TheArchive/Magisk
1
0
Fork 0
mirror of https://github.com/topjohnwu/Magisk.git synced 2025-12-12 10:05:01 +00:00
Code Issues Packages Projects Releases Wiki Activity

Use stable random seed

Browse Source
This commit is contained in:
vvb2060
2023-03-08 06:52:09 +08:00
committed by John Wu
parent 5117dc1a31
commit 46ce765860
6 changed files with 56 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

61
native/src/base/misc.cpp
View File

@@ -33,23 +33,29 @@ int fork_no_orphan() {
return 0;
}
int gen_rand_str(char *buf, int len, bool varlen) {
constexpr char ALPHANUM[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
static std::mt19937 gen([]{
if (access("/dev/urandom", F_OK) != 0)
mknod("/dev/urandom", 0600 | S_IFCHR, makedev(1, 9));
int fd = xopen("/dev/urandom", O_RDONLY | O_CLOEXEC);
unsigned seed;
xxread(fd, &seed, sizeof(seed));
int gen_rand_str(char *buf, int len, const void *seed_buf, bool varlen) {
static mt19937_64 gen([&] {
mt19937_64::result_type seed;
if (seed_buf == nullptr) {
int fd = xopen("/dev/urandom", O_RDONLY | O_CLOEXEC);
xxread(fd, &seed, sizeof(seed));
close(fd);
} else {
memcpy(&seed, seed_buf, sizeof(seed));
}
return seed;
}());
std::uniform_int_distribution<int> dist(0, sizeof(ALPHANUM) - 2);
if (len == 0)
return 0;
if (varlen) {
std::uniform_int_distribution<int> len_dist(len / 2, len);
len = len_dist(gen);
}
for (int i = 0; i < len - 1; ++i)
buf[i] = ALPHANUM[dist(gen)];
std::uniform_int_distribution<int> alphabet('a', 'z');
for (int i = 0; i < len - 1; ++i) {
buf[i] = static_cast<char>(alphabet(gen));
}
buf[len - 1] = '\0';
return len - 1;
}
@@ -134,19 +140,36 @@ void set_nice_name(const char *name) {
prctl(PR_SET_NAME, name);
}
template<typename T>
static T parse_num(string_view s, int base) {
T acc = 0;
for (char c: s) {
if (isdigit(c)) {
c -= '0';
} else if (base > 10 && isalpha(c)) {
c -= isupper(c) ? 'A' - 10 : 'a' - 10;
} else {
return -1;
}
if (c >= base) {
return -1;
}
acc *= base;
acc += c;
}
return acc;
}
/*
* Bionic's atoi runs through strtol().
* Use our own implementation for faster conversion.
*/
int parse_int(string_view s) {
int val = 0;
for (char c : s) {
if (!c) break;
if (c > '9' || c < '0')
return -1;
val = val * 10 + c - '0';
}
return val;
return parse_num<int>(s, 10);
}
uint64_t parse_uint64_hex(string_view s) {
return parse_num<uint64_t>(s, 16);
}
uint32_t binary_gcd(uint32_t u, uint32_t v) {