| =pod |
| |
| =head1 NAME |
| |
| ciphers - SSL cipher display and cipher list tool. |
| |
| =head1 SYNOPSIS |
| |
| B<openssl> B<ciphers> |
| [B<-v>] |
| [B<-ssl2>] |
| [B<-ssl3>] |
| [B<-tls1>] |
| [B<cipherlist>] |
| |
| =head1 DESCRIPTION |
| |
| The B<cipherlist> command converts OpenSSL cipher lists into ordered |
| SSL cipher preference lists. It can be used as a test tool to determine |
| the appropriate cipherlist. |
| |
| =head1 COMMAND OPTIONS |
| |
| =over 4 |
| |
| =item B<-v> |
| |
| verbose option. List ciphers with a complete description of |
| protocol version (SSLv2 or SSLv3; the latter includes TLS), key exchange, |
| authentication, encryption and mac algorithms used along with any key size |
| restrictions and whether the algorithm is classed as an "export" cipher. |
| Note that without the B<-v> option, ciphers may seem to appear twice |
| in a cipher list; this is when similar ciphers are available for |
| SSL v2 and for SSL v3/TLS v1. |
| |
| =item B<-ssl3> |
| |
| only include SSL v3 ciphers. |
| |
| =item B<-ssl2> |
| |
| only include SSL v2 ciphers. |
| |
| =item B<-tls1> |
| |
| only include TLS v1 ciphers. |
| |
| =item B<-h>, B<-?> |
| |
| print a brief usage message. |
| |
| =item B<cipherlist> |
| |
| 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 |
| |
| =head1 CIPHER LIST FORMAT |
| |
| The cipher list consists of one or more I<cipher strings> separated by colons. |
| Commas or spaces are also acceptable separators but colons are normally used. |
| |
| The actual cipher string can take several different forms. |
| |
| It can consist of a single cipher suite such as B<RC4-SHA>. |
| |
| It can represent a list of cipher suites containing a certain algorithm, or |
| cipher suites of a certain type. For example B<SHA1> represents all ciphers |
| suites using the digest algorithm SHA1 and B<SSLv3> represents all SSL v3 |
| algorithms. |
| |
| Lists of cipher suites can be combined in a single cipher string using the |
| B<+> character. This is used as a logical B<and> operation. For example |
| B<SHA1+DES> represents all cipher suites containing the SHA1 B<and> the DES |
| algorithms. |
| |
| Each cipher string can be optionally preceded by the characters B<!>, |
| B<-> or B<+>. |
| |
| If B<!> is used then the ciphers are permanently deleted from the list. |
| The ciphers deleted can never reappear in the list even if they are |
| explicitly stated. |
| |
| If B<-> is used then the ciphers are deleted from the list, but some or |
| all of the ciphers can be added again by later options. |
| |
| If B<+> is used then the ciphers are moved to the end of the list. This |
| option doesn't add any new ciphers it just moves matching existing ones. |
| |
| If none of these characters is present then the string is just interpreted |
| as a list of ciphers to be appended to the current preference list. If the |
| list includes any ciphers already present they will be ignored: that is they |
| will not moved to the end of the list. |
| |
| Additionally the cipher string B<@STRENGTH> can be used at any point to sort |
| the current cipher list in order of encryption algorithm key length. |
| |
| =head1 CIPHER STRINGS |
| |
| The following is a list of all permitted cipher strings and their meanings. |
| |
| =over 4 |
| |
| =item B<DEFAULT> |
| |
| 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<ALL> |
| |
| all ciphers suites except the B<eNULL> ciphers which must be explicitly enabled. |
| |
| =item B<HIGH> |
| |
| "high" encryption cipher suites. This currently means those with key lengths larger |
| than 128 bits. |
| |
