BLF_BytesMode

BLF_BytesMode encrypts or decrypts an array of Bytes using a specified mode.

VB6/VBA Syntax

nRet = BLF_BytesMode(abOutput(0), abData(0), nDataLen, abKey(0), nKeyLen, bEncrypt, strMode, abInitV(0))

Parameters

abOutput

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

abData

[in] Byte array containing the input data.

nDataLen

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

abKey

[in] Byte array containing the key.

nKeyLen

[in] Long equal to length of the key in bytes.

bEncrypt

[in] Boolean direction flag: set as True to encrypt or False to decrypt.

strMode

[in] String specifying the confidentiality mode:
"ECB" for Electronic Codebook mode,
"CBC" for Cipher Block Chaining mode,
"CFB" for 64-bit Cipher Feedback mode,
"OFB" for Output Feedback mode, or
"CTR" for Counter mode.

abInitV

[in] Byte array containing the initialization vector (IV), or zero (0) for ECB mode.

C/C++ Syntax

Returns (VB6/C)

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

.NET Equivalent

Blowfish.Encrypt Method (Byte[], Byte[], Mode, Byte[])
Blowfish.Decrypt Method (Byte[], Byte[], Mode, Byte[])

Remarks

The input data abData must be an exact multiple of 8 bytes long. If not, an error code will be returned. The key abKey can be any length between 1 and 56 bytes. The output array abOutput must be at least nDataLen bytes long. abOutput and abData may be the same. Note the (0) after the byte array variables.

Example

    Dim nRet As Long
    Dim strOutput As String
    Dim strInput As String
    Dim strKey As String
    Dim strHexIV As String
    Dim sCorrect As String
    Dim nKeyLen As Long
    Dim abKey() As Byte
    Dim abOutput() As Byte
    Dim abData() As Byte
    Dim nDataLen As Long
    Dim abInitV() As Byte
    Dim nIVLen As Long
    
    strKey = "0123456789ABCDEFF0E1D2C3B4A59687"
    strHexIV = "FEDCBA9876543210"
    strInput = _
"37363534333231204E6F77206973207468652074696D6520666F722000000000"
    sCorrect = _
"6B77B4D63006DEE605B156E27403979358DEB9E7154616D959F1652BD5FF92CC"
    
    ' Convert to byte arrays and compute lengths
    nKeyLen = Len(strKey) \ 2
    nDataLen = Len(strInput) \ 2
    nIVLen = Len(strHexIV) \ 2
    abKey = cnvBytesFromHexStr(strKey)
    abData = cnvBytesFromHexStr(strInput)
    abInitV = cnvBytesFromHexStr(strHexIV)
    
    ' Dimension array for output
    ReDim abOutput(nDataLen - 1)
    
    Debug.Print "KY="; cnvHexStrFromBytes(abKey)
    Debug.Print "IV="; cnvHexStrFromBytes(abInitV)
    Debug.Print "PT="; cnvHexStrFromBytes(abData)
    ' Encrypt in one-off process
    nRet = BLF_BytesMode(abOutput(0), abData(0), nDataLen, abKey(0), _
        nKeyLen, ENCRYPT, "CBC", abInitV(0))
    Debug.Print "CT="; cnvHexStrFromBytes(abOutput), nRet
    Debug.Print "OK="; sCorrect
    
    ' Now decrypt back
    nRet = BLF_BytesMode(abData(0), abOutput(0), nDataLen, abKey(0), _
        nKeyLen, DECRYPT, "cbc", abInitV(0))
    Debug.Print "P'="; cnvHexStrFromBytes(abData), nRet

This should result in output as follows:

KY=0123456789ABCDEFF0E1D2C3B4A59687
IV=FEDCBA9876543210
PT=37363534333231204E6F77206973207468652074696D6520666F722000000000
CT=6B77B4D63006DEE605B156E27403979358DEB9E7154616D959F1652BD5FF92CC    0 
OK=6B77B4D63006DEE605B156E27403979358DEB9E7154616D959F1652BD5FF92CC
P'=37363534333231204E6F77206973207468652074696D6520666F722000000000    0 

See Also

BLF_Bytes

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