public RuntimeInfo(CompressionMethod method, int compressionLevel, int size, string password, bool getCrc) { this.method = method; this.compressionLevel = compressionLevel; this.password = password; this.size = size; random = false; original = new byte[Size]; if (random) { var rnd = new Random(); rnd.NextBytes(original); } else { for (var i = 0; i < size; ++i) { original[i] = (byte) 'A'; } } if (getCrc) { var crc32 = new Crc32(); crc32.Update(original, 0, size); crc = crc32.Value; } }
private void ReadHeader() { // 1. Check the two magic bytes var headCRC = new Crc32(); var magic = baseInputStream.ReadByte(); if (magic < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } headCRC.Update(magic); if (magic != (GZipConstants.GZIP_MAGIC >> 8)) { throw new GZipException("Error GZIP header, first magic byte doesn't match"); } magic = baseInputStream.ReadByte(); if (magic < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } if (magic != (GZipConstants.GZIP_MAGIC & 0xFF)) { throw new GZipException("Error GZIP header, second magic byte doesn't match"); } headCRC.Update(magic); // 2. Check the compression type (must be 8) var compressionType = baseInputStream.ReadByte(); if (compressionType < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } if (compressionType != 8) { throw new GZipException("Error GZIP header, data not in deflate format"); } headCRC.Update(compressionType); // 3. Check the flags var flags = baseInputStream.ReadByte(); if (flags < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } headCRC.Update(flags); /* This flag byte is divided into individual bits as follows: bit 0 FTEXT bit 1 FHCRC bit 2 FEXTRA bit 3 FNAME bit 4 FCOMMENT bit 5 reserved bit 6 reserved bit 7 reserved */ // 3.1 Check the reserved bits are zero if ((flags & 0xd0) != 0) { throw new GZipException("Reserved flag bits in GZIP header != 0"); } // 4.-6. Skip the modification time, extra flags, and OS type for (var i = 0; i < 6; i++) { var readByte = baseInputStream.ReadByte(); if (readByte < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } headCRC.Update(readByte); } // 7. Read extra field if ((flags & GZipConstants.FEXTRA) != 0) { // Skip subfield id for (var i = 0; i < 2; i++) { var readByte = baseInputStream.ReadByte(); if (readByte < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } headCRC.Update(readByte); } if (baseInputStream.ReadByte() < 0 || baseInputStream.ReadByte() < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } var len1 = baseInputStream.ReadByte(); var len2 = baseInputStream.ReadByte(); if ((len1 < 0) || (len2 < 0)) { throw new EndOfStreamException("EOS reading GZIP header"); } headCRC.Update(len1); headCRC.Update(len2); var extraLen = (len1 << 8) | len2; for (var i = 0; i < extraLen; i++) { var readByte = baseInputStream.ReadByte(); if (readByte < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } headCRC.Update(readByte); } } // 8. Read file name if ((flags & GZipConstants.FNAME) != 0) { int readByte; while ((readByte = baseInputStream.ReadByte()) > 0) { headCRC.Update(readByte); } if (readByte < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } headCRC.Update(readByte); } // 9. Read comment if ((flags & GZipConstants.FCOMMENT) != 0) { int readByte; while ((readByte = baseInputStream.ReadByte()) > 0) { headCRC.Update(readByte); } if (readByte < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } headCRC.Update(readByte); } // 10. Read header CRC if ((flags & GZipConstants.FHCRC) != 0) { var crcval = baseInputStream.ReadByte(); if (crcval < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } int tempByte = baseInputStream.ReadByte(); if (tempByte < 0) { throw new EndOfStreamException("EOS reading GZIP header"); } crcval = (crcval << 8) | tempByte; if (crcval != ((int) headCRC.Value & 0xffff)) { throw new GZipException("Header CRC value mismatch"); } } readGZIPHeader = true; }
/// <summary> /// Closes the zip input stream /// </summary> public override void Close() { internalReader = ReadingNotAvailable; crc = null; entry = null; base.Close(); }