Wireguard-tools.js/addon/genKey/wgkeys.cpp
Matheus Sampaio Queiroga a0c5e7e513
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Droping rebory and migrate to cmake-js (#14)
- Migrate to cmake-js
- Fix and pretty userspace in go binding
- fix typescript code
Reviewed-on: https://sirherobrine23.org/Wireguard/Wireguard-tools.js/pulls/14
Co-authored-by: Matheus Sampaio Queiroga <srherobrine20@gmail.com>
Co-committed-by: Matheus Sampaio Queiroga <srherobrine20@gmail.com>
2024-07-09 00:07:04 -03:00

345 lines
9.1 KiB
C++

#include "wgkeys.hh"
#include <errno.h>
#include <fcntl.h>
#include <iostream>
#include <random>
#include <sstream>
#include <string.h>
#ifdef __linux__
#include <sys/socket.h>
#include <unistd.h>
#elif _WIN32 || defined(__CYGWIN__)
#include <windows.h>
#endif
static void encode_base64(char dest[4], const uint8_t src[3]) {
const uint8_t input[] = {
static_cast<uint8_t>((src[0] >> 2) & 63),
static_cast<uint8_t>(((src[0] << 4) | (src[1] >> 4)) & 63),
static_cast<uint8_t>(((src[1] << 2) | (src[2] >> 6)) & 63),
static_cast<uint8_t>(src[2] & 63)};
unsigned int i;
for (i = 0; i < 4; ++i)
dest[i] = input[i] + 'A' + (((25 - input[i]) >> 8) & 6) -
(((51 - input[i]) >> 8) & 75) - (((61 - input[i]) >> 8) & 15) +
(((62 - input[i]) >> 8) & 3);
}
void keyToBase64(wg_key_b64_string base64, const wg_key key) {
unsigned int i;
for (i = 0; i < 32 / 3; ++i)
encode_base64(&base64[i * 4], &key[i * 3]);
const uint8_t tempKey[3] = {key[i * 3 + 0], key[i * 3 + 1], 0};
encode_base64(&base64[i * 4], tempKey);
base64[sizeof(wg_key_b64_string) - 2] = '=';
base64[sizeof(wg_key_b64_string) - 1] = '\0';
}
static int decodeBase64(const char src[4]) {
int val = 0;
unsigned int i;
for (i = 0; i < 4; ++i)
val |=
(-1 +
((((('A' - 1) - src[i]) & (src[i] - ('Z' + 1))) >> 8) &
(src[i] - 64)) +
((((('a' - 1) - src[i]) & (src[i] - ('z' + 1))) >> 8) &
(src[i] - 70)) +
((((('0' - 1) - src[i]) & (src[i] - ('9' + 1))) >> 8) & (src[i] + 5)) +
((((('+' - 1) - src[i]) & (src[i] - ('+' + 1))) >> 8) & 63) +
((((('/' - 1) - src[i]) & (src[i] - ('/' + 1))) >> 8) & 64))
<< (18 - 6 * i);
return val;
}
#ifdef _WIN32
static volatile void *(*memset_func)(void *, int, size_t) =
(volatile void *(*)(void *, int, size_t)) & memset;
void memzero_explicit(void *s, size_t count) { memset_func(s, 0, count); }
#else
static __attribute__((noinline)) void memzero_explicit(void *s, size_t count) {
memset(s, 0, count);
__asm__ __volatile__("" : : "r"(s) : "memory");
}
#endif
static void carry(fe o) {
int i;
for (i = 0; i < 16; ++i) {
o[(i + 1) % 16] += (i == 15 ? 38 : 1) * (o[i] >> 16);
o[i] &= 0xffff;
}
}
static void cswap(fe p, fe q, int b) {
int i;
int64_t t, c = ~(b - 1);
for (i = 0; i < 16; ++i) {
t = c & (p[i] ^ q[i]);
p[i] ^= t;
q[i] ^= t;
}
memzero_explicit(&t, sizeof(t));
memzero_explicit(&c, sizeof(c));
memzero_explicit(&b, sizeof(b));
}
static void pack(uint8_t *o, const fe n) {
int i, j, b;
fe m, t;
