AES256_Init

CryptoSys API Library Manual

AES256_Init

Initialises the context with the key, direction and mode ready for repeated operations of the AES function. The key and IV data are in byte arrays.

VBA/VB6 Syntax


Public Declare Function AES256_Init Lib "diCryptoSys.dll"
    (ByRef lpKey As Byte, 
    ByVal bEncrypt As Boolean, ByVal strMode As String, ByRef lpInitV As Byte) As Long

hContext = AES256_Init(abKey(0), bEncrypt, strMode, abInitV(0))

C/C++ Syntax


long __stdcall  AES256_Init(const unsigned char *lpKey, int fEncrypt, const char *szMode, const unsigned char *lpIV);

Parameters

lpKey: [in] array containing the key.
fEncrypt: [in] direction flag: set as ENCRYPT (True) to encrypt or DECRYPT (False) to decrypt.
szMode: [in] specifying the confidentiality mode:
"ECB" for Electronic Codebook mode,
"CBC" for Cipher Block Chaining mode,
"CFB" for 128-bit Cipher Feedback mode,
"OFB" for Output Feedback mode, or
"CTR" for Counter mode.
lpIV: [in] array containing the initialization vector, or zero (0) for ECB mode.

Returns (VBA/C)

Non-zero handle of the context hContext to be used in subsequent calls to the functions AES256_Update, AES256_UpdateHex or AES256_Final. Returns zero if an error occurs.

.NET Equivalent

Aes256.InitEncrypt Method (Byte[], Mode, Byte[])
Aes256.InitDecrypt Method (Byte[], Mode, Byte[])

Remarks

The key array abKey() must be exactly 32 bytes long (i.e. 256 bits). The initialization vector abInitV() must be exactly the block size of 16 bytes long, except for ECB mode, where it is ignored (use 0). Unlike most other functions in this API, AES256_Init returns zero if an error occurs. It is important to check that the value of hContext returned is not equal to zero before calling the AES Update function.

Example

See AES256_Update.

AES256_Init

VBA/VB6 Syntax

C/C++ Syntax

Parameters

Returns (VBA/C)

.NET Equivalent

Remarks

Example

See Also