NAME

        SMIME_read_CMS - parse S/MIME message.

SYNOPSIS

        #include <openssl/cms.h>

        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).

SEE ALSO

       ERR_get_error(3), CMS_type(3) SMIME_read_CMS(3), CMS_sign(3), CMS_verify(3),
       CMS_encrypt(3) CMS_decrypt(3)

HISTORY

       SMIME_read_CMS() was added to OpenSSL 0.9.8