% !TEX root = btstack_gettingstarted.tex
\section{SM API}
\label{appendix:api_sm}
$ $
\begin{lstlisting}
/**
 * @brief Security Manager event
 */
typedef struct sm_event {
    uint8_t   type;                 ///< See <btstack/hci_cmds.h> SM_...
    uint8_t   addr_type;
    bd_addr_t address;
    uint32_t  passkey;              ///< only used for SM_PASSKEY_DISPLAY_NUMBER 
    uint16_t  le_device_db_index;   ///< only used for SM_IDENTITY_RESOLVING_..
    uint8_t   authorization_result; ///< only use for SM_AUTHORIZATION_RESULT
} sm_event_t;

/**
 * @brief Initializes the Security Manager, connects to L2CAP
 */
void sm_init();

/**
 * @brief Set secret ER key for key generation as described in Core V4.0, Vol 3, Part G, 5.2.2 
 * @param er
 */
void sm_set_er(sm_key_t er);

/**
 * @brief Set secret IR key for key generation as described in Core V4.0, Vol 3, Part G, 5.2.2 
 */
void sm_set_ir(sm_key_t ir);

/**
 *
 * @brief Registers OOB Data Callback. The callback should set the oob_data and return 1 if OOB data is availble
 * @param get_oob_data_callback
 */
void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data));

/**
 *
 * @brief Registers packet handler. Called by att_server.c
 */
void sm_register_packet_handler(btstack_packet_handler_t handler);

/**
 * @brief Limit the STK generation methods. Bonding is stopped if the resulting one isn't in the list
 * @param OR combination of SM_STK_GENERATION_METHOD_ 
 */
void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods);

/**
 * @brief Set the accepted encryption key size range. Bonding is stopped if the result isn't within the range
 * @param min_size (default 7)
 * @param max_size (default 16)
 */
void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size);

/**
 * @brief Sets the requested authentication requirements, bonding yes/no, MITM yes/no
 * @param OR combination of SM_AUTHREQ_ flags
 */
void sm_set_authentication_requirements(uint8_t auth_req);

/**
 * @brief Sets the available IO Capabilities
 * @param IO_CAPABILITY_
 */
void sm_set_io_capabilities(io_capability_t io_capability);

/**
 * @brief Let Peripheral request an encrypted connection right after connecting
 * @note Not used normally. Bonding is triggered by access to protected attributes in ATT Server
 */
void sm_set_request_security(int enable);

/** 
 * @brief Trigger Security Request
 * @note Not used normally. Bonding is triggered by access to protected attributes in ATT Server
 */
void sm_send_security_request(uint16_t handle);

/**
 * @brief Decline bonding triggered by event before
 * @param addr_type and address
 */
void sm_bonding_decline(uint8_t addr_type, bd_addr_t address);

/**
 * @brief Confirm Just Works bonding 
 * @param addr_type and address
 */
void sm_just_works_confirm(uint8_t addr_type, bd_addr_t address);

/**
 * @brief Reports passkey input by user
 * @param addr_type and address
 * @param passkey in [0..999999]
 */
void sm_passkey_input(uint8_t addr_type, bd_addr_t address, uint32_t passkey);

/**
 *
 * @brief Get encryption key size.
 * @param addr_type and address
 * @return 0 if not encrypted, 7-16 otherwise
 */
int sm_encryption_key_size(uint8_t addr_type, bd_addr_t address);

/**
 * @brief Get authentication property.
 * @param addr_type and address
 * @return 1 if bonded with OOB/Passkey (AND MITM protection)
 */
int sm_authenticated(uint8_t addr_type, bd_addr_t address);

/**
 * @brief Queries authorization state.
 * @param addr_type and address
 * @return authorization_state for the current session
 */
authorization_state_t sm_authorization_state(uint8_t addr_type, bd_addr_t address);

/**
 * @brief Used by att_server.c to request user authorization.
 * @param addr_type and address
 */
void sm_request_authorization(uint8_t addr_type, bd_addr_t address);

/**
 * @brief Report user authorization decline.
 * @param addr_type and address
 */
void sm_authorization_decline(uint8_t addr_type, bd_addr_t address);

/**
 * @brief Report user authorization grant.
 * @param addr_type and address
 */
void sm_authorization_grant(uint8_t addr_type, bd_addr_t address);

/**
 * @brief Support for signed writes, used by att_server.
 * @note Message and result are in little endian to allows passing in ATT PDU without flipping them first.
 */
int  sm_cmac_ready();
void sm_cmac_start(sm_key_t k, uint16_t message_len, uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t hash[8]));

/**
 * @brief Identify device in LE Device DB.
 * @param handle
 * @return index from le_device_db or -1 if not found/identified
 */
int sm_le_device_index(uint16_t handle );
\end{lstlisting}
\pagebreak