services/crypto/component/nsSyncJPAKE.cpp@97036ab72558
services/crypto/component/nsSyncJPAKE.cpp
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
1 /* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5 #include "nsSyncJPAKE.h"
6 #include "mozilla/ModuleUtils.h"
7 #include <pk11pub.h>
8 #include <keyhi.h>
9 #include <pkcs11.h>
10 #include <nscore.h>
11 #include <secmodt.h>
12 #include <secport.h>
13 #include <secerr.h>
14 #include <nsDebug.h>
15 #include <nsError.h>
16 #include <base64.h>
17 #include <nsString.h>
19 using mozilla::fallible_t;
21 static bool
22 hex_from_2char(const unsigned char *c2, unsigned char *byteval)
23 {
24 int i;
25 unsigned char offset;
26 *byteval = 0;
27 for (i=0; i<2; i++) {
28 if (c2[i] >= '0' && c2[i] <= '9') {
29 offset = c2[i] - '0';
30 *byteval |= offset << 4*(1-i);
31 } else if (c2[i] >= 'a' && c2[i] <= 'f') {
32 offset = c2[i] - 'a';
33 *byteval |= (offset + 10) << 4*(1-i);
34 } else if (c2[i] >= 'A' && c2[i] <= 'F') {
35 offset = c2[i] - 'A';
36 *byteval |= (offset + 10) << 4*(1-i);
37 } else {
38 return false;
39 }
40 }
41 return true;
42 }
44 static bool
45 fromHex(const char * str, unsigned char * p, size_t sLen)
46 {
47 size_t i;
48 if (sLen & 1)
49 return false;
51 for (i = 0; i < sLen / 2; ++i) {
52 if (!hex_from_2char((const unsigned char *) str + (2*i),
53 (unsigned char *) p + i)) {
54 return false;
55 }
56 }
57 return true;
58 }
60 static nsresult
61 fromHexString(const nsACString & str, unsigned char * p, size_t pMaxLen)
62 {
63 char * strData = (char *) str.Data();
64 unsigned len = str.Length();
65 NS_ENSURE_ARG(len / 2 <= pMaxLen);
66 if (!fromHex(strData, p, len)) {
67 return NS_ERROR_INVALID_ARG;
68 }
69 return NS_OK;
70 }
72 static bool
73 toHexString(const unsigned char * str, unsigned len, nsACString & out)
74 {
75 static const char digits[] = "0123456789ABCDEF";
76 if (!out.SetCapacity(2 * len, fallible_t()))
77 return false;
78 out.SetLength(0);
79 for (unsigned i = 0; i < len; ++i) {
80 out.Append(digits[str[i] >> 4]);
81 out.Append(digits[str[i] & 0x0f]);
82 }
83 return true;
84 }
86 static nsresult
87 mapErrno()
88 {
89 int err = PORT_GetError();
90 switch (err) {
91 case SEC_ERROR_NO_MEMORY: return NS_ERROR_OUT_OF_MEMORY;
92 default: return NS_ERROR_UNEXPECTED;
93 }
94 }
96 #define NUM_ELEM(x) (sizeof(x) / sizeof (x)[0])
98 static const char p[] =
99 "90066455B5CFC38F9CAA4A48B4281F292C260FEEF01FD61037E56258A7795A1C"
100 "7AD46076982CE6BB956936C6AB4DCFE05E6784586940CA544B9B2140E1EB523F"
