path: root/src/lib/libssl/man/SSL_get_ciphers.3

.\" $OpenBSD: SSL_get_ciphers.3,v 1.7 2019/01/22 01:18:24 tb Exp $
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.\" Nick Mathewson <nickm@torproject.org>, and Kazuki Yamaguchi <k@rhe.jp>.
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.Dd $Mdocdate: January 22 2019 $
.Dt SSL_GET_CIPHERS 3
.Os
.Sh NAME
.Nm SSL_get_ciphers ,
.Nm SSL_CTX_get_ciphers ,
.Nm SSL_get1_supported_ciphers ,
.Nm SSL_get_client_ciphers ,
.Nm SSL_get_cipher_list
.Nd get list of available SSL_CIPHERs
.Sh SYNOPSIS
.In openssl/ssl.h
.Ft STACK_OF(SSL_CIPHER) *
.Fn SSL_get_ciphers "const SSL *ssl"
.Ft STACK_OF(SSL_CIPHER) *
.Fn SSL_CTX_get_ciphers "const SSL_CTX *ctx"
.Ft STACK_OF(SSL_CIPHER) *
.Fn SSL_get1_supported_ciphers "SSL *ssl"
.Ft STACK_OF(SSL_CIPHER) *
.Fn SSL_get_client_ciphers "const SSL *ssl"
.Ft const char *
.Fn SSL_get_cipher_list "const SSL *ssl" "int priority"
.Sh DESCRIPTION
.Fn SSL_get_ciphers
returns the stack of available
.Vt SSL_CIPHER Ns s
for
.Fa ssl ,
sorted by preference.
If
.Fa ssl
is
.Dv NULL
or no ciphers are available,
.Dv NULL
is returned.
.Pp
.Fn SSL_CTX_get_ciphers
returns the stack of available
.Vt SSL_CIPHER Ns s
for
.Fa ctx .
.Pp
.Fn SSL_get1_supported_ciphers
returns the stack of enabled
.Vt SSL_CIPHER Ns s
for
.Fa ssl
as it would be sent in a ClientHello, sorted by preference.
The list depends on settings like the cipher list, the supported
protocol versions, the security level, and the enabled signature
algorithms.
The list of ciphers that would be sent in a ClientHello can differ
from the list of ciphers that would be acceptable when acting as a
server.
For example,
additional ciphers may be usable by a server if there is a gap in the
list of supported protocols, and some ciphers may not be usable by a
server if there is not a suitable certificate configured.
If
.Fa ssl
is
.Dv NULL
or no ciphers are available,
.Dv NULL
is returned.
.Pp
.Fn SSL_get_client_ciphers
returns the stack of available
.Vt SSL_CIPHER Ns s
matching the list received from the client on
.Fa ssl .
If
.Fa ssl
is
.Dv NULL ,
no ciphers are available, or
.Fa ssl
is not operating in server mode,
.Dv NULL
is returned.
.Pp
.Fn SSL_get_ciphers ,
.Fn SSL_CTX_get_ciphers ,
and
.Fn SSL_get_client_ciphers
return pointers to internal cipher stacks, which will be freed
later on when the
.Vt SSL
or
.Vt SSL_CTX
object is freed.
Therefore, the calling code must not free the return value itself.
.Pp
The details of the ciphers obtained by
.Fn SSL_get_ciphers ,
.Fn SSL_CTX_get_ciphers ,
.Fn SSL_get1_supported_ciphers ,
and
.Fn SSL_get_client_ciphers
can be obtained using the
.Xr SSL_CIPHER_get_name 3
family of functions.
.Pp
.Fn SSL_get_cipher_list
returns a pointer to the name of the
.Vt SSL_CIPHER
listed for
.Fa ssl
with
.Fa priority .
If
.Fa ssl
is
.Dv NULL ,
no ciphers are available, or there are fewer ciphers than
.Fa priority
available,
.Dv NULL
is returned.
.Pp
Call
.Fn SSL_get_cipher_list
with
.Fa priority
starting from 0 to obtain the sorted list of available ciphers, until
.Dv NULL
is returned.
.Sh SEE ALSO
.Xr ssl 3 ,
.Xr SSL_CIPHER_get_name 3 ,
.Xr SSL_CTX_set_cipher_list 3
.Sh HISTORY
.Fn SSL_get_cipher_list
first appeared in SSLeay 0.5.2.
.Fn SSL_get_ciphers
first appeared in SSLeay 0.8.0.
Both functions have been available since
.Ox 2.4 .
.Pp
.Fn SSL_CTX_get_ciphers
first appeared in OpenSSL 1.1.0 and has been available since
.Ox 6.3 .
.Pp
.Fn SSL_get1_supported_ciphers
and
.Fn SSL_get_client_ciphers
first appeared in OpenSSL 1.1.0 and has been available since
.Ox 6.5 .