我使用以下两种方法来加密和解密字符串：
'Encrypts string. Returns encrypted byte array.
Public Function Encrypt(ByVal str As String) As Byte()
Dim inputInBytes() As Byte = Encoding.Unicode.GetBytes(str)
Dim laesProvider As New AesCryptoServiceProvider()
laesProvider.Key = _key
laesProvider.Mode = CipherMode.CBC
laesProvider.IV = _IV
laesProvider.Padding = PaddingMode.PKCS7
Dim lencryptor As ICryptoTransform = laesProvider.CreateEncryptor
Dim encryptedStream As New MemoryStream
Dim cryptStream As CryptoStream = New CryptoStream(encryptedStream, lencryptor, CryptoStreamMode.Write)
cryptStream.Write(inputInBytes, 0, inputInBytes.Length)
cryptStream.FlushFinalBlock()
encryptedStream.Position = 0
Dim result(encryptedStream.Length - 1) As Byte
encryptedStream.Read(result, 0, encryptedStream.Length)
cryptStream.Close()
Return result
End Function
'Decrypts bytearray. Returns string.
Public Function DecryptToStr(ByVal inputInBytes() As Byte) As String
Dim laesProvider As New AesCryptoServiceProvider()
laesProvider.Key = _key
laesProvider.Mode = CipherMode.CBC
laesProvider.IV = _IV
laesProvider.Padding = PaddingMode.PKCS7
Dim ldecryptor As ICryptoTransform = laesProvider.CreateDecryptor
' Provide a memory stream to decrypt information into
Dim decryptedStream As MemoryStream = New MemoryStream()
Dim cryptStream As CryptoStream = New CryptoStream(decryptedStream, ldecryptor, CryptoStreamMode.Write)
cryptStream.Write(inputInBytes, 0, inputInBytes.Length)
cryptStream.FlushFinalBlock() '#### This is where the exception is thrown ####
decryptedStream.Position = 0
' Read the memory stream and convert it back into a string
Dim result(decryptedStream.Length - 1) As Byte
decryptedStream.Read(result, 0, decryptedStream.Length)
cryptStream.Close()
Return Encoding.Unicode.GetString(result)
End Function
尝试解密某些长度的字符串时会发生错误。当字符串是社会保险号（包括破折号在内的 11 个字符）时，会抛出“输入数据不是完整的块”CryptographicException。例如，如果我传入一个正好 8 个字符长的字符串，那么一切都会按预期工作。我认为 PKCS7 填充会处理各种长度。我确定我遗漏了一些简单的东西，但是经过数小时的谷歌搜索，我无法找到答案。