.Net 使用 AES 和 128 位初始化向量加密 XML 流
.Net Encrypt XML stream with AES and 128 bit Initialization vector
我正在开展一个项目，我正在通过 XML 流 post 访问 Web 服务。在这种情况下，提供商请求路由 xml 在密码块链接 (CBC) 模式下使用高级加密标准 (AES) 和 128 位初始化向量进行加密。我在 VB.Net 中编码，据我所知，我已经满足了他们所有的加密要求，但是当我提交 post 时，我不断收到 "Invalid Routing Input encryption" 错误响应。我在加密方面做得不多，所以我希望有一些加密经验的人可以帮助我。它失败是因为我没有正确地为 IV 加上前缀吗？ AES 中是否有将 IV 合并到密码数据的标准方法？还是我自己进行加密的方式有问题？我被困在这里一段时间并尝试了几种不同的加密方式但没有成功。下面列出了我的代码和加密要求的摘要。
使用高级加密标准 (AES) 在密码块链接 (CBC) 模式下使用 128 位初始化向量 [AES] 算法生成对称密钥。不要使用零字节初始化向量。
使用 AES 对称密钥加密有效的路由输入 xml 文档。使用 128 位初始化向量为生成的密文添加前缀。 （不建议使用全 0 字节的初始化向量。）
Base64 对初始化向量和加密的路由输入 xml 文档进行编码。
使用 base64 编码的初始化向量和加密的路由输入 xml 文档构建 ENCRYPTED_RI xml 元素。
为明文路由输入 xml 文档生成 SHA1 哈希。
连接明文路由输入 xml 文档的 SHA1 散列和 AES 对称密钥。 （SHA1 哈希 + AES 对称密钥）
使用 public 密钥和 RSA 1.5 版算法 [RFC 2437] 对连接结果进行加密。
Base64 对加密后的拼接结果进行编码。
使用 base64 编码的加密串联结果构建 ENCRYPTED_KEY xml 元素。
这是我的代码：
Sub CreateEncryptionXML()
'############
'## CREATE AES KEY AND IV
'############
Dim SymKey() As Byte
Dim IV() As Byte
Dim aes As New AesCryptoServiceProvider
Using myAes As Aes = System.Security.Cryptography.Aes.Create()
myAes.KeySize = 128
myAes.BlockSize = 128
myAes.Mode = CipherMode.CBC
myAes.Key = Encoding.UTF8.GetBytes("MyEncryptionKey1")
myAes.IV = Encoding.UTF8.GetBytes("MyInitialVector1")
SymKey = myAes.Key
IV = myAes.IV
End Using
'############
'## ENCRYPT ROUTING INPUT XML DOC
'############
Dim riXml As New XmlDocument
riXml.Load("C:\routingdoc.xml")
aes.Key = SymKey
aes.IV = IV
aes.Mode = CipherMode.CBC
' Convert the plaintext string to a byte array.
Dim plaintextBytes() As Byte = System.Text.Encoding.UTF8.GetBytes(riXml.OuterXml.ToString())
' Create the stream.
Dim ms As New System.IO.MemoryStream
' Create the encoder to write to the stream.
Dim encStream As New CryptoStream(ms, aes.CreateEncryptor(), System.Security.Cryptography.CryptoStreamMode.Write)
' Use the crypto stream to write the byte array to the stream.
