1 .\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.40)
4 .\" ========================================================================
5 .de Sp \" Vertical space (when we can't use .PP)
9 .de Vb \" Begin verbatim text
14 .de Ve \" End verbatim text
18 .\" Set up some character translations and predefined strings. \*(-- will
19 .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
20 .\" double quote, and \*(R" will give a right double quote. \*(C+ will
21 .\" give a nicer C++. Capital omega is used to do unbreakable dashes and
22 .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
23 .\" nothing in troff, for use with C<>.
25 .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
29 . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
30 . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
45 .\" Escape single quotes in literal strings from groff's Unicode transform.
49 .\" If the F register is >0, we'll generate index entries on stderr for
50 .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
51 .\" entries marked with X<> in POD. Of course, you'll have to process the
52 .\" output yourself in some meaningful fashion.
54 .\" Avoid warning from groff about undefined register 'F'.
58 .if \n(.g .if rF .nr rF 1
59 .if (\n(rF:(\n(.g==0)) \{\
62 . tm Index:\\$1\t\\n%\t"\\$2"
72 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
73 .\" Fear. Run. Save yourself. No user-serviceable parts.
74 . \" fudge factors for nroff and troff
83 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
89 . \" simple accents for nroff and troff
99 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
100 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
101 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
102 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
103 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
104 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
106 . \" troff and (daisy-wheel) nroff accents
107 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
108 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
109 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
110 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
111 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
112 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
113 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
114 .ds ae a\h'-(\w'a'u*4/10)'e
115 .ds Ae A\h'-(\w'A'u*4/10)'E
116 . \" corrections for vroff
117 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
118 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
119 . \" for low resolution devices (crt and lpr)
120 .if \n(.H>23 .if \n(.V>19 \
133 .\" ========================================================================
136 .TH X25519 7 "2020-04-21" "1.1.1g" "OpenSSL"
137 .\" For nroff, turn off justification. Always turn off hyphenation; it makes
138 .\" way too many mistakes in technical documents.
142 X25519, X448 \&\- EVP_PKEY X25519 and X448 support
144 .IX Header "DESCRIPTION"
145 The \fBX25519\fR and \fBX448\fR \s-1EVP_PKEY\s0 implementation supports key generation and
146 key derivation using \fBX25519\fR and \fBX448\fR. It has associated private and public
147 key formats compatible with \s-1RFC 8410.\s0
149 No additional parameters can be set during key generation.
151 The peer public key must be set using \fBEVP_PKEY_derive_set_peer()\fR when
152 performing key derivation.
155 A context for the \fBX25519\fR algorithm can be obtained by calling:
158 \& EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_X25519, NULL);
161 For the \fBX448\fR algorithm a context can be obtained by calling:
164 \& EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_X448, NULL);
167 X25519 or X448 private keys can be set directly using
168 \&\fBEVP_PKEY_new_raw_private_key\fR\|(3) or loaded from a PKCS#8 private key file
169 using \fBPEM_read_bio_PrivateKey\fR\|(3) (or similar function). Completely new keys
170 can also be generated (see the example below). Setting a private key also sets
171 the associated public key.
173 X25519 or X448 public keys can be set directly using
174 \&\fBEVP_PKEY_new_raw_public_key\fR\|(3) or loaded from a SubjectPublicKeyInfo
175 structure in a \s-1PEM\s0 file using \fBPEM_read_bio_PUBKEY\fR\|(3) (or similar function).
177 .IX Header "EXAMPLES"
178 This example generates an \fBX25519\fR private key and writes it to standard
179 output in \s-1PEM\s0 format:
182 \& #include <openssl/evp.h>
183 \& #include <openssl/pem.h>
185 \& EVP_PKEY *pkey = NULL;
186 \& EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_X25519, NULL);
187 \& EVP_PKEY_keygen_init(pctx);
188 \& EVP_PKEY_keygen(pctx, &pkey);
189 \& EVP_PKEY_CTX_free(pctx);
190 \& PEM_write_PrivateKey(stdout, pkey, NULL, NULL, 0, NULL, NULL);
193 The key derivation example in \fBEVP_PKEY_derive\fR\|(3) can be used with
194 \&\fBX25519\fR and \fBX448\fR.
196 .IX Header "SEE ALSO"
197 \&\fBEVP_PKEY_CTX_new\fR\|(3),
198 \&\fBEVP_PKEY_keygen\fR\|(3),
199 \&\fBEVP_PKEY_derive\fR\|(3),
200 \&\fBEVP_PKEY_derive_set_peer\fR\|(3)
202 .IX Header "COPYRIGHT"
203 Copyright 2017\-2020 The OpenSSL Project Authors. All Rights Reserved.
205 Licensed under the OpenSSL license (the \*(L"License\*(R"). You may not use
206 this file except in compliance with the License. You can obtain a copy
207 in the file \s-1LICENSE\s0 in the source distribution or at
208 <https://www.openssl.org/source/license.html>.