=pod =head1 NAME X509_get0_signature, X509_get_signature_nid, X509_get0_tbs_sigalg, X509_REQ_get0_signature, X509_REQ_get_signature_nid, X509_CRL_get0_signature, X509_CRL_get_signature_nid - signature information =head1 SYNOPSIS #include <openssl/x509.h> void X509_get0_signature(const ASN1_BIT_STRING **psig, const X509_ALGOR **palg, const X509 *x); int X509_get_signature_nid(const X509 *x); const X509_ALGOR *X509_get0_tbs_sigalg(const X509 *x); void X509_REQ_get0_signature(const X509_REQ *crl, const ASN1_BIT_STRING **psig, const X509_ALGOR **palg); int X509_REQ_get_signature_nid(const X509_REQ *crl); void X509_CRL_get0_signature(const X509_CRL *crl, const ASN1_BIT_STRING **psig, const X509_ALGOR **palg); int X509_CRL_get_signature_nid(const X509_CRL *crl); =head1 DESCRIPTION X509_get0_signature() sets B<*psig> to the signature of B<x> and B<*palg> to the signature algorithm of B<x>. The values returned are internal pointers which B<MUST NOT> be freed up after the call. X509_get0_tbs_sigalg() returns the signature algorithm in the signed portion of B<x>. X509_get_signature_nid() returns the NID corresponding to the signature algorithm of B<x>. X509_REQ_get0_signature(), X509_REQ_get_signature_nid() X509_CRL_get0_signature() and X509_CRL_get_signature_nid() perform the same function for certificate requests and CRLs. =head1 NOTES These functions provide lower level access to signatures in certificates where an application wishes to analyse or generate a signature in a form where X509_sign() et al is not appropriate (for example a non standard or unsupported format). =head1 RETURN VALUES X509_get_signature_nid(), X509_REQ_get_signature_nid() and X509_CRL_get_signature_nid() return a NID. X509_get0_signature(), X509_REQ_get0_signature() and X509_CRL_get0_signature() do not return values. =head1 SEE ALSO L<d2i_X509(3)>, L<ERR_get_error(3)>, L<X509_CRL_get0_by_serial(3)>, L<X509_get_ext_d2i(3)>, L<X509_get_extension_flags(3)>, L<X509_get_pubkey(3)>, L<X509_get_subject_name(3)>, L<X509_get_version(3)>, L<X509_NAME_add_entry_by_txt(3)>, L<X509_NAME_ENTRY_get_object(3)>, L<X509_NAME_get_index_by_NID(3)>, L<X509_NAME_print_ex(3)>, L<X509_new(3)>, L<X509_sign(3)>, L<X509V3_get_d2i(3)>, L<X509_verify_cert(3)> =head1 HISTORY X509_get0_signature() and X509_get_signature_nid() were first added to OpenSSL 1.0.2. X509_REQ_get0_signature(), X509_REQ_get_signature_nid(), X509_CRL_get0_signature() and X509_CRL_get_signature_nid() were first added to OpenSSL 1.1.0. =head1 COPYRIGHT Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved. Licensed under the OpenSSL license (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