Index: openssl/doc/crypto/PKCS7_sign_add_signer.pod |
=================================================================== |
--- openssl/doc/crypto/PKCS7_sign_add_signer.pod (revision 0) |
+++ openssl/doc/crypto/PKCS7_sign_add_signer.pod (revision 0) |
@@ -0,0 +1,87 @@ |
+=pod |
+ |
+=head1 NAME |
+ |
+PKCS7_sign_add_signer - add a signer PKCS7 signed data structure. |
+ |
+=head1 SYNOPSIS |
+ |
+ #include <openssl/pkcs7.h> |
+ |
+ PKCS7_SIGNER_INFO *PKCS7_sign_add_signer(PKCS7 *p7, X509 *signcert, EVP_PKEY *pkey, const EVP_MD *md, int flags); |
+ |
+ |
+=head1 DESCRIPTION |
+ |
+PKCS7_sign_add_signer() adds a signer with certificate B<signcert> and private |
+key B<pkey> using message digest B<md> to a PKCS7 signed data structure |
+B<p7>. |
+ |
+The PKCS7 structure should be obtained from an initial call to PKCS7_sign() |
+with the flag B<PKCS7_PARTIAL> set or in the case or re-signing a valid PKCS7 |
+signed data structure. |
+ |
+If the B<md> parameter is B<NULL> then the default digest for the public |
+key algorithm will be used. |
+ |
+Unless the B<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(). |
+ |
+ |
+=head1 NOTES |
+ |
+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 B<flags> |
+parameter. |
+ |
+If B<PKCS7_REUSE_DIGEST> is set then an attempt is made to copy the content |
+digest value from the PKCS7 struture: 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 B<PKCS7_PARTIAL> is set in addition to B<PKCS7_REUSE_DIGEST> then the |
+B<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 B<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 |
+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 PKCS#7 autenticatedAttributes |
+including the signing time, the PKCS#7 content type and the supported list of |
+ciphers in an SMIMECapabilities attribute. If B<PKCS7_NOATTR> is set then no |
+authenticatedAttributes will be used. If B<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, this can be used to set additional attributes |
+before it is finalized. |
+ |
+=head1 RETURN VALUES |
+ |
+PKCS7_sign_add_signers() returns an internal pointer to the PKCS7_SIGNER_INFO |
+structure just added or NULL if an error occurs. |
+ |
+=head1 SEE ALSO |
+ |
+L<ERR_get_error(3)|ERR_get_error(3)>, L<PKCS7_sign(3)|PKCS7_sign(3)>, |
+L<PKCS7_final(3)|PKCS7_final(3)>, |
+ |
+=head1 HISTORY |
+ |
+PPKCS7_sign_add_signer() was added to OpenSSL 1.0.0 |
+ |
+=cut |