generalised CCM module into lib

introduced convenience functions for LLSEC modules
This commit is contained in:
Justin King-Lacroix 2015-06-08 19:06:40 +01:00
parent 06f7acfd5b
commit 3ce8f26eea
7 changed files with 159 additions and 102 deletions

View File

@ -34,44 +34,41 @@
* \file
* AES_128-based CCM* implementation.
* \author
* Konrad Krentz <konrad.krentz@gmail.com>
* Original: Konrad Krentz <konrad.krentz@gmail.com>
* Generified version: Justin King-Lacroix <justin.kinglacroix@gmail.com>
*/
/**
* \addtogroup llsec802154
* @{
*/
#include "net/llsec/ccm-star.h"
#include "net/llsec/llsec802154.h"
#include "net/packetbuf.h"
#include "ccm-star.h"
#include "lib/aes-128.h"
#include <string.h>
/* see RFC 3610 */
#define CCM_STAR_AUTH_FLAGS(Adata, M) ((Adata ? (1u << 6) : 0) | (((M - 2u) >> 1) << 3) | 1u)
#define CCM_STAR_ENCRYPTION_FLAGS 1
#define CCM_STAR_NONCE_MAX_IV_LENGTH 13
/*---------------------------------------------------------------------------*/
static void
set_nonce(uint8_t *nonce,
uint8_t flags,
const uint8_t *extended_source_address,
const uint8_t *iv, uint8_t iv_len,
uint8_t counter)
{
/* 1 byte|| 8 bytes || 4 bytes || 1 byte || 2 bytes */
/* flags || extended_source_address || frame_counter || sec_lvl || counter */
if(iv_len > CCM_STAR_NONCE_MAX_IV_LENGTH)
iv_len = CCM_STAR_NONCE_MAX_IV_LENGTH;
nonce[0] = flags;
memcpy(nonce + 1, extended_source_address, 8);
nonce[9] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) >> 8;
nonce[10] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) & 0xff;
nonce[11] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) >> 8;
nonce[12] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) & 0xff;
nonce[13] = packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL);
nonce[14] = 0;
memcpy(nonce + 1, iv, iv_len);
memset(nonce + iv_len + 1, 0, 16 - (1 + 1 + iv_len));
nonce[15] = counter;
}
/*---------------------------------------------------------------------------*/
/* XORs the block m[pos] ... m[pos + 15] with K_{counter} */
static void
ctr_step(const uint8_t *extended_source_address,
ctr_step(const uint8_t *iv, uint8_t iv_len,
uint8_t pos,
uint8_t *m_and_result,
uint8_t m_len,
@ -80,7 +77,7 @@ ctr_step(const uint8_t *extended_source_address,
uint8_t a[AES_128_BLOCK_SIZE];
uint8_t i;
set_nonce(a, CCM_STAR_ENCRYPTION_FLAGS, extended_source_address, counter);
set_nonce(a, CCM_STAR_ENCRYPTION_FLAGS, iv, iv_len, counter);
AES_128.encrypt(a);
for(i = 0; (pos + i < m_len) && (i < AES_128_BLOCK_SIZE); i++) {
@ -89,43 +86,23 @@ ctr_step(const uint8_t *extended_source_address,
}
/*---------------------------------------------------------------------------*/
static void
mic(const uint8_t *extended_source_address,
mic(const uint8_t* m, uint8_t m_len,
const uint8_t* iv, uint8_t iv_len,
const uint8_t* a, uint8_t a_len,
uint8_t *result,
uint8_t mic_len)
{
uint8_t x[AES_128_BLOCK_SIZE];
uint8_t pos;
uint8_t i;
uint8_t a_len;
uint8_t *a;
#if LLSEC802154_USES_ENCRYPTION
uint8_t shall_encrypt;
uint8_t m_len;
uint8_t *m;
shall_encrypt = packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL) & (1 << 2);
if(shall_encrypt) {
a_len = packetbuf_hdrlen();
m_len = packetbuf_datalen();
} else {
a_len = packetbuf_totlen();
m_len = 0;
}
set_nonce(x,
CCM_STAR_AUTH_FLAGS(a_len, mic_len),
extended_source_address,
iv, iv_len,
m_len);
#else /* LLSEC802154_USES_ENCRYPTION */
a_len = packetbuf_totlen();
set_nonce(x,
CCM_STAR_AUTH_FLAGS(a_len, mic_len),
extended_source_address,
0);
#endif /* LLSEC802154_USES_ENCRYPTION */
AES_128.encrypt(x);
a = packetbuf_hdrptr();
if(a_len) {
if(a_len > 0) {
x[1] = x[1] ^ a_len;
for(i = 2; (i - 2 < a_len) && (i < AES_128_BLOCK_SIZE); i++) {
x[i] ^= a[i - 2];
@ -143,8 +120,7 @@ mic(const uint8_t *extended_source_address,
}
}
#if LLSEC802154_USES_ENCRYPTION
if(shall_encrypt) {
if(m_len > 0) {
m = a + a_len;
pos = 0;
while(pos < m_len) {
@ -155,36 +131,33 @@ mic(const uint8_t *extended_source_address,
AES_128.encrypt(x);
}
}
#endif /* LLSEC802154_USES_ENCRYPTION */
ctr_step(extended_source_address, 0, x, AES_128_BLOCK_SIZE, 0);
ctr_step(iv, iv_len, 0, x, AES_128_BLOCK_SIZE, 0);
memcpy(result, x, mic_len);
}
/*---------------------------------------------------------------------------*/
static void
ctr(const uint8_t *extended_source_address)
ctr(uint8_t* m, uint8_t m_len, const uint8_t* iv, uint8_t iv_len)
{
uint8_t m_len;
uint8_t *m;
uint8_t pos;
uint8_t counter;
m_len = packetbuf_datalen();
m = (uint8_t *) packetbuf_dataptr();
pos = 0;
counter = 1;
while(pos < m_len) {
ctr_step(extended_source_address, pos, m, m_len, counter++);
ctr_step(iv, iv_len, pos, m, m_len, counter++);
pos += AES_128_BLOCK_SIZE;
}
}
/*---------------------------------------------------------------------------*/
static void set_key(const uint8_t* key) {
AES_128.set_key((uint8_t*)key);
}
/*---------------------------------------------------------------------------*/
const struct ccm_star_driver ccm_star_driver = {
mic,
ctr
ctr,
set_key
};
/*---------------------------------------------------------------------------*/
/** @} */

