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第一次android逆向
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2023-4-11 14:37
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不得不说，我的思维水平一直在低位徘徊，技术水平仍然停留在以前。
就像有家公司，你去面试，他说他对一个人说的话的根本就不感兴趣，他想看看你写的东西，比如博客。我后来才感觉，他是对的，从一个人的字里行间就可以知道他是什么人，他的思维模式，他经历的历史。
大约在2016年，我经历了第一次android逆向的完整过程，非常感谢当时老板的支持，因为我们那时候没人懂这个玩意儿，但是老板的奇思妙想和支持，同事的信任，自己的任性，都为我提供了很多的勇气和毅力来完成这个项目。那时候我一直坚信，我可以重构整个internet，只要我想的话。这种执着给我提供了源源不断的动力，就像在前线、在战场，意志力为一个战士的舞台提供了无与伦比的想象空间。
该程序是一个同步程序，用于备份同步本机和服务器上的通讯录、短信、通话记录等信息。其网络数据全部加密，其解密后核心算法如下：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 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528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 | #include "stdafx.h"unsigned char TeaKey[256] = {0};unsigned char unk_19578[] = {0x44,0x46,0x47,0x00,0x00,0x00,0x00,0x3C,0x3E,0x3C,0x00,0x00,0x00,0x00,0x26,0x2A,0x4D,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x02,0x00,0x06,0x00,0x03,0x00,0x05,0x00,0x04,0x00,0x00 };unsigned char * unk_1957F = unk_19578 + 7;unsigned char * unk_19586 = unk_19578 + 14;unsigned char * unk_1958E = unk_19578 + 22;unsigned char unk_1A43C[] = {0x78,0xA4,0x6A,0xD7,0x56,0xB7,0xC7,0xE8,0xDB,0x70,0x20,0x24,0xEE,0xCE,0xBD,0xC1,0xAF,0x0F,0x7C,0xF5,0x2A,0xC6,0x87,0x47,0x13,0x46,0x30,0xA8,0x01,0x95,0x46,0xFD,0xD8,0x98,0x80,0x69,0xAF,0xF7,0x44,0x8B,0xB1,0x5B,0xFF,0xFF,0xBE,0xD7,0x5C,0x89,0x22,0x11,0x90,0x6B,0x93,0x71,0x98,0xFD,0x8E,0x43,0x79,0xA6,0x21,0x08,0xB4,0x49,//1a47c0x62,0x25,0x1e,0xf6,0x40,0xB3,0x40,0xC0,0x51,0x5A,0x5E,0x26,0xAA,0xC7,0xB6,0xE9,0x5D,0x10,0x2F,0xD6,0x53,0x14,0x44,0x02,0x81,0xE6,0xA1,0xD8,0xC8,0xFB,0xD3,0xE7,0xE6,0xCD,0xE1,0x21,0xD6,0x07,0x37,0xC3,0x87,0x0D,0xD5,0xF4,0xED,0x14,0x5A,0x45,0x05,0xE9,0xE3,0xA9,0xF8,0xA3,0xEF,0xFC,0xD9,0x02,0x6F,0x67,0x8A,0x4C,0x2A,0x8D,0x42,0x39,0xFA,0xFF,0x81,0xF6,0x71,0x87,0x22,0x61,0x9D,0x6D,0x0C,0x38,0xE5,0xFD,0x44,0xEA,0xBE,0xA4,0xA9,0xCF,0xDE,0x4B,0x60,0x4B,0xBB,0xF6,0x70,0xBC,0xBF,0xBE,0xC6,0x7E,0x9B,0x28,0xFA,0x27,0xA1,0xEA,0x85,0x30,0xEF,0xD4,0x05,0x1D,0x88,0x04,0x39,0xD0,0xD4,0xD9,0xE5,0x99,0xDB,0xE6,0xF8,0x7C,0xA2,0x1F,0x65,0x56,0xAC,0xC4,0x44,0x22,0x29,0xF4,0x97,0xFF,0x2A,0x43,0xA7,0x23,0x94,0xAB,0x39,0xA0,0x93,0xFC,0xC3,0x59,0x5B,0x65,0x92,0xCC,0x0C,0x8F,0x7D,0xF4,0xEF,0xFF,0xD1,0x5D,0x84,0x85,0x4F,0x7E,0xA8,0x6F,0xE0,0xE6,0x2C,0xFE,0x14,0x43,0x01,0xA3,0xA1,0x11,0x08,0x4E,0x82,0x7E,0x53,0xF7,0x35,0xF2,0x3A,0xBD,0xBB,0xD2,0xD7,0x2A,0x91,0xD3,0x86,0xEB,//1a53c0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,0x01,0x06,0x0B,0x00,0x05,0x0A,0x0F,0x04,0x09,0x0E,0x03,0x08,0x0D,0x02,0x07,0x0C,0x05,0x08,0x0B,0x0E,0x01,0x04,0x07,0x0A,0x0D,0x00,0x03,0x06,0x09,0x0C,0x0F,0x02,0x00,0x07,0x0E,0x05,0x0C,0x03,0x0A,0x01,0x08,0x0F,0x06,0x0D,0x04,0x0B,0x02,0x09,//1a57c0x07,0x0C,0x11,0x16,0x05,0x09,0x0E,0x14,0x04,0x0B,0x10,0x17,0x06,0x0A,0x0F,0x15,0x98,0x2F,0x8A,0x42,0x91,0x44,0x37,0x71,0xCF,0xFB,0xC0,0xB5,0xA5,0xDB,0xB