[PATCH V2] sslutil - add tls 1.3 support - done during IETF101 Hackathon

[Codarren Velvindron]

# HG changeset patch
# User Codarren Velvindron <codarren at hackers.mu>
# Date 1522053522 -14400
#      Mon Mar 26 12:38:42 2018 +0400
# Node ID e11770b0adde6283965cafff1d6214a048417bfe
# Parent  6715e8035b4ff9379a80f5413a4e9148114ab256
sslutil: add tls 1.3 support
Done during the IETF101 Hackathon.

diff -r 6715e8035b4f -r e11770b0adde mercurial/help/config.txt
--- a/mercurial/help/config.txt	Sun Mar 25 11:58:05 2018 +0900
+++ b/mercurial/help/config.txt	Mon Mar 26 12:38:42 2018 +0400
@@ -1163,7 +1163,7 @@
     By default, the highest version of TLS supported by both client and server
     is used.
 
-    Allowed values are: ``tls1.0``, ``tls1.1``, ``tls1.2``.
+    Allowed values are: ``tls1.0``, ``tls1.1``, ``tls1.2``. ``tls1.3``.
 
     When running on an old Python version, only ``tls1.0`` is allowed since
     old versions of Python only support up to TLS 1.0.
diff -r 6715e8035b4f -r e11770b0adde mercurial/sslutil.py
--- a/mercurial/sslutil.py	Sun Mar 25 11:58:05 2018 +0900
+++ b/mercurial/sslutil.py	Mon Mar 26 12:38:42 2018 +0400
@@ -38,17 +38,20 @@
     'tls1.0',
     'tls1.1',
     'tls1.2',
+    'tls1.3',
 }
 
 hassni = getattr(ssl, 'HAS_SNI', False)
 
-# TLS 1.1 and 1.2 may not be supported if the OpenSSL Python is compiled
+# TLS 1.1,1.2 and 1.3 may not be supported if the OpenSSL Python is compiled
 # against doesn't support them.
 supportedprotocols = {'tls1.0'}
 if util.safehasattr(ssl, 'PROTOCOL_TLSv1_1'):
     supportedprotocols.add('tls1.1')
 if util.safehasattr(ssl, 'PROTOCOL_TLSv1_2'):
     supportedprotocols.add('tls1.2')
+if util.safehasattr(ssl, 'PROTOCOL_TLSv1_3'):
+    supportedprotocols.add('tls1.3')
 
 try:
     # ssl.SSLContext was added in 2.7.9 and presence indicates modern
@@ -293,7 +296,7 @@
     # Despite its name, PROTOCOL_SSLv23 selects the highest protocol
     # that both ends support, including TLS protocols. On legacy stacks,
     # the highest it likely goes is TLS 1.0. On modern stacks, it can
-    # support TLS 1.2.
+    # support TLS 1.2 or 1.3
     #
     # The PROTOCOL_TLSv* constants select a specific TLS version
     # only (as opposed to multiple versions). So the method for
@@ -323,6 +326,8 @@
         options |= ssl.OP_NO_TLSv1
     elif protocol == 'tls1.2':
         options |= ssl.OP_NO_TLSv1 | ssl.OP_NO_TLSv1_1
+    elif protocol == 'tls1.3':
+        options |= ssl.OP_NO_TLSv1 | ssl.OP_NO_TLSv1_1 | ssl.OP_NO_TLSv1_2
     else:
         raise error.Abort(_('this should not happen'))
 
@@ -542,6 +547,10 @@
         if 'tls1.2' not in supportedprotocols:
             raise error.Abort(_('TLS 1.2 not supported by this Python'))
         protocol = ssl.PROTOCOL_TLSv1_2
+    elif exactprotocol == 'tls1.3':
+        if 'tls1.3' not in supportedprotocols:
+            raise error.Abort(_('TLS 1.3 not supported by this Python'))
+        protocol = ssl.PROTOCOL_TLSv1_3
     elif exactprotocol:
         raise error.Abort(_('invalid value for serverexactprotocol: %s') %
                           exactprotocol)
diff -r 6715e8035b4f -r e11770b0adde tests/hghave.py
--- a/tests/hghave.py	Sun Mar 25 11:58:05 2018 +0900
+++ b/tests/hghave.py	Mon Mar 26 12:38:42 2018 +0400
@@ -523,6 +523,11 @@
     from mercurial import sslutil
     return 'tls1.2' in sslutil.supportedprotocols
 
+ at check("tls1.3", "TLS 1.3 protocol support")
+def has_tls1_3():
+    from mercurial import sslutil
+    return 'tls1.3' in sslutil.supportedprotocols
+
 @check("windows", "Windows")
 def has_windows():
     return os.name == 'nt'
diff -r 6715e8035b4f -r e11770b0adde tests/test-https.t
--- a/tests/test-https.t	Sun Mar 25 11:58:05 2018 +0900
+++ b/tests/test-https.t	Mon Mar 26 12:38:42 2018 +0400
@@ -442,8 +442,9 @@
   $ killdaemons.py hg0.pid
   $ killdaemons.py hg1.pid
   $ killdaemons.py hg2.pid
+  $ killdaemons.py hg3.pid
 
-#if sslcontext tls1.2
+#if sslcontext tls1.3
 Start servers running supported TLS versions
 
   $ cd test
@@ -456,6 +457,9 @@
   $ hg serve -p $HGPORT2 -d --pid-file=../hg2.pid --certificate=$PRIV \
   > --config devel.serverexactprotocol=tls1.2
   $ cat ../hg2.pid >> $DAEMON_PIDS
+  $ hg serve -p $HGPORT3 -d --pid-file=../hg3.pid --certificate=$PRIV \
+  > --config devel.serverexactprotocol=tls1.3
+  $ cat ../hg3.pid >> $DAEMON_PIDS
   $ cd ..
 
 Clients talking same TLS versions work
@@ -466,6 +470,8 @@
   5fed3813f7f5
   $ P="$CERTSDIR" hg --config hostsecurity.minimumprotocol=tls1.2 id https://localhost:$HGPORT2/
   5fed3813f7f5
+  $ P="$CERTSDIR" hg --config hostsecurity.minimumprotocol=tls1.3 id https://localhost:$HGPORT3/
+  5fed3813f7f5
 
 Clients requiring newer TLS version than what server supports fail