Merge pull request #1108 from phoenix-frozen/generify-ccm-star

generalised CCM module into lib

core/lib/ccm-star.c

@@ -34,44 +34,37 @@
  * \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>
  */
 
-/**
+#include "ccm-star.h"
- * \addtogroup llsec802154
- * @{
- */
-
-#include "net/llsec/ccm-star.h"
-#include "net/llsec/llsec802154.h"
-#include "net/packetbuf.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
+
 /*---------------------------------------------------------------------------*/
 static void
-set_nonce(uint8_t *nonce,
+set_nonce(uint8_t *iv,
     uint8_t flags,
-    const uint8_t *extended_source_address,
+    const uint8_t *nonce,
     uint8_t counter)
 {
   /* 1 byte||          8 bytes        ||    4 bytes    || 1 byte  || 2 bytes */
   /* flags || extended_source_address || frame_counter || sec_lvl || counter */
-  
+
-  nonce[0] = flags;
+  iv[0] = flags;
-  memcpy(nonce + 1, extended_source_address, 8);
+  memcpy(iv + 1, nonce, CCM_STAR_NONCE_LENGTH);
-  nonce[9] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) >> 8;
+  iv[14] = 0;
-  nonce[10] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) & 0xff;
+  iv[15] = counter;
-  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;
-  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 *nonce,
     uint8_t pos,
     uint8_t *m_and_result,
     uint8_t m_len,
@@ -80,7 +73,7 @@ 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, nonce, counter);
   AES_128.encrypt(a);
   
   for(i = 0; (pos + i < m_len) && (i < AES_128_BLOCK_SIZE); i++) {
@@ -89,43 +82,20 @@ 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 *nonce,
+    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);
+  set_nonce(x, CCM_STAR_AUTH_FLAGS(a_len, mic_len), nonce, m_len);
-  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,
-      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 > 0) {
-  if(a_len) {
     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 +113,7 @@ mic(const uint8_t *extended_source_address,
     }
   }
   
-#if LLSEC802154_USES_ENCRYPTION
+  if(m_len > 0) {
-  if(shall_encrypt) {
     m = a + a_len;
     pos = 0;
     while(pos < m_len) {
@@ -155,36 +124,33 @@ 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(nonce, 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* nonce)
 {
-  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(nonce, 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
 };
 /*---------------------------------------------------------------------------*/
-
-/** @} */

core/lib/ccm-star.h

@@ -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
@@ -58,28 +48,43 @@
 #define CCM_STAR ccm_star_driver
 #endif /* CCM_STAR_CONF */
 
+#define CCM_STAR_NONCE_LENGTH 13
+
 /**
  * Structure of CCM* drivers.
  */
 struct ccm_star_driver {
   
    /**
-    * \brief         Generates a MIC over the frame in the packetbuf.
+    * \brief             Generates a MIC over the data supplied.
-    * \param result  The generated MIC will be put here
+    * \param data        The data buffer to read.
-    * \param mic_len  <= 16; set to LLSEC802154_MIC_LENGTH to be compliant
+    * \param data_length The data buffer length.
+    * \param nonce       The nonce to use. CCM_STAR_NONCE_LENGTH bytes long.
+    * \param result      The generated MIC will be put here
+    * \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* nonce,
+      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 nonce       The nonce to use. CCM_STAR_NONCE_LENGTH bytes long.
    */
-  void (* ctr)(const uint8_t *extended_source_address);
+  void (* ctr)(      uint8_t* data, uint8_t data_length,
+               const uint8_t* nonce);
+  
+  /**
+   * \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_ */
-
-/** @} */

core/net/llsec/ccm-star-packetbuf.c

@@ -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 nonce[CCM_STAR_NONCE_LENGTH];
+  
+  memcpy(nonce, extended_source_address, 8);
+  nonce[8] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) >> 8;
+  nonce[9] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) & 0xff;
+  nonce[10] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) >> 8;
+  nonce[11] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) & 0xff;
+  nonce[12] = packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL);
+
+  if(packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL) & (1 << 2)) {
+    CCM_STAR.mic(dataptr, data_len, nonce, headerptr, header_len, result, mic_len);
+  } else {
+    CCM_STAR.mic(dataptr, 0, nonce, 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 nonce[CCM_STAR_NONCE_LENGTH];
+  
+  memcpy(nonce, extended_source_address, 8);
+  nonce[8] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) >> 8;
+  nonce[9] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) & 0xff;
+  nonce[10] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) >> 8;
+  nonce[11] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) & 0xff;
+  nonce[12] = packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL);
+
+  CCM_STAR.ctr(dataptr, data_len, nonce);
+}
+/*---------------------------------------------------------------------------*/

core/net/llsec/ccm-star-packetbuf.h

@@ -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_ */
+

core/net/llsec/noncoresec/noncoresec.c

@@ -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 *dataptr = packetbuf_dataptr();
-  uint8_t data_len;  
+  uint8_t data_len = packetbuf_datalen();
-  
+
-  dataptr = packetbuf_dataptr();
+  ccm_star_mic_packetbuf(get_extended_address(&linkaddr_node_addr), dataptr + data_len, LLSEC802154_MIC_LENGTH);
-  data_len = packetbuf_datalen();
-  
-  CCM_STAR.mic(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();
 }

examples/llsec/ccm-star-tests/encryption/tests.c

@@ -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.set_key(key);
-  CCM_STAR.mic(extended_source_address, mic, LLSEC802154_MIC_LENGTH);
+  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 {

examples/llsec/ccm-star-tests/verification/tests.c

@@ -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.set_key(key);
-  CCM_STAR.mic(extended_source_address, mic, LLSEC802154_MIC_LENGTH);
+  ccm_star_mic_packetbuf(extended_source_address,mic, LLSEC802154_MIC_LENGTH);
   
   if(memcmp(mic, oracle, LLSEC802154_MIC_LENGTH) == 0) {
     printf("Success\n");