[ruby/openssl] Include "additional data" message in OpenSSL errors

Error entries in the OpenSSL error queue may contain additional
contextual information associated with the error, which can be helpful
when debugging.

This "additional data" is currently only printed to stderr when
OpenSSL.debug is enabled. Let's include this in the exception messages
raised with ossl_raise(), too.

	$ ruby -Ilib -ropenssl -e'OpenSSL.debug=true; OpenSSL::SSL::SSLContext.new.ecdh_curves="P-256:not-a-curve"'
	-e:1: warning: error on stack: error:0A080106:SSL routines:gid_cb:passed invalid argument (group 'not-a-curve' cannot be set)
	-e:1:in `ecdh_curves=': passed invalid argument (group 'not-a-curve' cannot be set) (OpenSSL::SSL::SSLError)
		from -e:1:in `<main>'

https://github.com/ruby/openssl/commit/1c5bbdd68e

1 files changed, 17 insertions, 12 deletions

diff --git a/ext/openssl/ossl.c b/ext/openssl/ossl.c
index b1ba48c869..0bd2fa497e 100644
--- a/ext/openssl/ossl.c
+++ b/ext/openssl/ossl.c
@@ -272,23 +272,28 @@ VALUE
 ossl_make_error(VALUE exc, VALUE str)
 {
     unsigned long e;
+    const char *data;
+    int flags;
 
-    e = ERR_peek_last_error();
+    if (NIL_P(str))
+        str = rb_str_new(NULL, 0);
+
+#ifdef HAVE_ERR_GET_ERROR_ALL
+    e = ERR_peek_last_error_all(NULL, NULL, NULL, &data, &flags);
+#else
+    e = ERR_peek_last_error_line_data(NULL, NULL, &data, &flags);
+#endif
     if (e) {
-	const char *msg = ERR_reason_error_string(e);
+        const char *msg = ERR_reason_error_string(e);
 
-	if (NIL_P(str)) {
-	    if (msg) str = rb_str_new_cstr(msg);
-	}
-	else {
-	    if (RSTRING_LEN(str)) rb_str_cat2(str, ": ");
-	    rb_str_cat2(str, msg ? msg : "(null)");
-	}
-	ossl_clear_error();
+        if (RSTRING_LEN(str)) rb_str_cat_cstr(str, ": ");
+        rb_str_cat_cstr(str, msg ? msg : "(null)");
+        if (flags & ERR_TXT_STRING && data)
+            rb_str_catf(str, " (%s)", data);
+        ossl_clear_error();
     }
 
-    if (NIL_P(str)) str = rb_str_new(0, 0);
-    return rb_exc_new3(exc, str);
+    return rb_exc_new_str(exc, str);
 }
 
 void