New cipher selection options COMPLEMENTOFALL and COMPLEMENTOFDEFAULT.

Submitted by:
Reviewed by:
PR: 127

CHANGES

@@ -101,6 +101,11 @@
  
  Changes between 0.9.6e and 0.9.7  [XX xxx 2002]
 
+  *) Add cipher selection rules COMPLEMENTOFALL and COMPLENENTOFDEFAULT
+     to allow version independent disabling of normally unselected ciphers,
+     which may be activated as a side-effect of selecting a single cipher.
+     [Lutz Jaenicke, Bodo Moeller]
+
   *) Add appropriate support for separate platform-dependent build
      directories.  The recommended way to make a platform-dependent
      build directory is the following (tested on Linux), maybe with

doc/apps/ciphers.pod

@@ -108,10 +108,20 @@ the default cipher list. This is determined at compile time and is normally
 B<ALL:!ADH:RC4+RSA:+SSLv2:@STRENGTH>. This must be the first cipher string
 specified.
 
+=item B<COMPLEMENTOFDEFAULT>
+
+the ciphers not enabled by default, currently being B<ADH>. This rule does not
+cover B<eNULL>, which is not included by B<ALL> and is therefore be handled by
+B<COMPLENETOFALL>.
+
 =item B<ALL>
 
 all ciphers suites except the B<eNULL> ciphers which must be explicitly enabled.
 
+=item B<COMPLEMENTOFALL>
+
+the cipher suites not enabled by B<ALL>, currently being B<eNULL>.
+
 =item B<HIGH>
 
 "high" encryption cipher suites. This currently means those with key lengths larger
@@ -339,8 +349,22 @@ Include only 3DES ciphers and then place RSA ciphers last:
 
  openssl ciphers -v '3DES:+RSA'
 
+Include all RC4 ciphers but leave out those without authentication:
+
+ openssl ciphers -v 'RC4:!COMPLEMENTOFDEFAULT'
+
+Include all chiphers with RSA authentication but leave out ciphers without
+encryption.
+
+ openssl ciphers -v 'RSA:!COMPLEMENTOFALL'
+
 =head1 SEE ALSO
 
 L<s_client(1)|s_client(1)>, L<s_server(1)|s_server(1)>, L<ssl(3)|ssl(3)>
 
+=head1 HISTORY
+
+The B<COMPLENTOFALL> and B<COMPLEMENTOFDEFAULT> selection options were
+added in version 0.9.7.
+
 =cut

ssl/ssl.h

@@ -266,6 +266,23 @@ extern "C" {
 #define SSL_TXT_TLSV1		"TLSv1"
 #define SSL_TXT_ALL		"ALL"
 
+/*
+ * COMPLEMENTOF* definitions. These identifiers are used to (de-select)
+ * ciphers normally not being used.
+ * Example: "RC4" will activate all ciphers using RC4 including ciphers
+ * without authentication, which would normally disabled by DEFAULT (due
+ * the "!ADH" being part of default). Therefore "RC4:!COMPLEMENTOFDEFAULT"
+ * will make sure that it is also disabled in the specific selection.
+ * COMPLEMENTOF* identifiers are portable between version, as adjustments
+ * to the default cipher setup will also be included here.
+ *
+ * COMPLEMENTOFDEFAULT does not experience the same special treatment that
+ * DEFAULT gets, as only selection is being done and no sorting as needed
+ * for DEFAULT.
+ */
+#define SSL_TXT_CMPALL		"COMPLEMENTOFALL"
+#define SSL_TXT_CMPDEF		"COMPLEMENTOFDEFAULT"
+
 /* The following cipher list is used by default.
  * It also is substituted when an application-defined cipher list string
  * starts with 'DEFAULT'. */

ssl/ssl_ciph.c

@@ -102,6 +102,8 @@ typedef struct cipher_order_st
 static const SSL_CIPHER cipher_aliases[]={
 	/* Don't include eNULL unless specifically enabled. */
 	{0,SSL_TXT_ALL, 0,SSL_ALL & ~SSL_eNULL, SSL_ALL ,0,0,0,SSL_ALL,SSL_ALL}, /* must be first */
+        {0,SSL_TXT_CMPALL,0,SSL_eNULL,0,0,0,0,SSL_ENC_MASK,0},  /* COMPLEMENT OF ALL */
+	{0,SSL_TXT_CMPDEF,0,SSL_ADH, 0,0,0,0,SSL_AUTH_MASK,0},
         {0,SSL_TXT_kKRB5,0,SSL_kKRB5,0,0,0,0,SSL_MKEY_MASK,0},  /* VRS Kerberos5 */
 	{0,SSL_TXT_kRSA,0,SSL_kRSA,  0,0,0,0,SSL_MKEY_MASK,0},
 	{0,SSL_TXT_kDHr,0,SSL_kDHr,  0,0,0,0,SSL_MKEY_MASK,0},