1CT_POLICY_EVAL_CTX_NEW(3ossl)       OpenSSL      CT_POLICY_EVAL_CTX_NEW(3ossl)
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NAME

6       CT_POLICY_EVAL_CTX_new_ex, CT_POLICY_EVAL_CTX_new,
7       CT_POLICY_EVAL_CTX_free, CT_POLICY_EVAL_CTX_get0_cert,
8       CT_POLICY_EVAL_CTX_set1_cert, CT_POLICY_EVAL_CTX_get0_issuer,
9       CT_POLICY_EVAL_CTX_set1_issuer, CT_POLICY_EVAL_CTX_get0_log_store,
10       CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE, CT_POLICY_EVAL_CTX_get_time,
11       CT_POLICY_EVAL_CTX_set_time - Encapsulates the data required to
12       evaluate whether SCTs meet a Certificate Transparency policy
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SYNOPSIS

15        #include <openssl/ct.h>
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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);
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DESCRIPTION

32       A CT_POLICY_EVAL_CTX is used by functions that evaluate whether Signed
33       Certificate Timestamps (SCTs) fulfil a Certificate Transparency (CT)
34       policy.  This policy may be, for example, that at least one valid SCT
35       is available. To determine this, an SCT's timestamp and signature must
36       be verified.  This requires:
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38       • the public key of the log that issued the SCT
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40       • the certificate that the SCT was issued for
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42       • the issuer certificate (if the SCT was issued for a pre-certificate)
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44       • the current time
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46       The above requirements are met using the setters described below.
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48       CT_POLICY_EVAL_CTX_new_ex() creates an empty policy evaluation context
49       and associates it with the given library context libctx and property
50       query string propq.
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52       CT_POLICY_EVAL_CTX_new() does the same thing as
53       CT_POLICY_EVAL_CTX_new_ex() except that it uses the default library
54       context and property query string.
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56       The CT_POLICY_EVAL_CTX should then be populated using:
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58       • CT_POLICY_EVAL_CTX_set1_cert() to provide the certificate the SCTs
59         were issued for
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61         Increments the reference count of the certificate.
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63       • CT_POLICY_EVAL_CTX_set1_issuer() to provide the issuer certificate
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65         Increments the reference count of the certificate.
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67       • CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE() to provide a list of logs
68         that are trusted as sources of SCTs
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70         Holds a pointer to the CTLOG_STORE, so the CTLOG_STORE must outlive
71         the CT_POLICY_EVAL_CTX.
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73       • CT_POLICY_EVAL_CTX_set_time() to set the time SCTs should be compared
74         with to determine if they are valid
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76         The SCT timestamp will be compared to this time to check whether the
77         SCT was issued in the future. RFC6962 states that "TLS clients MUST
78         reject SCTs whose timestamp is in the future". By default, this will
79         be set to 5 minutes in the future (e.g. (time() + 300) * 1000), to
80         allow for clock drift.
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82         The time should be in milliseconds since the Unix Epoch.
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84       Each setter has a matching getter for accessing the current value.
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86       When no longer required, the CT_POLICY_EVAL_CTX should be passed to
87       CT_POLICY_EVAL_CTX_free() to delete it.
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NOTES

90       The issuer certificate only needs to be provided if at least one of the
91       SCTs was issued for a pre-certificate. This will be the case for SCTs
92       embedded in a certificate (i.e. those in an X.509 extension), but may
93       not be the case for SCTs found in the TLS SCT extension or OCSP
94       response.
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RETURN VALUES

97       CT_POLICY_EVAL_CTX_new_ex() and CT_POLICY_EVAL_CTX_new() will return
98       NULL if malloc fails.
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SEE ALSO

101       ct(7)
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HISTORY

104       CT_POLICY_EVAL_CTX_new_ex was added in OpenSSL 3.0. All other functions
105       were added in OpenSSL 1.1.0.
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108       Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
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110       Licensed under the Apache License 2.0 (the "License").  You may not use
111       this file except in compliance with the License.  You can obtain a copy
112       in the file LICENSE in the source distribution or at
113       <https://www.openssl.org/source/license.html>.
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1173.1.1                             2023-08-31     CT_POLICY_EVAL_CTX_NEW(3ossl)
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