encStream.Write(plaintextBytes, 0, plaintextBytes.Length)
encStream.FlushFinalBlock()
'############
'## PREFIX CIPHER TEXT WITH IV
'############
Dim encRiXml() As Byte = ms.ToArray
Dim arraySize As Integer = IV.Length + encRiXml.Length
Dim Merged(arraySize) As Byte
IV.CopyTo(Merged, 0)
encRiXml.CopyTo(Merged, IV.Length)
Dim Base64IVEncRiXML As String = Convert.ToBase64String(Merged)
'******** I BELIVE EVERYTHING PAST HERE IS CORRECT BUT INCLUDED IT TO SHOW WHOLE PROCESS **********
'############
'## CREATE SHA1 HASH FOR PLAINTEXT ROUTING INPUT
'############
Dim hash() As Byte = New SHA1Managed().ComputeHash(Encoding.UTF8.GetBytes(riXml.OuterXml.ToString()))
'############
'## CONCATENATE THE SHA1 HASH OF PLAINTEXT ROUTING INPUT XML WITH AES KEY
'############
Dim arraySize2 As Integer = hash.Length + SymKey.Length
Dim Merged2(arraySize2) As Byte
hash.CopyTo(Merged2, 0)
SymKey.CopyTo(Merged2, hash.Length)
'############
'## ENCRYPT CONCATENATED RESULT USING RSA
'############
Dim EncryptionKey As String = File.ReadAllText("C:\cert-1.txt").Replace("-----BEGIN CERTIFICATE-----" & vbCr & vbLf, "").Replace("-----END CERTIFICATE-----", "")
TextBox1.Text = EncryptionKey
Dim binaryCertData() As Byte = Convert.FromBase64String(EncryptionKey)
Dim cert As X509Certificate2 = New X509Certificate2(binaryCertData)
Dim xmlKey As String = cert.PublicKey.Key.ToXmlString(False)
Dim objRSA As RSACryptoServiceProvider = New RSACryptoServiceProvider()
objRSA.FromXmlString(xmlKey)
Dim encrypted() As Byte = objRSA.Encrypt(Merged2, False)
Dim RSAEncryptedSHA1HashAESKey As String = Convert.ToBase64String(encrypted)
postStaticTest(RSAEncryptedSHA1HashAESKey, Base64IVEncRiXML)
End Sub
'PROVIDED SAMPLE OF XML OUTPUT FROM DOCUMENTATION
'<?xml version="1.0" encoding="UTF-8"?>
'<SECURE_REQUEST_GROUP>
'<ENCRYPTED_KEY Algorithm=”http://www.w3.org/2001/04/xmlenc#rsa-1_5” >
'bXcCaS97p8TtGzlgZ9ogRcEAaw1D1OQCpk1AQFfWYE5J2CheNtRBpuME+uB3wSkwjIWftkYxQ5JRTQ3Qhz7LrCM+TOORl2lFFTpVC9zGUP1xndfT6EQONViV0XGJieWCzXNyjO3XpEl7IdntkVKucrDN9gA7wlimUdw4Ya5sn08=
'</ ENCRYPTED_KEY>
'< ENCRYPTED_RI Algorithm=”http://www.w3.org/2001/04/xmlenc#aes128-cbc”>
'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
'</ ENCRYPTED_RI>
'</SECURE_REQUEST_GROUP>
还有几个未解决的实施问题（我想我已经通过我使用的值明确了哪些问题）。这绝对应该重构，我这样做是为了说明如何满足每个要求。
Imports System.Security.Cryptography
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography.X509Certificates
Public Class SoAnswer
Dim keySize As Integer = 128
Public Function EncryptData() As XDocument
Dim encoder As UTF8Encoding = New UTF8Encoding()
'Specifed Root Name in Declaration
Dim outputDocument As XDocument = New XDocument(New XElement("SECURE_REQUEST_GROUP"))
outputDocument.Declaration = New XDeclaration("1.0", "utf-8", "true")
'outputDocument.Root.Name = "Whatever they specify the root of the xml should be"
Dim riXml As XDocument
Dim file As FileStream = New FileStream("C:\routingdoc.xml", FileMode.Open, FileAccess.Read)
riXml = XDocument.Load(file)
Dim symKey As Byte() = Requirement1(keySize)
Dim encryptedXml As Byte() = Requirement2(encoder.GetBytes(riXml.ToString()), symKey)
Dim encodedXml = Requirement3(encryptedXml)
'Moved Requirement 4 below requirement 9 so it will appear below the key in the output XML
