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1 /*
2  * Key Derivation that doesn't use PKCS11
3  *
4  * This Source Code Form is subject to the terms of the Mozilla Public
5  * License, v. 2.0. If a copy of the MPL was not distributed with this
6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
7 
8 #include "ssl.h" 	/* prereq to sslimpl.h */
9 #include "certt.h"	/* prereq to sslimpl.h */
10 #include "keythi.h"	/* prereq to sslimpl.h */
11 #include "sslimpl.h"
12 #ifndef NO_PKCS11_BYPASS
13 #include "blapi.h"
14 #endif
15 
16 #include "keyhi.h"
17 #include "pk11func.h"
18 #include "secasn1.h"
19 #include "cert.h"
20 #include "secmodt.h"
21 
22 #include "sslproto.h"
23 #include "sslerr.h"
24 
25 #ifndef NO_PKCS11_BYPASS
26 /* make this a macro! */
27 #ifdef NOT_A_MACRO
28 static void
buildSSLKey(unsigned char * keyBlock,unsigned int keyLen,SECItem * result,const char * label)29 buildSSLKey(unsigned char * keyBlock, unsigned int keyLen, SECItem * result,
30             const char * label)
31 {
32     result->type = siBuffer;
33     result->data = keyBlock;
34     result->len  = keyLen;
35     PRINT_BUF(100, (NULL, label, keyBlock, keyLen));
36 }
37 #else
38 #define buildSSLKey(keyBlock, keyLen, result, label) \
39 { \
40     (result)->type = siBuffer; \
41     (result)->data = keyBlock; \
42     (result)->len  = keyLen; \
43     PRINT_BUF(100, (NULL, label, keyBlock, keyLen)); \
44 }
45 #endif
46 
47 /*
48  * SSL Key generation given pre master secret
49  */
50 #ifndef NUM_MIXERS
51 #define NUM_MIXERS 9
52 #endif
53 static const char * const mixers[NUM_MIXERS] = {
54     "A",
55     "BB",
56     "CCC",
57     "DDDD",
58     "EEEEE",
59     "FFFFFF",
60     "GGGGGGG",
61     "HHHHHHHH",
62     "IIIIIIIII"
63 };
64 
65 
66 SECStatus
ssl3_KeyAndMacDeriveBypass(ssl3CipherSpec * pwSpec,const unsigned char * cr,const unsigned char * sr,PRBool isTLS,PRBool isExport)67 ssl3_KeyAndMacDeriveBypass(
68     ssl3CipherSpec *      pwSpec,
69     const unsigned char * cr,
70     const unsigned char * sr,
71     PRBool                isTLS,
72     PRBool                isExport)
73 {
74     const ssl3BulkCipherDef *cipher_def = pwSpec->cipher_def;
75     unsigned char * key_block    = pwSpec->key_block;
76     unsigned char * key_block2   = NULL;
77     unsigned int    block_bytes  = 0;
78     unsigned int    block_needed = 0;
79     unsigned int    i;
80     unsigned int    keySize;            /* actual    size of cipher keys */
81     unsigned int    effKeySize;		/* effective size of cipher keys */
82     unsigned int    macSize;		/* size of MAC secret */
83     unsigned int    IVSize;		/* size of IV */
84     PRBool          explicitIV = PR_FALSE;
85     SECStatus       rv    = SECFailure;
86     SECStatus       status = SECSuccess;
87     PRBool          isFIPS = PR_FALSE;
88     PRBool          isTLS12 = pwSpec->version >= SSL_LIBRARY_VERSION_TLS_1_2;
89 
90     SECItem         srcr;
91     SECItem         crsr;
92 
93     unsigned char     srcrdata[SSL3_RANDOM_LENGTH * 2];
94     unsigned char     crsrdata[SSL3_RANDOM_LENGTH * 2];
95     PRUint64          md5buf[22];
96     PRUint64          shabuf[40];
97 
98 #define md5Ctx ((MD5Context *)md5buf)
99 #define shaCtx ((SHA1Context *)shabuf)
100 
101     static const SECItem zed  = { siBuffer, NULL, 0 };
102 
103     if (pwSpec->msItem.data == NULL ||
104         pwSpec->msItem.len  != SSL3_MASTER_SECRET_LENGTH) {
105 	PORT_SetError(SEC_ERROR_INVALID_ARGS);
106 	return rv;
107     }
108 
109     PRINT_BUF(100, (NULL, "Master Secret", pwSpec->msItem.data,
110                                            pwSpec->msItem.len));
111 
112     /* figure out how much is needed */
113     macSize    = pwSpec->mac_size;
114     keySize    = cipher_def->key_size;
115     effKeySize = cipher_def->secret_key_size;
116     IVSize     = cipher_def->iv_size;
117     if (keySize == 0) {
118 	effKeySize = IVSize = 0; /* only MACing */
119     }
120     if (cipher_def->type == type_block &&
121 	pwSpec->version >= SSL_LIBRARY_VERSION_TLS_1_1) {
122 	/* Block ciphers in >= TLS 1.1 use a per-record, explicit IV. */
123 	explicitIV = PR_TRUE;
124     }
125     block_needed =
126 	2 * (macSize + effKeySize + ((!isExport && !explicitIV) * IVSize));
127 
128     /*
