1 // ********************************************************************* 2 // Custom DPA Handler code example - User data en/decryption * 3 // ********************************************************************* 4 // Copyright (c) MICRORISC s.r.o. 5 // 6 // File: $RCSfile: CustomDpaHandler-UserEncryption.c,v $ 7 // Version: $Revision: 1.15 $ 8 // Date: $Date: 2021/04/26 15:13:51 $ 9 // 10 // Revision history: 11 // 2017/03/13 Release for DPA 3.00 12 // 13 // ********************************************************************* 14 15 // On-line DPA documentation https://doc.iqrf.org/DpaTechGuide/ 16 17 /* This example shows the usage of the user data en/decryption using AES-128 18 19 User peripheral PNUM=0x20 and 2 commands are implemented: 20 * PCMD=0 returns first 16 bytes of peripheral RAM encrypted by User key 21 * PCMD=1 writes 16 bytes of data encrypted by the User key to the peripheral RAM 22 23 The initial content of the peripheral RAM after the device is restarted is 0,1,2,3,4,5,6,7,8,"AES-128". 24 25 You can use a public on-line AES tools to en/decrypt to play with the commands. 26 27 [Example 1] 28 * Restart module 29 * Run PCMD=0. It returns the initial text from peripheral RAM encrypted by the User key (initial value is 00000000000000000000000000000000). Returned data is ce61d785c84e30883973340aea2e6dcf 30 * Go to http://testprotect.com/appendix/AEScalc 31 * Enter 00000000000000000000000000000000 to "AES key (in hex):" 32 * Enter ce61d785c84e30883973340aea2e6dcf to "Input Data (in hex):" 33 * Press "Decrypt it", the result is 0001020304050607084145532d313238, which corresponds to the expected 0,1,2,3,4,5,6,7,8,"AES-128" 34 35 [Example 2] 36 * Go to http://testprotect.com/appendix/AEScalc 37 * Enter 00000000000000000000000000000000 to "AES key (in hex):" 38 * Enter aaBBccDDeeFFaaBBccDDeeFFaaBBccDD to "Input Data (in hex):" 39 * Press "Encrypt it", the result is e37967714d9be9e66bc03629427de452 40 * Run PCMD=1 with data "e37967714d9be9e66bc03629427de452" 41 * Read 16 bytes from address 0 of peripheral Ram. The result is expected aaBBccDDeeFFaaBBccDDeeFFaaBBccDD 42 43 Note: another AES tool that works well is http://aes.online-domain-tools.com/ 44 45 */ 46 47 // Default IQRF include (modify the path according to your setup) 48 #include "IQRF.h" 49 50 // Default DPA header (modify the path according to your setup) 51 #include "DPA.h" 52 // Default Custom DPA Handler header (modify the path according to your setup) 53 #include "DPAcustomHandler.h" 54 55 //############################################################################################ 56 57 // Must be the 1st defined function in the source code in order to be placed at the correct FLASH location! 58 //############################################################################################ 59 bit CustomDpaHandler() 60 //############################################################################################ 61 { 62 // Handler presence mark 63 clrwdt(); 64 65 // Detect DPA event to handle 66 switch ( GetDpaEvent() ) 67 { 68 // ------------------------------------------------- 69 case DpaEvent_Interrupt: 70 // Do an extra quick background interrupt work 71 // ! The time spent handling this event is critical.If there is no interrupt to handle return immediately otherwise keep the code as fast as possible. 72 // ! Make sure the event is the 1st case in the main switch statement at the handler routine.This ensures that the event is handled as the 1st one. 73 // ! It is desirable that this event is handled with immediate return even if it is not used by the custom handler because the Interrupt event is raised on every MCU interrupt and the “empty” return handler ensures the shortest possible interrupt routine response time. 74 // ! Only global variables or local ones marked by static keyword can be used to allow reentrancy. 75 // ! Make sure race condition does not occur when accessing those variables at other places. 