NAME

       OSSL_ESS_signing_cert_new_init, OSSL_ESS_signing_cert_v2_new_init,
       OSSL_ESS_check_signing_certs - Enhanced Security Services (ESS) functions

SYNOPSIS

        #include <openssl/ess.h>

        ESS_SIGNING_CERT *OSSL_ESS_signing_cert_new_init(const X509 *signcert,
                                                         const STACK_OF(X509) *certs,
                                                         int set_issuer_serial);
        ESS_SIGNING_CERT_V2 *OSSL_ESS_signing_cert_v2_new_init(const EVP_MD *hash_alg,
                                                               const X509 *signcert,
                                                               const
                                                               STACK_OF(X509) *certs,
                                                               int set_issuer_serial);
        int OSSL_ESS_check_signing_certs(const ESS_SIGNING_CERT *ss,
                                         const ESS_SIGNING_CERT_V2 *ssv2,
                                         const STACK_OF(X509) *chain,
                                         int require_signing_cert);

DESCRIPTION

       OSSL_ESS_signing_cert_new_init() generates a new ESS_SIGNING_CERT structure referencing
       the given signcert and any given further certs using their SHA-1 fingerprints.  If
       set_issuer_serial is nonzero then also the issuer and serial number of signcert are
       included in the ESS_CERT_ID as the issuerSerial field.  For all members of certs the
       issuerSerial field is always included.

       OSSL_ESS_signing_cert_v2_new_init() is the same as OSSL_ESS_signing_cert_new_init() except
       that it uses the given hash_alg and generates a ESS_SIGNING_CERT_V2 structure with
       ESS_CERT_ID_V2 elements.

       OSSL_ESS_check_signing_certs() checks if the validation chain chain contains the
       certificates required by the identifiers given in ss and/or ssv2.  If require_signing_cert
       is nonzero, ss or ssv2 must not be NULL.  If both ss and ssv2 are not NULL, they are
       evaluated independently.  The list of certificate identifiers in ss is of type
       ESS_CERT_ID, while the list contained in ssv2 is of type ESS_CERT_ID_V2.  As far as these
       lists are present, they must be nonempty.  The certificate identified by their first entry
       must be the first element of chain, i.e. the signer certificate.  Any further certficates
       referenced in the list must also be found in chain.  The matching is done using the given
       certificate hash algorithm and value.  In addition to the checks required by RFCs 2624 and
       5035, if the issuerSerial field is included in an ESSCertID or ESSCertIDv2 it must match
       the certificate issuer and serial number attributes.

NOTES

       ESS has been defined in RFC 2634, which has been updated in RFC 5035 (ESS version 2) to
       support hash algorithms other than SHA-1.  This is used for TSP (RFC 3161) and CAdES-BES
       (informational RFC 5126).

RETURN VALUES

       OSSL_ESS_signing_cert_new_init() and OSSL_ESS_signing_cert_v2_new_init() return a pointer
       to the new structure or NULL on malloc failure.

       OSSL_ESS_check_signing_certs() returns 1 on success, 0 if a required certificate cannot be
       found, -1 on other error.

SEE ALSO

       TS_VERIFY_CTX_set_certs(3), CMS_verify(3)

HISTORY

       OSSL_ESS_signing_cert_new_init(), OSSL_ESS_signing_cert_v2_new_init(), and
       OSSL_ESS_check_signing_certs() were added in OpenSSL 3.0.

COPYRIGHT

       Copyright 2021 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>.