'Requirement4(encodedXml, outputDocument)
Dim hash As Byte() = Requirement5(riXml)
Dim hashKey = Requirement6(hash, symKey)
Dim encryptedHashKey = Requirement7(hashKey)
Dim encodedHashKey = Requirement8(encryptedHashKey)
Requirement9(encodedHashKey, outputDocument)
Requirement4(encodedXml, outputDocument)
'Now you should have an XDocument with the proper content to POST to the web service
'Decrypt check
Dim check As String = encoder.GetString(Decrypt(Convert.FromBase64String(encodedXml), symKey))
postStaticTestXML(outputDocument.ToString)
End Function
Private Function Requirement1(size As Integer) As Byte()
Using aes As New AesCryptoServiceProvider()
aes.KeySize = size
aes.GenerateKey()
Return aes.Key
End Using
End Function
Private Function Requirement2(data() As Byte, key() As Byte) As Byte()
Using aes As New AesCryptoServiceProvider()
Dim iv As Byte() = aes.IV
Using encryptor As ICryptoTransform = aes.CreateEncryptor(key, iv)
Using msEncrypt As MemoryStream = New MemoryStream()
Using csEncrypt As CryptoStream = New CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)
csEncrypt.Write(data, 0, data.Length)
csEncrypt.FlushFinalBlock()
Dim encryptedData As Byte() = msEncrypt.ToArray()
Dim buffer(iv.Length + encryptedData.Length - 1) As Byte
buffer = CombineArrays(iv, encryptedData)
Return buffer
End Using
End Using
End Using
End Using
End Function
Private Function Requirement3(content As Byte()) As String
Return Convert.ToBase64String(content)
End Function
Private Sub Requirement4(content As String, ByRef doc As XDocument)
'added XAttribute to accommodate the required algorithm attribute
doc.Root.Add(New XElement("ENCRYPTED_RI", content, New XAttribute("Algorithm", "http://www.w3.org/2001/04/xmlenc#aes128-cbc")))
End Sub
Private Function Requirement5(content As XDocument) As Byte()
Dim encoder As UTF8Encoding = New UTF8Encoding()
Using hash As New SHA1CryptoServiceProvider()
Return hash.ComputeHash(encoder.GetBytes(content.ToString()))
End Using
End Function
Private Function Requirement6(hash As Byte(), key As Byte()) As Byte()
Return CombineArrays(hash, key)
End Function
Private Function Requirement7(content As Byte()) As Byte()
'I'm assuming here that they originally sent you a .cer file with their private key in it
'Dim cert As X509Certificate2 = X509Certificate2.CreateFromCertFile("path\filename of .cer file")
'X509Certificate2 Could not be directly specified with CreateFromCertFile. A new instance was created and set to derive its value from the retrieved X509Certificate
Dim cert As X509Certificate2 = New X509Certificate2(X509Certificate.CreateFromCertFile("C:\cert-1.txt"))
Using rsa As RSACryptoServiceProvider = cert.PublicKey.Key
'This assumes PKCS7 padding which is most common
Return rsa.Encrypt(content, False)
End Using
End Function
Private Function Requirement8(content As Byte()) As String
Return Convert.ToBase64String(content)
End Function
Private Sub Requirement9(content As String, ByRef doc As XDocument)
'Added XAttribute to accommodate for the required "Algorithm" attribute
doc.Root.Add(New XElement("ENCRYPTED_KEY", content, New XAttribute("Algorithm", "http://www.w3.org/2001/04/xmlenc#rsa-1_5")))
End Sub
'Support function
