openssl: clear OpenSSL error queue before return to Ruby

* ext/openssl/ossl_x509cert.c (ossl_x509_verify): X509_verify()
  family may put errors on 0 return (0 means verification failure).
  Clear OpenSSL error queue before return to Ruby. Since the queue is
  thread global, remaining errors in the queue can cause an unexpected
  error in the next OpenSSL operation.  [ruby-core:48284] [Bug #7215]

* ext/openssl/ossl_x509crl.c (ossl_x509crl_verify): ditto.

* ext/openssl/ossl_x509req.c (ossl_x509req_verify): ditto.

* ext/openssl/ossl_x509store.c (ossl_x509stctx_verify): ditto.

* ext/openssl/ossl_pkey_dh.c (dh_generate): clear the OpenSSL error
  queue before re-raising exception.

* ext/openssl/ossl_pkey_dsa.c (dsa_generate): ditto.

* ext/openssl/ossl_pkey_rsa.c (rsa_generate): ditto.

* ext/openssl/ossl_ssl.c (ossl_start_ssl): ditto.

* test/openssl: check that OpenSSL.errors is empty every time after
  running a test case.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55051 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

35 files changed, 99 insertions, 108 deletions

diff --git a/ext/openssl/ossl_pkey_dh.c b/ext/openssl/ossl_pkey_dh.c
index 2f79bfb2..19c517fd 100644
--- a/ext/openssl/ossl_pkey_dh.c
+++ b/ext/openssl/ossl_pkey_dh.c
@@ -129,7 +129,11 @@ dh_generate(int size, int gen)
 
     if (!gen_arg.result) {
 	DH_free(dh);
-	if (cb_arg.state) rb_jump_tag(cb_arg.state);
+	if (cb_arg.state) {
+	    /* Clear OpenSSL error queue before re-raising. */
+	    ossl_clear_error();
+	    rb_jump_tag(cb_arg.state);
+	}
 	return 0;
     }
 #else
diff --git a/ext/openssl/ossl_pkey_dsa.c b/ext/openssl/ossl_pkey_dsa.c
index 2e42a0ce..4c0c3f1b 100644
--- a/ext/openssl/ossl_pkey_dsa.c
+++ b/ext/openssl/ossl_pkey_dsa.c
@@ -135,7 +135,14 @@ dsa_generate(int size)
     }
     if (!gen_arg.result) {
 	DSA_free(dsa);
-	if (cb_arg.state) rb_jump_tag(cb_arg.state);
+	if (cb_arg.state) {
+	    /* Clear OpenSSL error queue before re-raising. By the way, the
+	     * documentation of DSA_generate_parameters_ex() says the error code
+	     * can be obtained by ERR_get_error(), but the default
+	     * implementation, dsa_builtin_paramgen() doesn't put any error... */
+	    ossl_clear_error();
+	    rb_jump_tag(cb_arg.state);
+	}
 	return 0;
     }
 #else
diff --git a/ext/openssl/ossl_pkey_rsa.c b/ext/openssl/ossl_pkey_rsa.c
index 20b993ab..6ad9f3ed 100644
--- a/ext/openssl/ossl_pkey_rsa.c
+++ b/ext/openssl/ossl_pkey_rsa.c
@@ -139,7 +139,11 @@ rsa_generate(int size, unsigned long exp)
     if (!gen_arg.result) {
 	BN_free(e);
 	RSA_free(rsa);
-	if (cb_arg.state) rb_jump_tag(cb_arg.state);
+	if (cb_arg.state) {
+	    /* must clear OpenSSL error stack */
+	    ossl_clear_error();
+	    rb_jump_tag(cb_arg.state);
+	}
 	return 0;
     }
 
diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c
index 10797109..938e36f1 100644
--- a/ext/openssl/ossl_ssl.c
+++ b/ext/openssl/ossl_ssl.c
@@ -1288,8 +1288,11 @@ ossl_start_ssl(VALUE self, int (*func)(), const char *funcname, VALUE opts)
 	ret = func(ssl);
 
         cb_state = rb_ivar_get(self, ID_callback_state);
-        if (!NIL_P(cb_state))
-            rb_jump_tag(NUM2INT(cb_state));
+        if (!NIL_P(cb_state)) {
+	    /* must cleanup OpenSSL error stack before re-raising */
+	    ossl_clear_error();
+	    rb_jump_tag(NUM2INT(cb_state));
+	}
 
