[unix-history] / usr / src / foreign / src / libc / crypt.3

.\"	@(#)crypt.3	6.1.1.1 (Berkeley) 8/12/86
.\"
.TH CRYPT 3  "August 12, 1986"
.AT 3
.SH NAME
crypt, setkey, encrypt \- DES encryption
.SH SYNOPSIS
.nf
.B char *crypt(key, salt)
.B char *key, *salt;
.PP
.B setkey(key)
.B char *key;
.PP
.B encrypt(block, edflag)
.B char *block;
.fi
.SH DESCRIPTION
.I Crypt
is the password encryption routine.
It is based on the NBS Data Encryption Standard, with
variations intended (among other things) to frustrate use of hardware
implementations of the DES for key search.
.PP
The first argument to
.I crypt
is normally a user's typed password.
The second is a 2-character string chosen from the
set [a-zA-Z0-9./].
The
.I salt
string is used to perturb the DES algorithm in one of 4096
different ways, after which the password
is used as the key to encrypt repeatedly a constant string.
The returned value points to the encrypted password,
in the same alphabet as the salt.
The first two characters are the salt itself.
.PP
The other entries provide (rather primitive)
access to the actual DES algorithm.
The argument of
.I setkey
is a character array of length 64 containing only the characters
with numerical value 0 and 1.
If this string is divided into groups of 8,
the low-order bit in each group is ignored,
leading to a 56-bit key which is set into the machine.
.PP
The argument to the
.I encrypt
entry is likewise a character array of length 64
containing 0's and 1's.
The argument array is modified in place
to a similar array
representing the bits of the argument after having been
subjected to the DES algorithm using the key set by
.I setkey.
The
.I edflag
flag is ignored;
the argument can only be encrypted.
.SH "SEE ALSO"
passwd(1), passwd(5), login(1), getpass(3)
.SH BUGS
The return value
points to static data whose content is overwritten
by each call.
Commit	Line	Data
1c15e888	1	.\" @(#)crypt.3 6.1.1.1 (Berkeley) 8/12/86
0ce943ed	2	.\"
1c15e888	3	.TH CRYPT 3 "August 12, 1986"
0ce943ed KM	4	.AT 3
	5	.SH NAME
	6	crypt, setkey, encrypt \- DES encryption
	7	.SH SYNOPSIS
	8	.nf
	9	.B char *crypt(key, salt)
	10	.B char key, salt;
	11	.PP
	12	.B setkey(key)
	13	.B char *key;
	14	.PP
	15	.B encrypt(block, edflag)
	16	.B char *block;
	17	.fi
	18	.SH DESCRIPTION
	19	.I Crypt
	20	is the password encryption routine.
	21	It is based on the NBS Data Encryption Standard, with
	22	variations intended (among other things) to frustrate use of hardware
	23	implementations of the DES for key search.
	24	.PP
	25	The first argument to
	26	.I crypt
1f438fa4	27	is normally a user's typed password.
0ce943ed KM	28	The second is a 2-character string chosen from the
	29	set [a-zA-Z0-9./].
	30	The
	31	.I salt
	32	string is used to perturb the DES algorithm in one of 4096
	33	different ways, after which the password
	34	is used as the key to encrypt repeatedly a constant string.
	35	The returned value points to the encrypted password,
	36	in the same alphabet as the salt.
	37	The first two characters are the salt itself.
	38	.PP
	39	The other entries provide (rather primitive)
	40	access to the actual DES algorithm.
	41	The argument of
	42	.I setkey
	43	is a character array of length 64 containing only the characters
	44	with numerical value 0 and 1.
	45	If this string is divided into groups of 8,
	46	the low-order bit in each group is ignored,
	47	leading to a 56-bit key which is set into the machine.
	48	.PP
	49	The argument to the
	50	.I encrypt
	51	entry is likewise a character array of length 64
	52	containing 0's and 1's.
	53	The argument array is modified in place
	54	to a similar array
	55	representing the bits of the argument after having been
	56	subjected to the DES algorithm using the key set by
	57	.I setkey.
99187fa7	58	The
0ce943ed	59	.I edflag
99187fa7 KM	60	flag is ignored;
99187fa7 KM	61	the argument can only be encrypted.
0ce943ed KM	62	.SH "SEE ALSO"
	63	passwd(1), passwd(5), login(1), getpass(3)
	64	.SH BUGS
	65	The return value
	66	points to static data whose content is overwritten
	67	by each call.