PKCS7_sign_add_signer, PKCS7_add_certificate, PKCS7_add_crl - add information to
PKCS7 structure
#include <openssl/pkcs7.h>
PKCS7_SIGNER_INFO *PKCS7_sign_add_signer(PKCS7 *p7, X509 *signcert,
EVP_PKEY *pkey, const EVP_MD *md, int flags);
int PKCS7_add_certificate(PKCS7 *p7, X509 *cert);
int PKCS7_add_crl(PKCS7 *p7, X509_CRL *crl);
PKCS7_sign_add_signer() adds a signer with certificate
signcert
and private key
pkey using message digest
md to a PKCS7 signed
data structure
p7.
The
PKCS7 structure should be obtained from an initial call to
PKCS7_sign() with the flag
PKCS7_PARTIAL set or in the case or
re-signing a valid PKCS#7 signed data structure.
If the
md parameter is NULL then the default digest for the public key
algorithm will be used.
Unless the
PKCS7_REUSE_DIGEST flag is set the returned
PKCS7
structure is not complete and must be finalized either by streaming (if
applicable) or a call to
PKCS7_final().
The main purpose of this function is to provide finer control over a PKCS#7
signed data structure where the simpler
PKCS7_sign() function defaults
are not appropriate. For example if multiple signers or non default digest
algorithms are needed.
Any of the following flags (ored together) can be passed in the
flags
parameter.
If
PKCS7_REUSE_DIGEST is set then an attempt is made to copy the content
digest value from the
PKCS7 structure: to add a signer to an existing
structure. An error occurs if a matching digest value cannot be found to copy.
The returned
PKCS7 structure will be valid and finalized when this flag
is set.
If
PKCS7_PARTIAL is set in addition to
PKCS7_REUSE_DIGEST then the
PKCS7_SIGNER_INO structure will not be finalized so additional
attributes can be added. In this case an explicit call to
PKCS7_SIGNER_INFO_sign() is needed to finalize it.
If
PKCS7_NOCERTS is set the signer's certificate will not be included in
the
PKCS7 structure, the signer's certificate must still be supplied in
the
signcert parameter though. This can reduce the size of the
signature if the signers certificate can be obtained by other means: for
example a previously signed message.
The signedData structure includes several PKCS#7 authenticatedAttributes
including the signing time, the PKCS#7 content type and the supported list of
ciphers in an SMIMECapabilities attribute. If
PKCS7_NOATTR is set then
no authenticatedAttributes will be used. If
PKCS7_NOSMIMECAP is set
then just the SMIMECapabilities are omitted.
If present the SMIMECapabilities attribute indicates support for the following
algorithms: triple DES, 128 bit RC2, 64 bit RC2, DES and 40 bit RC2. If any of
these algorithms is disabled then it will not be included.
PKCS7_sign_add_signers() returns an internal pointer to the
PKCS7_SIGNER_INFO structure just added, which can be used to set
additional attributes before it is finalized.
PKCS7_add_certificate() adds to the
PKCS7 structure
p7 the
certificate
cert, which may be an end-entity (signer) certificate or a
CA certificate useful for chain building. This is done internally by
PKCS7_sign_ex(3) and similar signing functions. It may have to be used
before calling
PKCS7_verify(3) in order to provide any missing
certificate(s) needed for verification.
PKCS7_add_crl() adds the CRL
crl to the
PKCS7 structure
p7. This may be called to provide certificate status information to be
included when signing or to use when verifying the
PKCS7 structure.
PKCS7_sign_add_signers() returns an internal pointer to the
PKCS7_SIGNER_INFO structure just added or NULL if an error occurs.
PKCS7_add_certificate() and
PKCS7_add_crl() return 1 on success, 0
on error.
ERR_get_error(3),
PKCS7_sign_ex(3),
PKCS7_final(3),
PKCS7_verify(3)
The
PPKCS7_sign_add_signer() function was added in OpenSSL 1.0.0.
Copyright 2007-2022 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
<
https://www.openssl.org/source/license.html>.