129      * clear out our returned keys so we can recover on failure
130      */
131     pwSpec->client.write_key_item     = zed;
132     pwSpec->client.write_mac_key_item = zed;
133     pwSpec->server.write_key_item     = zed;
134     pwSpec->server.write_mac_key_item = zed;
135 
136     /* initialize the server random, client random block */
137     srcr.type   = siBuffer;
138     srcr.data   = srcrdata;
139     srcr.len    = sizeof srcrdata;
140     PORT_Memcpy(srcrdata, sr, SSL3_RANDOM_LENGTH);
141     PORT_Memcpy(srcrdata + SSL3_RANDOM_LENGTH, cr, SSL3_RANDOM_LENGTH);
142 
143     /* initialize the client random, server random block */
144     crsr.type   = siBuffer;
145     crsr.data   = crsrdata;
146     crsr.len    = sizeof crsrdata;
147     PORT_Memcpy(crsrdata, cr, SSL3_RANDOM_LENGTH);
148     PORT_Memcpy(crsrdata + SSL3_RANDOM_LENGTH, sr, SSL3_RANDOM_LENGTH);
149     PRINT_BUF(100, (NULL, "Key & MAC CRSR", crsr.data, crsr.len));
150 
151     /*
152      * generate the key material:
153      */
154     if (isTLS) {
155 	SECItem       keyblk;
156 
157 	keyblk.type = siBuffer;
158 	keyblk.data = key_block;
159 	keyblk.len  = block_needed;
160 
161 	if (isTLS12) {
162 	    status = TLS_P_hash(HASH_AlgSHA256, &pwSpec->msItem,
163 				"key expansion", &srcr, &keyblk, isFIPS);
164 	} else {
165 	    status = TLS_PRF(&pwSpec->msItem, "key expansion", &srcr, &keyblk,
166 			     isFIPS);
167 	}
168 	if (status != SECSuccess) {
169 	    goto key_and_mac_derive_fail;
170 	}
171 	block_bytes = keyblk.len;
172     } else {
173 	/* key_block =
174 	 *     MD5(master_secret + SHA('A' + master_secret +
175 	 *                      ServerHello.random + ClientHello.random)) +
176 	 *     MD5(master_secret + SHA('BB' + master_secret +
177 	 *                      ServerHello.random + ClientHello.random)) +
178 	 *     MD5(master_secret + SHA('CCC' + master_secret +
179 	 *                      ServerHello.random + ClientHello.random)) +
180 	 *     [...];
181 	 */
182 	unsigned int made = 0;
183 	for (i = 0; made < block_needed && i < NUM_MIXERS; ++i) {
184 	    unsigned int    outLen;
185 	    unsigned char   sha_out[SHA1_LENGTH];
186 
187 	    SHA1_Begin(shaCtx);
188 	    SHA1_Update(shaCtx, (unsigned char*)(mixers[i]), i+1);
189 	    SHA1_Update(shaCtx, pwSpec->msItem.data, pwSpec->msItem.len);
190 	    SHA1_Update(shaCtx, srcr.data, srcr.len);
191 	    SHA1_End(shaCtx, sha_out, &outLen, SHA1_LENGTH);
192 	    PORT_Assert(outLen == SHA1_LENGTH);
193 
194 	    MD5_Begin(md5Ctx);
195 	    MD5_Update(md5Ctx, pwSpec->msItem.data, pwSpec->msItem.len);
196 	    MD5_Update(md5Ctx, sha_out, outLen);
197 	    MD5_End(md5Ctx, key_block + made, &outLen, MD5_LENGTH);
198 	    PORT_Assert(outLen == MD5_LENGTH);
199 	    made += MD5_LENGTH;
200 	}
201 	block_bytes = made;
202     }
203     PORT_Assert(block_bytes >= block_needed);
204     PORT_Assert(block_bytes <= sizeof pwSpec->key_block);
205     PRINT_BUF(100, (NULL, "key block", key_block, block_bytes));
206 
207     /*
208      * Put the key material where it goes.
209      */
210     key_block2 = key_block + block_bytes;
211     i = 0;			/* now shows how much consumed */
212 
213     /*
214      * The key_block is partitioned as follows:
215      * client_write_MAC_secret[CipherSpec.hash_size]
216      */
217     buildSSLKey(&key_block[i],macSize, &pwSpec->client.write_mac_key_item, \
218                 "Client Write MAC Secret");
219     i += macSize;
220 
221     /*
222      * server_write_MAC_secret[CipherSpec.hash_size]
223      */
224     buildSSLKey(&key_block[i],macSize, &pwSpec->server.write_mac_key_item, \
225                 "Server Write MAC Secret");
226     i += macSize;
227 
228     if (!keySize) {
229 	/* only MACing */
230 	buildSSLKey(NULL, 0, &pwSpec->client.write_key_item, \
231 	            "Client Write Key (MAC only)");
232 	buildSSLKey(NULL, 0, &pwSpec->server.write_key_item, \
233 	            "Server Write Key (MAC only)");
234 	buildSSLKey(NULL, 0, &pwSpec->client.write_iv_item, \
235 	            "Client Write IV (MAC only)");
236 	buildSSLKey(NULL, 0, &pwSpec->server.write_iv_item, \
237 	            "Server Write IV (MAC only)");
238     } else if (!isExport) {
239 	/*
240 	** Generate Domestic write keys and IVs.
