=head1 NAME
-SSL_CTX_set1_curves, SSL_CTX_set1_curves_list, SSL_set1_curves,
-SSL_set1_curves_list, SSL_get1_curves, SSL_get_shared_curve - EC supported curve functions
+SSL_CTX_set1_groups, SSL_CTX_set1_groups_list, SSL_set1_groups,
+SSL_set1_groups_list, SSL_get1_groups, SSL_get_shared_group,
+SSL_get_negotiated_group, SSL_CTX_set1_curves, SSL_CTX_set1_curves_list,
+SSL_set1_curves, SSL_set1_curves_list, SSL_get1_curves, SSL_get_shared_curve
+- EC supported curve functions
=head1 SYNOPSIS
#include <openssl/ssl.h>
+ int SSL_CTX_set1_groups(SSL_CTX *ctx, int *glist, int glistlen);
+ int SSL_CTX_set1_groups_list(SSL_CTX *ctx, char *list);
+
+ int SSL_set1_groups(SSL *ssl, int *glist, int glistlen);
+ int SSL_set1_groups_list(SSL *ssl, char *list);
+
+ int SSL_get1_groups(SSL *ssl, int *groups);
+ int SSL_get_shared_group(SSL *s, int n);
+ int SSL_get_negotiated_group(SSL *s);
+
int SSL_CTX_set1_curves(SSL_CTX *ctx, int *clist, int clistlen);
int SSL_CTX_set1_curves_list(SSL_CTX *ctx, char *list);
=head1 DESCRIPTION
-SSL_CTX_set1_curves() sets the supported curves for B<ctx> to B<clistlen>
-curves in the array B<clist>. The array consist of all NIDs of curves in
-preference order. For a TLS client the curves are used directly in the
-supported curves extension. For a TLS server the curves are used to
-determine the set of shared curves.
-
-SSL_CTX_set1_curves_list() sets the supported curves for B<ctx> to
-string B<list>. The string is a colon separated list of curve NIDs or
-names, for example "P-521:P-384:P-256".
-
-SSL_set1_curves() and SSL_set1_curves_list() are similar except they set
-supported curves for the SSL structure B<ssl>.
-
-SSL_get1_curves() returns the set of supported curves sent by a client
-in the supported curves extension. It returns the total number of
-supported curves. The B<curves> parameter can be B<NULL> to simply
-return the number of curves for memory allocation purposes. The
-B<curves> array is in the form of a set of curve NIDs in preference
-order. It can return zero if the client did not send a supported curves
-extension.
-
-SSL_get_shared_curve() returns shared curve B<n> for a server-side
-SSL B<ssl>. If B<n> is -1 then the total number of shared curves is
+For all of the functions below that set the supported groups there must be at
+least one group in the list. A number of these functions identify groups via a
+unique integer NID value. However support for some groups may be added by
+external providers. In this case there will be no NID assigned for the group.
+When setting such groups applications should use the "list" form of these
+functions (i.e. SSL_CTX_set1_groups_list() and SSL_set1_groups_list).
+
+SSL_CTX_set1_groups() sets the supported groups for B<ctx> to B<glistlen>
+groups in the array B<glist>. The array consist of all NIDs of groups in
+preference order. For a TLS client the groups are used directly in the
+supported groups extension. For a TLS server the groups are used to
+determine the set of shared groups. Currently supported groups for
+B<TLSv1.3> are B<NID_X9_62_prime256v1>, B<NID_secp384r1>, B<NID_secp521r1>,
+B<NID_X25519>, B<NID_X448>, B<NID_ffdhe2048>, B<NID_ffdhe3072>,
+B<NID_ffdhe4096>, B<NID_ffdhe6144> and B<NID_ffdhe8192>.
+
+SSL_CTX_set1_groups_list() sets the supported groups for B<ctx> to
+string B<list>. The string is a colon separated list of group NIDs or
+names, for example "P-521:P-384:P-256:X25519:ffdhe2048". Currently supported
+groups for B<TLSv1.3> are B<P-256>, B<P-384>, B<P-521>, B<X25519>, B<X448>,
+B<ffdhe2048>, B<ffdhe3072>, B<ffdhe4096>, B<ffdhe6144>, B<ffdhe8192>. Support
+for other groups may be added by external providers.
