Routines to initiate key establishment, handle key establishment callbacks, and print info about the security keys on the device.

License#

Copyright 2018 Silicon Laboratories Inc. www.silabs.com

The licensor of this software is Silicon Laboratories Inc. Your use of this software is governed by the terms of Silicon Labs Master Software License Agreement (MSLA) available at www.silabs.com/about-us/legal/master-software-license-agreement. This software is distributed to you in Source Code format and is governed by the sections of the MSLA applicable to Source Code.

/***************************************************************************/
#include "app/framework/util/common.h"

#include "app/framework/util/service-discovery.h"

#include "app/util/serial/command-interpreter2.h"
#include "app/framework/cli/security-cli.h"
#include "app/framework/util/af-main.h"

#include "app/framework/security/af-security.h"

#ifdef EZSP_HOST
 #define setTcRejoinsUsingWellKnownKeyAllowed(allow) \
  (void)ezspSetPolicy(EZSP_TC_REJOINS_USING_WELL_KNOWN_KEY_POLICY, (allow))
 #define setTcRejoinsUsingWellKnownKeyTimeout(timeout) \
  (void)ezspSetConfigurationValue(EZSP_CONFIG_TC_REJOINS_USING_WELL_KNOWN_KEY_TIMEOUT_S, (timeout))
 #define getTransientKeyTableEntry ezspGetTransientKeyTableEntry
#else  // SoC
extern uint16_t emAllowTcRejoinsUsingWellKnownKeyTimeoutSec;
 #define setTcRejoinsUsingWellKnownKeyAllowed(allow) \
  emberSetTcRejoinsUsingWellKnownKeyAllowed((allow))
 #define setTcRejoinsUsingWellKnownKeyTimeout(timeout) \
  emAllowTcRejoinsUsingWellKnownKeyTimeoutSec = (timeout)
 #define getTransientKeyTableEntry emberGetTransientKeyTableEntry
#endif

//------------------------------------------------------------------------------
// Globals

EmberKeyData cliPreconfiguredLinkKey = DUMMY_KEY;
EmberKeyData cliNetworkKey           = DUMMY_KEY;

#define EMBER_AF_DOXYGEN_CLI__SECURITY_CHANGEKEY_COMMANDS

#define EMBER_AF_DOXYGEN_CLI__SECURITY_CBKE_COMMANDS

#ifndef EMBER_AF_GENERATE_CLI

EmberCommandEntry changeKeyCommands[] = {
  { "link", changeKeyCommand, "b" },
  { "network", changeKeyCommand, "b" },
  { NULL }
};

#endif // EMBER_AF_GENERATE_CLI

#define EMBER_AF_DOXYGEN_CLI__SECURITY_MFG_TOKEN_COMMANDS

#ifndef EMBER_AF_HAS_SECURITY_PROFILE_NONE
void getSetMfgToken(void);

EmberCommandEntry mfgToken[] = {
  emberCommandEntryAction("get", getSetMfgToken, "",
                          "Print the MFG security config token"),
  emberCommandEntryAction("set", getSetMfgToken, "wv",
                          "Set the MFG Security config token.  CANNOT BE UNSET BY CLI."),
  emberCommandEntryTerminator(),
};

EmberCommandEntry emAfSecurityCommands[] = {
  emberCommandEntrySubMenu("mfg-token", mfgToken,
                           "Get/set the MFG Security config token"),
  emberCommandEntryTerminator(),
};

#endif

//------------------------------------------------------------------------------
// Forward Declarations

uint8_t printKeyTable(bool preconfiguredKey);
uint8_t printTransientKeyTable(void);
uint32_t getOutgoingApsFrameCounter(void);

//------------------------------------------------------------------------------

// ******************************************************
// changekey link    <16 byte key>
// changekey network <16 byte key>
// ******************************************************

// Changes the default link or network key that will be used when
// forming or joining a network.
void changeKeyCommand(void)
{
  if (EMBER_NO_NETWORK != emberNetworkState()) {
    emberAfCorePrintln("%pstack must be down.", "ERROR: ");
  } else {
    emberCopyKeyArgument(0,
                         emberCurrentCommand->name[0] == 'l'
                         ? &cliPreconfiguredLinkKey
                         : &cliNetworkKey);
    emberAfDebugPrintln("set key");
  }
}

