fcd15e0b |
1 | # -*-perl-*- |
2 | # |
3 | # $Id$ |
4 | # |
5 | # Elliptic curves |
6 | # |
7 | # (c) 2004 Straylight/Edgeware |
8 | # |
9 | |
10 | #----- Licensing notice ----------------------------------------------------- |
11 | # |
12 | # This file is part of the Perl interface to Catacomb. |
13 | # |
14 | # Catacomb/Perl is free software; you can redistribute it and/or modify |
15 | # it under the terms of the GNU General Public License as published by |
16 | # the Free Software Foundation; either version 2 of the License, or |
17 | # (at your option) any later version. |
18 | # |
19 | # Catacomb/Perl is distributed in the hope that it will be useful, |
20 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | # GNU General Public License for more details. |
23 | # |
24 | # You should have received a copy of the GNU General Public License |
25 | # along with Catacomb/Perl; if not, write to the Free Software Foundation, |
26 | # Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | |
28 | #----- Elliptic curves ------------------------------------------------------ |
29 | |
30 | package Catacomb::EC::Curve; |
31 | use Carp; |
32 | use Catacomb::Base; |
33 | use Catacomb::Cache; |
34 | use Catacomb::Field; |
35 | |
36 | $cache = Catacomb::Cache->new(); |
37 | |
38 | sub intern { |
39 | croak("Usage: Catacomb::EC::Curve::intern(c)") unless @_ == 1; |
40 | my ($c) = @_; |
41 | return $cache->intern($c); |
42 | } |
43 | |
44 | sub pt { |
45 | croak("Usage: Catacomb::EC::Curve::pt(c, [x, y | p])") |
46 | unless @_ >= 1 && @_ <= 3; |
47 | return Catacomb::EC::Pt->new(@_); |
48 | } |
49 | |
50 | sub a { |
51 | croak("Usage: Catacomb::EC::Curve::a(c)") unless @_ == 1; |
52 | my ($c) = @_; |
53 | return $c->field()->elt($c->_a()); |
54 | } |
55 | |
56 | sub b { |
57 | croak("Usage: Catacomb::EC::Curve::b(c)") unless @_ == 1; |
58 | my ($c) = @_; |
59 | return $c->field()->elt($c->_b()); |
60 | } |
61 | |
62 | sub inf { |
63 | croak("Usage: Catacomb::EC::Curve::inf(c)") unless @_ == 1; |
64 | return Catacomb::EC::Pt->new($_[0]); |
65 | } |
66 | |
67 | sub getraw { |
68 | croak("Usage: Catacomb::EC::Curve::getraw(c, s)") unless @_ == 2; |
69 | my ($c, $s) = @_; |
70 | my ($p, $rest) = $c->_getraw($s); |
71 | $p = Catacomb::EC::Pt->new($c, $p); |
72 | return !wantarray() ? $p : ($p, $rest); |
73 | } |
74 | |
75 | sub find { |
76 | croak("Usage: Catacomb::EC::Curve::find(c, x)") unless @_ == 2; |
77 | my ($c, $x) = @_; |
78 | my $p = $c->_find($x); |
79 | return undef unless defined $p; |
80 | return Catacomb::EC::Pt->new($c, $p); |
81 | } |
82 | |
83 | sub rand { |
84 | croak("Usage: Catacomb::EC::Curve::rand(c, [rng])") |
85 | unless @_ >= 1 && @_ <= 2; |
86 | my ($c, $rng) = @_; |
87 | $rng ||= $Catacomb::random; |
88 | my $p = $c->_rand($rng); |
89 | return Catacomb::EC::Pt->new($c, $p); |
90 | } |
91 | |
92 | sub mmul { |
93 | croak("Usage: Catacomb::EC::Curve::mmul(c, p_0, x_0, p_1, x_1, ...)") |
94 | unless @_ >= 3 && @_ % 2 == 1; |
95 | my $c = pop(@_); |
96 | my $i; |
97 | my @v = (); |
98 | my @r = (); |
