random: add OpenSSL::Random.pollky/rand-poll

As a direct wrapper of RAND_poll() which seeds OpenSSL's CSPRNG using a
system-provided entropy source.

1 files changed, 19 insertions, 0 deletions

diff --git a/ext/openssl/ossl_rand.c b/ext/openssl/ossl_rand.c
index 688c525a..b9b2ba97 100644
--- a/ext/openssl/ossl_rand.c
+++ b/ext/openssl/ossl_rand.c
@@ -60,6 +60,24 @@ ossl_rand_add(VALUE self, VALUE str, VALUE entropy)
 
 /*
  *  call-seq:
+ *     poll -> self
+ *
+ * Seeds the random number generator using a system-provided entropy source.
+ *
+ * This is automatically called through OpenSSL::Random.random_bytes on the
+ * first call, but manual reseeding is required after forking.
+ */
+static VALUE
+ossl_rand_poll(VALUE self)
+{
+    if (!RAND_poll())
+	ossl_raise(eRandomError, "RAND_poll");
+
+    return self;
+}
+
+/*
+ *  call-seq:
  *     load_random_file(filename) -> true
  *
  * Reads bytes from +filename+ and adds them to the PRNG.
@@ -224,6 +242,7 @@ Init_ossl_rand(void)
 
     rb_define_module_function(mRandom, "seed", ossl_rand_seed, 1);
     rb_define_module_function(mRandom, "random_add", ossl_rand_add, 2);
+    rb_define_module_function(mRandom, "poll", ossl_rand_poll, 0);
     rb_define_module_function(mRandom, "load_random_file", ossl_rand_load_file, 1);
     rb_define_module_function(mRandom, "write_random_file", ossl_rand_write_file, 1);
     rb_define_module_function(mRandom, "random_bytes", ossl_rand_bytes, 1);