Private Function CombineArrays(array1 As Byte(), array2 As Byte())
Dim buffer(array1.Length + array2.Length - 1) as Byte
System.Buffer.BlockCopy(array1, 0, buffer, 0, array1.Length)
System.Buffer.BlockCopy(array2, 0, buffer, array1.Length, array2.Length)
Return buffer
End Function
Private Function Decrypt(data() As Byte, key() As Byte) As Byte()
Dim iv((128 / 8) - 1) As Byte
Buffer.BlockCopy(data, 0, iv, 0, iv.Length)
Dim value(data.Length - iv.Length - 1) As Byte
Buffer.BlockCopy(data, iv.Length, value, 0, value.Length)
Using aes As AesCryptoServiceProvider = New AesCryptoServiceProvider()
Using decryptor As ICryptoTransform = aes.CreateDecryptor(key, iv)
Using msDecrypt As MemoryStream = New MemoryStream(value)
Using csDecrypt As CryptoStream = New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)
Dim decrypted(msDecrypt.Length - 1) As Byte
csDecrypt.Read(decrypted, 0, decrypted.Length)
Return RemovePadding(decrypted)
End Using
End Using
End Using
End Using
End Function
Private Function RemovePadding(data As Byte()) As Byte()
Dim trimCount As Integer = 0
For i As Integer = data.Length - 1 To data.Length - (128 / 8) + 1 Step -1
If data(i) = 0 Then trimCount += 1 Else Exit For
Next
If trimCount <= 0 Then Return data
Dim buffer((data.Length - trimCount) - 1) As Byte
System.Buffer.BlockCopy(data, 0, buffer, 0, buffer.Length)
Return buffer
End Function
End Class
我正在开展一个项目，我正在通过 XML 流 post 访问 Web 服务。在这种情况下，提供商请求路由 xml 在密码块链接 (CBC) 模式下使用高级加密标准 (AES) 和 128 位初始化向量进行加密。我在 VB.Net 中编码，据我所知，我已经满足了他们所有的加密要求，但是当我提交 post 时，我不断收到 "Invalid Routing Input encryption" 错误响应。我在加密方面做得不多，所以我希望有一些加密经验的人可以帮助我。它失败是因为我没有正确地为 IV 加上前缀吗？ AES 中是否有将 IV 合并到密码数据的标准方法？还是我自己进行加密的方式有问题？我被困在这里一段时间并尝试了几种不同的加密方式但没有成功。下面列出了我的代码和加密要求的摘要。
使用高级加密标准 (AES) 在密码块链接 (CBC) 模式下使用 128 位初始化向量 [AES] 算法生成对称密钥。不要使用零字节初始化向量。
使用 AES 对称密钥加密有效的路由输入 xml 文档。使用 128 位初始化向量为生成的密文添加前缀。 （不建议使用全 0 字节的初始化向量。）
Base64 对初始化向量和加密的路由输入 xml 文档进行编码。
使用 base64 编码的初始化向量和加密的路由输入 xml 文档构建 ENCRYPTED_RI xml 元素。
为明文路由输入 xml 文档生成 SHA1 哈希。
连接明文路由输入 xml 文档的 SHA1 散列和 AES 对称密钥。 （SHA1 哈希 + AES 对称密钥）
使用 public 密钥和 RSA 1.5 版算法 [RFC 2437] 对连接结果进行加密。
Base64 对加密后的拼接结果进行编码。
使用 base64 编码的加密串联结果构建 ENCRYPTED_KEY xml 元素。
这是我的代码：
Sub CreateEncryptionXML()
'############
'## CREATE AES KEY AND IV
'############
Dim SymKey() As Byte
Dim IV() As Byte
Dim aes As New AesCryptoServiceProvider
Using myAes As Aes = System.Security.Cryptography.Aes.Create()
myAes.KeySize = 128
myAes.BlockSize = 128
myAes.Mode = CipherMode.CBC
myAes.Key = Encoding.UTF8.GetBytes("MyEncryptionKey1")
myAes.IV = Encoding.UTF8.GetBytes("MyInitialVector1")
SymKey = myAes.Key
IV = myAes.IV
End Using
'############
'## ENCRYPT ROUTING INPUT XML DOC
'############
Dim riXml As New XmlDocument
riXml.Load("C:\routingdoc.xml")
aes.Key = SymKey
aes.IV = IV
aes.Mode = CipherMode.CBC
' Convert the plaintext string to a byte array.
Dim plaintextBytes() As Byte = System.Text.Encoding.UTF8.GetBytes(riXml.OuterXml.ToString())
' Create the stream.
Dim ms As New System.IO.MemoryStream
' Create the encoder to write to the stream.
Dim encStream As New CryptoStream(ms, aes.CreateEncryptor(), System.Security.Cryptography.CryptoStreamMode.Write)
' Use the crypto stream to write the byte array to the stream.
