MINOR: ssl: set SSL_OP_PRIORITIZE_CHACHA
Sets OpenSSL 1.1.1's SSL_OP_PRIORITIZE_CHACHA unconditionally, as per [1]:
When SSL_OP_CIPHER_SERVER_PREFERENCE is set, temporarily reprioritize
ChaCha20-Poly1305 ciphers to the top of the server cipher list if a
ChaCha20-Poly1305 cipher is at the top of the client cipher list. This
helps those clients (e.g. mobile) use ChaCha20-Poly1305 if that cipher
is anywhere in the server cipher list; but still allows other clients to
use AES and other ciphers. Requires SSL_OP_CIPHER_SERVER_PREFERENCE.
[1] https://www.openssl.org/docs/man1.1.1/man3/SSL_CTX_clear_options.html
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 223184b..67b4b3a 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -10961,6 +10961,9 @@
Use the client's preference when selecting the cipher suite, by default
the server's preference is enforced. This option is also available on
global statement "ssl-default-bind-options".
+ Note that with OpenSSL >= 1.1.1 ChaCha20-Poly1305 is reprioritized anyway
+ (without setting this option), if a ChaCha20-Poly1305 cipher is at the top of
+ the client cipher list.
process <process-set>[/<thread-set>]
This restricts the list of processes and/or threads on which this listener is
diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index 7a602ad..5a003dc 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -1957,6 +1957,9 @@
#ifndef SSL_MODE_SMALL_BUFFERS /* needs small_records.patch */
#define SSL_MODE_SMALL_BUFFERS 0
#endif
+#ifndef SSL_OP_PRIORITIZE_CHACHA /* needs OpenSSL >= 1.1.1 */
+#define SSL_OP_PRIORITIZE_CHACHA 0
+#endif
#if (OPENSSL_VERSION_NUMBER < 0x1010000fL)
typedef enum { SET_CLIENT, SET_SERVER } set_context_func;
@@ -3711,6 +3714,7 @@
SSL_OP_SINGLE_DH_USE |
SSL_OP_SINGLE_ECDH_USE |
SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION |
+ SSL_OP_PRIORITIZE_CHACHA |
SSL_OP_CIPHER_SERVER_PREFERENCE;
long mode =
SSL_MODE_ENABLE_PARTIAL_WRITE |