Codebase list openssl / 2f4a4df
Add documentation for the SSL_export_keying_material() function Reviewed-by: Rich Salz <rsalz@openssl.org> (Merged from https://github.com/openssl/openssl/pull/3736) Matt Caswell 6 years ago
3 changed file(s) with 68 addition(s) and 7 deletion(s). Raw diff Collapse all Expand all
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doc/ssl/SSL_export_keying_material.pod less more
0 =pod
1
2 =head1 NAME
3
4 SSL_export_keying_material - obtain keying material for application use
5
6 =head1 SYNOPSIS
7
8 #include <openssl/ssl.h>
9
10 int SSL_export_keying_material(SSL *s, unsigned char *out, size_t olen,
11 const char *label, size_t llen,
12 const unsigned char *context,
13 size_t contextlen, int use_context);
14
15 =head1 DESCRIPTION
16
17 During the creation of a TLS or DTLS connection shared keying material is
18 established between the two endpoints. The function SSL_export_keying_material()
19 enables an application to use some of this keying material for its own purposes
20 in accordance with RFC5705.
21
22 An application may need to securely establish the context within which this
23 keying material will be used. For example this may include identifiers for the
24 application session, application algorithms or parameters, or the lifetime of
25 the context. The context value is left to the application but must be the same
26 on both sides of the communication.
27
28 For a given SSL connection B<s>, B<olen> bytes of data will be written to
29 B<out>. The application specific context should be supplied in the location
30 pointed to by B<context> and should be B<contextlen> bytes long. Provision of
31 a context is optional. If the context should be omitted entirely then
32 B<use_context> should be set to 0. Otherwise it should be any other value. If
33 B<use_context> is 0 then the values of B<context> and B<contextlen> are ignored.
34 Note that a zero length context is treated differently to no context at all, and
35 will result in different keying material being returned.
36
37 An application specific label should be provided in the location pointed to by
38 B<label> and should be B<llen> bytes long. Typically this will be a value from
39 the IANA Exporter Label Registry
40 (L<https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#exporter-labels>).
41 Alternatively labels beginning with "EXPERIMENTAL" are permitted by the standard
42 to be used without registration.
43
44 Note that this function is only defined for TLSv1.0 and above, and DTLSv1.0 and
45 above. Attempting to use it in SSLv3 will result in an error.
46
47 =head1 RETURN VALUES
48
49 SSL_export_keying_material() returns 0 or -1 on failure or 1 on success.
50
51 =head1 COPYRIGHT
52
53 Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
54
55 Licensed under the OpenSSL license (the "License"). You may not use
56 this file except in compliance with the License. You can obtain a copy
57 in the file LICENSE in the source distribution or at
58 L<https://www.openssl.org/source/license.html>.
59
60 =cut
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include/openssl/tls1.h less more
225225 * as specified in RFC 5705. It writes |olen| bytes to |out| given a label and
226226 * optional context. (Since a zero length context is allowed, the |use_context|
227227 * flag controls whether a context is included.) It returns 1 on success and
228 * zero otherwise.
228 * 0 or -1 otherwise.
229229 */
230230 __owur int SSL_export_keying_material(SSL *s, unsigned char *out, size_t olen,
231 const char *label, size_t llen,
232 const unsigned char *p, size_t plen,
233 int use_context);
231 const char *label, size_t llen,
232 const unsigned char *context,
233 size_t contextlen, int use_context);
234234
235235 int SSL_get_sigalgs(SSL *s, int idx,
236236 int *psign, int *phash, int *psignandhash,
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ssl/ssl_lib.c less more
22912291
22922292 int SSL_export_keying_material(SSL *s, unsigned char *out, size_t olen,
22932293 const char *label, size_t llen,
2294 const unsigned char *p, size_t plen,
2294 const unsigned char *context, size_t contextlen,
22952295 int use_context)
22962296 {
22972297 if (s->version < TLS1_VERSION && s->version != DTLS1_BAD_VER)
22982298 return -1;
22992299
23002300 return s->method->ssl3_enc->export_keying_material(s, out, olen, label,
2301 llen, p, plen,
2302 use_context);
2301 llen, context,
2302 contextlen, use_context);
23032303 }
23042304
23052305 static unsigned long ssl_session_hash(const SSL_SESSION *a)