Example: Cipher.FileDecrypt  Cipher.FileEncrypt  Rng.Bytes  Tdea.BlockSize 

[VB6 equivalent: CIPHER_File]

Const MY_PATH As String = ""
Dim abKey() As Byte
Dim abIV() As Byte
Dim strFileEnc As String
Dim strFileIn As String
Dim strFileChk As String
Dim nRet As Integer

' Construct full path names to files
strFileIn = MY_PATH & "hello.txt"
strFileEnc = MY_PATH & "hello.aes128.enc.dat"
strFileChk = MY_PATH & "hello.aes128.chk.txt"

' Create the key as an array of bytes
' This creates an array of 16 bytes {&HFE, &HDC, ... &H10}
abKey = Cnv.FromHex("fedcba9876543210fedcba9876543210")
' Create the IV at random
''ReDim abIV(PKI_BLK_AES_BYTES - 1)
abIV = Rng.Bytes(Tdea.BlockSize)
' Display the IV (this needs to be communicated separately to the recipient)
Console.WriteLine("IV=" & Cnv.ToHex(abIV))

' Encrypt plaintext file to ciphertext using AES-128 in counter (CTR) mode
' (This will create a file of exactly the same size as the input)
nRet = Cipher.FileEncrypt(strFileEnc, strFileIn, abKey, abIV, CipherAlgorithm.Aes128, Mode.CTR)
Console.WriteLine("CIPHER_File(ENCRYPT) returns " & nRet)

' Now decrypt it
nRet = Cipher.FileDecrypt(strFileChk, strFileEnc, abKey, abIV, CipherAlgorithm.Aes128, Mode.CTR)
Console.WriteLine("CIPHER_File(DECRYPT) returns " & nRet)

See Also:
Cipher.FileDecrypt Method (String, String, Byte[], Byte[], CipherAlgorithm, Mode)
Cipher.FileEncrypt Method (String, String, Byte[], Byte[], CipherAlgorithm, Mode)

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