1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.] */
56 
57 #include <openssl/evp.h>
58 
59 #include <stdio.h>
60 #include <string.h>
61 
62 #include <openssl/err.h>
63 #include <openssl/mem.h>
64 #include <openssl/obj.h>
65 
66 #include "internal.h"
67 
68 
69 extern const EVP_PKEY_METHOD rsa_pkey_meth;
70 extern const EVP_PKEY_METHOD hmac_pkey_meth;
71 extern const EVP_PKEY_METHOD ec_pkey_meth;
72 
73 static const EVP_PKEY_METHOD *const evp_methods[] = {
74   &rsa_pkey_meth,
75   &hmac_pkey_meth,
76   &ec_pkey_meth,
77 };
78 
evp_pkey_meth_find(int type)79 static const EVP_PKEY_METHOD *evp_pkey_meth_find(int type) {
80   unsigned i;
81 
82   for (i = 0; i < sizeof(evp_methods)/sizeof(EVP_PKEY_METHOD*); i++) {
83     if (evp_methods[i]->pkey_id == type) {
84       return evp_methods[i];
85     }
86   }
87 
88   return NULL;
89 }
90 
evp_pkey_ctx_new(EVP_PKEY * pkey,ENGINE * e,int id)91 static EVP_PKEY_CTX *evp_pkey_ctx_new(EVP_PKEY *pkey, ENGINE *e, int id) {
92   EVP_PKEY_CTX *ret;
93   const EVP_PKEY_METHOD *pmeth;
94 
95   if (id == -1) {
96     if (!pkey || !pkey->ameth) {
97       return NULL;
98     }
99     id = pkey->ameth->pkey_id;
100   }
101 
102   pmeth = evp_pkey_meth_find(id);
103 
104   if (pmeth == NULL) {
105     OPENSSL_PUT_ERROR(EVP, evp_pkey_ctx_new, EVP_R_UNSUPPORTED_ALGORITHM);
106     const char *name = OBJ_nid2sn(id);
107     ERR_add_error_dataf("algorithm %d (%s)", id, name);
108     return NULL;
109   }
110 
111   ret = OPENSSL_malloc(sizeof(EVP_PKEY_CTX));
112   if (!ret) {
113     OPENSSL_PUT_ERROR(EVP, evp_pkey_ctx_new, ERR_R_MALLOC_FAILURE);
114     return NULL;
115   }
116   memset(ret, 0, sizeof(EVP_PKEY_CTX));
117 
118   ret->engine = e;
119   ret->pmeth = pmeth;
120   ret->operation = EVP_PKEY_OP_UNDEFINED;
121 
122   if (pkey) {
123     ret->pkey = EVP_PKEY_up_ref(pkey);
124   }
125 
126   if (pmeth->init) {
127     if (pmeth->init(ret) <= 0) {
128       EVP_PKEY_free(ret->pkey);
129       OPENSSL_free(ret);
130       return NULL;
131     }
132   }
133 
134   return ret;
135 }
136 
EVP_PKEY_CTX_new(EVP_PKEY * pkey,ENGINE * e)137 EVP_PKEY_CTX *EVP_PKEY_CTX_new(EVP_PKEY *pkey, ENGINE *e) {
138   return evp_pkey_ctx_new(pkey, e, -1);
139 }
140 
EVP_PKEY_CTX_new_id(int id,ENGINE * e)141 EVP_PKEY_CTX *EVP_PKEY_CTX_new_id(int id, ENGINE *e) {
142   return evp_pkey_ctx_new(NULL, e, id);
143 }
144 
EVP_PKEY_CTX_free(EVP_PKEY_CTX * ctx)145 void EVP_PKEY_CTX_free(EVP_PKEY_CTX *ctx) {
146   if (ctx == NULL) {
147     return;
148   }
149   if (ctx->pmeth && ctx->pmeth->cleanup) {
150     ctx->pmeth->cleanup(ctx);
151   }
152   EVP_PKEY_free(ctx->pkey);
153   EVP_PKEY_free(ctx->peerkey);
154   OPENSSL_free(ctx);
155 }
156 
EVP_PKEY_CTX_dup(EVP_PKEY_CTX * pctx)157 EVP_PKEY_CTX *EVP_PKEY_CTX_dup(EVP_PKEY_CTX *pctx) {
158   EVP_PKEY_CTX *rctx;
159 
160   if (!pctx->pmeth || !pctx->pmeth->copy) {
161     return NULL;
162   }
163 
164   rctx = OPENSSL_malloc(sizeof(EVP_PKEY_CTX));
165   if (!rctx) {
166     return NULL;
167   }
168 
169   memset(rctx, 0, sizeof(EVP_PKEY_CTX));
170 
171   rctx->pmeth = pctx->pmeth;
172   rctx->engine = pctx->engine;
173   rctx->operation = pctx->operation;
174 
175   if (pctx->pkey) {
176     rctx->pkey = EVP_PKEY_up_ref(pctx->pkey);
177     if (rctx->pkey == NULL) {
178       goto err;
179     }
180   }
181 
182   if (pctx->peerkey) {
183     rctx->peerkey = EVP_PKEY_up_ref(pctx->peerkey);
184     if (rctx->peerkey == NULL) {
185       goto err;
186     }
187   }
188 
189   if (pctx->pmeth->copy(rctx, pctx) > 0) {
190     return rctx;
191   }
192 
193 err:
194   EVP_PKEY_CTX_free(rctx);
195   OPENSSL_PUT_ERROR(EVP, EVP_PKEY_CTX_dup, ERR_LIB_EVP);
196   return NULL;
197 }
198 
EVP_PKEY_CTX_get0_pkey(EVP_PKEY_CTX * ctx)199 EVP_PKEY *EVP_PKEY_CTX_get0_pkey(EVP_PKEY_CTX *ctx) { return ctx->pkey; }