101 "009D20A7E7880E4E5BFA690F1B9004A27811CD9904AF70420EEFD6EA11EF7DA1"
102 "29F58835FF56B89FAA637BC9AC2EFAAB903402229F491D8D3485261CD068699B"
103 "6BA58A1DDBBEF6DB51E8FE34E8A78E542D7BA351C21EA8D8F1D29F5D5D159394"
104 "87E27F4416B0CA632C59EFD1B1EB66511A5A0FBF615B766C5862D0BD8A3FE7A0"
105 "E0DA0FB2FE1FCB19E8F9996A8EA0FCCDE538175238FC8B0EE6F29AF7F642773E"
106 "BE8CD5402415A01451A840476B2FCEB0E388D30D4B376C37FE401C2A2C2F941D"
107 "AD179C540C1C8CE030D460C4D983BE9AB0B20F69144C1AE13F9383EA1C08504F"
108 "B0BF321503EFE43488310DD8DC77EC5B8349B8BFE97C2C560EA878DE87C11E3D"
109 "597F1FEA742D73EEC7F37BE43949EF1A0D15C3F3E3FC0A8335617055AC91328E"
110 "C22B50FC15B941D3D1624CD88BC25F3E941FDDC6200689581BFEC416B4B2CB73";
111 static const char q[] =
112 "CFA0478A54717B08CE64805B76E5B14249A77A4838469DF7F7DC987EFCCFB11D";
113 static const char g[] =
114 "5E5CBA992E0A680D885EB903AEA78E4A45A469103D448EDE3B7ACCC54D521E37"
115 "F84A4BDD5B06B0970CC2D2BBB715F7B82846F9A0C393914C792E6A923E2117AB"
116 "805276A975AADB5261D91673EA9AAFFEECBFA6183DFCB5D3B7332AA19275AFA1"
117 "F8EC0B60FB6F66CC23AE4870791D5982AAD1AA9485FD8F4A60126FEB2CF05DB8"
118 "A7F0F09B3397F3937F2E90B9E5B9C9B6EFEF642BC48351C46FB171B9BFA9EF17"
119 "A961CE96C7E7A7CC3D3D03DFAD1078BA21DA425198F07D2481622BCE45969D9C"
120 "4D6063D72AB7A0F08B2F49A7CC6AF335E08C4720E31476B67299E231F8BD90B3"
121 "9AC3AE3BE0C6B6CACEF8289A2E2873D58E51E029CAFBD55E6841489AB66B5B4B"
122 "9BA6E2F784660896AFF387D92844CCB8B69475496DE19DA2E58259B090489AC8"
123 "E62363CDF82CFD8EF2A427ABCD65750B506F56DDE3B988567A88126B914D7828"
124 "E2B63A6D7ED0747EC59E0E0A23CE7D8A74C1D2C2A7AFB6A29799620F00E11C33"
125 "787F7DED3B30E1A22D09F1FBDA1ABBBFBF25CAE05A13F812E34563F99410E73B";
127 NS_IMETHODIMP nsSyncJPAKE::Round1(const nsACString & aSignerID,
128 nsACString & aGX1,
129 nsACString & aGV1,
130 nsACString & aR1,
131 nsACString & aGX2,
132 nsACString & aGV2,
133 nsACString & aR2)
134 {
135 NS_ENSURE_STATE(round == JPAKENotStarted);
136 NS_ENSURE_STATE(key == nullptr);
138 static CK_MECHANISM_TYPE mechanisms[] = {
139 CKM_NSS_JPAKE_ROUND1_SHA256,
140 CKM_NSS_JPAKE_ROUND2_SHA256,
141 CKM_NSS_JPAKE_FINAL_SHA256
142 };
144 PK11SlotInfo * slot = PK11_GetBestSlotMultiple(mechanisms,
145 NUM_ELEM(mechanisms),
146 nullptr);
147 NS_ENSURE_STATE(slot != nullptr);
149 CK_BYTE pBuf[(NUM_ELEM(p) - 1) / 2];
150 CK_BYTE qBuf[(NUM_ELEM(q) - 1) / 2];
151 CK_BYTE gBuf[(NUM_ELEM(g) - 1) / 2];
153 CK_KEY_TYPE keyType = CKK_NSS_JPAKE_ROUND1;
154 NS_ENSURE_STATE(fromHex(p, pBuf, (NUM_ELEM(p) - 1)));
