1.\"	$OpenBSD: SSL_CTX_set1_groups.3,v 1.2 2017/08/19 19:36:39 schwarze Exp $
2.\"	OpenSSL SSL_CTX_set1_curves.pod de4d764e Nov 9 14:51:06 2016 +0000
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51.Dd $Mdocdate: August 19 2017 $
52.Dt SSL_CTX_SET1_GROUPS 3
53.Os
54.Sh NAME
55.Nm SSL_CTX_set1_groups ,
56.Nm SSL_CTX_set1_groups_list ,
57.Nm SSL_set1_groups ,
58.Nm SSL_set1_groups_list ,
59.Nm SSL_CTX_set1_curves ,
60.Nm SSL_CTX_set1_curves_list ,
61.Nm SSL_set1_curves ,
62.Nm SSL_set1_curves_list
63.Nd choose supported EC groups
64.Sh SYNOPSIS
65.In openssl/ssl.h
66.Ft int
67.Fo SSL_CTX_set1_groups
68.Fa "SSL_CTX *ctx"
69.Fa "const int *glist"
70.Fa "size_t glistlen"
71.Fc
72.Ft int
73.Fo SSL_CTX_set1_groups_list
74.Fa "SSL_CTX *ctx"
75.Fa "const char *list"
76.Fc
77.Ft int
78.Fo SSL_set1_groups
79.Fa "SSL *ssl"
80.Fa "const int *glist"
81.Fa "size_t glistlen"
82.Fc
83.Ft int
84.Fo SSL_set1_groups_list
85.Fa "SSL *ssl"
86.Fa "const char *list"
87.Fc
88.Ft int
89.Fo SSL_CTX_set1_curves
90.Fa "SSL_CTX *ctx"
91.Fa "const int *clist"
92.Fa "size_t clistlen"
93.Fc
94.Ft int
95.Fo SSL_CTX_set1_curves_list
96.Fa "SSL_CTX *ctx"
97.Fa "const char *list"
98.Fc
99.Ft int
100.Fo SSL_set1_curves
101.Fa "SSL *ssl"
102.Fa "const int *clist"
103.Fa "size_t clistlen"
104.Fc
105.Ft int
106.Fo SSL_set1_curves_list
107.Fa "SSL *ssl"
108.Fa "const char *list"
109.Fc
110.Sh DESCRIPTION
111.Fn SSL_CTX_set1_groups
112sets the supported groups for
113.Fa ctx
114to the
115.Fa glistlen
116groups in the array
117.Fa glist .
118The array consists of group NIDs in preference order.
119For a TLS client, the groups are used directly in the supported groups
120extension.
121For a TLS server, the groups are used to determine the set of shared
122groups.
123.Pp
124.Fn SSL_CTX_set1_groups_list
125sets the supported groups for
126.Fa ctx
127to the
128.Fa list
129represented as a colon separated list of group NIDs or names, for example
130"P-521:P-384:P-256".
131.Pp
132.Fn SSL_set1_groups
133and
134.Fn SSL_set1_groups_list
135are similar except that they set supported groups for the SSL structure
136.Fa ssl
137only.
138.Pp
139The curve functions are deprecated synonyms for the equivalently
140named group functions and are identical in every respect except
141that they are implemented as macros.
142They exist because prior to TLS1.3, there was only the concept of
143supported curves.
144In TLS1.3, this was renamed to supported groups and extended to include
145Diffie Hellman groups.
146.Pp
147If an application wishes to make use of several of these functions for
148configuration purposes either on a command line or in a file, it should
149consider using the SSL_CONF interface instead of manually parsing
150options.
151.Sh RETURN VALUES
152All these functions return 1 for success or 0 for failure.
153.Sh SEE ALSO
154.Xr ssl 3 ,
155.Xr SSL_CTX_add_extra_chain_cert 3 ,
156.Xr SSL_CTX_set_cipher_list 3 ,
157.Xr SSL_CTX_set_options 3 ,
158.Xr SSL_new 3
159.Sh HISTORY
160The curve functions first appeared in OpenSSL 1.0.2
161and the group functions in OpenSSL 1.1.1.
162Both have been available since
163.Ox 6.1 .
164