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@ -34,23 +34,13 @@
* \file
* CCM* header file.
* \author
* Konrad Krentz <konrad.krentz@gmail.com>
* Original: Konrad Krentz <konrad.krentz@gmail.com>
* Generified version: Justin King-Lacroix <justin.kinglacroix@gmail.com>
*/
/**
* \addtogroup llsec802154
* @{
*/
#ifndef CCM_STAR_H_
#define CCM_STAR_H_
#include "contiki.h"
#include "net/mac/frame802154.h"
/* see RFC 3610 */
#define CCM_STAR_AUTH_FLAGS(Adata, M) ((Adata ? (1 << 6) : 0) | (((M - 2) >> 1) << 3) | 1)
#define CCM_STAR_ENCRYPTION_FLAGS 1
#ifdef CCM_STAR_CONF
#define CCM_STAR CCM_STAR_CONF
@ -64,22 +54,39 @@
struct ccm_star_driver {
/**
* \brief Generates a MIC over the frame in the packetbuf.
* \brief Generates a MIC over the data supplied.
* \param data The data buffer to read.
* \param data_length The data buffer length.
* \param iv The IV to use.
* \param iv_length The IV's length.
* \param result The generated MIC will be put here
* \param mic_len <= 16; set to LLSEC802154_MIC_LENGTH to be compliant
* \param mic_len The size of the MIC to be generated. <= 16.
*/
void (* mic)(const uint8_t *extended_source_address,
void (* mic)(const uint8_t* data, uint8_t data_length,
const uint8_t* iv, uint8_t iv_len,
const uint8_t* add, uint8_t add_len,
uint8_t *result,
uint8_t mic_len);
/**
* \brief XORs the frame in the packetbuf with the key stream.
* \param data The data buffer to read.
* \param data_length The data buffer length.
* \param iv The IV to use.
* \param iv_length The IV's length.
* \param mic Output buffer to hold the MIC to be generated.
* \param mic_len The size of the MIC to be generated. <= 16.
*/
void (* ctr)(const uint8_t *extended_source_address);
void (* ctr)( uint8_t* data, uint8_t data_length,
const uint8_t* iv, uint8_t iv_len);
/**
* \brief Sets the key in use. Default implementation calls AES_128.set_key()
* \param key The key to use.
*/
void (* set_key)(const uint8_t* key);
};
extern const struct ccm_star_driver CCM_STAR;
#endif /* CCM_STAR_H_ */
/** @} */

