SMIME_read_PKCS7(3)

     NAME
          SMIME_read_PKCS7 - parse S/MIME message.

     SYNOPSIS
          PKCS7 *SMIME_read_PKCS7(BIO *in, BIO **bcont);

     DESCRIPTION
          SMIME_read_PKCS7() 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 PKCS#7 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 PKCS7_verify() with the
          PKCS7_DETACHED flag set.

          Otherwise the type of the returned structure can be
          determined using PKCS7_type().

          To support future functionality if bcont is not NULL *bcont
          should be initialized to NULL. For example:

           BIO *cont = NULL;
           PKCS7 *p7;

           p7 = SMIME_read_PKCS7(in, &cont);


     BUGS
          The MIME parser used by SMIME_read_PKCS7() is somewhat
          primitive.  While it will handle most S/MIME messages more
          complex compound formats may not work.

          The parser assumes that the PKCS7 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_PKCS7() returns a valid PKCS7 structure or NULL
          is an error occurred. The error can be obtained from
          ERR_get_error(3).

     SEE ALSO
          ERR_get_error(3), PKCS7_type(3) SMIME_read_PKCS7(3),
          PKCS7_sign(3), PKCS7_verify(3), PKCS7_encrypt(3)
          PKCS7_decrypt(3)

     HISTORY
          SMIME_read_PKCS7() was added to OpenSSL 0.9.5