 	if (ret > 0)
 	    break;
diff --git a/ext/openssl/ossl_x509cert.c b/ext/openssl/ossl_x509cert.c
index 4dafae17..226704ef 100644
--- a/ext/openssl/ossl_x509cert.c
+++ b/ext/openssl/ossl_x509cert.c
@@ -591,18 +591,19 @@ ossl_x509_verify(VALUE self, VALUE key)
 {
     X509 *x509;
     EVP_PKEY *pkey;
-    int i;
 
     pkey = GetPKeyPtr(key); /* NO NEED TO DUP */
     GetX509(self, x509);
-    if ((i = X509_verify(x509, pkey)) < 0) {
-	ossl_raise(eX509CertError, NULL);
-    }
-    if (i > 0) {
+
+    switch (X509_verify(x509, pkey)) {
+      case 1:
 	return Qtrue;
+      case 0:
+	ossl_clear_error();
+	return Qfalse;
+      default:
+	ossl_raise(eX509CertError, NULL);
     }
-
-    return Qfalse;
 }
 
 /*
diff --git a/ext/openssl/ossl_x509crl.c b/ext/openssl/ossl_x509crl.c
index f64712ef..a660ccce 100644
--- a/ext/openssl/ossl_x509crl.c
+++ b/ext/openssl/ossl_x509crl.c
@@ -360,17 +360,17 @@ static VALUE
 ossl_x509crl_verify(VALUE self, VALUE key)
 {
     X509_CRL *crl;
-    int ret;
 
     GetX509CRL(self, crl);
-    if ((ret = X509_CRL_verify(crl, GetPKeyPtr(key))) < 0) {
-	ossl_raise(eX509CRLError, NULL);
-    }
-    if (ret == 1) {
+    switch (X509_CRL_verify(crl, GetPKeyPtr(key))) {
+      case 1:
 	return Qtrue;
+      case 0:
+	ossl_clear_error();
+	return Qfalse;
+      default:
+	ossl_raise(eX509CRLError, NULL);
     }
-
-    return Qfalse;
 }
 
 static VALUE
diff --git a/ext/openssl/ossl_x509req.c b/ext/openssl/ossl_x509req.c
index e5ce088a..c1cdca5f 100644
--- a/ext/openssl/ossl_x509req.c
+++ b/ext/openssl/ossl_x509req.c
@@ -375,18 +375,18 @@ ossl_x509req_verify(VALUE self, VALUE key)
 {
     X509_REQ *req;
     EVP_PKEY *pkey;
-    int i;
 
     GetX509Req(self, req);
     pkey = GetPKeyPtr(key); /* NO NEED TO DUP */
-    if ((i = X509_REQ_verify(req, pkey)) < 0) {
-	ossl_raise(eX509ReqError, NULL);
-    }
-    if (i > 0) {
+    switch (X509_REQ_verify(req, pkey)) {
+      case 1:
 	return Qtrue;
+      case 0:
+	ossl_clear_error();
+	return Qfalse;
+      default:
+	ossl_raise(eX509ReqError, NULL);
     }
-
-    return Qfalse;
 }
 
 static VALUE
diff --git a/ext/openssl/ossl_x509store.c b/ext/openssl/ossl_x509store.c
index bb6fe14d..aca25b15 100644
--- a/ext/openssl/ossl_x509store.c
+++ b/ext/openssl/ossl_x509store.c
@@ -464,14 +464,20 @@ static VALUE
 ossl_x509stctx_verify(VALUE self)
 {
     X509_STORE_CTX *ctx;
-    int result;
 
     GetX509StCtx(self, ctx);
     X509_STORE_CTX_set_ex_data(ctx, ossl_verify_cb_idx,
-                               (void*)rb_iv_get(self, "@verify_callback"));
-    result = X509_verify_cert(ctx);
-
-    return result ? Qtrue : Qfalse;
+			       (void *)rb_iv_get(self, "@verify_callback"));
+
+    switch (X509_verify_cert(ctx)) {
+      case 1:
+	return Qtrue;
+      case 0:
+	ossl_clear_error();
+	return Qfalse;
+      default:
+	ossl_raise(eX509CertError, NULL);
+    }
 }
 
 static VALUE
diff --git a/test/test_asn1.rb b/test/test_asn1.rb
index fd2118d8..9db9ec51 100644
--- a/test/test_asn1.rb
+++ b/test/test_asn1.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: false
 require_relative 'utils'
 
