On Sat, Apr 09, 2016 at 12:01:20PM -0700, jaso...@mail-central.com wrote:
> While looking through the Postfix default configs about TLS ciphers, I
> noticed these
>
> grep -i " anull" main.cf.default
> tls_export_cipherlist =
> aNULL:-aNULL:HIGH:MEDIUM:LOW:EXPORT:+RC4:@STRENGTH
> tls_high_cipherlist = aNULL:-aNULL:HIGH:@STRENGTH
> tls_low_cipherlist = aNULL:-aNULL:HIGH:MEDIUM:LOW:+RC4:@STRENGTH
> tls_medium_cipherlist = aNULL:-aNULL:HIGH:MEDIUM:+RC4:@STRENGTH
>
> What's the reason for the
>
> aNULL:-aNULL
The most recently removed ciphers are at the front of the list when
ciphers are restored. Therefore, "aNULL:-aNULL:ALL:@STRENGTH" is
different from "ALL:@STRENGTH" in that at any given strength the
aNULL ciphers are listed first. There's not much point in enabling
aNULL ciphers if they are not used when supported at both ends (and
the client is ignoring any server certificate anyway).
% bash
$ diff -u \
<(openssl ciphers -v ALL:@STRENGTH) \
<(openssl ciphers -v aNULL:-aNULL:ALL:@STRENGTH)
--- /dev/fd/63 2016-04-09 15:19:03.000000000 -0400
+++ /dev/fd/62 2016-04-09 15:19:03.000000000 -0400
@@ -1,3 +1,9 @@
+ADH-AES256-GCM-SHA384 TLSv1.2 Kx=DH Au=None Enc=AESGCM(256)
Mac=AEAD
+ADH-AES256-SHA256 TLSv1.2 Kx=DH Au=None Enc=AES(256)
Mac=SHA256
+ADH-CAMELLIA256-SHA256 TLSv1.2 Kx=DH Au=None Enc=Camellia(256)
Mac=SHA256
+AECDH-AES256-SHA SSLv3 Kx=ECDH Au=None Enc=AES(256) Mac=SHA1
+ADH-AES256-SHA SSLv3 Kx=DH Au=None Enc=AES(256) Mac=SHA1
+ADH-CAMELLIA256-SHA SSLv3 Kx=DH Au=None Enc=Camellia(256)
Mac=SHA1
ECDHE-ECDSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(256)
Mac=AEAD
ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(256)
Mac=AEAD
DHE-DSS-AES256-GCM-SHA384 TLSv1.2 Kx=DH Au=DSS Enc=AESGCM(256)
Mac=AEAD
@@ -9,7 +15,6 @@
ECDHE-ECDSA-AES256-CCM TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM(256)
Mac=AEAD
DHE-RSA-AES256-CCM8 TLSv1.2 Kx=DH Au=RSA Enc=AESCCM8(256)
Mac=AEAD
DHE-RSA-AES256-CCM TLSv1.2 Kx=DH Au=RSA Enc=AESCCM(256)
Mac=AEAD
-ADH-AES256-GCM-SHA384 TLSv1.2 Kx=DH Au=None Enc=AESGCM(256)
Mac=AEAD
ECDHE-ECDSA-AES256-SHA384 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AES(256)
Mac=SHA384
ECDHE-RSA-AES256-SHA384 TLSv1.2 Kx=ECDH Au=RSA Enc=AES(256)
Mac=SHA384
DHE-RSA-AES256-SHA256 TLSv1.2 Kx=DH Au=RSA Enc=AES(256)
Mac=SHA256
@@ -18,17 +23,12 @@
ECDHE-RSA-CAMELLIA256-SHA384 TLSv1.2 Kx=ECDH Au=RSA Enc=Camellia(256)
Mac=SHA384