200 
EVP_PKEY_CTX_set_app_data(EVP_PKEY_CTX * ctx,void * data)201 void EVP_PKEY_CTX_set_app_data(EVP_PKEY_CTX *ctx, void *data) {
202   ctx->app_data = data;
203 }
204 
EVP_PKEY_CTX_get_app_data(EVP_PKEY_CTX * ctx)205 void *EVP_PKEY_CTX_get_app_data(EVP_PKEY_CTX *ctx) { return ctx->app_data; }
206 
EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX * ctx,int keytype,int optype,int cmd,int p1,void * p2)207 int EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX *ctx, int keytype, int optype, int cmd,
208                       int p1, void *p2) {
209   if (!ctx || !ctx->pmeth || !ctx->pmeth->ctrl) {
210     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_CTX_ctrl, EVP_R_COMMAND_NOT_SUPPORTED);
211     return 0;
212   }
213   if (keytype != -1 && ctx->pmeth->pkey_id != keytype) {
214     return 0;
215   }
216 
217   if (ctx->operation == EVP_PKEY_OP_UNDEFINED) {
218     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_CTX_ctrl, EVP_R_NO_OPERATION_SET);
219     return 0;
220   }
221 
222   if (optype != -1 && !(ctx->operation & optype)) {
223     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_CTX_ctrl, EVP_R_INVALID_OPERATION);
224     return 0;
225   }
226 
227   return ctx->pmeth->ctrl(ctx, cmd, p1, p2);
228 }
229 
EVP_PKEY_sign_init(EVP_PKEY_CTX * ctx)230 int EVP_PKEY_sign_init(EVP_PKEY_CTX *ctx) {
231   if (!ctx || !ctx->pmeth || !ctx->pmeth->sign) {
232     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_sign_init,
233                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
234     return 0;
235   }
236 
237   ctx->operation = EVP_PKEY_OP_SIGN;
238   if (!ctx->pmeth->sign_init) {
239     return 1;
240   }
241 
242   if (!ctx->pmeth->sign_init(ctx)) {
243     ctx->operation = EVP_PKEY_OP_UNDEFINED;
244     return 0;
245   }
246 
247   return 1;
248 }
249 
EVP_PKEY_sign(EVP_PKEY_CTX * ctx,uint8_t * sig,size_t * sig_len,const uint8_t * data,size_t data_len)250 int EVP_PKEY_sign(EVP_PKEY_CTX *ctx, uint8_t *sig, size_t *sig_len,
251                   const uint8_t *data, size_t data_len) {
252   if (!ctx || !ctx->pmeth || !ctx->pmeth->sign) {
253     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_sign,
254                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
255     return 0;
256   }
257   if (ctx->operation != EVP_PKEY_OP_SIGN) {
258     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_sign, EVP_R_OPERATON_NOT_INITIALIZED);
259     return 0;
260   }
261   return ctx->pmeth->sign(ctx, sig, sig_len, data, data_len);
262 }
263 
EVP_PKEY_verify_init(EVP_PKEY_CTX * ctx)264 int EVP_PKEY_verify_init(EVP_PKEY_CTX *ctx) {
265   if (!ctx || !ctx->pmeth || !ctx->pmeth->verify) {
266     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_verify_init,
267                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
268     return 0;
269   }
270   ctx->operation = EVP_PKEY_OP_VERIFY;
271   if (!ctx->pmeth->verify_init) {
272     return 1;
273   }
274   if (!ctx->pmeth->verify_init(ctx)) {
275     ctx->operation = EVP_PKEY_OP_UNDEFINED;
276     return 0;
277   }
278 
279   return 1;
280 }
281 
EVP_PKEY_verify(EVP_PKEY_CTX * ctx,const uint8_t * sig,size_t sig_len,const uint8_t * data,size_t data_len)282 int EVP_PKEY_verify(EVP_PKEY_CTX *ctx, const uint8_t *sig, size_t sig_len,
283                     const uint8_t *data, size_t data_len) {
284   if (!ctx || !ctx->pmeth || !ctx->pmeth->verify) {
285     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_verify,
286                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
287     return 0;
288   }
289   if (ctx->operation != EVP_PKEY_OP_VERIFY) {
290     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_verify, EVP_R_OPERATON_NOT_INITIALIZED);
291     return 0;
292   }