-class  OpenSSL::TestASN1 < Test::Unit::TestCase
+class  OpenSSL::TestASN1 < OpenSSL::TestCase
   def test_decode
     subj = OpenSSL::X509::Name.parse("/DC=org/DC=ruby-lang/CN=TestCA")
     key = OpenSSL::TestUtils::TEST_KEY_RSA1024
diff --git a/test/test_bn.rb b/test/test_bn.rb
index 415bd74c..37ba5e55 100644
--- a/test/test_bn.rb
+++ b/test/test_bn.rb
@@ -3,7 +3,7 @@ require_relative 'utils'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestBN < Test::Unit::TestCase
+class OpenSSL::TestBN < OpenSSL::TestCase
   def test_new_str
     e1 = OpenSSL::BN.new(999.to_s(16), 16) # OpenSSL::BN.new(str, 16) must be most stable
     e2 = OpenSSL::BN.new((2**107-1).to_s(16), 16)
diff --git a/test/test_buffering.rb b/test/test_buffering.rb
index 1f552c93..1f42cd3c 100644
--- a/test/test_buffering.rb
+++ b/test/test_buffering.rb
@@ -2,7 +2,7 @@
 require_relative 'utils'
 require 'stringio'
 
-class OpenSSL::TestBuffering < Test::Unit::TestCase
+class OpenSSL::TestBuffering < OpenSSL::TestCase
 
   class IO
     include OpenSSL::Buffering
diff --git a/test/test_cipher.rb b/test/test_cipher.rb
index 32f0d118..dab64aa5 100644
--- a/test/test_cipher.rb
+++ b/test/test_cipher.rb
@@ -3,7 +3,7 @@ require_relative 'utils'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestCipher < Test::Unit::TestCase
+class OpenSSL::TestCipher < OpenSSL::TestCase
 
   class << self
 
@@ -34,6 +34,7 @@ class OpenSSL::TestCipher < Test::Unit::TestCase
   end
 
   def teardown
+    super
     @c1 = @c2 = nil
   end
 
diff --git a/test/test_config.rb b/test/test_config.rb
index 812b28b9..3e2e1273 100644
--- a/test/test_config.rb
+++ b/test/test_config.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: false
 require_relative 'utils'
 
-class OpenSSL::TestConfig < Test::Unit::TestCase
+class OpenSSL::TestConfig < OpenSSL::TestCase
   def setup
     file = Tempfile.open("openssl.cnf")
     file << <<__EOD__
@@ -18,6 +18,7 @@ __EOD__
   end
 
   def teardown
+    super
     @tmpfile.close!
   end
 
diff --git a/test/test_digest.rb b/test/test_digest.rb
index 8b724a03..ba3e974b 100644
--- a/test/test_digest.rb
+++ b/test/test_digest.rb
@@ -3,7 +3,7 @@ require_relative 'utils'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestDigest < Test::Unit::TestCase
+class OpenSSL::TestDigest < OpenSSL::TestCase
   def setup
     @d1 = OpenSSL::Digest.new("MD5")
     @d2 = OpenSSL::Digest::MD5.new
@@ -12,6 +12,7 @@ class OpenSSL::TestDigest < Test::Unit::TestCase
   end
 
   def teardown
+    super
     @d1 = @d2 = @md = nil
   end
 
diff --git a/test/test_engine.rb b/test/test_engine.rb
index 3521de63..9a0da340 100644
--- a/test/test_engine.rb
+++ b/test/test_engine.rb
@@ -1,9 +1,10 @@
 # frozen_string_literal: false
 require_relative 'utils'
 