memcpy(t, n, sizeof(t));
carry(t);
carry(t);
carry(t);
for (j = 0; j < 2; ++j) {
m[0] = t[0] - 0xffed;
for (i = 1; i < 15; ++i) {
m[i] = t[i] - 0xffff - ((m[i - 1] >> 16) & 1);
m[i - 1] &= 0xffff;
}
m[15] = t[15] - 0x7fff - ((m[14] >> 16) & 1);
b = (m[15] >> 16) & 1;
m[14] &= 0xffff;
cswap(t, m, 1 - b);
}
for (i = 0; i < 16; ++i) {
o[2 * i] = t[i] & 0xff;
o[2 * i + 1] = t[i] >> 8;
}
memzero_explicit(m, sizeof(m));
memzero_explicit(t, sizeof(t));
memzero_explicit(&b, sizeof(b));
}
static void add(fe o, const fe a, const fe b) {
int i;
for (i = 0; i < 16; ++i)
o[i] = a[i] + b[i];
}
static void subtract(fe o, const fe a, const fe b) {
int i;
for (i = 0; i < 16; ++i)
o[i] = a[i] - b[i];
}
static void multmod(fe o, const fe a, const fe b) {
int i, j;
int64_t t[31] = {0};
for (i = 0; i < 16; ++i) {
for (j = 0; j < 16; ++j)
t[i + j] += a[i] * b[j];
}
for (i = 0; i < 15; ++i)
t[i] += 38 * t[i + 16];
memcpy(o, t, sizeof(fe));
carry(o);
carry(o);
memzero_explicit(t, sizeof(t));
}
static void invert(fe o, const fe i) {
fe c;
int a;
memcpy(c, i, sizeof(c));
for (a = 253; a >= 0; --a) {
multmod(c, c, c);
if (a != 2 && a != 4)
multmod(c, c, i);
}
memcpy(o, c, sizeof(fe));
memzero_explicit(c, sizeof(c));
}
void wgKeys::generatePreshared(wg_key preshared_key) {
#if _WIN32 || defined(__CYGWIN__)
HCRYPTPROV hCryptProv;
BOOL winStatus;
if ((winStatus = CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT)))
winStatus =
CryptGenRandom(hCryptProv, sizeof(wg_key), (BYTE *)preshared_key);
CryptReleaseContext(hCryptProv, 0);
if (winStatus)
return;
#elif defined(__OpenBSD__) || \
(defined(__APPLE__) && \
MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_12) || \
(defined(__GLIBC__) && \
(__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 25)))
if (!getentropy(preshared_key, sizeof(wg_key)))
return;
#elif defined(__NR_getrandom) && defined(__linux__)
if (syscall(__NR_getrandom, preshared_key, sizeof(wg_key), 0) ==
sizeof(wg_key))
return;
#elif __linux__ || _ANDROID__ || __termux__
size_t ret, i;
int fd;
fd = open("/dev/urandom", O_RDONLY);
if (fd <= 0);
for (i = 0; i < sizeof(wg_key); i += ret) {
ret = read(fd, preshared_key + i, sizeof(wg_key) - i);
if (ret < 0);
}
close(fd);
return;
#endif
std::random_device rd;
for (uint8_t i = 0; i < sizeof(wg_key); ++i) {
std::mt19937 mt(rd());
std::uniform_int_distribution<int> dist(1, 429496729);
preshared_key[i] = dist(mt) * rand();
}
return;
}
static void clamp_key(uint8_t *z) {
z[31] = (z[31] & 127) | 64;
z[0] &= 248;
}
void wgKeys::generatePrivate(wg_key private_key) {
wgKeys::generatePreshared(private_key);
clamp_key(private_key);
}
void wgKeys::generatePublic(wg_key public_key, const wg_key private_key) {
int i, r;
uint8_t z[32];
fe a = {1}, b = {9}, c = {0}, d = {1}, e, f;
memcpy(z, private_key, sizeof(z));
clamp_key(z);
for (i = 254; i >= 0; --i) {
r = (z[i >> 3] >> (i & 7)) & 1;
cswap(a, b, r);
cswap(c, d, r);
add(e, a, c);
