ICSharpCode.SharpZipLib.Encryption.PkzipClassicDecryptCryptoTransform - Coverage Report

# Summary

Class: | ICSharpCode.SharpZipLib.Encryption.PkzipClassicDecryptCryptoTransform
Assembly: | ICSharpCode.SharpZipLib
File(s): | C:\Users\Neil\Documents\Visual Studio 2015\Projects\icsharpcode\SZL_master\ICSharpCode.SharpZipLib\Encryption\PkzipClassic.cs
Covered lines: | 14
Uncovered lines: | 3
Coverable lines: | 17
Total lines: | 445
Line coverage: | 82.3%
Branch coverage: | 100%

# Metrics

Method | Cyclomatic Complexity | Sequence Coverage | Branch Coverage
--- | --- | --- | ---
.ctor(...) | 1 | 100 | 100
TransformFinalBlock(...) | 1 | 100 | 100
TransformBlock(...) | 2 | 100 | 100
Dispose() | 1 | 0 | 0

# File(s)

## C:\Users\Neil\Documents\Visual Studio 2015\Projects\icsharpcode\SZL_master\ICSharpCode.SharpZipLib\Encryption\PkzipClassic.cs

| # | Line |  | Line coverage
--- | --- | --- | --- | ---
|  | `1` |  | `using System;`
|  | `2` |  | `using System.Security.Cryptography;`
|  | `3` |  | `using ICSharpCode.SharpZipLib.Checksum;`
|  | `4` |  | ``
|  | `5` |  | `namespace ICSharpCode.SharpZipLib.Encryption`
|  | `6` |  | `{`
|  | `7` |  | `/// <summary>`
|  | `8` |  | `/// PkzipClassic embodies the classic or original encryption facilities used in Pkzip archives.`
|  | `9` |  | `/// While it has been superceded by more recent and more powerful algorithms, its still in use and`
|  | `10` |  | `/// is viable for preventing casual snooping`
|  | `11` |  | `/// </summary>`
|  | `12` |  | `public abstract class PkzipClassic : SymmetricAlgorithm`
|  | `13` |  | `{`
|  | `14` |  | `/// <summary>`
|  | `15` |  | `/// Generates new encryption keys based on given seed`
|  | `16` |  | `/// </summary>`
|  | `17` |  | `/// <param name="seed">The seed value to initialise keys with.</param>`
|  | `18` |  | `/// <returns>A new key value.</returns>`
|  | `19` |  | `static public byte[] GenerateKeys(byte[] seed)`
|  | `20` |  | `{`
|  | `21` |  | `if (seed == null) {`
|  | `22` |  | `throw new ArgumentNullException(nameof(seed));`
|  | `23` |  | `}`
|  | `24` |  | ``
|  | `25` |  | `if (seed.Length == 0) {`
|  | `26` |  | `throw new ArgumentException("Length is zero", nameof(seed));`
|  | `27` |  | `}`
|  | `28` |  | ``
|  | `29` |  | `uint[] newKeys = {`
|  | `30` |  | `0x12345678,`
|  | `31` |  | `0x23456789,`
|  | `32` |  | `0x34567890`
|  | `33` |  | `};`
|  | `34` |  | ``
|  | `35` |  | `for (int i = 0; i < seed.Length; ++i) {`
|  | `36` |  | `newKeys[0] = Crc32.ComputeCrc32(newKeys[0], seed[i]);`
|  | `37` |  | `newKeys[1] = newKeys[1] + (byte)newKeys[0];`
|  | `38` |  | `newKeys[1] = newKeys[1] * 134775813 + 1;`
|  | `39` |  | `newKeys[2] = Crc32.ComputeCrc32(newKeys[2], (byte)(newKeys[1] >> 24));`
|  | `40` |  | `}`
|  | `41` |  | ``
|  | `42` |  | `byte[] result = new byte[12];`
|  | `43` |  | `result[0] = (byte)(newKeys[0] & 0xff);`
|  | `44` |  | `result[1] = (byte)((newKeys[0] >> 8) & 0xff);`
|  | `45` |  | `result[2] = (byte)((newKeys[0] >> 16) & 0xff);`
|  | `46` |  | `result[3] = (byte)((newKeys[0] >> 24) & 0xff);`
|  | `47` |  | `result[4] = (byte)(newKeys[1] & 0xff);`
|  | `48` |  | `result[5] = (byte)((newKeys[1] >> 8) & 0xff);`
|  | `49` |  | `result[6] = (byte)((newKeys[1] >> 16) & 0xff);`
|  | `50` |  | `result[7] = (byte)((newKeys[1] >> 24) & 0xff);`
|  | `51` |  | `result[8] = (byte)(newKeys[2] & 0xff);`