241 	** client_write_key[CipherSpec.key_material]
242 	*/
243 	buildSSLKey(&key_block[i], keySize, &pwSpec->client.write_key_item, \
244 	            "Domestic Client Write Key");
245 	i += keySize;
246 
247 	/*
248 	** server_write_key[CipherSpec.key_material]
249 	*/
250 	buildSSLKey(&key_block[i], keySize, &pwSpec->server.write_key_item, \
251 	            "Domestic Server Write Key");
252 	i += keySize;
253 
254 	if (IVSize > 0) {
255 	    if (explicitIV) {
256 		static unsigned char zero_block[32];
257 		PORT_Assert(IVSize <= sizeof zero_block);
258 		buildSSLKey(&zero_block[0], IVSize, \
259 			    &pwSpec->client.write_iv_item, \
260 			    "Domestic Client Write IV");
261 		buildSSLKey(&zero_block[0], IVSize, \
262 			    &pwSpec->server.write_iv_item, \
263 			    "Domestic Server Write IV");
264 	    } else {
265 		/*
266 		** client_write_IV[CipherSpec.IV_size]
267 		*/
268 		buildSSLKey(&key_block[i], IVSize, \
269 			    &pwSpec->client.write_iv_item, \
270 			    "Domestic Client Write IV");
271 		i += IVSize;
272 
273 		/*
274 		** server_write_IV[CipherSpec.IV_size]
275 		*/
276 		buildSSLKey(&key_block[i], IVSize, \
277 			    &pwSpec->server.write_iv_item, \
278 			    "Domestic Server Write IV");
279 		i += IVSize;
280 	    }
281 	}
282 	PORT_Assert(i <= block_bytes);
283     } else if (!isTLS) {
284 	/*
285 	** Generate SSL3 Export write keys and IVs.
286 	*/
287 	unsigned int    outLen;
288 
289 	/*
290 	** client_write_key[CipherSpec.key_material]
291 	** final_client_write_key = MD5(client_write_key +
292 	**                   ClientHello.random + ServerHello.random);
293 	*/
294 	MD5_Begin(md5Ctx);
295 	MD5_Update(md5Ctx, &key_block[i], effKeySize);
296 	MD5_Update(md5Ctx, crsr.data, crsr.len);
297 	MD5_End(md5Ctx, key_block2, &outLen, MD5_LENGTH);
298 	i += effKeySize;
299 	buildSSLKey(key_block2, keySize, &pwSpec->client.write_key_item, \
300 	            "SSL3 Export Client Write Key");
301 	key_block2 += keySize;
302 
303 	/*
304 	** server_write_key[CipherSpec.key_material]
305 	** final_server_write_key = MD5(server_write_key +
306 	**                    ServerHello.random + ClientHello.random);
307 	*/
308 	MD5_Begin(md5Ctx);
309 	MD5_Update(md5Ctx, &key_block[i], effKeySize);
310 	MD5_Update(md5Ctx, srcr.data, srcr.len);
311 	MD5_End(md5Ctx, key_block2, &outLen, MD5_LENGTH);
312 	i += effKeySize;
313 	buildSSLKey(key_block2, keySize, &pwSpec->server.write_key_item, \
314 	            "SSL3 Export Server Write Key");
315 	key_block2 += keySize;
316 	PORT_Assert(i <= block_bytes);
317 
318 	if (IVSize) {
319 	    /*
320 	    ** client_write_IV =
321 	    **	MD5(ClientHello.random + ServerHello.random);
322 	    */
323 	    MD5_Begin(md5Ctx);
324 	    MD5_Update(md5Ctx, crsr.data, crsr.len);
325 	    MD5_End(md5Ctx, key_block2, &outLen, MD5_LENGTH);
326 	    buildSSLKey(key_block2, IVSize, &pwSpec->client.write_iv_item, \
327 	                "SSL3 Export Client Write IV");
328 	    key_block2 += IVSize;
329 
330 	    /*
331 	    ** server_write_IV =
332 	    **	MD5(ServerHello.random + ClientHello.random);
333 	    */
334 	    MD5_Begin(md5Ctx);
335 	    MD5_Update(md5Ctx, srcr.data, srcr.len);
336 	    MD5_End(md5Ctx, key_block2, &outLen, MD5_LENGTH);
337 	    buildSSLKey(key_block2, IVSize, &pwSpec->server.write_iv_item, \
338 	                "SSL3 Export Server Write IV");
339 	    key_block2 += IVSize;
340 	}
341 
342 	PORT_Assert(key_block2 - key_block <= sizeof pwSpec->key_block);
343     } else {
344 	/*
345 	** Generate TLS Export write keys and IVs.