155 NS_ENSURE_STATE(fromHex(q, qBuf, (NUM_ELEM(q) - 1)));
156 NS_ENSURE_STATE(fromHex(g, gBuf, (NUM_ELEM(g) - 1)));
157 CK_ATTRIBUTE keyTemplate[] = {
158 { CKA_NSS_JPAKE_SIGNERID, (CK_BYTE *) aSignerID.Data(),
159 aSignerID.Length() },
160 { CKA_KEY_TYPE, &keyType, sizeof keyType },
161 { CKA_PRIME, pBuf, sizeof pBuf },
162 { CKA_SUBPRIME, qBuf, sizeof qBuf },
163 { CKA_BASE, gBuf, sizeof gBuf }
164 };
166 CK_BYTE gx1Buf[NUM_ELEM(p) / 2];
167 CK_BYTE gv1Buf[NUM_ELEM(p) / 2];
168 CK_BYTE r1Buf [NUM_ELEM(p) / 2];
169 CK_BYTE gx2Buf[NUM_ELEM(p) / 2];
170 CK_BYTE gv2Buf[NUM_ELEM(p) / 2];
171 CK_BYTE r2Buf [NUM_ELEM(p) / 2];
172 CK_NSS_JPAKERound1Params rp = {
173 { gx1Buf, sizeof gx1Buf, gv1Buf, sizeof gv1Buf, r1Buf, sizeof r1Buf },
174 { gx2Buf, sizeof gx2Buf, gv2Buf, sizeof gv2Buf, r2Buf, sizeof r2Buf }
175 };
176 SECItem paramsItem;
177 paramsItem.data = (unsigned char *) &rp;
178 paramsItem.len = sizeof rp;
179 key = PK11_KeyGenWithTemplate(slot, CKM_NSS_JPAKE_ROUND1_SHA256,
180 CKM_NSS_JPAKE_ROUND1_SHA256,
181 ¶msItem, keyTemplate,
182 NUM_ELEM(keyTemplate), nullptr);
183 nsresult rv = key != nullptr
184 ? NS_OK
185 : mapErrno();
186 if (rv == NS_OK) {
187 NS_ENSURE_TRUE(toHexString(rp.gx1.pGX, rp.gx1.ulGXLen, aGX1) &&
188 toHexString(rp.gx1.pGV, rp.gx1.ulGVLen, aGV1) &&
189 toHexString(rp.gx1.pR, rp.gx1.ulRLen, aR1) &&
190 toHexString(rp.gx2.pGX, rp.gx2.ulGXLen, aGX2) &&
191 toHexString(rp.gx2.pGV, rp.gx2.ulGVLen, aGV2) &&
192 toHexString(rp.gx2.pR, rp.gx2.ulRLen, aR2),
193 NS_ERROR_OUT_OF_MEMORY);
194 round = JPAKEBeforeRound2;
195 }
196 return rv;
197 }
199 NS_IMETHODIMP nsSyncJPAKE::Round2(const nsACString & aPeerID,
200 const nsACString & aPIN,
201 const nsACString & aGX3,
202 const nsACString & aGV3,
203 const nsACString & aR3,
204 const nsACString & aGX4,
205 const nsACString & aGV4,
206 const nsACString & aR4,
207 nsACString & aA,
208 nsACString & aGVA,
209 nsACString & aRA)
210 {
211 NS_ENSURE_STATE(round == JPAKEBeforeRound2);
212 NS_ENSURE_STATE(key != nullptr);
213 NS_ENSURE_ARG(!aPeerID.IsEmpty());
215 /* PIN cannot be equal to zero when converted to a bignum. NSS 3.12.9 J-PAKE
216 assumes that the caller has already done this check. Future versions of
217 NSS J-PAKE will do this check internally. See Bug 609068 Comment 4 */
218 bool foundNonZero = false;
219 for (size_t i = 0; i < aPIN.Length(); ++i) {
220 if (aPIN[i] != 0) {
221 foundNonZero = true;
222 break;
223 }
224 }
225 NS_ENSURE_ARG(foundNonZero);
