34e4f738 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: group-parse.c,v 1.1 2004/04/01 12:50:09 mdw Exp $ |
4 | * |
5 | * Parse group description strings |
6 | * |
7 | * (c) 2004 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Trivial IP Encryption (TrIPE). |
13 | * |
14 | * TrIPE 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 | * TrIPE 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 TrIPE; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: group-parse.c,v $ |
32 | * Revision 1.1 2004/04/01 12:50:09 mdw |
33 | * Add cyclic group abstraction, with test code. Separate off exponentation |
34 | * functions for better static linking. Fix a buttload of bugs on the way. |
35 | * Generally ensure that negative exponents do inversion correctly. Add |
36 | * table of standard prime-field subgroups. (Binary field subgroups are |
37 | * currently unimplemented but easy to add if anyone ever finds a good one.) |
38 | * |
39 | */ |
40 | |
41 | /*----- Header files ------------------------------------------------------*/ |
42 | |
43 | #include "group.h" |
44 | #include "dh.h" |
45 | |
46 | /*----- Main code ---------------------------------------------------------*/ |
47 | |
48 | /* --- @group_parse@ --- * |
49 | * |
50 | * Arguments: @qd_parse *qd@ = quick-and-dirty parser |
51 | * |
52 | * Returns: Group pointer, or null for failure. |
53 | * |
54 | * Use: Parses a group description and returns the group. This has |
55 | * the form `TYPE { SPEC }' where TYPE is `prime' or `ec', and |
56 | * SPEC is the appropriate kind of group specification of the |
57 | * given type. |
58 | */ |
59 | |
60 | group *group_parse(qd_parse *qd) |
61 | { |
62 | group *g = 0; |
63 | |
64 | switch (qd_enum(qd, "prime,ec")) { |
65 | case 0: { |
66 | dh_param dp; |
67 | qd_delim(qd, '{'); |
68 | if (dh_parse(qd, &dp)) break; |
69 | qd_delim(qd, '}'); |
70 | g = group_prime(&dp); |
71 | dh_paramfree(&dp); |
72 | } break; |
73 | case 1: { |
74 | ec_info ei; |
75 | qd_delim(qd, '{'); |
76 | if (ec_infoparse(qd, &ei)) break; |
77 | qd_delim(qd, '}'); |
78 | g = group_ec(&ei); |
79 | } break; |
80 | } |
81 | return (g); |
82 | } |
83 | |
84 | /* --- @group_fromstring@ --- * |
85 | * |
86 | * Arguments: @const char *p@ = pointer to string to read |
87 | * @group **gg@ = where to put the group pointer |
88 | * |
89 | * Returns: Null if OK, or an error string. |
90 | * |
91 | * Use: Parses a group spec from a string, and returns the group. |
92 | */ |
93 | |
94 | const char *group_fromstring(const char *p, group **gg) |
95 | { |
96 | group *g; |
97 | qd_parse qd; |
98 | |
99 | qd.p = p; |
100 | qd.e = 0; |
101 | if ((g = group_parse(&qd)) == 0) return (qd.e); |
102 | if (!qd_eofp(&qd)) { G_DESTROYGROUP(g); return ("junk at end of string"); } |
103 | *gg = g; |
104 | return (0); |
105 | } |
106 | |
107 | /*----- That's all, folks -------------------------------------------------*/ |