na-get-lib/NaGet.Packages/HashValue.cs

   1 using System;\r
   2 using System.IO;\r
   3 using System.Xml.Serialization;\r
   4 using System.Security.Cryptography;\r
   5 \r
   6 namespace NaGet.Packages\r
   7 {\r
   8         /// <summary>\r
   9         /// ハッシュ値の種類(計算法)を表す。\r
  10         /// </summary>\r
  11         public enum HashValueType\r
  12         {\r
  13                 /// <summary>\r
  14                 /// ファイルのサイズ(容量)をバイト単位で返す\r
  15                 /// </summary>\r
  16                 [XmlEnum(Name="size")]\r
  17                 SIZE,\r
  18                 [XmlEnum(Name="md5")]\r
  19                 MD5SUM,\r
  20                 [XmlEnum(Name="sha1")]\r
  21                 SHA1SUM,\r
  22                 [XmlEnum(Name="sha256")]\r
  23                 SHA256SUM,\r
  24         }\r
  25         \r
  26         public class HashValue\r
  27         {\r
  28                 /// <summary>\r
  29                 /// ハッシュ値の種類(計算法)\r
  30                 /// </summary>\r
  31                 [XmlAttribute]\r
  32                 public HashValueType Type;\r
  33                 \r
  34                 /// <summary>\r
  35                 /// ハッシュ値そのものをあらわす\r
  36                 /// </summary>\r
  37                 [XmlText]\r
  38                 public string Value;\r
  39                 \r
  40                 /// <summary>\r
  41                 /// コンストラクタ\r
  42                 /// </summary>\r
  43                 public HashValue()\r
  44                 {\r
  45                 }\r
  46                 \r
  47                 /// <summary>\r
  48                 /// 与えられたファイルのハッシュ値が同一であるか検証する\r
  49                 /// </summary>\r
  50                 /// <param name="path">ハッシュ計算を行う対象のファイル</param>\r
  51                 /// <returns>ファイルのハッシュ値が妥当な場合true。</returns>\r
  52                 public bool Validate(string path)\r
  53                 {\r
  54                         return string.Compare(this.Value, HashValueFor(path, this.Type), true) == 0;\r
  55                 }\r
  56                 \r
  57                 /// <summary>\r
  58                 /// ファイルのハッシュを計算する\r
  59                 /// </summary>\r
  60                 /// <param name="file">計算対象のファイル</param>\r
  61                 /// <param name="type">ハッシュの種類(計算法)</param>\r
  62                 /// <returns></returns>\r
  63                 public static string HashValueFor(string file, HashValueType type)\r
  64                 {\r
  65                         using (FileStream fs = new FileStream(file, FileMode.Open)) {\r
  66                                 return HashValue.HashValueFor(fs, type);\r
  67                         }\r
  68                 }\r
  69                 \r
  70                 /// <summary>\r
  71                 /// ストリーム入力からハッシュを計算する\r
  72                 /// </summary>\r
  73                 /// <param name="stream">ストリーム入力</param>\r
  74                 /// <param name="type">ハッシュの種類(計算法)</param>\r
  75                 /// <returns>ハッシュ値</returns>\r
  76                 public static string HashValueFor(Stream stream, HashValueType type)\r
  77                 {\r
  78                         byte[] hash;\r
  79                         \r
  80                         switch (type) {\r
  81                                 case HashValueType.SIZE:\r
  82                                         return stream.Length.ToString();\r
  83                                 case HashValueType.MD5SUM:\r
  84                                         hash = MD5.Create().ComputeHash(stream);\r
  85                                         break;\r
  86                                 case HashValueType.SHA1SUM:\r
  87                                         hash = SHA1.Create().ComputeHash(stream);\r
  88                                         break;\r
  89                                 case HashValueType.SHA256SUM:\r
  90                                         hash = SHA256.Create().ComputeHash(stream);\r
  91                                         break;\r
  92                                 default:\r
  93                                         throw new NotSupportedException(string.Format("Hash type {0} does not supported", type));\r
  94                         }\r
  95                         \r
  96                         return BitConverter.ToString(hash).Replace("-",string.Empty);\r
  97                 }\r
  98         }\r
  99 }\r