gnutls_priority_init2(3) gnutls gnutls_priority_init2(3)
NAME
gnutls_priority_init2 - API function
SYNOPSIS
#include <gnutls/gnutls.h>
gnutls_priority_init2(3) * priority_cache, const char
* priorities, const char ** err_pos, unsigned flags);
ARGUMENTS
gnutls_priority_t * priority_cache
is a gnutls_priority_t type.
const char * priorities
is a string describing priorities (may be NULL)
const char ** err_pos
In case of an error this will have the position in the string
the error occurred
unsigned flags
zero or GNUTLS_PRIORITY_INIT_DEF_APPEND
DESCRIPTION
Sets priorities for the ciphers, key exchange methods, and macs. The
priority_cache should be deinitialized using gnutls_priority_deinit().
The priorities option allows you to specify a colon separated list of the
cipher priorities to enable. Some keywords are defined to provide quick
access to common preferences.
When flags is set to GNUTLS_PRIORITY_INIT_DEF_APPEND then the
priorities specified will be appended to the default options.
Unless there is a special need, use the "NORMAL" keyword to apply a
reasonable security level, or "NORMAL:%COMPAT" for compatibility.
"PERFORMANCE" means all the "secure" ciphersuites are enabled, limited to
128 bit ciphers and sorted by terms of speed performance.
"LEGACY" the NORMAL settings for GnuTLS 3.2.x or earlier. There is no
verification profile set, and the allowed DH primes are considered weak
today.
"NORMAL" means all "secure" ciphersuites. The 256-bit ciphers are
included as a fallback only. The ciphers are sorted by security margin.
"PFS" means all "secure" ciphersuites that support perfect forward
secrecy. The 256-bit ciphers are included as a fallback only. The
ciphers are sorted by security margin.
"SECURE128" means all "secure" ciphersuites of security level 128-bit or
more.
"SECURE192" means all "secure" ciphersuites of security level 192-bit or
more.
"SUITEB128" means all the NSA SuiteB ciphersuites with security level of
128.
"SUITEB192" means all the NSA SuiteB ciphersuites with security level of
192.
"NONE" means nothing is enabled. This disables everything, including
protocols.
"@KEYWORD1,KEYWORD2,..." The system administrator imposed settings. The
provided keyword(s) will be expanded from a configuration-time provided
file - default is: /etc/gnutls/config. Any attributes that follow it,
will be appended to the expanded string. If multiple keywords are
provided, separated by commas, then the first keyword that exists in the
configuration file will be used. At least one of the keywords must exist,
or this function will return an error. Typical usage would be to specify
an application specified keyword first, followed by "SYSTEM" as a default
fallback. e.g., " LIBVIRT ,SYSTEM:!-VERS-SSL3.0" will first try to find a
config file entry matching "LIBVIRT", but if that does not exist will use
the entry for "SYSTEM". If "SYSTEM" does not exist either, an error will
be returned. In all cases, the SSL3.0 protocol will be disabled. The
system priority file entries should be formatted as "KEYWORD=VALUE",
e.g., "SYSTEM=NORMAL:+ARCFOUR-128".
Special keywords are "!", "-" and "+". "!" or "-" appended with an
algorithm will remove this algorithm. "+" appended with an algorithm
will add this algorithm.
Check the GnuTLS manual section "Priority strings" for detailed
information.
EXAMPLES
"NONE:+VERS-TLS-ALL:+MAC-ALL:+RSA:+AES-128-CBC:+SIGN-ALL:+COMP-NULL"
"NORMAL:+ARCFOUR-128" means normal ciphers plus ARCFOUR-128.
"SECURE128:-VERS-SSL3.0" means that only secure ciphers are and enabled,
SSL3.0 is disabled.
"NONE:+VERS-TLS-ALL:+AES-128-CBC:+RSA:+SHA1:+COMP-NULL:+SIGN-RSA-SHA1",
"NONE:+VERS-TLS-ALL:+AES-128-CBC:+ECDHE-RSA:+SHA1:+COMP-NULL:+SIGN-RSA-SHA1:+CURVE-SECP256R1",
"SECURE256:+SECURE128",
Note that "NORMAL:%COMPAT" is the most compatible mode.
A NULL priorities string indicates the default priorities to be used
(this is available since GnuTLS 3.3.0).
RETURNS
On syntax error GNUTLS_E_INVALID_REQUEST is returned, GNUTLS_E_SUCCESS on
success, or an error code.
SINCE
3.6.3
REPORTING BUGS
Report bugs to <bugs@gnutls.org>.
Home page: https://www.gnutls.org
COPYRIGHT
Copyright (C) 2001- Free Software Foundation, Inc., and others.
Copying and distribution of this file, with or without modification, are
permitted in any medium without royalty provided the copyright notice and
this notice are preserved.
SEE ALSO
The full documentation for gnutls is maintained as a Texinfo manual. If
the /usr/share/doc/gnutls/ directory does not contain the HTML form visit
https://www.gnutls.org/manual/
gnutls 3.7.9 gnutls_priority_init2(3)
gnutls 3.7.9 - Generated Sun Feb 12 06:12:00 CST 2023