The single block cipher API is used with the ciphers of type CRYPTO_ALG_TYPE_CIPHER (listed as type “cipher” in /proc/crypto).

Using the single block cipher API calls, operations with the basic cipher primitive can be implemented. These cipher primitives exclude any block chaining operations including IV handling.

The purpose of this single block cipher API is to support the implementation of templates or other concepts that only need to perform the cipher operation on one block at a time. Templates invoke the underlying cipher primitive block-wise and process either the input or the output data of these cipher operations.