SecurityManager.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2015 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef __SECURITY_MANAGER_H__
00018 #define __SECURITY_MANAGER_H__
00019 
00020 #include <stdint.h>
00021 
00022 #include "Gap.h"
00023 
00024 class SecurityManager {
00025 public:
00026     enum SecurityMode_t {
00027         SECURITY_MODE_NO_ACCESS,
00028         SECURITY_MODE_ENCRYPTION_OPEN_LINK, /**< Require no protection, open link. */
00029         SECURITY_MODE_ENCRYPTION_NO_MITM,   /**< Require encryption, but no MITM protection. */
00030         SECURITY_MODE_ENCRYPTION_WITH_MITM, /**< Require encryption and MITM protection. */
00031         SECURITY_MODE_SIGNED_NO_MITM,       /**< Require signing or encryption, but no MITM protection. */
00032         SECURITY_MODE_SIGNED_WITH_MITM,     /**< Require signing or encryption, and MITM protection. */
00033     };
00034 
00035     /**
00036      * @brief Defines possible security status or states.
00037      *
00038      * @details Defines possible security status or states of a link when requested by getLinkSecurity().
00039      */
00040     enum LinkSecurityStatus_t {
00041         NOT_ENCRYPTED,          /**< The link is not secured. */
00042         ENCRYPTION_IN_PROGRESS, /**< Link security is being established.*/
00043         ENCRYPTED               /**< The link is secure.*/
00044     };
00045 
00046     enum SecurityIOCapabilities_t {
00047       IO_CAPS_DISPLAY_ONLY     = 0x00,   /**< Display only. */
00048       IO_CAPS_DISPLAY_YESNO    = 0x01,   /**< Display and yes/no entry. */
00049       IO_CAPS_KEYBOARD_ONLY    = 0x02,   /**< Keyboard only. */
00050       IO_CAPS_NONE             = 0x03,   /**< No I/O capabilities. */
00051       IO_CAPS_KEYBOARD_DISPLAY = 0x04,   /**< Keyboard and display. */
00052     };
00053 
00054     enum SecurityCompletionStatus_t {
00055         SEC_STATUS_SUCCESS              = 0x00,  /**< Procedure completed with success. */
00056         SEC_STATUS_TIMEOUT              = 0x01,  /**< Procedure timed out. */
00057         SEC_STATUS_PDU_INVALID          = 0x02,  /**< Invalid PDU received. */
00058         SEC_STATUS_PASSKEY_ENTRY_FAILED = 0x81,  /**< Passkey entry failed (user canceled or other). */
00059         SEC_STATUS_OOB_NOT_AVAILABLE    = 0x82,  /**< Out of Band Key not available. */
00060         SEC_STATUS_AUTH_REQ             = 0x83,  /**< Authentication requirements not met. */
00061         SEC_STATUS_CONFIRM_VALUE        = 0x84,  /**< Confirm value failed. */
00062         SEC_STATUS_PAIRING_NOT_SUPP     = 0x85,  /**< Pairing not supported.  */
00063         SEC_STATUS_ENC_KEY_SIZE         = 0x86,  /**< Encryption key size. */
00064         SEC_STATUS_SMP_CMD_UNSUPPORTED  = 0x87,  /**< Unsupported SMP command. */
00065         SEC_STATUS_UNSPECIFIED          = 0x88,  /**< Unspecified reason. */
00066         SEC_STATUS_REPEATED_ATTEMPTS    = 0x89,  /**< Too little time elapsed since last attempt. */
00067         SEC_STATUS_INVALID_PARAMS       = 0x8A,  /**< Invalid parameters. */
00068     };
00069 
00070     /**
00071      * Declaration of type containing a passkey to be used during pairing. This
00072      * is passed into initializeSecurity() to specify a pre-programmed passkey
00073      * for authentication instead of generating a random one.
00074      */
00075     static const unsigned PASSKEY_LEN = 6;
00076     typedef uint8_t Passkey_t[PASSKEY_LEN];         /**< 6-digit passkey in ASCII ('0'-'9' digits only). */
00077 
00078 public:
00079     typedef void (*HandleSpecificEvent_t)(Gap::Handle_t handle);
00080     typedef void (*SecuritySetupInitiatedCallback_t)(Gap::Handle_t, bool allowBonding, bool requireMITM, SecurityIOCapabilities_t iocaps);
00081     typedef void (*SecuritySetupCompletedCallback_t)(Gap::Handle_t, SecurityCompletionStatus_t status);
00082     typedef void (*LinkSecuredCallback_t)(Gap::Handle_t handle, SecurityMode_t securityMode);
00083     typedef void (*PasskeyDisplayCallback_t)(Gap::Handle_t handle, const Passkey_t passkey);
00084 
00085     /*
00086      * The following functions are meant to be overridden in the platform-specific sub-class.
00087      */
00088 public:
00089     /**
00090      * Enable the BLE stack's Security Manager. The Security Manager implements
00091      * the actual cryptographic algorithms and protocol exchanges that allow two
00092      * devices to securely exchange data and privately detect each other.
00093      * Calling this API is a prerequisite for encryption and pairing (bonding).
00094      *
00095      * @param[in]  enableBonding Allow for bonding.
00096      * @param[in]  requireMITM   Require protection for man-in-the-middle attacks.
00097      * @param[in]  iocaps        To specify the I/O capabilities of this peripheral,
00098      *                           such as availability of a display or keyboard, to
00099      *                           support out-of-band exchanges of security data.