346 	*/
347 	SECItem       secret ;
348 	SECItem       keyblk ;
349 
350 	secret.type = siBuffer;
351 	keyblk.type = siBuffer;
352 	/*
353 	** client_write_key[CipherSpec.key_material]
354 	** final_client_write_key = PRF(client_write_key,
355 	**                              "client write key",
356 	**                              client_random + server_random);
357 	*/
358 	secret.data = &key_block[i];
359 	secret.len  = effKeySize;
360 	i          += effKeySize;
361 	keyblk.data = key_block2;
362 	keyblk.len  = keySize;
363 	status = TLS_PRF(&secret, "client write key", &crsr, &keyblk, isFIPS);
364 	if (status != SECSuccess) {
365 	    goto key_and_mac_derive_fail;
366 	}
367 	buildSSLKey(key_block2, keySize, &pwSpec->client.write_key_item, \
368 	            "TLS Export Client Write Key");
369 	key_block2 += keySize;
370 
371 	/*
372 	** server_write_key[CipherSpec.key_material]
373 	** final_server_write_key = PRF(server_write_key,
374 	**                              "server write key",
375 	**                              client_random + server_random);
376 	*/
377 	secret.data = &key_block[i];
378 	secret.len  = effKeySize;
379 	i          += effKeySize;
380 	keyblk.data = key_block2;
381 	keyblk.len  = keySize;
382 	status = TLS_PRF(&secret, "server write key", &crsr, &keyblk, isFIPS);
383 	if (status != SECSuccess) {
384 	    goto key_and_mac_derive_fail;
385 	}
386 	buildSSLKey(key_block2, keySize, &pwSpec->server.write_key_item, \
387 	            "TLS Export Server Write Key");
388 	key_block2 += keySize;
389 
390 	/*
391 	** iv_block = PRF("", "IV block", client_random + server_random);
392 	** client_write_IV[SecurityParameters.IV_size]
393 	** server_write_IV[SecurityParameters.IV_size]
394 	*/
395 	if (IVSize) {
396 	    secret.data = NULL;
397 	    secret.len  = 0;
398 	    keyblk.data = key_block2;
399 	    keyblk.len  = 2 * IVSize;
400 	    status = TLS_PRF(&secret, "IV block", &crsr, &keyblk, isFIPS);
401 	    if (status != SECSuccess) {
402 		goto key_and_mac_derive_fail;
403 	    }
404 	    buildSSLKey(key_block2,          IVSize, \
405 	                &pwSpec->client.write_iv_item, \
406 			"TLS Export Client Write IV");
407 	    buildSSLKey(key_block2 + IVSize, IVSize, \
408 	                &pwSpec->server.write_iv_item, \
409 			"TLS Export Server Write IV");
410 	    key_block2 += 2 * IVSize;
411 	}
412 	PORT_Assert(key_block2 - key_block <= sizeof pwSpec->key_block);
413     }
414     rv = SECSuccess;
415 
416 key_and_mac_derive_fail:
417 
418     MD5_DestroyContext(md5Ctx, PR_FALSE);
419     SHA1_DestroyContext(shaCtx, PR_FALSE);
420 
421     if (rv != SECSuccess) {
422 	PORT_SetError(SSL_ERROR_SESSION_KEY_GEN_FAILURE);
423     }
424 
425     return rv;
426 }
427 
428 
429 /* derive the Master Secret from the PMS */
430 /* Presently, this is only done wtih RSA PMS, and only on the server side,
431  * so isRSA is always true.
432  */
433 SECStatus
ssl3_MasterKeyDeriveBypass(ssl3CipherSpec * pwSpec,const unsigned char * cr,const unsigned char * sr,const SECItem * pms,PRBool isTLS,PRBool isRSA)434 ssl3_MasterKeyDeriveBypass(
435     ssl3CipherSpec *      pwSpec,
436     const unsigned char * cr,
437     const unsigned char * sr,
438     const SECItem *       pms,
439     PRBool                isTLS,
440     PRBool                isRSA)
441 {
442     unsigned char * key_block    = pwSpec->key_block;
443     SECStatus       rv    = SECSuccess;
444     PRBool          isFIPS = PR_FALSE;
445     PRBool          isTLS12 = pwSpec->version >= SSL_LIBRARY_VERSION_TLS_1_2;
446 
447     SECItem         crsr;
448 
449     unsigned char     crsrdata[SSL3_RANDOM_LENGTH * 2];
450     PRUint64          md5buf[22];
451     PRUint64          shabuf[40];
452 
453 #define md5Ctx ((MD5Context *)md5buf)
454 #define shaCtx ((SHA1Context *)shabuf)
455 
456     /* first do the consistancy checks */
457     if (isRSA) {
458 	PORT_Assert(pms->len == SSL3_RSA_PMS_LENGTH);
459 	if (pms->len != SSL3_RSA_PMS_LENGTH) {
460 	    PORT_SetError(SEC_ERROR_INVALID_ARGS);
461 	    return SECFailure;
462 	}
463 	/* caller must test PMS version for rollback */
464     }
465 
466     /* initialize the client random, server random block */