|  | `52` |  | `result[9] = (byte)((newKeys[2] >> 8) & 0xff);`
|  | `53` |  | `result[10] = (byte)((newKeys[2] >> 16) & 0xff);`
|  | `54` |  | `result[11] = (byte)((newKeys[2] >> 24) & 0xff);`
|  | `55` |  | `return result;`
|  | `56` |  | `}`
|  | `57` |  | `}`
|  | `58` |  | ``
|  | `59` |  | `/// <summary>`
|  | `60` |  | `/// PkzipClassicCryptoBase provides the low level facilities for encryption`
|  | `61` |  | `/// and decryption using the PkzipClassic algorithm.`
|  | `62` |  | `/// </summary>`
|  | `63` |  | `class PkzipClassicCryptoBase`
|  | `64` |  | `{`
|  | `65` |  | `/// <summary>`
|  | `66` |  | `/// Transform a single byte`
|  | `67` |  | `/// </summary>`
|  | `68` |  | `/// <returns>`
|  | `69` |  | `/// The transformed value`
|  | `70` |  | `/// </returns>`
|  | `71` |  | `protected byte TransformByte()`
|  | `72` |  | `{`
|  | `73` |  | `uint temp = ((keys[2] & 0xFFFF) | 2);`
|  | `74` |  | `return (byte)((temp * (temp ^ 1)) >> 8);`
|  | `75` |  | `}`
|  | `76` |  | ``
|  | `77` |  | `/// <summary>`
|  | `78` |  | `/// Set the key schedule for encryption/decryption.`
|  | `79` |  | `/// </summary>`
|  | `80` |  | `/// <param name="keyData">The data use to set the keys from.</param>`
|  | `81` |  | `protected void SetKeys(byte[] keyData)`
|  | `82` |  | `{`
|  | `83` |  | `if (keyData == null) {`
|  | `84` |  | `throw new ArgumentNullException(nameof(keyData));`
|  | `85` |  | `}`
|  | `86` |  | ``
|  | `87` |  | `if (keyData.Length != 12) {`
|  | `88` |  | `throw new InvalidOperationException("Key length is not valid");`
|  | `89` |  | `}`
|  | `90` |  | ``
|  | `91` |  | `keys = new uint[3];`
|  | `92` |  | `keys[0] = (uint)((keyData[3] << 24) | (keyData[2] << 16) | (keyData[1] << 8) | keyData[0]);`
|  | `93` |  | `keys[1] = (uint)((keyData[7] << 24) | (keyData[6] << 16) | (keyData[5] << 8) | keyData[4]);`
|  | `94` |  | `keys[2] = (uint)((keyData[11] << 24) | (keyData[10] << 16) | (keyData[9] << 8) | keyData[8]);`
|  | `95` |  | `}`
|  | `96` |  | ``
|  | `97` |  | `/// <summary>`
|  | `98` |  | `/// Update encryption keys`
|  | `99` |  | `/// </summary>`
|  | `100` |  | `protected void UpdateKeys(byte ch)`
|  | `101` |  | `{`
|  | `102` |  | `keys[0] = Crc32.ComputeCrc32(keys[0], ch);`
|  | `103` |  | `keys[1] = keys[1] + (byte)keys[0];`
|  | `104` |  | `keys[1] = keys[1] * 134775813 + 1;`
|  | `105` |  | `keys[2] = Crc32.ComputeCrc32(keys[2], (byte)(keys[1] >> 24));`
|  | `106` |  | `}`
|  | `107` |  | ``
|  | `108` |  | `/// <summary>`
|  | `109` |  | `/// Reset the internal state.`
|  | `110` |  | `/// </summary>`
|  | `111` |  | `protected void Reset()`
|  | `112` |  | `{`
|  | `113` |  | `keys[0] = 0;`
|  | `114` |  | `keys[1] = 0;`
|  | `115` |  | `keys[2] = 0;`
|  | `116` |  | `}`
|  | `117` |  | ``
|  | `118` |  | `#region Instance Fields`
|  | `119` |  | `uint[] keys;`
|  | `120` |  | `#endregion`
|  | `121` |  | `}`
|  | `122` |  | ``
|  | `123` |  | `/// <summary>`
|  | `124` |  | `/// PkzipClassic CryptoTransform for encryption.`
|  | `125` |  | `/// </summary>`
|  | `126` |  | `class PkzipClassicEncryptCryptoTransform : PkzipClassicCryptoBase, ICryptoTransform`
|  | `127` |  | `{`
|  | `128` |  | `/// <summary>`
|  | `129` |  | `/// Initialise a new instance of <see cref="PkzipClassicEncryptCryptoTransform"></see>`
|  | `130` |  | `/// </summary>`
|  | `131` |  | `/// <param name="keyBlock">The key block to use.</param>`