-class OpenSSL::TestEngine < Test::Unit::TestCase
+class OpenSSL::TestEngine < OpenSSL::TestCase
 
   def teardown
+    super
     OpenSSL::Engine.cleanup # [ruby-core:40669]
     assert_equal(0, OpenSSL::Engine.engines.size)
   end
diff --git a/test/test_fips.rb b/test/test_fips.rb
index 33769c93..534dade0 100644
--- a/test/test_fips.rb
+++ b/test/test_fips.rb
@@ -3,7 +3,7 @@ require_relative 'utils'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestFIPS < Test::Unit::TestCase
+class OpenSSL::TestFIPS < OpenSSL::TestCase
 
   def test_fips_mode_is_reentrant
     OpenSSL.fips_mode = false
diff --git a/test/test_hmac.rb b/test/test_hmac.rb
index 135d26f0..3c90a5de 100644
--- a/test/test_hmac.rb
+++ b/test/test_hmac.rb
@@ -3,7 +3,7 @@
 
 require_relative 'utils'
 
-class OpenSSL::TestHMAC < Test::Unit::TestCase
+class OpenSSL::TestHMAC < OpenSSL::TestCase
   def setup
     @digest = OpenSSL::Digest::MD5
     @key = "KEY"
@@ -12,9 +12,6 @@ class OpenSSL::TestHMAC < Test::Unit::TestCase
     @h2 = OpenSSL::HMAC.new(@key, "MD5")
   end
 
-  def teardown
-  end
-
   def test_hmac
     @h1.update(@data)
     @h2.update(@data)
diff --git a/test/test_ns_spki.rb b/test/test_ns_spki.rb
index 4f6e6f59..4740c0b2 100644
--- a/test/test_ns_spki.rb
+++ b/test/test_ns_spki.rb
@@ -3,7 +3,7 @@ require_relative 'utils'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestNSSPI < Test::Unit::TestCase
+class OpenSSL::TestNSSPI < OpenSSL::TestCase
   def setup
     # This request data is adopt from the specification of
     # "Netscape Extensions for User Key Generation".
diff --git a/test/test_ocsp.rb b/test/test_ocsp.rb
index 1a969fd7..d04b4216 100644
--- a/test/test_ocsp.rb
+++ b/test/test_ocsp.rb
@@ -3,7 +3,7 @@ require_relative "utils"
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestOCSP < Test::Unit::TestCase
+class OpenSSL::TestOCSP < OpenSSL::TestCase
   def setup
     ca_subj = OpenSSL::X509::Name.parse("/DC=org/DC=ruby-lang/CN=TestCA")
     ca_key = OpenSSL::TestUtils::TEST_KEY_RSA1024
diff --git a/test/test_pair.rb b/test/test_pair.rb
index f815eca0..4251f1ba 100644
--- a/test/test_pair.rb
+++ b/test/test_pair.rb
@@ -517,36 +517,36 @@ module OpenSSL::TestPairM
   end
 end
 
-class OpenSSL::TestEOF1 < Test::Unit::TestCase
+class OpenSSL::TestEOF1 < OpenSSL::TestCase
   include TestEOF
   include OpenSSL::SSLPair
   include OpenSSL::TestEOF1M
 end
 
-class OpenSSL::TestEOF1LowlevelSocket < Test::Unit::TestCase
+class OpenSSL::TestEOF1LowlevelSocket < OpenSSL::TestCase
   include TestEOF
   include OpenSSL::SSLPairLowlevelSocket
   include OpenSSL::TestEOF1M
 end
 
-class OpenSSL::TestEOF2 < Test::Unit::TestCase
+class OpenSSL::TestEOF2 < OpenSSL::TestCase
   include TestEOF
   include OpenSSL::SSLPair
   include OpenSSL::TestEOF2M
 end
 
-class OpenSSL::TestEOF2LowlevelSocket < Test::Unit::TestCase
+class OpenSSL::TestEOF2LowlevelSocket < OpenSSL::TestCase
   include TestEOF
   include OpenSSL::SSLPairLowlevelSocket
   include OpenSSL::TestEOF2M
 end
 
-class OpenSSL::TestPair < Test::Unit::TestCase
+class OpenSSL::TestPair < OpenSSL::TestCase
   include OpenSSL::SSLPair
   include OpenSSL::TestPairM
 end
 