467     crsr.type   = siBuffer;
468     crsr.data   = crsrdata;
469     crsr.len    = sizeof crsrdata;
470     PORT_Memcpy(crsrdata, cr, SSL3_RANDOM_LENGTH);
471     PORT_Memcpy(crsrdata + SSL3_RANDOM_LENGTH, sr, SSL3_RANDOM_LENGTH);
472     PRINT_BUF(100, (NULL, "Master Secret CRSR", crsr.data, crsr.len));
473 
474     /* finally do the key gen */
475     if (isTLS) {
476 	SECItem master = { siBuffer, NULL, 0 };
477 
478 	master.data = key_block;
479 	master.len = SSL3_MASTER_SECRET_LENGTH;
480 
481 	if (isTLS12) {
482 	    rv = TLS_P_hash(HASH_AlgSHA256, pms, "master secret", &crsr,
483 			    &master, isFIPS);
484 	} else {
485 	    rv = TLS_PRF(pms, "master secret", &crsr, &master, isFIPS);
486 	}
487 	if (rv != SECSuccess) {
488 	    PORT_SetError(SSL_ERROR_SESSION_KEY_GEN_FAILURE);
489 	}
490     } else {
491 	int i;
492 	unsigned int made = 0;
493 	for (i = 0; i < 3; i++) {
494 	    unsigned int    outLen;
495 	    unsigned char   sha_out[SHA1_LENGTH];
496 
497 	    SHA1_Begin(shaCtx);
498 	    SHA1_Update(shaCtx, (unsigned char*) mixers[i], i+1);
499 	    SHA1_Update(shaCtx, pms->data, pms->len);
500 	    SHA1_Update(shaCtx, crsr.data, crsr.len);
501 	    SHA1_End(shaCtx, sha_out, &outLen, SHA1_LENGTH);
502 	    PORT_Assert(outLen == SHA1_LENGTH);
503 
504 	    MD5_Begin(md5Ctx);
505 	    MD5_Update(md5Ctx, pms->data, pms->len);
506 	    MD5_Update(md5Ctx, sha_out, outLen);
507 	    MD5_End(md5Ctx, key_block + made, &outLen, MD5_LENGTH);
508 	    PORT_Assert(outLen == MD5_LENGTH);
509 	    made += outLen;
510 	}
511     }
512 
513     /* store the results */
514     PORT_Memcpy(pwSpec->raw_master_secret, key_block,
515 		SSL3_MASTER_SECRET_LENGTH);
516     pwSpec->msItem.data = pwSpec->raw_master_secret;
517     pwSpec->msItem.len  = SSL3_MASTER_SECRET_LENGTH;
518     PRINT_BUF(100, (NULL, "Master Secret", pwSpec->msItem.data,
519                                            pwSpec->msItem.len));
520 
521     return rv;
522 }
523 
524 static SECStatus
ssl_canExtractMS(PK11SymKey * pms,PRBool isTLS,PRBool isDH,PRBool * pcbp)525 ssl_canExtractMS(PK11SymKey *pms, PRBool isTLS, PRBool isDH, PRBool *pcbp)
526 {   SECStatus	      rv;
527     PK11SymKey *    ms = NULL;
528     SECItem         params = {siBuffer, NULL, 0};
529     CK_SSL3_MASTER_KEY_DERIVE_PARAMS master_params;
530     unsigned char   rand[SSL3_RANDOM_LENGTH];
531     CK_VERSION      pms_version;
532     CK_MECHANISM_TYPE master_derive;
533     CK_MECHANISM_TYPE key_derive;
534     CK_FLAGS          keyFlags;
535 
536     if (pms == NULL)
537 	return(SECFailure);
538 
539     PORT_Memset(rand, 0, SSL3_RANDOM_LENGTH);
540 
541     if (isTLS) {
542 	if(isDH) master_derive = CKM_TLS_MASTER_KEY_DERIVE_DH;
543 	else master_derive = CKM_TLS_MASTER_KEY_DERIVE;
544 	key_derive    = CKM_TLS_KEY_AND_MAC_DERIVE;
545 	keyFlags      = CKF_SIGN | CKF_VERIFY;
546     } else {
547 	if (isDH) master_derive = CKM_SSL3_MASTER_KEY_DERIVE_DH;
548 	else master_derive = CKM_SSL3_MASTER_KEY_DERIVE;
549 	key_derive    = CKM_SSL3_KEY_AND_MAC_DERIVE;
550 	keyFlags      = 0;
551     }
552 
553     master_params.pVersion                     = &pms_version;
554     master_params.RandomInfo.pClientRandom     = rand;
555     master_params.RandomInfo.ulClientRandomLen = SSL3_RANDOM_LENGTH;
556     master_params.RandomInfo.pServerRandom     = rand;
557     master_params.RandomInfo.ulServerRandomLen = SSL3_RANDOM_LENGTH;
558 
559     params.data = (unsigned char *) &master_params;
560     params.len  = sizeof master_params;
561 
562     ms = PK11_DeriveWithFlags(pms, master_derive, &params, key_derive,
563 			      CKA_DERIVE, 0, keyFlags);
564     if (ms == NULL)
565 	return(SECFailure);
566 
567     rv = PK11_ExtractKeyValue(ms);
568     *pcbp = (rv == SECSuccess);
569     PK11_FreeSymKey(ms);
570 
571     return(rv);
572 
573 }
574 #endif  /* !NO_PKCS11_BYPASS */
575 
576 /* Check the key exchange algorithm for each cipher in the list to see if
577  * a master secret key can be extracted. If the KEA will use keys from the
578  * specified cert make sure the extract operation is attempted from the slot
579  * where the private key resides.
