes read in the descriptor.</returns>
        public void ReadDataDescriptor(bool zip64, DescriptorData data)
        {
            var intValue = ReadLEInt();

            // In theory this may not be a descriptor according to PKZIP appnote.
            // In practise its always there.
            if (intValue != ZipConstants.DataDescriptorSignature)
            {
                throw new ZipException("Data descriptor signature not found");
            }

            data.Crc = ReadLEInt();

            if (zip64)
            {
                data.CompressedSize = ReadLELong();
                data.Size           = ReadLELong();
            }
            else
            {
                data.CompressedSize = ReadLEInt();
                data.Size           = ReadLEInt();
            }
        }
Beispiel #2
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		/// <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");
			}
			
			var status = new TestStatus(this);

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

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

			var testing = true;

			try {
				var 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);
						}

                        var crc = new Crc32();

                        using (var entryStream = GetInputStream(this[entryIndex]))
                        {

                            var 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 ) {
							var helper = new ZipHelperStream(baseStream_);
							var 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);
		}
		/// <summary>
		/// Read data descriptor at the end of compressed data.
		/// </summary>
		/// <param name="zip64">if set to <c>true</c> [zip64].</param>
		/// <param name="data">The data to fill in.</param>
		/// <returns>Returns the number of bytes read in the descriptor.</returns>
		public void ReadDataDescriptor(bool zip64, DescriptorData data)
		{
			var intValue = ReadLEInt();

			// In theory this may not be a descriptor according to PKZIP appnote.
			// In practise its always there.
			if (intValue != ZipConstants.DataDescriptorSignature) {
				throw new ZipException("Data descriptor signature not found");
			}

			data.Crc = ReadLEInt();
			
			if (zip64) {
				data.CompressedSize = ReadLELong();
				data.Size = ReadLELong();
			}
			else {
				data.CompressedSize = ReadLEInt();
				data.Size = ReadLEInt();
			}
		}