xref: /freebsd/lib/libmp/libmp.3 (revision 531c890b8aecbf157fe3491503b5ca62c0b01093)
1.\"
2.\" Copyright (c) 2001 Dima Dorfman.
3.\" All rights reserved.
4.\"
5.\" Redistribution and use in source and binary forms, with or without
6.\" modification, are permitted provided that the following conditions
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8.\" 1. Redistributions of source code must retain the above copyright
9.\"    notice, this list of conditions and the following disclaimer.
10.\" 2. Redistributions in binary form must reproduce the above copyright
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12.\"    documentation and/or other materials provided with the distribution.
13.\"
14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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25.\"
26.\" This manual page is based on the mp(3X) manual page from Sun Release
27.\" 4.1, dated 7 September 1989.  It's an old, crufty, and relatively ugly
28.\" manual page, but it does document what appears to be the "traditional"
29.\" libmp interface.
30.\"
31.\" $FreeBSD$
32.\"
33.\" See above for rationale for this date.
34.Dd September 7, 1989
35.Dt LIBMP 3
36.Os
37.Sh NAME
38.Nm libmp
39.Nd traditional BSD multiple precision integer arithmetic library
40.Sh SYNOPSIS
41.In mp.h
42.Pp
43Function prototypes are given in the main body of the text.
44.Pp
45Applications using this interface must be linked with
46.Fl l Ns Ar mp
47(this library)
48and
49.Fl l Ns Ar crypto
50.Pq Xr crypto 3 .
51.Sh DESCRIPTION
52.Bf -symbolic
53This interface is obsolete in favor of the
54.Xr crypto 3
55.Vt BIGNUM
56library.
57.Ef
58.Pp
59.Nm
60is the traditional
61.Bx
62multiple precision integer arithmetic library.
63It has a number of problems,
64and is unsuitable for use in any programs where reliability is a concern.
65It is provided here for compatibility only.
66.Pp
67These routines perform arithmetic on integers of arbitrary precision
68stored using the defined type
69.Vt MINT .
70Pointers to
71.Vt MINT
72are initialized using
73.Fn itom
74or
75.Fn xtom ,
76and must be recycled with
77.Fn mfree
78when they are no longer needed.
79Routines which store a result in one of their arguments expect that
80the latter has also been initialized prior to being passed to it.
81The following routines are defined and implemented:
82.Pp
83.Ft "MINT *" Ns
84.Fn itom "short n" ;
85.Pp
86.Ft "MINT *" Ns
87.Fn xtom "const char *s" ;
88.Pp
89.Ft "char *" Ns
90.Fn mtox "const MINT *mp" ;
91.Pp
92.Ft void
93.Fn mfree "MINT *mp" ;
94.Bd -ragged -offset indent
95.Fn itom
96returns an
97.Vt MINT
98with the value of
99.Fa n .
100.Fn xtom
101returns an
102.Vt MINT
103with the value of
104.Fa s ,
105which is treated to be in hexadecimal.
106The return values from
107.Fn itom
108and
109.Fn xtom
110must be released with
111.Fn mfree
112when they are no longer needed.
113.Fn mtox
114returns a null-terminated hexadecimal string having the value of
115.Fa mp ;
116its return value must be released with
117.Fn free
118.Pq Xr free 3
119when it is no longer needed.
120.Ed
121.Pp
122.Ft void
123.Fn madd "const MINT *mp1" "const MINT *mp2" "MINT *rmp" ;
124.Pp
125.Ft void
126.Fn msub "const MINT *mp1" "const MINT *mp2" "MINT *rmp" ;
127.Pp
128.Ft void
129.Fn mult "const MINT *mp1" "const MINT *mp2" "MINT *rmp" ;
130.Bd -ragged -offset indent
131.Fn madd ,
132.Fn msub ,
133and
134.Fn mult
135store the sum, difference, or product, respectively, of
136.Fa mp1
137and
138.Fa mp2
139in
140.Fa rmp .
141.Ed
142.Pp
143.Ft void
144.Fn mdiv "const MINT *nmp" "const MINT *dmp" "MINT *qmp" "MINT *rmp" ;
145.Pp
146.Ft void
147.Fn sdiv "const MINT *nmp" "short d" "MINT *qmp" "short *ro" ;
148.Bd -ragged -offset indent
149.Fn mdiv
150computes the quotient and remainder of
151.Fa nmp
152and
153.Fa dmp
154and stores the result in
155.Fa qmp
156and
157.Fa rmp ,
158respectively.
