PSA_BLOCK_CIPHER_BLOCK_LENGTH macro

The block size of a block cipher. \warning This macro may evaluate its argument multiple times.

Syntax

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Summary

Declaration

from crypto_values.h:764

#define PSA_BLOCK_CIPHER_BLOCK_LENGTH(type) \ (((type) & PSA_KEY_TYPE_CATEGORY_MASK) == PSA_KEY_TYPE_CATEGORY_SYMMETRIC ? \ 1u << PSA_GET_KEY_TYPE_BLOCK_SIZE_EXPONENT(type) : \ 0u)

Arguments

Argument

Description

type

A cipher key type (value of type #psa_key_type_t).

Return value

The block size for a block cipher, or 1 for a stream cipher. The return value is undefined if \p type is not a supported cipher key type.

Notes

It is possible to build stream cipher algorithms on top of a block cipher, for example CTR mode (#PSA_ALG_CTR). This macro only takes the key type into account, so it cannot be used to determine the size of the data that #psa_cipher_update() might buffer for future processing in general. This macro returns a compile-time constant if its argument is one.