127 lines
2.9 KiB
Groff
127 lines
2.9 KiB
Groff
.\" @(#)des_crypt.3 2.1 88/08/11 4.0 RPCSRC; from 1.16 88/03/02 SMI;
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.TH DES_CRYPT 3 "6 October 1987"
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.SH NAME
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des_crypt, ecb_crypt, cbc_crypt, des_setparity \- fast DES encryption
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.SH SYNOPSIS
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.nf
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.B #include <des_crypt.h>
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.LP
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.B int ecb_crypt(key, data, datalen, mode)
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.B char *key;
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.B char *data;
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.B unsigned datalen;
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.B unsigned mode;
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.LP
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.B int cbc_crypt(key, data, datalen, mode, ivec)
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.B char *key;
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.B char *data;
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.B unsigned datalen;
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.B unsigned mode;
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.B char *ivec;
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.LP
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.B void des_setparity(key)
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.B char *key;
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.fi
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.SH DESCRIPTION
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.IX encryption cbc_crypt "" \fLcbc_crypt\fP
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.IX "des encryption" cbc_crypt "DES encryption" \fLcbc_crypt\fP
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.IX encryption des_setparity "" \fLdes_setparity\fP
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.IX "des encryption" des_setparity "DES encryption" \fLdes_setparity\fP
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.B ecb_crypt(\|)
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and
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.B cbc_crypt(\|)
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implement the
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.SM NBS
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.SM 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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.BR crypt (3).
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They also are able to utilize
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.SM DES
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hardware if it is available.
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.B ecb_crypt(\|)
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encrypts in
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.SM ECB
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(Electronic Code Book)
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mode, which encrypts blocks of data independently.
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.B cbc_crypt(\|)
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encrypts in
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.SM 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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.SM CBC
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mode protects against insertions, deletions and
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substitutions of blocks. Also, regularities in the clear text will
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not appear in the cipher text.
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.LP
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Here is how to use these routines. The first parameter,
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.IR 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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.SM DES
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is in the low bit of each byte, use
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.IR des_setparity .
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The second parameter,
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.IR data ,
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contains the data to be encrypted or decrypted. The
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third parameter,
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.IR datalen ,
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is the length in bytes of
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.IR data ,
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which must be a multiple of 8. The fourth parameter,
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.IR mode ,
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is formed by
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.SM OR\s0'ing
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together some things. For the encryption direction 'or' in either
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.SM DES_ENCRYPT
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or
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.SM DES_DECRYPT\s0.
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For software versus hardware
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encryption, 'or' in either
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.SM DES_HW
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or
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.SM DES_SW\s0.
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If
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.SM 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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.SM DESERR_NOHWDEVICE\s0.
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For
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.IR cbc_crypt ,
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the parameter
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.I ivec
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is the the 8-byte initialization
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vector for the chaining. It is updated to the next initialization
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vector upon return.
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.LP
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.SH "SEE ALSO"
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.BR des (1),
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.BR crypt (3)
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.SH DIAGNOSTICS
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.PD 0
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.TP 20
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.SM DESERR_NONE
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No error.
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.TP
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.SM DESERR_NOHWDEVICE
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Encryption succeeded, but done in software instead of the requested hardware.
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.TP
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.SM DESERR_HWERR
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An error occurred in the hardware or driver.
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.TP
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.SM DESERR_BADPARAM
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Bad parameter to routine.
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.PD
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.LP
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Given a result status
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.IR stat ,
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the macro
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.SM DES_FAILED\c
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.BR ( stat )
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is false only for the first two statuses.
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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 DES interface expected by
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Secure RPC.
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