Developer Guide and Reference for Intel® Integrated Performance Primitives Cryptography
GFpECESFinal_SM2
Completes the ECES SM2 encryption or decryption chain.
Syntax
IppStatus ippsGFpECESFinal_SM2(Ipp8u* pTag, int tagLen, ippsECES_StateSM2* pState);
Include Files
ippcp.h
Parameters
| pTag | Pointer to the tag buffer. | 
| tagLen | Requested length of the authentication tag. | 
| pState | Pointer to the buffer being initialized as the ECES context. | 
Description
The function completes the Elliptic Curve Encryption Scheme (ECES) SM2 algorithm and returns the computed authentication tag.
Return Values
| ippStsNoErr | Indicates no error. Any other value indicates an error or warning. | 
| ippStsNullPtrErr | Indicates an error condition if any of the specified pointers is NULL. | 
| ippStsContextMatchErr | Indicates an error condition if the IppsECES_StateSM2 context parameter does not match the operation. | 
| ippStsSizeErr | Indicates an error condition if tagLen<0 or tagLen>32. | 
| ippStsShareKeyErr | Indicates an error condition if all generated key gammas were zeros in the encryption or decryption steps. |