revert low rounds-count limits in crypt hashes

it was determined in discussion that these kind of limits are not
sufficient to protect single-threaded servers against denial of
service attacks from maliciously large round counts. the time scales
simply vary too much; many users will want login passwords with rounds
counts on a scale that gives decisecond latency, while highly loaded
webservers will need millisecond latency or shorter.

still some limit is left in place; the idea is not to protect against
attacks, but to avoid the runtime of a single call to crypt being, for
all practical purposes, infinite, so that configuration errors can be
caught and fixed without bringing down whole systems. these limits are
very high, on the order of minute-long runtimes for modest systems.
This commit is contained in:
Rich Felker
2012-09-15 03:03:21 -04:00
parent 881868382a
commit aeaceb1fa8
4 changed files with 4 additions and 4 deletions
+1 -1
View File
@@ -911,7 +911,7 @@ static char *_crypt_extended_r_uut(const char *_key, const char *_setting, char
return NULL;
count |= value << (i - 1) * 6;
}
if (!count || count > 262143)
if (!count)
return NULL;
for (i = 5, salt = 0; i < 9; i++) {