1=pod 2 3=head1 NAME 4 5CMS_SignerInfo_set1_signer_cert, 6CMS_get0_SignerInfos, CMS_SignerInfo_get0_signer_id, 7CMS_SignerInfo_get0_signature, CMS_SignerInfo_cert_cmp 8- CMS signedData signer functions 9 10=head1 SYNOPSIS 11 12 #include <openssl/cms.h> 13 14 STACK_OF(CMS_SignerInfo) *CMS_get0_SignerInfos(CMS_ContentInfo *cms); 15 16 int CMS_SignerInfo_get0_signer_id(CMS_SignerInfo *si, ASN1_OCTET_STRING **keyid, 17 X509_NAME **issuer, ASN1_INTEGER **sno); 18 ASN1_OCTET_STRING *CMS_SignerInfo_get0_signature(CMS_SignerInfo *si); 19 int CMS_SignerInfo_cert_cmp(CMS_SignerInfo *si, X509 *cert); 20 void CMS_SignerInfo_set1_signer_cert(CMS_SignerInfo *si, X509 *signer); 21 22=head1 DESCRIPTION 23 24The function CMS_get0_SignerInfos() returns all the CMS_SignerInfo structures 25associated with a CMS signedData structure. 26 27CMS_SignerInfo_get0_signer_id() retrieves the certificate signer identifier 28associated with a specific CMS_SignerInfo structure B<si>. Either the 29keyidentifier will be set in B<keyid> or B<both> issuer name and serial number 30in B<issuer> and B<sno>. 31 32CMS_SignerInfo_get0_signature() retrieves the signature associated with 33B<si> in a pointer to an ASN1_OCTET_STRING structure. This pointer returned 34corresponds to the internal signature value if B<si> so it may be read or 35modified. 36 37CMS_SignerInfo_cert_cmp() compares the certificate B<cert> against the signer 38identifier B<si>. It returns zero if the comparison is successful and non zero 39if not. 40 41CMS_SignerInfo_set1_signer_cert() sets the signers certificate of B<si> to 42B<signer>. 43 44=head1 NOTES 45 46The main purpose of these functions is to enable an application to lookup 47signers certificates using any appropriate technique when the simpler method 48of CMS_verify() is not appropriate. 49 50In typical usage and application will retrieve all CMS_SignerInfo structures 51using CMS_get0_SignerInfo() and retrieve the identifier information using 52CMS. It will then obtain the signer certificate by some unspecified means 53(or return and error if it cannot be found) and set it using 54CMS_SignerInfo_set1_signer_cert(). 55 56Once all signer certificates have been set CMS_verify() can be used. 57 58Although CMS_get0_SignerInfos() can return NULL if an error occurs B<or> if 59there are no signers this is not a problem in practice because the only 60error which can occur is if the B<cms> structure is not of type signedData 61due to application error. 62 63=head1 RETURN VALUES 64 65CMS_get0_SignerInfos() returns all CMS_SignerInfo structures, or NULL there 66are no signers or an error occurs. 67 68CMS_SignerInfo_get0_signer_id() returns 1 for success and 0 for failure. 69 70CMS_SignerInfo_cert_cmp() returns 0 for a successful comparison and non 71zero otherwise. 72 73CMS_SignerInfo_set1_signer_cert() does not return a value. 74 75Any error can be obtained from L<ERR_get_error(3)> 76 77=head1 SEE ALSO 78 79L<ERR_get_error(3)>, L<CMS_verify(3)> 80 81=head1 COPYRIGHT 82 83Copyright 2008-2018 The OpenSSL Project Authors. All Rights Reserved. 84 85Licensed under the Apache License 2.0 (the "License"). You may not use 86this file except in compliance with the License. You can obtain a copy 87in the file LICENSE in the source distribution or at 88L<https://www.openssl.org/source/license.html>. 89 90=cut 91