OpenSSL: remove ciphers without Forward Secrecy from default ciphersuite

Message ID 108af439-2141-7525-f30a-652822eda6e5@ipfire.org
State New
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Series
  • OpenSSL: remove ciphers without Forward Secrecy from default ciphersuite
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Commit Message

Peter Müller Aug. 1, 2020, 12:13 p.m. UTC
Ciphers not supplying (Perfect) Forward Secrecy are considered dangerous
since they allow content decryption in retrospect, if an attacker is
able to gain access to the servers' private key used for the
corresponding TLS session.

Since IPFire machines establish very few TLS connections by themselves, and
destinations (IPFire.org infrastructure, mirrors, IPS rule sources, etc.)
provide support for Forward Secrecy ciphers - some are even enforcing
them -, it is safe to drop support for anything else.

This patch reduces the OpenSSL default cipher list to:
TLS_AES_256_GCM_SHA384  TLSv1.3 Kx=any      Au=any  Enc=AESGCM(256) Mac=AEAD
TLS_CHACHA20_POLY1305_SHA256 TLSv1.3 Kx=any      Au=any  Enc=CHACHA20/POLY1305(256) Mac=AEAD
TLS_AES_128_GCM_SHA256  TLSv1.3 Kx=any      Au=any  Enc=AESGCM(128) Mac=AEAD
ECDHE-ECDSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AESGCM(256) Mac=AEAD
ECDHE-ECDSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=CHACHA20/POLY1305(256) Mac=AEAD
ECDHE-ECDSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AESGCM(128) Mac=AEAD
ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AESGCM(256) Mac=AEAD
ECDHE-RSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH     Au=RSA  Enc=CHACHA20/POLY1305(256) Mac=AEAD
ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AESGCM(128) Mac=AEAD
ECDHE-ECDSA-AES256-SHA384 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AES(256)  Mac=SHA384
ECDHE-ECDSA-CAMELLIA256-SHA384 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=Camellia(256) Mac=SHA384
ECDHE-RSA-AES256-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AES(256)  Mac=SHA384
ECDHE-RSA-CAMELLIA256-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=Camellia(256) Mac=SHA384
ECDHE-ECDSA-AES128-SHA256 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AES(128)  Mac=SHA256
ECDHE-ECDSA-CAMELLIA128-SHA256 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=Camellia(128) Mac=SHA256
ECDHE-RSA-AES128-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AES(128)  Mac=SHA256
ECDHE-RSA-CAMELLIA128-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=Camellia(128) Mac=SHA256
DHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(256) Mac=AEAD
DHE-RSA-CHACHA20-POLY1305 TLSv1.2 Kx=DH       Au=RSA  Enc=CHACHA20/POLY1305(256) Mac=AEAD
DHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(128) Mac=AEAD
DHE-RSA-AES256-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA256
DHE-RSA-CAMELLIA256-SHA256 TLSv1.2 Kx=DH       Au=RSA  Enc=Camellia(256) Mac=SHA256
DHE-RSA-AES128-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA256
DHE-RSA-CAMELLIA128-SHA256 TLSv1.2 Kx=DH       Au=RSA  Enc=Camellia(128) Mac=SHA256
ECDHE-ECDSA-AES256-SHA  TLSv1 Kx=ECDH     Au=ECDSA Enc=AES(256)  Mac=SHA1
ECDHE-ECDSA-AES128-SHA  TLSv1 Kx=ECDH     Au=ECDSA Enc=AES(128)  Mac=SHA1
ECDHE-RSA-AES256-SHA    TLSv1 Kx=ECDH     Au=RSA  Enc=AES(256)  Mac=SHA1
ECDHE-RSA-AES128-SHA    TLSv1 Kx=ECDH     Au=RSA  Enc=AES(128)  Mac=SHA1
DHE-RSA-AES256-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA1
DHE-RSA-CAMELLIA256-SHA SSLv3 Kx=DH       Au=RSA  Enc=Camellia(256) Mac=SHA1
DHE-RSA-AES128-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA1
DHE-RSA-CAMELLIA128-SHA SSLv3 Kx=DH       Au=RSA  Enc=Camellia(128) Mac=SHA1

Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
---
 src/patches/openssl-1.1.1d-default-cipherlist.patch | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Michael Tremer Aug. 4, 2020, 9:35 a.m. UTC | #1
Acked-by: Michael Tremer <michael.tremer@ipfire.org>

