Fix and improve SSL_MODE_SEND_FALLBACK_SCSV documentation.

Reviewed-by: Rich Salz <rsalz@openssl.org>

diff --git a/doc/ssl/SSL_CTX_set_mode.pod b/doc/ssl/SSL_CTX_set_mode.pod
index 0bcf5d2afcde4a211d4b8e24ad8ad2e9fe87384c..2a5aaa555e13ab058d81737f2ac5ec61350a2f87 100644 (file)
--- a/doc/ssl/SSL_CTX_set_mode.pod
+++ b/doc/ssl/SSL_CTX_set_mode.pod
@@ -71,12 +71,16 @@ SSL_CTX->freelist_max_len, which defaults to 32.  Using this flag can
 save around 34k per idle SSL connection.
 This flag has no effect on SSL v2 connections, or on DTLS connections.
 
 save around 34k per idle SSL connection.
 This flag has no effect on SSL v2 connections, or on DTLS connections.
 

-=item SSL_MODE_FALLBACK_SCSV
+=item SSL_MODE_SEND_FALLBACK_SCSV

 
 Send TLS_FALLBACK_SCSV in the ClientHello.
 
 Send TLS_FALLBACK_SCSV in the ClientHello.

-To be set by applications that reconnect with a downgraded protocol
+To be set only by applications that reconnect with a downgraded protocol

 version; see draft-ietf-tls-downgrade-scsv-00 for details.
 
 version; see draft-ietf-tls-downgrade-scsv-00 for details.
 

+DO NOT ENABLE THIS if your application attempts a normal handshake.
+Only use this in explicit fallback retries, following the guidance
+in draft-ietf-tls-downgrade-scsv-00.
+

 =back
 
 =head1 RETURN VALUES
 =back
 
 =head1 RETURN VALUES

diff --git a/ssl/ssl.h b/ssl/ssl.h
index a0db4f2a21fd5fe0fdd521473add6dcc5819037a..f45264ce59aa7e6b157c652a89f7948d84c24595 100644 (file)
--- a/ssl/ssl.h
+++ b/ssl/ssl.h
@@ -686,8 +686,13 @@ struct ssl_session_st
 #define SSL_MODE_SEND_CLIENTHELLO_TIME 0x00000020L
 #define SSL_MODE_SEND_SERVERHELLO_TIME 0x00000040L
 /* Send TLS_FALLBACK_SCSV in the ClientHello.
 #define SSL_MODE_SEND_CLIENTHELLO_TIME 0x00000020L
 #define SSL_MODE_SEND_SERVERHELLO_TIME 0x00000040L
 /* Send TLS_FALLBACK_SCSV in the ClientHello.

- * To be set by applications that reconnect with a downgraded protocol
- * version; see draft-ietf-tls-downgrade-scsv-00 for details. */
+ * To be set only by applications that reconnect with a downgraded protocol
+ * version; see draft-ietf-tls-downgrade-scsv-00 for details.
+ *
+ * DO NOT ENABLE THIS if your application attempts a normal handshake.
+ * Only use this in explicit fallback retries, following the guidance
+ * in draft-ietf-tls-downgrade-scsv-00.
+ */

 #define SSL_MODE_SEND_FALLBACK_SCSV 0x00000080L
 
 /* Cert related flags */
 #define SSL_MODE_SEND_FALLBACK_SCSV 0x00000080L
 
 /* Cert related flags */