gh-112454: Disable TLS-PSK if OpenSSL was built without PSK support (#112491)

If OpenSSL was built without PSK support, the python TLS-PSK
methods will raise "NotImplementedError" if called.

Add a constant "ssl.HAS_PSK" to check if TLS-PSK is supported

2 files changed, 3 insertions, 1 deletions

diff --git a/Lib/ssl.py b/Lib/ssl.py
index 36fca9d..d014849 100644
--- a/Lib/ssl.py
+++ b/Lib/ssl.py
@@ -116,7 +116,7 @@ except ImportError:
 
 from _ssl import (
     HAS_SNI, HAS_ECDH, HAS_NPN, HAS_ALPN, HAS_SSLv2, HAS_SSLv3, HAS_TLSv1,
-    HAS_TLSv1_1, HAS_TLSv1_2, HAS_TLSv1_3
+    HAS_TLSv1_1, HAS_TLSv1_2, HAS_TLSv1_3, HAS_PSK
 )
 from _ssl import _DEFAULT_CIPHERS, _OPENSSL_API_VERSION
 
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
index aecba89..3fdfa29 100644
--- a/Lib/test/test_ssl.py
+++ b/Lib/test/test_ssl.py
@@ -4259,6 +4259,7 @@ class ThreadedTests(unittest.TestCase):
                                  'Session refers to a different SSLContext.')
 
     @requires_tls_version('TLSv1_2')
+    @unittest.skipUnless(ssl.HAS_PSK, 'TLS-PSK disabled on this OpenSSL build')
     def test_psk(self):
         psk = bytes.fromhex('deadbeef')
 
@@ -4326,6 +4327,7 @@ class ThreadedTests(unittest.TestCase):
                 s.connect((HOST, server.port))
 
     @requires_tls_version('TLSv1_3')
+    @unittest.skipUnless(ssl.HAS_PSK, 'TLS-PSK disabled on this OpenSSL build')
     def test_psk_tls1_3(self):
         psk = bytes.fromhex('deadbeef')
         identity_hint = 'identity-hint'