DecryptUpdate Method

Decrypts the next block of encrypted data.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
char* DecryptUpdate(const char* lpBuffer, int lenBuffer, int *lpSize = NULL);

Unicode (Windows)
LPSTR DecryptUpdate(LPCSTR lpBuffer, INT lenBuffer, LPINT lpSize = NULL);

- (NSData*)decryptUpdate:(NSData*)buffer;

#define MID_SYMMETRICCRYPTO_DECRYPTUPDATE 8

SECUREBLACKBOX_EXTERNAL int SECUREBLACKBOX_CALL SecureBlackbox_SymmetricCrypto_Do(void *lpObj, int methid, int cparam, void *param[], int cbparam[], int64 *lpllVal);

Remarks

When using block-by-block decryption, pass every subsequent block of the encryptedmessage to this method until the entire message is processed. For each encryptedblock the method returns a piece of decrypted data.

Please note that in general case there is no direct correspondence between the data actuallycontained in the encrypted block with the output of this method. The component maychoose to cache a piece of the provided buffer internally if it doesn't constitutea full block of encrypted data.

Remember to call DecryptInit before calling this method to prepare the controlfor the decryption process.

Error Handling (C++)

This method returns a Byte Array value (with length lpSize); after it returns, call the GetLastErrorCode() method to obtain its result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.