76 // ! Make sure( inspect.lst file generated by C compiler ) compiler does not create any hidden temporary local variable( occurs when using division, multiplication or bit shifts ) at the event handler code.The name of such variable is usually Cnumbercnt. 77 // ! Do not call any OS functions except setINDFx(). 78 // ! Do not use any OS variables especially for writing access. 79 // ! All above rules apply also to any other function being called from the event handler code, although calling any function from Interrupt event is not recommended because of additional MCU stack usage. 80 81 return Carry; 82 83 // ------------------------------------------------- 84 case DpaEvent_Init: 85 // Do a one time initialization before main loop starts 86 87 // Initialize en/decrypted user data 88 PeripheralRam[0x0] = 0; 89 PeripheralRam[0x1] = 1; 90 PeripheralRam[0x2] = 2; 91 PeripheralRam[0x3] = 3; 92 PeripheralRam[0x4] = 4; 93 PeripheralRam[0x5] = 5; 94 PeripheralRam[0x6] = 6; 95 PeripheralRam[0x7] = 7; 96 PeripheralRam[0x8] = 8; 97 PeripheralRam[0x9] = 'A'; 98 PeripheralRam[0xA] = 'E'; 99 PeripheralRam[0xB] = 'S'; 100 PeripheralRam[0xC] = '-'; 101 PeripheralRam[0xD] = '1'; 102 PeripheralRam[0xE] = '2'; 103 PeripheralRam[0xF] = '8'; 104 break; 105 106 // ------------------------------------------------- 107 case DpaEvent_DpaRequest: 108 // Called to interpret DPA request for peripherals 109 // ------------------------------------------------- 110 // Peripheral enumeration 111 if ( IsDpaEnumPeripheralsRequest() ) 112 { 113 // We implement 1 user peripheral 114 _DpaMessage.EnumPeripheralsAnswer.UserPerNr = 1; 115 FlagUserPer( _DpaMessage.EnumPeripheralsAnswer.UserPer, PNUM_USER + 0 ); 116 _DpaMessage.EnumPeripheralsAnswer.HWPID = 0x000F; 117 _DpaMessage.EnumPeripheralsAnswer.HWPIDver = 0x1234; 118 119 DpaHandleReturnTRUE: 120 return TRUE; 121 } 122 // ------------------------------------------------- 123 // Get information about peripheral 124 else if ( IsDpaPeripheralInfoRequest() ) 125 { 126 if ( _PNUM == PNUM_USER + 0 ) 127 { 128 _DpaMessage.PeripheralInfoAnswer.PerT = PERIPHERAL_TYPE_USER_AREA; 129 _DpaMessage.PeripheralInfoAnswer.PerTE = PERIPHERAL_TYPE_EXTENDED_READ_WRITE; 130 goto DpaHandleReturnTRUE; 131 } 132 133 break; 134 } 135 // ------------------------------------------------- 136 else 137 { 138 // Handle peripheral command 139 if ( _PNUM == PNUM_USER + 0 ) 140 { 141 switch ( _PCMD ) 142 { 143 // Read data 144 case 0x00: 145 { 146 // No input data 147 if ( _DpaDataLength != 0 ) 148 DpaApiReturnPeripheralError( ERROR_DATA_LEN ); 149 150 // Copy data to the result, the result length is 16 bytes (one AES block) 151 copyMemoryBlock( PeripheralRam, _DpaMessage.Response.PData, _DpaDataLength = 16 ); 152 // Encrypt data (_DpaMessage.Response.PData is actually bufferRF) 153 encryptBufferRF( 1 ); 154 return TRUE; 155 } 156 157 // Write data 158 case 0x01: 159 { 160 // Exactly one AES block of input data is expected 161 if ( _DpaDataLength != 16 ) 162 DpaApiReturnPeripheralError( ERROR_DATA_LEN ); 163 164 // Decrypt data to write (_DpaMessage.Response.PData is actually bufferRF) 165 decryptBufferRF( 1 ); 166 // Copy written data to the buffer 167 copyMemoryBlock( _DpaMessage.Request.PData, PeripheralRam, 16 ); 168 // No data is written 169 _DpaDataLength = 0; 170 return TRUE; 171 } 172 173 // Invalid command 174 default: 175 DpaApiReturnPeripheralError( ERROR_PCMD ); 176 } 177 } 178 } 179 } 180 181 return FALSE; 182 } 183 184 //############################################################################################ 185 // Default Custom DPA Handler header; 2nd include to implement Code bumper to detect too long code of the Custom DPA Handler (modify the path according to your setup) 186 #include "DPAcustomHandler.h" 187 //############################################################################################