Dr. Matthias St. Pierre 849529257c drbg: ensure fork-safety without using a pthread_atfork handler
When the new OpenSSL CSPRNG was introduced in version 1.1.1,
it was announced in the release notes that it would be fork-safe,
which the old CSPRNG hadn't been.

The fork-safety was implemented using a fork count, which was
incremented by a pthread_atfork handler. Initially, this handler
was enabled by default. Unfortunately, the default behaviour
had to be changed for other reasons in commit b5319bdbd095, so
the new OpenSSL CSPRNG failed to keep its promise.

This commit restores the fork-safety using a different approach.
It replaces the fork count by a fork id, which coincides with
the process id on UNIX-like operating systems and is zero on other
operating systems. It is used to detect when an automatic reseed
after a fork is necessary.

To prevent a future regression, it also adds a test to verify that
the child reseeds after fork.

CVE-2019-1549

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9832)
2019-09-11 11:22:18 +02:00
..
2019-09-11 17:52:30 +10:00
2018-12-11 20:57:31 +10:00
2019-07-02 14:22:29 +02:00
2019-09-04 17:26:07 +02:00
2019-08-15 14:33:06 +01:00
2019-07-01 10:09:22 +02:00
2019-08-09 17:29:39 +01:00
2018-12-09 22:02:48 -05:00
2019-09-09 14:43:57 +02:00
2019-07-02 14:22:29 +02:00
2019-02-16 00:29:20 +01:00
2018-12-09 22:02:49 -05:00
2019-03-28 15:02:19 +10:00
2019-07-02 14:22:29 +02:00
2019-02-13 12:11:49 +01:00
2019-06-20 17:16:50 +10:00
2019-08-29 11:07:30 +01:00
2019-07-01 13:32:46 -04:00
2019-07-02 14:22:29 +02:00
2019-08-18 21:45:16 +02:00
2019-08-09 17:29:39 +01:00
2019-07-02 14:22:29 +02:00

How to add recipes
==================

For any test that you want to perform, you write a script located in
test/recipes/, named {nn}-test_{name}.t, where {nn} is a two digit number and
{name} is a unique name of your choice.

Please note that if a test involves a new testing executable, you will need to
do some additions in test/build.info. Please refer to the section "Changes to 
test/build.info" below.


Naming conventions
=================

A test executable is named test/{name}test.c

A test recipe is named test/recipes/{nn}-test_{name}.t, where {nn} is a two
digit number and {name} is a unique name of your choice.

The number {nn} is (somewhat loosely) grouped as follows:

00-04  sanity, internal and essential API tests
05-09  individual symmetric cipher algorithms
10-14  math (bignum)
15-19  individual asymmetric cipher algorithms
20-24  openssl commands (some otherwise not tested)
25-29  certificate forms, generation and verification
30-35  engine and evp
60-79  APIs
   70  PACKET layer
80-89  "larger" protocols (CA, CMS, OCSP, SSL, TSA)
90-98  misc
99     most time consuming tests [such as test_fuzz]


A recipe that just runs a test executable
=========================================

A script that just runs a program looks like this:

    #! /usr/bin/perl

    use OpenSSL::Test::Simple;

    simple_test("test_{name}", "{name}test", "{name}");

{name} is the unique name you have chosen for your test.

The second argument to `simple_test' is the test executable, and `simple_test'
expects it to be located in test/

For documentation on OpenSSL::Test::Simple, do
`perldoc util/perl/OpenSSL/Test/Simple.pm'.


A recipe that runs a more complex test
======================================

For more complex tests, you will need to read up on Test::More and
OpenSSL::Test.  Test::More is normally preinstalled, do `man Test::More' for
documentation.  For OpenSSL::Test, do `perldoc util/perl/OpenSSL/Test.pm'.

A script to start from could be this:

    #! /usr/bin/perl

    use strict;
    use warnings;
    use OpenSSL::Test;

    setup("test_{name}");

    plan tests => 2;                # The number of tests being performed

    ok(test1, "test1");
    ok(test2, "test1");

    sub test1
    {
        # test feature 1
    }

    sub test2
    {
        # test feature 2
    }


Changes to test/build.info
==========================

Whenever a new test involves a new test executable you need to do the
following (at all times, replace {NAME} and {name} with the name of your
test):

* add {name} to the list of programs under PROGRAMS_NO_INST

* create a three line description of how to build the test, you will have
to modify the include paths and source files if you don't want to use the
basic test framework:

    SOURCE[{name}]={name}.c
    INCLUDE[{name}]=.. ../include ../apps/include
    DEPEND[{name}]=../libcrypto libtestutil.a

Generic form of C test executables
==================================

    #include "testutil.h"

    static int my_test(void)
    {
        int testresult = 0;                 /* Assume the test will fail    */
        int observed;

        observed = function();              /* Call the code under test     */
        if (!TEST_int_eq(observed, 2))      /* Check the result is correct  */
            goto end;                       /* Exit on failure - optional   */

        testresult = 1;                     /* Mark the test case a success */
    end:
        cleanup();                          /* Any cleanup you require      */
        return testresult;
    }

    int setup_tests(void)
    {
        ADD_TEST(my_test);                  /* Add each test separately     */
        return 1;                           /* Indicate success             */
    }

You should use the TEST_xxx macros provided by testutil.h to test all failure
conditions.  These macros produce an error message in a standard format if the
condition is not met (and nothing if the condition is met).  Additional
information can be presented with the TEST_info macro that takes a printf
format string and arguments.  TEST_error is useful for complicated conditions,
it also takes a printf format string and argument.  In all cases the TEST_xxx
macros are guaranteed to evaluate their arguments exactly once.  This means
that expressions with side effects are allowed as parameters.  Thus,

    if (!TEST_ptr(ptr = OPENSSL_malloc(..)))

works fine and can be used in place of:

    ptr = OPENSSL_malloc(..);
    if (!TEST_ptr(ptr))

The former produces a more meaningful message on failure than the latter.