227 CK_BYTE gx3Buf[NUM_ELEM(p)/2], gv3Buf[NUM_ELEM(p)/2], r3Buf [NUM_ELEM(p)/2];
228 CK_BYTE gx4Buf[NUM_ELEM(p)/2], gv4Buf[NUM_ELEM(p)/2], r4Buf [NUM_ELEM(p)/2];
229 CK_BYTE gxABuf[NUM_ELEM(p)/2], gvABuf[NUM_ELEM(p)/2], rABuf [NUM_ELEM(p)/2];
230 nsresult rv = fromHexString(aGX3, gx3Buf, sizeof gx3Buf);
231 if (rv == NS_OK) rv = fromHexString(aGV3, gv3Buf, sizeof gv3Buf);
232 if (rv == NS_OK) rv = fromHexString(aR3, r3Buf, sizeof r3Buf);
233 if (rv == NS_OK) rv = fromHexString(aGX4, gx4Buf, sizeof gx4Buf);
234 if (rv == NS_OK) rv = fromHexString(aGV4, gv4Buf, sizeof gv4Buf);
235 if (rv == NS_OK) rv = fromHexString(aR4, r4Buf, sizeof r4Buf);
236 if (rv != NS_OK)
237 return rv;
239 CK_NSS_JPAKERound2Params rp;
240 rp.pSharedKey = (CK_BYTE *) aPIN.Data();
241 rp.ulSharedKeyLen = aPIN.Length();
242 rp.gx3.pGX = gx3Buf; rp.gx3.ulGXLen = aGX3.Length() / 2;
243 rp.gx3.pGV = gv3Buf; rp.gx3.ulGVLen = aGV3.Length() / 2;
244 rp.gx3.pR = r3Buf; rp.gx3.ulRLen = aR3 .Length() / 2;
245 rp.gx4.pGX = gx4Buf; rp.gx4.ulGXLen = aGX4.Length() / 2;
246 rp.gx4.pGV = gv4Buf; rp.gx4.ulGVLen = aGV4.Length() / 2;
247 rp.gx4.pR = r4Buf; rp.gx4.ulRLen = aR4 .Length() / 2;
248 rp.A.pGX = gxABuf; rp.A .ulGXLen = sizeof gxABuf;
249 rp.A.pGV = gvABuf; rp.A .ulGVLen = sizeof gxABuf;
250 rp.A.pR = rABuf; rp.A .ulRLen = sizeof gxABuf;
252 // Bug 629090: NSS 3.12.9 J-PAKE fails to check that gx^4 != 1, so check here.
253 bool gx4Good = false;
254 for (unsigned i = 0; i < rp.gx4.ulGXLen; ++i) {
255 if (rp.gx4.pGX[i] > 1 || (rp.gx4.pGX[i] != 0 && i < rp.gx4.ulGXLen - 1)) {
256 gx4Good = true;
257 break;
258 }
259 }
260 NS_ENSURE_ARG(gx4Good);
262 SECItem paramsItem;
263 paramsItem.data = (unsigned char *) &rp;
264 paramsItem.len = sizeof rp;
265 CK_KEY_TYPE keyType = CKK_NSS_JPAKE_ROUND2;
266 CK_ATTRIBUTE keyTemplate[] = {
267 { CKA_NSS_JPAKE_PEERID, (CK_BYTE *) aPeerID.Data(), aPeerID.Length(), },
268 { CKA_KEY_TYPE, &keyType, sizeof keyType }
269 };
270 PK11SymKey * newKey = PK11_DeriveWithTemplate(key,
271 CKM_NSS_JPAKE_ROUND2_SHA256,
272 ¶msItem,
273 CKM_NSS_JPAKE_FINAL_SHA256,
274 CKA_DERIVE, 0,
275 keyTemplate,
276 NUM_ELEM(keyTemplate),
277 false);
278 if (newKey != nullptr) {
279 if (toHexString(rp.A.pGX, rp.A.ulGXLen, aA) &&
280 toHexString(rp.A.pGV, rp.A.ulGVLen, aGVA) &&
281 toHexString(rp.A.pR, rp.A.ulRLen, aRA)) {
282 round = JPAKEAfterRound2;
283 PK11_FreeSymKey(key);
284 key = newKey;
285 return NS_OK;
286 } else {
287 PK11_FreeSymKey(newKey);
288 rv = NS_ERROR_OUT_OF_MEMORY;
289 }
