文字コードはUTF8でして、以下の復号ロジックの★マークの行
を修正しましところ復号化に成功しました。ところが、今度は、暗号化で、
------------------------
'復号化する
Public Function Decrypt(ByVal encryptoFileName As String, _
ByVal base64FileName As String, ByVal decryptoFileName
As String) As String
Dim objCryptoStream As System.Security.Cryptography.CryptoStream
Dim objRijndaelManaged As New System.Security.Cryptography.AesCryptoServiceProvider()
Dim objFileStream As System.IO.FileStream
Dim objStreamReader As System.IO.StreamReader
Dim objStreamWriter As System.IO.StreamWriter
Dim strData As String
Dim enc As System.Text.Encoding = System.Text.Encoding.GetEncoding("shift-jis")
'テキストファイルを開く
Dim srFile As New StreamReader(base64FileName, Encoding.GetEncoding("shift-jis"))
Dim strW As String = ""
Dim strLine As String = srFile.ReadLine
While Not strLine Is Nothing
strW &= strLine
strLine = srFile.ReadLine
End While
srFile.Close()
'バイト型配列に戻す
Dim bs() As Byte = System.Convert.FromBase64String(strW)
'ファイルに保存する
'保存するファイル名
Dim outFileName As String = encryptoFileName
'ファイルに書き込む
Dim outFile As New System.IO.FileStream(outFileName, _
System.IO.FileMode.Create, System.IO.FileAccess.Write)
outFile.Write(bs, 0, bs.Length)
outFile.Close()
' AES暗号化サービスプロバイダ
objRijndaelManaged.BlockSize = 128
objRijndaelManaged.KeySize = 256
objRijndaelManaged.IV = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
objRijndaelManaged.Key = enc.GetBytes("********************************")
objRijndaelManaged.Mode = CipherMode.ECB
objRijndaelManaged.Padding = PaddingMode.PKCS7
Try
objFileStream = New System.IO.FileStream(encryptoFileName, IO.FileMode.Open)
objCryptoStream = New System.Security.Cryptography.CryptoStream(objFileStream, objRijndaelManaged.CreateDecryptor(), Security.Cryptography.CryptoStreamMode.Read)
objStreamReader = New System.IO.StreamReader(objCryptoStream, System.Text.Encoding.UTF8) '★マーク
objStreamWriter = New System.IO.StreamWriter(decryptoFileName, False, System.Text.Encoding.GetEncoding("shift-jis"))
objStreamWriter.Write(objStreamReader.ReadToEnd)
objStreamReader.Close()
objStreamWriter.Close()
objFileStream.Close()
objCryptoStream.Close()
Catch Ex As Exception
MsgBox(Ex.Message, MsgBoxStyle.Exclamation)
End Try
End Function
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次に、暗号化しまして、復号化の第二パラメータのbase64FileName と
暗号化の第二パラメータのbase64FileName は同じ内容になるはずですが、
System.Text.Encodingの箇所をいろんなパターンでUTF8に変えて実行してみましたが、
同じ内容になりません。
以下の暗号化のロジックの何の原因が考えられるでしょうか？
'暗号化する
Public Function Encrypt(ByVal encryptoFileName As String, ByVal base64FileName As String, _
ByVal FileName As String) As String
Dim objCryptoStream As System.Security.Cryptography.CryptoStream
Dim objRijndaelManaged As New System.Security.Cryptography.AesCryptoServiceProvider()
Dim objFileStream As System.IO.FileStream
Dim objStreamReader As System.IO.StreamReader
Dim objStreamWriter As System.IO.StreamWriter
Dim strData As String
Dim enc As System.Text.Encoding = System.Text.Encoding.GetEncoding("shift-jis")
' AES暗号化サービスプロバイダ
objRijndaelManaged.BlockSize = 128
objRijndaelManaged.KeySize = 256
objRijndaelManaged.IV = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
objRijndaelManaged.Key = enc.GetBytes("********************************")
objRijndaelManaged.Mode = CipherMode.ECB
objRijndaelManaged.Padding = PaddingMode.PKCS7
Try
objFileStream = New System.IO.FileStream(encryptoFileName, System.IO.FileMode.Create)
objCryptoStream = New System.Security.Cryptography.CryptoStream(objFileStream, objRijndaelManaged.CreateEncryptor(), Security.Cryptography.CryptoStreamMode.Write)
objStreamWriter = New System.IO.StreamWriter(objCryptoStream, System.Text.Encoding.GetEncoding("shift-jis"))
objStreamReader = New System.IO.StreamReader(FileName, System.Text.Encoding.GetEncoding("shift-jis"))
objStreamWriter.Write(objStreamReader.ReadToEnd())
objStreamReader.Close()
objStreamWriter.Close()
objFileStream.Close()
objCryptoStream.Close()
'Base64で文字列に変換するファイル
Dim inFileName As String = encryptoFileName
Dim inFile As System.IO.FileStream
Dim bs() As Byte
'ファイルをbyte型配列としてすべて読み込む
inFile = New System.IO.FileStream(inFileName, _
System.IO.FileMode.Open, System.IO.FileAccess.Read)
ReDim bs(inFile.Length - 1)
Dim readBytes As Long = inFile.Read(bs, 0, inFile.Length)
inFile.Close()
'Base64で文字列に変換
Dim base64String As String
base64String = System.Convert.ToBase64String(bs)
'ファイルに保存する
'保存するファイル名
Dim outFileName As String = base64FileName
'ファイルに書き込む
Dim sw As IO.StreamWriter = New IO.StreamWriter(outFileName, False, System.Text.Encoding.GetEncoding("Shift_JIS"))
sw.Write(base64String)
sw.Close()
Catch Ex As Exception
MsgBox(Ex.Message, MsgBoxStyle.Exclamation)
End Try
End Function