DHE-RSA-CAMELLIA256-SHA256 TLSv1.2 Kx=DH Au=RSA Enc=Camellia(256)
Mac=SHA256
DHE-DSS-CAMELLIA256-SHA256 TLSv1.2 Kx=DH Au=DSS Enc=Camellia(256)
Mac=SHA256
-ADH-AES256-SHA256 TLSv1.2 Kx=DH Au=None Enc=AES(256)
Mac=SHA256
-ADH-CAMELLIA256-SHA256 TLSv1.2 Kx=DH Au=None Enc=Camellia(256)
Mac=SHA256
ECDHE-ECDSA-AES256-SHA SSLv3 Kx=ECDH Au=ECDSA Enc=AES(256) Mac=SHA1
ECDHE-RSA-AES256-SHA SSLv3 Kx=ECDH Au=RSA Enc=AES(256) Mac=SHA1
DHE-RSA-AES256-SHA SSLv3 Kx=DH Au=RSA Enc=AES(256) Mac=SHA1
DHE-DSS-AES256-SHA SSLv3 Kx=DH Au=DSS Enc=AES(256) Mac=SHA1
DHE-RSA-CAMELLIA256-SHA SSLv3 Kx=DH Au=RSA Enc=Camellia(256)
Mac=SHA1
DHE-DSS-CAMELLIA256-SHA SSLv3 Kx=DH Au=DSS Enc=Camellia(256)
Mac=SHA1
-AECDH-AES256-SHA SSLv3 Kx=ECDH Au=None Enc=AES(256) Mac=SHA1
-ADH-AES256-SHA SSLv3 Kx=DH Au=None Enc=AES(256) Mac=SHA1
-ADH-CAMELLIA256-SHA SSLv3 Kx=DH Au=None Enc=Camellia(256)
Mac=SHA1
RSA-PSK-AES256-GCM-SHA384 TLSv1.2 Kx=RSAPSK Au=RSA Enc=AESGCM(256)
Mac=AEAD
DHE-PSK-AES256-GCM-SHA384 TLSv1.2 Kx=DHEPSK Au=PSK Enc=AESGCM(256)
Mac=AEAD
RSA-PSK-CHACHA20-POLY1305 TLSv1.2 Kx=RSAPSK Au=RSA
Enc=CHACHA20/POLY1305(256) Mac=AEAD
@@ -62,6 +62,13 @@
PSK-AES256-CBC-SHA384 TLSv1 Kx=PSK Au=PSK Enc=AES(256) Mac=SHA384
PSK-AES256-CBC-SHA SSLv3 Kx=PSK Au=PSK Enc=AES(256) Mac=SHA1
PSK-CAMELLIA256-SHA384 TLSv1 Kx=PSK Au=PSK Enc=Camellia(256)
Mac=SHA384
+ADH-AES128-GCM-SHA256 TLSv1.2 Kx=DH Au=None Enc=AESGCM(128)
Mac=AEAD
+ADH-AES128-SHA256 TLSv1.2 Kx=DH Au=None Enc=AES(128)
Mac=SHA256
+ADH-CAMELLIA128-SHA256 TLSv1.2 Kx=DH Au=None Enc=Camellia(128)
Mac=SHA256
+AECDH-AES128-SHA SSLv3 Kx=ECDH Au=None Enc=AES(128) Mac=SHA1
+ADH-AES128-SHA SSLv3 Kx=DH Au=None Enc=AES(128) Mac=SHA1
+ADH-SEED-SHA SSLv3 Kx=DH Au=None Enc=SEED(128) Mac=SHA1
+ADH-CAMELLIA128-SHA SSLv3 Kx=DH Au=None Enc=Camellia(128)
Mac=SHA1
ECDHE-ECDSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(128)
Mac=AEAD
ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(128)
Mac=AEAD
DHE-DSS-AES128-GCM-SHA256 TLSv1.2 Kx=DH Au=DSS Enc=AESGCM(128)
Mac=AEAD
@@ -70,7 +77,6 @@
ECDHE-ECDSA-AES128-CCM TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM(128)
Mac=AEAD
DHE-RSA-AES128-CCM8 TLSv1.2 Kx=DH Au=RSA Enc=AESCCM8(128)
Mac=AEAD
DHE-RSA-AES128-CCM TLSv1.2 Kx=DH Au=RSA Enc=AESCCM(128)
Mac=AEAD
-ADH-AES128-GCM-SHA256 TLSv1.2 Kx=DH Au=None Enc=AESGCM(128)
Mac=AEAD
ECDHE-ECDSA-AES128-SHA256 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AES(128)
Mac=SHA256
