Cryptage de string

Bonjour
Voila , je touche bientot a la fin de mon application mais je m'aperçois que mon code pour decrypter n'est pas bon il m'ejecte .
j'ai meme recuperer un autre bout de code mais idem il m'indique string too long et pas de sortie.

voici les quatres fonctions

Code:

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Public Function AES_Encrypt(ByVal input As String, ByVal pass As String) As String
        Dim AES As New System.Security.Cryptography.RijndaelManaged
        Dim Hash_AES As New System.Security.Cryptography.MD5CryptoServiceProvider
        Dim encrypted As String = ""
        Try
            Dim hash(31) As Byte
            Dim temp As Byte() = Hash_AES.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(pass))
            Array.Copy(temp, 0, hash, 0, 16)
            Array.Copy(temp, 0, hash, 15, 16)
            AES.Key = hash
            AES.Mode = Security.Cryptography.CipherMode.ECB
            Dim DESEncrypter As System.Security.Cryptography.ICryptoTransform = AES.CreateEncryptor
            Dim Buffer As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(input)
            encrypted = Convert.ToBase64String(DESEncrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
            Return encrypted
        Catch ex As Exception
            Return Nothing
        End Try
    End Function
 
    Public Function AES_Decrypt(ByVal input As String, ByVal pass As String) As String
        Dim AES As New System.Security.Cryptography.RijndaelManaged
        Dim Hash_AES As New System.Security.Cryptography.MD5CryptoServiceProvider
        Dim decrypted As String = ""
        Try
            Dim hash(31) As Byte
            Dim temp As Byte() = Hash_AES.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(pass))
            Array.Copy(temp, 0, hash, 0, 16)
            Array.Copy(temp, 0, hash, 15, 16)
            AES.Key = hash
            AES.Mode = Security.Cryptography.CipherMode.ECB
            Dim DESDecrypter As System.Security.Cryptography.ICryptoTransform = AES.CreateDecryptor
            Dim Buffer As Byte() = Convert.FromBase64String(input)
            decrypted = System.Text.ASCIIEncoding.ASCII.GetString(DESDecrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
            Return decrypted
        Catch ex As Exception
            Return Nothing
        End Try
    End Function
 
    Public Function AESE(ByVal plaintext As String, ByVal key As String) As String
        Dim AES As New System.Security.Cryptography.RijndaelManaged
        Dim SHA256 As New System.Security.Cryptography.SHA256Cng
        Dim ciphertext As String = ""
        Try
            AES.GenerateIV()
            AES.Key = SHA256.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(key))
 
            AES.Mode = Security.Cryptography.CipherMode.CBC
            Dim DESEncrypter As System.Security.Cryptography.ICryptoTransform = AES.CreateEncryptor
            Dim Buffer As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(plaintext)
            ciphertext = Convert.ToBase64String(DESEncrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
 
            Return Convert.ToBase64String(AES.IV) & Convert.ToBase64String(DESEncrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
 
        Catch ex As Exception
            Return ex.Message
        End Try
    End Function
 
    Public Function AESD(ByVal ciphertext As String, ByVal key As String) As String
        Dim AES As New System.Security.Cryptography.RijndaelManaged
        Dim SHA256 As New System.Security.Cryptography.SHA256Cng
        Dim plaintext As String = ""
        Dim iv As String = ""
        Try
            Dim ivct = ciphertext.Split(CChar("="))
            iv = ivct(0) & "=="
            ciphertext = ivct(2) & "=="
 
            AES.Key = SHA256.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(key))
            AES.IV = Convert.FromBase64String(iv)
            AES.Mode = Security.Cryptography.CipherMode.CBC
            Dim DESDecrypter As System.Security.Cryptography.ICryptoTransform = AES.CreateDecryptor
            Dim Buffer As Byte() = Convert.FromBase64String(ciphertext)
            plaintext = System.Text.ASCIIEncoding.ASCII.GetString(DESDecrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
            Return plaintext
        Catch ex As Exception
            Return ex.Message
        End Try
    End Function

et pour les appeler j'ai dans mon code :

Code:

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temp = AESE("je veux coder cette phrase", "CODE")
temp = AESD(temp, "CODE")  'ici ca plante temp contient longueur des données a dechiffrer non valide
 
'et j'ai testé
temp = AES_Encrypt("je veux coder cette phrase",  "CODE")
temp=AES_Decrypt(temp,"CODE")
 
'j 'ai le meme resultat

avez vous une piste ou un bout de fonctions cryptage , decryptage ?

Merci

bonsoir,

http://stackoverflow.com/questions/3...algorithm-in-c

je n'ai pas trouvé mon bonheur la bas mais ailleurs si

Code:

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    Public Function AES_Decrypt(ByVal input As String, ByVal pass As String) As String
        Dim AES As New System.Security.Cryptography.RijndaelManaged
        Dim Hash_AES As New System.Security.Cryptography.MD5CryptoServiceProvider
        Dim decrypted As String = ""
        Try
            Dim hash(31) As Byte
            Dim temp As Byte() = Hash_AES.ComputeHash(System.Text.Encoding.Default.GetBytes(pass))
            Array.Copy(temp, 0, hash, 0, 16)
            Array.Copy(temp, 0, hash, 15, 16)
            AES.Key = hash
            AES.Mode = Security.Cryptography.CipherMode.ECB
            Dim DESDecrypter As System.Security.Cryptography.ICryptoTransform = AES.CreateDecryptor
            Dim Buffer As Byte() = Convert.FromBase64String(input)
            decrypted = System.Text.Encoding.Default.GetString(DESDecrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
            Return decrypted
        Catch ex As Exception
            Return Nothing
        End Try
    End Function

c'était donc le System.Text.ASCIIEncoding.ASCII. au lieu de system.text.Encoding.defaut qui mettait le bazar

a+