580  * If MS can be extracted for all ciphers, (*pcanbypass) is set to TRUE and
581  * SECSuccess is returned. In all other cases but one (*pcanbypass) is
582  * set to FALSE and SECFailure is returned.
583  * In that last case Derive() has been called successfully but the MS is null,
584  * CanBypass sets (*pcanbypass) to FALSE and returns SECSuccess indicating the
585  * arguments were all valid but the slot cannot be bypassed.
586  */
587 
588 /* XXX Add SSL_CBP_TLS1_1 and test it in protocolmask when setting isTLS. */
589 
590 SECStatus
SSL_CanBypass(CERTCertificate * cert,SECKEYPrivateKey * srvPrivkey,PRUint32 protocolmask,PRUint16 * ciphersuites,int nsuites,PRBool * pcanbypass,void * pwArg)591 SSL_CanBypass(CERTCertificate *cert, SECKEYPrivateKey *srvPrivkey,
592 	      PRUint32 protocolmask, PRUint16 *ciphersuites, int nsuites,
593               PRBool *pcanbypass, void *pwArg)
594 {
595 #ifdef NO_PKCS11_BYPASS
596     if (!pcanbypass) {
597         PORT_SetError(SEC_ERROR_INVALID_ARGS);
598         return SECFailure;
599     }
600     *pcanbypass = PR_FALSE;
601     return SECSuccess;
602 #else
603     SECStatus	      rv;
604     int		      i;
605     PRUint16	      suite;
606     PK11SymKey *      pms = NULL;
607     SECKEYPublicKey * srvPubkey = NULL;
608     KeyType	      privKeytype;
609     PK11SlotInfo *    slot = NULL;
610     SECItem           param;
611     CK_VERSION 	      version;
612     CK_MECHANISM_TYPE mechanism_array[2];
613     SECItem           enc_pms = {siBuffer, NULL, 0};
614     PRBool	      isTLS = PR_FALSE;
615     SSLCipherSuiteInfo csdef;
616     PRBool	      testrsa = PR_FALSE;
617     PRBool	      testrsa_export = PR_FALSE;
618     PRBool	      testecdh = PR_FALSE;
619     PRBool	      testecdhe = PR_FALSE;
620 #ifdef NSS_ENABLE_ECC
621     SECKEYECParams ecParams = { siBuffer, NULL, 0 };
622 #endif
623 
624     if (!cert || !srvPrivkey || !ciphersuites || !pcanbypass) {
625 	PORT_SetError(SEC_ERROR_INVALID_ARGS);
626         return SECFailure;
627     }
628 
629     srvPubkey = CERT_ExtractPublicKey(cert);
630     if (!srvPubkey)
631         return SECFailure;
632 
633     *pcanbypass = PR_TRUE;
634     rv = SECFailure;
635 
636     /* determine which KEAs to test */
637     /* 0 (SSL_NULL_WITH_NULL_NULL) is used as a list terminator because
638      * SSL3 and TLS specs forbid negotiating that cipher suite number.
639      */
640     for (i=0; i < nsuites && (suite = *ciphersuites++) != 0; i++) {
641 	/* skip SSL2 cipher suites and ones NSS doesn't support */
642 	if (SSL_GetCipherSuiteInfo(suite, &csdef, sizeof(csdef)) != SECSuccess
643 	    || SSL_IS_SSL2_CIPHER(suite) )
644 	    continue;
645 	switch (csdef.keaType) {
646 	case ssl_kea_rsa:
647 	    switch (csdef.cipherSuite) {
648 	    case TLS_RSA_EXPORT1024_WITH_RC4_56_SHA:
649 	    case TLS_RSA_EXPORT1024_WITH_DES_CBC_SHA:
650 	    case SSL_RSA_EXPORT_WITH_RC4_40_MD5:
651 	    case SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5:
652 		testrsa_export = PR_TRUE;
653 	    }
654 	    if (!testrsa_export)
655 		testrsa = PR_TRUE;
656 	    break;
657 	case ssl_kea_ecdh:
658 	    if (strcmp(csdef.keaTypeName, "ECDHE") == 0) /* ephemeral? */
659 		testecdhe = PR_TRUE;
660 	    else
661 		testecdh = PR_TRUE;
662 	    break;
663 	case ssl_kea_dh:
664 	    /* this is actually DHE */
665 	default:
666 	    continue;
667 	}
668     }
669 
670     /* For each protocol try to derive and extract an MS.
671      * Failure of function any function except MS extract means
672      * continue with the next cipher test. Stop testing when the list is
673      * exhausted or when the first MS extract--not derive--fails.
