NAME

       OSSL_CMP_MSG_http_perform - client-side HTTP(S) transfer of a CMP request-response pair

SYNOPSIS

        #include <openssl/cmp.h>

        OSSL_CMP_MSG *OSSL_CMP_MSG_http_perform(OSSL_CMP_CTX *ctx,
                                                const OSSL_CMP_MSG *req);

DESCRIPTION

       OSSL_CMP_MSG_http_perform() sends the given PKIMessage req to the CMP server specified in ctx and returns
       the result obtained from it.

       If OSSL_CMP_CTX_set_transfer_cb_arg(3) has been used to set the transfer callback argument then the
       provided pointer bios is taken as a two-element BIO array to use for the exchange with the server as
       described for the bio and rbio parameters of OSSL_HTTP_open(3).  For instance, the two BIO pointers may
       be equal and refer to a TLS connection, such as in BRSKI-AE where a pre-established TLS channel is reused
       for CMP.

       Otherwise the server specified via OSSL_CMP_CTX_set1_server(3) and optionally
       OSSL_CMP_CTX_set_serverPort(3) is contacted, where the default port is 80 for HTTP and 443 for HTTPS.
       The HTTP path (aka "CMP alias" in this context) to use is by default "/", otherwise the string specified
       via OSSL_CMP_CTX_set1_serverPath(3).  On success the function returns the server's response PKIMessage.

       The function makes use of any HTTP callback function set via OSSL_CMP_CTX_set_http_cb(3).  It respects
       any timeout value set via OSSL_CMP_CTX_set_option(3) with an OSSL_CMP_OPT_MSG_TIMEOUT argument.  It also
       respects any HTTP(S) proxy options set via OSSL_CMP_CTX_set1_proxy(3) and OSSL_CMP_CTX_set1_no_proxy(3)
       and the respective environment variables.  Proxying plain HTTP is supported directly, while using a proxy
       for HTTPS connections requires a suitable callback function such as OSSL_HTTP_proxy_connect(3).

NOTES

       CMP is defined in RFC 4210.  HTTP transfer for CMP is defined in RFC 6712.

RETURN VALUES

       OSSL_CMP_MSG_http_perform() returns the received CMP response message on success, else NULL.

SEE ALSO

       OSSL_CMP_CTX_new(3), OSSL_HTTP_open(3), and OSSL_HTTP_proxy_connect(3).

HISTORY

       The OpenSSL CMP support was added in OpenSSL 3.0.

       The OSSL_CMP_MSG_http_perform() use of transfer_cb_arg was added in OpenSSL 3.5.

COPYRIGHT

       Copyright 2007-2025 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>.

3.5.0                                              2025-06-04                    OSSL_CMP_MSG_HTTP_PERFORM(3SSL)