NAME

SMIME_write_CMS — convert CMS structure to S/MIME format

SYNOPSIS

#include <openssl/cms.h>

int
SMIME_write_CMS(BIO *out, CMS_ContentInfo *cms, BIO *data, int flags);

DESCRIPTION

SMIME_write_CMS() adds the appropriate MIME headers to the cms structure to produce an S/MIME message and writes it to out. If streaming is enabled, the content must be supplied in the data argument.

The following flags can be passed:

CMS_DETACHED

Use cleartext signing. This option only makes sense if cms is of the type SignedData and CMS_DETACHED was also set when it was created with CMS_sign(3).

If CMS_STREAM is not set, the data must be read twice: once to compute the signature in CMS_sign(3) and once to output the S/MIME message.

CMS_TEXT

Add MIME headers for type text/plain to the content. This only makes sense if CMS_DETACHED is also set.

CMS_STREAM

Perform streaming. This flag should only be set if CMS_STREAM was also passed to the function that created cms.

The content is output in BER format using indefinite length constructed encoding except in the case of SignedData with detached content where the content is absent and DER format is used.

RETURN VALUES

SMIME_write_CMS() returns 1 for success or 0 for failure.

SEE ALSO

CMS_ContentInfo_new(3), CMS_encrypt(3), CMS_sign(3), d2i_CMS_ContentInfo(3), ERR_get_error(3)

HISTORY

SMIME_write_CMS() first appeared in OpenSSL 0.9.8h and has been available since OpenBSD 6.7.

BUGS

SMIME_write_CMS() always base64 encodes CMS structures. There should be an option to disable this.