/**
* @brief Secure one block with CCM*
*
* This functions secures one block with CCM* according to 802.15.4.
*
* @param[in,out] buffer Input: plaintext header and payload concatenated;
* for encryption: MUST HAVE 'AES_BLOCKSIZE'
* BYTES SPACE AT THE END FOR THE MIC!
* Output: frame secured (with MIC at end)/unsecured
* @param[in] nonce The nonce: Initialization Vector (IV) as used in
* cryptography; the ZigBee nonce (13 bytes long)
* are the bytes 2...14 of this nonce
* @param[in] key The key to be used; if NULL, use the current key
* @param[in] hdr_len Length of plaintext header (will not be encrypted)
* @param[in] pld_len Length of payload to be encrypted; if 0, then only MIC
* authentication implies
* @param[in] sec_level Security level according to IEEE 802.15.4,
* 7.6.2.2.1, Table 95:
* - the value may be 0 ... 7;
* - the two LSBs contain the MIC length in bytes
* (0, 4, 8 or 16);
* - bit 2 indicates whether encryption applies or not
* @param[in] aes_dir AES_DIR_ENCRYPT if secure, AES_DIR_DECRYPT if unsecure
*
* @return STB CCM Status
*/
stb_ccm_t stb_ccm_secure(uint8_t *buffer,
uint8_t nonce[AES_BLOCKSIZE],
uint8_t *key,
uint8_t hdr_len,
uint8_t pld_len,
uint8_t sec_level,
uint8_t aes_dir)
{
uint8_t nonce_0; /* nonce[0] for MIC computation. */
uint8_t mic_len;
uint8_t enc_flag;
if (stb_restart_required)
{
sal_aes_restart();
stb_restart_required = false;
}
if (sec_level & 3)
{
mic_len = 1 << ((sec_level & 3) + 1);
}
else
{
mic_len = 0;
}
enc_flag = sec_level & 4;
/* Test on correct parameters. */
if ((sec_level & ~0x7) ||
(buffer == NULL) ||
(nonce == NULL) ||
((uint16_t)pld_len + (uint16_t)hdr_len + (uint16_t)mic_len > aMaxPHYPacketSize)
)
{
sal_aes_clean_up();
return (STB_CCM_ILLPARM);
}
if (key_change && (key == NULL))
{
sal_aes_clean_up();
return (STB_CCM_KEYMISS); /* Initial call, but no key given. */
}
/* Setup key if necessary. */
if(!key_change && key != NULL) /* There was some previous key. */
{
uint8_t i;
/* Test on changed key. */
for (i = AES_BLOCKSIZE; i--; /* */)
{
key_change |= (last_key[i] ^ key[i]);
}
}
if (key_change)
{
/*
* Key must be non-NULL because of test above, and
* ECB encryption is always the initial encryption mode.
*/
sal_aes_setup(key, AES_MODE_ECB, AES_DIR_ENCRYPT);
memcpy(last_key, key, AES_KEYSIZE);
key_change = false;
}
/* Prepare nonce. */
nonce[0] = 1; /* Always 2 bytes for length field. */
if (mic_len > 0)
{
nonce[0] |= ((mic_len - 2) >> 1) << 3;
}
/**
* @brief Secure one block with CCM*
*
* This functions secures one block with CCM* according to 802.15.4.
*
* @param[in,out] buffer Input: plaintext header and payload concatenated;
* for encryption: MUST HAVE 'AES_BLOCKSIZE'
* BYTES SPACE AT THE END FOR THE MIC!
