mirror of
https://github.com/topjohnwu/Magisk
synced 2024-11-14 22:28:37 +01:00
79 lines
2.0 KiB
C
79 lines
2.0 KiB
C
/* b64xz.c - Base64-XZ Extractor
|
|
*
|
|
* This program converts data from stdin to stdout.
|
|
* The input should be compressed with xz (integrity check only support CRC32 or none) and then
|
|
* encoded into base64 format. What b64xz does is basically the reverse of the
|
|
* mentioned process: decode base64 to bytes, decompress xz, then dump to stdout
|
|
*
|
|
* The compiled binary will be hex-dumped into update-binary
|
|
* Busybox will be xz-compressed, base64 encoded and dumped into update-binary
|
|
* This program is to recover busybox for Magisk installation environment
|
|
*/
|
|
|
|
#include <unistd.h>
|
|
#include <xz.h>
|
|
|
|
static const char trans_tbl[] =
|
|
"|$$$}rstuvwxyz{$$$$$$$>?@ABCDEFGHIJKLMNOPQRSTUVW$$$$$$XYZ[\\]^_`abcdefghijklmnopq";
|
|
|
|
static void decodeblock(uint8_t* in, uint8_t* out) {
|
|
out[0] = (uint8_t)(in[0] << 2 | in[1] >> 4);
|
|
out[1] = (uint8_t)(in[1] << 4 | in[2] >> 2);
|
|
out[2] = (uint8_t)(((in[2] << 6) & 0xc0) | in[3]);
|
|
}
|
|
|
|
static int unxz(struct xz_dec *dec, const void *buf, unsigned size) {
|
|
uint8_t out[8192];
|
|
struct xz_buf b = {
|
|
.in = buf,
|
|
.in_pos = 0,
|
|
.in_size = size,
|
|
.out = out,
|
|
.out_pos = 0,
|
|
.out_size = sizeof(out)
|
|
};
|
|
enum xz_ret ret;
|
|
do {
|
|
ret = xz_dec_run(dec, &b);
|
|
if (ret != XZ_OK && ret != XZ_STREAM_END)
|
|
return 1;
|
|
write(STDOUT_FILENO, out, b.out_pos);
|
|
b.out_pos = 0;
|
|
} while (b.in_pos != size);
|
|
return 0;
|
|
}
|
|
|
|
int main(int argc, char const* argv[]) {
|
|
if (argc > 1)
|
|
return 0;
|
|
|
|
uint8_t in[4], buf[6144];
|
|
unsigned len = 0, pos = 0;
|
|
int8_t c;
|
|
|
|
xz_crc32_init();
|
|
struct xz_dec *dec = xz_dec_init(XZ_DYNALLOC, 1 << 26);
|
|
if (dec == NULL)
|
|
return 1;
|
|
|
|
while (read(STDIN_FILENO, &c, sizeof(c)) == 1) {
|
|
c = ((c < 43 || c > 122) ? -1 : (trans_tbl[c - 43] == '$' ? -1 : trans_tbl[c - 43] - 62));
|
|
if (c >= 0)
|
|
in[len++] = c;
|
|
if (len < 4)
|
|
continue;
|
|
len = 0;
|
|
decodeblock(in, buf + pos);
|
|
pos += 3;
|
|
if (pos == sizeof(buf)) {
|
|
if (unxz(dec, buf, pos))
|
|
return 1;
|
|
pos = 0;
|
|
}
|
|
}
|
|
if (pos && unxz(dec, buf, pos))
|
|
return 1;
|
|
xz_dec_end(dec);
|
|
return 0;
|
|
}
|