diff -r 89aa669dcc61 Doc/library/ssl.rst --- a/Doc/library/ssl.rst Thu Mar 20 18:00:35 2014 -0500 +++ b/Doc/library/ssl.rst Fri Mar 21 20:45:12 2014 -0400 @@ -1665,17 +1665,10 @@ enabled when negotiating a SSL session is possible through the :meth:`SSLContext.set_ciphers` method. Starting from Python 3.2.3, the ssl module disables certain weak ciphers by default, but you may want -to further restrict the cipher choice. For example:: - - context = ssl.SSLContext(ssl.PROTOCOL_TLSv1) - context.set_ciphers('HIGH:!aNULL:!eNULL') - -The ``!aNULL:!eNULL`` part of the cipher spec is necessary to disable ciphers -which don't provide both encryption and authentication. Be sure to read -OpenSSL's documentation about the `cipher list -format `_. -If you want to check which ciphers are enabled by a given cipher list, -use the ``openssl ciphers`` command on your system. +to further restrict the cipher choice. Be sure to read OpenSSL's documentation +about the `cipher list format `_. +If you want to check which ciphers are enabled by a given cipher list, use the +``openssl ciphers`` command on your system. Multi-processing ^^^^^^^^^^^^^^^^ diff -r 89aa669dcc61 Lib/ssl.py --- a/Lib/ssl.py Thu Mar 20 18:00:35 2014 -0500 +++ b/Lib/ssl.py Fri Mar 21 20:45:12 2014 -0400 @@ -162,14 +162,37 @@ # Disable weak or insecure ciphers by default # (OpenSSL's default setting is 'DEFAULT:!aNULL:!eNULL') -_DEFAULT_CIPHERS = 'DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2' +# Enable a better set of ciphers by default +# This list has been explicitly chosen to: +# * Prefer cipher suites that offer perfect forward secrecy (DHE/ECDHE) +# * Prefer ECDHE over DHE for better performance +# * Prefer any AES-GCM over any AES-CBC for better performance and security +# * Then Use HIGH cipher suites as a fallback +# * Then Use 3DES as fallback which is secure but slow +# * Finally use RC4 as a fallback which is problematic but needed for +# * compatability some times. +# * Disable NULL authentication, NULL encryption, and MD5 MACs for security +# reasons +_DEFAULT_CIPHERS = ( + 'ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+HIGH:' + 'DH+HIGH:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+HIGH:RSA+3DES:ECDH+RC4:' + 'DH+RC4:RSA+RC4:!aNULL:!eNULL:!MD5' +) -# restricted and more secure ciphers -# HIGH: high encryption cipher suites with key length >= 128 bits (no MD5) -# !aNULL: only authenticated cipher suites (no anonymous DH) -# !RC4: no RC4 streaming cipher, RC4 is broken -# !DSS: RSA is preferred over DSA -_RESTRICTED_CIPHERS = 'HIGH:!aNULL:!RC4:!DSS' +# Restricted and more secure ciphers +# This list has been explicitly chosen to: +# * Prefer cipher suites that offer perfect forward secrecy (DHE/ECDHE) +# * Prefer ECDHE over DHE for better performance +# * Prefer any AES-GCM over any AES-CBC for better performance and security +# * Then Use HIGH cipher suites as a fallback +# * Then Use 3DES as fallback which is secure but slow +# * Disable NULL authentication, NULL encryption, MD5 MACs, DSS, and RC4 for +# security reasons +_RESTRICTED_CIPHERS = ( + 'ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+HIGH:' + 'DH+HIGH:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+HIGH:RSA+3DES:!aNULL:' + '!eNULL:!MD5:!DSS:!RC4' +) class CertificateError(ValueError):