1=pod
2
3=head1 NAME
4
5CT_POLICY_EVAL_CTX_new_ex,
6CT_POLICY_EVAL_CTX_new, CT_POLICY_EVAL_CTX_free,
7CT_POLICY_EVAL_CTX_get0_cert, CT_POLICY_EVAL_CTX_set1_cert,
8CT_POLICY_EVAL_CTX_get0_issuer, CT_POLICY_EVAL_CTX_set1_issuer,
9CT_POLICY_EVAL_CTX_get0_log_store, CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE,
10CT_POLICY_EVAL_CTX_get_time, CT_POLICY_EVAL_CTX_set_time -
11Encapsulates the data required to evaluate whether SCTs meet a Certificate Transparency policy
12
13=head1 SYNOPSIS
14
15 #include <openssl/ct.h>
16
17 CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new_ex(OSSL_LIB_CTX *libctx,
18                                               const char *propq);
19 CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void);
20 void CT_POLICY_EVAL_CTX_free(CT_POLICY_EVAL_CTX *ctx);
21 X509* CT_POLICY_EVAL_CTX_get0_cert(const CT_POLICY_EVAL_CTX *ctx);
22 int CT_POLICY_EVAL_CTX_set1_cert(CT_POLICY_EVAL_CTX *ctx, X509 *cert);
23 X509* CT_POLICY_EVAL_CTX_get0_issuer(const CT_POLICY_EVAL_CTX *ctx);
24 int CT_POLICY_EVAL_CTX_set1_issuer(CT_POLICY_EVAL_CTX *ctx, X509 *issuer);
25 const CTLOG_STORE *CT_POLICY_EVAL_CTX_get0_log_store(const CT_POLICY_EVAL_CTX *ctx);
26 void CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE(CT_POLICY_EVAL_CTX *ctx,
27                                                CTLOG_STORE *log_store);
28 uint64_t CT_POLICY_EVAL_CTX_get_time(const CT_POLICY_EVAL_CTX *ctx);
29 void CT_POLICY_EVAL_CTX_set_time(CT_POLICY_EVAL_CTX *ctx, uint64_t time_in_ms);
30
31=head1 DESCRIPTION
32
33A B<CT_POLICY_EVAL_CTX> is used by functions that evaluate whether Signed
34Certificate Timestamps (SCTs) fulfil a Certificate Transparency (CT) policy.
35This policy may be, for example, that at least one valid SCT is available. To
36determine this, an SCT's timestamp and signature must be verified.
37This requires:
38
39=over 2
40
41=item *
42
43the public key of the log that issued the SCT
44
45=item *
46
47the certificate that the SCT was issued for
48
49=item *
50
51the issuer certificate (if the SCT was issued for a pre-certificate)
52
53=item *
54
55the current time
56
57=back
58
59The above requirements are met using the setters described below.
60
61CT_POLICY_EVAL_CTX_new_ex() creates an empty policy evaluation context
62and associates it with the given library context I<libctx> and property query
63string I<propq>.
64
65CT_POLICY_EVAL_CTX_new() does the same thing as
66CT_POLICY_EVAL_CTX_new_ex() except that it uses the default library
67context and property query string.
68
69The CT_POLICY_EVAL_CTX should then be populated using:
70
71=over 2
72
73=item *
74
75CT_POLICY_EVAL_CTX_set1_cert() to provide the certificate the SCTs were issued for
76
77Increments the reference count of the certificate.
78
79=item *
80
81CT_POLICY_EVAL_CTX_set1_issuer() to provide the issuer certificate
82
83Increments the reference count of the certificate.
84
85=item *
86
87CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE() to provide a list of logs that are trusted as sources of SCTs
88
89Holds a pointer to the CTLOG_STORE, so the CTLOG_STORE must outlive the
90CT_POLICY_EVAL_CTX.
91
92=item *
93
94CT_POLICY_EVAL_CTX_set_time() to set the time SCTs should be compared with to determine if they are valid
95
96The SCT timestamp will be compared to this time to check whether the SCT was
97issued in the future. RFC6962 states that "TLS clients MUST reject SCTs whose
98timestamp is in the future". By default, this will be set to 5 minutes in the
99future (e.g. (time() + 300) * 1000), to allow for clock drift.
100
101The time should be in milliseconds since the Unix Epoch.
102
103=back
104
105Each setter has a matching getter for accessing the current value.
106
107When no longer required, the B<CT_POLICY_EVAL_CTX> should be passed to
108CT_POLICY_EVAL_CTX_free() to delete it. If the argument to
109CT_POLICY_EVAL_CTX_free() is NULL, nothing is done.
110
111=head1 NOTES
112
113The issuer certificate only needs to be provided if at least one of the SCTs
114was issued for a pre-certificate. This will be the case for SCTs embedded in a
115certificate (i.e. those in an X.509 extension), but may not be the case for SCTs
116found in the TLS SCT extension or OCSP response.
117
118=head1 RETURN VALUES
119
120CT_POLICY_EVAL_CTX_new_ex() and CT_POLICY_EVAL_CTX_new() will return
121NULL if malloc fails.
122
123=head1 SEE ALSO
124
125L<ct(7)>
126
127=head1 HISTORY
128
129CT_POLICY_EVAL_CTX_new_ex was added in OpenSSL 3.0. All other
130functions were added in OpenSSL 1.1.0.
131
132=head1 COPYRIGHT
133
134Copyright 2016-2024 The OpenSSL Project Authors. All Rights Reserved.
135
136Licensed under the Apache License 2.0 (the "License").  You may not use
137this file except in compliance with the License.  You can obtain a copy
138in the file LICENSE in the source distribution or at
139L<https://www.openssl.org/source/license.html>.
140
141=cut
142