ocrypto_aes_cbc_pkcs_final_dec()

int ocrypto_aes_cbc_pkcs_final_dec	(	ocrypto_aes_cbc_pkcs_ctx *	ctx,
		uint8_t *	pt,
		size_t *	pt_len )

#include <crypto/nrf_oberon/include/ocrypto_aes_cbc_pkcs.h>

AES-CBC-PKCS7 final decryption output.

Parameters

	ctx	Context.
[out]	pt	Last part of the plaintext.
[out]	pt_len	Length of pt.

Return values

0	If the ciphertext input is properly padded.
-1	Otherwise.

Remarks

The total length of the ciphertext added before a call to this function must be non-zero and a multiple of 16.

The maximum length of pt is 15.

All clients, on all software layers, must ensure that the time for the operation is identical whether or not a padding error occurs. This is to prevent padding oracle attacks, a form of timing side- channel attacks. The provided implementation of this function does not leak timing information.