CMS_ContentInfo *SMIME_read_CMS(BIO *in, BIO **bcont);
DESCRIPTION
SMIME_read_CMS() parses a message in S/MIME format.
in is a BIO to read the message
from.
If cleartext signing is used then the content is saved in a memory
bio which is written to *bcont,
otherwise *bcont is set to NULL.
The parsed CMS_ContentInfo structure is returned or NULL if an error
occurred.
NOTES
If *bcont is not NULL then the
message is clear text signed. *bcont
can then be passed to CMS_verify() with the CMS_DETACHED flag set.
Otherwise the type of the returned structure can be determined using
CMS_get0_type().
To support future functionality if bcont is not NULL *bcont should be initialized to NULL. For
example:
BIO *cont = NULL;
CMS_ContentInfo *cms;
cms = SMIME_read_CMS(in, &cont);
BUGS
The MIME parser used by SMIME_read_CMS() is somewhat primitive.
While it will handle most S/MIME messages more complex compound
formats may not work.
The parser assumes that the CMS_ContentInfo structure is always
base64 encoded and will not handle the case where it is in binary
format or uses quoted printable format.
The use of a memory BIO to hold the signed content limits the size of
message which can be processed due to memory restraints: a streaming
single pass option should be available.
RETURN VALUES
SMIME_read_CMS() returns a valid CMS_ContentInfo structure or NULL if an error occurred. The error can be
obtained from ERR_get_error(3).