99 | for ($i = 0; $i < @_; $i += 2) { |
100 | my $p = $_[$i]; |
101 | my $n = $_[$i + 1]; |
102 | if (UNIVERSAL::isa($p, Catacomb::EC::Pt)) { |
103 | $p->[1] == $c or croak("curve mismatch"); |
104 | @r or @r = @$p[1, 2, 3, 4]; |
105 | $p = $p->[0]; |
106 | } elsif (UNIVERSAL::isa($p, Catacomb::EC::Point)) { |
107 | $p = $c->in($p); |
108 | } else { |
109 | croak("not a curve point"); |
110 | } |
111 | push(@v, $p, $n); |
112 | } |
113 | unless (@r) { |
114 | my ($cr, $f, $fr); |
115 | ($c, $cr) = $c->intern(); |
116 | ($f, $fr) = $c->field()->intern(); |
117 | @r = ($c, $cr, $f, $fr); |
118 | } |
119 | return Catacomb::EC::Pt::_pt(immul($c, @v), $c, $cr, $f, $fr); |
120 | } |
121 | |
122 | sub getinfo { |
123 | croak("Usage: Catacomb::EC::Curve::getinfo(me, spec)") unless @_ == 2; |
124 | my ($me, $spec) = @_; |
125 | my ($c, $p, $r, $h) = _getinfo($me, $spec); |
126 | my $cr; |
127 | ($c, $cr) = $c->intern(); |
128 | return $c, $c->pt($p), $r, $h; |
129 | } |
130 | |
131 | sub ecgroup { |
132 | croak("Usage: Catacomb::EC::Curve::ecgroup(c, p, r, h)") unless @_ == 4; |
133 | return Catacomb::Group->ec(@_); |
134 | } |
135 | |
136 | #----- Elliptic curve points ------------------------------------------------ |
137 | |
138 | package Catacomb::EC::Point; |
139 | |
140 | sub tostring { |
141 | croak("Usage: Catacomb::EC::Point::tostring(p)") unless @_ == 1; |
142 | my ($p) = @_; |
143 | if ($p->atinfp()) { |
144 | return "inf"; |
145 | } else { |
146 | return "0x" . $p->x()->tostring(16) . ", 0x" . $p->y()->tostring(16); |
147 | } |
148 | } |
149 | |
150 | package Catacomb::EC::Pt; |
151 | use Carp; |
152 | use Catacomb::Base; |
153 | use Catacomb::Field; |
154 | |
155 | sub _pt { bless [@_], Catacomb::EC::Pt; } |
156 | |
157 | sub _convert { |
158 | my ($c, $cr, $f, $fr, $x) = @_; |
159 | if (UNIVERSAL::isa($x, Catacomb::EC::Pt)) { |
160 | croak("curve mismatch") unless $c == $x->[1]; |
161 | return $x; |
162 | } |
163 | if (UNIVERSAL::isa($x, Catacomb::EC::Point)) { |
164 | return _pt($x, $c, $cr, $f, $fr); |
165 | } |
166 | croak("can't convert to curve point"); |
167 | } |
168 | |
169 | sub new { |
170 | croak("Usage: Catacomb::EC::Pt::new(me, c, [x, y | p])") |
171 | unless @_ >= 2 && @_ <= 4; |
172 | my ($me, $c, $p); |
173 | if (@_ == 2) { |
174 | ($me, $c) = @_; |
175 | $p = Catacomb::EC::Point->new(); |
176 | } elsif (@_ == 3) { |
177 | ($me, $c, $p) = @_; |
178 | if (UNIVERSAL::isa($p, Catacomb::EC::Pt)) { |
179 | $p = $p->point(); |
180 | } elsif (!UNIVERSAL::isa($p, Catacomb::EC::Point)) { |
181 | croak("not a curve point"); |
182 | } |
183 | } else { |
184 | my ($x, $y); |
185 | ($me, $c, $x, $y) = @_; |
186 | $p = Catacomb::EC::Point->new($x, $y); |
187 | } |
188 | my ($cr, $f, $fr); |
189 | ($c, $cr) = $c->intern(); |
190 | ($f, $fr) = $c->field()->intern(); |
191 | return _pt($c->in($p), $c, $cr, $f, $fr); |
192 | } |
193 | |
194 | sub point { |
195 | croak("Usage: Catacomb::EC::Pt::point(p)") unless @_ == 1; |
196 | return $_[0][1]->out($_[0][0]); |
197 | } |
198 | |
199 | sub curve { |
