| Index: openssl/doc/crypto/CMS_sign_add1_signer.pod
|
| ===================================================================
|
| --- openssl/doc/crypto/CMS_sign_add1_signer.pod (revision 0)
|
| +++ openssl/doc/crypto/CMS_sign_add1_signer.pod (revision 0)
|
| @@ -0,0 +1,101 @@
|
| +=pod
|
| +
|
| +=head1 NAME
|
| +
|
| + CMS_sign_add1_signer, CMS_SignerInfo_sign - add a signer to a CMS_ContentInfo signed data structure.
|
| +
|
| +=head1 SYNOPSIS
|
| +
|
| + #include <openssl/cms.h>
|
| +
|
| + CMS_SignerInfo *CMS_sign_add1_signer(CMS_ContentInfo *cms, X509 *signcert, EVP_PKEY *pkey, const EVP_MD *md, unsigned int flags);
|
| +
|
| + int CMS_SignerInfo_sign(CMS_SignerInfo *si);
|
| +
|
| +
|
| +=head1 DESCRIPTION
|
| +
|
| +CMS_sign_add1_signer() adds a signer with certificate B<signcert> and private
|
| +key B<pkey> using message digest B<md> to CMS_ContentInfo SignedData
|
| +structure B<cms>.
|
| +
|
| +The CMS_ContentInfo structure should be obtained from an initial call to
|
| +CMS_sign() with the flag B<CMS_PARTIAL> set or in the case or re-signing a
|
| +valid CMS_ContentInfo SignedData structure.
|
| +
|
| +If the B<md> parameter is B<NULL> then the default digest for the public
|
| +key algorithm will be used.
|
| +
|
| +Unless the B<CMS_REUSE_DIGEST> flag is set the returned CMS_ContentInfo
|
| +structure is not complete and must be finalized either by streaming (if
|
| +applicable) or a call to CMS_final().
|
| +
|
| +The CMS_SignerInfo_sign() function will explicitly sign a CMS_SignerInfo
|
| +structure, its main use is when B<CMS_REUSE_DIGEST> and B<CMS_PARTIAL> flags
|
| +are both set.
|
| +
|
| +=head1 NOTES
|
| +
|
| +The main purpose of CMS_sign_add1_signer() is to provide finer control
|
| +over a CMS signed data structure where the simpler CMS_sign() function defaults
|
| +are not appropriate. For example if multiple signers or non default digest
|
| +algorithms are needed. New attributes can also be added using the returned
|
| +CMS_SignerInfo structure and the CMS attribute utility functions or the
|
| +CMS signed receipt request functions.
|
| +
|
| +Any of the following flags (ored together) can be passed in the B<flags>
|
| +parameter.
|
| +
|
| +If B<CMS_REUSE_DIGEST> is set then an attempt is made to copy the content
|
| +digest value from the CMS_ContentInfo structure: to add a signer to an existing
|
| +structure. An error occurs if a matching digest value cannot be found to copy.
|
| +The returned CMS_ContentInfo structure will be valid and finalized when this
|
| +flag is set.
|
| +
|
| +If B<CMS_PARTIAL> is set in addition to B<CMS_REUSE_DIGEST> then the
|
| +CMS_SignerInfo structure will not be finalized so additional attributes
|
| +can be added. In this case an explicit call to CMS_SignerInfo_sign() is
|
| +needed to finalize it.
|
| +
|
| +If B<CMS_NOCERTS> is set the signer's certificate will not be included in the
|
| +CMS_ContentInfo structure, the signer's certificate must still be supplied in
|
| +the B<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 CMS signedAttributes including the
|
| +signing time, the CMS content type and the supported list of ciphers in an
|
| +SMIMECapabilities attribute. If B<CMS_NOATTR> is set then no signedAttributes
|
| +will be used. If B<CMS_NOSMIMECAP> is set then just the SMIMECapabilities are
|
| +omitted.
|
| +
|
| +OpenSSL will by default identify signing certificates using issuer name
|
| +and serial number. If B<CMS_USE_KEYID> is set it will use the subject key
|
| +identifier value instead. An error occurs if the signing certificate does not
|
| +have a subject key identifier extension.
|
| +
|
| +If present the SMIMECapabilities attribute indicates support for the following
|
| +algorithms in preference order: 256 bit AES, Gost R3411-94, Gost 28147-89, 192
|
| +bit AES, 128 bit AES, triple DES, 128 bit RC2, 64 bit RC2, DES and 40 bit RC2.
|
| +If any of these algorithms is not available then it will not be included: for example the GOST algorithms will not be included if the GOST ENGINE is
|
| +not loaded.
|
| +
|
| +CMS_sign_add1_signer() returns an internal pointer to the CMS_SignerInfo
|
| +structure just added, this can be used to set additional attributes
|
| +before it is finalized.
|
| +
|
| +=head1 RETURN VALUES
|
| +
|
| +CMS_sign1_add_signers() returns an internal pointer to the CMS_SignerInfo
|
| +structure just added or NULL if an error occurs.
|
| +
|
| +=head1 SEE ALSO
|
| +
|
| +L<ERR_get_error(3)|ERR_get_error(3)>, L<CMS_sign(3)|CMS_sign(3)>,
|
| +L<CMS_final(3)|CMS_final(3)>,
|
| +
|
| +=head1 HISTORY
|
| +
|
| +CMS_sign_add1_signer() was added to OpenSSL 0.9.8
|
| +
|
| +=cut
|
|
|