Function Context Structures¶
Some Intel IPP Cryptography functions use special structures to store
function-specific (context) information. For example, the
IppsRijndael128Spec structure stores a set of round keys, a set of round
inverse keys, and key management information for the Rijndael cipher
scheme with the block size equal to 128.
Two different kinds of context structures are used:
Specification structures, which are not modified during the function’s operation. Their names include the
Specsuffix.State structures, which are modified during operation. Their names include the
Statesuffix.
Note
Important
It is your application that defines the life cycle of the context: initialization, updating, and destruction.
Each type of context is initialized with the specific initialization
function. For example, the ippsAESInit function initializes the
user-supplied memory as the IppsAESState context.
Note
Important
Your application must exclusively pass the address of the original
(initialized by the suitable Init function) context to an Intel IPP
function.
Simple copying of the context (for example, using memcpy()) and
passing the address of this copy instead of the address of the
original context to an Intel IPP call may lead to misinterpretation
inside the library function.