Attribute certificate printing functions

Add functions to print an attribute certificate.  Several
attribute value types defined by the RFC 5755 specification
are multi-field values (i.e ASN1_SEQUENCE rather than an ASN1_STRING
or similar format).  Currently those values are printed using
`ASN1_item_print`.  A more user-friendly output mechanism (maybe
similar to the i2r_ functions used for X509 extensions) could be
added in future.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15857)

2 files changed, 118 insertions, 0 deletions

diff --git a/doc/build.info b/doc/build.info
index da0e7a637f..43bb3c8a1d 100644
--- a/doc/build.info
+++ b/doc/build.info
@@ -2803,6 +2803,10 @@ DEPEND[html/man3/X509_ACERT_get0_holder_baseCertId.html]=man3/X509_ACERT_get0_ho
 GENERATE[html/man3/X509_ACERT_get0_holder_baseCertId.html]=man3/X509_ACERT_get0_holder_baseCertId.pod
 DEPEND[man/man3/X509_ACERT_get0_holder_baseCertId.3]=man3/X509_ACERT_get0_holder_baseCertId.pod
 GENERATE[man/man3/X509_ACERT_get0_holder_baseCertId.3]=man3/X509_ACERT_get0_holder_baseCertId.pod
+DEPEND[html/man3/X509_ACERT_print_ex.html]=man3/X509_ACERT_print_ex.pod
+GENERATE[html/man3/X509_ACERT_print_ex.html]=man3/X509_ACERT_print_ex.pod
+DEPEND[man/man3/X509_ACERT_print_ex.3]=man3/X509_ACERT_print_ex.pod
+GENERATE[man/man3/X509_ACERT_print_ex.3]=man3/X509_ACERT_print_ex.pod
 DEPEND[html/man3/X509_ALGOR_dup.html]=man3/X509_ALGOR_dup.pod
 GENERATE[html/man3/X509_ALGOR_dup.html]=man3/X509_ALGOR_dup.pod
 DEPEND[man/man3/X509_ALGOR_dup.3]=man3/X509_ALGOR_dup.pod
@@ -3636,6 +3640,7 @@ html/man3/UI_new.html \
 html/man3/X509V3_get_d2i.html \
 html/man3/X509V3_set_ctx.html \
 html/man3/X509_ACERT_get0_holder_baseCertId.html \
+html/man3/X509_ACERT_print_ex.html \
 html/man3/X509_ALGOR_dup.html \
 html/man3/X509_ATTRIBUTE.html \
 html/man3/X509_CRL_get0_by_serial.html \
@@ -4282,6 +4287,7 @@ man/man3/UI_new.3 \
 man/man3/X509V3_get_d2i.3 \
 man/man3/X509V3_set_ctx.3 \
 man/man3/X509_ACERT_get0_holder_baseCertId.3 \
+man/man3/X509_ACERT_print_ex.3 \
 man/man3/X509_ALGOR_dup.3 \
 man/man3/X509_ATTRIBUTE.3 \
 man/man3/X509_CRL_get0_by_serial.3 \
diff --git a/doc/man3/X509_ACERT_print_ex.pod b/doc/man3/X509_ACERT_print_ex.pod
new file mode 100644
index 0000000000..3a5e0c7a51
--- /dev/null
+++ b/doc/man3/X509_ACERT_print_ex.pod
@@ -0,0 +1,112 @@
+=pod
+
+=head1 NAME
+
+X509_ACERT_print_ex, X509_ACERT_print
+- X509_ACERT printing routines
+
+=head1 SYNOPSIS
+
+ #include <openssl/x509_acert.h>
+
+ int X509_ACERT_print(BIO *bp, X509_ACERT *acert);
+ int X509_ACERT_print_ex(BIO *bp, X509_ACERT *acert, unsigned long nmflags,
+                         unsigned long cflag);
+
+=head1 DESCRIPTION
+
+X509_ACERT_print_ex() prints a human readable version of the attribute
+certificate I<acert> to BIO I<bp>.
+
+The following data contained in the attribute certificate is printed
+in order:
+
+=over 4
+
+=item *
+
+The header text "Attribute certificate:" and "Data:" (X509_FLAG_NO_HEADER)
+
+= item *
+
+The attribute certificate version number as defined by the standard,
+followed in parentheses by the value contained in the version field in
+hexadecimal notation.  If the version number is not a valid value according
+to the specification, only the raw value is printed.
+See X509_ACERT_get_version(3) for details. (X509_FLAG_NO_VERSION)
+
+= item *
+
+The serial number of the attribute certificate (X509_FLAG_NO_SERIAL)
+
+= item *
+
+The identity of the holder of the attribute certificate. If the
+holder issuer name is present, the first GENERAL_NAME
+returned by X509_ACERT_get0_holder_entityName() is printed.
+If the holder baseCertificateId is present, the issuer name
+(printed with X509_NAME_print_ex) and serial number of the
+holder's certificate are displayed. (X509_FLAG_NO_SUBJECT)
+
+= item *
+
+The name of the attribute certificate issuer as returned from
+X509_ACERT_get0_issuerName() and printed using X509_NAME_print_ex().
+(X509_FLAG_NO_ISSUER)
+
+= item *
+
+The period of validity between the times returned from X509_ACERT_get0_notBefore()
+and  X509_ACERT_get0_notAfter().  The values are printed as a generalized times
+using ASN1_GENERALIZEDTIME_print(). (X509_FLAG_NO_VALIDITY)
+
+= item *
+
+The list of attributes contained in the attribute certificate.
+The attribute type is printed with i2a_ASN1_OBJECT().  String valued
+attributes are printed as raw string data. ASN1 encoded values are
+printed with ASN1_parse_dump().  (X509_FLAG_NO_ATTRIBUTES)
+
+= item *
+
+All X.509 extensions contained in the attribute certificate. (X509_FLAG_NO_EXTENSIONS)
+
+= item *
+
+The signature is printed with X509_signature_print(). (X509_FLAG_NO_SIGDUMP)
+
+If I<cflag> is specifies as X509_FLAG_COMPAT, all of the above data in the
+attribute certificate will be printed.
+
+The I<nmflags> flag determines the format used to output all fields printed using
+X509_NAME_print_ex(). See L<X509_NAME_print_ex(3)> for details.
+
+X509_ACERT_print() is equivalent to calling X509_ACERT_print_ex() with the
+I<nmflags> and I<cflags> set to XN_FLAG_COMPAT and X509_FLAG_COMPAT
+respectively.
+
+=back
+
+=head1 RETURN VALUES
+
+X509_ACERT_print_ex() X509_ACERT_print() return 1 for
+success and 0 for failure.
+
+=head1 SEE ALSO
+
+L<X509_NAME_print_ex(3)>
+
+=head1 HISTORY
+
+X509_ACERT_print() and X509_ACERT_print_ex() were added in OpenSSL 3.4.
+
+=head1 COPYRIGHT
+
+Copyright 2023 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>.
+
+=cut