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Extract random number generator from websocket client code

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This commit is contained in:
bel2125
2015-12-08 10:39:15 +01:00
parent 8e536227a4
commit ca3b2c14db
1 changed files with 31 additions and 21 deletions
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52
src/civetweb.c
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@@ -1571,6 +1571,33 @@ mg_snprintf(const struct mg_connection *conn,
va_end(ap);
}
static int64_t
get_random(void)
{
static uint64_t lfsr = 0;
static uint64_t lcg = 0;
struct timespec now;
memset(&now, 0, sizeof(now));
clock_gettime(CLOCK_MONOTONIC, &now);
if (lfsr == 0) {
lfsr = (((uint64_t)now.tv_sec) << 21) ^ (uint64_t)now.tv_nsec
^ (uint64_t)(ptrdiff_t)&now;
lcg = (((uint64_t)now.tv_sec) << 25) + (uint64_t)now.tv_nsec
+ (uint64_t)(ptrdiff_t)&now;
} else {
lfsr = (lfsr >> 1)
| ((((lfsr >> 0) ^ (lfsr >> 1) ^ (lfsr >> 3) ^ (lfsr >> 4)) & 1)
<< 63);
lcg = lcg * 6364136223846793005 + 1442695040888963407;
}
return (lfsr ^ lcg ^ now.tv_nsec);
}
static int
get_option_index(const char *name)
{
@@ -8262,27 +8289,7 @@ mg_websocket_client_write(struct mg_connection *conn,
{
int retval = -1;
char *masked_data = (char *)mg_malloc(((dataLen + 7) / 4) * 4);
uint32_t masking_key;
static uint64_t lfsr = 0;
static uint64_t lcg = 0;
struct timespec now;
memset(&now, 0, sizeof(now));
clock_gettime(CLOCK_MONOTONIC, &now);
if (lfsr == 0) {
lfsr = (((uint64_t)now.tv_sec) << 21) ^ (uint64_t)now.tv_nsec
^ (uint64_t)&dataLen;
lcg = (((uint64_t)now.tv_sec) << 25) + (uint64_t)now.tv_nsec
+ (uint64_t)data;
} else {
lfsr = (lfsr >> 1)
| ((((lfsr >> 0) ^ (lfsr >> 1) ^ (lfsr >> 3) ^ (lfsr >> 4)) & 1)
<< 63);
lcg = lcg * 6364136223846793005 + 1442695040888963407;
}
masking_key = (uint32_t)lfsr ^ (uint32_t)lcg ^ (uint32_t)now.tv_nsec;
uint32_t masking_key = (uint32_t)get_random();
if (masked_data == NULL) {
/* Return -1 in an error case */
@@ -11852,6 +11859,9 @@ mg_start(const struct mg_callbacks *callbacks,
return NULL;
}
/* Random number generator will initialize at the first call */
(void)get_random();
if (mg_atomic_inc(&sTlsInit) == 1) {
#if defined(_WIN32) && !defined(__SYMBIAN32__)