+
+SSL_set1_groups() and SSL_set1_groups_list() are similar except they set
+supported groups for the SSL structure B<ssl>.
+
+SSL_get1_groups() returns the set of supported groups sent by a client
+in the supported groups extension. It returns the total number of
+supported groups. The B<groups> parameter can be B<NULL> to simply
+return the number of groups for memory allocation purposes. The
+B<groups> array is in the form of a set of group NIDs in preference
+order. It can return zero if the client did not send a supported groups
+extension. If a supported group NID is unknown then the value is set to the
+bitwise OR of TLSEXT_nid_unknown (0x1000000) and the id of the group.
+
+SSL_get_shared_group() returns the NID of the shared group B<n> for a
+server-side SSL B<ssl>. If B<n> is -1 then the total number of shared groups is
returned, which may be zero. Other than for diagnostic purposes,
-most applications will only be interested in the first shared curve
+most applications will only be interested in the first shared group
so B<n> is normally set to zero. If the value B<n> is out of range,
-NID_undef is returned.
+NID_undef is returned. If the NID for the shared group is unknown then the value
+is set to the bitwise OR of TLSEXT_nid_unknown (0x1000000) and the id of the
+group.
+
+SSL_get_negotiated_group() returns the NID of the negotiated group on a TLSv1.3
+connection for key exchange. This can be called by either client or server. If
+the NID for the shared group is unknown then the value is set to the bitwise OR
+of TLSEXT_nid_unknown (0x1000000) and the id of the group.
All these functions are implemented as macros.
+The curve functions are synonyms for the equivalently named group functions and
+are identical in every respect. They exist because, prior to TLS1.3, there was
+only the concept of supported curves. In TLS1.3 this was renamed to supported
+groups, and extended to include Diffie Hellman groups. The group functions
+should be used in preference.
+
=head1 NOTES
If an application wishes to make use of several of these functions for
=head1 RETURN VALUES
-SSL_CTX_set1_curves(), SSL_CTX_set1_curves_list(), SSL_set1_curves() and
-SSL_set1_curves_list(), return 1 for success and 0 for failure.
+SSL_CTX_set1_groups(), SSL_CTX_set1_groups_list(), SSL_set1_groups() and
+SSL_set1_groups_list(), return 1 for success and 0 for failure.
-SSL_get1_curves() returns the number of curves, which may be zero.
+SSL_get1_groups() returns the number of groups, which may be zero.
-SSL_get_shared_curve() returns the NID of shared curve B<n> or NID_undef if there
-is no shared curve B<n>; or the total number of shared curves if B<n>
+SSL_get_shared_group() returns the NID of shared group B<n> or NID_undef if there
+is no shared group B<n>; or the total number of shared groups if B<n>
is -1.
-When called on a client B<ssl>, SSL_get_shared_curve() has no meaning and
+When called on a client B<ssl>, SSL_get_shared_group() has no meaning and
returns -1.
+SSL_get_negotiated_group() returns the NID of the negotiated group on a
+TLSv1.3 connection for key exchange. Or it returns NID_undef if no negotiated
+group.
+
=head1 SEE ALSO
+L<ssl(7)>,
L<SSL_CTX_add_extra_chain_cert(3)>
=head1 HISTORY
-These functions were first added to OpenSSL 1.0.2.
+The curve functions were added in OpenSSL 1.0.2. The equivalent group
+functions were added in OpenSSL 1.1.1. The SSL_get_negotiated_group() function
+was added in OpenSSL 3.0.0.
=head1 COPYRIGHT
-Copyright 2013-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2013-2018 The OpenSSL Project Authors. All Rights Reserved.
-Licensed under the OpenSSL license (the "License"). You may not use
+Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.
projects / openssl.git / blobdiff