cd6c3eeb |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: pkcs1.c,v 1.1 2000/07/01 11:17:38 mdw Exp $ |
4 | * |
5 | * PKCS#1 1.5 packing |
6 | * |
7 | * (c) 2000 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb 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 Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: pkcs1.c,v $ |
33 | * Revision 1.1 2000/07/01 11:17:38 mdw |
34 | * New support for PKCS#1 message encoding. |
35 | * |
36 | */ |
37 | |
38 | /*----- Header files ------------------------------------------------------*/ |
39 | |
40 | #include <string.h> |
41 | |
42 | #include <mLib/bits.h> |
43 | #include <mLib/dstr.h> |
44 | |
45 | #include "grand.h" |
46 | #include "pkcs1.h" |
47 | |
48 | /*----- Main code ---------------------------------------------------------*/ |
49 | |
50 | /* --- @pkcs1_cryptencode@ --- * |
51 | * |
52 | * Arguments: @const void *msg@ = pointer to message data |
53 | * @size_t msz@ = size of message data |
54 | * @void *buf@ = pointer to output buffer |
55 | * @size_t sz@ = size of the output buffer |
56 | * @void *p@ = pointer to PKCS1 parameter block |
57 | * |
58 | * Returns: Zero if all went well, negative on failure. |
59 | * |
60 | * Use: Implements the operation @EME-PKCS1-V1_5-ENCODE@, as defined |
61 | * in PKCS#1 v. 2.0 (RFC2437). |
62 | */ |
63 | |
64 | int pkcs1_cryptencode(const void *msg, size_t msz, void *buf, size_t sz, |
65 | void *p) |
66 | { |
67 | pkcs1 *pp = p; |
68 | grand *r = pp->r; |
69 | octet *q, *qq; |
70 | size_t i, n; |
71 | |
72 | /* --- Ensure that the buffer is sensibly sized --- */ |
73 | |
74 | if (pp->epsz + msz + 11 > sz) |
75 | return (-1); |
76 | |
77 | /* --- Fill in the buffer --- */ |
78 | |
79 | q = buf; |
80 | qq = q + sz; |
81 | *q++ = 0; |
82 | *q++ = 2; |
83 | n = sz - msz - pp->epsz - 3; |
84 | r->ops->fill(r, q, n); |
85 | for (i = 0; i < n; i++) { |
86 | if (*q == 0) |
87 | *q = r->ops->range(r, 255) + 1; |
88 | q++; |
89 | } |
90 | *q++ = 0; |
91 | memcpy(q, pp->ep, pp->epsz); |
92 | q += pp->epsz; |
93 | memcpy(q, msg, msz); |
94 | return (0); |
95 | } |
96 | |
97 | /* --- @pkcs1_cryptdecode@ --- * |
98 | * |
99 | * Arguments: @const void *buf@ = pointer to encoded buffer |
100 | * @size_t sz@ = size of the encoded buffer |
101 | * @dstr *d@ = pointer to destination string |
102 | * @void *p@ = pointer to PKCS1 parameter block |
103 | * |
104 | * Returns: The length of the output string if successful, negative on |
105 | * failure. |
106 | * |
107 | * Use: Implements the operation @EME-PKCS1-V1_5-DECODE@, as defined |
108 | * in PKCS#1 v. 2.0 (RFC2437). |
109 | */ |
110 | |
111 | int pkcs1_cryptdecode(const void *buf, size_t sz, dstr *d, void *p) |
112 | { |
113 | pkcs1 *pp = p; |
114 | const octet *q, *qq; |
115 | size_t n, i; |
116 | |
117 | /* --- Check the size of the block looks sane --- */ |
118 | |
119 | if (pp->epsz + 11 > sz) |
120 | return (-1); |
121 | q = buf; |
122 | qq = buf + sz; |
123 | |
124 | /* --- Ensure that the block looks OK --- */ |
125 | |
126 | if (*q++ != 0 || *q++ != 2) |
127 | return (-1); |
128 | |
129 | /* --- Check the nonzero padding --- */ |
130 | |
131 | i = 0; |