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@ -0,0 +1,52 @@
/**
* \file
* CCM* convenience functions for LLSEC use
* \author
* Justin King-Lacroix <justin.kinglacroix@gmail.com>
*/
#include "lib/ccm-star.h"
#include "net/packetbuf.h"
#include <string.h>
/*---------------------------------------------------------------------------*/
void ccm_star_mic_packetbuf(const uint8_t *extended_source_address,
uint8_t *result,
uint8_t mic_len)
{
uint8_t *dataptr = packetbuf_dataptr();
uint8_t data_len = packetbuf_datalen();
uint8_t *headerptr = packetbuf_hdrptr();
uint8_t header_len = packetbuf_hdrlen();
uint8_t iv[13];
memcpy(iv, extended_source_address, 8);
iv[8] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) >> 8;
iv[9] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) & 0xff;
iv[10] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) >> 8;
iv[11] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) & 0xff;
iv[12] = packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL);
if(packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL) & (1 << 2)) {
CCM_STAR.mic(dataptr, data_len, iv, 13, headerptr, header_len, result, mic_len);
} else {
CCM_STAR.mic(dataptr, 0, iv, 13, headerptr, packetbuf_totlen(), result, mic_len);
}
}
/*---------------------------------------------------------------------------*/
void ccm_star_ctr_packetbuf(const uint8_t *extended_source_address)
{
uint8_t *dataptr = packetbuf_dataptr();
uint8_t data_len = packetbuf_datalen();
uint8_t iv[13];
memcpy(iv, extended_source_address, 8);
iv[8] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) >> 8;
iv[9] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) & 0xff;
iv[10] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) >> 8;
iv[11] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) & 0xff;
iv[12] = packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL);
CCM_STAR.ctr(dataptr, data_len, iv, 13);
}
/*---------------------------------------------------------------------------*/

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@ -0,0 +1,24 @@
/**
* \file
* CCM* convenience functions for MAC security
* \author
* Justin King-Lacroix <justin.kinglacroix@gmail.com>
*/
#ifndef CCM_STAR_PACKETBUF_H_
#define CCM_STAR_PACKETBUF_H_
/**
* \brief Calls CCM_STAR.mic with parameters appropriate for LLSEC.
*/
void ccm_star_mic_packetbuf(const uint8_t *extended_source_address,
uint8_t *result,
uint8_t mic_len);
/**
* \brief Calls CCM_STAR.ctr with parameters appropriate for LLSEC.
*/
void ccm_star_ctr_packetbuf(const uint8_t *extended_source_address);
#endif /* CCM_STAR_PACKETBUF_H_ */

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@ -45,13 +45,13 @@
#include "net/llsec/noncoresec/noncoresec.h"
#include "net/llsec/anti-replay.h"
#include "net/llsec/llsec802154.h"
#include "net/llsec/ccm-star.h"
#include "net/llsec/ccm-star-packetbuf.h"
#include "net/mac/frame802154.h"
#include "net/netstack.h"
#include "net/packetbuf.h"
#include "net/nbr-table.h"
#include "net/linkaddr.h"
#include "lib/aes-128.h"
#include "lib/ccm-star.h"
#include <string.h>
#define WITH_ENCRYPTION (LLSEC802154_SECURITY_LEVEL & (1 << 2))
@ -110,15 +110,12 @@ send(mac_callback_t sent, void *ptr)
static int
on_frame_created(void)
{
uint8_t *dataptr;
uint8_t data_len;
uint8_t *dataptr = packetbuf_dataptr();
uint8_t data_len = packetbuf_datalen();
dataptr = packetbuf_dataptr();
data_len = packetbuf_datalen();
CCM_STAR.mic(get_extended_address(&linkaddr_node_addr), dataptr + data_len, LLSEC802154_MIC_LENGTH);
ccm_star_mic_packetbuf(get_extended_address(&linkaddr_node_addr), dataptr + data_len, LLSEC802154_MIC_LENGTH);
#if WITH_ENCRYPTION
CCM_STAR.ctr(get_extended_address(&linkaddr_node_addr));
ccm_star_ctr_packetbuf(get_extended_address(&linkaddr_node_addr));
#endif /* WITH_ENCRYPTION */
packetbuf_set_datalen(data_len + LLSEC802154_MIC_LENGTH);
@ -132,6 +129,8 @@ input(void)
uint8_t *received_mic;
const linkaddr_t *sender;
struct anti_replay_info* info;
uint8_t *dataptr = packetbuf_dataptr();
uint8_t data_len = packetbuf_datalen();
if(packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL) != LLSEC802154_SECURITY_LEVEL) {
PRINTF("noncoresec: received frame with wrong security level\n");
@ -143,14 +142,15 @@ input(void)
return;
}
packetbuf_set_datalen(packetbuf_datalen() - LLSEC802154_MIC_LENGTH);
data_len -= LLSEC802154_MIC_LENGTH;
packetbuf_set_datalen(data_len);
#if WITH_ENCRYPTION
CCM_STAR.ctr(get_extended_address(sender));
ccm_star_ctr_packetbuf(get_extended_address(sender));
#endif /* WITH_ENCRYPTION */
CCM_STAR.mic(get_extended_address(sender), generated_mic, LLSEC802154_MIC_LENGTH);
ccm_star_mic_packetbuf(get_extended_address(sender), generated_mic, LLSEC802154_MIC_LENGTH);
received_mic = ((uint8_t *) packetbuf_dataptr()) + packetbuf_datalen();
received_mic = dataptr + data_len;
if(memcmp(generated_mic, received_mic, LLSEC802154_MIC_LENGTH) != 0) {
PRINTF("noncoresec: received nonauthentic frame %"PRIu32"\n",
anti_replay_get_counter());
@ -203,7 +203,7 @@ get_overhead(void)
static void
bootstrap(llsec_on_bootstrapped_t on_bootstrapped)
{
AES_128.set_key(key);
CCM_STAR.set_key(key);
nbr_table_register(anti_replay_table, NULL);
on_bootstrapped();
}

