security: improve the default TLS ciphers

ethomson · ethomson · commit e014b10e78b3 · 2024-12-16T10:07:10.000Z
Update our default cipher list to the most recent "intermediate" configuration from Mozilla's SSL cipher list, which is "recommended cnofiguration for a general-purpose server". https://wiki.mozilla.org/Security/Server_Side_TLS This removes many outdated ciphers that are no longer practically supported by servers, including GitHub, GitLab, and Bitbucket.
diff --git a/src/libgit2/streams/mbedtls.c b/src/libgit2/streams/mbedtls.c
@@ -39,8 +39,8 @@
 
 #undef inline
 
-#define GIT_SSL_DEFAULT_CIPHERS "TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256:TLS-ECDHE-RSA-WITH-AES-128-GCM-SHA256:TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384:TLS-ECDHE-RSA-WITH-AES-256-GCM-SHA384:TLS-DHE-RSA-WITH-AES-128-GCM-SHA256:TLS-DHE-DSS-WITH-AES-128-GCM-SHA256:TLS-DHE-RSA-WITH-AES-256-GCM-SHA384:TLS-DHE-DSS-WITH-AES-256-GCM-SHA384:TLS-ECDHE-ECDSA-WITH-AES-128-CBC-SHA256:TLS-ECDHE-RSA-WITH-AES-128-CBC-SHA256:TLS-ECDHE-ECDSA-WITH-AES-128-CBC-SHA:TLS-ECDHE-RSA-WITH-AES-128-CBC-SHA:TLS-ECDHE-ECDSA-WITH-AES-256-CBC-SHA384:TLS-ECDHE-RSA-WITH-AES-256-CBC-SHA384:TLS-ECDHE-ECDSA-WITH-AES-256-CBC-SHA:TLS-ECDHE-RSA-WITH-AES-256-CBC-SHA:TLS-DHE-RSA-WITH-AES-128-CBC-SHA256:TLS-DHE-RSA-WITH-AES-256-CBC-SHA256:TLS-DHE-RSA-WITH-AES-128-CBC-SHA:TLS-DHE-RSA-WITH-AES-256-CBC-SHA:TLS-DHE-DSS-WITH-AES-128-CBC-SHA256:TLS-DHE-DSS-WITH-AES-256-CBC-SHA256:TLS-DHE-DSS-WITH-AES-128-CBC-SHA:TLS-DHE-DSS-WITH-AES-256-CBC-SHA:TLS-RSA-WITH-AES-128-GCM-SHA256:TLS-RSA-WITH-AES-256-GCM-SHA384:TLS-RSA-WITH-AES-128-CBC-SHA256:TLS-RSA-WITH-AES-256-CBC-SHA256:TLS-RSA-WITH-AES-128-CBC-SHA:TLS-RSA-WITH-AES-256-CBC-SHA"
-#define GIT_SSL_DEFAULT_CIPHERS_COUNT 30
+#define GIT_SSL_DEFAULT_CIPHERS "TLS1-3-AES-128-GCM-SHA256:TLS1-3-AES-256-GCM-SHA384:TLS1-3-CHACHA20-POLY1305-SHA256:TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256:TLS-ECDHE-RSA-WITH-AES-128-GCM-SHA256:TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384:TLS-ECDHE-RSA-WITH-AES-256-GCM-SHA384:TLS-ECDHE-ECDSA-WITH-CHACHA20-POLY1305-SHA256:TLS-ECDHE-RSA-WITH-CHACHA20-POLY1305-SHA256:TLS-DHE-RSA-WITH-AES-128-GCM-SHA256:TLS-DHE-RSA-WITH-AES-256-GCM-SHA384:TLS-DHE-RSA-WITH-CHACHA20-POLY1305-SHA256"
+#define GIT_SSL_DEFAULT_CIPHERS_COUNT 12
 
 static int ciphers_list[GIT_SSL_DEFAULT_CIPHERS_COUNT];
 
diff --git a/src/libgit2/streams/openssl.c b/src/libgit2/streams/openssl.c
@@ -40,7 +40,7 @@ extern char *git__ssl_ciphers;
 
 SSL_CTX *git__ssl_ctx;
 
-#define GIT_SSL_DEFAULT_CIPHERS "ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-DSS-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA:DHE-DSS-AES128-SHA256:DHE-DSS-AES256-SHA256:DHE-DSS-AES128-SHA:DHE-DSS-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA"
+#define GIT_SSL_DEFAULT_CIPHERS "TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-CHACHA20-POLY1305"
 
 
 static BIO_METHOD *git_stream_bio_method;