|  | `132` |  | `internal PkzipClassicEncryptCryptoTransform(byte[] keyBlock)`
|  | `133` |  | `{`
|  | `134` |  | `SetKeys(keyBlock);`
|  | `135` |  | `}`
|  | `136` |  | ``
|  | `137` |  | `#region ICryptoTransform Members`
|  | `138` |  | ``
|  | `139` |  | `/// <summary>`
|  | `140` |  | `/// Transforms the specified region of the specified byte array.`
|  | `141` |  | `/// </summary>`
|  | `142` |  | `/// <param name="inputBuffer">The input for which to compute the transform.</param>`
|  | `143` |  | `/// <param name="inputOffset">The offset into the byte array from which to begin using data.</param>`
|  | `144` |  | `/// <param name="inputCount">The number of bytes in the byte array to use as data.</param>`
|  | `145` |  | `/// <returns>The computed transform.</returns>`
|  | `146` |  | `public byte[] TransformFinalBlock(byte[] inputBuffer, int inputOffset, int inputCount)`
|  | `147` |  | `{`
|  | `148` |  | `byte[] result = new byte[inputCount];`
|  | `149` |  | `TransformBlock(inputBuffer, inputOffset, inputCount, result, 0);`
|  | `150` |  | `return result;`
|  | `151` |  | `}`
|  | `152` |  | ``
|  | `153` |  | `/// <summary>`
|  | `154` |  | `/// Transforms the specified region of the input byte array and copies`
|  | `155` |  | `/// the resulting transform to the specified region of the output byte array.`
|  | `156` |  | `/// </summary>`
|  | `157` |  | `/// <param name="inputBuffer">The input for which to compute the transform.</param>`
|  | `158` |  | `/// <param name="inputOffset">The offset into the input byte array from which to begin using data.</param>`
|  | `159` |  | `/// <param name="inputCount">The number of bytes in the input byte array to use as data.</param>`
|  | `160` |  | `/// <param name="outputBuffer">The output to which to write the transform.</param>`
|  | `161` |  | `/// <param name="outputOffset">The offset into the output byte array from which to begin writing data.</param>`
|  | `162` |  | `/// <returns>The number of bytes written.</returns>`
|  | `163` |  | `public int TransformBlock(byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset`
|  | `164` |  | `{`
|  | `165` |  | `for (int i = inputOffset; i < inputOffset + inputCount; ++i) {`
|  | `166` |  | `byte oldbyte = inputBuffer[i];`
|  | `167` |  | `outputBuffer[outputOffset++] = (byte)(inputBuffer[i] ^ TransformByte());`
|  | `168` |  | `UpdateKeys(oldbyte);`
|  | `169` |  | `}`
|  | `170` |  | `return inputCount;`
|  | `171` |  | `}`
|  | `172` |  | ``
|  | `173` |  | `/// <summary>`
|  | `174` |  | `/// Gets a value indicating whether the current transform can be reused.`
|  | `175` |  | `/// </summary>`
|  | `176` |  | `public bool CanReuseTransform {`
|  | `177` |  | `get {`
|  | `178` |  | `return true;`
|  | `179` |  | `}`
|  | `180` |  | `}`
|  | `181` |  | ``
|  | `182` |  | `/// <summary>`
|  | `183` |  | `/// Gets the size of the input data blocks in bytes.`
|  | `184` |  | `/// </summary>`
|  | `185` |  | `public int InputBlockSize {`
|  | `186` |  | `get {`
|  | `187` |  | `return 1;`
|  | `188` |  | `}`
|  | `189` |  | `}`
|  | `190` |  | ``
|  | `191` |  | `/// <summary>`
|  | `192` |  | `/// Gets the size of the output data blocks in bytes.`
|  | `193` |  | `/// </summary>`
|  | `194` |  | `public int OutputBlockSize {`
|  | `195` |  | `get {`
|  | `196` |  | `return 1;`
|  | `197` |  | `}`