// Key Establishment commands (cbke <command>) moved to
//   app/framework/plugin/key-establishment/key-establishment-cli.c

void printKeyInfo(void)
{
  uint8_t entriesUsed;
  EmberKeyStruct nwkKey;

#ifndef EMBER_AF_HAS_SECURITY_PROFILE_NONE
  {
    EmberMfgSecurityStruct config;
    if (EMBER_SUCCESS == emberGetMfgSecurityConfig(&config)) {
      if (!(config.keySettings & EMBER_KEY_PERMISSIONS_READING_ALLOWED)) {
        emberAfCorePrintln("\nWARNING:  READING OF KEY VALUES DISABLED BY MFG TOKEN\n");
        emberAfCoreFlush();
      }
    }
  }
#endif

  if ( EMBER_SUCCESS != emberGetKey(EMBER_CURRENT_NETWORK_KEY,
                                    &nwkKey)) {
    MEMSET((uint8_t*)&nwkKey, 0xFF, sizeof(EmberKeyStruct));
  }
  emberAfCorePrintln("%p out FC: %4x",
                     "NWK Key",
                     nwkKey.outgoingFrameCounter);
  emberAfCorePrintln("%p seq num: 0x%x",
                     "NWK Key",
                     nwkKey.sequenceNumber);
  emberAfCorePrint("%p: ",
                   "NWK Key");
  emberAfPrintZigbeeKey(emberKeyContents(&nwkKey.key));

  emberAfCorePrintln("%p out FC: %4x",
                     "Link Key",
                     getOutgoingApsFrameCounter());

  emberAfCorePrintln("TC %p", "Link Key");
  emberAfCoreFlush();
  printKeyTable(true);

  emberAfCorePrintln("%p Table", "Link Key");
  emberAfCoreFlush();
  entriesUsed = printKeyTable(false);
  UNUSED_VAR(entriesUsed);

  emberAfCorePrintln("%d/%d entries used.",
                     entriesUsed,
                     emberAfGetKeyTableSize());
  emberAfCoreFlush();

  emberAfCorePrintln("%p Table", "Transient Key");
  emberAfCoreFlush();

  entriesUsed = printTransientKeyTable();
  UNUSED_VAR(entriesUsed);

  emberAfCorePrintln("%d entr%s consuming %d packet buffer%s.",
                     entriesUsed,
                     entriesUsed > 1 ? "ies" : "y",
                     entriesUsed,
                     entriesUsed > 1 ? "s" : "");
  emberAfCoreFlush();
}

uint8_t printKeyTable(bool preconfiguredKey)
{
  uint8_t i;
  uint8_t entriesUsed = 0;
  uint8_t loopCount = (preconfiguredKey ? 1 : emberAfGetKeyTableSize());

  emberAfCorePrintln("Index IEEE Address         In FC     Type  Auth  Key");

  for (i = 0; i < loopCount; i++) {
    EmberKeyStruct entry;

    if (preconfiguredKey) {
      i = 0xFE; // last

      // Try to get whatever key type is stored in the pre-configured key slot.
      if (EMBER_SUCCESS
          != emberGetKey(EMBER_TRUST_CENTER_LINK_KEY, &entry) ) {
        continue;
      }
    } else if ( EMBER_SUCCESS != emberGetKeyTableEntry(i, &entry) ) {
      continue;
    } else {
      // MISRA requires ..else if.. to have a terminating else.
    }

    if (!preconfiguredKey) {
      emberAfCorePrint("%d     ", i);
    } else {
      emberAfCorePrint("-     ");
    }
    emberAfCoreDebugExec(emberAfPrintBigEndianEui64(entry.partnerEUI64));
    emberAfCorePrint("  %4x  ", entry.incomingFrameCounter);
    emberAfCorePrint("L     %c     ",
                     (entry.bitmask & EMBER_KEY_IS_AUTHORIZED
                      ? 'y'
                      : 'n'));

    emberAfPrintZigbeeKey(emberKeyContents(&(entry.key)));

    emberAfCoreFlush();
    entriesUsed++;
  }

  return entriesUsed;
}

uint8_t printTransientKeyTable(void)
{
  EmberStatus status;
  EmberTransientKeyData transientKeyData;
  uint8_t index = 0;

  emberAfCorePrintln("Index IEEE Address         NWKIndex  In FC     TTL(s) Flag    Key    ");

  status = getTransientKeyTableEntry(index, &transientKeyData);

