bio: do not use the FILE BIO method in ossl_obj2bio()

Read everything from an IO object into a String first and use the
memory buffer BIO method just as we do for String inputs.

For MSVC builds, the FILE BIO method uses the "UPLINK" interface that
requires the application to provide OPENSSL_Applink() function. For us,
the "application" means ruby.exe, in which we can't do anything. As a
workaround, avoid using the FILE BIO method at all.

Usually private keys or X.509 certificates aren't that large and the
temporarily increased memory usage hopefully won't be an issue.

Fixes: https://github.com/ruby/openssl/issues/128

2 files changed, 15 insertions, 26 deletions

diff --git a/ext/openssl/ossl_bio.c b/ext/openssl/ossl_bio.c
index ae46ac43..8fa0b696 100644
--- a/ext/openssl/ossl_bio.c
+++ b/ext/openssl/ossl_bio.c
@@ -15,32 +15,12 @@ ossl_obj2bio(volatile VALUE *pobj)
     VALUE obj = *pobj;
     BIO *bio;
 
-    if (RB_TYPE_P(obj, T_FILE)) {
-	rb_io_t *fptr;
-	FILE *fp;
-	int fd;
-
-	GetOpenFile(obj, fptr);
-	rb_io_check_readable(fptr);
-	if ((fd = rb_cloexec_dup(FPTR_TO_FD(fptr))) < 0){
-	    rb_sys_fail(0);
-	}
-        rb_update_max_fd(fd);
-	if (!(fp = fdopen(fd, "r"))){
-	    int e = errno;
-	    close(fd);
-	    rb_syserr_fail(e, 0);
-	}
-	if (!(bio = BIO_new_fp(fp, BIO_CLOSE))){
-	    fclose(fp);
-	    ossl_raise(eOSSLError, NULL);
-	}
-    }
-    else {
-	StringValue(obj);
-	bio = BIO_new_mem_buf(RSTRING_PTR(obj), RSTRING_LENINT(obj));
-	if (!bio) ossl_raise(eOSSLError, NULL);
-    }
+    if (RB_TYPE_P(obj, T_FILE))
+	obj = rb_funcallv(obj, rb_intern("read"), 0, NULL);
+    StringValue(obj);
+    bio = BIO_new_mem_buf(RSTRING_PTR(obj), RSTRING_LENINT(obj));
+    if (!bio)
+	ossl_raise(eOSSLError, "BIO_new_mem_buf");
     *pobj = obj;
     return bio;
 }
diff --git a/test/test_x509cert.rb b/test/test_x509cert.rb
index 0cfe4402..5b2e712d 100644
--- a/test/test_x509cert.rb
+++ b/test/test_x509cert.rb
@@ -178,6 +178,15 @@ class OpenSSL::TestX509Certificate < OpenSSL::TestCase
     assert_equal(true, cert.check_private_key(@rsa2048))
   end
 
+  def test_read_from_file
+    cert = issue_cert(@ca, @rsa2048, 1, [], nil, nil)
+    Tempfile.create("cert") { |f|
+      f << cert.to_pem
+      f.rewind
+      assert_equal cert.to_der, OpenSSL::X509::Certificate.new(f).to_der
+    }
+  end
+
   private
 
   def certificate_error_returns_false