|  | `198` |  | `}`
|  | `199` |  | ``
|  | `200` |  | `/// <summary>`
|  | `201` |  | `/// Gets a value indicating whether multiple blocks can be transformed.`
|  | `202` |  | `/// </summary>`
|  | `203` |  | `public bool CanTransformMultipleBlocks {`
|  | `204` |  | `get {`
|  | `205` |  | `return true;`
|  | `206` |  | `}`
|  | `207` |  | `}`
|  | `208` |  | ``
|  | `209` |  | `#endregion`
|  | `210` |  | ``
|  | `211` |  | `#region IDisposable Members`
|  | `212` |  | ``
|  | `213` |  | `/// <summary>`
|  | `214` |  | `/// Cleanup internal state.`
|  | `215` |  | `/// </summary>`
|  | `216` |  | `public void Dispose()`
|  | `217` |  | `{`
|  | `218` |  | `Reset();`
|  | `219` |  | `}`
|  | `220` |  | ``
|  | `221` |  | `#endregion`
|  | `222` |  | `}`
|  | `223` |  | ``
|  | `224` |  | ``
|  | `225` |  | `/// <summary>`
|  | `226` |  | `/// PkzipClassic CryptoTransform for decryption.`
|  | `227` |  | `/// </summary>`
|  | `228` |  | `class PkzipClassicDecryptCryptoTransform : PkzipClassicCryptoBase, ICryptoTransform`
|  | `229` |  | `{`
|  | `230` |  | `/// <summary>`
|  | `231` |  | `/// Initialise a new instance of <see cref="PkzipClassicDecryptCryptoTransform"></see>.`
|  | `232` |  | `/// </summary>`
|  | `233` |  | `/// <param name="keyBlock">The key block to decrypt with.</param>`
| 34 | `234` |  | `internal PkzipClassicDecryptCryptoTransform(byte[] keyBlock)`
|  | `235` |  | `{`
| 34 | `236` |  | `SetKeys(keyBlock);`
| 34 | `237` |  | `}`
|  | `238` |  | ``
|  | `239` |  | `#region ICryptoTransform Members`
|  | `240` |  | ``
|  | `241` |  | `/// <summary>`
|  | `242` |  | `/// Transforms the specified region of the specified byte array.`
|  | `243` |  | `/// </summary>`
|  | `244` |  | `/// <param name="inputBuffer">The input for which to compute the transform.</param>`
|  | `245` |  | `/// <param name="inputOffset">The offset into the byte array from which to begin using data.</param>`
|  | `246` |  | `/// <param name="inputCount">The number of bytes in the byte array to use as data.</param>`
|  | `247` |  | `/// <returns>The computed transform.</returns>`
|  | `248` |  | `public byte[] TransformFinalBlock(byte[] inputBuffer, int inputOffset, int inputCount)`
|  | `249` |  | `{`
| 10 | `250` |  | `byte[] result = new byte[inputCount];`
| 10 | `251` |  | `TransformBlock(inputBuffer, inputOffset, inputCount, result, 0);`
| 10 | `252` |  | `return result;`
|  | `253` |  | `}`
|  | `254` |  | ``
|  | `255` |  | `/// <summary>`
|  | `256` |  | `/// Transforms the specified region of the input byte array and copies`
|  | `257` |  | `/// the resulting transform to the specified region of the output byte array.`
|  | `258` |  | `/// </summary>`
|  | `259` |  | `/// <param name="inputBuffer">The input for which to compute the transform.</param>`
|  | `260` |  | `/// <param name="inputOffset">The offset into the input byte array from which to begin using data.</param>`
|  | `261` |  | `/// <param name="inputCount">The number of bytes in the input byte array to use as data.</param>`
|  | `262` |  | `/// <param name="outputBuffer">The output to which to write the transform.</param>`
|  | `263` |  | `/// <param name="outputOffset">The offset into the output byte array from which to begin writing data.</param>`
|  | `264` |  | `/// <returns>The number of bytes written.</returns>`