00100      * @param[in]  passkey       To specify a static passkey.
00101      *
00102      * @return BLE_ERROR_NONE on success.
00103      */
00104     virtual ble_error_t init(bool                     enableBonding = true,
00105                              bool                     requireMITM   = true,
00106                              SecurityIOCapabilities_t iocaps        = IO_CAPS_NONE,
00107                              const Passkey_t          passkey       = NULL) {
00108         /* Avoid compiler warnings about unused variables. */
00109         (void)enableBonding;
00110         (void)requireMITM;
00111         (void)iocaps;
00112         (void)passkey;
00113 
00114         return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if security is supported. */
00115     }
00116 
00117     /**
00118      * Get the security status of a connection.
00119      *
00120      * @param[in]  connectionHandle   Handle to identify the connection.
00121      * @param[out] securityStatusP    Security status.
00122      *
00123      * @return BLE_SUCCESS or appropriate error code indicating the failure reason.
00124      */
00125     virtual ble_error_t getLinkSecurity(Gap::Handle_t connectionHandle, LinkSecurityStatus_t *securityStatusP) {
00126         /* Avoid compiler warnings about unused variables. */
00127         (void)connectionHandle;
00128         (void)securityStatusP;
00129 
00130         return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if security is supported. */
00131     }
00132 
00133     /**
00134      * Delete all peer device context and all related bonding information from
00135      * the database within the security manager.
00136      *
00137      * @retval BLE_ERROR_NONE             On success, else an error code indicating reason for failure.
00138      * @retval BLE_ERROR_INVALID_STATE    If the API is called without module initialization or
00139      *                                    application registration.
00140      */
00141     virtual ble_error_t purgeAllBondingState(void) {
00142         return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if security is supported. */
00143     }
00144 
00145     /* Event callback handlers. */
00146 public:
00147     /**
00148      * To indicate that a security procedure for the link has started.
00149      */
00150     virtual void onSecuritySetupInitiated(SecuritySetupInitiatedCallback_t callback) {securitySetupInitiatedCallback = callback;}
00151 
00152     /**
00153      * To indicate that the security procedure for the link has completed.
00154      */
00155     virtual void onSecuritySetupCompleted(SecuritySetupCompletedCallback_t callback) {securitySetupCompletedCallback = callback;}
00156 
00157     /**
00158      * To indicate that the link with the peer is secured. For bonded devices,
00159      * subsequent reconnections with a bonded peer will result only in this callback
00160      * when the link is secured; setup procedures will not occur (unless the
00161      * bonding information is either lost or deleted on either or both sides).
00162      */
00163     virtual void onLinkSecured(LinkSecuredCallback_t callback) {linkSecuredCallback = callback;}
00164 
00165     /**
00166      * To indicate that device context is stored persistently.
00167      */
00168     virtual void onSecurityContextStored(HandleSpecificEvent_t callback) {securityContextStoredCallback = callback;}
00169 
00170     /**
00171      * To set the callback for when the passkey needs to be displayed on a peripheral with DISPLAY capability.
00172      */
00173     virtual void onPasskeyDisplay(PasskeyDisplayCallback_t callback) {passkeyDisplayCallback = callback;}
00174 
00175     /* Entry points for the underlying stack to report events back to the user. */
00176 public:
00177     void processSecuritySetupInitiatedEvent(Gap::Handle_t handle, bool allowBonding, bool requireMITM, SecurityIOCapabilities_t iocaps) {
00178         if (securitySetupInitiatedCallback) {
00179             securitySetupInitiatedCallback(handle, allowBonding, requireMITM, iocaps);
00180         }
00181     }
00182 
00183     void processSecuritySetupCompletedEvent(Gap::Handle_t handle, SecurityCompletionStatus_t status) {
00184         if (securitySetupCompletedCallback) {
00185             securitySetupCompletedCallback(handle, status);
00186         }
00187     }
00188 
00189     void processLinkSecuredEvent(Gap::Handle_t handle, SecurityMode_t securityMode) {
00190         if (linkSecuredCallback) {
00191             linkSecuredCallback(handle, securityMode);
00192         }
00193     }
00194 
00195     void processSecurityContextStoredEvent(Gap::Handle_t handle) {
00196         if (securityContextStoredCallback) {
00197             securityContextStoredCallback(handle);
00198         }
00199     }
00200 
00201     void processPasskeyDisplayEvent(Gap::Handle_t handle, const Passkey_t passkey) {
00202         if (passkeyDisplayCallback) {
00203             passkeyDisplayCallback(handle, passkey);
00204         }
00205     }
00206 
00207 protected:
00208     SecurityManager() :
00209         securitySetupInitiatedCallback(),
00210         securitySetupCompletedCallback(),
00211         linkSecuredCallback(),
00212         securityContextStoredCallback(),
00213         passkeyDisplayCallback() {
00214         /* empty */
00215     }
00216 
00217 protected:
00218     SecuritySetupInitiatedCallback_t securitySetupInitiatedCallback;
00219     SecuritySetupCompletedCallback_t securitySetupCompletedCallback;
00220     LinkSecuredCallback_t            linkSecuredCallback;
00221     HandleSpecificEvent_t            securityContextStoredCallback;
00222     PasskeyDisplayCallback_t         passkeyDisplayCallback;
00223 };
00224 
00225 #endif /*__SECURITY_MANAGER_H__*/