cipher: validate iterations argument for Cipher#pkcs5_keyivgenky/cipher-pkcs5-keyivgen-validate-iter

EVP_BytesToKey() internally converts the iteration count given as an
"int" into an "unsigned int". Calling that with a negative integer will
result in a hang. This is surprising, so let's validate the value by
ourselves and raise ArgumentError as necessary.

1 files changed, 3 insertions, 0 deletions

diff --git a/test/test_cipher.rb b/test/test_cipher.rb
index 48149d41..732b4fdd 100644
--- a/test/test_cipher.rb
+++ b/test/test_cipher.rb
@@ -44,6 +44,9 @@ class OpenSSL::TestCipher < OpenSSL::TestCase
     s2 = cipher.update(pt) << cipher.final
 
     assert_equal s1, s2
+
+    cipher2 = OpenSSL::Cipher.new("DES-EDE3-CBC").encrypt
+    assert_raise(ArgumentError) { cipher2.pkcs5_keyivgen(pass, salt, -1, "MD5") }
   end
 
   def test_info