1=pod
2
3=head1 NAME
4
5CT_POLICY_EVAL_CTX_new, CT_POLICY_EVAL_CTX_free,
6CT_POLICY_EVAL_CTX_get0_cert, CT_POLICY_EVAL_CTX_set1_cert,
7CT_POLICY_EVAL_CTX_get0_issuer, CT_POLICY_EVAL_CTX_set1_issuer,
8CT_POLICY_EVAL_CTX_get0_log_store, CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE,
9CT_POLICY_EVAL_CTX_get_time, CT_POLICY_EVAL_CTX_set_time -
10Encapsulates the data required to evaluate whether SCTs meet a Certificate Transparency policy
11
12=head1 SYNOPSIS
13
14 #include <openssl/ct.h>
15
16 CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void);
17 void CT_POLICY_EVAL_CTX_free(CT_POLICY_EVAL_CTX *ctx);
18 X509* CT_POLICY_EVAL_CTX_get0_cert(const CT_POLICY_EVAL_CTX *ctx);
19 int CT_POLICY_EVAL_CTX_set1_cert(CT_POLICY_EVAL_CTX *ctx, X509 *cert);
20 X509* CT_POLICY_EVAL_CTX_get0_issuer(const CT_POLICY_EVAL_CTX *ctx);
21 int CT_POLICY_EVAL_CTX_set1_issuer(CT_POLICY_EVAL_CTX *ctx, X509 *issuer);
22 const CTLOG_STORE *CT_POLICY_EVAL_CTX_get0_log_store(const CT_POLICY_EVAL_CTX *ctx);
23 void CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE(CT_POLICY_EVAL_CTX *ctx,
24                                                CTLOG_STORE *log_store);
25 uint64_t CT_POLICY_EVAL_CTX_get_time(const CT_POLICY_EVAL_CTX *ctx);
26 void CT_POLICY_EVAL_CTX_set_time(CT_POLICY_EVAL_CTX *ctx, uint64_t time_in_ms);
27
28=head1 DESCRIPTION
29
30A B<CT_POLICY_EVAL_CTX> is used by functions that evaluate whether Signed
31Certificate Timestamps (SCTs) fulfil a Certificate Transparency (CT) policy.
32This policy may be, for example, that at least one valid SCT is available. To
33determine this, an SCT's timestamp and signature must be verified.
34This requires:
35
36=over 2
37
38=item *
39
40the public key of the log that issued the SCT
41
42=item *
43
44the certificate that the SCT was issued for
45
46=item *
47
48the issuer certificate (if the SCT was issued for a pre-certificate)
49
50=item *
51
52the current time
53
54=back
55
56The above requirements are met using the setters described below.
57
58CT_POLICY_EVAL_CTX_new() creates an empty policy evaluation context. This
59should then be populated using:
60
61=over 2
62
63=item *
64
65CT_POLICY_EVAL_CTX_set1_cert() to provide the certificate the SCTs were issued for
66
67Increments the reference count of the certificate.
68
69=item *
70
71CT_POLICY_EVAL_CTX_set1_issuer() to provide the issuer certificate
72
73Increments the reference count of the certificate.
74
75=item *
76
77CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE() to provide a list of logs that are trusted as sources of SCTs
78
79Holds a pointer to the CTLOG_STORE, so the CTLOG_STORE must outlive the
80CT_POLICY_EVAL_CTX.
81
82=item *
83
84CT_POLICY_EVAL_CTX_set_time() to set the time SCTs should be compared with to determine if they are valid
85
86The SCT timestamp will be compared to this time to check whether the SCT was
87issued in the future. RFC6962 states that "TLS clients MUST reject SCTs whose
88timestamp is in the future". By default, this will be set to 5 minutes in the
89future (e.g. (time() + 300) * 1000), to allow for clock drift.
90
91The time should be in milliseconds since the Unix epoch.
92
93=back
94
95Each setter has a matching getter for accessing the current value.
96
97When no longer required, the B<CT_POLICY_EVAL_CTX> should be passed to
98CT_POLICY_EVAL_CTX_free() to delete it.
99
100=head1 NOTES
101
102The issuer certificate only needs to be provided if at least one of the SCTs
103was issued for a pre-certificate. This will be the case for SCTs embedded in a
104certificate (i.e. those in an X.509 extension), but may not be the case for SCTs
105found in the TLS SCT extension or OCSP response.
106
107=head1 RETURN VALUES
108
109CT_POLICY_EVAL_CTX_new() will return NULL if malloc fails.
110
111=head1 SEE ALSO
112
113L<ct(7)>
114
115=head1 HISTORY
116
117These functions were added in OpenSSL 1.1.0.
118
119=head1 COPYRIGHT
120
121Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
122
123Licensed under the OpenSSL license (the "License").  You may not use
124this file except in compliance with the License.  You can obtain a copy
125in the file LICENSE in the source distribution or at
126L<https://www.openssl.org/source/license.html>.
127
128=cut
129