290 } else
291 rv = mapErrno();
293 return rv;
294 }
296 static nsresult
297 setBase64(const unsigned char * data, unsigned len, nsACString & out)
298 {
299 nsresult rv = NS_OK;
300 const char * base64 = BTOA_DataToAscii(data, len);
302 if (base64 != nullptr) {
303 size_t len = PORT_Strlen(base64);
304 if (out.SetCapacity(len, fallible_t())) {
305 out.SetLength(0);
306 out.Append(base64, len);
307 PORT_Free((void*) base64);
308 } else {
309 rv = NS_ERROR_OUT_OF_MEMORY;
310 }
311 } else {
312 rv = NS_ERROR_OUT_OF_MEMORY;
313 }
314 return rv;
315 }
317 static nsresult
318 base64KeyValue(PK11SymKey * key, nsACString & keyString)
319 {
320 nsresult rv = NS_OK;
321 if (PK11_ExtractKeyValue(key) == SECSuccess) {
322 const SECItem * value = PK11_GetKeyData(key);
323 rv = value != nullptr && value->data != nullptr && value->len > 0
324 ? setBase64(value->data, value->len, keyString)
325 : NS_ERROR_UNEXPECTED;
326 } else {
327 rv = mapErrno();
328 }
329 return rv;
330 }
332 static nsresult
333 extractBase64KeyValue(PK11SymKey * keyBlock, CK_ULONG bitPosition,
334 CK_MECHANISM_TYPE destMech, int keySize,
335 nsACString & keyString)
336 {
337 SECItem paramsItem;
338 paramsItem.data = (CK_BYTE *) &bitPosition;
339 paramsItem.len = sizeof bitPosition;
340 PK11SymKey * key = PK11_Derive(keyBlock, CKM_EXTRACT_KEY_FROM_KEY,
341 ¶msItem, destMech,
342 CKA_SIGN, keySize);
343 if (key == nullptr)
344 return mapErrno();
345 nsresult rv = base64KeyValue(key, keyString);
346 PK11_FreeSymKey(key);
347 return rv;
348 }
351 NS_IMETHODIMP nsSyncJPAKE::Final(const nsACString & aB,
352 const nsACString & aGVB,
353 const nsACString & aRB,
354 const nsACString & aHKDFInfo,
355 nsACString & aAES256Key,
356 nsACString & aHMAC256Key)
357 {
358 static const unsigned AES256_KEY_SIZE = 256 / 8;
359 static const unsigned HMAC_SHA256_KEY_SIZE = 256 / 8;
360 CK_EXTRACT_PARAMS aesBitPosition = 0;
361 CK_EXTRACT_PARAMS hmacBitPosition = aesBitPosition + (AES256_KEY_SIZE * 8);
363 NS_ENSURE_STATE(round == JPAKEAfterRound2);
364 NS_ENSURE_STATE(key != nullptr);
366 CK_BYTE gxBBuf[NUM_ELEM(p)/2], gvBBuf[NUM_ELEM(p)/2], rBBuf [NUM_ELEM(p)/2];
367 nsresult rv = fromHexString(aB, gxBBuf, sizeof gxBBuf);
368 if (rv == NS_OK) rv = fromHexString(aGVB, gvBBuf, sizeof gvBBuf);
369 if (rv == NS_OK) rv = fromHexString(aRB, rBBuf, sizeof rBBuf);
370 if (rv != NS_OK)
371 return rv;
373 CK_NSS_JPAKEFinalParams rp;
374 rp.B.pGX = gxBBuf; rp.B.ulGXLen = aB .Length() / 2;
375 rp.B.pGV = gvBBuf; rp.B.ulGVLen = aGVB.Length() / 2;