|  | `265` |  | `public int TransformBlock(byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset`
|  | `266` |  | `{`
| 2262036 | `267` |  | `for (int i = inputOffset; i < inputOffset + inputCount; ++i) {`
| 1130694 | `268` |  | `var newByte = (byte)(inputBuffer[i] ^ TransformByte());`
| 1130694 | `269` |  | `outputBuffer[outputOffset++] = newByte;`
| 1130694 | `270` |  | `UpdateKeys(newByte);`
|  | `271` |  | `}`
| 324 | `272` |  | `return inputCount;`
|  | `273` |  | `}`
|  | `274` |  | ``
|  | `275` |  | `/// <summary>`
|  | `276` |  | `/// Gets a value indicating whether the current transform can be reused.`
|  | `277` |  | `/// </summary>`
|  | `278` |  | `public bool CanReuseTransform {`
|  | `279` |  | `get {`
| 0 | `280` |  | `return true;`
|  | `281` |  | `}`
|  | `282` |  | `}`
|  | `283` |  | ``
|  | `284` |  | `/// <summary>`
|  | `285` |  | `/// Gets the size of the input data blocks in bytes.`
|  | `286` |  | `/// </summary>`
|  | `287` |  | `public int InputBlockSize {`
|  | `288` |  | `get {`
| 10 | `289` |  | `return 1;`
|  | `290` |  | `}`
|  | `291` |  | `}`
|  | `292` |  | ``
|  | `293` |  | `/// <summary>`
|  | `294` |  | `/// Gets the size of the output data blocks in bytes.`
|  | `295` |  | `/// </summary>`
|  | `296` |  | `public int OutputBlockSize {`
|  | `297` |  | `get {`
| 10 | `298` |  | `return 1;`
|  | `299` |  | `}`
|  | `300` |  | `}`
|  | `301` |  | ``
|  | `302` |  | `/// <summary>`
|  | `303` |  | `/// Gets a value indicating whether multiple blocks can be transformed.`
|  | `304` |  | `/// </summary>`
|  | `305` |  | `public bool CanTransformMultipleBlocks {`
|  | `306` |  | `get {`
| 26 | `307` |  | `return true;`
|  | `308` |  | `}`
|  | `309` |  | `}`
|  | `310` |  | ``
|  | `311` |  | `#endregion`
|  | `312` |  | ``
|  | `313` |  | `#region IDisposable Members`
|  | `314` |  | ``
|  | `315` |  | `/// <summary>`
|  | `316` |  | `/// Cleanup internal state.`
|  | `317` |  | `/// </summary>`
|  | `318` |  | `public void Dispose()`
|  | `319` |  | `{`
| 0 | `320` |  | `Reset();`
| 0 | `321` |  | `}`
|  | `322` |  | ``
|  | `323` |  | `#endregion`
|  | `324` |  | `}`
|  | `325` |  | ``
|  | `326` |  | `/// <summary>`
|  | `327` |  | `/// Defines a wrapper object to access the Pkzip algorithm.`
|  | `328` |  | `/// This class cannot be inherited.`
|  | `329` |  | `/// </summary>`
|  | `330` |  | `public sealed class PkzipClassicManaged : PkzipClassic`
|  | `331` |  | `{`
|  | `332` |  | `/// <summary>`
|  | `333` |  | `/// Get / set the applicable block size in bits.`
|  | `334` |  | `/// </summary>`
|  | `335` |  | `/// <remarks>The only valid block size is 8.</remarks>`
|  | `336` |  | `public override int BlockSize {`
|  | `337` |  | `get {`
|  | `338` |  | `return 8;`
|  | `339` |  | `}`
|  | `340` |  | ``
|  | `341` |  | `set {`
|  | `342` |  | `if (value != 8) {`
|  | `343` |  | `throw new CryptographicException("Block size is invalid");`
|  | `344` |  | `}`
|  | `345` |  | `}`
|  | `346` |  | `}`
|  | `347` |  | ``
|  | `348` |  | `/// <summary>`
|  | `349` |  | `/// Get an array of legal <see cref="KeySizes">key sizes.</see>`
|  | `350` |  | `/// </summary>`
|  | `351` |  | `public override KeySizes[] LegalKeySizes {`
|  | `352` |  | `get {`
|  | `353` |  | `KeySizes[] keySizes = new KeySizes[1];`
|  | `354` |  | `keySizes[0] = new KeySizes(12 * 8, 12 * 8, 0);`
|  | `355` |  | `return keySizes;`
