Codebase list openssl / b70f619
Add documentation for the SSL_export_keying_material() function Reviewed-by: Rich Salz <rsalz@openssl.org> (Merged from https://github.com/openssl/openssl/pull/3738) Matt Caswell 6 years ago
3 changed file(s) with 65 addition(s) and 4 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
+3
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ssl/ssl_lib.c less more
18241824
18251825 int SSL_export_keying_material(SSL *s, unsigned char *out, size_t olen,
18261826 const char *label, size_t llen,
1827 const unsigned char *p, size_t plen,
1827 const unsigned char *context, size_t contextlen,
18281828 int use_context)
18291829 {
18301830 if (s->version < TLS1_VERSION && s->version != DTLS1_BAD_VER)
18311831 return -1;
18321832
18331833 return s->method->ssl3_enc->export_keying_material(s, out, olen, label,
1834 llen, p, plen,
1835 use_context);
1834 llen, context,
1835 contextlen, use_context);
18361836 }
18371837
18381838 static unsigned long ssl_session_hash(const SSL_SESSION *a)
+1
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ssl/tls1.h less more
316316 */
317317 int SSL_export_keying_material(SSL *s, unsigned char *out, size_t olen,
318318 const char *label, size_t llen,
319 const unsigned char *p, size_t plen,
319 const unsigned char *context, size_t contextlen,
320320 int use_context);
321321
322322 int SSL_get_sigalgs(SSL *s, int idx,