5,0xE9,0x5B,0xC2,0x56,0x39,0xF1,0x11,0xF1,0x59,0xA4,0x82,0x3F,0x92,0xD5,0x5E,0x1C,0xAB,0x98,0xAA,0x07,0xD8,0x01,0x5B,0x83,0x12,0xBE,0x85,0x31,0x24,0xC3,0x7D,0x0C,0x55,0x74,0x5D,0xBE,0x72,0xFE,0xB1,0xDE,0x80,0xA7,0x06,0xDC,0x9B,0x74,0xF1,0x9B,0xC1,0xC1,0x69,0x9B,0xE4,0x86,0x47,0xBE,0xEF,0xC6,0x9D,0xC1,0x0F,0xCC,0xA1,0x0C,0x24,0x6F,0x2C,0xE9,0x2D,0xAA,0x84,0x74,0x4A,0xDC,0xA9,0xB0,0x5C,0xDA,0x88,0xF9,0x76,0x52,0x51,0x3E,0x98,0x6D,0xC6,0x31,0xA8,0xC8,0x27,0x03,0xB0,0xC7,0x7F,0x59,0xBF,0xF3,0x0B,0xE0,0xC6,0x47,0x91,0xA7,0xD5,0x51,0x63,0xCA,0x06,0x67,0x29,0x29,0x14,0x85,0x0A,0xB7,0x27,0x38,0x21,0x1B,0x2E,0xFC,0x6D,0x2C,0x4D,0x13,0x0D,0x38,0x53,0x54,0x73,0x0A,0x65,0xBB,0x0A,0x6A,0x76,0x2E,0xC9,0xC2,0x81,0x85,0x2C,0x72,0x92,0xA1,0xE8,0xBF,0xA2,0x4B,0x66,0x1A,0xA8,0x70,0x8B,0x4B,0xC2,0xA3,0x51,0x6C,0xC7,0x19,0xE8,0x92,0xD1,0x24,0x06,0x99,0xD6,0x85,0x35,0x0E,0xF4,0x70,0xA0,0x6A,0x10,0x16,0xC1,0xA4,0x19,0x08,0x6C,0x37,0x1E,0x4C,0x77,0x48,0x27,0xB5,0xBC,0xB0,0x34,0xB3,0x0C,0x1C,0x39,0x4A,0xAA,0xD8,0x4E,0x4F,0xCA,0x9C,0x5B,0xF3,0x6F,0x2E,0x68,0xEE,0x82,0x8F,0x74,0x6F,0x63,0xA5,0x78,0x14,0x78,0xC8,0x84,0x08,0x02,0xC7,0x8C,0xFA,0xFF,0xBE,0x90,0xEB,0x6C,0x50,0xA4,0xF7,0xA3,0xF9,0xBE,0xF2,0x78,0x71,0xC6};unsigned char * unk_1A47C = unk_1A43C + 0x40;unsigned char * unk_1A53C = unk_1A43C + 0x100;unsigned char * unk_1A57C = unk_1A43C + 0x140;int __fastcall sub_144C8(int result, unsigned int a2) //52,packet size/4{ char v2 = 0; // nf@0 int v3; // r12@1 int v4; // r3@4 char v5; // r0@8 unsigned int v6; // r1@8 unsigned int v7; // r2@8 bool v8; // zf@17 v3 = result ^ a2; if ( a2 <= 0 ) a2 = -a2; if ( a2 == 1 ) { if ( (v3 ^ result) < 0 ) result = -result; return result; } else { v4 = result; if ( result < 0 ) v4 = -result; if ( v4 <= a2 ) { if ( v4 < a2 ) result = 0; if ( v4 == a2 ) result = (v3 >> 31) | 1; } else if ( a2 & (a2 - 1) ) { //v5 = __clz(a2) - __clz(v4); __asm { pushad mov eax,a2 bsr ecx,eax mov edx,32 sub edx,ecx sub edx,1 mov ebx,edx mov eax,v4 bsr ecx,eax mov edx,32 sub edx,ecx sub edx,1 sub ebx,edx mov v5,bl popad } v6 = a2 << v5; v7 = 1 << v5; result = 0; while ( 1 ) { if ( v4 >= v6 ) { v4 -= v6; result |= v7; } if ( v4 >= v6 >> 1 ) { v4 -= v6 >> 1; result |= v7 >> 1; } if ( v4 >= v6 >> 2 ) { v4 -= v6 >> 2; result |= v7 >> 2; } if ( v4 >= v6 >> 3 ) { v4 -= v6 >> 3; result |= v7 >> 3; } v8 = v4 == 0; if ( v4 ) { v7 >>= 4; v8 = v7 == 0; } if ( v8 ) break; v6 >>= 4; } if ( v3 < 0 ) result = -result; } else { int Tmp = 0; __asm { pushad mov eax,a2 bsr ecx,eax mov edx,32 sub edx,ecx sub edx,1 mov Tmp,edx popad } result = (unsigned int)v4 >> (31 - Tmp); //result = (unsigned int)v4 >> (31 - __clz(a2)); if ( result < 0 ) result = -result; } } return result;}int __fastcall sub_144C0(int a1, int a2) // 52, packet size{ if ( !a2 ) return 0; //JUMPOUT(&loc_152A0); return sub_144C8(a1, a2);}int __fastcall sub_B764(unsigned int a1, unsigned int a2, int a3) //a1 = key a2 = 64, a3 = int [] return by c160{ int v3; // r4@1 int v4; // r5@1 int v5; // r3@1 int v6; // r6@1 int v7; // r3@1 int v8; // r1@4 unsigned int v9; // r2@4 int v10; // r4@4 int *v11; // r3@4 int v12; // r2@5 int v13; // r0@5 int v14; // r1@5 int v15; // r6@5 int v16; // r3@5 int v17; // r4@7 int v18; // r4@8 int v19; // r6@8 int v20; // r3@8 int v21; // r2@10 char v22; // r6@10 int v23; // r2@10 int v24; // r2@10 int v25; // r3@11 int v26; // r5@11 int v27; // r0@13 int v28; // r5@13 int v29; // r0@13 int v30; // r3@14 int v31; // r5@14 int v32; // r1@16 int v33; // r5@16 int v34; // r1@16 int result; // r0@18 int v36; // r2@20 int v37; // r1@20 int v38; // r3@20 int v39; // r4@20 int v41; // [sp+4h] [bp+4h]@5 int v42; // [sp+8h] [bp+8h]@3 int v43; // [sp+Ch] [bp+Ch]@3 int v44; // [sp+10h] [bp+10h]@1 int v45; // [sp+14h] [bp+14h]@11 int v46; // [sp+18h] [bp+18h]@3 int v47; // [sp+1Ch] [bp+1Ch]@1 int v48; // [sp+20h] [bp+20h]@1 int v49; // [sp+24h] [bp+24h]@1 int v50; // [sp+28h] [bp+28h]@1 unsigned int v51; // [sp+2Ch] [bp+2Ch]@3 int v52; // [sp+30h] [bp+30h]@7 int v53; // [sp+34h] [bp+34h]@3 int v54[17]; // [sp+38h] [bp+38h]@19 ////////////////////////////////////////////////////////////////////////// v44 = a1 + 4 * (a2 >> 2); v3 = *(_DWORD *)(a3 + 4); v4 = *(_DWORD *)(a3 + 8); v50 = *(_DWORD *)a3; v5 = *(_DWORD *)(a3 + 16); v6 = *(_DWORD *)(a3 + 12); v49 = v3; v7 = a2 + v5; v48 = v4; v47 = v6; *(_DWORD *)(a3 + 16) = v7; if ( v7 < a2 ) ++*(_DWORD *)(a3 + 20); v51 = a1; v46 = (int)unk_1A53C; ////////////////////////////////////////////////////////////////////////// v53 = (int)&v54[16]; ////////////////////////////////////////////////////////////////////////// v43 = (int)unk_1A57C; ////////////////////////////////////////////////////////////////////////// v42 = a3; int Tmp = (int)v54; while ( 1 ) { result = v44; if ( v51 >= v44 ) break; v9 = v51; v11 = v54; do { v8 = *(_DWORD *)v9; v9 += 4; v10 = v53; *v11 = v8; ++v11; //将16字节数据和接下来的原始密钥拷贝到此处 } while ( v11 != (int *)v10 ); v12 = v47; v51 += 64; v13 = v48; v14 = v49; v15 = v50; v16 = 0; v41 = (int)unk_1A53C; while ( 1 ) { v52 = (v12 ^ v13) & v14 ^ v12; //顺序正确 v52 += *((_DWORD *)unk_1A43C + v16) + v15 + *(DWORD*)((DWORD*)Tmp + *(_BYTE *)(v16 + v41) ); ////////////////////////////////////////////// v17 = __ROR4__(v52, 32 - *(_BYTE *)(v41 + 64 + (v16++ & 3))); if ( v16 == 16 ) break; v15 = v12; v12 = v13; v13 = v14; v14 += v17; } v18 = v17 + v14; v19 = v12; v20 = 0; while ( 1 ) { v21 = ((v14 ^ v18) & v13 ^ v14) + v19 + *((_DWORD *)unk_1A43C + v20 + 16) + *(DWORD*)((DWORD*)Tmp + *(_BYTE *)(v46 + v20 + 16)); v22 = *(_BYTE *)(v43 + (v20++ & 3) + 4); v23 = __ROR4__(v21, 32 - v22); v24 = v23 + v18; if ( v20 == 16 ) break; v19 = v13; v13 = v14; v14 = v18; v18 = v24; } v45 = (int)unk_1A57C; v25 = 0; v26 = v13; while ( 1 ) { v27 = (v18 ^ v24 ^ v14) + v26 + *((_DWORD *)unk_1A43C + v25 + 32); v52 = v27; v52 = v27 + *(DWORD*)((DWORD*)Tmp + *((_BYTE *)unk_1A53C + v25 + 32) ); v27 = (v27 & 0xffffff00) + *(_BYTE *)(v45 + (v25++ & 3) + 8); v28 = __ROR4__(v52, 32 - v27); v29 = v28 + v24; if ( v25 == 16 ) break; v26 = v14; v14 = v18; v18 = v24; v24 = v29; } v45 = (int)unk_1A57C; v30 = 0; v31 = v14; while ( 1 ) { v32 = ((~v18 | v29) ^ v24) + v31 + *((_DWORD *)unk_1A43C + v30 + 48); v52 = v32; v52 = v32 + *(DWORD*)((DWORD*)Tmp + *((_BYTE *)unk_1A53C + v30 + 48) ); v32 = (v32 & 0xffffff00) + *(_BYTE *)(v45 + (v30++ & 3) + 12); v33 = __ROR4__(v52, 32 - v32); v34 = v33 + v29; if ( v30 == 16 ) break; v31 = v18; v18 = v24; v24 = v29; v29 = v34; } v50 += v18; v49 += v34; v48 += v29; v47 += v24; } ////////////////////////////////////////////////////////////////////////// v36 = v42; v37 = v50; v38 = v49; v39 = v48; *(_DWORD *)(v42 + 12) = v47; *(_DWORD *)v36 = v37; *(_DWORD *)(v36 + 4) = v38; *(_DWORD *)(v36 + 8) = v39; return result;}int __fastcall sub_C160(int result){ *(_DWORD *)result = 1732584193; *(_DWORD *)(result + 4) = -271733879; *(_DWORD *)(result + 8) = -1732584194; *(_DWORD *)(result + 12) = 271733878; *(_DWORD *)(result + 20) = 0; *(_DWORD *)(result + 16) = 0; *(_DWORD *)(result + 24) = 0; //C190拷贝原始密钥到后面的字节中 return result;}//将原始密钥传入C160返回的数组中的第28开始的字节中void *__fastcall sub_C190(void *result, int a2, unsigned int a3) //int[] return by c160 ,key,keylen{ int v3; // r6@1 int v4; // r5@3 int v5; // r5@6 unsigned int v6; // r4@7 int v7; // r5@7 unsigned int v8; // [sp+4h] [bp+4h]@1 const void *src; // [sp+8h] [bp+8h]@1 int n; // [sp+Ch] [bp+Ch]@1 int na; // [sp+Ch] [bp+Ch]@4 v3 = (int)result; src = (const void *)a2; v8 = a3; n = a3; if ( a3 << 26 ) { v4 = *((_DWORD *)result + 6); if ( v4 ) { na = a3; if ( a3 > 128 - v4 ) na = 128 - v4; result = memcpy((char *)result + v4 + 28, (const void *)a2, na); v5 = na + v4; *(_DWORD *)(v3 + 24) += na; if ( (unsigned int)v5 > 0x40 ) { v6 = v3 + (v5 & 0xFFFFFFC0); sub_B764(v3 + 28, v5 & 0xFFFFFFC0, v3); v7 = v5 & 0x3F; result = memcpy((void *)(v3 + 28), (const void *)(v6 + 28), v7); *(_DWORD *)(v3 + 24) = v7; } src = (char *)src + na; n = v8 - na; } if ( n > 64 ) { result = (void *)sub_B764((unsigned int)src, n & 0xFFFFFFC0, v3); src = (char *)src + (n & 0xFFFFFFC0); n &= 0x3Fu; } if ( n > 0 ) { result = memcpy((void *)(v3 + 28), src, n); *(_DWORD *)(v3 + 24) = n; } } else { result = (void *)sub_B764(a2, a3, (int)result); } return result;}//低位是C160 C190制造的密钥，高位指向一个整数 a2是一个整数__int64 __fastcall sub_C250(__int64 a1, int a2) //完成密钥的生成和复制，参数为两个地址{ int _8; // ST08_4@1 unsigned int v3; // r5@1 int v4; // r4@1 int v5; // r3@1 int v6; // r6@1 signed int v7; // r3@3 int v8; // r5@5 int v9; // r3@5 __int64 _0; // [sp+0h] [bp+0h]@1 _0 = a1; _8 = a2; v3 = *(_DWORD *)(a1 + 24); //原始密钥长度21// v4 = a1; v5 = v3 + *(_DWORD *)(a1 + 16); //21 v6 = HIDWORD(a1); //数组 *(_DWORD *)(a1 + 16) = v5; //0 if ( v5 < v3 ) ++*(_DWORD *)(a1 + 20); v7 = 120; if ( v3 <= 0x37 ) v7 = 