There are several weaknesses in how Diffie-Hellman key exchange has been deployed, allowing a man-in-the-middle attack named Logjam, more details here: https://weakdh.org. This patch improves the security in Nginx server, generating 2048bit DH-Parameters or longer when using 2048bit RSA keys. Some parameters before patch: echo | openssl s_client -connect localhost:8001 -cipher "DH" Cipher : DHE-RSA-AES256-GCM-SHA384 New, TLSv1/SSLv3, Cipher is DHE-RSA-AES256-GCM-SHA384 Server public key is 2048 bit Server Temp Key: DH, 1024 bits Some parameters after patch: echo | openssl s_client -connect localhost:8001 -cipher "DH" Cipher : DHE-RSA-AES256-GCM-SHA384 New, TLSv1/SSLv3, Cipher is DHE-RSA-AES256-GCM-SHA384 Server public key is 2048 bit Server Temp Key: DH, 2048 bits (*) This patch also changes the Ciphers allowed by Nginx, change build scripts and the RPM spec file to deliver new file: dhparams.pem. Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo@linux.vnet.ibm.com> --- Makefile.am | 1 + contrib/DEBIAN/control.in | 1 + contrib/kimchi.spec.fedora.in | 1 + contrib/kimchi.spec.suse.in | 1 + src/Makefile.am | 8 +++++++- src/kimchi/proxy.py | 6 +++++- src/nginx/Makefile.am | 2 ++ src/nginx/kimchi.conf.in | 4 +++- 8 files changed, 21 insertions(+), 3 deletions(-) diff --git a/Makefile.am b/Makefile.am index 46b0b5b..1a0c8e7 100644 --- a/Makefile.am +++ b/Makefile.am @@ -133,6 +133,7 @@ install-data-local: touch $(DESTDIR)/var/log/kimchi/kimchi-access.log touch $(DESTDIR)/var/log/kimchi/kimchi-error.log mkdir -p $(DESTDIR)/etc/kimchi/ + $(INSTALL_DATA) src/dhparams.pem $(DESTDIR)/etc/kimchi/dhparams.pem touch $(DESTDIR)/etc/nginx/conf.d/kimchi.conf uninstall-local: diff --git a/contrib/DEBIAN/control.in b/contrib/DEBIAN/control.in index 0747d0f..a288e9b 100644 --- a/contrib/DEBIAN/control.in +++ b/contrib/DEBIAN/control.in @@ -30,6 +30,7 @@ Depends: python-cherrypy3 (>= 3.2.0), libguestfs-tools, spice-html5 Build-Depends: libxslt, + openssl, python-lxml Maintainer: Aline Manera <alinefm@br.ibm.com> Description: Kimchi web server diff --git a/contrib/kimchi.spec.fedora.in b/contrib/kimchi.spec.fedora.in index dc5533a..183fd43 100644 --- a/contrib/kimchi.spec.fedora.in +++ b/contrib/kimchi.spec.fedora.in @@ -34,6 +34,7 @@ Requires: python-ldap Requires: python-libguestfs Requires: libguestfs-tools BuildRequires: libxslt +BuildRequires: openssl BuildRequires: python-lxml %if 0%{?rhel} >= 6 || 0%{?fedora} >= 19 diff --git a/contrib/kimchi.spec.suse.in b/contrib/kimchi.spec.suse.in index 5681a60..fa55cc5 100644 --- a/contrib/kimchi.spec.suse.in +++ b/contrib/kimchi.spec.suse.in @@ -34,6 +34,7 @@ Requires: open-iscsi Requires: python-libguestfs Requires: guestfs-tools BuildRequires: libxslt-tools +BuildRequires: openssl BuildRequires: python-lxml %if 0%{?sles_version} == 11 diff --git a/src/Makefile.am b/src/Makefile.am index 38d231c..e0e0821 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -45,4 +45,10 @@ kimchid: kimchid.in Makefile kimchi.conf: kimchi.conf.in Makefile $(do_substitution) < kimchi.conf.in > kimchi.conf -CLEANFILES = $(bin_SCRIPTS) $(BUILT_SOURCES) +# Generate unique Diffie-Hellman group with 2048-bit +all-local: dhparams.pem + +dhparams.pem: + openssl dhparam -out dhparams.pem 2048 + +CLEANFILES = $(bin_SCRIPTS) $(BUILT_SOURCES) dhparams.pem diff --git a/src/kimchi/proxy.py b/src/kimchi/proxy.py index e3e35b4..5dcca65 100644 --- a/src/kimchi/proxy.py +++ b/src/kimchi/proxy.py @@ -68,6 +68,9 @@ def _create_proxy_config(options): with open(key, "w") as f: f.write(ssl_gen.key_pem()) + # Setting up Diffie-Hellman group with 2048-bit file + dhparams_pem = os.path.join(config_dir, "dhparams.pem") + # Read template file and create a new config file # with the specified parameters. with open(os.path.join(nginx_config_dir, "kimchi.conf.in")) as template: @@ -78,7 +81,8 @@ def _create_proxy_config(options): kimchid_port=options.cherrypy_port, proxy_ssl_port=options.ssl_port, cert_pem=cert, cert_key=key, - max_body_size=eval(options.max_body_size)) + max_body_size=eval(options.max_body_size), + dhparams_pem=dhparams_pem) # Write file to be used for nginx. config_file = open(os.path.join(nginx_config_dir, "kimchi.conf"), "w") diff --git a/src/nginx/Makefile.am b/src/nginx/Makefile.am index 0241b37..c754947 100644 --- a/src/nginx/Makefile.am +++ b/src/nginx/Makefile.am @@ -21,3 +21,5 @@ EXTRA_DIST = kimchi.conf.in confdir = $(sysconfdir)/nginx/conf.d dist_conf_DATA = kimchi.conf.in + +CLEANFILES = kimchi.conf diff --git a/src/nginx/kimchi.conf.in b/src/nginx/kimchi.conf.in index 3ecbde4..b0faea3 100644 --- a/src/nginx/kimchi.conf.in +++ b/src/nginx/kimchi.conf.in @@ -53,7 +53,9 @@ http { ssl_certificate ${cert_pem}; ssl_certificate_key ${cert_key}; ssl_protocols TLSv1 TLSv1.1 TLSv1.2; - ssl_ciphers ECDH@STRENGTH:DH@STRENGTH:HIGH:!RC4:!MD5:!DES:!aNULL:!eNULL; + ssl_ciphers '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:@STRENGTH'; + ssl_prefer_server_ciphers on; + ssl_dhparam ${dhparams_pem}; add_header Strict-Transport-Security "max-age=31536000; includeSubdomains;"; add_header X-Frame-Options DENY; -- 2.1.0