293   return ctx->pmeth->verify(ctx, sig, sig_len, data, data_len);
294 }
295 
EVP_PKEY_encrypt_init(EVP_PKEY_CTX * ctx)296 int EVP_PKEY_encrypt_init(EVP_PKEY_CTX *ctx) {
297   if (!ctx || !ctx->pmeth || !ctx->pmeth->encrypt) {
298     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_encrypt_init,
299                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
300     return 0;
301   }
302   ctx->operation = EVP_PKEY_OP_ENCRYPT;
303   if (!ctx->pmeth->encrypt_init) {
304     return 1;
305   }
306   if (!ctx->pmeth->encrypt_init(ctx)) {
307     ctx->operation = EVP_PKEY_OP_UNDEFINED;
308     return 0;
309   }
310   return 1;
311 }
312 
EVP_PKEY_encrypt(EVP_PKEY_CTX * ctx,uint8_t * out,size_t * outlen,const uint8_t * in,size_t inlen)313 int EVP_PKEY_encrypt(EVP_PKEY_CTX *ctx, uint8_t *out, size_t *outlen,
314                      const uint8_t *in, size_t inlen) {
315   if (!ctx || !ctx->pmeth || !ctx->pmeth->encrypt) {
316     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_encrypt,
317                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
318     return 0;
319   }
320   if (ctx->operation != EVP_PKEY_OP_ENCRYPT) {
321     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_encrypt, EVP_R_OPERATON_NOT_INITIALIZED);
322     return 0;
323   }
324   return ctx->pmeth->encrypt(ctx, out, outlen, in, inlen);
325 }
326 
EVP_PKEY_decrypt_init(EVP_PKEY_CTX * ctx)327 int EVP_PKEY_decrypt_init(EVP_PKEY_CTX *ctx) {
328   if (!ctx || !ctx->pmeth || !ctx->pmeth->decrypt) {
329     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_decrypt_init,
330                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
331     return 0;
332   }
333   ctx->operation = EVP_PKEY_OP_DECRYPT;
334   if (!ctx->pmeth->decrypt_init) {
335     return 1;
336   }
337   if (!ctx->pmeth->decrypt_init(ctx)) {
338     ctx->operation = EVP_PKEY_OP_UNDEFINED;
339     return 0;
340   }
341   return 1;
342 }
343 
EVP_PKEY_decrypt(EVP_PKEY_CTX * ctx,uint8_t * out,size_t * outlen,const uint8_t * in,size_t inlen)344 int EVP_PKEY_decrypt(EVP_PKEY_CTX *ctx, uint8_t *out, size_t *outlen,
345                      const uint8_t *in, size_t inlen) {
346   if (!ctx || !ctx->pmeth || !ctx->pmeth->decrypt) {
347     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_decrypt,
348                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
349     return 0;
350   }
351   if (ctx->operation != EVP_PKEY_OP_DECRYPT) {
352     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_decrypt, EVP_R_OPERATON_NOT_INITIALIZED);
353     return 0;
354   }
355   return ctx->pmeth->decrypt(ctx, out, outlen, in, inlen);
356 }
357 
EVP_PKEY_derive_init(EVP_PKEY_CTX * ctx)358 int EVP_PKEY_derive_init(EVP_PKEY_CTX *ctx) {
359   if (!ctx || !ctx->pmeth || !ctx->pmeth->derive) {
360     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_derive_init,
361                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
362     return 0;
363   }
364   ctx->operation = EVP_PKEY_OP_DERIVE;
365   if (!ctx->pmeth->derive_init) {
366     return 1;
367   }
368   if (!ctx->pmeth->derive_init(ctx)) {
369     ctx->operation = EVP_PKEY_OP_UNDEFINED;
370     return 0;
371   }
372   return 1;
373 }
374 
EVP_PKEY_derive_set_peer(EVP_PKEY_CTX * ctx,EVP_PKEY * peer)375 int EVP_PKEY_derive_set_peer(EVP_PKEY_CTX *ctx, EVP_PKEY *peer) {
376   int ret;
377   if (!ctx || !ctx->pmeth ||
378       !(ctx->pmeth->derive || ctx->pmeth->encrypt || ctx->pmeth->decrypt) ||
379       !ctx->pmeth->ctrl) {
380     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_derive_set_peer,
381                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
382     return 0;
383   }
384   if (ctx->operation != EVP_PKEY_OP_DERIVE &&
385       ctx->operation != EVP_PKEY_OP_ENCRYPT &&
