ECDiffieHellmanCng entschlüsselt die Daten nicht

  • VB.NET
  • .NET (FX) 4.0

Es gibt 2 Antworten in diesem Thema. Der letzte Beitrag () ist von exc-jdbi.

    ECDiffieHellmanCng entschlüsselt die Daten nicht

    Hi Leute,
    ich hänge hier an dem Problem mit der ECDiffieHellmanCng Klasse. Ich will eine Nachricht verschlüsselt mit dem PublicKey vom Partner und meinem PublicKey(?). Das verschlüsseln funktioniert zwar, allerdings nicht das entschlüsseln. Weiß jemand woran dies liegen kann?
    Ich bekomme die Fehlermeldung: Der angegebene Schlüssel hat keine gültige Größe für diesen Algorithmus.

    Hier mal der Code
    Spoiler anzeigen
    ​

    VB.NET-Quellcode

    1. ​Imports System
    2. Imports System.IO
    3. Imports System.Security.Cryptography
    4. Imports System.Text
    5. Public Class Form1
    6. Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    7. 'Create Keys
    8. Dim p As Keys = CreateKeys(CngAlgorithm.ECDiffieHellmanP521, CngAlgorithm.Sha512)
    9. Dim PrivateKey As Byte() = p.PrivateKey
    10. Dim PublicKey As Byte() = p.PublicKey
    12. 'Encrypt Message
    13. Dim Message As String = "Hello World"
    14. Dim IV As Byte() = {23, 45, 76, 22, 100, 142, 244, 83}
    15. Dim encryptData_ As Byte() = EncryptData(System.Text.UTF8Encoding.UTF8.GetBytes(Message), PublicKey, Algorithm.AES, IV)
    17. 'Decrypt Message
    18. MsgBox(DecryptData(encryptData_, PrivateKey, IV))
    19. End Sub
    21. Private ECDiffieHellman_ As ECDiffieHellmanCng
    22. Private Structure Keys
    23. Public PrivateKey As Byte()
    24. Public PublicKey As Byte()
    25. End Structure
    26. Private Function CreateKeys(ByVal CngAlgorithm_ As CngAlgorithm, Optional ByVal HashAlgorithm_ As CngAlgorithm = Nothing, Optional ByVal KeyName As String = Nothing) As Keys
    27. ECDiffieHellman_ = New ECDiffieHellmanCng(CngKey.Create(CngAlgorithm_, KeyName, New CngKeyCreationParameters() With {.ExportPolicy = CngExportPolicies.AllowPlaintextExport}))
    28. Select Case HashAlgorithm_
    29. Case Nothing
    30. ECDiffieHellman_.HashAlgorithm = CngAlgorithm.Sha256
    31. Case Else
    32. ECDiffieHellman_.HashAlgorithm = HashAlgorithm_
    33. End Select
    34. Using Keys_ As ECDiffieHellmanCng = ECDiffieHellman_
    35. Keys_.DeriveKeyMaterial(CngKey.Import(ECDiffieHellman_.PublicKey.ToByteArray, CngKeyBlobFormat.EccPublicBlob))
    36. Keys_.KeyDerivationFunction = ECDiffieHellmanKeyDerivationFunction.Hash
    37. Keys_.HashAlgorithm = CngAlgorithm.Sha256
    38. Dim KeysNew As New Keys
    39. KeysNew.PrivateKey = Keys_.Key.Export(CngKeyBlobFormat.EccPrivateBlob)
    40. KeysNew.PublicKey = Keys_.Key.Export(CngKeyBlobFormat.EccPublicBlob)
    41. Return KeysNew
    42. End Using
    44. End Function
    45. Enum Algorithm
    46. AES
    47. DES
    48. TDES
    49. End Enum
    50. Private Function EncryptData(ByVal Data As Byte(), ByVal PublicKey As Byte(), ByVal Algo As Algorithm, Optional ByVal iv As Byte() = Nothing) As Byte()
    51. Select Case Algo
    52. Case Algorithm.AES
    53. Using aes As New AesCryptoServiceProvider()
    54. iv = aes.IV
    55. ' Encrypt the message
    56. Using ciphertext As New MemoryStream()
    57. Using cs As New CryptoStream(ciphertext, aes.CreateEncryptor(), CryptoStreamMode.Write)
    58. Dim plaintextMessage As Byte() = Data
    59. cs.Write(plaintextMessage, 0, plaintextMessage.Length)
    60. cs.Close()
    61. Return ciphertext.ToArray()
    62. End Using
    63. End Using
    64. End Using
    65. Case Algorithm.DES
    66. Using des As New DESCryptoServiceProvider()
    67. iv = des.IV
    68. ' Encrypt the message
    69. Using ciphertext As New MemoryStream()
    70. Using cs As New CryptoStream(ciphertext, des.CreateEncryptor(), CryptoStreamMode.Write)
    71. Dim plaintextMessage As Byte() = Data
    72. cs.Write(plaintextMessage, 0, plaintextMessage.Length)
    73. cs.Close()
    74. Return ciphertext.ToArray()
    75. End Using
    76. End Using
    77. End Using
    78. Case Algorithm.TDES
    79. Using tdes As New TripleDESCryptoServiceProvider
    80. iv = tdes.IV
    81. ' Encrypt the message
    82. Using ciphertext As New MemoryStream()
    83. Using cs As New CryptoStream(ciphertext, tdes.CreateEncryptor(), CryptoStreamMode.Write)
    84. Dim plaintextMessage As Byte() = Data
    85. cs.Write(plaintextMessage, 0, plaintextMessage.Length)
    86. cs.Close()
    87. Return ciphertext.ToArray()
    88. End Using
    89. End Using
    90. End Using
    91. End Select
    92. End Function
    93. Private Function DecryptData(ByVal EncryptData As Byte(), ByVal PrivateKey As Byte(), ByVal iv As Byte()) As String
    94. Using aes As New AesCryptoServiceProvider()
    95. aes.Key = PrivateKey
    96. aes.IV = iv
    97. ' Decrypt the message
    98. Using plaintext As New MemoryStream()
    99. Using cs As New CryptoStream(plaintext, aes.CreateDecryptor(), CryptoStreamMode.Write)
    100. cs.Write(EncryptData, 0, EncryptData.Length)
    101. cs.Close()
    102. Dim message As String = Encoding.UTF8.GetString(plaintext.ToArray())
    103. Return message
    104. End Using
    105. End Using
    106. End Using
    107. End Function
    108. End Class

