NAME

       CT_POLICY_EVAL_CTX_new, CT_POLICY_EVAL_CTX_free, CT_POLICY_EVAL_CTX_get0_cert,
       CT_POLICY_EVAL_CTX_set1_cert, CT_POLICY_EVAL_CTX_get0_issuer, CT_POLICY_EVAL_CTX_set1_issuer,
       CT_POLICY_EVAL_CTX_get0_log_store, CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE,
       CT_POLICY_EVAL_CTX_get_time, CT_POLICY_EVAL_CTX_set_time - Encapsulates the data required to evaluate
       whether SCTs meet a Certificate Transparency policy

SYNOPSIS

        #include <openssl/ct.h>

        CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void);
        void CT_POLICY_EVAL_CTX_free(CT_POLICY_EVAL_CTX *ctx);
        X509* CT_POLICY_EVAL_CTX_get0_cert(const CT_POLICY_EVAL_CTX *ctx);
        int CT_POLICY_EVAL_CTX_set1_cert(CT_POLICY_EVAL_CTX *ctx, X509 *cert);
        X509* CT_POLICY_EVAL_CTX_get0_issuer(const CT_POLICY_EVAL_CTX *ctx);
        int CT_POLICY_EVAL_CTX_set1_issuer(CT_POLICY_EVAL_CTX *ctx, X509 *issuer);
        const CTLOG_STORE *CT_POLICY_EVAL_CTX_get0_log_store(const CT_POLICY_EVAL_CTX *ctx);
        void CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE(CT_POLICY_EVAL_CTX *ctx,
                                                       CTLOG_STORE *log_store);
        uint64_t CT_POLICY_EVAL_CTX_get_time(const CT_POLICY_EVAL_CTX *ctx);
        void CT_POLICY_EVAL_CTX_set_time(CT_POLICY_EVAL_CTX *ctx, uint64_t time_in_ms);

DESCRIPTION

       A CT_POLICY_EVAL_CTX is used by functions that evaluate whether Signed Certificate Timestamps (SCTs)
       fulfil a Certificate Transparency (CT) policy.  This policy may be, for example, that at least one valid
       SCT is available. To determine this, an SCT's timestamp and signature must be verified.  This requires:

       • the public key of the log that issued the SCT

       • the certificate that the SCT was issued for

       • the issuer certificate (if the SCT was issued for a pre-certificate)

       • the current time

       The above requirements are met using the setters described below.

       CT_POLICY_EVAL_CTX_new() creates an empty policy evaluation context. This should then be populated using:

       • CT_POLICY_EVAL_CTX_set1_cert() to provide the certificate the SCTs were issued for

         Increments the reference count of the certificate.

       • CT_POLICY_EVAL_CTX_set1_issuer() to provide the issuer certificate

         Increments the reference count of the certificate.

       • CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE()  to  provide  a list of logs that are trusted as sources of
         SCTs

         Holds a pointer to the CTLOG_STORE, so the CTLOG_STORE must outlive the CT_POLICY_EVAL_CTX.

       • CT_POLICY_EVAL_CTX_set_time() to set the time SCTs should be compared with to  determine  if  they  are
         valid

         The  SCT  timestamp  will  be  compared to this time to check whether the SCT was issued in the future.
         RFC6962 states that "TLS clients MUST reject SCTs whose timestamp is in the future". By  default,  this
         will be set to 5 minutes in the future (e.g. (time() + 300) * 1000), to allow for clock drift.

         The time should be in milliseconds since the Unix epoch.

       Each setter has a matching getter for accessing the current value.

       When  no  longer required, the CT_POLICY_EVAL_CTX should be passed to CT_POLICY_EVAL_CTX_free() to delete
       it.

NOTES

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

RETURN VALUES

       CT_POLICY_EVAL_CTX_new() will return NULL if malloc fails.

SEE ALSO

       ct(7)

HISTORY

       These functions were added in OpenSSL 1.1.0.

COPYRIGHT

       Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.

       Licensed  under the OpenSSL license (the "License").  You may not use this file except in compliance with
       the  License.   You  can  obtain  a  copy  in  the  file  LICENSE  in  the  source  distribution  or   at
       <https://www.openssl.org/source/license.html>.

1.1.1f                                             2025-02-05                       CT_POLICY_EVAL_CTX_NEW(3SSL)