1=pod 2 3=head1 NAME 4 5X509_get0_signature, X509_get_signature_nid, X509_get0_tbs_sigalg, 6X509_REQ_get0_signature, X509_REQ_get_signature_nid, X509_CRL_get0_signature, 7X509_CRL_get_signature_nid, X509_get_signature_info, X509_SIG_INFO_get, 8X509_SIG_INFO_set - signature information 9 10=head1 SYNOPSIS 11 12 #include <openssl/x509.h> 13 14 void X509_get0_signature(const ASN1_BIT_STRING **psig, 15 const X509_ALGOR **palg, 16 const X509 *x); 17 int X509_get_signature_nid(const X509 *x); 18 const X509_ALGOR *X509_get0_tbs_sigalg(const X509 *x); 19 20 void X509_REQ_get0_signature(const X509_REQ *crl, 21 const ASN1_BIT_STRING **psig, 22 const X509_ALGOR **palg); 23 int X509_REQ_get_signature_nid(const X509_REQ *crl); 24 25 void X509_CRL_get0_signature(const X509_CRL *crl, 26 const ASN1_BIT_STRING **psig, 27 const X509_ALGOR **palg); 28 int X509_CRL_get_signature_nid(const X509_CRL *crl); 29 30 int X509_get_signature_info(X509 *x, int *mdnid, int *pknid, int *secbits, 31 uint32_t *flags); 32 33 int X509_SIG_INFO_get(const X509_SIG_INFO *siginf, int *mdnid, int *pknid, 34 int *secbits, uint32_t *flags); 35 void X509_SIG_INFO_set(X509_SIG_INFO *siginf, int mdnid, int pknid, 36 int secbits, uint32_t flags); 37 38=head1 DESCRIPTION 39 40X509_get0_signature() sets B<*psig> to the signature of B<x> and B<*palg> 41to the signature algorithm of B<x>. The values returned are internal 42pointers which B<MUST NOT> be freed up after the call. 43 44X509_get0_tbs_sigalg() returns the signature algorithm in the signed 45portion of B<x>. 46 47X509_get_signature_nid() returns the NID corresponding to the signature 48algorithm of B<x>. 49 50X509_REQ_get0_signature(), X509_REQ_get_signature_nid() 51X509_CRL_get0_signature() and X509_CRL_get_signature_nid() perform the 52same function for certificate requests and CRLs. 53 54X509_get_signature_info() retrieves information about the signature of 55certificate B<x>. The NID of the signing digest is written to B<*mdnid>, 56the public key algorithm to B<*pknid>, the effective security bits to 57B<*secbits> and flag details to B<*flags>. Any of the parameters can 58be set to B<NULL> if the information is not required. 59 60X509_SIG_INFO_get() and X509_SIG_INFO_set() get and set information 61about a signature in an B<X509_SIG_INFO> structure. They are only 62used by implementations of algorithms which need to set custom 63signature information: most applications will never need to call 64them. 65 66=head1 NOTES 67 68These functions provide lower level access to signatures in certificates 69where an application wishes to analyse or generate a signature in a form 70where X509_sign() et al is not appropriate (for example a non standard 71or unsupported format). 72 73The security bits returned by X509_get_signature_info() refers to information 74available from the certificate signature (such as the signing digest). In some 75cases the actual security of the signature is less because the signing 76key is less secure: for example a certificate signed using SHA-512 and a 771024 bit RSA key. 78 79=head1 RETURN VALUES 80 81X509_get_signature_nid(), X509_REQ_get_signature_nid() and 82X509_CRL_get_signature_nid() return a NID. 83 84X509_get0_signature(), X509_REQ_get0_signature() and 85X509_CRL_get0_signature() do not return values. 86 87X509_get_signature_info() returns 1 if the signature information 88returned is valid or 0 if the information is not available (e.g. 89unknown algorithms or malformed parameters). 90 91=head1 SEE ALSO 92 93L<d2i_X509(3)>, 94L<ERR_get_error(3)>, 95L<X509_CRL_get0_by_serial(3)>, 96L<X509_get_ext_d2i(3)>, 97L<X509_get_extension_flags(3)>, 98L<X509_get_pubkey(3)>, 99L<X509_get_subject_name(3)>, 100L<X509_get_version(3)>, 101L<X509_NAME_add_entry_by_txt(3)>, 102L<X509_NAME_ENTRY_get_object(3)>, 103L<X509_NAME_get_index_by_NID(3)>, 104L<X509_NAME_print_ex(3)>, 105L<X509_new(3)>, 106L<X509_sign(3)>, 107L<X509V3_get_d2i(3)>, 108L<X509_verify_cert(3)> 109 110=head1 HISTORY 111 112The 113X509_get0_signature() and X509_get_signature_nid() functions were 114added in OpenSSL 1.0.2. 115 116The 117X509_REQ_get0_signature(), X509_REQ_get_signature_nid(), 118X509_CRL_get0_signature() and X509_CRL_get_signature_nid() were 119added in OpenSSL 1.1.0. 120 121=head1 COPYRIGHT 122 123Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved. 124 125Licensed under the OpenSSL license (the "License"). You may not use 126this file except in compliance with the License. You can obtain a copy 127in the file LICENSE in the source distribution or at 128L<https://www.openssl.org/source/license.html>. 129 130=cut 131