5 PKCS7_sign - create a PKCS#7 signedData structure
9 PKCS7 *PKCS7_sign(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs, BIO *data, int flags);
13 PKCS7_sign() creates and returns a PKCS#7 signedData structure. B<signcert>
14 is the certificate to sign with, B<pkey> is the corresponsding private key.
15 B<certs> is an optional additional set of certificates to include in the
16 PKCS#7 structure (for example any intermediate CAs in the chain).
18 The data to be signed is read from BIO B<data>.
20 B<flags> is an optional set of flags.
24 Any of the following flags (ored together) can be passed in the B<flags> parameter.
26 Many S/MIME clients expect the signed content to include valid MIME headers. If
27 the B<PKCS7_TEXT> flag is set MIME headers for type B<text/plain> are prepended
30 If B<PKCS7_NOCERTS> is set the signer's certificate will not be included in the
31 PKCS7 structure, the signer's certificate must still be supplied in the B<signcert>
32 parameter though. This can reduce the size of the signature if the signers certificate
33 can be obtained by other means: for example a previously signed message.
35 The data being signed is included in the PKCS7 structure, unless B<PKCS7_DETACHED>
36 is set in which case it is omitted. This is used for PKCS7 detached signatures
37 which are used in S/MIME plaintext signed messages for example.
39 Normally the supplied content is translated into MIME canonical format (as required
40 by the S/MIME specifications) if B<PKCS7_BINARY> is set no translation occurs. This
41 option should be used if the supplied data is in binary format otherwise the translation
44 The signedData structure includes several PKCS#7 autenticatedAttributes including
45 the signing time, the PKCS#7 content type and the supported list of ciphers in
46 an SMIMECapabilities attribute. If B<PKCS7_NOATTR> is set then no authenticatedAttributes
47 will be used. If B<PKCS7_NOSMIMECAP> is set then just the SMIMECapabilities are
52 PKCS7_sign() returns either a valid PKCS7 structure or NULL if an error occurred.
53 The error can be obtained from ERR_get_error(3).
57 L<ERR_get_error(3)|ERR_get_error(3)>, L<PKCS7_verify(3)|PKCS7_verify(3)>