1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "keystore.h"
18
19#include <dirent.h>
20#include <fcntl.h>
21
22#include <openssl/bio.h>
23
24#include <utils/String16.h>
25
26#include <keystore/IKeystoreService.h>
27
28#include "keystore_utils.h"
29#include "permissions.h"
30
31const char* KeyStore::sOldMasterKey = ".masterkey";
32const char* KeyStore::sMetaDataFile = ".metadata";
33
34const android::String16 KeyStore::sRSAKeyType("RSA");
35
36KeyStore::KeyStore(Entropy* entropy, keymaster2_device_t* device, keymaster2_device_t* fallback)
37    : mEntropy(entropy), mDevice(device), mFallbackDevice(fallback) {
38    memset(&mMetaData, '\0', sizeof(mMetaData));
39}
40
41KeyStore::~KeyStore() {
42    for (android::Vector<grant_t*>::iterator it(mGrants.begin()); it != mGrants.end(); it++) {
43        delete *it;
44    }
45    mGrants.clear();
46
47    for (android::Vector<UserState*>::iterator it(mMasterKeys.begin()); it != mMasterKeys.end();
48         it++) {
49        delete *it;
50    }
51    mMasterKeys.clear();
52}
53
54ResponseCode KeyStore::initialize() {
55    readMetaData();
56    if (upgradeKeystore()) {
57        writeMetaData();
58    }
59
60    return ::NO_ERROR;
61}
62
63ResponseCode KeyStore::initializeUser(const android::String8& pw, uid_t userId) {
64    UserState* userState = getUserState(userId);
65    return userState->initialize(pw, mEntropy);
66}
67
68ResponseCode KeyStore::copyMasterKey(uid_t srcUser, uid_t dstUser) {
69    UserState* userState = getUserState(dstUser);
70    UserState* initState = getUserState(srcUser);
71    return userState->copyMasterKey(initState);
72}
73
74ResponseCode KeyStore::writeMasterKey(const android::String8& pw, uid_t userId) {
75    UserState* userState = getUserState(userId);
76    return userState->writeMasterKey(pw, mEntropy);
77}
78
79ResponseCode KeyStore::readMasterKey(const android::String8& pw, uid_t userId) {
80    UserState* userState = getUserState(userId);
81    return userState->readMasterKey(pw, mEntropy);
82}
83
84/* Here is the encoding of keys. This is necessary in order to allow arbitrary
85 * characters in keys. Characters in [0-~] are not encoded. Others are encoded
86 * into two bytes. The first byte is one of [+-.] which represents the first
87 * two bits of the character. The second byte encodes the rest of the bits into
88 * [0-o]. Therefore in the worst case the length of a key gets doubled. Note
89 * that Base64 cannot be used here due to the need of prefix match on keys. */
90
91static size_t encode_key_length(const android::String8& keyName) {
92    const uint8_t* in = reinterpret_cast<const uint8_t*>(keyName.string());
93    size_t length = keyName.length();
94    for (int i = length; i > 0; --i, ++in) {
95        if (*in < '0' || *in > '~') {
96            ++length;
97        }
98    }
99    return length;
100}
101
102static int encode_key(char* out, const android::String8& keyName) {
103    const uint8_t* in = reinterpret_cast<const uint8_t*>(keyName.string());
104    size_t length = keyName.length();
105    for (int i = length; i > 0; --i, ++in, ++out) {
106        if (*in < '0' || *in > '~') {
107            *out = '+' + (*in >> 6);
108            *++out = '0' + (*in & 0x3F);
109            ++length;
110        } else {
111            *out = *in;
112        }
113    }
114    *out = '\0';
115    return length;
116}
117
118android::String8 KeyStore::getKeyName(const android::String8& keyName, const BlobType type) {
119    char encoded[encode_key_length(keyName) + 1];  // add 1 for null char
120    encode_key(encoded, keyName);
121    if (type == TYPE_KEY_CHARACTERISTICS) {
122        return android::String8::format(".chr_%s", encoded);
123    } else {
124        return android::String8(encoded);
125    }
126}
127
128android::String8 KeyStore::getKeyNameForUid(
129    const android::String8& keyName, uid_t uid, const BlobType type) {
130    char encoded[encode_key_length(keyName) + 1];  // add 1 for null char
131    encode_key(encoded, keyName);
132    if (type == TYPE_KEY_CHARACTERISTICS) {
133        return android::String8::format(".%u_chr_%s", uid, encoded);
134    } else {
135        return android::String8::format("%u_%s", uid, encoded);
136    }
137}
138
139android::String8 KeyStore::getKeyNameForUidWithDir(
