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=head1 NAME

OSSL_CMP_MSG_get0_header,
OSSL_CMP_MSG_update_transactionID,
d2i_OSSL_CMP_MSG_bio,
i2d_OSSL_CMP_MSG_bio
- function(s) manipulating CMP messages

=head1 SYNOPSIS

  #include <openssl/cmp.h>

  OSSL_CMP_PKIHEADER *OSSL_CMP_MSG_get0_header(const OSSL_CMP_MSG *msg);
  int OSSL_CMP_MSG_update_transactionID(OSSL_CMP_CTX *ctx, OSSL_CMP_MSG *msg);
  OSSL_CMP_MSG *d2i_OSSL_CMP_MSG_bio(BIO *bio, OSSL_CMP_MSG **msg);
  int i2d_OSSL_CMP_MSG_bio(BIO *bio, const OSSL_CMP_MSG *msg);

=head1 DESCRIPTION

OSSL_CMP_MSG_get0_header() returns the header of the given CMP message.

OSSL_CMP_MSG_update_transactionID() updates the transactionID field
in the header of the given message according to the CMP_CTX.
This requires re-protecting the message (if it was protected).

d2i_OSSL_CMP_MSG_bio() parses an ASN.1-encoded OSSL_CMP_MSG from the BIO I<bio>.
It assigns a pointer to the new structure to I<*msg> if I<msg> is not NULL.

i2d_OSSL_CMP_MSG_bio() writes the OSSL_CMP_MSG I<msg> in ASN.1 encoding
to BIO I<bio>.

=head1 NOTES

CMP is defined in RFC 4210.

=head1 RETURN VALUES

OSSL_CMP_MSG_get0_header() returns the intended pointer value as described above
or NULL if the respective entry does not exist and on error.

d2i_OSSL_CMP_MSG_bio() returns the parsed message or NULL on error.

i2d_OSSL_CMP_MSG_bio() and OSSL_CMP_MSG_update_transactionID()
return 1 on success, 0 on error.

=head1 HISTORY

The OpenSSL CMP support was added in OpenSSL 3.0.

=head1 COPYRIGHT

Copyright 2007-2020 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
L<https://www.openssl.org/source/license.html>.

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