Don't detect a downgrade where the server has a protocol version hole
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7013)
Matt Caswell
5 years ago
| 1664 | 1664 |
if (vers == TLS1_2_VERSION
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| 1665 | 1665 |
&& ssl_version_supported(s, TLS1_3_VERSION, NULL)) {
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| 1666 | 1666 |
*dgrd = DOWNGRADE_TO_1_2;
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| 1667 | |
} else if (!SSL_IS_DTLS(s) && vers < TLS1_2_VERSION
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| 1668 | |
&& (ssl_version_supported(s, TLS1_2_VERSION, NULL)
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| 1669 | |
|| ssl_version_supported(s, TLS1_3_VERSION, NULL))) {
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1667 |
} else if (!SSL_IS_DTLS(s)
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|
1668 |
&& vers < TLS1_2_VERSION
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1669 |
/*
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1670 |
* We need to ensure that a server that disables TLSv1.2
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|
1671 |
* (creating a hole between TLSv1.3 and TLSv1.1) can still
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1672 |
* complete handshakes with clients that support TLSv1.2 and
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1673 |
* below. Therefore we do not enable the sentinel if TLSv1.3 is
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1674 |
* enabled and TLSv1.2 is not.
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1675 |
*/
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1676 |
&& ssl_version_supported(s, TLS1_2_VERSION, NULL)) {
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| 1670 | 1677 |
*dgrd = DOWNGRADE_TO_1_1;
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| 1671 | 1678 |
} else {
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| 1672 | 1679 |
*dgrd = DOWNGRADE_NONE;
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| 44 | 44 |
$proxy->filter(\&downgrade_filter);
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| 45 | 45 |
my $testtype = DOWNGRADE_TO_TLS_1_2;
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| 46 | 46 |
$proxy->start() or plan skip_all => "Unable to start up Proxy for tests";
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| 47 | |
plan tests => 5;
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|
47 |
plan tests => 6;
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| 48 | 48 |
ok(TLSProxy::Message->fail(), "Downgrade TLSv1.3 to TLSv1.2");
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| 49 | 49 |
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| 50 | 50 |
#Test 2: Downgrade from TLSv1.3 to TLSv1.1
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| 73 | 73 |
"Fallback from TLSv1.3");
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| 74 | 74 |
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| 75 | 75 |
SKIP: {
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| 76 | |
skip "TLSv1.1 disabled", 1 if disabled("tls1_1");
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| 77 | |
#Test 5: A protocol "hole" should not be detected as a downgrade
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|
76 |
skip "TLSv1.1 disabled", 2 if disabled("tls1_1");
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|
77 |
#Test 5: A client side protocol "hole" should not be detected as a downgrade
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| 78 | 78 |
$proxy->clear();
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| 79 | 79 |
$proxy->filter(undef);
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| 80 | 80 |
$proxy->clientflags("-no_tls1_2");
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| 81 | 81 |
$proxy->start();
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| 82 | |
ok(TLSProxy::Message->success(), "TLSv1.2 protocol hole");
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|
82 |
ok(TLSProxy::Message->success(), "TLSv1.2 client-side protocol hole");
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|
83 |
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|
84 |
#Test 6: A server side protocol "hole" should not be detected as a downgrade
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|
85 |
$proxy->clear();
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|
86 |
$proxy->filter(undef);
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|
87 |
$proxy->serverflags("-no_tls1_2");
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|
88 |
$proxy->start();
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|
89 |
ok(TLSProxy::Message->success(), "TLSv1.2 server-side protocol hole");
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| 83 | 90 |
}
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| 84 | 91 |
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| 85 | 92 |
sub downgrade_filter
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