AST-2016-001 http: Provide greater control of TLS and set modern defaults.

This change exposes the configuration of various aspects of the TLS
support and sets the default to the modern standards.

The TLS cipher is now set to the best values according to the
Mozilla OpSec team, different TLS versions can now be disabled, and
the cipher order can be forced to be that of the server instead of
the client.

ASTERISK-24972 #close

Change-Id: I0a10f2883f7559af5e48dee0901251dbf30d45b8

diff --git a/configs/samples/http.conf.sample b/configs/samples/http.conf.sample
index a4093bd88a759026430ba94baa080f7453bd6733..28437b0f5059d4b4b367f1d17bb61453cfbedf4a 100644 (file)
--- a/configs/samples/http.conf.sample
+++ b/configs/samples/http.conf.sample
@@ -90,6 +90,26 @@ bindaddr=127.0.0.1
 ; private in same .pem file.
 ; openssl req -new -x509 -days 365 -nodes -out /tmp/foo.pem -keyout /tmp/foo.pem
 ;
+; tlscipher=                             ; The list of allowed ciphers
+;                                        ; if none are specified the following cipher
+;                                        ; list will be used instead:
+; ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:
+; ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:
+; kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:
+; ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:
+; ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:
+; DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:
+; AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:
+; AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:
+; !EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA
+;
+; tlsdisablev1=yes                ; Disable TLSv1 support - if not set this defaults to "yes"
+; tlsdisablev11=yes               ; Disable TLSv1.1 support - if not set this defaults to "no"
+; tlsdisablev12=yes               ; Disable TLSv1.2 support - if not set this defaults to "no"
+;
+; tlsservercipherorder=yes        ; Use the server preference order instead of the client order
+;                                 ; Defaults to "yes"
+;
 ; The post_mappings section maps URLs to real paths on the filesystem.  If a
 ; POST is done from within an authenticated manager session to one of the
 ; configured POST mappings, then any files in the POST will be placed in the

diff --git a/include/asterisk/tcptls.h b/include/asterisk/tcptls.h
index a3f3f2884a7ec2e28c068a2c3eff1f4ac77dece8..3c5f4504caf4c69a42b27b30a2a2a4db8a745f60 100644 (file)
--- a/include/asterisk/tcptls.h
+++ b/include/asterisk/tcptls.h
@@ -87,7 +87,15 @@ enum ast_ssl_flags {
        /*! Use SSLv3 for outgoing client connections */
        AST_SSL_SSLV3_CLIENT = (1 << 4),
        /*! Use TLSv1 for outgoing client connections */
-       AST_SSL_TLSV1_CLIENT = (1 << 5)
+       AST_SSL_TLSV1_CLIENT = (1 << 5),
+       /*! Use server cipher order instead of the client order */
+       AST_SSL_SERVER_CIPHER_ORDER = (1 << 6),
+       /*! Disable TLSv1 support */
+       AST_SSL_DISABLE_TLSV1 = (1 << 7),
+       /*! Disable TLSv1.1 support */
+       AST_SSL_DISABLE_TLSV11 = (1 << 8),
+       /*! Disable TLSv1.2 support */
+       AST_SSL_DISABLE_TLSV12 = (1 << 9),
 };
 
 struct ast_tls_config {

diff --git a/main/http.c b/main/http.c
index 3a9d9ce9cbffc928cfbeb8e93e049fdeca8a1730..5ec94a7e19943c603b4286aa77498ad495b28c6a 100644 (file)
--- a/main/http.c
+++ b/main/http.c
@@ -2102,10 +2102,13 @@ static int __ast_http_load(int reload)
        }
        http_tls_cfg.pvtfile = ast_strdup("");
 
