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SCT_validate(3)                     OpenSSL                    SCT_validate(3)



NAME
       SCT_validate, SCT_LIST_validate, SCT_get_validation_status - checks
       Signed Certificate Timestamps (SCTs) are valid

LIBRARY
       libcrypto, -lcrypto

SYNOPSIS
        #include <openssl/ct.h>

        typedef enum {
            SCT_VALIDATION_STATUS_NOT_SET,
            SCT_VALIDATION_STATUS_UNKNOWN_LOG,
            SCT_VALIDATION_STATUS_VALID,
            SCT_VALIDATION_STATUS_INVALID,
            SCT_VALIDATION_STATUS_UNVERIFIED,
            SCT_VALIDATION_STATUS_UNKNOWN_VERSION
        } sct_validation_status_t;

        int SCT_validate(SCT *sct, const CT_POLICY_EVAL_CTX *ctx);
        int SCT_LIST_validate(const STACK_OF(SCT) *scts, CT_POLICY_EVAL_CTX *ctx);
        sct_validation_status_t SCT_get_validation_status(const SCT *sct);

DESCRIPTION
       SCT_validate() will check that an SCT is valid and verify its
       signature.  SCT_LIST_validate() performs the same checks on an entire
       stack of SCTs.  The result of the validation checks can be obtained by
       passing the SCT to SCT_get_validation_status().

       A CT_POLICY_EVAL_CTX must be provided that specifies:

       ⊕ The certificate the SCT was issued for.

         Failure to provide the certificate will result in the validation
         status being SCT_VALIDATION_STATUS_UNVERIFIED.

       ⊕ The issuer of that certificate.

         This is only required if the SCT was issued for a pre-certificate
         (see RFC 6962). If it is required but not provided, the validation
         status will be SCT_VALIDATION_STATUS_UNVERIFIED.

       ⊕ A CTLOG_STORE that contains the CT log that issued this SCT.

         If the SCT was issued by a log that is not in this CTLOG_STORE, the
         validation status will be SCT_VALIDATION_STATUS_UNKNOWN_LOG.

       If the SCT is of an unsupported version (only v1 is currently
       supported), the validation status will be
       SCT_VALIDATION_STATUS_UNKNOWN_VERSION.

       If the SCT's signature is incorrect, its timestamp is in the future
       (relative to the time in CT_POLICY_EVAL_CTX), or if it is otherwise
       invalid, the validation status will be SCT_VALIDATION_STATUS_INVALID.

       If all checks pass, the validation status will be
       SCT_VALIDATION_STATUS_VALID.

NOTES
       A return value of 0 from SCT_LIST_validate() should not be interpreted
       as a failure. At a minimum, only one valid SCT may provide sufficient
       confidence that a certificate has been publicly logged.

RETURN VALUES
       SCT_validate() returns a negative integer if an internal error occurs,
       0 if the SCT fails validation, or 1 if the SCT passes validation.

       SCT_LIST_validate() returns a negative integer if an internal error
       occurs, 0 if any of SCTs fails validation, or 1 if they all pass
       validation.

       SCT_get_validation_status() returns the validation status of the SCT.
       If SCT_validate() or SCT_LIST_validate() have not been passed that SCT,
       the returned value will be SCT_VALIDATION_STATUS_NOT_SET.

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 Apache License 2.0 (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>.



3.0.12                            2023-05-07                   SCT_validate(3)