SignFinal

Synopsis

#include “fmciphobj.h”
int (*SignFinal)(struct CipherObj * ctx,
void * tgt, unsigned int tlength, unsigned int * plen);
 

Description

This function must be called to finish a signing or MAC operation. It can be used for either discovering the target buffer length, or for actually performing the operation.

If the target buffer address, tgt, is NULL, then the variable pointed to by plen is updated to contain the length of the output that is required to perform the operation.

If the target buffer address is not NULL, then the signing operation is completed, and the signature is placed in the output buffer.

Parameters

Parameter	Description
ctx	The address of a cipher object instance.
tgt	The address of the output buffer. It may be set to NULL for output buffer length estimation.
tlength	Total number of bytes available in the output buffer.
plen	Address of a variable that will receive the number of bytes placed in the target buffer. This variable must not be NULL.

Return Value

0: Operation completed successfully.

Otherwise: there was an error.

Comments

This function finalizes the signature context. SignInit() must be called again to sign more data, even when the key is the same.