forked from MarcoBuster/Magisk
51 lines
1.3 KiB
C
51 lines
1.3 KiB
C
#include "magiskboot.h"
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static int hex2int(char c) {
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int first = c / 16 - 3;
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int second = c % 16;
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int result = first * 10 + second;
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if(result > 9) result--;
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return result;
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}
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static unsigned hex2ascii(char c, char d) {
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int high = hex2int(c) * 16;
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int low = hex2int(d);
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return high + low;
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}
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static void hexstr2str(char *hex, unsigned char *str) {
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char buf = 0;
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for(int i = 0, length = strlen(hex); i < length; ++i){
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if(i % 2){
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str[i / 2] = hex2ascii(buf, hex[i]);
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} else{
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buf = hex[i];
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}
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}
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}
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void hexpatch(char * image, char *from, char *to) {
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int fd = open(image, O_RDWR), patternsize = strlen(from) / 2, patchsize = strlen(to) / 2;
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size_t filesize = lseek(fd, 0, SEEK_END);
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lseek(fd, 0, SEEK_SET);
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unsigned char *file, *pattern, *patch;
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file = mmap(NULL, filesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
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pattern = malloc(patternsize);
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patch = malloc(patchsize);
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hexstr2str(from, pattern);
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hexstr2str(to, patch);
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for (size_t i = 0; i < filesize - patternsize; ++i) {
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if (memcmp(file + i, pattern, patternsize) == 0) {
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printf("Pattern %s found!\nPatching to %s\n", from, to);
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memset(file + i, 0, patternsize);
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memcpy(file + i, patch, patchsize);
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i += patternsize - 1;
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}
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}
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munmap(file, filesize);
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free(pattern);
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free(patch);
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close(fd);
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}
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