Esempio n. 1
0
		/// <summary>
		/// Perform the initial read on an entry which may include 
		/// reading encryption headers and setting up inflation.
		/// </summary>
		/// <param name="destination">The destination to fill with data read.</param>
		/// <param name="offset">The offset to start reading at.</param>
		/// <param name="count">The maximum number of bytes to read.</param>
		/// <returns>The actual number of bytes read.</returns>
		int InitialRead(byte[] destination, int offset, int count)
		{
			if ( !CanDecompressEntry ) {
				throw new ZipException("Library cannot extract this entry. Version required is (" + entry.Version.ToString() + ")");
			}
			
			// Handle encryption if required.
			if (entry.IsCrypted) {
#if NETCF_1_0
				throw new ZipException("Encryption not supported for Compact Framework 1.0");
#else
				if (password == null) {
					throw new ZipException("No password set.");
				}
				
				// Generate and set crypto transform...
				PkzipClassicManaged managed = new PkzipClassicManaged();
				byte[] key = PkzipClassic.GenerateKeys(ZipConstants.ConvertToArray(password));
				
				inputBuffer.CryptoTransform = managed.CreateDecryptor(key, null);
				
				byte[] cryptbuffer = new byte[ZipConstants.CryptoHeaderSize];
				inputBuffer.ReadClearTextBuffer(cryptbuffer, 0, ZipConstants.CryptoHeaderSize);

				if (cryptbuffer[ZipConstants.CryptoHeaderSize - 1] != entry.CryptoCheckValue) {
					throw new ZipException("Invalid password");
				}

				if (csize >= ZipConstants.CryptoHeaderSize) {
					csize -= ZipConstants.CryptoHeaderSize;
				}
				else if ( (entry.Flags & (int)GeneralBitFlags.Descriptor) == 0 ) {
					throw new ZipException(string.Format("Entry compressed size {0} too small for encryption", csize));
				}
#endif				
			} else {
#if !NETCF_1_0
				inputBuffer.CryptoTransform = null;
#endif				
			}

			if ((csize > 0) || ((flags & (int)GeneralBitFlags.Descriptor) != 0)) {
				if ((method == (int)CompressionMethod.Deflated) && (inputBuffer.Available > 0)) {
					inputBuffer.SetInflaterInput(inf);
				}

				internalReader = new ReadDataHandler(BodyRead);
				return BodyRead(destination, offset, count);
			}
			else {
				internalReader = new ReadDataHandler(ReadingNotAvailable);
				return 0;
			}
		}
Esempio n. 2
0
		Stream CreateAndInitEncryptionStream(Stream baseStream, ZipEntry entry)
		{
			CryptoStream result = null;
			if ( (entry.Version < ZipConstants.VersionStrongEncryption)
				|| (entry.Flags & (int)GeneralBitFlags.StrongEncryption) == 0) {
				PkzipClassicManaged classicManaged = new PkzipClassicManaged();

				OnKeysRequired(entry.Name);
				if (HaveKeys == false) {
					throw new ZipException("No password available for encrypted stream");
				}

				// Closing a CryptoStream will close the base stream as well so wrap it in an UncompressedStream
				// which doesnt do this.
				result = new CryptoStream(new UncompressedStream(baseStream),
					classicManaged.CreateEncryptor(key, null), CryptoStreamMode.Write);

				if ( (entry.Crc < 0) || (entry.Flags & 8) != 0) {
					WriteEncryptionHeader(result, entry.DosTime << 16);
				}
				else {
					WriteEncryptionHeader(result, entry.Crc);
				}
			}
			return result;
		}
Esempio n. 3
0
File: Cipher.cs Progetto: avs009/gsf
        /// <summary>
        /// Returns a binary array of decrypted data for the given parameters.
        /// </summary>
        public static byte[] Decrypt(this byte[] source, int startIndex, int length, byte[] key, byte[] IV, CipherStrength strength)
        {
            if (strength == CipherStrength.None)
                return source;

            // Performs requested levels of decryption.
            if (strength >= CipherStrength.Level6)
            {
                source = new Pkzip.PkzipClassicManaged().Decrypt(source, startIndex, length, key, IV);
                startIndex = 0;
                length = source.Length;
            }

            if (strength >= CipherStrength.Level5)
            {
                source = Deobfuscate(source, startIndex, length, key);
                startIndex = 0;
                length = source.Length;
            }

            if (strength >= CipherStrength.Level4)
            {
                source = new RijndaelManaged().Decrypt(source, startIndex, length, key, IV);
                startIndex = 0;
                length = source.Length;
            }

            if (strength >= CipherStrength.Level3)
            {
                source = new RC2CryptoServiceProvider().Decrypt(source, startIndex, length, key, IV);
                startIndex = 0;
                length = source.Length;
            }

            if (strength >= CipherStrength.Level2)
            {
                source = new TripleDESCryptoServiceProvider().Decrypt(source, startIndex, length, key, IV);
                startIndex = 0;
                length = source.Length;
            }

            return Crypt(source, startIndex, length, key);
        }
Esempio n. 4
0
		Stream CreateAndInitDecryptionStream(Stream baseStream, ZipEntry entry)
		{
			CryptoStream result = null;

			if ( (entry.Version < ZipConstants.VersionStrongEncryption)
				|| (entry.Flags & (int)GeneralBitFlags.StrongEncryption) == 0) {
				PkzipClassicManaged classicManaged = new PkzipClassicManaged();

				OnKeysRequired(entry.Name);
				if (HaveKeys == false) {
					throw new ZipException("No password available for encrypted stream");
				}

				result = new CryptoStream(baseStream, classicManaged.CreateDecryptor(key, null), CryptoStreamMode.Read);
				CheckClassicPassword(result, entry);
			}
			else {
				throw new ZipException("Decryption method not supported");
			}

			return result;
		}
Esempio n. 5
0
		/// <summary>
		/// Initializes encryption keys based on given <paramref name="password"/>.
		/// </summary>
		/// <param name="password">The password.</param>
		protected void InitializePassword(string password)
		{
#if NETCF_1_0
			keys = new uint[] {
				0x12345678,
				0x23456789,
				0x34567890
			};
			
			byte[] rawPassword = ZipConstants.ConvertToArray(password);
			
			for (int i = 0; i < rawPassword.Length; ++i) {
				UpdateKeys((byte)rawPassword[i]);
			}
			
#else			
			PkzipClassicManaged pkManaged = new PkzipClassicManaged();
			byte[] key = PkzipClassic.GenerateKeys(ZipConstants.ConvertToArray(password));
			cryptoTransform_ = pkManaged.CreateEncryptor(key, null);
#endif
		}