subtract(a, a, c);
add(c, b, d);
subtract(b, b, d);
multmod(d, e, e);
multmod(f, a, a);
multmod(a, c, a);
multmod(c, b, e);
add(e, a, c);
subtract(a, a, c);
multmod(b, a, a);
subtract(c, d, f);
const fe abc = {0xdb41, 1};
multmod(a, c, abc);
add(a, a, d);
multmod(c, c, a);
multmod(a, d, f);
const fe abc2 = {9};
multmod(d, b, abc2);
multmod(b, e, e);
cswap(a, b, r);
cswap(c, d, r);
}
invert(c, c);
multmod(a, a, c);
pack(public_key, a);
memzero_explicit(&r, sizeof(r));
memzero_explicit(z, sizeof(z));
memzero_explicit(a, sizeof(a));
memzero_explicit(b, sizeof(b));
memzero_explicit(c, sizeof(c));
memzero_explicit(d, sizeof(d));
memzero_explicit(e, sizeof(e));
memzero_explicit(f, sizeof(f));
}
std::string wgKeys::generatePublic(const std::string &private_key) {
wg_key public_key;
wg_key private_key_;
stringToKey(private_key_, private_key);
generatePublic(public_key, private_key_);
return toString(public_key);
}
bool key_is_zero(const uint8_t key[32]) {
volatile uint8_t acc = 0;
for (unsigned int i = 0; i < 32; ++i) {
acc |= key[i];
// asm volatile("" : "=r"(acc) : "0"(acc));
}
return !!(1 & ((acc - 1) >> 8));
}
void wgKeys::stringToKey(wg_key key, std::string keyBase64) {
const char* base64 = keyBase64.c_str();
if (keyBase64.length() != B64_WG_KEY_LENGTH ||
base64[B64_WG_KEY_LENGTH - 1] != '=')
throw std::string("invalid key, length: ")
.append(std::to_string(keyBase64.length()));
unsigned int i;
int val;
volatile uint8_t ret = 0;
for (i = 0; i < 32 / 3; ++i) {
val = decodeBase64(&base64[i * 4]);
ret |= (uint32_t)val >> 31;
key[i * 3 + 0] = (val >> 16) & 0xff;
key[i * 3 + 1] = (val >> 8) & 0xff;
key[i * 3 + 2] = val & 0xff;
}
const char tempDecode[4] = {base64[i * 4 + 0], base64[i * 4 + 1],
base64[i * 4 + 2], 'A'};
val = decodeBase64(tempDecode);
ret |= ((uint32_t)val >> 31) | (val & 0xff);
key[i * 3 + 0] = (val >> 16) & 0xff;
key[i * 3 + 1] = (val >> 8) & 0xff;
int status = EINVAL & ~((ret - 1) >> 8);
if (status != 0)
throw std::string("Cannot decode key, ret code: ")
.append(std::to_string(status));
}
std::string wgKeys::toString(const wg_key key) {
wg_key_b64_string base64;
unsigned int i;
for (i = 0; i < 32 / 3; ++i) encode_base64(&base64[i * 4], &key[i * 3]);
const uint8_t tempKey[3] = {key[i * 3 + 0], key[i * 3 + 1], 0};
encode_base64(&base64[i * 4], tempKey);
base64[sizeof(wg_key_b64_string) - 2] = '=';
base64[sizeof(wg_key_b64_string) - 1] = '\0';
return std::string(base64);
}
std::string wgKeys::toHex(const std::string &keyBase64) {
wg_key key;
wgKeys::stringToKey(key, keyBase64);
char hex[65];
for (int i = 0; i < 32; ++i) sprintf(hex + i * 2, "%02x", key[i]);
hex[64] = '\0';
return std::string(hex);
}
std::string wgKeys::HextoBase64(const std::string &s_hex) {
wg_key key;
for(unsigned i = 0, uchr ; i < s_hex.length() ; i += 2) {
sscanf( s_hex.c_str()+ i, "%2x", &uchr); // conversion
key[i/2] = uchr; // save as char
}
return wgKeys::toString(key);
}