674      */
675     privKeytype = SECKEY_GetPrivateKeyType(srvPrivkey);
676     protocolmask &= SSL_CBP_SSL3|SSL_CBP_TLS1_0;
677     while (protocolmask) {
678 	if (protocolmask & SSL_CBP_SSL3) {
679 	    isTLS = PR_FALSE;
680 	    protocolmask ^= SSL_CBP_SSL3;
681 	} else {
682 	    isTLS = PR_TRUE;
683 	    protocolmask ^= SSL_CBP_TLS1_0;
684 	}
685 
686 	if (privKeytype == rsaKey && testrsa_export) {
687 	    if (PK11_GetPrivateModulusLen(srvPrivkey) > EXPORT_RSA_KEY_LENGTH) {
688 		*pcanbypass = PR_FALSE;
689 		rv = SECSuccess;
690 		break;
691 	    } else
692 		testrsa = PR_TRUE;
693 	}
694 	for (; privKeytype == rsaKey && testrsa; ) {
695 	    /* TLS_RSA */
696 	    unsigned char     rsaPmsBuf[SSL3_RSA_PMS_LENGTH];
697 	    unsigned int      outLen = 0;
698 	    CK_MECHANISM_TYPE target;
699 	    SECStatus	      irv;
700 
701 	    mechanism_array[0] = CKM_SSL3_PRE_MASTER_KEY_GEN;
702 	    mechanism_array[1] = CKM_RSA_PKCS;
703 
704 	    slot = PK11_GetBestSlotMultiple(mechanism_array, 2, pwArg);
705 	    if (slot == NULL) {
706 		PORT_SetError(SSL_ERROR_TOKEN_SLOT_NOT_FOUND);
707 		break;
708 	    }
709 
710 	    /* Generate the pre-master secret ...  (client side) */
711 	    version.major = 3 /*MSB(clientHelloVersion)*/;
712 	    version.minor = 0 /*LSB(clientHelloVersion)*/;
713 	    param.data = (unsigned char *)&version;
714 	    param.len  = sizeof version;
715 	    pms = PK11_KeyGen(slot, CKM_SSL3_PRE_MASTER_KEY_GEN, &param, 0, pwArg);
716 	    PK11_FreeSlot(slot);
717 	    if (!pms)
718 		break;
719 	    /* now wrap it */
720 	    enc_pms.len  = SECKEY_PublicKeyStrength(srvPubkey);
721 	    enc_pms.data = (unsigned char*)PORT_Alloc(enc_pms.len);
722 	    if (enc_pms.data == NULL) {
723 	        PORT_SetError(PR_OUT_OF_MEMORY_ERROR);
724 	        break;
725 	    }
726 	    irv = PK11_PubWrapSymKey(CKM_RSA_PKCS, srvPubkey, pms, &enc_pms);
727 	    if (irv != SECSuccess)
728 		break;
729 	    PK11_FreeSymKey(pms);
730 	    pms = NULL;
731 	    /* now do the server side--check the triple bypass first */
732 	    rv = PK11_PrivDecryptPKCS1(srvPrivkey, rsaPmsBuf, &outLen,
733 				       sizeof rsaPmsBuf,
734 				       (unsigned char *)enc_pms.data,
735 				       enc_pms.len);
736 	    /* if decrypt worked we're done with the RSA test */
737 	    if (rv == SECSuccess) {
738 		*pcanbypass = PR_TRUE;
739 		break;
740 	    }
741 	    /* check for fallback to double bypass */
742 	    target = isTLS ? CKM_TLS_MASTER_KEY_DERIVE
743 			: CKM_SSL3_MASTER_KEY_DERIVE;
744 	    pms = PK11_PubUnwrapSymKey(srvPrivkey, &enc_pms,
745 				       target, CKA_DERIVE, 0);
746 	    rv = ssl_canExtractMS(pms, isTLS, PR_FALSE, pcanbypass);
747 	    if (rv == SECSuccess && *pcanbypass == PR_FALSE)
748 		goto done;
749 	    break;
750 	}
751 
752 	/* Check for NULL to avoid double free.
