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authorshyouhei <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2017-01-20 08:00:00 (GMT)
committershyouhei <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2017-01-20 08:00:00 (GMT)
commitabae70d6ed63054d7d01bd6cd80c1b5b98b93ba3 (patch)
tree3de590fcf8f22217987675fbc5eea399597c8fca /random.c
parente95eb9584ac85b728734d77e07fa27f23c91f38d (diff)
SecureRandom should try /dev/urandom first [Bug #9569]
* random.c (InitVM_Random): rename Random.raw_seed to Random.urandom. A quick search seems there are no practical use of this method than securerandom.rb so I think it's OK to rename but if there are users of it, this hunk is subject to revert. * test/ruby/test_rand.rb (TestRand#test_urandom): test for it. * lib/securerandom.rb (SecureRandom.gen_random): Prefer OS- provided CSPRNG if available. Otherwise falls back to OpenSSL. Current preference is: 1. CSPRNG routine that the OS has; one of - getrandom(2), - arc4random(3), or - CryptGenRandom() 2. /dev/urandom device 3. OpenSSL's RAND_bytes(3) If none of above random number generators are available, you cannot use this module. An exception is raised that case. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57384 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'random.c')
-rw-r--r--random.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/random.c b/random.c
index ddbbeed..6555cc5 100644
--- a/random.c
+++ b/random.c
@@ -603,11 +603,18 @@ random_seed(void)
}
/*
- * call-seq: Random.raw_seed(size) -> string
+ * call-seq: Random.urandom(size) -> string
*
- * Returns a raw seed string, using platform providing features.
+ * Returns a string, using platform providing features.
+ * Returned value expected to be a cryptographically secure
+ * pseudo-random number in binary form.
*
- * Random.raw_seed(8) #=> "\x78\x41\xBA\xAF\x7D\xEA\xD8\xEA"
+ * In 2017, Linux manpage random(7) writes that "no cryptographic
+ * primitive available today can hope to promise more than 256 bits of
+ * security". So it might be questionable to pass size > 32 to this
+ * method.
+ *
+ * Random.urandom(8) #=> "\x78\x41\xBA\xAF\x7D\xEA\xD8\xEA"
*/
static VALUE
random_raw_seed(VALUE self, VALUE size)
@@ -1616,7 +1623,7 @@ InitVM_Random(void)
rb_define_singleton_method(rb_cRandom, "srand", rb_f_srand, -1);
rb_define_singleton_method(rb_cRandom, "rand", random_s_rand, -1);
rb_define_singleton_method(rb_cRandom, "new_seed", random_seed, 0);
- rb_define_singleton_method(rb_cRandom, "raw_seed", random_raw_seed, 1);
+ rb_define_singleton_method(rb_cRandom, "urandom", random_raw_seed, 1);
rb_define_private_method(CLASS_OF(rb_cRandom), "state", random_s_state, 0);
rb_define_private_method(CLASS_OF(rb_cRandom), "left", random_s_left, 0);