mirror of
https://github.com/janet-lang/janet
synced 2024-12-25 07:50:27 +00:00
Address Issue #184.
Fix strtod.c with better range checking to prevent DOS.
This commit is contained in:
parent
967a8b5a70
commit
688d297a18
@ -196,7 +196,7 @@ static double bignat_extract(struct BigNat *mant, int32_t exponent2) {
|
||||
|
||||
/* Read in a mantissa and exponent of a certain base, and give
|
||||
* back the double value. Should properly handle 0s, infinities, and
|
||||
* denormalized numbers. (When the exponent values are too large) */
|
||||
* denormalized numbers. (When the exponent values are too large or small) */
|
||||
static double convert(
|
||||
int negative,
|
||||
struct BigNat *mant,
|
||||
@ -205,11 +205,20 @@ static double convert(
|
||||
|
||||
int32_t exponent2 = 0;
|
||||
|
||||
/* Short circuit zero and huge numbers */
|
||||
/* Approximate exponent in base 2 of mant and exponent. This should get us a good estimate of the final size of the
|
||||
* number, within * 2^32 or so. */
|
||||
int32_t mant_exp2_approx = mant->n * 32 + 16;
|
||||
int32_t exp_exp2_approx = (int32_t)(floor(log2(base) * exponent));
|
||||
int32_t exp2_approx = mant_exp2_approx + exp_exp2_approx;
|
||||
|
||||
/* Short circuit zero, huge, and small numbers. We use the exponent range of valid IEEE754 doubles (-1022, 1023)
|
||||
* with a healthy buffer to allow for inaccuracies in the approximation and denormailzed numbers. */
|
||||
if (mant->n == 0 && mant->first_digit == 0)
|
||||
return negative ? -0.0 : 0.0;
|
||||
if (exponent > 1023)
|
||||
if (exp2_approx > 1176)
|
||||
return negative ? -INFINITY : INFINITY;
|
||||
if (exp2_approx < -1175)
|
||||
return negative ? -0.0 : 0.0;
|
||||
|
||||
/* Final value is X = mant * base ^ exponent * 2 ^ exponent2
|
||||
* Get exponent to zero while holding X constant. */
|
||||
@ -326,7 +335,7 @@ int janet_scan_number(
|
||||
/* Read exponent */
|
||||
if (str < end && foundexp) {
|
||||
int eneg = 0;
|
||||
int ee = 0;
|
||||
int32_t ee = 0;
|
||||
seenadigit = 0;
|
||||
str++;
|
||||
if (str >= end) goto error;
|
||||
@ -341,10 +350,12 @@ int janet_scan_number(
|
||||
str++;
|
||||
seenadigit = 1;
|
||||
}
|
||||
while (str < end && ee < (INT32_MAX / 40)) {
|
||||
while (str < end) {
|
||||
int digit = digit_lookup[*str & 0x7F];
|
||||
if (*str > 127 || digit >= base) goto error;
|
||||
ee = base * ee + digit;
|
||||
if (ee < (INT32_MAX / 40)) {
|
||||
ee = base * ee + digit;
|
||||
}
|
||||
str++;
|
||||
seenadigit = 1;
|
||||
}
|
||||
|
@ -235,4 +235,7 @@
|
||||
(def environ (os/environ))
|
||||
(assert (= [(environ "TESTENV1") (environ "TESTENV2")] ["v1" "v2"]) "environ works")
|
||||
|
||||
# Issue #183 - just parse it :)
|
||||
1e-4000000000000000000000
|
||||
|
||||
(end-suite)
|
||||
|
Loading…
Reference in New Issue
Block a user