140    const android::String8& keyName, uid_t uid, const BlobType type) {
141    char encoded[encode_key_length(keyName) + 1];  // add 1 for null char
142    encode_key(encoded, keyName);
143
144    if (type == TYPE_KEY_CHARACTERISTICS) {
145        return android::String8::format("%s/.%u_chr_%s", getUserStateByUid(uid)->getUserDirName(),
146                                        uid, encoded);
147    } else {
148        return android::String8::format("%s/%u_%s", getUserStateByUid(uid)->getUserDirName(), uid,
149                                        encoded);
150    }
151}
152
153void KeyStore::resetUser(uid_t userId, bool keepUnenryptedEntries) {
154    android::String8 prefix("");
155    android::Vector<android::String16> aliases;
156    UserState* userState = getUserState(userId);
157    if (list(prefix, &aliases, userId) != ::NO_ERROR) {
158        return;
159    }
160    for (uint32_t i = 0; i < aliases.size(); i++) {
161        android::String8 filename(aliases[i]);
162        filename = android::String8::format("%s/%s", userState->getUserDirName(),
163                                            getKeyName(filename, TYPE_ANY).string());
164        bool shouldDelete = true;
165        if (keepUnenryptedEntries) {
166            Blob blob;
167            ResponseCode rc = get(filename, &blob, ::TYPE_ANY, userId);
168
169            /* get can fail if the blob is encrypted and the state is
170             * not unlocked, only skip deleting blobs that were loaded and
171             * who are not encrypted. If there are blobs we fail to read for
172             * other reasons err on the safe side and delete them since we
173             * can't tell if they're encrypted.
174             */
175            shouldDelete = !(rc == ::NO_ERROR && !blob.isEncrypted());
176        }
177        if (shouldDelete) {
178            del(filename, ::TYPE_ANY, userId);
179
180            // del() will fail silently if no cached characteristics are present for this alias.
181            android::String8 chr_filename(aliases[i]);
182            chr_filename = android::String8::format("%s/%s", userState->getUserDirName(),
183                                            getKeyName(chr_filename,
184                                                TYPE_KEY_CHARACTERISTICS).string());
185            del(chr_filename, ::TYPE_KEY_CHARACTERISTICS, userId);
186        }
187    }
188    if (!userState->deleteMasterKey()) {
189        ALOGE("Failed to delete user %d's master key", userId);
190    }
191    if (!keepUnenryptedEntries) {
192        if (!userState->reset()) {
193            ALOGE("Failed to remove user %d's directory", userId);
194        }
195    }
196}
197
198bool KeyStore::isEmpty(uid_t userId) const {
199    const UserState* userState = getUserState(userId);
200    if (userState == NULL) {
201        return true;
202    }
203
204    DIR* dir = opendir(userState->getUserDirName());
205    if (!dir) {
206        return true;
207    }
208
209    bool result = true;
210    struct dirent* file;
211    while ((file = readdir(dir)) != NULL) {
212        // We only care about files.
213        if (file->d_type != DT_REG) {
214            continue;
215        }
216
217        // Skip anything that starts with a "."
218        if (file->d_name[0] == '.') {
219            continue;
220        }
221
222        result = false;
223        break;
224    }
225    closedir(dir);
226    return result;
227}
228
229void KeyStore::lock(uid_t userId) {
230    UserState* userState = getUserState(userId);
231    userState->zeroizeMasterKeysInMemory();
232    userState->setState(STATE_LOCKED);
233}
234
235ResponseCode KeyStore::get(const char* filename, Blob* keyBlob, const BlobType type, uid_t userId) {
236    UserState* userState = getUserState(userId);
237    ResponseCode rc =
238        keyBlob->readBlob(filename, userState->getDecryptionKey(), userState->getState());
239    if (rc != NO_ERROR) {
240        return rc;
241    }
242
243    const uint8_t version = keyBlob->getVersion();
244    if (version < CURRENT_BLOB_VERSION) {
245        /* If we upgrade the key, we need to write it to disk again. Then
246         * it must be read it again since the blob is encrypted each time
247         * it's written.
