SecurityService.h

00001 #ifndef __BLE_SECURITY_SERVICE_H__
00002 #define __BLE_SECURITY_SERVICE_H__
00003 
00004 #include "Crypto.h"
00005 #include "Random.h"
00006 
00007 class SecurityService {
00008 public:
00009     const static uint16_t SECURITY_SERVICE_UUID              = 0x3000;
00010     const static uint16_t SECURITY_IV_CHARACTERISTIC_UUID = 0x3001;
00011     const static uint16_t SECURITY_KEY_CHARACTERISTIC_UUID = 0x3002;
00012     
00013     SecurityService(BLE &_ble) :
00014         ble(_ble), 
00015         SecurityIV(SECURITY_IV_CHARACTERISTIC_UUID, (uint8_t *) "IV"),
00016         SecurityKey(SECURITY_KEY_CHARACTERISTIC_UUID, (uint8_t *) "KEY")
00017     {
00018         GattCharacteristic *charTable[] = {&SecurityIV, &SecurityKey};
00019         
00020         GattService         SecurityService(SECURITY_SERVICE_UUID, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));
00021         ble.gattServer().addService(SecurityService);
00022     }
00023     void init(char *shared_key) {
00024         //Initialize AES
00025         uint8_t new_iv[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
00026         memcpy(iv, new_iv,16);
00027         ble.gattServer().write(SecurityIV.getValueHandle(), (uint8_t *)iv, 16*sizeof(uint8_t));    
00028         setKey(shared_key);
00029     }
00030 
00031     void decode(uint8_t *out, uint8_t *in, uint32_t len) {
00032         AES myAES(AES_128, myKey, iv);
00033         myAES.decrypt(out,in,len);
00034         genIV();
00035     }
00036     
00037     void setKey(char *shared_key) {
00038         DBG("Set shared_key = %s\r\n", shared_key);
00039         MD5::computeHash(myKey, (uint8_t*) shared_key, strlen(shared_key));
00040     } 
00041 
00042     void genIV() {
00043         Random rnd;
00044         rnd.init();
00045         rnd.getBytes(iv, 16);
00046         ble.gattServer().write(SecurityIV.getValueHandle(), (uint8_t *)iv, 16*sizeof(uint8_t));    
00047     }
00048     
00049     GattAttribute::Handle_t getKeyHandle() const {
00050         return SecurityKey.getValueHandle();
00051     }
00052     
00053 private:
00054     uint8_t iv[16];
00055     uint8_t myKey[16];
00056 
00057     BLE   &ble;
00058     ReadOnlyArrayGattCharacteristic<uint8_t, 16> SecurityIV;
00059     WriteOnlyArrayGattCharacteristic<uint8_t, 16> SecurityKey;    
00060 };
00061 
00062 #endif /* #ifndef __BLE_SECURITY_SERVICE_H__ */