200 | croak("Usage: Catacomb::EC::Pt::curve(p)") unless @_ == 1; |
201 | return $_[0][1]; |
202 | } |
203 | |
204 | sub field { |
205 | croak("Usage: Catacomb::EC::Pt::field(p)") unless @_ == 1; |
206 | return $_[0][3]; |
207 | } |
208 | |
209 | sub atinfp { |
210 | croak("Usage: Catacomb::EC::Pt::atinfp(p)") unless @_ == 1; |
211 | return $_[0]->point()->atinfp(); |
212 | } |
213 | |
214 | sub x { |
215 | croak("Usage: Catacomb::EC::Pt::x(p)") unless @_ == 1; |
216 | return $_[0][3]->elt($_[0]->point()->x()); |
217 | } |
218 | |
219 | sub y { |
220 | croak("Usage: Catacomb::EC::Pt::y(p)") unless @_ == 1; |
221 | return $_[0][3]->elt($_[0]->point()->y()); |
222 | } |
223 | |
224 | sub check { |
225 | croak("Usage: Catacomb::EC::Curve::check(c)") unless @_ == 1; |
226 | return $_[0][1]->check($_[0][0]); |
227 | } |
228 | |
229 | sub pt { |
230 | croak("Usage: Catacomb::EC::Pt::pt(pp, [x, y | p])") |
231 | unless @_ >= 1 && @_ <= 3; |
232 | my ($pp, $p); |
233 | if (@_ == 1) { |
234 | ($pp) = @_; |
235 | $p = Catacomb::EC::Point->new(); |
236 | } elsif (@_ == 2) { |
237 | ($pp, $p) = @_; |
238 | if (UNIVERSAL::isa($p, Catacomb::EC::Pt)) { |
239 | $p = $p->point(); |
240 | } elsif (!UNIVERSAL::isa($p, Catacomb::EC::Point)) { |
241 | croak("not a curve point"); |
242 | } |
243 | } else { |
244 | my ($x, $y); |
245 | ($pp, $x, $y) = @_; |
246 | $p = Catacomb::EC::Point->new($x, $y); |
247 | } |
248 | my (undef, $c, $cr, $f, $fr) = @$pp; |
249 | return _pt($c->in($p), $c, $cr, $f, $fr); |
250 | } |
251 | |
252 | sub _binop { |
253 | my ($op, $x, $y, $swap) = @_; |
254 | my (undef, $c, $cr, $f, $fr) = @$x; |
255 | $y = _convert($c, $cr, $f, $fr, $y); |
256 | my $z = $swap ? |
257 | &$op($c, $x->[0], $y->[0]) : |
258 | &$op($c, $y->[0], $x->[0]); |
259 | return _pt($z, $c, $cr, $f, $fr); |
260 | } |
261 | |
262 | sub _unop { |
263 | my ($op, $x) = @_; |
264 | my (undef, $c, $cr, $f, $fr) = @$x; |
265 | my $z = &$op($c, $x->[0]); |
266 | return _pt($z, $c, $cr, $f, $fr); |
267 | } |
268 | |
269 | sub _eq { |
270 | my ($x, $y) = @_; |
271 | my (undef, $c, $cr, $f, $fr) = @$x; |
272 | $y = _convert($c, $cr, $f, $fr, $y); |
273 | return Catacomb::EC::Point::eq($c->out($x), $c->out($y)); |
274 | } |
275 | |
276 | sub mul { |
277 | croak("Usage: Catacomb::EC::Pt::mul(p, n)") unless @_ == 2; |
278 | my ($p, $x) = @_; |
279 | my ($pp, $c, $cr, $f, $fr) = @$p; |
280 | return _pt($c->imul($pp, $x), $c, $cr, $f, $fr); |
281 | } |
282 | |
283 | use overload |
284 | '+' => sub { _binop(\&Catacomb::EC::Curve::iadd, @_); }, |
285 | '-' => sub { _binop(\&Catacomb::EC::Curve::isub, @_); }, |
286 | '*' => sub { mul($_[0], $_[1]); }, |
287 | '==' => sub { _eq(@_); }, |
288 | '!=' => sub { !_eq(@_); }, |
289 | 'eq' => sub { _eq(@_); }, |
290 | 'ne' => sub { !_eq(@_); }, |
291 | '""' => sub { $_[0]->point()->tostring(); }, |
292 | '0+' => sub { $_[0]->point()->x()->toint(); }, |
293 | 'neg' => sub { _unop(\&Catacomb::EC::Curve::ineg, @_); }; |
294 | |
295 | #----- That's all, folks ---------------------------------------------------- |