DES_Bytes

Encrypts or decrypts an array of Bytes in one step in Electronic Codebook (EBC) mode.

@deprecated use DES_BytesMode with strMode="ECB".

VBA/VB6 Syntax

nRet = DES_Bytes(lpOutput(0), abData(0), nDataLen, abKey(0), bEncrypt) ' Note the "(0)" after the byte array parameters

C/C++ Syntax

Parameters

lpOutput

[out] array of sufficient length to receive the output.

lpInput

[in] array containing the input data.

nBytes

[in] equal to length of the input data in bytes.

lpKey

[in] array containing the key.

fEncrypt

[in] direction flag: set as ENCRYPT (True) to encrypt or DECRYPT (False) to decrypt.

Returns (VBA/C)

If successful, the return value is 0; otherwise it returns a non-zero error code.

.NET Equivalent

Des.Encrypt Method (Byte[], Byte[], Mode, Byte[])
Des.Decrypt Method (Byte[], Byte[], Mode, Byte[])
with mode=Mode.ECB.

Remarks

The input data lpData must be an exact multiple of 8 bytes long. If not, an error code will be returned. The key lpKey must be exactly 8 bytes long. The output array lpOutput must be at least nDataLen bytes long. lpOutput and lpData may be the same.

Example

This example uses a test vector from [FIPS 81].

    Dim nRet As Long
    Dim strInput As String
    Dim strKey As String
    Dim sCorrect As String
    Dim nKeyLen As Long
    Dim abKey() As Byte
    Dim lpOutput() As Byte
    Dim abData() As Byte
    Dim nDataLen As Long
    
    ' Define test vectors in hex
    strKey = "0123456789abcdef"
    strInput = "4e6f77206973207468652074696d6520666f7220616c6c20"
    sCorrect = "3FA40E8A984D48156A271787AB8883F9893D51EC4B563B53"
    
    ' Convert to byte arrays and compute lengths
    nKeyLen = Len(strKey) \ 2
    abKey = cnvBytesFromHexStr(strKey)
    nDataLen = Len(strInput) \ 2
    abData = cnvBytesFromHexStr(strInput)
    
    ' Dimension array for output
    ReDim lpOutput(nDataLen - 1)
    
    Debug.Print "KY=" & cnvHexStrFromBytes(abKey)
    Debug.Print "PT=" & cnvHexStrFromBytes(abData)
    ' Encrypt in one-off process
    nRet = DES_Bytes(lpOutput(0), abData(0), nDataLen, abKey(0), ENCRYPT)
    Debug.Print "CT=" & cnvHexStrFromBytes(lpOutput), nRet
    Debug.Print "OK=" & sCorrect
    Debug.Assert (sCorrect = cnvHexStrFromBytes(lpOutput))
    
    ' Now decrypt back
    nRet = DES_Bytes(abData(0), lpOutput(0), nDataLen, abKey(0), DECRYPT)
    Debug.Print "P'=" & cnvHexStrFromBytes(abData), nRet
    Debug.Assert (strInput = cnvHexStrFromBytes(abData))

This should result in output as follows:

KY=0123456789ABCDEF
PT=4E6F77206973207468652074696D6520666F7220616C6C20
CT=3FA40E8A984D48156A271787AB8883F9893D51EC4B563B53 0
OK=3FA40E8A984D48156A271787AB8883F9893D51EC4B563B53
P'=4E6F77206973207468652074696D6520666F7220616C6C20 0

See Also

DES_BytesMode

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