1=pod
2
3=head1 NAME
4
5SSL_CIPHER_get_name, SSL_CIPHER_get_bits, SSL_CIPHER_get_version, SSL_CIPHER_description - get SSL_CIPHER properties
6
7=head1 SYNOPSIS
8
9 #include <openssl/ssl.h>
10
11 const char *SSL_CIPHER_get_name(const SSL_CIPHER *cipher);
12 int SSL_CIPHER_get_bits(const SSL_CIPHER *cipher, int *alg_bits);
13 char *SSL_CIPHER_get_version(const SSL_CIPHER *cipher);
14 char *SSL_CIPHER_description(const SSL_CIPHER *cipher, char *buf, int size);
15
16=head1 DESCRIPTION
17
18SSL_CIPHER_get_name() returns a pointer to the name of B<cipher>. If the
19argument is the NULL pointer, a pointer to the constant value "NONE" is
20returned.
21
22SSL_CIPHER_get_bits() returns the number of secret bits used for B<cipher>. If
23B<alg_bits> is not NULL, it contains the number of bits processed by the
24chosen algorithm. If B<cipher> is NULL, 0 is returned.
25
26SSL_CIPHER_get_version() returns string which indicates the SSL/TLS protocol
27version that first defined the cipher.
28This is currently B<SSLv2> or B<TLSv1/SSLv3>.
29In some cases it should possibly return "TLSv1.2" but does not;
30use SSL_CIPHER_description() instead.
31If B<cipher> is NULL, "(NONE)" is returned.
32
33SSL_CIPHER_description() returns a textual description of the cipher used
34into the buffer B<buf> of length B<len> provided. B<len> must be at least
35128 bytes, otherwise a pointer to the string "Buffer too small" is
36returned. If B<buf> is NULL, a buffer of 128 bytes is allocated using
37OPENSSL_malloc(). If the allocation fails, a pointer to the string
38"OPENSSL_malloc Error" is returned.
39
40=head1 NOTES
41
42The number of bits processed can be different from the secret bits. An
43export cipher like e.g. EXP-RC4-MD5 has only 40 secret bits. The algorithm
44does use the full 128 bits (which would be returned for B<alg_bits>), of
45which however 88bits are fixed. The search space is hence only 40 bits.
46
47The string returned by SSL_CIPHER_description() in case of success consists
48of cleartext information separated by one or more blanks in the following
49sequence:
50
51=over 4
52
53=item <ciphername>
54
55Textual representation of the cipher name.
56
57=item <protocol version>
58
59Protocol version: B<SSLv2>, B<SSLv3>, B<TLSv1.2>. The TLSv1.0 ciphers are
60flagged with SSLv3. No new ciphers were added by TLSv1.1.
61
62=item Kx=<key exchange>
63
64Key exchange method: B<RSA> (for export ciphers as B<RSA(512)> or
65B<RSA(1024)>), B<DH> (for export ciphers as B<DH(512)> or B<DH(1024)>),
66B<DH/RSA>, B<DH/DSS>, B<Fortezza>.
67
68=item Au=<authentication>
69
70Authentication method: B<RSA>, B<DSS>, B<DH>, B<None>. None is the
71representation of anonymous ciphers.
72
73=item Enc=<symmetric encryption method>
74
75Encryption method with number of secret bits: B<DES(40)>, B<DES(56)>,
76B<3DES(168)>, B<RC4(40)>, B<RC4(56)>, B<RC4(64)>, B<RC4(128)>,
77B<RC2(40)>, B<RC2(56)>, B<RC2(128)>, B<IDEA(128)>, B<Fortezza>, B<None>.
78
79=item Mac=<message authentication code>
80
81Message digest: B<MD5>, B<SHA1>.
82
83=item <export flag>
84
85If the cipher is flagged exportable with respect to old US crypto
86regulations, the word "B<export>" is printed.
87
88=back
89
90=head1 EXAMPLES
91
92Some examples for the output of SSL_CIPHER_description():
93
94 EDH-RSA-DES-CBC3-SHA    SSLv3 Kx=DH       Au=RSA  Enc=3DES(168) Mac=SHA1
95 EDH-DSS-DES-CBC3-SHA    SSLv3 Kx=DH       Au=DSS  Enc=3DES(168) Mac=SHA1
96 RC4-MD5                 SSLv3 Kx=RSA      Au=RSA  Enc=RC4(128)  Mac=MD5
97 EXP-RC4-MD5             SSLv3 Kx=RSA(512) Au=RSA  Enc=RC4(40)   Mac=MD5  export
98
99A comp[lete list can be retrieved by invoking the following command:
100
101 openssl ciphers -v ALL
102
103=head1 BUGS
104
105If SSL_CIPHER_description() is called with B<cipher> being NULL, the
106library crashes.
107
108If SSL_CIPHER_description() cannot handle a built-in cipher, the according
109description of the cipher property is B<unknown>. This case should not
110occur.
111
112The standard terminology for ephemeral Diffie-Hellman schemes is DHE
113(finite field) or ECDHE (elliptic curve).  This version of OpenSSL
114idiosyncratically reports these schemes as EDH and EECDH, even though
115it also accepts the standard terminology.
116
117It is recommended to use the standard terminology (DHE and ECDHE)
118during configuration (e.g. via SSL_CTX_set_cipher_list) for clarity of
119configuration.  OpenSSL versions after 1.0.2 will report the standard
120terms via SSL_CIPHER_get_name and SSL_CIPHER_description.
121
122=head1 RETURN VALUES
123
124See DESCRIPTION
125
126=head1 SEE ALSO
127
128L<ssl(3)|ssl(3)>, L<SSL_get_current_cipher(3)|SSL_get_current_cipher(3)>,
129L<SSL_get_ciphers(3)|SSL_get_ciphers(3)>, L<ciphers(1)|ciphers(1)>,
130L<SSL_CTX_set_cipher_list(3)|SSL_CTX_set_cipher_list(3)>
131
132=cut
133