5 Author: Pekka Riikonen <priikone@silcnet.org>
7 Copyright (C) 2000 - 2001 Pekka Riikonen
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
22 #include "silcincludes.h"
24 /* Encodes Key Exchange Start Payload into a SILC Buffer to be sent
27 SilcSKEStatus silc_ske_payload_start_encode(SilcSKE ske,
28 SilcSKEStartPayload *payload,
29 SilcBuffer *return_buffer)
34 SILC_LOG_DEBUG(("Encoding KE Start Payload"));
37 return SILC_SKE_STATUS_ERROR;
39 buf = silc_buffer_alloc(payload->len);
41 return SILC_SKE_STATUS_OUT_OF_MEMORY;
42 silc_buffer_pull_tail(buf, SILC_BUFFER_END(buf));
44 /* Encode the payload */
45 ret = silc_buffer_format(buf,
46 SILC_STR_UI_CHAR(0), /* RESERVED field */
47 SILC_STR_UI_CHAR(payload->flags),
48 SILC_STR_UI_SHORT(payload->len),
49 SILC_STR_UI_XNSTRING(payload->cookie,
51 SILC_STR_UI_SHORT(payload->version_len),
52 SILC_STR_UI_XNSTRING(payload->version,
53 payload->version_len),
54 SILC_STR_UI_SHORT(payload->ke_grp_len),
55 SILC_STR_UI_XNSTRING(payload->ke_grp_list,
57 SILC_STR_UI_SHORT(payload->pkcs_alg_len),
58 SILC_STR_UI_XNSTRING(payload->pkcs_alg_list,
59 payload->pkcs_alg_len),
60 SILC_STR_UI_SHORT(payload->enc_alg_len),
61 SILC_STR_UI_XNSTRING(payload->enc_alg_list,
62 payload->enc_alg_len),
63 SILC_STR_UI_SHORT(payload->hash_alg_len),
64 SILC_STR_UI_XNSTRING(payload->hash_alg_list,
65 payload->hash_alg_len),
66 SILC_STR_UI_SHORT(payload->hmac_alg_len),
67 SILC_STR_UI_XNSTRING(payload->hmac_alg_list,
68 payload->hmac_alg_len),
69 SILC_STR_UI_SHORT(payload->comp_alg_len),
70 SILC_STR_UI_XNSTRING(payload->comp_alg_list,
71 payload->comp_alg_len),
74 silc_buffer_free(buf);
75 return SILC_SKE_STATUS_ERROR;
78 /* Return the encoded buffer */
81 SILC_LOG_HEXDUMP(("KE Start Payload"), buf->data, buf->len);
83 return SILC_SKE_STATUS_OK;
86 /* Parses the Key Exchange Start Payload. Parsed data is returned
87 to allocated payload structure. */
90 silc_ske_payload_start_decode(SilcSKE ske,
92 SilcSKEStartPayload **return_payload)
94 SilcSKEStartPayload *payload;
95 SilcSKEStatus status = SILC_SKE_STATUS_ERROR;
99 SILC_LOG_DEBUG(("Decoding Key Exchange Start Payload"));
101 SILC_LOG_HEXDUMP(("KE Start Payload"), buffer->data, buffer->len);
103 payload = silc_calloc(1, sizeof(*payload));
105 return SILC_SKE_STATUS_OUT_OF_MEMORY;
106 payload->cookie_len = SILC_SKE_COOKIE_LEN;
108 /* Parse start of the payload */
110 silc_buffer_unformat(buffer,
111 SILC_STR_UI_CHAR(&tmp), /* RESERVED Field */
112 SILC_STR_UI_CHAR(&payload->flags),
113 SILC_STR_UI_SHORT(&payload->len),
114 SILC_STR_UI_XNSTRING_ALLOC(&payload->cookie,
115 payload->cookie_len),
116 SILC_STR_UI16_NSTRING_ALLOC(&payload->version,
117 &payload->version_len),
118 SILC_STR_UI16_NSTRING_ALLOC(&payload->ke_grp_list,
119 &payload->ke_grp_len),
120 SILC_STR_UI16_NSTRING_ALLOC(&payload->pkcs_alg_list,
121 &payload->pkcs_alg_len),
