freebsd-dev/crypto/openssl/doc/ssl/SSL_CIPHER_get_name.pod
2001-05-20 03:07:21 +00:00

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=pod
=head1 NAME
SSL_CIPHER_get_name, SSL_CIPHER_get_bits, SSL_CIPHER_get_version, SSL_CIPHER_description - get SSL_CIPHER properties
=head1 SYNOPSIS
#include <openssl/ssl.h>
const char *SSL_CIPHER_get_name(SSL_CIPHER *cipher);
int SSL_CIPHER_get_bits(SSL_CIPHER *cipher, int *alg_bits);
char *SSL_CIPHER_get_version(SSL_CIPHER *cipher);
char *SSL_CIPHER_description(SSL_CIPHER *cipher, char *buf, int size);
=head1 DESCRIPTION
SSL_CIPHER_get_name() returns a pointer to the name of B<cipher>. If the
argument is the NULL pointer, a pointer to the constant value "NONE" is
returned.
SSL_CIPHER_get_bits() returns the number of secret bits used for B<cipher>. If
B<alg_bits> is not NULL, it contains the number of bits processed by the
chosen algorithm. If B<cipher> is NULL, 0 is returned.
SSL_CIPHER_get_version() returns the protocol version for B<cipher>, currently
"SSLv2", "SSLv3", or "TLSv1". If B<cipher> is NULL, "(NONE)" is returned.
SSL_CIPHER_description() returns a textual description of the cipher used
into the buffer B<buf> of length B<len> provided. B<len> must be at least
128 bytes, otherwise a pointer to the the string "Buffer too small" is
returned. If B<buf> is NULL, a buffer of 128 bytes is allocated using
OPENSSL_malloc(). If the allocation fails, a pointer to the string
"OPENSSL_malloc Error" is returned.
=head1 NOTES
The number of bits processed can be different from the secret bits. An
export cipher like e.g. EXP-RC4-MD5 has only 40 secret bits. The algorithm
does use the full 128 bits (which would be returned for B<alg_bits>), of
which however 88bits are fixed. The search space is hence only 40 bits.
The string returned by SSL_CIPHER_description() in case of success consists
of cleartext information separated by one or more blanks in the following
sequence:
=over 4
=item <ciphername>
Textual representation of the cipher name.
=item <protocol version>
Protocol version: B<SSLv2>, B<SSLv3>. The TLSv1 ciphers are flagged with SSLv3.
=item Kx=<key exchange>
Key exchange method: B<RSA> (for export ciphers as B<RSA(512)> or
B<RSA(1024)>), B<DH> (for export ciphers as B<DH(512)> or B<DH(1024)>),
B<DH/RSA>, B<DH/DSS>, B<Fortezza>.
=item Au=<authentication>
Authentication method: B<RSA>, B<DSS>, B<DH>, B<None>. None is the
representation of anonymous ciphers.
=item Enc=<symmetric encryption method>
Encryption method with number of secret bits: B<DES(40)>, B<DES(56)>,
B<3DES(168)>, B<RC4(40)>, B<RC4(56)>, B<RC4(64)>, B<RC4(128)>,
B<RC2(40)>, B<RC2(56)>, B<RC2(128)>, B<IDEA(128)>, B<Fortezza>, B<None>.
=item Mac=<message authentication code>
Message digest: B<MD5>, B<SHA1>.
=item <export flag>
If the cipher is flagged exportable with respect to old US crypto
regulations, the word "B<export>" is printed.
=back
=head1 EXAMPLES
Some examples for the output of SSL_CIPHER_description():
EDH-RSA-DES-CBC3-SHA SSLv3 Kx=DH Au=RSA Enc=3DES(168) Mac=SHA1
EDH-DSS-DES-CBC3-SHA SSLv3 Kx=DH Au=DSS Enc=3DES(168) Mac=SHA1
RC4-MD5 SSLv3 Kx=RSA Au=RSA Enc=RC4(128) Mac=MD5
EXP-RC4-MD5 SSLv3 Kx=RSA(512) Au=RSA Enc=RC4(40) Mac=MD5 export
=head1 BUGS
If SSL_CIPHER_description() is called with B<cipher> being NULL, the
library crashes.
If SSL_CIPHER_description() cannot handle a built-in cipher, the according
description of the cipher property is B<unknown>. This case should not
occur.
=head1 RETURN VALUES
See DESCRIPTION
=head1 SEE ALSO
L<ssl(3)|ssl(3)>, L<SSL_get_current_cipher(3)|SSL_get_current_cipher(3)>,
L<SSL_get_ciphers(3)|SSL_get_ciphers(3)>, L<ciphers(1)|ciphers(1)>
=cut