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: 1.22 $ 8 // Date: $Date: 2022/02/25 09:41:25 $ 9 // 10 // Revision history: 11 // 2022/02/24 Release for DPA 4.17 12 // 2017/03/13 Release for DPA 3.00 13 // 14 // ********************************************************************* 15 16 // On-line DPA documentation https://doc.iqrf.org/DpaTechGuide/ 17 18 /* This example shows the usage of the user data en/decryption using AES-128 19 20 User peripheral PNUM=0x20 and 2 commands are implemented: 21 * PCMD=0 returns first 16 bytes of peripheral RAM encrypted by User key 22 * PCMD=1 writes 16 bytes of data encrypted by the User key to the peripheral RAM 23 24 The initial content of the peripheral RAM after the device is restarted is 0,1,2,3,4,5,6,7,8,"AES-128". 25 26 You can use a public on-line AES tools to en/decrypt to play with the commands. 27 28 [Example 1] 29 * Restart module 30 * Run PCMD=0. It returns the initial text from peripheral RAM encrypted by the User key (initial value is 00000000000000000000000000000000). Returned data is ce61d785c84e30883973340aea2e6dcf 31 * Go to http://testprotect.com/appendix/AEScalc 32 * Enter 00000000000000000000000000000000 to "AES key (in hex):" 33 * Enter ce61d785c84e30883973340aea2e6dcf to "Input Data (in hex):" 34 * Press "Decrypt it", the result is 0001020304050607084145532d313238, which corresponds to the expected 0,1,2,3,4,5,6,7,8,"AES-128" 35 36 [Example 2] 37 * Go to http://testprotect.com/appendix/AEScalc 38 * Enter 00000000000000000000000000000000 to "AES key (in hex):" 39 * Enter aaBBccDDeeFFaaBBccDDeeFFaaBBccDD to "Input Data (in hex):" 40 * Press "Encrypt it", the result is e37967714d9be9e66bc03629427de452 41 * Run PCMD=1 with data "e37967714d9be9e66bc03629427de452" 42 * Read 16 bytes from address 0 of peripheral Ram. The result is expected aaBBccDDeeFFaaBBccDDeeFFaaBBccDD 43 44 Note: another AES tool that works well is http://aes.online-domain-tools.com/ 45 46 */ 47 48 // Default IQRF include (modify the path according to your setup) 49 #include "IQRF.h" 50 51 // Default DPA header (modify the path according to your setup) 52 #include "DPA.h" 53 // Default Custom DPA Handler header (modify the path according to your setup) 54 #include "DPAcustomHandler.h" 55 56 //############################################################################################ 57 58 // Must be the 1st defined function in the source code in order to be placed at the correct FLASH location! 59 //############################################################################################ 60 bit CustomDpaHandler() 61 //############################################################################################ 62 { 63 // Handler presence mark 64 clrwdt(); 65 66 // Detect DPA event to handle 67 switch ( GetDpaEvent() ) 68 { 69 // ------------------------------------------------- 70 case DpaEvent_Interrupt: 71 // Do an extra quick background interrupt work 72 // ! 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. 73 // ! 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. 74 // ! 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. 75 // ! Only global variables or local ones marked by static keyword can be used to allow reentrancy. 76 // ! Make sure race condition does not occur when accessing those variables at other places. 77 // ! 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. 78 // ! Do not call any OS functions except setINDFx(). 79 // ! Do not use any OS variables especially for writing access. 80 // ! 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. 81 82 return Carry; 83 84 // ------------------------------------------------- 85 case DpaEvent_Init: 86 // Do a one time initialization before main loop starts 87 88 // Initialize en/decrypted user data 89 PeripheralRam[0x0] = 0; 90 PeripheralRam[0x1] = 1; 91 PeripheralRam[0x2] = 2; 92 PeripheralRam[0x3] = 3; 93 PeripheralRam[0x4] = 4; 94 PeripheralRam[0x5] = 5; 95 PeripheralRam[0x6] = 6; 96 PeripheralRam[0x7] = 7; 97 PeripheralRam[0x8] = 8; 98 PeripheralRam[0x9] = 'A'; 99 PeripheralRam[0xA] = 'E'; 100 PeripheralRam[0xB] = 'S'; 101 PeripheralRam[0xC] = '-'; 102 PeripheralRam[0xD] = '1'; 103 PeripheralRam[0xE] = '2'; 104 PeripheralRam[0xF] = '8'; 105 break; 106 107 // ------------------------------------------------- 108 case DpaEvent_DpaRequest: 109 // Called to interpret DPA request for peripherals 110 // ------------------------------------------------- 111 // Peripheral enumeration 112 if ( IsDpaEnumPeripheralsRequest() ) 113 { 114 // We implement 1 user peripheral 115 _DpaMessage.EnumPeripheralsAnswer.UserPerNr |= 1; 116 FlagUserPer( _DpaMessage.EnumPeripheralsAnswer.UserPer, PNUM_USER + 0 ); 117 _DpaMessage.EnumPeripheralsAnswer.HWPID |= 0x000F; 118 _DpaMessage.EnumPeripheralsAnswer.HWPIDver |= 0x1234; 119 120 DpaHandleReturnTRUE: 121 return TRUE; 122 } 123 // ------------------------------------------------- 124 // Get information about peripheral 125 else if ( IsDpaPeripheralInfoRequest() ) 126 { 127 if ( _PNUM == PNUM_USER + 0 ) 128 { 129 _DpaMessage.PeripheralInfoAnswer.PerT = PERIPHERAL_TYPE_USER_AREA; 130 _DpaMessage.PeripheralInfoAnswer.PerTE = PERIPHERAL_TYPE_EXTENDED_READ_WRITE; 131 goto DpaHandleReturnTRUE; 132 } 133 134 break; 135 } 136 // ------------------------------------------------- 137 else 138 { 139 // Handle peripheral command 140 if ( _PNUM == PNUM_USER + 0 ) 141 { 142 switch ( _PCMD ) 143 { 144 // Read data 145 case 0x00: 146 { 147 // No input data 148 if ( _DpaDataLength != 0 ) 149 DpaApiReturnPeripheralError( ERROR_DATA_LEN ); 150 151 // Copy data to the result, the result length is 16 bytes (one AES block) 152 copyMemoryBlock( PeripheralRam, _DpaMessage.Response.PData, _DpaDataLength = 16 ); 153 // Encrypt data (_DpaMessage.Response.PData is actually bufferRF) 154 encryptBufferRF( 1 ); 155 return TRUE; 156 } 157 158 // Write data 159 case 0x01: 160 { 161 // Exactly one AES block of input data is expected 162 if ( _DpaDataLength != 16 ) 163 DpaApiReturnPeripheralError( ERROR_DATA_LEN ); 164 165 // Decrypt data to write (_DpaMessage.Response.PData is actually bufferRF) 166 decryptBufferRF( 1 ); 167 // Copy written data to the buffer 168 copyMemoryBlock( _DpaMessage.Request.PData, PeripheralRam, 16 ); 169 // No data is written 170 _DpaDataLength = 0; 171 return TRUE; 172 } 173 174 // Invalid command 175 default: 176 DpaApiReturnPeripheralError( ERROR_PCMD ); 177 } 178 } 179 } 180 } 181 182 return FALSE; 183 } 184 185 //############################################################################################ 186 // Default Custom DPA Handler header; 2nd include implementing a Code bumper to detect too long code of the Custom DPA Handler (modify the path according to your setup) 187 #include "DPAcustomHandler.h" 188 //############################################################################################