122 SILC_STR_UI16_NSTRING_ALLOC(&payload->enc_alg_list,
123 &payload->enc_alg_len),
124 SILC_STR_UI16_NSTRING_ALLOC(&payload->hash_alg_list,
125 &payload->hash_alg_len),
126 SILC_STR_UI16_NSTRING_ALLOC(&payload->hmac_alg_list,
127 &payload->hmac_alg_len),
128 SILC_STR_UI16_NSTRING_ALLOC(&payload->comp_alg_list,
129 &payload->comp_alg_len),
132 SILC_LOG_ERROR(("Malformed KE Start Payload"));
133 status = SILC_SKE_STATUS_BAD_PAYLOAD;
138 SILC_LOG_DEBUG(("Bad reserved field"));
139 SILC_LOG_ERROR(("Bad RESERVED field in KE Start Payload"));
140 status = SILC_SKE_STATUS_BAD_RESERVED_FIELD;
144 if (payload->len != buffer->len) {
145 SILC_LOG_ERROR(("Garbage after KE Start Payload"));
146 status = SILC_SKE_STATUS_BAD_PAYLOAD_LENGTH;
150 /* Check for mandatory fields */
151 if (!payload->cookie || !payload->version_len ||
152 !payload->ke_grp_len || !payload->pkcs_alg_len ||
153 !payload->enc_alg_len || !payload->hash_alg_len ||
154 !payload->hmac_alg_len) {
155 SILC_LOG_ERROR(("KE Start Payload is missing mandatory fields"));
156 status = SILC_SKE_STATUS_BAD_PAYLOAD;
160 /* Return the payload */
161 *return_payload = payload;
163 return SILC_SKE_STATUS_OK;
166 silc_ske_payload_start_free(payload);
168 ske->status = status;
172 /* Free's Start Payload */
174 void silc_ske_payload_start_free(SilcSKEStartPayload *payload)
177 silc_free(payload->cookie);
178 silc_free(payload->version);
179 silc_free(payload->ke_grp_list);
180 silc_free(payload->pkcs_alg_list);
181 silc_free(payload->enc_alg_list);
182 silc_free(payload->hash_alg_list);
183 silc_free(payload->hmac_alg_list);
184 silc_free(payload->comp_alg_list);
189 /* Encodes Key Exchange Payload into a SILC Buffer to be sent to the other
192 SilcSKEStatus silc_ske_payload_ke_encode(SilcSKE ske,
193 SilcSKEKEPayload *payload,
194 SilcBuffer *return_buffer)
197 unsigned char *x_str;
201 SILC_LOG_DEBUG(("Encoding KE Payload"));
204 return SILC_SKE_STATUS_ERROR;
206 if (ske->start_payload &&
207 ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL &&
208 !payload->sign_data) {
209 SILC_LOG_DEBUG(("Signature data is missing"));
210 return SILC_SKE_STATUS_ERROR;
213 /* Encode the integer into binary data */
214 x_str = silc_mp_mp2bin(&payload->x, 0, &x_len);
216 /* Allocate channel payload buffer. The length of the buffer
217 is 4 + public key + 2 + x + 2 + signature. */
218 buf = silc_buffer_alloc(4 + payload->pk_len + 2 + x_len +
219 2 + payload->sign_len);
221 return SILC_SKE_STATUS_OUT_OF_MEMORY;
222 silc_buffer_pull_tail(buf, SILC_BUFFER_END(buf));
224 /* Encode the payload */
225 ret = silc_buffer_format(buf,
226 SILC_STR_UI_SHORT(payload->pk_len),
227 SILC_STR_UI_SHORT(payload->pk_type),
228 SILC_STR_UI_XNSTRING(payload->pk_data,
230 SILC_STR_UI_SHORT(x_len),
231 SILC_STR_UI_XNSTRING(x_str, x_len),
232 SILC_STR_UI_SHORT(payload->sign_len),
233 SILC_STR_UI_XNSTRING(payload->sign_data,