-class OpenSSL::TestPairLowlevelSocket < Test::Unit::TestCase
+class OpenSSL::TestPairLowlevelSocket < OpenSSL::TestCase
   include OpenSSL::SSLPairLowlevelSocket
   include OpenSSL::TestPairM
 end
diff --git a/test/test_pkcs12.rb b/test/test_pkcs12.rb
index ba07d767..61fb4474 100644
--- a/test/test_pkcs12.rb
+++ b/test/test_pkcs12.rb
@@ -4,7 +4,7 @@ require_relative "utils"
 if defined?(OpenSSL::TestUtils)
 
 module OpenSSL
-  class TestPKCS12 < Test::Unit::TestCase
+  class TestPKCS12 < OpenSSL::TestCase
     include OpenSSL::TestUtils
 
     def setup
diff --git a/test/test_pkcs5.rb b/test/test_pkcs5.rb
index f38fd716..ad8132c2 100644
--- a/test/test_pkcs5.rb
+++ b/test/test_pkcs5.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: false
 require_relative 'utils'
 
-class OpenSSL::TestPKCS5 < Test::Unit::TestCase
+class OpenSSL::TestPKCS5 < OpenSSL::TestCase
 
   def test_pbkdf2_hmac_sha1_rfc6070_c_1_len_20
     p ="password"
diff --git a/test/test_pkcs7.rb b/test/test_pkcs7.rb
index ce99db50..dfe4c6ca 100644
--- a/test/test_pkcs7.rb
+++ b/test/test_pkcs7.rb
@@ -3,7 +3,7 @@ require_relative 'utils'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestPKCS7 < Test::Unit::TestCase
+class OpenSSL::TestPKCS7 < OpenSSL::TestCase
   def setup
     @rsa1024 = OpenSSL::TestUtils::TEST_KEY_RSA1024
     @rsa2048 = OpenSSL::TestUtils::TEST_KEY_RSA2048
diff --git a/test/test_pkey_dh.rb b/test/test_pkey_dh.rb
index a0eca53c..afd7a318 100644
--- a/test/test_pkey_dh.rb
+++ b/test/test_pkey_dh.rb
@@ -3,7 +3,7 @@ require_relative 'utils'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestPKeyDH < Test::Unit::TestCase
+class OpenSSL::TestPKeyDH < OpenSSL::TestCase
 
   NEW_KEYLEN = 256
 
diff --git a/test/test_pkey_dsa.rb b/test/test_pkey_dsa.rb
index eb3e4f1c..2c0e1fc2 100644
--- a/test/test_pkey_dsa.rb
+++ b/test/test_pkey_dsa.rb
@@ -4,7 +4,7 @@ require 'base64'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestPKeyDSA < Test::Unit::TestCase
+class OpenSSL::TestPKeyDSA < OpenSSL::TestCase
   def test_private
     key = OpenSSL::PKey::DSA.new(256)
     assert(key.private?)
@@ -20,7 +20,6 @@ class OpenSSL::TestPKeyDSA < Test::Unit::TestCase
     key = OpenSSL::PKey::DSA.new 256
     pem  = key.public_key.to_pem
     OpenSSL::PKey::DSA.new pem
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_new_break
@@ -84,7 +83,6 @@ end
     assert_equal(g, key.g)
     assert_equal(y, key.pub_key)
     assert_equal(nil, key.priv_key)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_DSAPublicKey_pem
@@ -109,7 +107,6 @@ fWLOqqkzFeRrYMDzUpl36XktY6Yq8EJYlW9pCMmBVNy/dQ==
     assert_equal(g, key.g)
     assert_equal(y, key.pub_key)
     assert_equal(nil, key.priv_key)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_DSA_PUBKEY_pem
@@ -135,7 +132,6 @@ YNMbNw==
     assert_equal(g, key.g)
     assert_equal(y, key.pub_key)
     assert_equal(nil, key.priv_key)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_export_format_is_DSA_PUBKEY_pem
@@ -165,7 +161,6 @@ YNMbNw==
     pub_key = OpenSSL::ASN1.decode(seq[1].value)
     assert_equal(OpenSSL::ASN1::INTEGER, pub_key.tag)
     assert_equal(key.pub_key, pub_key.value)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_private_key_der
@@ -174,7 +169,6 @@ YNMbNw==
     key2 = OpenSSL::PKey.read(der)
     assert(key2.private?)
     assert_equal(der, key2.to_der)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_private_key_pem
@@ -183,7 +177,6 @@ YNMbNw==
     key2 = OpenSSL::PKey.read(pem)
     assert(key2.private?)
     assert_equal(pem, key2.to_pem)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_public_key_der
@@ -192,7 +185,6 @@ YNMbNw==
     key2 = OpenSSL::PKey.read(der)
     assert(!key2.private?)
     assert_equal(der, key2.to_der)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_public_key_pem
@@ -201,7 +193,6 @@ YNMbNw==
     key2 = OpenSSL::PKey.read(pem)
     assert(!key2.private?)
     assert_equal(pem, key2.to_pem)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_private_key_pem_pw
@@ -216,7 +207,6 @@ YNMbNw==
     key2 = OpenSSL::PKey.read(pem, 'secret')
     assert(key2.private?)
     #omit pem equality check, will be different due to cipher iv
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_export_password_length
diff --git a/test/test_pkey_ec.rb b/test/test_pkey_ec.rb
index d3edcc47..c530ee06 100644
--- a/test/test_pkey_ec.rb
+++ b/test/test_pkey_ec.rb
@@ -3,7 +3,7 @@ require_relative 'utils'
 