159.Fn sdiv
160is similar to
161.Fn mdiv
162except the divisor
163.Fa ( dmp
164or
165.Fa d )
166and remainder
167.Fa ( rmp
168or
169.Fa ro )
170are ordinary integers.
171.Ed
172.Pp
173.Ft void
174.Fn pow "const MINT *bmp" "const MINT *emp" "const MINT *mmp" "MINT *rmp" ;
175.Pp
176.Ft void
177.Fn rpow "const MINT *bmp" "short e" "MINT *rmp" ;
178.Bd -ragged -offset indent
179.Fn rpow
180computes the result of
181.Fa bmp
182raised to the
183.Fa emp Ns th
184power and reduced modulo
185.Fa mmp ;
186the result is stored in
187.Fa rmp .
188.Fn pow
189computes the result of
190.Fa bmp
191raised to the
192.Fa e Ns th
193power and stores the result in
194.Fa rmp .
195.Ed
196.Pp
197.Ft void
198.Fn min "MINT *mp" ;
199.Pp
200.Ft void
201.Fn mout "const MINT *mp" ;
202.Bd -ragged -offset indent
203.Fn min
204reads a line from standard input, tries to interpret it as a decimal
205number, and if successful, stores the result in
206.Fa mp .
207.Fn mout
208prints the value, in decimal, of
209.Fa mp
210to standard output (without a trailing newline).
211.Ed
212.Pp
213.Ft void
214.Fn gcd "const MINT *mp1" "const MINT *mp2" "MINT *rmp" ;
215.Bd -ragged -offset indent
216.Fn gcd
217computes the greatest common divisor of
218.Fa mp1
219and
220.Fa mp2
221and stores the result in
222.Fa rmp .
223.Ed
224.Pp
225.Ft int
226.Fn mcmp "const MINT *mp1" "const MINT *mp2" ;
227.Bd -ragged -offset indent
228.Fa mcmp
229compares the values of
230.Fa mp1
231and
232.Fa mp2
233and returns
2340 if the two values are equal,
235a value greater than 0 if
236.Fa mp1
237is greater than
238.Fa mp2 ,
239and a value less than 0 if
240.Fa mp2
241is greater than
242.Fa mp1 .
243.Ed
244.Pp
245.Ft void
246.Fn move "const MINT *smp" "MINT *tmp" ;
247.Bd -ragged -offset indent
248.Fn move
249copies the value of
250.Fa smp
251to
252.Fa tmp
253(both values must be initialized).
254.Ed
255.Pp
256.Ft void
257.Fn msqrt "const MINT *nmp" "MINT *xmp" "MINT *rmp" ;
258.Bd -ragged -offset indent
259.Fn msqrt
260computes the square root and remainder of
261.Fa nmp
262and stores them in
263.Fa xmp
264and
265.Fa rmp ,
266respectively.
267.Ed
268.Sh IMPLEMENTATION NOTES
269This version of
270.Nm
271is implemented in terms of the
272.Xr crypto 3
273.Vt BIGNUM
274library.
275.Sh DIAGNOSTICS
276Running out of memory or illegal operations result in error messages
277on standard error and a call to
278.Xr abort 3 .
279.Sh SEE ALSO
280.Xr abort 3 ,
281.Xr bn 3 ,
282.Xr crypto 3 ,
283.Xr free 3 ,
284.Xr malloc 3 ,
285.Xr math 3
286.Sh HISTORY
287A
288.Nm
289library appeared in
290.Bx 4.3 .
291.Fx 2.2
292shipped with a
293.Nm
294implemented in terms of
295.Nm libgmp .
296This implementation appeared in
297.Fx 5.0 .
298.Sh BUGS
299The
300.Fn pow
301routine exists in both
302.Nm libmp
303and
304.Nm libm
305with incompatible semantics.
306.Pp
307Errors are reported via output to standard error and abnormal
308program termination instead of via return values.
309The application cannot control this behavior.
310.Pp
311It is not clear whether the string returned by
312.Fn mtox
313may be written to by the caller.
314This implementation allows it, but others may not.
315Ideally,
316.Fn mtox
317would take a pointer to a buffer to fill in.
318.Pp
319It is not clear whether using the same variable as both source and
320destination in a single invocation is permitted.
321Some of the calls in this implementation allow this, while others
322do not.
323