56; HIDWORD(_0) = v7 - v3; //35 memset((void *)(a1 + v3 + 28), 0, v7 - v3); *(_BYTE *)(v4 + v3 + 28) = -128; v8 = HIDWORD(_0) + v3; v9 = v4 + v8; *(_DWORD *)(v9 + 28) = 8 * *(_DWORD *)(v4 + 16); *(_DWORD *)(v9 + 32) = *(_QWORD *)(v4 + 16) >> 29; sub_B764(v4 + 28, v8 + 8, v4); *(_DWORD *)v6 = *(_DWORD *)v4; //返回真实的密钥 key, 64 ,16 bytes params *(_DWORD *)(v6 + 4) = *(_DWORD *)(v4 + 4); *(_DWORD *)(v6 + 8) = *(_DWORD *)(v4 + 8); *(_DWORD *)(v6 + 12) = *(_DWORD *)(v4 + 12); return _0;}int __fastcall sub_C2C4(const void *a1, unsigned int a2, void *a3) //a1== key, a2 == keylen, a3 == int[] { void *v3; // r6@1 unsigned int v4; // r5@1 int result; // r0@1 unsigned __int64 v6; // r2@1 __int64 v7; // r0@3 void * v8 = a3; // r2@3 //V8初始化为A3 const void *src; // [sp+4h] [bp+4h]@1 int v10[0x100]; // [sp+8h] [bp+8h]@3 ////////////////////////////////////////////////////////////////////////// v3 = a3; src = a1; v4 = a2; //v11 = _stack_chk_guard; result = (int)memset(a3, 0, 0x10); v6 = __PAIR__((unsigned int)src, (unsigned int)src) - __PAIR__((unsigned int)((char *)src - 1), 1); //此处编译有问题 if ( (signed int)v4 > 16 && HIDWORD(v6) ) { sub_C160((int)v10); ////////////////////////////////////////////////////////////////////////// sub_C190(v10, (int)src, v4); ////////////////////////////////////////////////////////////////////////// LODWORD(v7) = (unsigned int)v10; HIDWORD(v7) = (unsigned int)v3; result = sub_C250(v7, (int)v8); //低位是C160 C190制造的密钥，根据汇编V8指向a3 } else if ( (signed int)v4 > 0 && HIDWORD(v6) ) { result = (int)memcpy(v3, src, v4); }// if ( v11 != _stack_chk_guard )// _stack_chk_fail(result); return result;}// 14FC: using guessed type int __fastcall _stack_chk_fail(_DWORD);unsigned int __fastcall sub_C340(void *src, size_t n, int a3, int a4, void *dest, int a6){ unsigned int v6; // r6@11 int v7; // r4@8 unsigned int v8; // r3@9 unsigned int v9; // r12@9 char *v10; // r2@10 int v11; // r0@11 int v12; // r4@11 int v13; // r6@11 int v14; // r1@12 signed int v15; // r3@15 int v16; // r4@16 bool v17; // cf@16 unsigned int v19; // [sp+0h] [bp+0h]@11 int v20; // [sp+4h] [bp+4h]@9 unsigned int v21; // [sp+8h] [bp+8h]@11 char *v22; // [sp+Ch] [bp+Ch]@9 unsigned int v23; // [sp+10h] [bp+10h]@10 int v24; // [sp+14h] [bp+14h]@9 int v25; // [sp+18h] [bp+18h]@1 int v26; // [sp+1Ch] [bp+1Ch]@12 int v27[0x100] = {0}; // [sp+20h] [bp+20h]@8 //此处应该是个数组 //v19 = (int)(v27-8); //memmove((char*)v35,"\xf1\x5e\x78\xd2\x30\x33\xc2\xc4\xba\xc8\xa0\x25\x67\x7e\x86\x3a",16); v6 = n; v26 = a3; v25 = a4; if ( (signed int)n <= 0 || !src ) return 0; if ( n << 30 ) //长度为4的倍数 return -32227; if ( !dest ) return v6; if ( a6 < (signed int)n ) return -32227; if ( dest != src ) //这里肯定相等 memcpy(dest, src, n); sub_C2C4((const void *)v26, v25, v27); //v27 is int[] v26 = v6 >> 2; v25 = (v6 >> 2) - 1; v7 = *(_DWORD *)dest; if ( v25 <= 0 ) { v15 = 3; do { v16 = __ROR4__(v7 - (*((int*)v27 + v15) ^ 0x9E3779B9), 16); v7 = v16 ^ 0x79B99E37; v17 = (unsigned int)v15-- >= 1; } while ( v17 ); *(_DWORD *)dest = v7; } else { v24 = sub_144C0(52, v26); v8 = -1640531527 * (v24 + 6); v9 = v6; v22 = (char *)dest + 4 * v25; v20 = 4 * (v26 + 0x3FFFFFFF); while ( v24 != -6 ) { v23 = (v8 >> 2) & 3; v10 = (char *)dest + v20; v26 = v25; do { v21 = (*(v27 + (v26 & 3 ^ v23) ) ^ *((_DWORD *)v10 - 1)) + (v7 ^ v8); v19 = ((unsigned int)v7 >> 3) ^ 16 * *((_DWORD *)v10 - 1); v11 = (v19 + (4 * v7 ^ (*((_DWORD *)v10 - 1) >> 5))) ^ v21; v12 = *(_DWORD *)v10; --v26; v13 = v26; v7 = v12 - v11; *(_DWORD *)v10 = v7; v10 -= 4; } while ( v13 ); v7 = *(_DWORD *)dest - (((16 * *(_DWORD *)v22 ^ ((unsigned int)v7 >> 3)) + ((*(_DWORD *)v22 >> 5) ^ 4 * v7)) ^ ((v7 ^ v8) + (*(_DWORD *)v22 ^ *(v27 + v23)))); v14 = v24 - 1; *(_DWORD *)dest = v7; v8 += 1640531527; v24 = v14; } v6 = v9; } return v6;}unsigned int __fastcall sub_C49C(void *a1, int a2, int a3, int a4, void *a5, int a6) { unsigned int result; // r0@1 int v7; // r3@3 result = sub_C340(a1, a2, a3, a4, a5, a6); if ( (signed int)result > 0 && a5 ) { v7 = *(_DWORD *)((char *)a5 + result - 4); if ( v7 < 0 || (signed int)(result - 3) <= v7 ) { result = -32227; } else { *((_BYTE *)a5 + v7) = 0; result = v7; } } return result;}//src == dest == packet, a2== a6 == pack len, a3 = key, a4 = keylenint __fastcall sub_C4D8(void *src, int a2, int a3, int a4, void *dest, int a6) { int v6; // r5@3 size_t i; // r2@8 unsigned int v8; // r3@11 char *v9; // r6@11 unsigned int v10; // r5@11 unsigned int v11; // r3@12 void *v12; // r1@13 unsigned int v13; // r3@13 int v14; // r2@13 unsigned int v15; // r12@13 int v16; // r0@14 int v17; // r3@14 int v18; // r3@14 unsigned int v19; // r0@14 int v20; // r0@14 unsigned int v21; // r2@15 int v22; // r1@15 int *v23; // r2@18 int v24; // r6@19 int v25; // r3@19 unsigned int v28; // [sp+4h] [bp+4h]@14 size_t v29; // [sp+8h] [bp+8h]@12 unsigned int v30; // [sp+Ch] [bp+Ch]@14 unsigned int v31; // [sp+10h] [bp+10h]@13 int v32; // [sp+14h] [bp+14h]@1 size_t v33; // [sp+18h] [bp+18h]@1 size_t n; // [sp+1Ch] [bp+1Ch]@1 int v35[0x10] = {0}; // [sp+20h] [bp+20h]@11 //memmove((char*)v35,"\xf1\x5e\x78\xd2\x30\x33\xc2\xc4\xba\xc8\xa0\x25\x67\x7e\x86\x3a",16); n = a2; v33 = a3; v32 = a4; if ( a2 > 0 && src ) { v6 = (a2 + 3) & 0xFFFFFFFC; if ( dest ) { if ( a6 >= v6 ) { if ( dest != src ) memcpy(dest, src, n); for ( i = n; (signed int)i < v6; ++i ) *((_BYTE *)dest + i) = 0; n = i; sub_C2C4((const void *)v33, v32, v35); v8 = *(_DWORD *)dest; v9 = (char *)dest + 4 * ((n >> 2) - 1); v33 = (n >> 2) - 1; v10 = *(_DWORD *)v9; if ( (signed int)v33 <= 0 ) { v23 = v35; do { v24 = *v23; ++v23; v25 = __ROR4__(v8, 16); v8 = (v24 ^ 0x9E3779B9) + (v25 ^ 0x9E3779B9); } while ( v23 != &v35[4] ); *(_DWORD *)dest = v8; } else { v32 = sub_144C0(52, n >> 2); v11 = 0; v29 = v33 & 3; while ( v32 != -6 ) { v12 = dest; v13 = v11 - 1640531527; //0xffffffff9E3779B9 v31 = (v13 >> 