Magisk/native/jni/magiskboot/pattern.cpp
2021-05-10 18:38:30 -07:00

65 lines
1.6 KiB
C++

#include <utils.hpp>
#include "magiskboot.hpp"
#define MATCH(p) else if (strncmp(s + skip, p, sizeof(p) - 1) == 0) skip += (sizeof(p) - 1)
static int skip_verity_pattern(const char *s) {
int skip = s[0] == ',';
if (0) {}
MATCH("verifyatboot");
MATCH("verify");
MATCH("avb_keys");
MATCH("avb");
MATCH("support_scfs");
MATCH("fsverity");
else return -1;
if (s[skip] == '=') {
while (!strchr(" \n,", s[skip]))
++skip;
}
return skip;
}
static int skip_encryption_pattern(const char *s) {
int skip = s[0] == ',';
if (0) {}
MATCH("forceencrypt");
MATCH("forcefdeorfbe");
MATCH("fileencryption");
else return -1;
if (s[skip] == '=') {
while (!strchr(" \n,", s[skip]))
++skip;
}
return skip;
}
static uint32_t remove_pattern(char *src, uint32_t size, int(*pattern_skip)(const char *)) {
int orig_sz = size;
int write = 0;
for (int read = 0; read < orig_sz;) {
if (int skip = pattern_skip(src + read); skip > 0) {
fprintf(stderr, "Remove pattern [%.*s]\n", skip, src + read);
size -= skip;
read += skip;
} else {
src[write++] = src[read++];
}
}
memset(src + write, 0, orig_sz - write);
return size;
}
uint32_t patch_verity(void *buf, uint32_t size) {
return remove_pattern(static_cast<char *>(buf), size, skip_verity_pattern);
}
uint32_t patch_encryption(void *buf, uint32_t size) {
return remove_pattern(static_cast<char *>(buf), size, skip_encryption_pattern);
}