248         */
249        if (upgradeBlob(filename, keyBlob, version, type, userId)) {
250            if ((rc = this->put(filename, keyBlob, userId)) != NO_ERROR ||
251                (rc = keyBlob->readBlob(filename, userState->getDecryptionKey(),
252                                        userState->getState())) != NO_ERROR) {
253                return rc;
254            }
255        }
256    }
257
258    /*
259     * This will upgrade software-backed keys to hardware-backed keys when
260     * the HAL for the device supports the newer key types.
261     */
262    if (rc == NO_ERROR && type == TYPE_KEY_PAIR &&
263        mDevice->common.module->module_api_version >= KEYMASTER_MODULE_API_VERSION_0_2 &&
264        keyBlob->isFallback()) {
265        ResponseCode imported =
266            importKey(keyBlob->getValue(), keyBlob->getLength(), filename, userId,
267                      keyBlob->isEncrypted() ? KEYSTORE_FLAG_ENCRYPTED : KEYSTORE_FLAG_NONE);
268
269        // The HAL allowed the import, reget the key to have the "fresh"
270        // version.
271        if (imported == NO_ERROR) {
272            rc = get(filename, keyBlob, TYPE_KEY_PAIR, userId);
273        }
274    }
275
276    // Keymaster 0.3 keys are valid keymaster 1.0 keys, so silently upgrade.
277    if (keyBlob->getType() == TYPE_KEY_PAIR) {
278        keyBlob->setType(TYPE_KEYMASTER_10);
279        rc = this->put(filename, keyBlob, userId);
280    }
281
282    if (type != TYPE_ANY && keyBlob->getType() != type) {
283        ALOGW("key found but type doesn't match: %d vs %d", keyBlob->getType(), type);
284        return KEY_NOT_FOUND;
285    }
286
287    return rc;
288}
289
290ResponseCode KeyStore::put(const char* filename, Blob* keyBlob, uid_t userId) {
291    UserState* userState = getUserState(userId);
292    return keyBlob->writeBlob(filename, userState->getEncryptionKey(), userState->getState(),
293                              mEntropy);
294}
295
296ResponseCode KeyStore::del(const char* filename, const BlobType type, uid_t userId) {
297    Blob keyBlob;
298    ResponseCode rc = get(filename, &keyBlob, type, userId);
299    if (rc == ::VALUE_CORRUPTED) {
300        // The file is corrupt, the best we can do is rm it.
301        return (unlink(filename) && errno != ENOENT) ? ::SYSTEM_ERROR : ::NO_ERROR;
302    }
303    if (rc != ::NO_ERROR) {
304        return rc;
305    }
306
307    if (keyBlob.getType() == ::TYPE_KEY_PAIR) {
308        // A device doesn't have to implement delete_key.
309        if (mDevice->delete_key != NULL && !keyBlob.isFallback()) {
310            keymaster_key_blob_t blob = {keyBlob.getValue(),
311                                         static_cast<size_t>(keyBlob.getLength())};
312            if (mDevice->delete_key(mDevice, &blob)) {
313                rc = ::SYSTEM_ERROR;
314            }
315        }
316    }
317    if (keyBlob.getType() == ::TYPE_KEYMASTER_10) {
318        auto* dev = getDeviceForBlob(keyBlob);
319        if (dev->delete_key) {
320            keymaster_key_blob_t blob;
321            blob.key_material = keyBlob.getValue();
322            blob.key_material_size = keyBlob.getLength();
323            dev->delete_key(dev, &blob);
324        }
325    }
326    if (rc != ::NO_ERROR) {
327        return rc;
328    }
329
330    return (unlink(filename) && errno != ENOENT) ? ::SYSTEM_ERROR : ::NO_ERROR;
331}
332
333/*
334 * Converts from the "escaped" format on disk to actual name.