132 | while (*q != 0 && q < qq) |
133 | i++, q++; |
134 | if (i < 8 || q == qq) |
135 | return (-1); |
136 | q++; |
137 | |
138 | /* --- Check the encoding parameters --- */ |
139 | |
140 | if (memcmp(q, pp->ep, pp->epsz) != 0) |
141 | return (-1); |
142 | q += pp->epsz; |
143 | |
144 | /* --- Done --- */ |
145 | |
146 | n = qq - q; |
147 | dstr_putm(d, q, n); |
148 | return (n); |
149 | } |
150 | |
151 | /* --- @pkcs1_sigencode@ --- * |
152 | * |
153 | * Arguments: @const void *msg@ = pointer to message data |
154 | * @size_t msz@ = size of message data |
155 | * @void *buf@ = pointer to output buffer |
156 | * @size_t sz@ = size of the output buffer |
157 | * @void *p@ = pointer to PKCS1 parameter block |
158 | * |
159 | * Returns: Zero if all went well, negative on failure. |
160 | * |
161 | * Use: Implements the operation @EMSA-PKCS1-V1_5-ENCODE@, as defined |
162 | * in PKCS#1 v. 2.0 (RFC2437). |
163 | */ |
164 | |
165 | int pkcs1_sigencode(const void *msg, size_t msz, void *buf, size_t sz, |
166 | void *p) |
167 | { |
168 | pkcs1 *pp = p; |
169 | octet *q, *qq; |
170 | size_t n; |
171 | |
172 | /* --- Ensure that the buffer is sensibly sized --- */ |
173 | |
174 | if (pp->epsz + msz + 11 > sz) |
175 | return (-1); |
176 | |
177 | /* --- Fill in the buffer --- */ |
178 | |
179 | q = buf; |
180 | qq = q + sz; |
181 | *q++ = 0; |
182 | *q++ = 1; |
183 | n = sz - msz - pp->epsz - 3; |
184 | memset(q, 0xff, n); |
185 | q += n; |
186 | *q++ = 0; |
187 | memcpy(q, pp->ep, pp->epsz); |
188 | q += pp->epsz; |
189 | memcpy(q, msg, msz); |
190 | return (0); |
191 | } |
192 | |
193 | /* --- @pkcs1_sigdecode@ --- * |
194 | * |
195 | * Arguments: @const void *buf@ = pointer to encoded buffer |
196 | * @size_t sz@ = size of the encoded buffer |
197 | * @dstr *d@ = pointer to destination string |
198 | * @void *p@ = pointer to PKCS1 parameter block |
199 | * |
200 | * Returns: The length of the output string if successful, negative on |
201 | * failure. |
202 | * |
203 | * Use: Implements the operation @EMSA-PKCS1-V1_5-DECODE@, as defined |
204 | * in PKCS#1 v. 2.0 (RFC2437). |
205 | */ |
206 | |
207 | int pkcs1_sigdecode(const void *buf, size_t sz, dstr *d, void *p) |
208 | { |
209 | pkcs1 *pp = p; |
210 | const octet *q, *qq; |
211 | size_t i, n; |
212 | |
213 | /* --- Check the size of the block looks sane --- */ |
214 | |
215 | if (pp->epsz + 10 > sz) |
216 | return (-1); |
217 | q = buf; |
218 | qq = buf + sz; |
219 | |
220 | /* --- Ensure that the block looks OK --- */ |
221 | |
222 | if (*q++ != 0 || *q++ != 1) |
223 | return (-1); |
224 | |
225 | /* --- Check the padding --- */ |
226 | |
227 | i = 0; |
228 | while (*q == 0xff && q < qq) |
229 | i++, q++; |
230 | if (i < 8 || q == qq) |
231 | return (-1); |
232 | if (*q != 0) |
233 | return (-1); |
234 | q++; |
235 | |
236 | /* --- Check the encoding parameters --- */ |
237 | |
238 | if (memcmp(q, pp->ep, pp->epsz) != 0) |
239 | return (-1); |
240 | q += pp->epsz; |
241 | |
242 | /* --- Done --- */ |
243 | |
244 | n = qq - q; |
245 | dstr_putm(d, q, n); |
246 | return (n); |
247 | } |
248 | |
249 | /*----- That's all, folks -------------------------------------------------*/ |