PN7462 How to calculate 'MAC algorithm 3' by Using CryptoSym Module?

EE_Ark — Wed, 20 Apr 2022 10:41:41 GMT

Hi, I want to calculate Mac3([ISO/IEC 9797-1] MAC algorithm 3 with blockcipher DES, zero IV(8bytes), [ISO / IEC 9797 - 1] padding method 2) by using Cyptosym module of NXP NFC Reader Library.

This is the code i wrote for test, but it does not give the expected result.

uint8_t kMac[16] = {0};

kMac[0] = 0x1C;
kMac[1] = 0x45;
kMac[2] = 0x86;
kMac[3] = 0xCD;
kMac[4] = 0x3E;
kMac[5] = 0xB6;
kMac[6] = 0xE3;
kMac[7] = 0x26;
kMac[8] = 0x1;
kMac[9] = 0x4C;
kMac[10] = 0x61;
kMac[11] = 0xDF;
kMac[12] = 0xD9;
kMac[13] = 0xCD;
kMac[14] = 0x76;
kMac[15] = 0x7F;

uint8_t eifd_Latest[32] = {0};

eifd_Latest[0] = 0xDC;
eifd_Latest[1] = 0xD0;
eifd_Latest[2] = 0xAB;
eifd_Latest[3] = 0xF5;
eifd_Latest[4] = 0x64;
eifd_Latest[5] = 0xCB;
eifd_Latest[6] = 0xF5;
eifd_Latest[7] = 0x3A;
eifd_Latest[8] = 0xF;
eifd_Latest[9] = 0x73;
eifd_Latest[10] = 0x68;
eifd_Latest[11] = 0xCA;
eifd_Latest[12] = 0x4D;
eifd_Latest[13] = 0x3A;
eifd_Latest[14] = 0x6D;
eifd_Latest[15] = 0xFE;
eifd_Latest[16] = 0x6D;
eifd_Latest[17] = 0x89;
eifd_Latest[18] = 0x37;
eifd_Latest[19] = 0x14;
eifd_Latest[20] = 0x15;
eifd_Latest[21] = 0xB8;
eifd_Latest[22] = 0x8B;
eifd_Latest[23] = 0x4B;
eifd_Latest[24] = 0x17;
eifd_Latest[25] = 0x32;
eifd_Latest[26] = 0x91;
eifd_Latest[27] = 0xB0;
eifd_Latest[28] = 0xE4;
eifd_Latest[29] = 0x3B;
eifd_Latest[30] = 0x8;
eifd_Latest[31] = 0x95;

phCryptoSym_Sw_DataParams_t sCryptoEncMac;

phCryptoSym_Sw_Init(&sCryptoEncMac,sizeof(phCryptoSym_Sw_DataParams_t), NULL);

phCryptoSym_SetConfig(&sCryptoEncMac,PH_CRYPTOSYM_CONFIG_KEEP_IV, PH_CRYPTOSYM_VALUE_KEEP_IV_OFF);

phCryptoSym_LoadKeyDirect(&sCryptoEncMac,kMac, PH_CRYPTOSYM_KEY_TYPE_3K3DES);

phCryptoSym_LoadIv(&sCryptoEncMac, iv, 8);

uint8_t maclength;
uint8_t mac[8] = {0};

phCryptoSym_CalculateMac(
&sCryptoEncMac,
(PH_CRYPTOSYM_MAC_MODE_CBCMAC),
&eifd_Latest[0],
32,
&mac[0],
&maclength);

Result MAC sshould be :

0 = 0x18
1 = 0x3E
2 = 0x7
3 = 0x61
4 = 0x55
5 = 0x7E
6 = 0x86
7 = 0xDE

But i am getting different result with above code.

Where could I be doing wrong?

Re: PN7462 How to calculate 'MAC algorithm 3' by Using CryptoSym Module?

danielchen — Sat, 07 May 2022 01:47:35 GMT

Hi EE:

please refer to the description of CryptoSym implementations

Important hints for users of this component:

Before use of any function, the dedicated crypto implementation has to be initialized (e.g. phCryptoSym_Sw_Init)
Functions using a key store (phCryptoSym_LoadKey and phCryptoSym_DiversifyKey) are only available if a key store has been passed during component initialization
Before any cipher operation or MAC operation (phCryptoSym_Encrypt, phCryptoSym_Decrypt, phCryptoSym_CalculateMac) can be used, a key has to be loaded using either phCryptoSym_LoadKey or phCryptoSym_LoadKeyDirect
Before any cipher operation or MAC operation (phCryptoSym_Encrypt, phCryptoSym_Decrypt, phCryptoSym_CalculateMac) can be used, an appropriate IV has to be loaded by calling phCryptoSym_LoadIv
Using phCryptoSym_GetConfig, the block sizes and key lengths for the currently loaded key can be retrieved

Regards

Daniel

NFCのトピックPN7462 How to calculate 'MAC algorithm 3' by Using CryptoSym Module?

PN7462 How to calculate 'MAC algorithm 3' by Using CryptoSym Module?

Re: PN7462 How to calculate 'MAC algorithm 3' by Using CryptoSym Module?