 if defined?(OpenSSL::TestUtils) && defined?(OpenSSL::PKey::EC)
 
-class OpenSSL::TestEC < Test::Unit::TestCase
+class OpenSSL::TestEC < OpenSSL::TestCase
   def setup
     @data1 = 'foo'
     @data2 = 'bar' * 1000 # data too long for DSA sig
@@ -131,7 +131,6 @@ class OpenSSL::TestEC < Test::Unit::TestCase
     ec2 = OpenSSL::PKey.read(der)
     assert(ec2.private_key?)
     assert_equal(der, ec2.to_der)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_private_key_pem
@@ -140,7 +139,6 @@ class OpenSSL::TestEC < Test::Unit::TestCase
     ec2 = OpenSSL::PKey.read(pem)
     assert(ec2.private_key?)
     assert_equal(pem, ec2.to_pem)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_public_key_der
@@ -151,7 +149,6 @@ class OpenSSL::TestEC < Test::Unit::TestCase
     ec3 = OpenSSL::PKey.read(der)
     assert(!ec3.private_key?)
     assert_equal(der, ec3.to_der)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_public_key_pem
@@ -162,7 +159,6 @@ class OpenSSL::TestEC < Test::Unit::TestCase
     ec3 = OpenSSL::PKey.read(pem)
     assert(!ec3.private_key?)
     assert_equal(pem, ec3.to_pem)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_private_key_pem_pw
@@ -177,7 +173,6 @@ class OpenSSL::TestEC < Test::Unit::TestCase
     ec2 = OpenSSL::PKey.read(pem, 'secret')
     assert(ec2.private_key?)
     #omit pem equality check, will be different due to cipher iv
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_export_password_length
diff --git a/test/test_pkey_rsa.rb b/test/test_pkey_rsa.rb
index 165b1ec9..54fce2f5 100644
--- a/test/test_pkey_rsa.rb
+++ b/test/test_pkey_rsa.rb
@@ -4,7 +4,7 @@ require 'base64'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestPKeyRSA < Test::Unit::TestCase
+class OpenSSL::TestPKeyRSA < OpenSSL::TestCase
   def test_padding
     key = OpenSSL::PKey::RSA.new(512, 3)
 
