RadioLibAES128 Class Reference

Class to perform AES encryption, decryption and CMAC. More...

#include <Cryptography.h>

Public Member Functions
	RadioLibAES128 ()
	Default constructor.
void	init (uint8_t *key)
	Initialize the AES.
size_t	encryptECB (const uint8_t *in, size_t len, uint8_t *out)
	Perform ECB-type AES encryption.
size_t	decryptECB (const uint8_t *in, size_t len, uint8_t *out)
	Perform ECB-type AES decryption.
void	generateCMAC (const uint8_t *in, size_t len, uint8_t *cmac)
	Calculate message authentication code according to RFC4493.
void	initCMAC (RadioLibCmacState *st)
	Initialize the CMAC state. This must be called before any updateCMAC calls.
void	updateCMAC (RadioLibCmacState *st, const uint8_t *data, size_t len)
	Update the CMAC state with a chunk of data. This can be called multiple times to process the data in chunks.
void	finishCMAC (RadioLibCmacState *st, uint8_t *out)
	Finalize the CMAC calculation and save the result. This must be called after all updateCMAC calls are done.
bool	verifyCMAC (const uint8_t *in, size_t len, const uint8_t *cmac)
	Verify the received CMAC. This just calculates the CMAC again and compares the results.

Detailed Description

Class to perform AES encryption, decryption and CMAC.

Most of the implementation here is adapted from https://github.com/kokke/tiny-AES-c Additional code and CMAC calculation is from https://github.com/megrxu/AES-CMAC

Member Function Documentation

decryptECB()

size_t RadioLibAES128::decryptECB	(	const uint8_t *	in,
		size_t	len,
		uint8_t *	out
	)

Perform ECB-type AES decryption.

Parameters

in	Input ciphertext data.
len	Length of the input data.
out	Buffer to save the output plaintext into. It is up to the caller to ensure the buffer is sufficiently large to save the data!

Returns

The number of bytes saved into the output buffer.

encryptECB()

size_t RadioLibAES128::encryptECB	(	const uint8_t *	in,
		size_t	len,
		uint8_t *	out
	)

Perform ECB-type AES encryption.

Parameters

in	Input plaintext data (unpadded).
len	Length of the input data.
out	Buffer to save the output ciphertext into. It is up to the caller to ensure the buffer is sufficiently large to save the data!

Returns

The number of bytes saved into the output buffer.

finishCMAC()

void RadioLibAES128::finishCMAC	(	RadioLibCmacState *	st,
		uint8_t *	out
	)

Finalize the CMAC calculation and save the result. This must be called after all updateCMAC calls are done.

Parameters

st	State to finalize.
out	Buffer to save the output MAC into. The buffer must be at least 16 bytes long!

generateCMAC()

void RadioLibAES128::generateCMAC	(	const uint8_t *	in,
		size_t	len,
		uint8_t *	cmac
	)

Calculate message authentication code according to RFC4493.

Parameters

in	Input data (unpadded).
len	Length of the input data.
cmac	Buffer to save the output MAC into. The buffer must be at least 16 bytes long!

init()

void RadioLibAES128::init

(

uint8_t *

key

)

Initialize the AES.

Parameters

key	AES key to use.

initCMAC()

void RadioLibAES128::initCMAC

(

RadioLibCmacState *

st

)

Initialize the CMAC state. This must be called before any updateCMAC calls.

Parameters

st	State to initialize.

updateCMAC()

void RadioLibAES128::updateCMAC	(	RadioLibCmacState *	st,
		const uint8_t *	data,
		size_t	len
	)

Update the CMAC state with a chunk of data. This can be called multiple times to process the data in chunks.

Parameters

st	State to update.
data	Input data (unpadded).
len	Length of the input data.

verifyCMAC()

bool RadioLibAES128::verifyCMAC	(	const uint8_t *	in,
		size_t	len,
		const uint8_t *	cmac
	)

Verify the received CMAC. This just calculates the CMAC again and compares the results.

Parameters

in	Input data (unpadded).
len	Length of the input data.
cmac	CMAC to verify.

Returns

True if valid, false otherwise.

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The documentation for this class was generated from the following files:

• src/utils/Cryptography.h
• src/utils/Cryptography.cpp