ECDHE-RSA-AES128-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=AES(128)
Mac=SHA256
DHE-RSA-AES128-SHA256 TLSv1.2 Kx=DH Au=RSA Enc=AES(128)
Mac=SHA256
@@ -79,8 +85,6 @@
ECDHE-RSA-CAMELLIA128-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=Camellia(128)
Mac=SHA256
DHE-RSA-CAMELLIA128-SHA256 TLSv1.2 Kx=DH Au=RSA Enc=Camellia(128)
Mac=SHA256
DHE-DSS-CAMELLIA128-SHA256 TLSv1.2 Kx=DH Au=DSS Enc=Camellia(128)
Mac=SHA256
-ADH-AES128-SHA256 TLSv1.2 Kx=DH Au=None Enc=AES(128)
Mac=SHA256
-ADH-CAMELLIA128-SHA256 TLSv1.2 Kx=DH Au=None Enc=Camellia(128)
Mac=SHA256
ECDHE-ECDSA-AES128-SHA SSLv3 Kx=ECDH Au=ECDSA Enc=AES(128) Mac=SHA1
ECDHE-RSA-AES128-SHA SSLv3 Kx=ECDH Au=RSA Enc=AES(128) Mac=SHA1
DHE-RSA-AES128-SHA SSLv3 Kx=DH Au=RSA Enc=AES(128) Mac=SHA1
@@ -89,10 +93,6 @@
DHE-DSS-SEED-SHA SSLv3 Kx=DH Au=DSS Enc=SEED(128) Mac=SHA1
DHE-RSA-CAMELLIA128-SHA SSLv3 Kx=DH Au=RSA Enc=Camellia(128)
Mac=SHA1
DHE-DSS-CAMELLIA128-SHA SSLv3 Kx=DH Au=DSS Enc=Camellia(128)
Mac=SHA1
-AECDH-AES128-SHA SSLv3 Kx=ECDH Au=None Enc=AES(128) Mac=SHA1
-ADH-AES128-SHA SSLv3 Kx=DH Au=None Enc=AES(128) Mac=SHA1
-ADH-SEED-SHA SSLv3 Kx=DH Au=None Enc=SEED(128) Mac=SHA1
-ADH-CAMELLIA128-SHA SSLv3 Kx=DH Au=None Enc=Camellia(128)
Mac=SHA1
RSA-PSK-AES128-GCM-SHA256 TLSv1.2 Kx=RSAPSK Au=RSA Enc=AESGCM(128)
Mac=AEAD
DHE-PSK-AES128-GCM-SHA256 TLSv1.2 Kx=DHEPSK Au=PSK Enc=AESGCM(128)
Mac=AEAD
DHE-PSK-AES128-CCM8 TLSv1.2 Kx=DHEPSK Au=PSK Enc=AESCCM8(128)
Mac=AEAD
@@ -124,12 +124,12 @@
PSK-AES128-CBC-SHA256 TLSv1 Kx=PSK Au=PSK Enc=AES(128) Mac=SHA256
PSK-AES128-CBC-SHA SSLv3 Kx=PSK Au=PSK Enc=AES(128) Mac=SHA1
PSK-CAMELLIA128-SHA256 TLSv1 Kx=PSK Au=PSK Enc=Camellia(128)
Mac=SHA256
+AECDH-DES-CBC3-SHA SSLv3 Kx=ECDH Au=None Enc=3DES(168) Mac=SHA1
+ADH-DES-CBC3-SHA SSLv3 Kx=DH Au=None Enc=3DES(168) Mac=SHA1
ECDHE-ECDSA-DES-CBC3-SHA SSLv3 Kx=ECDH Au=ECDSA Enc=3DES(168) Mac=SHA1
ECDHE-RSA-DES-CBC3-SHA SSLv3 Kx=ECDH Au=RSA Enc=3DES(168) Mac=SHA1
DHE-RSA-DES-CBC3-SHA SSLv3 Kx=DH Au=RSA Enc=3DES(168) Mac=SHA1
DHE-DSS-DES-CBC3-SHA SSLv3 Kx=DH Au=DSS Enc=3DES(168) Mac=SHA1
-AECDH-DES-CBC3-SHA SSLv3 Kx=ECDH Au=None Enc=3DES(168) Mac=SHA1
-ADH-DES-CBC3-SHA SSLv3 Kx=DH Au=None Enc=3DES(168) Mac=SHA1
ECDHE-PSK-3DES-EDE-CBC-SHA SSLv3 Kx=ECDHEPSK Au=PSK Enc=3DES(168) Mac=SHA1
SRP-DSS-3DES-EDE-CBC-SHA SSLv3 Kx=SRP Au=DSS Enc=3DES(168) Mac=SHA1
SRP-RSA-3DES-EDE-CBC-SHA SSLv3 Kx=SRP Au=RSA Enc=3DES(168) Mac=SHA1
--
Viktor.