@@ -180,7 +180,6 @@ AudJR1JobbIbDJrQu6AXnWh5k/YtAgMBAAE=
     assert_equal(nil, key.d)
     assert_equal(nil, key.p)
     assert_equal(nil, key.q)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_RSA_PUBKEY_pem
@@ -201,7 +200,6 @@ AwEAAQ==
     assert_equal(nil, key.d)
     assert_equal(nil, key.p)
     assert_equal(nil, key.q)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_export_format_is_RSA_PUBKEY
@@ -223,7 +221,6 @@ AwEAAQ==
     key = OpenSSL::PKey.read(der)
     assert(key.private?)
     assert_equal(der, key.to_der)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_private_key_pem
@@ -231,7 +228,6 @@ AwEAAQ==
     key = OpenSSL::PKey.read(pem)
     assert(key.private?)
     assert_equal(pem, key.to_pem)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_public_key_der
@@ -239,7 +235,6 @@ AwEAAQ==
     key = OpenSSL::PKey.read(der)
     assert(!key.private?)
     assert_equal(der, key.to_der)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_public_key_pem
@@ -247,7 +242,6 @@ AwEAAQ==
     key = OpenSSL::PKey.read(pem)
     assert(!key.private?)
     assert_equal(pem, key.to_pem)
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_private_key_pem_pw
@@ -261,7 +255,6 @@ AwEAAQ==
     key = OpenSSL::PKey.read(pem, 'secret')
     assert(key.private?)
     #omit pem equality check, will be different due to cipher iv
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_read_private_key_pem_pw_exception
@@ -272,7 +265,6 @@ AwEAAQ==
         raise RuntimeError
       end
     end
-    assert_equal([], OpenSSL.errors)
   end
 
   def test_export_password_length
@@ -306,7 +298,6 @@ AwEAAQ==
     assert_equal(key.n, pub_key.value[0].value)
     assert_equal(OpenSSL::ASN1::INTEGER, pub_key.value[1].tag)
     assert_equal(key.e, pub_key.value[1].value)
-    assert_equal([], OpenSSL.errors)
   end
 
 end
diff --git a/test/test_random.rb b/test/test_random.rb
index 8c69d543..defa09dd 100644
--- a/test/test_random.rb
+++ b/test/test_random.rb
@@ -4,7 +4,7 @@ begin
 rescue LoadError
 end
 
-class OpenSSL::TestRandom < Test::Unit::TestCase
+class OpenSSL::TestRandom < OpenSSL::TestCase
   def test_random_bytes
     assert_equal("", OpenSSL::Random.random_bytes(0))
     assert_equal(12, OpenSSL::Random.random_bytes(12).bytesize)
diff --git a/test/test_x509cert.rb b/test/test_x509cert.rb
index 72cb9e60..ae7a0f08 100644
--- a/test/test_x509cert.rb
+++ b/test/test_x509cert.rb
@@ -3,7 +3,7 @@ require_relative "utils"
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestX509Certificate < Test::Unit::TestCase
+class OpenSSL::TestX509Certificate < OpenSSL::TestCase
   def setup
     @rsa1024 = OpenSSL::TestUtils::TEST_KEY_RSA1024
     @rsa2048 = OpenSSL::TestUtils::TEST_KEY_RSA2048
@@ -14,9 +14,6 @@ class OpenSSL::TestX509Certificate < Test::Unit::TestCase
     @ee2 = OpenSSL::X509::Name.parse("/DC=org/DC=ruby-lang/CN=EE2")
   end
 
-  def teardown
-  end
-
   def issue_cert(*args)
     OpenSSL::TestUtils.issue_cert(*args)
   end
diff --git a/test/test_x509crl.rb b/test/test_x509crl.rb
index 7994ddea..fd66c975 100644
--- a/test/test_x509crl.rb
+++ b/test/test_x509crl.rb
@@ -3,7 +3,7 @@ require_relative "utils"
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestX509CRL < Test::Unit::TestCase
+class OpenSSL::TestX509CRL < OpenSSL::TestCase
   def setup
     @rsa1024 = OpenSSL::TestUtils::TEST_KEY_RSA1024
     @rsa2048 = OpenSSL::TestUtils::TEST_KEY_RSA2048
@@ -14,9 +14,6 @@ class OpenSSL::TestX509CRL < Test::Unit::TestCase
     @ee2 = OpenSSL::X509::Name.parse("/DC=org/DC=ruby-lang/CN=EE2")
   end
 
-  def teardown
-  end
-
   def issue_crl(*args)
     OpenSSL::TestUtils.issue_crl(*args)
   end
diff --git a/test/test_x509ext.rb b/test/test_x509ext.rb
index e6d49bb6..99e2eda5 100644
--- a/test/test_x509ext.rb
+++ b/test/test_x509ext.rb
@@ -3,7 +3,7 @@ require_relative 'utils'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestX509Extension < Test::Unit::TestCase
+class OpenSSL::TestX509Extension < OpenSSL::TestCase
   def setup
     @basic_constraints_value = OpenSSL::ASN1::Sequence([
       OpenSSL::ASN1::Boolean(true),   # CA
@@ -16,9 +16,6 @@ class OpenSSL::TestX509Extension < Test::Unit::TestCase
     ])
   end
 