2) & 3; v14 = 0; v15 = v13; do { //v27 = 0; v16 = *(DWORD*)(v35 + (v14 & 3 ^ v31) ); v17 = *(_DWORD *)((_DWORD *)v12 + 1); ++v14; v30 = v16 ^ v10; v18 = (v16 ^ v10) + (v17 ^ v15); v19 = *((_DWORD *)v12 + 1); v30 = v18; v28 = 16 * v10 ^ (v19 >> 3); v10 = ((v28 + ((v10 >> 5) ^ 4 * v19)) ^ v18) + *(_DWORD *)v12; v20 = v33; *(_DWORD *)v12 = v10; v12 = (char *)v12 + 4; } while ( v14 < v20 ); v21 = *(_DWORD *)dest; v11 = v15; v30 = (*(_DWORD *)dest >> 3) ^ 16 * v10; v10 = ((v30 + (4 * v21 ^ (v10 >> 5))) ^ ((v10 ^ *(v35 + (v31 ^ v29) )) + (v21 ^ v15))) + *(_DWORD *)v9; v22 = v32; *(_DWORD *)v9 = v10; v32 = v22 - 1; } } v6 = n; } else { v6 = -32226; }// Utf8ToGB2312((char*)dest,v6); } } else { v6 = 0; } return v6;}int __fastcall sub_C62C(void *src, int a2, int a3, int a4, void *dest, int a6){ int v6; // r6@1 int v7; // r5@1 int i; // r1@5 int v10; // [sp+8h] [bp+0h]@1 int v11; // [sp+Ch] [bp+4h]@1 v10 = a4; v6 = a2; v11 = a3; v7 = ((a2 + 3) & 0xFFFFFFFC) + 4; if ( dest ) { if ( a6 < v7 ) { v7 = -1; } else { if ( dest != src ) memcpy(dest, src, a2); for ( i = v6; i < v7; ++i ) *((_BYTE *)dest + i) = 0; *((_DWORD *)dest + (i >> 2) - 1) = v6; v7 = sub_C4D8(dest, i, v11, v10, dest, i); } } return v7;}int __fastcall sub_183C(char * str,int strlen,char * key, int keylen, char * decbuf, int decbuflen,int Flag){ int Cnt = 0; if ( Flag ) Cnt = sub_C62C(str, strlen, (int)key, keylen, decbuf, decbuflen); else Cnt = sub_C49C(str, strlen, (int)key, keylen, decbuf, decbuflen); if (Cnt <= 0) { return 0; } return Cnt;}// void __cdecl New_sub_16f4()// {// __asm// {// //push edi// //push esi// //push ebx// push ebp// mov ebp,esp// sub esp,0x7c// // push 64// push 0// push offset TeaKey// call memset// add esp ,12//// push dword ptr 0x7c// push dword ptr 0// push esp// call memset// add esp,12// add esp,0x20//// mov ebx, esp// add ebx ,8// // push 4// push offset unk_19578// mov eax, ebx// add eax,0x1f// push eax// call memcpy// add esp,12////// mov eax,0x252423// mov [ebx + 0x54 - 0x3c], eax // mov eax, offset unk_19578// mov [ebx + 0x54 - 0x50],eax // mov ax,0x235e// mov [ebx + 0x54 - 0x2e],ax // mov ax,0x25// mov [ebx + 0x54 - 0x2c],ax //// push 4// mov eax,offset unk_19578// add eax, 7// push eax// mov eax,ebx// add eax,0x2d// push eax// call memcpy// add esp,12//// mov eax,0x475224// mov [ebx + 0x54 - 0x20],eax//// push 4// mov eax,offset unk_19578// add eax,0x0e// push eax// mov eax,ebx// add eax,0x3b// push eax// call memcpy// add esp,12////// mov ax,0x5248// mov [ebx + 0x42],ax// mov ax,0x28// mov [ebx + 0x42 + 2],ax//// push 0x0e// mov eax,offset unk_19578// add eax, 0x16// push eax// mov eax,ebx// add eax,8// push eax// call memcpy// add esp,12//// sub esp,0x20// //push 0x20// //push 0// //push esp// //call memset// //add esp,12//// mov esi,esp// add esi,8//// lea esi,TeaKey// // push esi//// mov [ebx + 0x54 - 0x50],esi// mov edi,ebx// add edi,0x18////// //r0 =esp - 0x20 + 