reactos/dll/3rdparty/libtirpc/man/des_crypt.3t

   1 .\" @(#)des_crypt.3     2.1 88/08/11 4.0 RPCSRC; from 1.16 88/03/02 SMI;
   2 .\"
   3 .Dd October 6, 1987
   4 .Dt DES_CRYPT 3
   5 .Os
   6 .Sh NAME
   7 .Nm des_crypt , ecb_crypt , cbc_crypt , des_setparity
   8 .Nd "fast DES encryption"
   9 .Sh LIBRARY
  10 .Lb libc
  11 .Sh SYNOPSIS
  12 .In rpc/des_crypt.h
  13 .Ft int
  14 .Fn ecb_crypt "char *key" "char *data" "unsigned datalen" "unsigned mode"
  15 .Ft int
  16 .Fn cbc_crypt "char *key" "char *data" "unsigned datalen" "unsigned mode" "char *ivec"
  17 .Ft void
  18 .Fn des_setparity "char *key"
  19 .Sh DESCRIPTION
  20 The
  21 .Fn ecb_crypt
  22 and
  23 .Fn cbc_crypt
  24 functions
  25 implement the
  26 .Tn NBS
  27 .Tn DES
  28 (Data Encryption Standard).
  29 These routines are faster and more general purpose than
  30 .Xr crypt 3 .
  31 They also are able to utilize
  32 .Tn DES
  33 hardware if it is available.
  34 The
  35 .Fn ecb_crypt
  36 function
  37 encrypts in
  38 .Tn ECB
  39 (Electronic Code Book)
  40 mode, which encrypts blocks of data independently.
  41 The
  42 .Fn cbc_crypt
  43 function
  44 encrypts in
  45 .Tn CBC
  46 (Cipher Block Chaining)
  47 mode, which chains together
  48 successive blocks.
  49 .Tn CBC
  50 mode protects against insertions, deletions and
  51 substitutions of blocks.
  52 Also, regularities in the clear text will
  53 not appear in the cipher text.
  54 .Pp
  55 Here is how to use these routines.
  56 The first argument,
  57 .Fa key ,
  58 is the 8-byte encryption key with parity.
  59 To set the key's parity, which for
  60 .Tn DES
  61 is in the low bit of each byte, use
  62 .Fn des_setparity .
  63 The second argument,
  64 .Fa data ,
  65 contains the data to be encrypted or decrypted.
  66 The
  67 third argument,
  68 .Fa datalen ,
  69 is the length in bytes of
  70 .Fa data ,
  71 which must be a multiple of 8.
  72 The fourth argument,
  73 .Fa mode ,
  74 is formed by
  75 .Em OR Ns 'ing
  76 together some things.
  77 For the encryption direction
  78 .Em OR
  79 in either
  80 .Dv DES_ENCRYPT
  81 or
  82 .Dv DES_DECRYPT .
  83 For software versus hardware
  84 encryption,
  85 .Em OR
  86 in either
  87 .Dv DES_HW
  88 or
  89 .Dv DES_SW .
  90 If
  91 .Dv DES_HW
  92 is specified, and there is no hardware, then the encryption is performed
  93 in software and the routine returns
  94 .Er DESERR_NOHWDEVICE .
  95 For
  96 .Fn cbc_crypt ,
  97 the
  98 .Fa ivec
  99 argument
 100 is the 8-byte initialization
 101 vector for the chaining.
 102 It is updated to the next initialization
 103 vector upon return.
 104 .Sh ERRORS
 105 .Bl -tag -width [DESERR_NOHWDEVICE] -compact
 106 .It Bq Er DESERR_NONE
 107 No error.
 108 .It Bq Er DESERR_NOHWDEVICE
 109 Encryption succeeded, but done in software instead of the requested hardware.
 110 .It Bq Er DESERR_HWERR
 111 An error occurred in the hardware or driver.
 112 .It Bq Er DESERR_BADPARAM
 113 Bad argument to routine.
 114 .El
 115 .Pp
 116 Given a result status
 117 .Va stat ,
 118 the macro
 119 .Fn DES_FAILED stat
 120 is false only for the first two statuses.
 121 .Sh SEE ALSO
 122 .\" .Xr des 1 ,
 123 .Xr crypt 3
 124 .Sh RESTRICTIONS
 125 These routines are not available in RPCSRC 4.0.
 126 This information is provided to describe the
 127 .Tn DES
 128 interface expected by
 129 Secure RPC.