376 rp.B.pR = rBBuf; rp.B.ulRLen = aRB .Length() / 2;
377 SECItem paramsItem;
378 paramsItem.data = (unsigned char *) &rp;
379 paramsItem.len = sizeof rp;
380 PK11SymKey * keyMaterial = PK11_Derive(key, CKM_NSS_JPAKE_FINAL_SHA256,
381 ¶msItem, CKM_NSS_HKDF_SHA256,
382 CKA_DERIVE, 0);
383 PK11SymKey * keyBlock = nullptr;
385 if (keyMaterial == nullptr)
386 rv = mapErrno();
388 if (rv == NS_OK) {
389 CK_NSS_HKDFParams hkdfParams;
390 hkdfParams.bExtract = CK_TRUE;
391 hkdfParams.pSalt = nullptr;
392 hkdfParams.ulSaltLen = 0;
393 hkdfParams.bExpand = CK_TRUE;
394 hkdfParams.pInfo = (CK_BYTE *) aHKDFInfo.Data();
395 hkdfParams.ulInfoLen = aHKDFInfo.Length();
396 paramsItem.data = (unsigned char *) &hkdfParams;
397 paramsItem.len = sizeof hkdfParams;
398 keyBlock = PK11_Derive(keyMaterial, CKM_NSS_HKDF_SHA256,
399 ¶msItem, CKM_EXTRACT_KEY_FROM_KEY,
400 CKA_DERIVE, AES256_KEY_SIZE + HMAC_SHA256_KEY_SIZE);
401 if (keyBlock == nullptr)
402 rv = mapErrno();
403 }
405 if (rv == NS_OK) {
406 rv = extractBase64KeyValue(keyBlock, aesBitPosition, CKM_AES_CBC,
407 AES256_KEY_SIZE, aAES256Key);
408 }
409 if (rv == NS_OK) {
410 rv = extractBase64KeyValue(keyBlock, hmacBitPosition, CKM_SHA256_HMAC,
411 HMAC_SHA256_KEY_SIZE, aHMAC256Key);
412 }
414 if (rv == NS_OK) {
415 SECStatus srv = PK11_ExtractKeyValue(keyMaterial);
416 NS_ENSURE_TRUE(srv == SECSuccess, NS_ERROR_UNEXPECTED); // XXX leaks
417 SECItem * keyMaterialBytes = PK11_GetKeyData(keyMaterial);
418 NS_ENSURE_TRUE(keyMaterialBytes != nullptr, NS_ERROR_UNEXPECTED);
419 }
421 if (keyBlock != nullptr)
422 PK11_FreeSymKey(keyBlock);
423 if (keyMaterial != nullptr)
424 PK11_FreeSymKey(keyMaterial);
426 return rv;
427 }
429 NS_GENERIC_FACTORY_CONSTRUCTOR(nsSyncJPAKE)
430 NS_DEFINE_NAMED_CID(NS_SYNCJPAKE_CID);
432 nsSyncJPAKE::nsSyncJPAKE() : round(JPAKENotStarted), key(nullptr) { }
434 nsSyncJPAKE::~nsSyncJPAKE()
435 {
436 if (key != nullptr)
437 PK11_FreeSymKey(key);
438 }
440 static const mozilla::Module::CIDEntry kServicesCryptoCIDs[] = {
441 { &kNS_SYNCJPAKE_CID, false, nullptr, nsSyncJPAKEConstructor },
442 { nullptr }
443 };
445 static const mozilla::Module::ContractIDEntry kServicesCryptoContracts[] = {
446 { NS_SYNCJPAKE_CONTRACTID, &kNS_SYNCJPAKE_CID },
447 { nullptr }
448 };
450 static const mozilla::Module kServicesCryptoModule = {
451 mozilla::Module::kVersion,
452 kServicesCryptoCIDs,
453 kServicesCryptoContracts
454 };
456 NSMODULE_DEFN(nsServicesCryptoModule) = &kServicesCryptoModule;
