Rijndael128GCMGetSizeManaged

Gets the size of the IppsRijndael128GCMState context for use of the AES-GCM implementation with the specified characteristics.

Syntax

IppStatus ippsRijndael128GCMGetSizeManaged(IppAESGCMbehaviour flag, Ipp32u* pSize);

Parameters

flag	A flag that defines characteristics of the AES-GCM implementation.
pSize	Pointer to the size of the IppsRijndael128GCMState context.

Description

This function is declared in the ippcp.h file. The function takes characteristics of the AES-GCM implementation from the input parameter flag, gets the size of the IppsRijndael128GCMState context (in bytes) needed to perform encryption and/or decryption that uses the specified AES-GCM implementation, and stores the size in *pSize. The flag parameter is the following enumerator:

typedef enum {
    ippAESGCMdefault,
    ippAESGCMsafe,
    ippAESGCMtable2K
}
IppAESGCMbehaviour;

where the values define the following requirements for the characteristics of the AES-GCM implementation:

ippAESGCMdefault	Minimum memory, that is, the minimum size of the context
ippAESGCMsafe	Maximum protection against timing attacks
ippAESGCMtable2K	Maximum performance of the implementation

Note

If your system is based on microprocessors that support an AES instruction set, the AES-GCM implementation will meet all the above requirements regardless of the value of flag.

Optimization Notice
The Intel® Integrated Performance Primitives (Intel® IPP) library contains functions that are more highly optimized for Intel microprocessors than for other microprocessors. While the functions in the Intel® IPP library offer optimizations for both Intel and Intel-compatible microprocessors, depending on your code and other factors, you will likely get extra performance on Intel microprocessors. While the paragraph above describes the basic optimization approach for the Intel® IPP library as a whole, the library may or may not be optimized to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include Intel® Streaming SIMD Extensions 2 (Intel® SSE2), Intel® Streaming SIMD Extensions 3 (Intel® SSE3), and Supplemental Streaming SIMD Extensions 3 (Intel® SSSE3) instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Intel recommends that you evaluate other library products to determine which best meets your requirements.

Optimization Notice

The Intel® Integrated Performance Primitives (Intel® IPP) library contains functions that are more highly optimized for Intel microprocessors than for other microprocessors. While the functions in the Intel® IPP library offer optimizations for both Intel and Intel-compatible microprocessors, depending on your code and other factors, you will likely get extra performance on Intel microprocessors.

While the paragraph above describes the basic optimization approach for the Intel® IPP library as a whole, the library may or may not be optimized to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include Intel® Streaming SIMD Extensions 2 (Intel® SSE2), Intel® Streaming SIMD Extensions 3 (Intel® SSE3), and Supplemental Streaming SIMD Extensions 3 (Intel® SSSE3) instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors.

Intel recommends that you evaluate other library products to determine which best meets your requirements.

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error or warning.
ippStsNullPtrErr	Indicates an error condition if the specified pointer is NULL.