ext/openssl: check argument type in OpenSSL::X509::Attribute#value=

The following code causes SEGV:

  OpenSSL::X509::Attribute.new("challengePassword", nil)

* ext/openssl/ossl_x509attr.c (ossl_x509attr_set_value): check that the
  argument is an instance of OpenSSL::ASN1::Data, before
  ossl_asn1_get_asn1type().
* test/openssl/test_x509attr.rb: add tests

2 files changed, 48 insertions, 0 deletions

diff --git a/ext/openssl/ossl_x509attr.c b/ext/openssl/ossl_x509attr.c
index d0f41c6bb8..be5f2dcf88 100644
--- a/ext/openssl/ossl_x509attr.c
+++ b/ext/openssl/ossl_x509attr.c
@@ -196,6 +196,7 @@ ossl_x509attr_set_value(VALUE self, VALUE value)
     X509_ATTRIBUTE *attr;
     ASN1_TYPE *a1type;
 
+    OSSL_Check_Kind(value, cASN1Data);
     if(!(a1type = ossl_asn1_get_asn1type(value)))
 	ossl_raise(eASN1Error, "could not get ASN1_TYPE");
     if(ASN1_TYPE_get(a1type) == V_ASN1_SEQUENCE){
diff --git a/test/openssl/test_x509attr.rb b/test/openssl/test_x509attr.rb
new file mode 100644
index 0000000000..c0885030f5
--- /dev/null
+++ b/test/openssl/test_x509attr.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: false
+require_relative "utils"
+
+if defined?(OpenSSL::TestUtils)
+
+class OpenSSL::TestX509Attribute < Test::Unit::TestCase
+  def test_new
+    ef = OpenSSL::X509::ExtensionFactory.new
+    val = OpenSSL::ASN1::Set.new([OpenSSL::ASN1::Sequence.new([
+      ef.create_extension("keyUsage", "keyCertSign", true)
+    ])])
+    attr = OpenSSL::X509::Attribute.new("extReq", val)
+    assert_equal("extReq", attr.oid)
+    assert_equal(val.to_der, attr.value.to_der)
+  end
+
+  def test_from_der
+    # oid: challengePassword, values: Set[UTF8String<"abc123">]
+    test_der = "\x30\x15\x06\x09\x2a\x86\x48\x86\xf7\x0d\x01\x09\x07\x31\x08" \
+      "\x0c\x06\x61\x62\x63\x31\x32\x33".b
+    attr = OpenSSL::X509::Attribute.new(test_der)
+    assert_equal(test_der, attr.to_der)
+    assert_equal("challengePassword", attr.oid)
+    assert_equal("abc123", attr.value.value[0].value)
+  end
+
+  def test_to_der
+    ef = OpenSSL::X509::ExtensionFactory.new
+    val = OpenSSL::ASN1::Set.new([OpenSSL::ASN1::Sequence.new([
+      ef.create_extension("keyUsage", "keyCertSign", true)
+    ])])
+    attr = OpenSSL::X509::Attribute.new("extReq", val)
+    expected = OpenSSL::ASN1::Sequence.new([
+      OpenSSL::ASN1::ObjectId.new("extReq"),
+      val
+    ])
+    assert_equal(expected.to_der, attr.to_der)
+  end
+
+  def test_invalid_value
+    assert_raise(TypeError) {
+      OpenSSL::X509::Attribute.new("challengePassword", "1234")
+    }
+  end
+end
+
+end