.\"	$OpenBSD: SSL_CIPHER_get_name.3,v 1.3 2017/07/05 11:43:09 schwarze Exp $
.\"	OpenSSL 45f55f6a Nov 30 15:35:22 2014 +0100
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.Dd $Mdocdate: July 5 2017 $
.Dt SSL_CIPHER_GET_NAME 3
.Os
.Sh NAME
.Nm SSL_CIPHER_get_name ,
.Nm SSL_CIPHER_get_bits ,
.Nm SSL_CIPHER_get_version ,
.Nm SSL_CIPHER_description
.Nd get SSL_CIPHER properties
.Sh SYNOPSIS
.In openssl/ssl.h
.Ft const char *
.Fn SSL_CIPHER_get_name "const SSL_CIPHER *cipher"
.Ft int
.Fn SSL_CIPHER_get_bits "const SSL_CIPHER *cipher" "int *alg_bits"
.Ft char *
.Fn SSL_CIPHER_get_version "const SSL_CIPHER *cipher"
.Ft char *
.Fn SSL_CIPHER_description "const SSL_CIPHER *cipher" "char *buf" "int size"
.Sh DESCRIPTION
.Fn SSL_CIPHER_get_name
returns a pointer to the name of
.Fa cipher .
If the
.Fa cipher
is
.Dv NULL ,
it returns
.Qq (NONE) .
.Pp
.Fn SSL_CIPHER_get_bits
returns the number of secret bits used for
.Fa cipher .
If
.Fa alg_bits
is not
.Dv NULL ,
it contains the number of bits processed by the
chosen algorithm.
If
.Fa cipher
is
.Dv NULL ,
0 is returned.
.Pp
.Fn SSL_CIPHER_get_version
returns a string which indicates the SSL/TLS protocol version that first
defined the cipher.
This is currently
.Qq TLSv1/SSLv3 .
In some cases it should possibly return
.Qq TLSv1.2
but the function does not; use
.Fn SSL_CIPHER_description
instead.
If
.Fa cipher
is
.Dv NULL ,
.Qq (NONE)
is returned.
.Pp
.Fn SSL_CIPHER_description
returns a textual description of the cipher used into the buffer
.Fa buf
of length
.Fa len
provided.
If
.Fa buf
is
.Dv NULL ,
a buffer is allocated using
.Xr asprintf 3 ;
that buffer should be freed using the
.Xr free 3
function.
If
.Fa len
is too small, or if
.Fa buf
is
.Dv NULL
and the allocation fails, a pointer to the string
.Qq Buffer too small
is returned.
.Pp
The string returned by
.Fn SSL_CIPHER_description
consists of several fields separated by whitespace:
.Bl -tag -width Ds
.It Aq Ar ciphername
Textual representation of the cipher name.
.It Aq Ar protocol version
Protocol version:
.Sy SSLv3
or
.Sy TLSv1.2 .
The TLSv1.0 ciphers are flagged with SSLv3.
No new ciphers were added by TLSv1.1.
.It Kx= Ns Aq Ar key exchange
Key exchange method:
.Sy DH ,
.Sy ECDH ,
.Sy GOST ,
or
.Sy RSA .
.It Au= Ns Aq Ar authentication
Authentication method:
.Sy DSS ,
.Sy ECDSA ,
.Sy GOST01 ,
.Sy RSA ,
or
.Sy None .
.Sy None
is the representation of anonymous ciphers.
.It Enc= Ns Aq Ar symmetric encryption method
Encryption method with number of secret bits:
.Sy DES(56) ,
.Sy 3DES(168) ,
.Sy RC4(64) ,
.Sy RC4(128) ,
.Sy IDEA(128) ,
.Sy AES(128) ,
.Sy AES(256) ,
.Sy AESCGM(128) ,
.Sy AESCGM(256) ,
.Sy Camellia(128) ,
.Sy Camellia(256) ,
.Sy ChaCha20-Poly1305 ,
.Sy ChaCha20-Poly1305-Old ,
.Sy GOST-28178-89-CNT ,
or
.Sy None .
.It Mac= Ns Aq Ar message authentication code
Message digest:
.Sy MD5 ,
.Sy SHA1 ,
.Sy SHA256 ,
.Sy SHA384 ,
.Sy AEAD ,
.Sy GOST94 ,
.Sy GOST89IMIT ,
.Sy STREEBOG256 ,
.Sy STREEBOG512 .
.El
.Sh EXAMPLES
An example for the output of
.Fn SSL_CIPHER_description :
.Bd -literal
ECDHE-RSA-AES256-GCM-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(256) Mac=AEAD
.Ed
.Pp
A complete list can be retrieved by invoking the following command:
.Pp
.Dl $ openssl ciphers -v ALL
.Sh SEE ALSO
.Xr openssl 1 ,
.Xr ssl 3 ,
.Xr SSL_get_ciphers 3 ,
.Xr SSL_get_current_cipher 3
.Sh BUGS
If
.Fn SSL_CIPHER_description
is called with
.Fa cipher
being
.Dv NULL ,
the library crashes.
.Pp
If
.Fn SSL_CIPHER_description
cannot handle a built-in cipher,
the according description of the cipher property is
.Qq unknown .
This case should not occur.