+static des_context ctx_enc = {DES_ENCRYPT,{0}};
+static des_context ctx_dec = {DES_DECRYPT,{0}};
+
+void desdecrypt_iclass(uint8_t *iclass_key, uint8_t *input, uint8_t *output)
+{
+ uint8_t key_std_format[8] = {0};
+ permutekey_rev(iclass_key, key_std_format);
+ des_setkey_dec( &ctx_dec, key_std_format);
+ des_crypt_ecb(&ctx_dec,input,output);
+}
+void desencrypt_iclass(uint8_t *iclass_key, uint8_t *input, uint8_t *output)
+{
+ uint8_t key_std_format[8] = {0};
+ permutekey_rev(iclass_key, key_std_format);
+ des_setkey_enc( &ctx_enc, key_std_format);
+ des_crypt_ecb(&ctx_enc,input,output);
+}
+
+/**
+ * @brief Insert uint8_t[8] custom master key to calculate hash2 and return key_select.
+ * @param key unpermuted custom key
+ * @param hash1 hash1
+ * @param key_sel output key_sel=h[hash1[i]]
+ */
+void hash2(uint8_t *key64, uint8_t *outp_keytable)
+{
+ /**
+ *Expected:
+ * High Security Key Table
+
+00 F1 35 59 A1 0D 5A 26 7F 18 60 0B 96 8A C0 25 C1
+10 BF A1 3B B0 FF 85 28 75 F2 1F C6 8F 0E 74 8F 21
+20 14 7A 55 16 C8 A9 7D B3 13 0C 5D C9 31 8D A9 B2
+30 A3 56 83 0F 55 7E DE 45 71 21 D2 6D C1 57 1C 9C
+40 78 2F 64 51 42 7B 64 30 FA 26 51 76 D3 E0 FB B6
+50 31 9F BF 2F 7E 4F 94 B4 BD 4F 75 91 E3 1B EB 42
+60 3F 88 6F B8 6C 2C 93 0D 69 2C D5 20 3C C1 61 95
+70 43 08 A0 2F FE B3 26 D7 98 0B 34 7B 47 70 A0 AB
+
+**** The 64-bit HS Custom Key Value = 5B7C62C491C11B39 ******/
+ uint8_t key64_negated[8] = {0};
+ uint8_t z[8][8]={{0},{0}};
+ uint8_t temp_output[8]={0};
+ //calculate complement of key
+ int i;
+ for(i=0;i<8;i++)
+ key64_negated[i]= ~key64[i];
+
+ // Once again, key is on iclass-format
+ desencrypt_iclass(key64, key64_negated, z[0]);
+
+ prnlog("\nHigh security custom key (Kcus):");
+ printvar("z0 ", z[0],8);
+
+ uint8_t y[8][8]={{0},{0}};
+
+ // y[0]=DES_dec(z[0],~key)
+ // Once again, key is on iclass-format
+ desdecrypt_iclass(z[0], key64_negated, y[0]);
+ printvar("y0 ", y[0],8);
+
+ for(i=1; i<8; i++)
+ {
+
+ // z [i] = DES dec (rk(K cus , i), z [i−1] )
+ rk(key64, i, temp_output);
+ //y [i] = DES enc (rk(K cus , i), y [i−1] )
+
+ desdecrypt_iclass(temp_output,z[i-1], z[i]);
+ desencrypt_iclass(temp_output,y[i-1], y[i]);
+
+ }
+ if(outp_keytable != NULL)
+ {
+ for(i = 0 ; i < 8 ; i++)
+ {
+ memcpy(outp_keytable+i*16,y[i],8);
+ memcpy(outp_keytable+8+i*16,z[i],8);
+ }
+ }else
+ {
+ printarr_human_readable("hash2", outp_keytable,128);
+ }
+}