tc_ctr_mode.c File Reference

#include "tc_constants.h"
#include "tc_ctr_mode.h"
#include "tc_utils.h"

Functions
int	tc_ctr_mode (uint8_t *out, unsigned int outlen, const uint8_t *in, unsigned int inlen, uint8_t *ctr, const TCAesKeySched_t sched)
	CTR mode encryption/decryption procedure. More...

Function Documentation

tc_ctr_mode()

int tc_ctr_mode	(	uint8_t *	out,
		unsigned int	outlen,
		const uint8_t *	in,
		unsigned int	inlen,
		uint8_t *	ctr,
		const TCAesKeySched_t	sched
	)

CTR mode encryption/decryption procedure.

CTR mode encrypts (or decrypts) inlen bytes from in buffer into out buffer

Returns

returns TC_CRYPTO_SUCCESS (1) returns TC_CRYPTO_FAIL (0) if: out == NULL or in == NULL or ctr == NULL or sched == NULL or inlen == 0 or outlen == 0 or inlen != outlen

Note

Assumes:- The current value in ctr has NOT been used with sched

• out points to inlen bytes
• in points to inlen bytes
• ctr is an integer counter in littleEndian format
• sched was initialized by aes_set_encrypt_key

Parameters

out	OUT – produced ciphertext (plaintext)
outlen	IN – length of ciphertext buffer in bytes
in	IN – data to encrypt (or decrypt)
inlen	IN – length of input data in bytes
ctr	IN/OUT – the current counter value
sched	IN – an initialized AES key schedule