335 * This will be smaller than the input string.
336 *
337 * Characters that should combine with the next at the end will be truncated.
338 */
339static size_t decode_key_length(const char* in, size_t length) {
340    size_t outLength = 0;
341
342    for (const char* end = in + length; in < end; in++) {
343        /* This combines with the next character. */
344        if (*in < '0' || *in > '~') {
345            continue;
346        }
347
348        outLength++;
349    }
350    return outLength;
351}
352
353static void decode_key(char* out, const char* in, size_t length) {
354    for (const char* end = in + length; in < end; in++) {
355        if (*in < '0' || *in > '~') {
356            /* Truncate combining characters at the end. */
357            if (in + 1 >= end) {
358                break;
359            }
360
361            *out = (*in++ - '+') << 6;
362            *out++ |= (*in - '0') & 0x3F;
363        } else {
364            *out++ = *in;
365        }
366    }
367    *out = '\0';
368}
369
370ResponseCode KeyStore::list(const android::String8& prefix,
371                            android::Vector<android::String16>* matches, uid_t userId) {
372
373    UserState* userState = getUserState(userId);
374    size_t n = prefix.length();
375
376    DIR* dir = opendir(userState->getUserDirName());
377    if (!dir) {
378        ALOGW("can't open directory for user: %s", strerror(errno));
379        return ::SYSTEM_ERROR;
380    }
381
382    struct dirent* file;
383    while ((file = readdir(dir)) != NULL) {
384        // We only care about files.
385        if (file->d_type != DT_REG) {
386            continue;
387        }
388
389        // Skip anything that starts with a "."
390        if (file->d_name[0] == '.') {
391            continue;
392        }
393
394        if (!strncmp(prefix.string(), file->d_name, n)) {
395            const char* p = &file->d_name[n];
396            size_t plen = strlen(p);
397
398            size_t extra = decode_key_length(p, plen);
399            char* match = (char*)malloc(extra + 1);
400            if (match != NULL) {
401                decode_key(match, p, plen);
402                matches->push(android::String16(match, extra));
403                free(match);
404            } else {
405                ALOGW("could not allocate match of size %zd", extra);
406            }
407        }
408    }
409    closedir(dir);
410    return ::NO_ERROR;
411}
412
413void KeyStore::addGrant(const char* filename, uid_t granteeUid) {
414    const grant_t* existing = getGrant(filename, granteeUid);
415    if (existing == NULL) {
416        grant_t* grant = new grant_t;
417        grant->uid = granteeUid;
418        grant->filename = reinterpret_cast<const uint8_t*>(strdup(filename));
419        mGrants.add(grant);
420    }
421}
422
423bool KeyStore::removeGrant(const char* filename, uid_t granteeUid) {
424    for (android::Vector<grant_t*>::iterator it(mGrants.begin()); it != mGrants.end(); it++) {
425        grant_t* grant = *it;
426        if (grant->uid == granteeUid &&
427            !strcmp(reinterpret_cast<const char*>(grant->filename), filename)) {
428            mGrants.erase(it);
429            return true;
430        }
431    }
432    return false;
433}
434
435ResponseCode KeyStore::importKey(const uint8_t* key, size_t keyLen, const char* filename,
436                                 uid_t userId, int32_t flags) {
437    Unique_PKCS8_PRIV_KEY_INFO pkcs8(d2i_PKCS8_PRIV_KEY_INFO(NULL, &key, keyLen));
438    if (!pkcs8.get()) {
439        return ::SYSTEM_ERROR;
440    }
441    Unique_EVP_PKEY pkey(EVP_PKCS82PKEY(pkcs8.get()));
442    if (!pkey.get()) {
443        return ::SYSTEM_ERROR;
444    }
445    int type = EVP_PKEY_type(pkey->type);
446    android::KeymasterArguments params;
447    add_legacy_key_authorizations(type, &params.params);
448    switch (type) {
449    case EVP_PKEY_RSA:
450        params.params.push_back(keymaster_param_enum(KM_TAG_ALGORITHM, KM_ALGORITHM_RSA));
451        break;
452    case EVP_PKEY_EC:
453        params.params.push_back(keymaster_param_enum(KM_TAG_ALGORITHM, KM_ALGORITHM_EC));
454        break;
455    default:
456        ALOGW("Unsupported key type %d", type);
457        return ::SYSTEM_ERROR;
458    }
459
460    std::vector<keymaster_key_param_t> opParams(params.params);
461    const keymaster_key_param_set_t inParams = {opParams.data(), opParams.size()};
462    keymaster_blob_t input = {key, keyLen};
463    keymaster_key_blob_t blob = {nullptr, 0};
464    bool isFallback = false;
465    keymaster_error_t error = mDevice->import_key(mDevice, &inParams, KM_KEY_FORMAT_PKCS8, &input,
466                                                  &blob, NULL /* characteristics */);
467    if (error != KM_ERROR_OK) {
468        ALOGE("Keymaster error %d importing key pair, falling back", error);
469
470        /*
471         * There should be no way to get here.  Fallback shouldn't ever really happen
472         * because the main device may be many (SW, KM0/SW hybrid, KM1/SW hybrid), but it must
473         * provide full support of the API.  In any case, we'll do the fallback just for
474         * consistency... and I suppose to cover for broken HW implementations.
