@node en2814789modes
@section GOST 28147-89 cipher modes of operation

@table @asis
@item Type of standard
    Encryption and authentication modes
@item What modes are defined
    @itemize
        @item ECB
        @item CFB
        @item CTR
        @item MAC
    @end itemize
@item RFC
    @url{https://tools.ietf.org/html/rfc5830.html, 5830}
@end table

@strong{Features}:
@itemize
@item 28147-89 MAC is completely unusable:
    @itemize
        @item Reduced 16-round Magma cipher is used instead of 32 one.
        @item Authenticating data does not have neither padding, nor
        length specifying, so @code{MAC(0xDEAD) = MAC(0xDEAD00)}.
    @end itemize
@item Specified counter (CTR) mode increments counters with predefined
constants for 32-bit halves of the block. This differs from simpler
counter mode implementations.
@end itemize