X509_GET0_SIGNATURE(3)     Library Functions Manual     X509_GET0_SIGNATURE(3)

NAME
     X509_get0_signature, X509_REQ_get0_signature, X509_CRL_get0_signature,
     X509_get0_tbs_sigalg, X509_CRL_get0_tbs_sigalg, X509_get_signature_type,
     X509_get_signature_nid, X509_REQ_get_signature_nid,
     X509_CRL_get_signature_nid - signature information

SYNOPSIS
     #include <openssl/x509.h>

     void
     X509_get0_signature(const ASN1_BIT_STRING **psig,
         const X509_ALGOR **palg, const X509 *x);

     void
     X509_REQ_get0_signature(const X509_REQ *req,
         const ASN1_BIT_STRING **psig, const X509_ALGOR **palg);

     void
     X509_CRL_get0_signature(const X509_CRL *crl,
         const ASN1_BIT_STRING **psig, const X509_ALGOR **palg);

     const X509_ALGOR *
     X509_get0_tbs_sigalg(const X509 *x);

     const X509_ALGOR *
     X509_CRL_get0_tbs_sigalg(const X509_CRL *crl);

     int
     X509_get_signature_type(const X509 *x);

     int
     X509_get_signature_nid(const X509 *x);

     int
     X509_REQ_get_signature_nid(const X509_REQ *req);

     int
     X509_CRL_get_signature_nid(const X509_CRL *crl);

DESCRIPTION
     X509_get0_signature(), X509_REQ_get0_signature(), and
     X509_CRL_get0_signature() set *psig to the signature and *palg to the
     signature algorithm of x, req, or crl, respectively.
     X509_get0_tbs_sigalg() and X509_CRL_get0_tbs_sigalg() return the
     signature algorithm in the signed portion of x or crl, respectively.  The
     values returned are internal pointers that must not be freed by the
     caller.

     X509_get_signature_type() returns the base NID corresponding to the
     signature algorithm of x just like EVP_PKEY_base_id(3) does.

     X509_get_signature_nid(), X509_REQ_get_signature_nid(), and
     X509_CRL_get_signature_nid() return the NID corresponding to the
     signature algorithm of x, req, or crl, respectively, just like
     EVP_PKEY_id(3) does.

     These functions provide lower level access to the signature for cases
     where an application wishes to analyse or generate a signature in a form
     where X509_sign(3) is not appropriate, for example in a non-standard or
     unsupported format.

SEE ALSO
     EVP_PKEY_base_id(3), OBJ_obj2nid(3), X509_ALGOR_new(3),
     X509_CRL_get0_by_serial(3), X509_CRL_new(3), X509_get_pubkey(3),
     X509_get_subject_name(3), X509_get_version(3), X509_new(3),
     X509_REQ_new(3), X509_sign(3), X509_signature_dump(3),
     X509_verify_cert(3)

HISTORY
     X509_get_signature_type() first appeared in SSLeay 0.8.0 and has been
     available since OpenBSD 2.4.

     X509_get0_signature() and X509_get_signature_nid() first appeared in
     OpenSSL 1.0.2.  X509_REQ_get0_signature(), X509_CRL_get0_signature(),
     X509_get0_tbs_sigalg(), X509_REQ_get_signature_nid(), and
     X509_CRL_get_signature_nid() first appeared in OpenSSL 1.1.0.  All these
     functions have been available since OpenBSD 6.3.

     X509_CRL_get0_tbs_sigalg() first appeared in LibreSSL 3.7.1 and has been
     available since OpenBSD 7.3.

Linux 6.8.2-arch2-1             March 16, 2023             Linux 6.8.2-arch2-1