475         */
476        error = mFallbackDevice->import_key(mFallbackDevice, &inParams, KM_KEY_FORMAT_PKCS8, &input,
477                                            &blob, NULL /* characteristics */);
478        isFallback = true;
479
480        if (error) {
481            ALOGE("Keymaster error while importing key pair with fallback: %d", error);
482            return SYSTEM_ERROR;
483        }
484    }
485
486    Blob keyBlob(blob.key_material, blob.key_material_size, NULL, 0, TYPE_KEYMASTER_10);
487    free(const_cast<uint8_t*>(blob.key_material));
488
489    keyBlob.setEncrypted(flags & KEYSTORE_FLAG_ENCRYPTED);
490    keyBlob.setFallback(isFallback);
491
492    return put(filename, &keyBlob, userId);
493}
494
495bool KeyStore::isHardwareBacked(const android::String16& keyType) const {
496    if (mDevice == NULL) {
497        ALOGW("can't get keymaster device");
498        return false;
499    }
500
501    if (sRSAKeyType == keyType) {
502        return (mDevice->flags & KEYMASTER_SOFTWARE_ONLY) == 0;
503    } else {
504        return (mDevice->flags & KEYMASTER_SOFTWARE_ONLY) == 0 &&
505               (mDevice->common.module->module_api_version >= KEYMASTER_MODULE_API_VERSION_0_2);
506    }
507}
508
509ResponseCode KeyStore::getKeyForName(Blob* keyBlob, const android::String8& keyName,
510                                     const uid_t uid, const BlobType type) {
511    android::String8 filepath8(getKeyNameForUidWithDir(keyName, uid, type));
512    uid_t userId = get_user_id(uid);
513
514    ResponseCode responseCode = get(filepath8.string(), keyBlob, type, userId);
515    if (responseCode == NO_ERROR) {
516        return responseCode;
517    }
518
519    // If this is one of the legacy UID->UID mappings, use it.
520    uid_t euid = get_keystore_euid(uid);
521    if (euid != uid) {
522        filepath8 = getKeyNameForUidWithDir(keyName, euid, type);
523        responseCode = get(filepath8.string(), keyBlob, type, userId);
524        if (responseCode == NO_ERROR) {
525            return responseCode;
526        }
527    }
528
529    // They might be using a granted key.
530    android::String8 filename8 = getKeyName(keyName, type);
531    char* end;
532    strtoul(filename8.string(), &end, 10);
533    if (end[0] != '_' || end[1] == 0) {
534        return KEY_NOT_FOUND;
535    }
536    filepath8 = android::String8::format("%s/%s", getUserState(userId)->getUserDirName(),
537                                         filename8.string());
538    if (!hasGrant(filepath8.string(), uid)) {
539        return responseCode;
540    }
541
542    // It is a granted key. Try to load it.