* Output: frame secured (with MIC at end)/unsecured
* @param[in] nonce The nonce: Initialization Vector (IV) as used in
* cryptography; the ZigBee nonce (13 bytes long)
* are the bytes 2...14 of this nonce
* @param[in] key The key to be used; if NULL, use the current key
* @param[in] hdr_len Length of plain text header (will not be encrypted)
* @param[in] pld_len Length of payload to be encrypted; if 0, then only MIC
* authentication implies
* @param[in] sec_level Security level according to IEEE 802.15.4,
* 7.6.2.2.1, Table 95:
* - the value may be 0 ... 7;
* - the two LSBs contain the MIC length in bytes
* (0, 4, 8 or 16);
* - bit 2 indicates whether encryption applies or not
* @param[in] aes_dir AES_DIR_ENCRYPT if secure, AES_DIR_DECRYPT if unsecured
*
* @return STB CCM Status
*/
stb_ccm_t stb_ccm_secure(uint8_t *buffer,
uint8_t nonce[AES_BLOCKSIZE],
uint8_t *key,
uint8_t hdr_len,
uint8_t pld_len,
uint8_t sec_level,
uint8_t aes_dir)
{
uint8_t nonce_0; /* nonce[0] for MIC computation. */
uint8_t mic_len = 0;
uint8_t enc_flag = ENCRYPTION_NOT_REQD;
if (stb_restart_required) {
#if (SAL_TYPE != ATXMEGA_SAL)
prev_trx_status = tal_trx_status;
if (tal_trx_status == TRX_SLEEP) {
tal_trx_wakeup();
}
#endif
sal_aes_restart();
stb_restart_required = false;
}
switch (sec_level) {
case SECURITY_00_LEVEL:
/* No MIC & No Encryption at Security Level -0 */
mic_len = LEN_MIC_00;
break;
case SECURITY_01_LEVEL:
/* MIC-32 & No Encryption at Security Level -1 */
mic_len = LEN_MIC_32;
break;
case SECURITY_02_LEVEL:
/* MIC-64 & No Encryption at Security Level -2 */
mic_len = LEN_MIC_64;
break;
case SECURITY_03_LEVEL:
/* MIC-128 & No Encryption at Security Level -3 */
mic_len = LEN_MIC_128;
break;
case SECURITY_04_LEVEL:
/* No MIC & Encryption at Security Level -4 */
mic_len = LEN_MIC_00;
enc_flag = ENCRYPTION_REQD;
break;
case SECURITY_05_LEVEL:
/* MIC-32 & Encryption at Security Level -5 */
mic_len = LEN_MIC_32;
enc_flag = ENCRYPTION_REQD;
break;
case SECURITY_06_LEVEL:
/* MIC-64 & Encryption at Security Level -6 */
mic_len = LEN_MIC_64;
enc_flag = ENCRYPTION_REQD;
break;
case SECURITY_07_LEVEL:
/* MIC-128 & Encryption at Security Level -7 */
mic_len = LEN_MIC_128;
enc_flag = ENCRYPTION_REQD;
break;
default:
break;
}
/* Test on correct parameters. */
if ((sec_level & ~0x7) ||
(buffer == NULL) ||
(nonce == NULL) ||
((uint16_t)pld_len + (uint16_t)hdr_len +
(uint16_t)mic_len > aMaxPHYPacketSize)
) {
#if (SAL_TYPE != ATXMEGA_SAL)
TRX_SLEEP();
sal_aes_clean_up();
#endif
return (STB_CCM_ILLPARM);
}
if (key_change && (key == NULL)) {
#if (SAL_TYPE != ATXMEGA_SAL)
TRX_SLEEP();
sal_aes_clean_up();
#endif
/* Initial call, but no key given. */
return (STB_CCM_KEYMISS);
}
/* Setup key if necessary. */
if (!key_change && key != NULL) { /* There was some previous key. */
uint8_t i;
/* Test on changed key. */
for (i = AES_BLOCKSIZE; i--; /* */) {
key_change |= (last_key[i] ^ key[i]);
}
}
if (key_change) {
/*
* Key must be non-NULL because of test above, and
* ECB encryption is always the initial encryption mode.
*/
sal_aes_setup(key, AES_MODE_ECB, AES_DIR_ENCRYPT);
memcpy(last_key, key, AES_KEYSIZE);
key_change = false;
}
/* Prepare nonce. */
nonce[0] = LEN_FIELD; /* Always 2 bytes for length field. */
if (mic_len > 0) {
nonce[0] |= (uint8_t)(((mic_len - 2) >> 1) << 3);
}
