5 Author: Pekka Riikonen <priikone@silcnet.org>
7 Copyright (C) 2000 - 2005 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; version 2 of the License.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
22 #include "silcske_i.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_size(payload->len);
41 return SILC_SKE_STATUS_OUT_OF_MEMORY;
43 /* Encode the payload */
44 ret = silc_buffer_format(buf,
45 SILC_STR_UI_CHAR(0), /* RESERVED field */
46 SILC_STR_UI_CHAR(payload->flags),
47 SILC_STR_UI_SHORT(payload->len),
48 SILC_STR_UI_XNSTRING(payload->cookie,
50 SILC_STR_UI_SHORT(payload->version_len),
51 SILC_STR_UI_XNSTRING(payload->version,
52 payload->version_len),
53 SILC_STR_UI_SHORT(payload->ke_grp_len),
54 SILC_STR_UI_XNSTRING(payload->ke_grp_list,
56 SILC_STR_UI_SHORT(payload->pkcs_alg_len),
57 SILC_STR_UI_XNSTRING(payload->pkcs_alg_list,
58 payload->pkcs_alg_len),
59 SILC_STR_UI_SHORT(payload->enc_alg_len),
60 SILC_STR_UI_XNSTRING(payload->enc_alg_list,
61 payload->enc_alg_len),
62 SILC_STR_UI_SHORT(payload->hash_alg_len),
63 SILC_STR_UI_XNSTRING(payload->hash_alg_list,
64 payload->hash_alg_len),
65 SILC_STR_UI_SHORT(payload->hmac_alg_len),
66 SILC_STR_UI_XNSTRING(payload->hmac_alg_list,
67 payload->hmac_alg_len),
68 SILC_STR_UI_SHORT(payload->comp_alg_len),
69 SILC_STR_UI_XNSTRING(payload->comp_alg_list,
70 payload->comp_alg_len),
73 silc_buffer_free(buf);
74 return SILC_SKE_STATUS_ERROR;
77 /* Return the encoded buffer */
80 SILC_LOG_HEXDUMP(("KE Start Payload"), buf->data, silc_buffer_len(buf));
82 return SILC_SKE_STATUS_OK;
85 /* Parses the Key Exchange Start Payload. Parsed data is returned
86 to allocated payload structure. */
89 silc_ske_payload_start_decode(SilcSKE ske,
91 SilcSKEStartPayload *return_payload)
93 SilcSKEStartPayload payload;
94 SilcSKEStatus status = SILC_SKE_STATUS_ERROR;
98 SILC_LOG_DEBUG(("Decoding Key Exchange Start Payload"));
100 SILC_LOG_HEXDUMP(("KE Start Payload"), buffer->data,
101 silc_buffer_len(buffer));
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_ERROR(("Bad RESERVED field in KE Start Payload"));
139 status = SILC_SKE_STATUS_BAD_RESERVED_FIELD;
143 if (payload->len != silc_buffer_len(buffer)) {
144 SILC_LOG_ERROR(("Garbage after KE Start Payload"));
145 status = SILC_SKE_STATUS_BAD_PAYLOAD_LENGTH;
149 /* Check for mandatory fields */
150 if (!payload->cookie || !payload->version_len ||
151 !payload->ke_grp_len || !payload->pkcs_alg_len ||
152 !payload->enc_alg_len || !payload->hash_alg_len ||
153 !payload->hmac_alg_len) {
154 SILC_LOG_ERROR(("KE Start Payload is missing mandatory fields"));
155 status = SILC_SKE_STATUS_BAD_PAYLOAD;
159 /* Return the payload */
160 *return_payload = payload;
162 return SILC_SKE_STATUS_OK;
165 silc_ske_payload_start_free(payload);
167 ske->status = status;
171 /* Free's Start Payload */
173 void silc_ske_payload_start_free(SilcSKEStartPayload payload)
176 silc_free(payload->cookie);
177 silc_free(payload->version);
178 silc_free(payload->ke_grp_list);
179 silc_free(payload->pkcs_alg_list);
180 silc_free(payload->enc_alg_list);
181 silc_free(payload->hash_alg_list);
182 silc_free(payload->hmac_alg_list);
183 silc_free(payload->comp_alg_list);
188 /* Encodes Key Exchange Payload into a SILC Buffer to be sent to the other
191 SilcSKEStatus silc_ske_payload_ke_encode(SilcSKE ske,
192 SilcSKEKEPayload payload,
193 SilcBuffer *return_buffer)
196 unsigned char *x_str;
200 SILC_LOG_DEBUG(("Encoding KE Payload"));
203 return SILC_SKE_STATUS_ERROR;
205 if (ske->start_payload &&
206 ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL &&
207 !payload->sign_data) {
208 SILC_LOG_DEBUG(("Signature data is missing"));
