stb_internal.h File Reference

Declarations for security tool box.

Copyright (c) 2014-2018 Microchip Technology Inc. and its subsidiaries.

Functions
void	compute_mic (uint8_t *buffer, uint8_t *mic, uint8_t *nonce, uint8_t hdr_len, uint8_t pld_len)
	Computes MIC. More...
void	encrypt_pldmic (uint8_t *buffer, uint8_t *nonce, uint8_t mic_len, uint8_t pld_len)
	Encrypts and decrypts payload and MIC. More...
void	encrypt_with_padding (uint8_t *start, uint8_t buflen)
	CBC Encrypt data stream with null padding at the end. More...

void compute_mic	(	uint8_t *	buffer,
		uint8_t *	mic,
		uint8_t *	nonce,
		uint8_t	hdr_len,
		uint8_t	pld_len
	)

Computes MIC.

This function computes the MIC according to CCM.

The key was initialized in other functions before.

Parameters

[in]	buffer	Input data (frame, not padded yet)
[out]	mic	Computed MIC of size AES_BLOCKSIZE
[in]	nonce	The nonce: Initialization Vector (IV) as used in cryptography; the ZigBee nonce are the bytes 2...14 of this nonce
[in]	hdr_len	Size of plain text header in bytes (may be 0)
[in]	pld_len	Length of payload in bytes (may be 0)

References AES_BLOCKSIZE, AES_DIR_ENCRYPT, AES_MODE_CBC, AES_MODE_ECB, encrypt_with_padding(), MIN, sal_aes_exec(), sal_aes_read(), sal_aes_setup(), and sal_aes_wrrd().

Referenced by stb_ccm_secure().

void encrypt_pldmic	(	uint8_t *	buffer,
		uint8_t *	nonce,
		uint8_t	mic_len,
		uint8_t	pld_len
	)

Encrypts and decrypts payload and MIC.

This function perform encryption and decryption of the payload and the MIC.

Parameters

[in]	buffer	Input data (frame, not padded yet)
[in]	nonce	The nonce
[in]	mic_len	Size of MIC in bytes (may be 0)
[in]	pld_len	Length of payload in bytes (may be 0)

References AES_BLOCKSIZE, AES_DIR_ENCRYPT, AES_MODE_ECB, MIN, sal_aes_read(), sal_aes_setup(), and sal_aes_wrrd().

Referenced by stb_ccm_secure().

void encrypt_with_padding	(	uint8_t *	start,
		uint8_t	buflen
	)

CBC Encrypt data stream with null padding at the end.

This function preforms CBC Encryption in the actual mode with actual key and portions of AES_BLOCKSIZE length. If the last block has less than AES_BLOCKSIZE bytes, it is padded with null bytes to this length and then encrypted.

No result is return; the CBC-MAC must be read separately.

Parameters

start	Pointer to start address
buflen	Number of bytes to be encrypted; if 0, nothing happens

References AES_BLOCKSIZE, sal_aes_exec(), and sal_aes_wrrd().

Referenced by compute_mic().