wasSharpNET – Blame information for rev 11
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1 | office | 1 | /////////////////////////////////////////////////////////////////////////// |
2 | // Copyright (C) Wizardry and Steamworks 2016 - License: GNU GPLv3 // |
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3 | // Please see: http://www.gnu.org/licenses/gpl.html for legal details, // |
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4 | // rights of fair usage, the disclaimer and warranty conditions. // |
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5 | /////////////////////////////////////////////////////////////////////////// |
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6 | |||
7 | using System; |
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8 | using System.Collections.Generic; |
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9 | using System.IO; |
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10 | using System.Linq; |
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11 | using System.Security.Cryptography; |
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12 | |||
13 | namespace wasSharpNET.Cryptography |
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14 | { |
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15 | public class AES |
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16 | { |
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17 | private const int AES_BLOCK_SIZE = 128; |
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18 | private const CipherMode AES_CIPHER_MODE = CipherMode.CBC; |
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19 | private const PaddingMode AES_PADDING_MODE = PaddingMode.PKCS7; |
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20 | private const int AES_KEY_SALT_BYTES = 16; |
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3 | office | 21 | private static readonly RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider(); |
1 | office | 22 | |
23 | /////////////////////////////////////////////////////////////////////////// |
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24 | // Copyright (C) Wizardry and Steamworks 2016 - License: GNU GPLv3 // |
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25 | /////////////////////////////////////////////////////////////////////////// |
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26 | /// <summary> |
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27 | /// Encrypts a string given a key and initialization vector. |
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28 | /// </summary> |
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29 | /// <param name="data">the string to encrypt</param> |
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30 | /// <param name="key">the encryption key</param> |
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31 | /// <param name="separator">the separator to use between the cyphertext and the IV</param> |
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32 | /// <returns>Base64 encoded encrypted data</returns> |
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33 | public string wasAESEncrypt(string data, string key, string separator = ":") |
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34 | { |
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35 | using (var rijdanelManaged = new RijndaelManaged()) |
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36 | { |
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37 | // FIPS-197 / CBC |
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38 | rijdanelManaged.BlockSize = AES_BLOCK_SIZE; |
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39 | rijdanelManaged.Mode = AES_CIPHER_MODE; |
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40 | rijdanelManaged.Padding = AES_PADDING_MODE; |
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41 | |||
42 | // Compute the salt and the IV from the key. |
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43 | var salt = new byte[AES_KEY_SALT_BYTES]; |
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44 | rng.GetBytes(salt); |
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45 | var derivedKey = new Rfc2898DeriveBytes(key, salt); |
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11 | office | 46 | rijdanelManaged.Key = derivedKey.GetBytes(rijdanelManaged.KeySize / 8); |
47 | rijdanelManaged.IV = derivedKey.GetBytes(rijdanelManaged.BlockSize / 8); |
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1 | office | 48 | |
49 | byte[] encryptedData; |
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50 | using (var encryptor = rijdanelManaged.CreateEncryptor(rijdanelManaged.Key, rijdanelManaged.IV)) |
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51 | { |
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52 | using (var memoryStream = new MemoryStream()) |
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53 | { |
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54 | using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write)) |
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55 | { |
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56 | using (var streamWriter = new StreamWriter(cryptoStream)) |
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57 | { |
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58 | streamWriter.Write(data); |
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59 | } |
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60 | } |
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61 | encryptedData = memoryStream.ToArray(); |
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62 | } |
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63 | } |
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64 | return string.Join(separator, Convert.ToBase64String(salt), Convert.ToBase64String(encryptedData)); |
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65 | } |
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66 | } |
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67 | |||
68 | /////////////////////////////////////////////////////////////////////////// |
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69 | // Copyright (C) Wizardry and Steamworks 2016 - License: GNU GPLv3 // |
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70 | /////////////////////////////////////////////////////////////////////////// |
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71 | /// <summary> |
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72 | /// Decrypts a Base64 encoded string using AES with a given key and initialization vector. |
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73 | /// </summary> |
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74 | /// <param name="data"> |
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75 | /// a string consisting of the cyphertext to decrypt in Base64 and the IV in Base64 separated by the |
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76 | /// separator |
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77 | /// </param> |
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78 | /// <param name="key">the encryption key</param> |
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79 | /// <param name="separator">the separator to use between the cyphertext and the IV</param> |
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80 | /// <returns>the decrypted data</returns> |
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81 | public string wasAESDecrypt(string data, string key, string separator = ":") |
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82 | { |
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83 | // retrieve the salt from the data. |
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11 | office | 84 | var segments = new List<string>(data.Split(new[] { separator }, StringSplitOptions.None)); |
1 | office | 85 | if (!segments.Count.Equals(2)) |
86 | throw new ArgumentException("Invalid data."); |
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87 | |||
88 | string plaintext; |
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89 | using (var rijdanelManaged = new RijndaelManaged()) |
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90 | { |
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91 | // FIPS-197 / CBC |
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92 | rijdanelManaged.BlockSize = AES_BLOCK_SIZE; |
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93 | rijdanelManaged.Mode = AES_CIPHER_MODE; |
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94 | rijdanelManaged.Padding = AES_PADDING_MODE; |
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95 | |||
96 | // Retrieve the key and the IV from the salt. |
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97 | var derivedKey = new Rfc2898DeriveBytes(key, Convert.FromBase64String(segments.First().Trim())); |
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11 | office | 98 | rijdanelManaged.Key = derivedKey.GetBytes(rijdanelManaged.KeySize / 8); |
99 | rijdanelManaged.IV = derivedKey.GetBytes(rijdanelManaged.BlockSize / 8); |
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1 | office | 100 | |
101 | using (var decryptor = rijdanelManaged.CreateDecryptor(rijdanelManaged.Key, rijdanelManaged.IV)) |
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102 | { |
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103 | using (var memoryStream = new MemoryStream(Convert.FromBase64String(segments.Last().Trim()))) |
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104 | { |
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105 | using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read)) |
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106 | { |
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107 | using (var streamReader = new StreamReader(cryptoStream)) |
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108 | { |
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109 | plaintext = streamReader.ReadToEnd(); |
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110 | } |
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111 | } |
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112 | } |
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113 | } |
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114 | } |
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115 | return plaintext; |
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116 | } |
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117 | } |
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11 | office | 118 | } |