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DES_CRYPT(3) Linux Programmer's Manual DES_CRYPT(3)


     des_crypt,  ecb_crypt,  cbc_crypt, des_setparity, DES_FAILED - fast DES


     #include <rpc/des_crypt.h>
     int ecb_crypt(char *key, char *data, unsigned datalen,
                   unsigned mode);
     int cbc_crypt(char *key, char *data, unsigned datalen,
                   unsigned mode, char *ivec);
     void des_setparity(char *key);
     int DES_FAILED(int status);


     ecb_crypt() and cbc_crypt() implement  the  NBS  DES  (Data  Encryption
     Standard).   These  routines  are  faster and more general purpose than
     crypt(3).  They also are able to utilize DES hardware if it  is  avail-
     able.   ecb_crypt()  encrypts in ECB (Electronic Code Book) mode, which
     encrypts blocks of data independently.   cbc_crypt()  encrypts  in  CBC
     (Cipher  Block Chaining) mode, which chains together successive blocks.
     CBC mode protects against insertions, deletions  and  substitutions  of
     blocks.   Also,  regularities  in the clear text will not appear in the
     cipher text.
     Here is how to use these routines.  The first  argument,  key,  is  the
     8-byte  encryption key with parity.  To set the key's parity, which for
     DES is in the low bit of each byte, use  des_setparity().   The  second
     argument,  data,  contains  the data to be encrypted or decrypted.  The
     third argument, datalen, is the length in bytes of data, which must  be
     a  multiple  of  8.   The  fourth  argument,  mode,  is formed by ORing
     together some things.   For  the  encryption  direction  OR  in  either
     DES_ENCRYPT  or  DES_DECRYPT.  For software versus hardware encryption,
     OR in either DES_HW or DES_SW.  If DES_HW is specified, and there is no
     hardware,  then the encryption is performed in software and the routine
     returns DESERR_NOHWDEVICE.  For cbc_crypt(), the argument ivec  is  the
     8-byte  initialization  vector  for the chaining.  It is updated to the
     next initialization vector upon return.


     DESERR_NONE         No error.
     DESERR_NOHWDEVICE   Encryption succeeded, but done in software  instead
                         of the requested hardware.
     DESERR_HWERROR      An error occurred in the hardware or driver.
     DESERR_BADPARAM     Bad argument to routine.
     Given  a  result  status stat, the macro DES_FAILED(stat) is false only
     for the first two statuses.


     These functions are present in glibc 2.1 and later.


     For  an  explanation  of  the  terms  used   in   this   section,   see
     |Interface                 | Attribute     | Value   |
     |ecb_crypt(), cbc_crypt(), | Thread safety | MT-Safe |
     |des_setparity()           |               |         |


     4.3BSD.  Not in POSIX.1.


     des(1), crypt(3), xcrypt(3)


     This page is part of release 4.16 of the Linux  man-pages  project.   A
     description  of  the project, information about reporting bugs, and the
     latest    version    of    this    page,    can     be     found     at
                                2015-03-02                      DES_CRYPT(3)
/data/webs/external/dokuwiki/data/pages/man/des_crypt.txt · Last modified: 2019/05/17 09:47 by

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