-  def teardown
-  end
-
   def test_new
     ext = OpenSSL::X509::Extension.new(@basic_constraints.to_der)
     assert_equal("basicConstraints", ext.oid)
diff --git a/test/test_x509name.rb b/test/test_x509name.rb
index 56e79879..d26174ef 100644
--- a/test/test_x509name.rb
+++ b/test/test_x509name.rb
@@ -4,7 +4,7 @@ require_relative 'utils'
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestX509Name < Test::Unit::TestCase
+class OpenSSL::TestX509Name < OpenSSL::TestCase
   OpenSSL::ASN1::ObjectId.register(
     "1.2.840.113549.1.9.1", "emailAddress", "emailAddress")
   OpenSSL::ASN1::ObjectId.register(
@@ -15,9 +15,6 @@ class OpenSSL::TestX509Name < Test::Unit::TestCase
     @obj_type_tmpl.update(OpenSSL::X509::Name::OBJECT_TYPE_TEMPLATE)
   end
 
-  def teardown
-  end
-
   def test_s_new
     dn = [ ["C", "JP"], ["O", "example"], ["CN", "www.example.jp"] ]
     name = OpenSSL::X509::Name.new(dn)
diff --git a/test/test_x509req.rb b/test/test_x509req.rb
index ee2347b5..c473b47a 100644
--- a/test/test_x509req.rb
+++ b/test/test_x509req.rb
@@ -3,7 +3,7 @@ require_relative "utils"
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestX509Request < Test::Unit::TestCase
+class OpenSSL::TestX509Request < OpenSSL::TestCase
   def setup
     @rsa1024 = OpenSSL::TestUtils::TEST_KEY_RSA1024
     @rsa2048 = OpenSSL::TestUtils::TEST_KEY_RSA2048
diff --git a/test/test_x509store.rb b/test/test_x509store.rb
index 9964cc8f..6a443a7c 100644
--- a/test/test_x509store.rb
+++ b/test/test_x509store.rb
@@ -3,7 +3,7 @@ require_relative "utils"
 
 if defined?(OpenSSL::TestUtils)
 
-class OpenSSL::TestX509Store < Test::Unit::TestCase
+class OpenSSL::TestX509Store < OpenSSL::TestCase
   def setup
     @rsa1024 = OpenSSL::TestUtils::TEST_KEY_RSA1024
     @rsa2048 = OpenSSL::TestUtils::TEST_KEY_RSA2048
@@ -15,9 +15,6 @@ class OpenSSL::TestX509Store < Test::Unit::TestCase
     @ee2 = OpenSSL::X509::Name.parse("/DC=org/DC=ruby-lang/CN=EE2")
   end
 
-  def teardown
-  end
-
   def test_nosegv_on_cleanup
     cert  = OpenSSL::X509::Certificate.new
     store = OpenSSL::X509::Store.new
diff --git a/test/utils.rb b/test/utils.rb
index 8e21b977..8ce53290 100644
--- a/test/utils.rb
+++ b/test/utils.rb
@@ -182,7 +182,14 @@ AQjjxMXhwULlmuR/K+WwlaZPiLIBYalLAZQ7ZbOPeVkJ8ePao0eLAgEC
     end
   end
 
-  class OpenSSL::SSLTestCase < Test::Unit::TestCase
+  class OpenSSL::TestCase < Test::Unit::TestCase
+    def teardown
+      # OpenSSL error stack must be empty
+      assert_equal([], OpenSSL.errors)
+    end
+  end
+
+  class OpenSSL::SSLTestCase < OpenSSL::TestCase
     RUBY = EnvUtil.rubybin
     ITERATIONS = ($0 == __FILE__) ? 100 : 10
 
@@ -207,9 +214,6 @@ AQjjxMXhwULlmuR/K+WwlaZPiLIBYalLAZQ7ZbOPeVkJ8ePao0eLAgEC
       @server = nil
     end
 
-    def teardown
-    end
-
     def issue_cert(*arg)
       OpenSSL::TestUtils.issue_cert(*arg)
     end