209 return SILC_SKE_STATUS_ERROR;
212 /* Encode the integer into binary data */
213 x_str = silc_mp_mp2bin(&payload->x, 0, &x_len);
215 /* Allocate channel payload buffer. The length of the buffer
216 is 4 + public key + 2 + x + 2 + signature. */
217 buf = silc_buffer_alloc_size(4 + payload->pk_len + 2 + x_len +
218 2 + payload->sign_len);
220 return SILC_SKE_STATUS_OUT_OF_MEMORY;
222 /* Encode the payload */
223 ret = silc_buffer_format(buf,
224 SILC_STR_UI_SHORT(payload->pk_len),
225 SILC_STR_UI_SHORT(payload->pk_type),
226 SILC_STR_UI_XNSTRING(payload->pk_data,
228 SILC_STR_UI_SHORT(x_len),
229 SILC_STR_UI_XNSTRING(x_str, x_len),
230 SILC_STR_UI_SHORT(payload->sign_len),
231 SILC_STR_UI_XNSTRING(payload->sign_data,
235 memset(x_str, 'F', x_len);
237 silc_buffer_free(buf);
238 return SILC_SKE_STATUS_ERROR;
241 /* Return encoded buffer */
242 *return_buffer = buf;
244 SILC_LOG_HEXDUMP(("KE Payload"), buf->data, silc_buffer_len(buf));
246 memset(x_str, 'F', x_len);
249 return SILC_SKE_STATUS_OK;
252 /* Parses the Key Exchange Payload. Parsed data is returned to allocated
253 payload structure. */
255 SilcSKEStatus silc_ske_payload_ke_decode(SilcSKE ske,
257 SilcSKEKEPayload *return_payload)
259 SilcSKEStatus status = SILC_SKE_STATUS_ERROR;
260 SilcSKEKEPayload payload;
261 unsigned char *x = NULL;
263 SilcUInt32 tot_len = 0, len2;
266 SILC_LOG_DEBUG(("Decoding Key Exchange Payload"));
268 SILC_LOG_HEXDUMP(("KE Payload"), buffer->data, silc_buffer_len(buffer));
270 payload = silc_calloc(1, sizeof(*payload));
272 return SILC_SKE_STATUS_OUT_OF_MEMORY;
274 len2 = silc_buffer_len(buffer);
276 /* Parse start of the payload */
277 ret = silc_buffer_unformat(buffer,
278 SILC_STR_UI_SHORT(&payload->pk_len),
279 SILC_STR_UI_SHORT(&payload->pk_type),
282 SILC_LOG_ERROR(("Cannot decode public key from KE payload"));
283 status = SILC_SKE_STATUS_BAD_PAYLOAD;
287 if (ske->start_payload &&
288 ((payload->pk_type < SILC_SKE_PK_TYPE_SILC ||
289 payload->pk_type > SILC_SKE_PK_TYPE_SPKI) || !payload->pk_len)) {
290 SILC_LOG_ERROR(("Malformed public key in KE payload"));
291 status = SILC_SKE_STATUS_BAD_PAYLOAD;
295 tot_len += payload->pk_len + 4;
297 /* Parse PK data and the signature */
298 silc_buffer_pull(buffer, 4);
299 ret = silc_buffer_unformat(buffer,
300 SILC_STR_UI_XNSTRING_ALLOC(&payload->pk_data,
302 SILC_STR_UI16_NSTRING_ALLOC(&x, &x_len),
303 SILC_STR_UI16_NSTRING_ALLOC(&payload->sign_data,
307 SILC_LOG_ERROR(("Malformed KE Payload"));
308 status = SILC_SKE_STATUS_BAD_PAYLOAD;
312 tot_len += x_len + 2;
313 tot_len += payload->sign_len + 2;
316 SILC_LOG_ERROR(("Too short DH value in KE Payload"));
317 status = SILC_SKE_STATUS_BAD_PAYLOAD;
321 if (ske->start_payload &&
322 (ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL) &&
323 (payload->sign_len < 3 || !payload->sign_data)) {
324 SILC_LOG_ERROR(("The signature data is missing - both parties are "
325 "required to do authentication"));
326 status = SILC_SKE_STATUS_BAD_PAYLOAD;
330 if (tot_len != len2) {
331 SILC_LOG_ERROR(("Garbage after KE payload"));
332 status = SILC_SKE_STATUS_BAD_PAYLOAD_LENGTH;
336 /* Decode the binary data to integer */
337 silc_mp_init(&payload->x);
338 silc_mp_bin2mp(x, x_len, &payload->x);
339 memset(x, 0, sizeof(x_len));
342 /* Return the payload */
343 *return_payload = payload;
345 return SILC_SKE_STATUS_OK;
348 silc_free(payload->pk_data);
349 silc_free(payload->sign_data);
352 ske->status = status;
356 /* Free's KE Payload */
358 void silc_ske_payload_ke_free(SilcSKEKEPayload payload)
361 silc_free(payload->pk_data);
362 silc_mp_uninit(&payload->x);
363 silc_free(payload->sign_data);