bpo-31429: Define TLS cipher suite on build time by tiran · Pull Request #3532 · python/cpython

Expand Up @@ -115,6 +115,7 @@

from _ssl import HAS_SNI, HAS_ECDH, HAS_NPN, HAS_ALPN, HAS_TLSv1_3 from _ssl import _DEFAULT_CIPHERS from _ssl import _OPENSSL_API_VERSION

Expand Down Expand Up @@ -174,48 +175,7 @@ HAS_NEVER_CHECK_COMMON_NAME = hasattr(_ssl, 'HOSTFLAG_NEVER_CHECK_SUBJECT')

# Disable weak or insecure ciphers by default # (OpenSSL's default setting is 'DEFAULT:!aNULL:!eNULL') # Enable a better set of ciphers by default # This list has been explicitly chosen to: # * TLS 1.3 ChaCha20 and AES-GCM cipher suites # * Prefer cipher suites that offer perfect forward secrecy (DHE/ECDHE) # * Prefer ECDHE over DHE for better performance # * Prefer AEAD over CBC for better performance and security # * Prefer AES-GCM over ChaCha20 because most platforms have AES-NI # (ChaCha20 needs OpenSSL 1.1.0 or patched 1.0.2) # * Prefer any AES-GCM and ChaCha20 over any AES-CBC for better # performance and security # * Then Use HIGH cipher suites as a fallback # * Disable NULL authentication, NULL encryption, 3DES and MD5 MACs # for security reasons _DEFAULT_CIPHERS = ( 'TLS13-AES-256-GCM-SHA384:TLS13-CHACHA20-POLY1305-SHA256:' 'TLS13-AES-128-GCM-SHA256:' 'ECDH+AESGCM:ECDH+CHACHA20:DH+AESGCM:DH+CHACHA20:ECDH+AES256:DH+AES256:' 'ECDH+AES128:DH+AES:ECDH+HIGH:DH+HIGH:RSA+AESGCM:RSA+AES:RSA+HIGH:' '!aNULL:!eNULL:!MD5:!3DES' )
# Restricted and more secure ciphers for the server side # This list has been explicitly chosen to: # * TLS 1.3 ChaCha20 and AES-GCM cipher suites # * Prefer cipher suites that offer perfect forward secrecy (DHE/ECDHE) # * Prefer ECDHE over DHE for better performance # * Prefer AEAD over CBC for better performance and security # * Prefer AES-GCM over ChaCha20 because most platforms have AES-NI # * Prefer any AES-GCM and ChaCha20 over any AES-CBC for better # performance and security # * Then Use HIGH cipher suites as a fallback # * Disable NULL authentication, NULL encryption, MD5 MACs, DSS, RC4, and # 3DES for security reasons _RESTRICTED_SERVER_CIPHERS = ( 'TLS13-AES-256-GCM-SHA384:TLS13-CHACHA20-POLY1305-SHA256:' 'TLS13-AES-128-GCM-SHA256:' 'ECDH+AESGCM:ECDH+CHACHA20:DH+AESGCM:DH+CHACHA20:ECDH+AES256:DH+AES256:' 'ECDH+AES128:DH+AES:ECDH+HIGH:DH+HIGH:RSA+AESGCM:RSA+AES:RSA+HIGH:' '!aNULL:!eNULL:!MD5:!DSS:!RC4:!3DES' ) _RESTRICTED_SERVER_CIPHERS = _DEFAULT_CIPHERS
CertificateError = SSLCertVerificationError
Expand Down Expand Up @@ -393,8 +353,6 @@ class SSLContext(_SSLContext):
def __new__(cls, protocol=PROTOCOL_TLS, *args, **kwargs): self = _SSLContext.__new__(cls, protocol) if protocol != _SSLv2_IF_EXISTS: self.set_ciphers(_DEFAULT_CIPHERS) return self
def __init__(self, protocol=PROTOCOL_TLS): Expand Down Expand Up @@ -530,8 +488,6 @@ def create_default_context(purpose=Purpose.SERVER_AUTH, *, cafile=None, # verify certs and host name in client mode context.verify_mode = CERT_REQUIRED context.check_hostname = True elif purpose == Purpose.CLIENT_AUTH: context.set_ciphers(_RESTRICTED_SERVER_CIPHERS)
if cafile or capath or cadata: context.load_verify_locations(cafile, capath, cadata) Expand Down