TDEA_Bytes encrypts or decrypts an array of Bytes
in one step in Electronic Codebook (EBC) mode.
Public Declare Function TDEA_Bytes Lib "diCryptoSys.dll"
(ByRef abOutput As Byte, ByRef abData As Byte, ByVal nDataLen As Long,
ByRef abKey As Byte, ByVal bEncrypt As Boolean) As Long
nRet = TDEA_Bytes(abOutput(0), abData(0), nDataLen, abKey(0), bEncrypt)
Byte array of sufficient length to receive the output.Byte array containing the input data.Long equal to length of the input data in bytes.Byte array containing the key.Boolean direction flag:
set as True to encrypt or False
to decrypt.
long _stdcall TDEA_Bytes(unsigned char *output, const unsigned char *input,
long nbytes, const unsigned char *key, int bEncrypt);
Long: If successful, the return value is 0;
otherwise it returns a non-zero error code.
The input data abData must be an exact multiple of 8 bytes long. If not, an error code will be returned. The key abKey must be exactly 24 bytes long. 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.
Dim nRet As Long
Dim strInput As String
Dim strKey As String
Dim sCorrect As String
Dim abKey() As Byte
Dim abOutput() As Byte
Dim abData() As Byte
Dim nDataLen As Long
' Define test vectors in hex
strKey = "0123456789abcdeffedcba987654321089abcdef01234567"
strInput = "0123456789abcde70123456789abcde7"
sCorrect = "de0b7c06ae5e0ed5de0b7c06ae5e0ed5"
' Convert to byte arrays and compute lengths
abKey = cnvBytesFromHexStr(strKey)
abData = cnvBytesFromHexStr(strInput)
nDataLen = Len(strInput) \ 2
' Dimension array for output
ReDim abOutput(nDataLen - 1)
Debug.Print "KY="; cnvHexStrFromBytes(abKey)
Debug.Print "PT="; cnvHexStrFromBytes(abData)
' Encrypt in one-off process
nRet = TDEA_Bytes(abOutput(0), abData(0), nDataLen, abKey(0), ENCRYPT)
Debug.Print "CT="; cnvHexStrFromBytes(abOutput), nRet
Debug.Print "OK="; sCorrect
Debug.Assert (sCorrect = cnvHexStrFromBytes(abOutput))
' Now decrypt back
nRet = TDEA_Bytes(abData(0), abOutput(0), nDataLen, abKey(0), DECRYPT)
Debug.Print "P'="; cnvHexStrFromBytes(abData), nRet
Debug.Assert (strInput = cnvHexStrFromBytes(abData))
This should result in output as follows:
KY=0123456789ABCDEFFEDCBA987654321089ABCDEF01234567 PT=0123456789ABCDE70123456789ABCDE7 CT=DE0B7C06AE5E0ED5DE0B7C06AE5E0ED5 0 OK=de0b7c06ae5e0ed5de0b7c06ae5e0ed5 P'=0123456789ABCDE70123456789ABCDE7 0