| =item B<MEDIUM> |
| |
| "medium" encryption cipher suites, currently those using 128 bit encryption. |
| |
| =item B<LOW> |
| |
| "low" encryption cipher suites, currently those using 64 or 56 bit encryption algorithms |
| but excluding export cipher suites. |
| |
| =item B<EXP>, B<EXPORT> |
| |
| export encryption algorithms. Including 40 and 56 bits algorithms. |
| |
| =item B<EXPORT40> |
| |
| 40 bit export encryption algorithms |
| |
| =item B<EXPORT56> |
| |
| 56 bit export encryption algorithms. |
| |
| =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. |
| |
| =item B<aNULL> |
| |
| the cipher suites offering no authentication. This is currently the anonymous |
| DH algorithms. These cipher suites are vulnerable to a "man in the middle" |
| attack and so their use is normally discouraged. |
| |
| =item B<kRSA>, B<RSA> |
| |
| cipher suites using RSA key exchange. |
| |
| =item B<kEDH> |
| |
| cipher suites using ephemeral DH key agreement. |
| |
| =item B<kDHr>, B<kDHd> |
| |
| cipher suites using DH key agreement and DH certificates signed by CAs with RSA |
| and DSS keys respectively. Not implemented. |
| |
| =item B<aRSA> |
| |
| cipher suites using RSA authentication, i.e. the certificates carry RSA keys. |
| |
| =item B<aDSS>, B<DSS> |
| |
| cipher suites using DSS authentication, i.e. the certificates carry DSS keys. |
| |
| =item B<aDH> |
| |
| cipher suites effectively using DH authentication, i.e. the certificates carry |
| DH keys. Not implemented. |
| |
| =item B<kFZA>, B<aFZA>, B<eFZA>, B<FZA> |
| |
| ciphers suites using FORTEZZA key exchange, authentication, encryption or all |
| FORTEZZA algorithms. Not implemented. |
| |
| =item B<TLSv1>, B<SSLv3>, B<SSLv2> |
| |
| TLS v1.0, SSL v3.0 or SSL v2.0 cipher suites respectively. |
| |
| =item B<DH> |
| |
| cipher suites using DH, including anonymous DH. |
| |
| =item B<ADH> |
| |
| anonymous DH cipher suites. |
| |
| =item B<3DES> |
| |
| cipher suites using triple DES. |
| |
| =item B<DES> |
| |
| cipher suites using DES (not triple DES). |
| |
| =item B<RC4> |
| |
| cipher suites using RC4. |
| |
| =item B<RC2> |
| |
| cipher suites using RC2. |
| |
| =item B<IDEA> |
| |
| cipher suites using IDEA. |
| |
| =item B<MD5> |
| |
| cipher suites using MD5. |
| |
| =item B<SHA1>, B<SHA> |
| |
| cipher suites using SHA1. |
| |
| =back |
| |
| =head1 CIPHER SUITE NAMES |
| |
| The following lists give the SSL or TLS cipher suites names from the |
| relevant specification and their OpenSSL equivalents. |
| |
| =head2 SSL v3.0 cipher suites. |
| |
| SSL_RSA_WITH_NULL_MD5 NULL-MD5 |
| SSL_RSA_WITH_NULL_SHA NULL-SHA |
| SSL_RSA_EXPORT_WITH_RC4_40_MD5 EXP-RC4-MD5 |
| SSL_RSA_WITH_RC4_128_MD5 RC4-MD5 |
| SSL_RSA_WITH_RC4_128_SHA RC4-SHA |
| SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5 EXP-RC2-CBC-MD5 |
| SSL_RSA_WITH_IDEA_CBC_SHA IDEA-CBC-SHA |
| SSL_RSA_EXPORT_WITH_DES40_CBC_SHA EXP-DES-CBC-SHA |
| SSL_RSA_WITH_DES_CBC_SHA DES-CBC-SHA |
| SSL_RSA_WITH_3DES_EDE_CBC_SHA DES-CBC3-SHA |
| |
| SSL_DH_DSS_EXPORT_WITH_DES40_CBC_SHA Not implemented. |
| SSL_DH_DSS_WITH_DES_CBC_SHA Not implemented. |
| SSL_DH_DSS_WITH_3DES_EDE_CBC_SHA Not implemented. |
| SSL_DH_RSA_EXPORT_WITH_DES40_CBC_SHA Not implemented. |
| SSL_DH_RSA_WITH_DES_CBC_SHA Not implemented. |
| SSL_DH_RSA_WITH_3DES_EDE_CBC_SHA Not implemented. |
| SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA EXP-EDH-DSS-DES-CBC-SHA |
| SSL_DHE_DSS_WITH_DES_CBC_SHA EDH-DSS-CBC-SHA |
| SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA EDH-DSS-DES-CBC3-SHA |
| SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA EXP-EDH-RSA-DES-CBC-SHA |
