-DES_enc_read() is used to read I<len> bytes from file descriptor
-I<fd> into buffer I<buf>. The data being read from I<fd> is assumed to
-have come from DES_enc_write() and is decrypted using I<sched> for
-the key schedule and I<iv> for the initial vector.
-
-B<Warning:> The data format used by DES_enc_write() and DES_enc_read()
-has a cryptographic weakness: When asked to write more than MAXWRITE
-bytes, DES_enc_write() will split the data into several chunks that
-are all encrypted using the same IV. So don't use these functions
-unless you are sure you know what you do (in which case you might not
-want to use them anyway). They cannot handle non-blocking sockets.
-DES_enc_read() uses an internal state and thus cannot be used on
-multiple files.
-
-I<DES_rw_mode> is used to specify the encryption mode to use with
-DES_enc_read() and DES_end_write(). If set to I<DES_PCBC_MODE> (the
-default), DES_pcbc_encrypt is used. If set to I<DES_CBC_MODE>
-DES_cbc_encrypt is used.
-
-=head1 NOTES
-
-Single-key DES is insecure due to its short key size. ECB mode is
-not suitable for most applications; see L<DES_modes(7)|DES_modes(7)>.
-
-The L<evp(3)|evp(3)> library provides higher-level encryption functions.
-