1.\" @(#)des_crypt.3 2.1 88/08/11 4.0 RPCSRC; from 1.16 88/03/02 SMI; 2.\" $FreeBSD$ 3.\" 4.Dd October 6, 1987 5.Dt DES_CRYPT 3 6.Os 7.Sh NAME 8.Nm des_crypt , ecb_crypt , cbc_crypt , des_setparity 9.Nd "fast DES encryption" 10.Sh LIBRARY 11.Lb libc 12.Sh SYNOPSIS 13.In rpc/des_crypt.h 14.Ft int 15.Fn ecb_crypt "char *key" "char *data" "unsigned datalen" "unsigned mode" 16.Ft int 17.Fn cbc_crypt "char *key" "char *data" "unsigned datalen" "unsigned mode" "char *ivec" 18.Ft void 19.Fn des_setparity "char *key" 20.Sh DESCRIPTION 21The 22.Fn ecb_crypt 23and 24.Fn cbc_crypt 25functions 26implement the 27.Tn NBS 28.Tn DES 29(Data Encryption Standard). 30These routines are faster and more general purpose than 31.Xr crypt 3 . 32They also are able to utilize 33.Tn DES 34hardware if it is available. 35The 36.Fn ecb_crypt 37function 38encrypts in 39.Tn ECB 40(Electronic Code Book) 41mode, which encrypts blocks of data independently. 42The 43.Fn cbc_crypt 44function 45encrypts in 46.Tn CBC 47(Cipher Block Chaining) 48mode, which chains together 49successive blocks. 50.Tn CBC 51mode protects against insertions, deletions and 52substitutions of blocks. 53Also, regularities in the clear text will 54not appear in the cipher text. 55.Pp 56Here is how to use these routines. 57The first argument, 58.Fa key , 59is the 8-byte encryption key with parity. 60To set the key's parity, which for 61.Tn DES 62is in the low bit of each byte, use 63.Fn des_setparity . 64The second argument, 65.Fa data , 66contains the data to be encrypted or decrypted. 67The 68third argument, 69.Fa datalen , 70is the length in bytes of 71.Fa data , 72which must be a multiple of 8. 73The fourth argument, 74.Fa mode , 75is formed by 76.Em OR Ns 'ing 77together some things. 78For the encryption direction 79.Em OR 80in either 81.Dv DES_ENCRYPT 82or 83.Dv DES_DECRYPT . 84For software versus hardware 85encryption, 86.Em OR 87in either 88.Dv DES_HW 89or 90.Dv DES_SW . 91If 92.Dv DES_HW 93is specified, and there is no hardware, then the encryption is performed 94in software and the routine returns 95.Er DESERR_NOHWDEVICE . 96For 97.Fn cbc_crypt , 98the 99.Fa ivec 100argument 101is the 8-byte initialization 102vector for the chaining. 103It is updated to the next initialization 104vector upon return. 105.Sh ERRORS 106.Bl -tag -width [DESERR_NOHWDEVICE] -compact 107.It Bq Er DESERR_NONE 108No error. 109.It Bq Er DESERR_NOHWDEVICE 110Encryption succeeded, but done in software instead of the requested hardware. 111.It Bq Er DESERR_HWERR 112An error occurred in the hardware or driver. 113.It Bq Er DESERR_BADPARAM 114Bad argument to routine. 115.El 116.Pp 117Given a result status 118.Va stat , 119the macro 120.Fn DES_FAILED stat 121is false only for the first two statuses. 122.Sh SEE ALSO 123.\" .Xr des 1 , 124.Xr crypt 3 125.Sh RESTRICTIONS 126These routines are not available in RPCSRC 4.0. 127This information is provided to describe the 128.Tn DES 129interface expected by 130Secure RPC. 131