|  | `356` |  | `}`
|  | `357` |  | `}`
|  | `358` |  | ``
|  | `359` |  | `/// <summary>`
|  | `360` |  | `/// Generate an initial vector.`
|  | `361` |  | `/// </summary>`
|  | `362` |  | `public override void GenerateIV()`
|  | `363` |  | `{`
|  | `364` |  | `// Do nothing.`
|  | `365` |  | `}`
|  | `366` |  | ``
|  | `367` |  | `/// <summary>`
|  | `368` |  | `/// Get an array of legal <see cref="KeySizes">block sizes</see>.`
|  | `369` |  | `/// </summary>`
|  | `370` |  | `public override KeySizes[] LegalBlockSizes {`
|  | `371` |  | `get {`
|  | `372` |  | `KeySizes[] keySizes = new KeySizes[1];`
|  | `373` |  | `keySizes[0] = new KeySizes(1 * 8, 1 * 8, 0);`
|  | `374` |  | `return keySizes;`
|  | `375` |  | `}`
|  | `376` |  | `}`
|  | `377` |  | ``
|  | `378` |  | `/// <summary>`
|  | `379` |  | `/// Get / set the key value applicable.`
|  | `380` |  | `/// </summary>`
|  | `381` |  | `public override byte[] Key {`
|  | `382` |  | `get {`
|  | `383` |  | `if (key_ == null) {`
|  | `384` |  | `GenerateKey();`
|  | `385` |  | `}`
|  | `386` |  | ``
|  | `387` |  | `return (byte[])key_.Clone();`
|  | `388` |  | `}`
|  | `389` |  | ``
|  | `390` |  | `set {`
|  | `391` |  | `if (value == null) {`
|  | `392` |  | `throw new ArgumentNullException(nameof(value));`
|  | `393` |  | `}`
|  | `394` |  | ``
|  | `395` |  | `if (value.Length != 12) {`
|  | `396` |  | `throw new CryptographicException("Key size is illegal");`
|  | `397` |  | `}`
|  | `398` |  | ``
|  | `399` |  | `key_ = (byte[])value.Clone();`
|  | `400` |  | `}`
|  | `401` |  | `}`
|  | `402` |  | ``
|  | `403` |  | `/// <summary>`
|  | `404` |  | `/// Generate a new random key.`
|  | `405` |  | `/// </summary>`
|  | `406` |  | `public override void GenerateKey()`
|  | `407` |  | `{`
|  | `408` |  | `key_ = new byte[12];`
|  | `409` |  | `var rnd = new Random();`
|  | `410` |  | `rnd.NextBytes(key_);`
|  | `411` |  | `}`
|  | `412` |  | ``
|  | `413` |  | `/// <summary>`
|  | `414` |  | `/// Create an encryptor.`
|  | `415` |  | `/// </summary>`
|  | `416` |  | `/// <param name="rgbKey">The key to use for this encryptor.</param>`
|  | `417` |  | `/// <param name="rgbIV">Initialisation vector for the new encryptor.</param>`
|  | `418` |  | `/// <returns>Returns a new PkzipClassic encryptor</returns>`
|  | `419` |  | `public override ICryptoTransform CreateEncryptor(`
|  | `420` |  | `byte[] rgbKey,`
|  | `421` |  | `byte[] rgbIV)`
|  | `422` |  | `{`
|  | `423` |  | `key_ = rgbKey;`
|  | `424` |  | `return new PkzipClassicEncryptCryptoTransform(Key);`
|  | `425` |  | `}`
|  | `426` |  | ``
|  | `427` |  | `/// <summary>`
|  | `428` |  | `/// Create a decryptor.`
|  | `429` |  | `/// </summary>`
|  | `430` |  | `/// <param name="rgbKey">Keys to use for this new decryptor.</param>`
|  | `431` |  | `/// <param name="rgbIV">Initialisation vector for the new decryptor.</param>`
|  | `432` |  | `/// <returns>Returns a new decryptor.</returns>`
|  | `433` |  | `public override ICryptoTransform CreateDecryptor(`
|  | `434` |  | `byte[] rgbKey,`
|  | `435` |  | `byte[] rgbIV)`
|  | `436` |  | `{`
|  | `437` |  | `key_ = rgbKey;`
|  | `438` |  | `return new PkzipClassicDecryptCryptoTransform(Key);`
|  | `439` |  | `}`
|  | `440` |  | ``
|  | `441` |  | `#region Instance Fields`
|  | `442` |  | `byte[] key_;`
|  | `443` |  | `#endregion`
|  | `444` |  | `}`
|  | `445` |  | `}`