NXP

hitag 2 算法 （来源网络）

2019-07-12 12:05发布

站内文章 / NXP MCU
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// Software optimized 48-bit Philips/NXP Mifare Hitag2 PCF7936/46/47/52 stream cipher algorithm by I.C. Wiener 2006-2007. // For educational purposes only. // No warranties or guarantees of any kind. // This code is released into the public domain by its author. #include // Basic macros: #define u8 unsigned char #define u32 unsigned long #define u64 unsigned __int64 #define rev8(x) ((((x)>>7)&1)+((((x)>>6)&1)<<1)+((((x)>>5)&1)<<2)+((((x)>>4)&1)<<3)+((((x)>>3)&1)<<4)+((((x)>>2)&1)<<5)+((((x)>>1)&1)<<6)+(((x)&1)<<7)) #define rev16(x) (rev8 (x)+(rev8 (x>> 8)<< 8)) #define rev32(x) (rev16(x)+(rev16(x>>16)<<16)) #define rev64(x) (rev32(x)+(rev32(x>>32)<<32)) #define bit(x,n) (((x)>>(n))&1) #define bit32(x,n) ((((x)[(n)>>5])>>((n)))&1) #define inv32(x,i,n) ((x)[(i)>>5]^=((u32)(n))<<((i)&31)) #define rotl64(x, n) ((((u64)(x))<<((n)&63))+(((u64)(x))>>((0-(n))&63))) // Single bit Hitag2 functions: #define i4(x,a,b,c,d) ((u32)((((x)>>(a))&1)+(((x)>>(b))&1)*2+(((x)>>(c))&1)*4+(((x)>>(d))&1)*8)) static const u32 ht2_f4a = 0x2C79; // 0010 1100 0111 1001 static const u32 ht2_f4b = 0x6671; // 0110 0110 0111 0001 static const u32 ht2_f5c = 0x7907287B; // 0111 1001 0000 0111 0010 1000 0111 1011 static u32 f20 (const u64 x) { u32 i5; i5 = ((ht2_f4a >> i4 (x, 1, 2, 4, 5)) & 1)* 1 + ((ht2_f4b >> i4 (x, 7,11,13,14)) & 1)* 2 + ((ht2_f4b >> i4 (x,16,20,22,25)) & 1)* 4 + ((ht2_f4b >> i4 (x,27,28,30,32)) & 1)* 8 + ((ht2_f4a >> i4 (x,33,42,43,45)) & 1)*16; return (ht2_f5c >> i5) & 1; } static u64 hitag2_init (const u64 key, const u32 serial, const u32 IV) { u32 i; u64 x = ((key & 0xFFFF) << 32) + serial; for (i = 0; i < 32; i++) { x >>= 1; x += (u64) (f20 (x) ^ (((IV >> i) ^ (key >> (i+16))) & 1)) << 47; } return x; } static u64 hitag2_round (u64 *state) { u64 x = *state; x = (x >> 1) + ((((x >> 0) ^ (x >> 2) ^ (x >> 3) ^ (x >> 6) ^ (x >> 7) ^ (x >> 8) ^ (x >> 16) ^ (x >> 22) ^ (x >> 23) ^ (x >> 26) ^ (x >> 30) ^ (x >> 41) ^ (x >> 42) ^ (x >> 43) ^ (x >> 46) ^ (x >> 47)) & 1) << 47); *state = x; return f20 (x); } // Bitslice Hitag2 functions: #define ht2bs_4a(a,b,c,d) (~(((a|b)&c)^(a|d)^b)) #define ht2bs_4b(a,b,c,d) (~(((d|c)&(a^b))^(d|a|b))) #define ht2bs_5c(a,b,c,d,e) (~((((((c^e)|d)&a)^b)&(c^b))^(((d^e)|a)&((d^b)|c)))) #define uf20bs u32 // choose your own type/width static uf20bs f20bs (const uf20bs *x) { return ht2bs_5c ( ht2bs_4a(x[ 1],x[ 2],x[ 4],x[ 5]), ht2bs_4b(x[ 7],x[11],x[13],x[14]), ht2bs_4b(x[16],x[20],x[22],x[25]), ht2bs_4b(x[27],x[28],x[30],x[32]), ht2bs_4a(x[33],x[42],x[43],x[45])); } static void hitag2bs_init (uf20bs *x, const uf20bs *key, const uf20bs *serial, const uf20bs *IV) { u32 i, r; for (i = 0; i < 32; i++) x[i] = serial[i]; for (i = 0; i < 16; i++) x[32+i] = key[i]; for (r = 0; r < 32; r++) { for (i = 0; i < 47; i++) x[i] = x[i+1]; x[47] = f20bs (x) ^ IV[i] ^ key[16+i]; } } static uf20bs hitag2bs_round (uf20bs *x) { uf20bs y; u32 i; y = x[ 0] ^ x[ 2] ^ x[ 3] ^ x[ 6] ^ x[ 7] ^ x[ 8] ^ x[16] ^ x[22] ^ x[23] ^ x[26] ^ x[30] ^ x[41] ^ x[42] ^ x[43] ^ x[46] ^ x[47]; for (i = 0; i < 47; i++) x[i] = x[i+1]; x[47] = y; return f20bs (x); } // "MIKRON" = O N M I K R // Key = 4F 4E 4D 49 4B 52 - Secret 48-bit key // Serial = 49 43 57 69 - Serial number of the tag, transmitted in clear // Random = 65 6E 45 72 - Random IV, transmitted in clear //~28~DC~80~31 = D7 23 7F CE - Authenticator value = inverted first 4 bytes of the keystream // The code below must print out "D7 23 7F CE 8C D0 37 A9 57 49 C1 E6 48 00 8A B6". // The inverse of the first 4 bytes is sent to the tag to authenticate. // The rest is encrypted by XORing it with the subsequent keystream. static u32 hitag2_byte (u64 * x) { u32 i, c; for (i = 0, c = 0; i < 8; i++) c += (u32) hitag2_round (x) << (i^7); return c; } int main (void) { u32 i; u64 state; state = hitag2_init (rev64 (0x524B494D4E4FUL), rev32 (0x69574349), rev32 (0x72456E65)); for (i = 0; i < 16; i++) printf ("%02X ", hitag2_byte (&state)); printf (" "); return 0; }

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