+       /* Apply modern intermediate settings according to the Mozilla OpSec team as of July 30th, 2015 but disable TLSv1 */
+       ast_set_flag(&http_tls_cfg.flags, AST_SSL_DISABLE_TLSV1 | AST_SSL_SERVER_CIPHER_ORDER);
+
        if (http_tls_cfg.cipher) {
                ast_free(http_tls_cfg.cipher);
        }
-       http_tls_cfg.cipher = ast_strdup("");
+       http_tls_cfg.cipher = ast_strdup("ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA");
 
        AST_RWLIST_WRLOCK(&uri_redirects);
        while ((redirect = AST_RWLIST_REMOVE_HEAD(&uri_redirects, entry))) {
@@ -2131,8 +2134,6 @@ static int __ast_http_load(int reload)
                        && strcasecmp(v->name, "tlsdontverifyserver")
                        && strcasecmp(v->name, "tlsclientmethod")
                        && strcasecmp(v->name, "sslclientmethod")
-                       && strcasecmp(v->name, "tlscipher")
-                       && strcasecmp(v->name, "sslcipher")
                        && !ast_tls_read_conf(&http_tls_cfg, &https_desc, v->name, v->value)) {
                        continue;
                }

diff --git a/main/tcptls.c b/main/tcptls.c
index 7ead094ac04f2f5e73e8ba3767ef6655878db24f..3941794630379276f7b24b5ded135dd79d3843ef 100644 (file)
--- a/main/tcptls.c
+++ b/main/tcptls.c
@@ -816,7 +816,8 @@ static int __ssl_setup(struct ast_tls_config *cfg, int client)
        return 0;
 #else
        int disable_ssl = 0;
- 
+       long ssl_opts = 0;
+
        if (!cfg->enabled) {
                return 0;
        }
@@ -864,11 +865,24 @@ static int __ssl_setup(struct ast_tls_config *cfg, int client)
         * them. SSLv23_*_method supports TLSv1+.
         */
        if (disable_ssl) {
-               long ssl_opts;
+               ssl_opts |= SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
+       }
+
+       if (ast_test_flag(&cfg->flags, AST_SSL_SERVER_CIPHER_ORDER)) {
+               ssl_opts |= SSL_OP_CIPHER_SERVER_PREFERENCE;
+       }
 
-               ssl_opts = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-               SSL_CTX_set_options(cfg->ssl_ctx, ssl_opts);
+       if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV1)) {
+               ssl_opts |= SSL_OP_NO_TLSv1;
        }
+       if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV11)) {
+               ssl_opts |= SSL_OP_NO_TLSv1_1;
+       }
+       if (ast_test_flag(&cfg->flags, AST_SSL_DISABLE_TLSV12)) {
+               ssl_opts |= SSL_OP_NO_TLSv1_2;
+       }
+
+       SSL_CTX_set_options(cfg->ssl_ctx, ssl_opts);
 
        SSL_CTX_set_verify(cfg->ssl_ctx,
                ast_test_flag(&cfg->flags, AST_SSL_VERIFY_CLIENT) ? SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT : SSL_VERIFY_NONE,
@@ -1232,6 +1246,14 @@ int ast_tls_read_conf(struct ast_tls_config *tls_cfg, struct ast_tcptls_session_
                        ast_clear_flag(&tls_cfg->flags, AST_SSL_TLSV1_CLIENT);
                        ast_clear_flag(&tls_cfg->flags, AST_SSL_SSLV3_CLIENT);
                }
+       } else if (!strcasecmp(varname, "tlsservercipherorder")) {
+               ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_SERVER_CIPHER_ORDER);
+       } else if (!strcasecmp(varname, "tlsdisablev1")) {
+               ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DISABLE_TLSV1);
+       } else if (!strcasecmp(varname, "tlsdisablev11")) {
+               ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DISABLE_TLSV11);
+       } else if (!strcasecmp(varname, "tlsdisablev12")) {
+               ast_set2_flag(&tls_cfg->flags, ast_true(value), AST_SSL_DISABLE_TLSV12);
        } else {
                return -1;
        }