$FreeBSD: releng/10.2/lib/libc/rpc/des_crypt.3 108087 2002-12-19 09:40:28Z ru $
.Dd October 6, 1987 .Dt DES_CRYPT 3 .Os .Sh NAME .Nm des_crypt , ecb_crypt , cbc_crypt , des_setparity .Nd "fast DES encryption" .Sh LIBRARY .Lb libc .Sh SYNOPSIS n rpc/des_crypt.h .Ft int .Fn ecb_crypt "char *key" "char *data" "unsigned datalen" "unsigned mode" .Ft int .Fn cbc_crypt "char *key" "char *data" "unsigned datalen" "unsigned mode" "char *ivec" .Ft void .Fn des_setparity "char *key" .Sh DESCRIPTION The .Fn ecb_crypt and .Fn cbc_crypt functions implement the .Tn NBS .Tn DES (Data Encryption Standard). These routines are faster and more general purpose than .Xr crypt 3 . They also are able to utilize .Tn DES hardware if it is available. The .Fn ecb_crypt function encrypts in .Tn ECB (Electronic Code Book) mode, which encrypts blocks of data independently. The .Fn cbc_crypt function encrypts in .Tn CBC (Cipher Block Chaining) mode, which chains together successive blocks. .Tn CBC mode protects against insertions, deletions and substitutions of blocks. Also, regularities in the clear text will not appear in the cipher text.
p Here is how to use these routines. The first argument, .Fa key , is the 8-byte encryption key with parity. To set the key's parity, which for .Tn DES is in the low bit of each byte, use .Fn des_setparity . The second argument, .Fa data , contains the data to be encrypted or decrypted. The third argument, .Fa datalen , is the length in bytes of .Fa data , which must be a multiple of 8. The fourth argument, .Fa mode , is formed by .Em OR Ns 'ing together some things. For the encryption direction .Em OR in either .Dv DES_ENCRYPT or .Dv DES_DECRYPT . For software versus hardware encryption, .Em OR in either .Dv DES_HW or .Dv DES_SW . If .Dv DES_HW is specified, and there is no hardware, then the encryption is performed in software and the routine returns .Er DESERR_NOHWDEVICE . For .Fn cbc_crypt , the .Fa ivec argument is the 8-byte initialization vector for the chaining. It is updated to the next initialization vector upon return. .Sh ERRORS l -tag -width [DESERR_NOHWDEVICE] -compact t Bq Er DESERR_NONE No error. t Bq Er DESERR_NOHWDEVICE Encryption succeeded, but done in software instead of the requested hardware. t Bq Er DESERR_HWERR An error occurred in the hardware or driver. t Bq Er DESERR_BADPARAM Bad argument to routine. .El
p
Given a result status
.Va stat ,
the macro
.Fn DES_FAILED stat
is false only for the first two statuses.
.Sh SEE ALSO
.Xr des 1 ,
.Xr crypt 3
.Sh RESTRICTIONS
These routines are not available in RPCSRC 4.0.
This information is provided to describe the
.Tn DES
interface expected by
Secure RPC.