    //Edit

    Ok, habs gelöst bzw. hab jetzt alles hinbekommen. Hab da einiges falsch gemacht ^^
    Hier die Lösung:
    Spoiler anzeigen

    VB.NET-Quellcode

    1. Imports System.Security.Cryptography
    2. Imports System.IO
    3. Imports System.Text
    4. Public Class Diffie_Hellman_Encryption
    5. Private CreateCng As New ECDiffieHellmanCng
    6. Friend PublicKey As Byte() = CreateCng.PublicKey.ToByteArray
    7. ''' <summary>
    8. ''' Erstellt einen Key von dem PublicKey des Partners
    9. ''' </summary>
    10. ''' <param name="PublicKey">Der PublicKey des Partners</param>
    11. ''' <returns></returns>
    12. ''' <remarks></remarks>
    13. Friend Function CreateKey(ByVal PublicKey As Byte(), Optional ByVal KeyDerivationFunction As ECDiffieHellmanKeyDerivationFunction = ECDiffieHellmanKeyDerivationFunction.Hash, Optional ByVal HashAlgorithm As CngAlgorithm = Nothing) As Byte()
    14. CreateCng.KeyDerivationFunction = ECDiffieHellmanKeyDerivationFunction.Hash
    15. Select Case HashAlgorithm
    16. Case Nothing
    17. Case Else
    18. CreateCng.HashAlgorithm = CngAlgorithm.Sha256
    19. End Select
    20. Return CreateCng.DeriveKeyMaterial(CngKey.Import(PublicKey, CngKeyBlobFormat.EccPublicBlob))
    21. End Function
    23. Public Class Encrypt
    24. Friend Shared iv As Byte() = Nothing
    25. ''' <summary>
    26. ''' Verschlüsselt Daten in AES, hierzu wird der Key von dem PublicKey des Partners benötigt.
    27. ''' </summary>
    28. ''' <param name="Data">Die Daten die verschlüsselt werden sollen</param>
    29. ''' <param name="Key">Der Key von dem PublicKey des Partners</param>
    30. ''' <returns>Die Rückgabe ist Verschlüsselt aus den Daten</returns>
    31. ''' <remarks></remarks>
    32. Friend Shared Function EncryptData(ByVal Data As Byte(), ByVal Key As Byte()) As Byte()
    33. Using aes As New AesCryptoServiceProvider()
    34. aes.Key = Key
    35. iv = aes.IV
    36. Using ciphertext As New MemoryStream()
    37. Using cs As New CryptoStream(ciphertext, aes.CreateEncryptor(), CryptoStreamMode.Write)
    38. cs.Write(Data, 0, Data.Length)
    39. cs.Close()
    40. Return ciphertext.ToArray()
    41. End Using
    42. End Using
    43. End Using
    44. End Function
    45. End Class
    46. Public Class Decrypt
    47. ''' <summary>
    48. ''' Die Verschlüsselten Daten werden entschlüsselt.
    49. ''' </summary>
    50. ''' <param name="Data">Hier kommen die Verschlüsselten Daten hin</param>
    51. ''' <param name="Key">Hier kommt der Key vom PublicKey des Partners hin</param>
    52. ''' <param name="IV">Hier kommt der IV von den Verschlüsselten Daten hin. Der IV hat der Nutzer der die Daten verschlüsselt hat.</param>
    53. ''' <returns></returns>
    54. ''' <remarks></remarks>
    55. Friend Shared Function DecryptData(ByVal Data As Byte(), ByVal Key As Byte(), ByVal IV As Byte()) As Byte()
    56. Using aes As New AesCryptoServiceProvider()
    57. aes.Key = Key
    58. aes.IV = IV
    59. Using plaintext As New MemoryStream()
    60. Using cs As New CryptoStream(plaintext, aes.CreateDecryptor(), CryptoStreamMode.Write)
    61. cs.Write(Data, 0, Data.Length)
    62. cs.Close()
    63. Return plaintext.ToArray()
    64. End Using
    65. End Using
    66. End Using
    67. End Function
    68. End Class
    69. End Class


    //Edit
    Hier mein Snippet: dotnet-snippets.de/snippet/dif…an-verschluesselung/15129

    Dieser Beitrag wurde bereits 2 mal editiert, zuletzt von „Mr. Johny“ ()

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