237 memset(x_str, 'F', x_len);
239 silc_buffer_free(buf);
240 return SILC_SKE_STATUS_ERROR;
243 /* Return encoded buffer */
244 *return_buffer = buf;
246 SILC_LOG_HEXDUMP(("KE Payload"), buf->data, buf->len);
248 memset(x_str, 'F', x_len);
251 return SILC_SKE_STATUS_OK;
254 /* Parses the Key Exchange Payload. Parsed data is returned to allocated
255 payload structure. */
257 SilcSKEStatus silc_ske_payload_ke_decode(SilcSKE ske,
259 SilcSKEKEPayload **return_payload)
261 SilcSKEStatus status = SILC_SKE_STATUS_ERROR;
262 SilcSKEKEPayload *payload;
263 unsigned char *x = NULL;
265 SilcUInt32 tot_len = 0, len2;
268 SILC_LOG_DEBUG(("Decoding Key Exchange Payload"));
270 SILC_LOG_HEXDUMP(("KE Payload"), buffer->data, buffer->len);
272 payload = silc_calloc(1, sizeof(*payload));
274 return SILC_SKE_STATUS_OUT_OF_MEMORY;
278 /* Parse start of the payload */
279 ret = silc_buffer_unformat(buffer,
280 SILC_STR_UI_SHORT(&payload->pk_len),
281 SILC_STR_UI_SHORT(&payload->pk_type),
284 SILC_LOG_ERROR(("Cannot decode public key from KE payload"));
285 status = SILC_SKE_STATUS_BAD_PAYLOAD;
289 if (ske->start_payload &&
290 ((payload->pk_type < SILC_SKE_PK_TYPE_SILC ||
291 payload->pk_type > SILC_SKE_PK_TYPE_SPKI) || !payload->pk_len)) {
292 SILC_LOG_ERROR(("Malformed public key in KE payload"));
293 status = SILC_SKE_STATUS_BAD_PAYLOAD;
297 tot_len += payload->pk_len + 4;
299 /* Parse PK data and the signature */
300 silc_buffer_pull(buffer, 4);
301 ret = silc_buffer_unformat(buffer,
302 SILC_STR_UI_XNSTRING_ALLOC(&payload->pk_data,
304 SILC_STR_UI16_NSTRING_ALLOC(&x, &x_len),
305 SILC_STR_UI16_NSTRING_ALLOC(&payload->sign_data,
309 SILC_LOG_ERROR(("Malformed KE Payload"));
310 status = SILC_SKE_STATUS_BAD_PAYLOAD;
314 tot_len += x_len + 2;
315 tot_len += payload->sign_len + 2;
318 SILC_LOG_ERROR(("Too short DH value in KE Payload"));
319 status = SILC_SKE_STATUS_BAD_PAYLOAD;
323 if (ske->start_payload &&
324 (ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL) &&
325 (payload->sign_len < 3 || !payload->sign_data)) {
326 SILC_LOG_ERROR(("The signature data is missing - both parties are "
327 "required to do authentication"));
328 status = SILC_SKE_STATUS_BAD_PAYLOAD;
332 if (tot_len != len2) {
333 SILC_LOG_ERROR(("Garbage after KE payload"));
334 status = SILC_SKE_STATUS_BAD_PAYLOAD_LENGTH;
338 /* Decode the binary data to integer */
339 silc_mp_init(&payload->x);
340 silc_mp_bin2mp(x, x_len, &payload->x);
341 memset(x, 0, sizeof(x_len));
344 /* Return the payload */
345 *return_payload = payload;
347 return SILC_SKE_STATUS_OK;
350 silc_free(payload->pk_data);
351 silc_free(payload->sign_data);
354 ske->status = status;
358 /* Free's KE Payload */
360 void silc_ske_payload_ke_free(SilcSKEKEPayload *payload)
363 silc_free(payload->pk_data);
364 silc_mp_uninit(&payload->x);
365 silc_free(payload->sign_data);