encStream.Write(plaintextBytes, 0, plaintextBytes.Length)
encStream.FlushFinalBlock()
'############
'## PREFIX CIPHER TEXT WITH IV
'############
Dim encRiXml() As Byte = ms.ToArray
Dim arraySize As Integer = IV.Length + encRiXml.Length
Dim Merged(arraySize) As Byte
IV.CopyTo(Merged, 0)
encRiXml.CopyTo(Merged, IV.Length)
Dim Base64IVEncRiXML As String = Convert.ToBase64String(Merged)
'******** I BELIVE EVERYTHING PAST HERE IS CORRECT BUT INCLUDED IT TO SHOW WHOLE PROCESS **********
'############
'## CREATE SHA1 HASH FOR PLAINTEXT ROUTING INPUT
'############
Dim hash() As Byte = New SHA1Managed().ComputeHash(Encoding.UTF8.GetBytes(riXml.OuterXml.ToString()))
'############
'## CONCATENATE THE SHA1 HASH OF PLAINTEXT ROUTING INPUT XML WITH AES KEY
'############
Dim arraySize2 As Integer = hash.Length + SymKey.Length
Dim Merged2(arraySize2) As Byte
hash.CopyTo(Merged2, 0)
SymKey.CopyTo(Merged2, hash.Length)
'############
'## ENCRYPT CONCATENATED RESULT USING RSA
'############
Dim EncryptionKey As String = File.ReadAllText("C:\cert-1.txt").Replace("-----BEGIN CERTIFICATE-----" & vbCr & vbLf, "").Replace("-----END CERTIFICATE-----", "")
TextBox1.Text = EncryptionKey
Dim binaryCertData() As Byte = Convert.FromBase64String(EncryptionKey)
Dim cert As X509Certificate2 = New X509Certificate2(binaryCertData)
Dim xmlKey As String = cert.PublicKey.Key.ToXmlString(False)
Dim objRSA As RSACryptoServiceProvider = New RSACryptoServiceProvider()
objRSA.FromXmlString(xmlKey)
Dim encrypted() As Byte = objRSA.Encrypt(Merged2, False)
Dim RSAEncryptedSHA1HashAESKey As String = Convert.ToBase64String(encrypted)
postStaticTest(RSAEncryptedSHA1HashAESKey, Base64IVEncRiXML)
End Sub
'PROVIDED SAMPLE OF XML OUTPUT FROM DOCUMENTATION
'<?xml version="1.0" encoding="UTF-8"?>
'<SECURE_REQUEST_GROUP>
'<ENCRYPTED_KEY Algorithm=”http://www.w3.org/2001/04/xmlenc#rsa-1_5” >
'bXcCaS97p8TtGzlgZ9ogRcEAaw1D1OQCpk1AQFfWYE5J2CheNtRBpuME+uB3wSkwjIWftkYxQ5JRTQ3Qhz7LrCM+TOORl2lFFTpVC9zGUP1xndfT6EQONViV0XGJieWCzXNyjO3XpEl7IdntkVKucrDN9gA7wlimUdw4Ya5sn08=
'</ ENCRYPTED_KEY>
'< ENCRYPTED_RI Algorithm=”http://www.w3.org/2001/04/xmlenc#aes128-cbc”>
'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
'</ ENCRYPTED_RI>
'</SECURE_REQUEST_GROUP>
还有几个未解决的实施问题（我想我已经通过我使用的值明确了哪些问题）。这绝对应该重构，我这样做是为了说明如何满足每个要求。
Imports System.Security.Cryptography
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography.X509Certificates
Public Class SoAnswer
Dim keySize As Integer = 128
Public Function EncryptData() As XDocument
Dim encoder As UTF8Encoding = New UTF8Encoding()
'Specifed Root Name in Declaration
Dim outputDocument As XDocument = New XDocument(New XElement("SECURE_REQUEST_GROUP"))
outputDocument.Declaration = New XDeclaration("1.0", "utf-8", "true")
'outputDocument.Root.Name = "Whatever they specify the root of the xml should be"
Dim riXml As XDocument
Dim file As FileStream = New FileStream("C:\routingdoc.xml", FileMode.Open, FileAccess.Read)
riXml = XDocument.Load(file)
Dim symKey As Byte() = Requirement1(keySize)
Dim encryptedXml As Byte() = Requirement2(encoder.GetBytes(riXml.ToString()), symKey)
Dim encodedXml = Requirement3(encryptedXml)
'Moved Requirement 4 below requirement 9 so it will appear below the key in the output XML
'Requirement4(encodedXml, outputDocument)
Dim hash As Byte() = Requirement5(riXml)
Dim hashKey = Requirement6(hash, symKey)
Dim encryptedHashKey = Requirement7(hashKey)
Dim encodedHashKey = Requirement8(encryptedHashKey)
Requirement9(encodedHashKey, outputDocument)
Requirement4(encodedXml, outputDocument)
'Now you should have an XDocument with the proper content to POST to the web service
'Decrypt check
Dim check As String = encoder.GetString(Decrypt(Convert.FromBase64String(encodedXml), symKey))
postStaticTestXML(outputDocument.ToString)
End Function
Private Function Requirement1(size As Integer) As Byte()
Using aes As New AesCryptoServiceProvider()
aes.KeySize = size
