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-rw-r--r--doc/apps/ciphers.pod59
1 files changed, 34 insertions, 25 deletions
diff --git a/doc/apps/ciphers.pod b/doc/apps/ciphers.pod
index 1c26e3b3da36..9643b4d48ca8 100644
--- a/doc/apps/ciphers.pod
+++ b/doc/apps/ciphers.pod
@@ -38,25 +38,21 @@ SSL v2 and for SSL v3/TLS v1.
Like B<-v>, but include cipher suite codes in output (hex format).
-=item B<-ssl3>
+=item B<-ssl3>, B<-tls1>
-only include SSL v3 ciphers.
+This lists ciphers compatible with any of SSLv3, TLSv1, TLSv1.1 or TLSv1.2.
=item B<-ssl2>
-only include SSL v2 ciphers.
-
-=item B<-tls1>
-
-only include TLS v1 ciphers.
+Only include SSLv2 ciphers.
=item B<-h>, B<-?>
-print a brief usage message.
+Print a brief usage message.
=item B<cipherlist>
-a cipher list to convert to a cipher preference list. If it is not included
+A cipher list to convert to a cipher preference list. If it is not included
then the default cipher list will be used. The format is described below.
=back
@@ -109,9 +105,10 @@ The following is a list of all permitted cipher strings and their meanings.
=item B<DEFAULT>
-the default cipher list. This is determined at compile time and
-is normally B<ALL:!EXPORT:!aNULL:!eNULL:!SSLv2>. This must be the firstcipher string
-specified.
+The default cipher list.
+This is determined at compile time and is normally
+B<ALL:!EXPORT:!aNULL:!eNULL:!SSLv2>.
+When used, this must be the first cipherstring specified.
=item B<COMPLEMENTOFDEFAULT>
@@ -139,34 +136,46 @@ than 128 bits, and some cipher suites with 128-bit keys.
=item B<LOW>
-"low" encryption cipher suites, currently those using 64 or 56 bit encryption algorithms
-but excluding export cipher suites.
+Low strength encryption cipher suites, currently those using 64 or 56 bit
+encryption algorithms but excluding export cipher suites.
+As of OpenSSL 1.0.2g, these are disabled in default builds.
=item B<EXP>, B<EXPORT>
-export encryption algorithms. Including 40 and 56 bits algorithms.
+Export strength encryption algorithms. Including 40 and 56 bits algorithms.
+As of OpenSSL 1.0.2g, these are disabled in default builds.
=item B<EXPORT40>
-40 bit export encryption algorithms
+40-bit export encryption algorithms
+As of OpenSSL 1.0.2g, these are disabled in default builds.
=item B<EXPORT56>
-56 bit export encryption algorithms. In OpenSSL 0.9.8c and later the set of
+56-bit export encryption algorithms. In OpenSSL 0.9.8c and later the set of
56 bit export ciphers is empty unless OpenSSL has been explicitly configured
with support for experimental ciphers.
+As of OpenSSL 1.0.2g, these are disabled in default builds.
=item B<eNULL>, B<NULL>
-the "NULL" ciphers that is those offering no encryption. Because these offer no
-encryption at all and are a security risk they are disabled unless explicitly
-included.
+The "NULL" ciphers that is those offering no encryption. Because these offer no
+encryption at all and are a security risk they are not enabled via either the
+B<DEFAULT> or B<ALL> cipher strings.
+Be careful when building cipherlists out of lower-level primitives such as
+B<kRSA> or B<aECDSA> as these do overlap with the B<eNULL> ciphers.
+When in doubt, include B<!eNULL> in your cipherlist.
=item B<aNULL>
-the cipher suites offering no authentication. This is currently the anonymous
+The cipher suites offering no authentication. This is currently the anonymous
DH algorithms and anonymous ECDH algorithms. These cipher suites are vulnerable
to a "man in the middle" attack and so their use is normally discouraged.
+These are excluded from the B<DEFAULT> ciphers, but included in the B<ALL>
+ciphers.
+Be careful when building cipherlists out of lower-level primitives such as
+B<kDHE> or B<AES> as these do overlap with the B<aNULL> ciphers.
+When in doubt, include B<!aNULL> in your cipherlist.
=item B<kRSA>, B<RSA>
@@ -582,11 +591,11 @@ Note: these ciphers can also be used in SSL v3.
=head2 Deprecated SSL v2.0 cipher suites.
SSL_CK_RC4_128_WITH_MD5 RC4-MD5
- SSL_CK_RC4_128_EXPORT40_WITH_MD5 EXP-RC4-MD5
- SSL_CK_RC2_128_CBC_WITH_MD5 RC2-MD5
- SSL_CK_RC2_128_CBC_EXPORT40_WITH_MD5 EXP-RC2-MD5
+ SSL_CK_RC4_128_EXPORT40_WITH_MD5 Not implemented.
+ SSL_CK_RC2_128_CBC_WITH_MD5 RC2-CBC-MD5
+ SSL_CK_RC2_128_CBC_EXPORT40_WITH_MD5 Not implemented.
SSL_CK_IDEA_128_CBC_WITH_MD5 IDEA-CBC-MD5
- SSL_CK_DES_64_CBC_WITH_MD5 DES-CBC-MD5
+ SSL_CK_DES_64_CBC_WITH_MD5 Not implemented.
SSL_CK_DES_192_EDE3_CBC_WITH_MD5 DES-CBC3-MD5
=head1 NOTES