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@ -41,9 +41,9 @@
#include "net/packetbuf.h"
#include "net/netstack.h"
#include "net/llsec/llsec802154.h"
#include "net/llsec/ccm-star.h"
#include "lib/ccm-star.h"
#include "net/llsec/ccm-star-packetbuf.h"
#include "net/mac/frame802154.h"
#include "lib/aes-128.h"
#include <stdio.h>
#include <string.h>
@ -86,8 +86,8 @@ test_sec_lvl_6()
packetbuf_set_attr(PACKETBUF_ATTR_SECURITY_LEVEL, LLSEC802154_SECURITY_LEVEL);
packetbuf_hdrreduce(29);
AES_128.set_key(key);
CCM_STAR.mic(extended_source_address, mic, LLSEC802154_MIC_LENGTH);
CCM_STAR.set_key(key);
ccm_star_mic_packetbuf(extended_source_address, mic, LLSEC802154_MIC_LENGTH);
if(memcmp(mic, oracle, LLSEC802154_MIC_LENGTH) == 0) {
printf("Success\n");
@ -97,7 +97,7 @@ test_sec_lvl_6()
printf("Testing encryption ... ");
CCM_STAR.ctr(extended_source_address);
ccm_star_ctr_packetbuf(extended_source_address);
if(((uint8_t *) packetbuf_hdrptr())[29] == 0xD8) {
printf("Success\n");
} else {
@ -105,7 +105,7 @@ test_sec_lvl_6()
}
printf("Testing decryption ... ");
CCM_STAR.ctr(extended_source_address);
ccm_star_ctr_packetbuf(extended_source_address);
if(((uint8_t *) packetbuf_hdrptr())[29] == 0xCE) {
printf("Success\n");
} else {

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@ -41,9 +41,10 @@
#include "net/packetbuf.h"
#include "net/netstack.h"
#include "net/llsec/llsec802154.h"
#include "net/llsec/ccm-star.h"
#include "net/llsec/ccm-star-packetbuf.h"
#include "net/mac/frame802154.h"
#include "lib/aes-128.h"
#include "lib/ccm-star.h"
#include <stdio.h>
#include <string.h>
@ -112,8 +113,8 @@ test_sec_lvl_2()
packetbuf_set_attr(PACKETBUF_ATTR_SECURITY_LEVEL, LLSEC802154_SECURITY_LEVEL);
packetbuf_hdrreduce(18);
AES_128.set_key(key);
CCM_STAR.mic(extended_source_address, mic, LLSEC802154_MIC_LENGTH);
CCM_STAR.set_key(key);
ccm_star_mic_packetbuf(extended_source_address,mic, LLSEC802154_MIC_LENGTH);
if(memcmp(mic, oracle, LLSEC802154_MIC_LENGTH) == 0) {
printf("Success\n");