543    return get(filepath8.string(), keyBlob, type, userId);
544}
545
546UserState* KeyStore::getUserState(uid_t userId) {
547    for (android::Vector<UserState*>::iterator it(mMasterKeys.begin()); it != mMasterKeys.end();
548         it++) {
549        UserState* state = *it;
550        if (state->getUserId() == userId) {
551            return state;
552        }
553    }
554
555    UserState* userState = new UserState(userId);
556    if (!userState->initialize()) {
557        /* There's not much we can do if initialization fails. Trying to
558         * unlock the keystore for that user will fail as well, so any
559         * subsequent request for this user will just return SYSTEM_ERROR.
560         */
561        ALOGE("User initialization failed for %u; subsuquent operations will fail", userId);
562    }
563    mMasterKeys.add(userState);
564    return userState;
565}
566
567UserState* KeyStore::getUserStateByUid(uid_t uid) {
568    uid_t userId = get_user_id(uid);
569    return getUserState(userId);
570}
571
572const UserState* KeyStore::getUserState(uid_t userId) const {
573    for (android::Vector<UserState*>::const_iterator it(mMasterKeys.begin());
574         it != mMasterKeys.end(); it++) {
575        UserState* state = *it;
576        if (state->getUserId() == userId) {
577            return state;
578        }
579    }
580
581    return NULL;
582}
583
584const UserState* KeyStore::getUserStateByUid(uid_t uid) const {
585    uid_t userId = get_user_id(uid);
586    return getUserState(userId);
587}
588
589const grant_t* KeyStore::getGrant(const char* filename, uid_t uid) const {
590    for (android::Vector<grant_t*>::const_iterator it(mGrants.begin()); it != mGrants.end(); it++) {
591        grant_t* grant = *it;
592        if (grant->uid == uid &&
593            !strcmp(reinterpret_cast<const char*>(grant->filename), filename)) {
594            return grant;
595        }
596    }
597    return NULL;
598}
599
600bool KeyStore::upgradeBlob(const char* filename, Blob* blob, const uint8_t oldVersion,
601                           const BlobType type, uid_t uid) {
602    bool updated = false;
603    uint8_t version = oldVersion;
604
605    /* From V0 -> V1: All old types were unknown */
606    if (version == 0) {
607        ALOGV("upgrading to version 1 and setting type %d", type);
608
609        blob->setType(type);
610        if (type == TYPE_KEY_PAIR) {
611            importBlobAsKey(blob, filename, uid);
612        }
613        version = 1;
614        updated = true;
615    }
616
617    /* From V1 -> V2: All old keys were encrypted */
618    if (version == 1) {
619        ALOGV("upgrading to version 2");
620
621        blob->setEncrypted(true);
622        version = 2;
623        updated = true;
624    }
625
626    /*
627     * If we've updated, set the key blob to the right version
628     * and write it.
629     */
630    if (updated) {
631        ALOGV("updated and writing file %s", filename);
632        blob->setVersion(version);
633    }
634
635    return updated;
636}
637
638struct BIO_Delete {
639    void operator()(BIO* p) const { BIO_free(p); }
640};
641typedef UniquePtr<BIO, BIO_Delete> Unique_BIO;
642
643ResponseCode KeyStore::importBlobAsKey(Blob* blob, const char* filename, uid_t uid) {
644    // We won't even write to the blob directly with this BIO, so const_cast is okay.