753 	 * SECItem_FreeItem sets data NULL in secitem.c#265
754 	 */
755 	if (enc_pms.data != NULL) {
756 	    SECITEM_FreeItem(&enc_pms, PR_FALSE);
757         }
758 #ifdef NSS_ENABLE_ECC
759 	for (; (privKeytype == ecKey && ( testecdh || testecdhe)) ||
760 	       (privKeytype == rsaKey && testecdhe); ) {
761 	    CK_MECHANISM_TYPE target;
762 	    SECKEYPublicKey  *keapub = NULL;
763 	    SECKEYPrivateKey *keapriv;
764 	    SECKEYPublicKey  *cpub = NULL; /* client's ephemeral ECDH keys */
765 	    SECKEYPrivateKey *cpriv = NULL;
766 	    SECKEYECParams   *pecParams = NULL;
767 
768 	    if (privKeytype == ecKey && testecdhe) {
769 		/* TLS_ECDHE_ECDSA */
770 		pecParams = &srvPubkey->u.ec.DEREncodedParams;
771 	    } else if (privKeytype == rsaKey && testecdhe) {
772 		/* TLS_ECDHE_RSA */
773 		ECName       ec_curve;
774 		int		 serverKeyStrengthInBits;
775 		int		 signatureKeyStrength;
776 		int		 requiredECCbits;
777 
778 		/* find a curve of equivalent strength to the RSA key's */
779 		requiredECCbits = PK11_GetPrivateModulusLen(srvPrivkey);
780 		if (requiredECCbits < 0)
781 		    break;
782 		requiredECCbits *= BPB;
783 		serverKeyStrengthInBits = srvPubkey->u.rsa.modulus.len;
784 		if (srvPubkey->u.rsa.modulus.data[0] == 0) {
785 		    serverKeyStrengthInBits--;
786 		}
787 		/* convert to strength in bits */
788 		serverKeyStrengthInBits *= BPB;
789 
790 		signatureKeyStrength =
791 		    SSL_RSASTRENGTH_TO_ECSTRENGTH(serverKeyStrengthInBits);
792 
793 		if ( requiredECCbits > signatureKeyStrength )
794 		     requiredECCbits = signatureKeyStrength;
795 
796 		ec_curve =
797 		    ssl3_GetCurveWithECKeyStrength(
798 					ssl3_GetSupportedECCurveMask(NULL),
799 				  	requiredECCbits);
800 		rv = ssl3_ECName2Params(NULL, ec_curve, &ecParams);
801 		if (rv == SECFailure) {
802 		    break;
803 		}
804 		pecParams = &ecParams;
805 	    }
806 
807 	    if (testecdhe) {
808 		/* generate server's ephemeral keys */
809 		keapriv = SECKEY_CreateECPrivateKey(pecParams, &keapub, NULL);
810 		if (!keapriv || !keapub) {
811 		    if (keapriv)
812 			SECKEY_DestroyPrivateKey(keapriv);
813 		    if (keapub)
814 			SECKEY_DestroyPublicKey(keapub);
815 		    PORT_SetError(SEC_ERROR_KEYGEN_FAIL);
816 		    rv = SECFailure;
817 		    break;
818 		}
819 	    } else {
820 		/* TLS_ECDH_ECDSA */
821 		keapub = srvPubkey;
822 		keapriv = srvPrivkey;
823 		pecParams = &srvPubkey->u.ec.DEREncodedParams;
824 	    }
825 
826 	    /* perform client side ops */
827 	    /* generate a pair of ephemeral keys using server's parms */
828 	    cpriv = SECKEY_CreateECPrivateKey(pecParams, &cpub, NULL);
829 	    if (!cpriv || !cpub) {
830 		if (testecdhe) {
831 		    SECKEY_DestroyPrivateKey(keapriv);
832 		    SECKEY_DestroyPublicKey(keapub);
833 		}
834 		PORT_SetError(SEC_ERROR_KEYGEN_FAIL);
835 		rv = SECFailure;
836 		break;
837 	    }
838 	    /* now do the server side */
839 	    /* determine the PMS using client's public value */
840 	    target = isTLS ? CKM_TLS_MASTER_KEY_DERIVE_DH
841 			   : CKM_SSL3_MASTER_KEY_DERIVE_DH;
842 	    pms = PK11_PubDeriveWithKDF(keapriv, cpub, PR_FALSE, NULL, NULL,
843 				    CKM_ECDH1_DERIVE,
844 				    target,
845 				    CKA_DERIVE, 0, CKD_NULL, NULL, NULL);
846 	    rv = ssl_canExtractMS(pms, isTLS, PR_TRUE, pcanbypass);
847 	    SECKEY_DestroyPrivateKey(cpriv);
848 	    SECKEY_DestroyPublicKey(cpub);
849 	    if (testecdhe) {
850 		SECKEY_DestroyPrivateKey(keapriv);
851 		SECKEY_DestroyPublicKey(keapub);
852 	    }
853 	    if (rv == SECSuccess && *pcanbypass == PR_FALSE)
854 		goto done;
855 	    break;
856 	}
857 	/* Check for NULL to avoid double free. */
858 	if (ecParams.data != NULL) {
859 	    PORT_Free(ecParams.data);
860 	    ecParams.data = NULL;
861 	}
862 #endif /* NSS_ENABLE_ECC */
863 	if (pms)
864 	    PK11_FreeSymKey(pms);
865     }
866 
867     /* *pcanbypass has been set */
868     rv = SECSuccess;
869 
870   done:
871     if (pms)
872 	PK11_FreeSymKey(pms);
873 
874     /* Check for NULL to avoid double free.
875      * SECItem_FreeItem sets data NULL in secitem.c#265
876      */
877     if (enc_pms.data != NULL) {
878     	SECITEM_FreeItem(&enc_pms, PR_FALSE);
879     }
880 #ifdef NSS_ENABLE_ECC
881     if (ecParams.data != NULL) {
882         PORT_Free(ecParams.data);
883         ecParams.data = NULL;
884     }
885 #endif /* NSS_ENABLE_ECC */
886 
887     if (srvPubkey) {
888     	SECKEY_DestroyPublicKey(srvPubkey);
889 	srvPubkey = NULL;
890     }
891 
892 
893     return rv;
894 #endif /* NO_PKCS11_BYPASS */
895 }
896 
897