8 == esi// mov edx,0// SetKey:// push esi//// mov ecx,8// add ecx,edx// movzx eax,word ptr [ebx + ecx]// add edx,2//// mov ecx,eax// shl eax,1// add eax,ecx// add esi,eax//// mov cl,[edi]// mov [esi ],cl// mov cl,[edi+1]// mov [esi + 1],cl// mov cl, [edi + 2]// mov [esi + 2],cl// add edi,7//// pop esi// cmp edx, 0x0e// jnz SetKey//// pop eax// mov esp,ebp// pop ebp// // //pop ebx// //pop esi// //pop edi // //retn 0// }//// return ;// }int AscToHex(unsigned char * Asc,int AscLen, unsigned char * Hex){ unsigned char Table[] = "0123456789abcdef"; unsigned int Index = 0; unsigned int Cnt = 0; unsigned int Counter = 0; unsigned char Tmp = 0; for (Cnt = 0; Cnt < AscLen; ) { for (Index = 0; Index < 16; Index ++) { if ( Asc[Cnt] == Table[Index] ) { Tmp = Index << 4; } } Cnt ++; for (Index = 0; Index < 16; Index ++) { if ( Asc[Cnt] == Table[Index] ) { Tmp = Tmp | Index; } } Cnt ++; Hex[Counter] = Tmp; Counter ++ ; } return Counter;} |
上面的接口很简单，入口是sub_183C，最后的Flag字段代表要不要做md5验证，如果要的话，执行sub_C49C，否则执行sub_C62C函数。其中的sub_C2C4调用sub_C160和sub_C160，这几个函数的作用是计算md5值。sub_C340是主要加解密函数，其中的数学原理本文不做进一步研究。有些细节我也是模棱两可，只是照抄ida的反汇编后的伪C代码。
这个项目是我经历过难度最大最复杂的工程。
逆向过程持续了差不多一个月的时间，从java层smali插桩输入日志、观察参数，推导数据执行流程，到so层ARM反汇编过程。刚开始做的最频繁的，还是smali插桩分析。因为android程序用的arm汇编，解密程序是x86机器，需要将有些Arm汇编翻译为x86指令。
而在so层面，除了少量arm指令代码，将ida的伪代码直接拷贝到vs工程里编译是ok的，但在运行时解密结果是错的，因为这个原因，自己卡在这里好多天，后来偶然的机会纠正了这个错误，以至于到后来，到底是伪c代码和arm转x86汇编部分，哪里错了我都不记得了。
因为整个通信基本上都是加密数据通信，java层封装的各种加解密接口非常之多，我只能挑选某些地方插桩，最后找到从java层的native接口到进入so的入口：
该程序的so库文件罗列如下：
本程序第一个数据包的解密密钥："DFG#$%^#%$RGHR(&*M<><"，解密算法sub_183C。第一个pos或者get数据包中去掉http包头后，数据部分用这个密钥解密后，可以得到客户端登录信息，比如IMEI,IMSI,手机号等。同时，该数据包中还有一个密钥，该密钥用于解密服务器返回的数据包，结构的名称是“GetUserIdentity”，前缀一般是"\x0b\x8c\x98\x0c\xa8\x0c"，是一个tlv数据结构，具体含义不明。
服务器端返回的数据包中包含另一个16(或许是21)字节的密钥，他所在的格式名称是“GetUserIdentityResp”，解密算法也是sub_183C。该密钥是字符串格式化的，需要转化为二进制后用到上的密钥解密，解密之后的16个字节就是通信过程中通讯录的密钥datakey。
当客户端和服务器通讯录同步时，先用密钥"DFG#$%^#%$RGHR(&*M<><"调用sub_183C函数解密，然后利用上面的密钥datakey再次调用sub_183C函数，对第一次解密后的数据再次解密，即可得到明文数据。
解密后的数据如下：
该程序所有的文本数据都是先转化为utf8和base64，然后先加密后压缩传输的。
其中的base64编码：
44CQ6YKu5YKo6ZO26KGM44CR5oKo5bC+5Y+3OTc4OeeahOmTtuihjOWNoeato+WcqOeUs+ivt+W8gOmAmumCruWCqOmTtuihjOaUr+S7mOWuneW/q+aNt+aUr+S7mO+8jOmqjOivgeegge+8mjQ2NzA5NO+8jOW/q+aNt+aUr+S7mOWPr+iDveS8muW4puadpei+g+mrmOeahOi1hOmHkeaNn+WksemjjumZqe+8jOivt+iwqOaFjuaTjeS9nOOAglvlt6XkvZzkurrlkZjkuI3kvJrntKLlj5bvvIzor7fli7/ms4TpnLJd
解码后是：【邮储银行】您尾号9789的银行卡正在申请开通邮储银行支付宝快捷支付，验证码：467094，快捷支付可能会带来较高的资金损失风险，请谨慎操作。[工作人员不会索取，请勿泄露]
自此，整个程序逆向的框架基本完毕。其中有个java层smali插桩的问题，那会刚接触android，但并不知道有个叫做xposed的神器，因此都是每次手动编写java，反汇编为smali后，将之插入到apk反汇编后的smali中，再次对apk的smali打包并签名，最后安装运行。
该程序还有一个孪生兄弟程序，叫做xxx电话本。该程序还有一个大名鼎鼎的大哥程序，叫做xxx信。他们初始化密钥相同：@#%^SEF#$Sddhfvh，而且解密过程更简单，数据解压缩后直接调用sub_183C函数即可。
当时的版本号是6.0.0，但是不到一年之后，程序进行了更新，改为了RSA非对称方式加解密，因此此算法早已彻底失效。
程序样本在附件中可下载。
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最后于 2023-4-21 09:58
被satadrover编辑
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