Fix time offset calculation.

ASN1_GENERALIZEDTIME and ASN1_UTCTIME may be specified using offsets,
even though that's not supported within certificates.

To convert the offset time back to GMT, the offsets are supposed to be
subtracted, not added. e.g. 1759-0500 == 2359+0100 == 2259Z.
Reviewed-by: NMatt Caswell <matt@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2654)

crypto/asn1/a_gentm.c

@@ -101,7 +101,7 @@ int asn1_generalizedtime_to_tm(struct tm *tm, const ASN1_GENERALIZEDTIME *d)
     if (a[o] == 'Z')
         o++;
     else if ((a[o] == '+') || (a[o] == '-')) {
-        int offsign = a[o] == '-' ? -1 : 1, offset = 0;
+        int offsign = a[o] == '-' ? 1 : -1, offset = 0;
         o++;
         if (o + 4 > l)
             goto err;

crypto/asn1/a_utctm.c

@@ -75,7 +75,7 @@ int asn1_utctime_to_tm(struct tm *tm, const ASN1_UTCTIME *d)
     if (a[o] == 'Z')
         o++;
     else if ((a[o] == '+') || (a[o] == '-')) {
-        int offsign = a[o] == '-' ? -1 : 1, offset = 0;
+        int offsign = a[o] == '-' ? 1 : -1, offset = 0;
         o++;
         if (o + 4 > l)
             goto err;

test/build.info

@@ -42,7 +42,8 @@ INCLUDE_MAIN___test_libtestutil_OLB = /INCLUDE=MAIN
           ssl_test_ctx_test ssl_test x509aux cipherlist_test asynciotest \
           bioprinttest sslapitest dtlstest sslcorrupttest bio_enc_test \
           pkey_meth_test uitest cipherbytes_test asn1_encode_test \
-          x509_time_test x509_dup_cert_test recordlentest
+          x509_time_test x509_dup_cert_test recordlentest \
+          time_offset_test
 
   SOURCE[aborttest]=aborttest.c
   INCLUDE[aborttest]=../include
@@ -345,6 +346,10 @@ INCLUDE_MAIN___test_libtestutil_OLB = /INCLUDE=MAIN
   INCLUDE[asn1_encode_test]=../include
   DEPEND[asn1_encode_test]=../libcrypto libtestutil.a
 
+  SOURCE[time_offset_test]=time_offset_test.c
+  INCLUDE[time_offset_test]=.. ../include
+  DEPEND[time_offset_test]=../libcrypto libtestutil.a
+
   # Internal test programs.  These are essentially a collection of internal
   # test routines.  Some of them need to reach internal symbols that aren't
   # available through the shared library (at least on Linux, Solaris, Windows

test/recipes/90-test_time_offset.t

+#! /usr/bin/env perl
+# Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
+#
+# Licensed under the OpenSSL license (the "License").  You may not use
+# this file except in compliance with the License.  You can obtain a copy
+# in the file LICENSE in the source distribution or at
+# https://www.openssl.org/source/license.html
+
+
+use OpenSSL::Test::Simple;
+
+simple_test("test_time_offset", "time_offset_test");

test/time_offset_test.c

+/*
+ * Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+/* time_t/offset (+/-XXXX) tests for ASN1 and X509 */
+
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include <openssl/asn1.h>
+#include <openssl/x509.h>
+#include "testutil.h"
+#include "e_os.h"
+
+typedef struct {
+    const char *data;
+    int time_result;
+    int type;
+} TESTDATA;
+
+
+/**********************************************************************
+ *
+ * Test driver
+ *
+ ***/
+
+static TESTDATA tests[] = {
+    { "20001201000000Z",      0, V_ASN1_GENERALIZEDTIME },
+    { "20001201010000+0100",  0, V_ASN1_GENERALIZEDTIME },
+    { "20001201050000+0500",  0, V_ASN1_GENERALIZEDTIME },
+    { "20001130230000-0100",  0, V_ASN1_GENERALIZEDTIME },
+    { "20001130190000-0500",  0, V_ASN1_GENERALIZEDTIME },
+    { "20001130190001-0500",  1, V_ASN1_GENERALIZEDTIME }, /* +1 second */
+    { "20001130185959-0500", -1, V_ASN1_GENERALIZEDTIME }, /* -1 second */
+    { "001201000000Z",        0, V_ASN1_UTCTIME },
+    { "001201010000+0100",    0, V_ASN1_UTCTIME },
+    { "001201050000+0500",    0, V_ASN1_UTCTIME },
+    { "001130230000-0100",    0, V_ASN1_UTCTIME },
+    { "001130190000-0500",    0, V_ASN1_UTCTIME },
+    { "001201000000-0000",    0, V_ASN1_UTCTIME },
+    { "001201000001-0000",    1, V_ASN1_UTCTIME }, /* +1 second */
+    { "001130235959-0000",   -1, V_ASN1_UTCTIME }, /* -1 second */
+    { "20001201000000+0000",  0, V_ASN1_GENERALIZEDTIME },
+    { "20001201000000+0100", -1, V_ASN1_GENERALIZEDTIME },
+    { "001201000000+0100",   -1, V_ASN1_UTCTIME },
+    { "20001201000000-0100",  1, V_ASN1_GENERALIZEDTIME },
+    { "001201000000-0100",    1, V_ASN1_UTCTIME },
+    { "20001201123400+1234",  0, V_ASN1_GENERALIZEDTIME },
+    { "20001130112600-1234",  0, V_ASN1_GENERALIZEDTIME },
+};
+
+static time_t the_time = 975628800;
+static ASN1_TIME the_asn1_time = {
+    15,
+    V_ASN1_GENERALIZEDTIME,
+    (unsigned char*)"20001201000000Z",
+    0
+};
+
+static int test_offset(int idx)
+{
+    ASN1_TIME at;
+    const TESTDATA *testdata = &tests[idx];
+    int ret = -2;
+    int day, sec;
+
+    at.data = (unsigned char*)testdata->data;
+    at.length = strlen(testdata->data);
+    at.type = testdata->type;
+
+    if (!TEST_true(ASN1_TIME_diff(&day, &sec, &the_asn1_time, &at))) {
+        TEST_info("ASN1_TIME_diff() failed for %s\n", at.data);
+        return 0;
+    }
+    if (day > 0)
+        ret = 1;
+    else if (day < 0)
+        ret = -1;
+    else if (sec > 0)
+        ret = 1;
+    else if (sec < 0)
+        ret = -1;
+    else
+        ret = 0;
+
+    if (!TEST_int_eq(testdata->time_result, ret)) {
+        TEST_info("ASN1_TIME_diff() test failed for %s day=%d sec=%d\n", at.data, day, sec);
+        return 0;
+    }
+
+    if (at.type == V_ASN1_UTCTIME)
+        ret = ASN1_UTCTIME_cmp_time_t(&at, the_time);
+    else
+        return 1; /* no other cmp_time_t() functions available, yet */
+
+    if (!TEST_int_eq(testdata->time_result, ret)) {
+        TEST_info("ASN1_UTCTIME_cmp_time_t() test failed for %s\n", at.data);
+        return 0;
+    }
+
+    return 1;
+}
+
+void register_tests()
+{
+    ADD_ALL_TESTS(test_offset, OSSL_NELEM(tests));
+}