| SSL_DHE_RSA_WITH_DES_CBC_SHA EDH-RSA-DES-CBC-SHA |
| SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA EDH-RSA-DES-CBC3-SHA |
| |
| SSL_DH_anon_EXPORT_WITH_RC4_40_MD5 EXP-ADH-RC4-MD5 |
| SSL_DH_anon_WITH_RC4_128_MD5 ADH-RC4-MD5 |
| SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA EXP-ADH-DES-CBC-SHA |
| SSL_DH_anon_WITH_DES_CBC_SHA ADH-DES-CBC-SHA |
| SSL_DH_anon_WITH_3DES_EDE_CBC_SHA ADH-DES-CBC3-SHA |
| |
| SSL_FORTEZZA_KEA_WITH_NULL_SHA Not implemented. |
| SSL_FORTEZZA_KEA_WITH_FORTEZZA_CBC_SHA Not implemented. |
| SSL_FORTEZZA_KEA_WITH_RC4_128_SHA Not implemented. |
| |
| =head2 TLS v1.0 cipher suites. |
| |
| TLS_RSA_WITH_NULL_MD5 NULL-MD5 |
| TLS_RSA_WITH_NULL_SHA NULL-SHA |
| TLS_RSA_EXPORT_WITH_RC4_40_MD5 EXP-RC4-MD5 |
| TLS_RSA_WITH_RC4_128_MD5 RC4-MD5 |
| TLS_RSA_WITH_RC4_128_SHA RC4-SHA |
| TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5 EXP-RC2-CBC-MD5 |
| TLS_RSA_WITH_IDEA_CBC_SHA IDEA-CBC-SHA |
| TLS_RSA_EXPORT_WITH_DES40_CBC_SHA EXP-DES-CBC-SHA |
| TLS_RSA_WITH_DES_CBC_SHA DES-CBC-SHA |
| TLS_RSA_WITH_3DES_EDE_CBC_SHA DES-CBC3-SHA |
| |
| TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA Not implemented. |
| TLS_DH_DSS_WITH_DES_CBC_SHA Not implemented. |
| TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA Not implemented. |
| TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA Not implemented. |
| TLS_DH_RSA_WITH_DES_CBC_SHA Not implemented. |
| TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA Not implemented. |
| TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA EXP-EDH-DSS-DES-CBC-SHA |
| TLS_DHE_DSS_WITH_DES_CBC_SHA EDH-DSS-CBC-SHA |
| TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA EDH-DSS-DES-CBC3-SHA |
| TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA EXP-EDH-RSA-DES-CBC-SHA |
| TLS_DHE_RSA_WITH_DES_CBC_SHA EDH-RSA-DES-CBC-SHA |
| TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA EDH-RSA-DES-CBC3-SHA |
| |
| TLS_DH_anon_EXPORT_WITH_RC4_40_MD5 EXP-ADH-RC4-MD5 |
| TLS_DH_anon_WITH_RC4_128_MD5 ADH-RC4-MD5 |
| TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA EXP-ADH-DES-CBC-SHA |
| TLS_DH_anon_WITH_DES_CBC_SHA ADH-DES-CBC-SHA |
| TLS_DH_anon_WITH_3DES_EDE_CBC_SHA ADH-DES-CBC3-SHA |
| |
| =head2 Additional Export 1024 and other cipher suites |
| |
| Note: these ciphers can also be used in SSL v3. |
| |
| TLS_RSA_EXPORT1024_WITH_DES_CBC_SHA EXP1024-DES-CBC-SHA |
| TLS_RSA_EXPORT1024_WITH_RC4_56_SHA EXP1024-RC4-SHA |
| TLS_DHE_DSS_EXPORT1024_WITH_DES_CBC_SHA EXP1024-DHE-DSS-DES-CBC-SHA |
| TLS_DHE_DSS_EXPORT1024_WITH_RC4_56_SHA EXP1024-DHE-DSS-RC4-SHA |
| TLS_DHE_DSS_WITH_RC4_128_SHA DHE-DSS-RC4-SHA |
| |
| =head2 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_IDEA_128_CBC_WITH_MD5 IDEA-CBC-MD5 |
| SSL_CK_DES_64_CBC_WITH_MD5 DES-CBC-MD5 |
| SSL_CK_DES_192_EDE3_CBC_WITH_MD5 DES-CBC3-MD5 |
| |
| =head1 NOTES |
| |
| The non-ephemeral DH modes are currently unimplemented in OpenSSL |
| because there is no support for DH certificates. |
| |
| Some compiled versions of OpenSSL may not include all the ciphers |
| listed here because some ciphers were excluded at compile time. |
| |
| =head1 EXAMPLES |
| |
| Verbose listing of all OpenSSL ciphers including NULL ciphers: |
| |
| openssl ciphers -v 'ALL:eNULL' |
| |
| Include all ciphers except NULL and anonymous DH then sort by |
| strength: |
| |
| openssl ciphers -v 'ALL:!ADH:@STRENGTH' |
| |
| Include only 3DES ciphers and then place RSA ciphers last: |
| |
| openssl ciphers -v '3DES:+RSA' |
| |
| =head1 SEE ALSO |
| |
| L<s_client(1)|s_client(1)>, L<s_server(1)|s_server(1)>, L<ssl(3)|ssl(3)> |
| |
| =cut |