aes.GenerateKey()
Return aes.Key
End Using
End Function
Private Function Requirement2(data() As Byte, key() As Byte) As Byte()
Using aes As New AesCryptoServiceProvider()
Dim iv As Byte() = aes.IV
Using encryptor As ICryptoTransform = aes.CreateEncryptor(key, iv)
Using msEncrypt As MemoryStream = New MemoryStream()
Using csEncrypt As CryptoStream = New CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)
csEncrypt.Write(data, 0, data.Length)
csEncrypt.FlushFinalBlock()
Dim encryptedData As Byte() = msEncrypt.ToArray()
Dim buffer(iv.Length + encryptedData.Length - 1) As Byte
buffer = CombineArrays(iv, encryptedData)
Return buffer
End Using
End Using
End Using
End Using
End Function
Private Function Requirement3(content As Byte()) As String
Return Convert.ToBase64String(content)
End Function
Private Sub Requirement4(content As String, ByRef doc As XDocument)
'added XAttribute to accommodate the required algorithm attribute
doc.Root.Add(New XElement("ENCRYPTED_RI", content, New XAttribute("Algorithm", "http://www.w3.org/2001/04/xmlenc#aes128-cbc")))
End Sub
Private Function Requirement5(content As XDocument) As Byte()
Dim encoder As UTF8Encoding = New UTF8Encoding()
Using hash As New SHA1CryptoServiceProvider()
Return hash.ComputeHash(encoder.GetBytes(content.ToString()))
End Using
End Function
Private Function Requirement6(hash As Byte(), key As Byte()) As Byte()
Return CombineArrays(hash, key)
End Function
Private Function Requirement7(content As Byte()) As Byte()
'I'm assuming here that they originally sent you a .cer file with their private key in it
'Dim cert As X509Certificate2 = X509Certificate2.CreateFromCertFile("path\filename of .cer file")
'X509Certificate2 Could not be directly specified with CreateFromCertFile. A new instance was created and set to derive its value from the retrieved X509Certificate
Dim cert As X509Certificate2 = New X509Certificate2(X509Certificate.CreateFromCertFile("C:\cert-1.txt"))
Using rsa As RSACryptoServiceProvider = cert.PublicKey.Key
'This assumes PKCS7 padding which is most common
Return rsa.Encrypt(content, False)
End Using
End Function
Private Function Requirement8(content As Byte()) As String
Return Convert.ToBase64String(content)
End Function
Private Sub Requirement9(content As String, ByRef doc As XDocument)
'Added XAttribute to accommodate for the required "Algorithm" attribute
doc.Root.Add(New XElement("ENCRYPTED_KEY", content, New XAttribute("Algorithm", "http://www.w3.org/2001/04/xmlenc#rsa-1_5")))
End Sub
'Support function
Private Function CombineArrays(array1 As Byte(), array2 As Byte())
Dim buffer(array1.Length + array2.Length - 1) as Byte
System.Buffer.BlockCopy(array1, 0, buffer, 0, array1.Length)
System.Buffer.BlockCopy(array2, 0, buffer, array1.Length, array2.Length)
Return buffer
End Function
Private Function Decrypt(data() As Byte, key() As Byte) As Byte()
Dim iv((128 / 8) - 1) As Byte
Buffer.BlockCopy(data, 0, iv, 0, iv.Length)
Dim value(data.Length - iv.Length - 1) As Byte
Buffer.BlockCopy(data, iv.Length, value, 0, value.Length)
Using aes As AesCryptoServiceProvider = New AesCryptoServiceProvider()
Using decryptor As ICryptoTransform = aes.CreateDecryptor(key, iv)
Using msDecrypt As MemoryStream = New MemoryStream(value)
Using csDecrypt As CryptoStream = New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)
Dim decrypted(msDecrypt.Length - 1) As Byte
csDecrypt.Read(decrypted, 0, decrypted.Length)
Return RemovePadding(decrypted)
End Using
End Using
End Using
End Using
End Function
Private Function RemovePadding(data As Byte()) As Byte()
Dim trimCount As Integer = 0
For i As Integer = data.Length - 1 To data.Length - (128 / 8) + 1 Step -1
If data(i) = 0 Then trimCount += 1 Else Exit For
Next
If trimCount <= 0 Then Return data
Dim buffer((data.Length - trimCount) - 1) As Byte
System.Buffer.BlockCopy(data, 0, buffer, 0, buffer.Length)
Return buffer
End Function
End Class