From 3b08df649e2337594f398e7f47b7baea8188ed96 Mon Sep 17 00:00:00 2001 From: mame Date: Mon, 11 Sep 2017 12:44:51 +0000 Subject: lib/securerandom.rb: test one byte to determine urandom or openssl `SecureRandom#gen_random` determines whether urandom is available or not by trying `Random.urandom(n)`. But, when n = 0, `Random.urandom(0)` always succeeds even if urandom is not available, which leads to a wrong decision. When failed, `Random.urandom` returns nil instead of returning a shorter string than required. So the check for `ret.length != n` is not needed. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59840 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- lib/securerandom.rb | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/lib/securerandom.rb b/lib/securerandom.rb index dc7584a277..2140a7e1fc 100644 --- a/lib/securerandom.rb +++ b/lib/securerandom.rb @@ -52,7 +52,7 @@ module SecureRandom end def gen_random(n) - ret = Random.urandom(n) + ret = Random.urandom(1) if ret.nil? begin require 'openssl' @@ -67,10 +67,6 @@ module SecureRandom end return gen_random(n) end - elsif ret.length != n - raise NotImplementedError, \ - "Unexpected partial read from random device: " \ - "only #{ret.length} for #{n} bytes" else @rng_chooser.synchronize do class << self -- cgit v1.2.3