> On 1 Aug 2020, at 13:13, Peter Müller <peter.mueller@ipfire.org> wrote:
> 
> Ciphers not supplying (Perfect) Forward Secrecy are considered dangerous
> since they allow content decryption in retrospect, if an attacker is
> able to gain access to the servers' private key used for the
> corresponding TLS session.
> 
> Since IPFire machines establish very few TLS connections by themselves, and
> destinations (IPFire.org infrastructure, mirrors, IPS rule sources, etc.)
> provide support for Forward Secrecy ciphers - some are even enforcing
> them -, it is safe to drop support for anything else.
> 
> This patch reduces the OpenSSL default cipher list to:
> TLS_AES_256_GCM_SHA384  TLSv1.3 Kx=any      Au=any  Enc=AESGCM(256) Mac=AEAD
> TLS_CHACHA20_POLY1305_SHA256 TLSv1.3 Kx=any      Au=any  Enc=CHACHA20/POLY1305(256) Mac=AEAD
> TLS_AES_128_GCM_SHA256  TLSv1.3 Kx=any      Au=any  Enc=AESGCM(128) Mac=AEAD
> ECDHE-ECDSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AESGCM(256) Mac=AEAD
> ECDHE-ECDSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=CHACHA20/POLY1305(256) Mac=AEAD
> ECDHE-ECDSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AESGCM(128) Mac=AEAD
> ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AESGCM(256) Mac=AEAD
> ECDHE-RSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH     Au=RSA  Enc=CHACHA20/POLY1305(256) Mac=AEAD
> ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AESGCM(128) Mac=AEAD
> ECDHE-ECDSA-AES256-SHA384 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AES(256)  Mac=SHA384
> ECDHE-ECDSA-CAMELLIA256-SHA384 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=Camellia(256) Mac=SHA384
> ECDHE-RSA-AES256-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AES(256)  Mac=SHA384
> ECDHE-RSA-CAMELLIA256-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=Camellia(256) Mac=SHA384
> ECDHE-ECDSA-AES128-SHA256 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AES(128)  Mac=SHA256
> ECDHE-ECDSA-CAMELLIA128-SHA256 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=Camellia(128) Mac=SHA256
> ECDHE-RSA-AES128-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AES(128)  Mac=SHA256
> ECDHE-RSA-CAMELLIA128-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=Camellia(128) Mac=SHA256
> DHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(256) Mac=AEAD
> DHE-RSA-CHACHA20-POLY1305 TLSv1.2 Kx=DH       Au=RSA  Enc=CHACHA20/POLY1305(256) Mac=AEAD
> DHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(128) Mac=AEAD
> DHE-RSA-AES256-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA256
> DHE-RSA-CAMELLIA256-SHA256 TLSv1.2 Kx=DH       Au=RSA  Enc=Camellia(256) Mac=SHA256
> DHE-RSA-AES128-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA256
> DHE-RSA-CAMELLIA128-SHA256 TLSv1.2 Kx=DH       Au=RSA  Enc=Camellia(128) Mac=SHA256
> ECDHE-ECDSA-AES256-SHA  TLSv1 Kx=ECDH     Au=ECDSA Enc=AES(256)  Mac=SHA1
> ECDHE-ECDSA-AES128-SHA  TLSv1 Kx=ECDH     Au=ECDSA Enc=AES(128)  Mac=SHA1
> ECDHE-RSA-AES256-SHA    TLSv1 Kx=ECDH     Au=RSA  Enc=AES(256)  Mac=SHA1
> ECDHE-RSA-AES128-SHA    TLSv1 Kx=ECDH     Au=RSA  Enc=AES(128)  Mac=SHA1
> DHE-RSA-AES256-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA1
> DHE-RSA-CAMELLIA256-SHA SSLv3 Kx=DH       Au=RSA  Enc=Camellia(256) Mac=SHA1
> DHE-RSA-AES128-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA1
> DHE-RSA-CAMELLIA128-SHA SSLv3 Kx=DH       Au=RSA  Enc=Camellia(128) Mac=SHA1
> 
> Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
> ---
> src/patches/openssl-1.1.1d-default-cipherlist.patch | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/patches/openssl-1.1.1d-default-cipherlist.patch b/src/patches/openssl-1.1.1d-default-cipherlist.patch
> index 5ad7829e7..a3a48933e 100644
> --- a/src/patches/openssl-1.1.1d-default-cipherlist.patch
> +++ b/src/patches/openssl-1.1.1d-default-cipherlist.patch
> @@ -5,7 +5,7 @@
>   * This applies to ciphersuites for TLSv1.2 and below.
>   */
> -# define SSL_DEFAULT_CIPHER_LIST "ALL:!COMPLEMENTOFDEFAULT:!eNULL"
> -+# define SSL_DEFAULT_CIPHER_LIST "HIGH:+aRSA:+SHA384:+SHA256:+DH:+SHA:+kRSA:!eNULL:!aNULL:!PSK:!SRP:!AESCCM:!DSS"
> ++# define SSL_DEFAULT_CIPHER_LIST "HIGH:+aRSA:+SHA384:+SHA256:+DH:+SHA:!kRSA:!eNULL:!aNULL:!PSK:!SRP:!AESCCM:!DSS"
>  /* This is the default set of TLSv1.3 ciphersuites */
>  # if !defined(OPENSSL_NO_CHACHA) && !defined(OPENSSL_NO_POLY1305)
>  #  define TLS_DEFAULT_CIPHERSUITES "TLS_AES_256_GCM_SHA384:" \
> -- 
> 2.26.2

Patch

diff --git a/src/patches/openssl-1.1.1d-default-cipherlist.patch b/src/patches/openssl-1.1.1d-default-cipherlist.patch
index 5ad7829e7..a3a48933e 100644
--- a/src/patches/openssl-1.1.1d-default-cipherlist.patch
+++ b/src/patches/openssl-1.1.1d-default-cipherlist.patch
@@ -5,7 +5,7 @@ 
   * This applies to ciphersuites for TLSv1.2 and below.
   */
 -# define SSL_DEFAULT_CIPHER_LIST "ALL:!COMPLEMENTOFDEFAULT:!eNULL"
-+# define SSL_DEFAULT_CIPHER_LIST "HIGH:+aRSA:+SHA384:+SHA256:+DH:+SHA:+kRSA:!eNULL:!aNULL:!PSK:!SRP:!AESCCM:!DSS"
++# define SSL_DEFAULT_CIPHER_LIST "HIGH:+aRSA:+SHA384:+SHA256:+DH:+SHA:!kRSA:!eNULL:!aNULL:!PSK:!SRP:!AESCCM:!DSS"
  /* This is the default set of TLSv1.3 ciphersuites */
  # if !defined(OPENSSL_NO_CHACHA) && !defined(OPENSSL_NO_POLY1305)
  #  define TLS_DEFAULT_CIPHERSUITES "TLS_AES_256_GCM_SHA384:" \