  while (status == EMBER_SUCCESS) {
    emberAfCorePrint("%d     ", index);
    emberAfCoreDebugExec(emberAfPrintBigEndianEui64(transientKeyData.eui64));
    emberAfCorePrint("  %d       ", transientKeyData.networkIndex);
    emberAfCorePrint("  %4x  ", transientKeyData.incomingFrameCounter);
    emberAfCorePrint("0x%02X", transientKeyData.remainingTimeSeconds);
    emberAfCorePrint(" 0x%02X  ", transientKeyData.bitmask);
    emberAfPrintZigbeeKey(emberKeyContents(&(transientKeyData.keyData)));
    emberAfCorePrintln("");
    emberAfCoreFlush();

    index += 1;
    status = getTransientKeyTableEntry(index, &transientKeyData);
  }

  return index;
}

uint32_t getOutgoingApsFrameCounter(void)
{
  EmberKeyStruct entry;
  if (emberGetKey(EMBER_TRUST_CENTER_LINK_KEY, &entry) != EMBER_SUCCESS) {
    return 0xFFFFFFFFUL;
  }
  return entry.outgoingFrameCounter;
}

#ifndef EMBER_AF_HAS_SECURITY_PROFILE_NONE
void getSetMfgToken(void)
{
  EmberMfgSecurityStruct config;
  EmberStatus status;

  if (emberCurrentCommand->name[0] == 'g') {
    status = emberGetMfgSecurityConfig(&config);
    if (status == EMBER_SUCCESS) {
      emberAfSecurityPrintln("EmberKeySettings: 0x%2X", config.keySettings);
      emberAfSecurityPrintln("  Permissions: %p",
                             ((config.keySettings & EMBER_KEY_PERMISSIONS_READING_ALLOWED)
                              ? "Reading Allowed"
                              : ((config.keySettings & EMBER_KEY_PERMISSIONS_HASHING_ALLOWED)
                                 ? "Hashing only"
                                 : "NONE")));
    } else {
      emberAfSecurityPrintln("Error: Failed to get config, status: 0x%X", status);
    }
  } else {
    uint32_t magicNumber = emberUnsignedCommandArgument(0);
    config.keySettings = (EmberKeySettings)emberUnsignedCommandArgument(1);
    status = emberSetMfgSecurityConfig(magicNumber, &config);
  }

  if (status != EMBER_SUCCESS) {
    emberAfSecurityPrintln("Failed: 0x%X", status);
  }
}
#endif

void optionSecurityAllowTrustCenterRejoinUsingWellKnownKey(void)
{
  bool allow = (bool)emberUnsignedCommandArgument(0);
  setTcRejoinsUsingWellKnownKeyAllowed(allow);
  emberAfCorePrintln("Trust Center %p allow trust center rejoins using "
                     "well-known key.",
                     allow
                     ? "WILL"
                     : "WILL NOT");
}

void optionSecurityAllowTrustCenterRejoinUsingWellKnownKeyTimeout(void)
{
  uint16_t timeout = (uint16_t)emberUnsignedCommandArgument(0);
  setTcRejoinsUsingWellKnownKeyTimeout(timeout);
  emberAfCorePrintln("Set timeout for Trust Center rejoins using well-known "
                     "link key to %d seconds.",
                     timeout);
}

void optionSecuritySetKeyRequestPolicy(void)
{
#ifdef EZSP_HOST
  uint8_t tcPolicy = (uint8_t)emberUnsignedCommandArgument(0);
  uint8_t appPolicy = (uint8_t)emberUnsignedCommandArgument(1);

  // The EZSP policies are offset by EZSP_DENY_TC_KEY_REQUESTS and
  // EZSP_DENY_APP_KEY_REQUESTS, respectively
  tcPolicy += EZSP_DENY_TC_KEY_REQUESTS;
  appPolicy += EZSP_DENY_APP_KEY_REQUESTS;

  (void)ezspSetPolicy(EZSP_TC_KEY_REQUEST_POLICY, tcPolicy);
  (void)ezspSetPolicy(EZSP_APP_KEY_REQUEST_POLICY, tcPolicy);
#else // EZSP_HOST
  emberTrustCenterLinkKeyRequestPolicy = (uint8_t)emberUnsignedCommandArgument(0);
  emberAppLinkKeyRequestPolicy = (uint8_t)emberUnsignedCommandArgument(1);
#endif // EZSP_HOST
}