645    Unique_BIO b(BIO_new_mem_buf(const_cast<uint8_t*>(blob->getValue()), blob->getLength()));
646    if (b.get() == NULL) {
647        ALOGE("Problem instantiating BIO");
648        return SYSTEM_ERROR;
649    }
650
651    Unique_EVP_PKEY pkey(PEM_read_bio_PrivateKey(b.get(), NULL, NULL, NULL));
652    if (pkey.get() == NULL) {
653        ALOGE("Couldn't read old PEM file");
654        return SYSTEM_ERROR;
655    }
656
657    Unique_PKCS8_PRIV_KEY_INFO pkcs8(EVP_PKEY2PKCS8(pkey.get()));
658    int len = i2d_PKCS8_PRIV_KEY_INFO(pkcs8.get(), NULL);
659    if (len < 0) {
660        ALOGE("Couldn't measure PKCS#8 length");
661        return SYSTEM_ERROR;
662    }
663
664    UniquePtr<unsigned char[]> pkcs8key(new unsigned char[len]);
665    uint8_t* tmp = pkcs8key.get();
666    if (i2d_PKCS8_PRIV_KEY_INFO(pkcs8.get(), &tmp) != len) {
667        ALOGE("Couldn't convert to PKCS#8");
668        return SYSTEM_ERROR;
669    }
670
671    ResponseCode rc = importKey(pkcs8key.get(), len, filename, get_user_id(uid),
672                                blob->isEncrypted() ? KEYSTORE_FLAG_ENCRYPTED : KEYSTORE_FLAG_NONE);
673    if (rc != NO_ERROR) {
674        return rc;
675    }
676
677    return get(filename, blob, TYPE_KEY_PAIR, uid);
678}
679
680void KeyStore::readMetaData() {
681    int in = TEMP_FAILURE_RETRY(open(sMetaDataFile, O_RDONLY));
682    if (in < 0) {
683        return;
684    }
685    size_t fileLength = readFully(in, (uint8_t*)&mMetaData, sizeof(mMetaData));
686    if (fileLength != sizeof(mMetaData)) {
687        ALOGI("Metadata file is %zd bytes (%zd experted); upgrade?", fileLength, sizeof(mMetaData));
688    }
689    close(in);
690}
691
692void KeyStore::writeMetaData() {
693    const char* tmpFileName = ".metadata.tmp";
694    int out =
695        TEMP_FAILURE_RETRY(open(tmpFileName, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR));
696    if (out < 0) {
697        ALOGE("couldn't write metadata file: %s", strerror(errno));
698        return;
699    }
700    size_t fileLength = writeFully(out, (uint8_t*)&mMetaData, sizeof(mMetaData));
701    if (fileLength != sizeof(mMetaData)) {
702        ALOGI("Could only write %zd bytes to metadata file (%zd expected)", fileLength,
703              sizeof(mMetaData));
704    }
705    close(out);
706    rename(tmpFileName, sMetaDataFile);
707}
708
709bool KeyStore::upgradeKeystore() {
710    bool upgraded = false;
711
712    if (mMetaData.version == 0) {
713        UserState* userState = getUserStateByUid(0);
714
715        // Initialize first so the directory is made.
716        userState->initialize();
717
718        // Migrate the old .masterkey file to user 0.
719        if (access(sOldMasterKey, R_OK) == 0) {
720            if (rename(sOldMasterKey, userState->getMasterKeyFileName()) < 0) {
721                ALOGE("couldn't migrate old masterkey: %s", strerror(errno));
722                return false;
723            }
724        }
725
726        // Initialize again in case we had a key.
727        userState->initialize();
728
729        // Try to migrate existing keys.
730        DIR* dir = opendir(".");
731        if (!dir) {
732            // Give up now; maybe we can upgrade later.
733            ALOGE("couldn't open keystore's directory; something is wrong");
734            return false;
735        }
736
737        struct dirent* file;
738        while ((file = readdir(dir)) != NULL) {
739            // We only care about files.
740            if (file->d_type != DT_REG) {
741                continue;
742            }
743
744            // Skip anything that starts with a "."
745            if (file->d_name[0] == '.') {
746                continue;
747            }
748
749            // Find the current file's user.
750            char* end;
751            unsigned long thisUid = strtoul(file->d_name, &end, 10);
752            if (end[0] != '_' || end[1] == 0) {
753                continue;
754            }
755            UserState* otherUser = getUserStateByUid(thisUid);
756            if (otherUser->getUserId() != 0) {
757                unlinkat(dirfd(dir), file->d_name, 0);
758            }
759
760            // Rename the file into user directory.
761            DIR* otherdir = opendir(otherUser->getUserDirName());
762            if (otherdir == NULL) {
763                ALOGW("couldn't open user directory for rename");
764                continue;
765            }
766            if (renameat(dirfd(dir), file->d_name, dirfd(otherdir), file->d_name) < 0) {
767                ALOGW("couldn't rename blob: %s: %s", file->d_name, strerror(errno));
768            }
769            closedir(otherdir);
770        }
771        closedir(dir);
772
773        mMetaData.version = 1;
774        upgraded = true;
775    }
776
777    return upgraded;
778}
779