131 lines
2.6 KiB
Groff
131 lines
2.6 KiB
Groff
.\" @(#)des_crypt.3 2.1 88/08/11 4.0 RPCSRC; from 1.16 88/03/02 SMI;
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.\" $FreeBSD$
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.\"
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.Dd October 6, 1987
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.Dt DES_CRYPT 3
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.Os
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.Sh NAME
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.Nm des_crypt , ecb_crypt , cbc_crypt , des_setparity
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.Nd "fast DES encryption"
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In rpc/des_crypt.h
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.Ft int
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.Fn ecb_crypt "char *key" "char *data" "unsigned datalen" "unsigned mode"
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.Ft int
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.Fn cbc_crypt "char *key" "char *data" "unsigned datalen" "unsigned mode" "char *ivec"
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.Ft void
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.Fn des_setparity "char *key"
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.Sh DESCRIPTION
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The
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.Fn ecb_crypt
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and
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.Fn cbc_crypt
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functions
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implement the
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.Tn NBS
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.Tn DES
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(Data Encryption Standard).
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These routines are faster and more general purpose than
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.Xr crypt 3 .
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They also are able to utilize
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.Tn DES
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hardware if it is available.
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The
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.Fn ecb_crypt
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function
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encrypts in
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.Tn ECB
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(Electronic Code Book)
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mode, which encrypts blocks of data independently.
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The
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.Fn cbc_crypt
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function
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encrypts in
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.Tn CBC
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(Cipher Block Chaining)
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mode, which chains together
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successive blocks.
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.Tn CBC
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mode protects against insertions, deletions and
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substitutions of blocks.
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Also, regularities in the clear text will
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not appear in the cipher text.
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.Pp
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Here is how to use these routines.
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The first argument,
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.Fa key ,
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is the 8-byte encryption key with parity.
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To set the key's parity, which for
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.Tn DES
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is in the low bit of each byte, use
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.Fn des_setparity .
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The second argument,
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.Fa data ,
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contains the data to be encrypted or decrypted.
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The
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third argument,
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.Fa datalen ,
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is the length in bytes of
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.Fa data ,
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which must be a multiple of 8.
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The fourth argument,
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.Fa mode ,
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is formed by
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.Em OR Ns 'ing
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together some things.
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For the encryption direction
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.Em OR
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in either
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.Dv DES_ENCRYPT
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or
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.Dv DES_DECRYPT .
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For software versus hardware
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encryption,
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.Em OR
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in either
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.Dv DES_HW
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or
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.Dv DES_SW .
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If
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.Dv DES_HW
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is specified, and there is no hardware, then the encryption is performed
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in software and the routine returns
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.Er DESERR_NOHWDEVICE .
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For
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.Fn cbc_crypt ,
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the
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.Fa ivec
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argument
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is the 8-byte initialization
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vector for the chaining.
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It is updated to the next initialization
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vector upon return.
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.Sh ERRORS
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.Bl -tag -width [DESERR_NOHWDEVICE] -compact
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.It Bq Er DESERR_NONE
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No error.
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.It Bq Er DESERR_NOHWDEVICE
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Encryption succeeded, but done in software instead of the requested hardware.
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.It Bq Er DESERR_HWERROR
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An error occurred in the hardware or driver.
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.It Bq Er DESERR_BADPARAM
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Bad argument to routine.
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.El
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.Pp
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Given a result status
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.Va stat ,
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the macro
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.Fn DES_FAILED stat
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is false only for the first two statuses.
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.Sh SEE ALSO
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.\" .Xr des 1 ,
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.Xr crypt 3
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.Sh RESTRICTIONS
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These routines are not available in RPCSRC 4.0.
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This information is provided to describe the
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.Tn DES
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interface expected by
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Secure RPC.
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