386       ctx->operation != EVP_PKEY_OP_DECRYPT) {
387     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_derive_set_peer,
388                       EVP_R_OPERATON_NOT_INITIALIZED);
389     return 0;
390   }
391 
392   ret = ctx->pmeth->ctrl(ctx, EVP_PKEY_CTRL_PEER_KEY, 0, peer);
393 
394   if (ret <= 0) {
395     return 0;
396   }
397 
398   if (ret == 2) {
399     return 1;
400   }
401 
402   if (!ctx->pkey) {
403     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_derive_set_peer, EVP_R_NO_KEY_SET);
404     return 0;
405   }
406 
407   if (ctx->pkey->type != peer->type) {
408     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_derive_set_peer, EVP_R_DIFFERENT_KEY_TYPES);
409     return 0;
410   }
411 
412   /* ran@cryptocom.ru: For clarity.  The error is if parameters in peer are
413    * present (!missing) but don't match.  EVP_PKEY_cmp_parameters may return
414    * 1 (match), 0 (don't match) and -2 (comparison is not defined).  -1
415    * (different key types) is impossible here because it is checked earlier.
416    * -2 is OK for us here, as well as 1, so we can check for 0 only. */
417   if (!EVP_PKEY_missing_parameters(peer) &&
418       !EVP_PKEY_cmp_parameters(ctx->pkey, peer)) {
419     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_derive_set_peer,
420                       EVP_R_DIFFERENT_PARAMETERS);
421     return 0;
422   }
423 
424   EVP_PKEY_free(ctx->peerkey);
425   ctx->peerkey = peer;
426 
427   ret = ctx->pmeth->ctrl(ctx, EVP_PKEY_CTRL_PEER_KEY, 1, peer);
428 
429   if (ret <= 0) {
430     ctx->peerkey = NULL;
431     return 0;
432   }
433 
434   EVP_PKEY_up_ref(peer);
435   return 1;
436 }
437 
EVP_PKEY_derive(EVP_PKEY_CTX * ctx,uint8_t * key,size_t * out_key_len)438 int EVP_PKEY_derive(EVP_PKEY_CTX *ctx, uint8_t *key, size_t *out_key_len) {
439   if (!ctx || !ctx->pmeth || !ctx->pmeth->derive) {
440     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_derive,
441                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
442     return 0;
443   }
444   if (ctx->operation != EVP_PKEY_OP_DERIVE) {
445     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_derive, EVP_R_OPERATON_NOT_INITIALIZED);
446     return 0;
447   }
448   return ctx->pmeth->derive(ctx, key, out_key_len);
449 }
450 
EVP_PKEY_keygen_init(EVP_PKEY_CTX * ctx)451 int EVP_PKEY_keygen_init(EVP_PKEY_CTX *ctx) {
452   if (!ctx || !ctx->pmeth || !ctx->pmeth->keygen) {
453     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_keygen_init,
454                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
455     return 0;
456   }
457   ctx->operation = EVP_PKEY_OP_KEYGEN;
458   if (!ctx->pmeth->keygen_init) {
459     return 1;
460   }
461   if (!ctx->pmeth->keygen_init(ctx)) {
462     ctx->operation = EVP_PKEY_OP_UNDEFINED;
463     return 0;
464   }
465   return 1;
466 }
467 
EVP_PKEY_keygen(EVP_PKEY_CTX * ctx,EVP_PKEY ** ppkey)468 int EVP_PKEY_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY **ppkey) {
469   if (!ctx || !ctx->pmeth || !ctx->pmeth->keygen) {
470     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_keygen,
471                       EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
472     return 0;
473   }
474   if (ctx->operation != EVP_PKEY_OP_KEYGEN) {
475     OPENSSL_PUT_ERROR(EVP, EVP_PKEY_keygen, EVP_R_OPERATON_NOT_INITIALIZED);
476     return 0;
477   }
478 
479   if (!ppkey) {
480     return 0;
481   }
482 
483   if (!*ppkey) {
484     *ppkey = EVP_PKEY_new();
485     if (!*ppkey) {
486       OPENSSL_PUT_ERROR(EVP, EVP_PKEY_keygen, ERR_LIB_EVP);
487       return 0;
488     }
489   }
490 
491   if (!ctx->pmeth->keygen(ctx, *ppkey)) {
492     EVP_PKEY_free(*ppkey);
493     *ppkey = NULL;
494     return 0;
495   }
496   return 1;
497 }
498