Move keystore from frameworks/base
Move keystore from frameworks/base at commit
57ff581bd9b16a192a567f84d0e0a5c82d866343
Change-Id: I1e62488d63810f14e40ffb3d192925ff4eeb8906
diff --git a/keystore/keystore.cpp b/keystore/keystore.cpp
new file mode 100644
index 0000000..2c9cb35
--- /dev/null
+++ b/keystore/keystore.cpp
@@ -0,0 +1,810 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <arpa/inet.h>
+
+#include <openssl/aes.h>
+#include <openssl/evp.h>
+#include <openssl/md5.h>
+
+#define LOG_TAG "keystore"
+#include <cutils/log.h>
+#include <cutils/sockets.h>
+#include <private/android_filesystem_config.h>
+
+#include "keystore.h"
+
+/* KeyStore is a secured storage for key-value pairs. In this implementation,
+ * each file stores one key-value pair. Keys are encoded in file names, and
+ * values are encrypted with checksums. The encryption key is protected by a
+ * user-defined password. To keep things simple, buffers are always larger than
+ * the maximum space we needed, so boundary checks on buffers are omitted. */
+
+#define KEY_SIZE ((NAME_MAX - 15) / 2)
+#define VALUE_SIZE 32768
+#define PASSWORD_SIZE VALUE_SIZE
+
+struct Value {
+ int length;
+ uint8_t value[VALUE_SIZE];
+};
+
+/* Here is the encoding of keys. This is necessary in order to allow arbitrary
+ * characters in keys. Characters in [0-~] are not encoded. Others are encoded
+ * into two bytes. The first byte is one of [+-.] which represents the first
+ * two bits of the character. The second byte encodes the rest of the bits into
+ * [0-o]. Therefore in the worst case the length of a key gets doubled. Note
+ * that Base64 cannot be used here due to the need of prefix match on keys. */
+
+static int encode_key(char* out, uid_t uid, const Value* key) {
+ int n = snprintf(out, NAME_MAX, "%u_", uid);
+ out += n;
+ const uint8_t* in = key->value;
+ int length = key->length;
+ for (int i = length; i > 0; --i, ++in, ++out) {
+ if (*in >= '0' && *in <= '~') {
+ *out = *in;
+ } else {
+ *out = '+' + (*in >> 6);
+ *++out = '0' + (*in & 0x3F);
+ ++length;
+ }
+ }
+ *out = '\0';
+ return n + length;
+}
+
+static int decode_key(uint8_t* out, char* in, int length) {
+ for (int i = 0; i < length; ++i, ++in, ++out) {
+ if (*in >= '0' && *in <= '~') {
+ *out = *in;
+ } else {
+ *out = (*in - '+') << 6;
+ *out |= (*++in - '0') & 0x3F;
+ --length;
+ }
+ }
+ *out = '\0';
+ return length;
+}
+
+static size_t readFully(int fd, uint8_t* data, size_t size) {
+ size_t remaining = size;
+ while (remaining > 0) {
+ ssize_t n = TEMP_FAILURE_RETRY(read(fd, data, size));
+ if (n == -1 || n == 0) {
+ return size-remaining;
+ }
+ data += n;
+ remaining -= n;
+ }
+ return size;
+}
+
+static size_t writeFully(int fd, uint8_t* data, size_t size) {
+ size_t remaining = size;
+ while (remaining > 0) {
+ ssize_t n = TEMP_FAILURE_RETRY(write(fd, data, size));
+ if (n == -1 || n == 0) {
+ return size-remaining;
+ }
+ data += n;
+ remaining -= n;
+ }
+ return size;
+}
+
+class Entropy {
+public:
+ Entropy() : mRandom(-1) {}
+ ~Entropy() {
+ if (mRandom != -1) {
+ close(mRandom);
+ }
+ }
+
+ bool open() {
+ const char* randomDevice = "/dev/urandom";
+ mRandom = ::open(randomDevice, O_RDONLY);
+ if (mRandom == -1) {
+ ALOGE("open: %s: %s", randomDevice, strerror(errno));
+ return false;
+ }
+ return true;
+ }
+
+ bool generate_random_data(uint8_t* data, size_t size) {
+ return (readFully(mRandom, data, size) == size);
+ }
+
+private:
+ int mRandom;
+};
+
+/* Here is the file format. There are two parts in blob.value, the secret and
+ * the description. The secret is stored in ciphertext, and its original size
+ * can be found in blob.length. The description is stored after the secret in
+ * plaintext, and its size is specified in blob.info. The total size of the two
+ * parts must be no more than VALUE_SIZE bytes. The first three bytes of the
+ * file are reserved for future use and are always set to zero. Fields other
+ * than blob.info, blob.length, and blob.value are modified by encryptBlob()
+ * and decryptBlob(). Thus they should not be accessed from outside. */
+
+struct __attribute__((packed)) blob {
+ uint8_t reserved[3];
+ uint8_t info;
+ uint8_t vector[AES_BLOCK_SIZE];
+ uint8_t encrypted[0];
+ uint8_t digest[MD5_DIGEST_LENGTH];
+ uint8_t digested[0];
+ int32_t length; // in network byte order when encrypted
+ uint8_t value[VALUE_SIZE + AES_BLOCK_SIZE];
+};
+
+class Blob {
+public:
+ Blob(uint8_t* value, int32_t valueLength, uint8_t* info, uint8_t infoLength) {
+ mBlob.length = valueLength;
+ memcpy(mBlob.value, value, valueLength);
+
+ mBlob.info = infoLength;
+ memcpy(mBlob.value + valueLength, info, infoLength);
+ }
+
+ Blob(blob b) {
+ mBlob = b;
+ }
+
+ Blob() {}
+
+ uint8_t* getValue() {
+ return mBlob.value;
+ }
+
+ int32_t getLength() {
+ return mBlob.length;
+ }
+
+ uint8_t getInfo() {
+ return mBlob.info;
+ }
+
+ ResponseCode encryptBlob(const char* filename, AES_KEY *aes_key, Entropy* entropy) {
+ if (!entropy->generate_random_data(mBlob.vector, AES_BLOCK_SIZE)) {
+ return SYSTEM_ERROR;
+ }
+
+ // data includes the value and the value's length
+ size_t dataLength = mBlob.length + sizeof(mBlob.length);
+ // pad data to the AES_BLOCK_SIZE
+ size_t digestedLength = ((dataLength + AES_BLOCK_SIZE - 1)
+ / AES_BLOCK_SIZE * AES_BLOCK_SIZE);
+ // encrypted data includes the digest value
+ size_t encryptedLength = digestedLength + MD5_DIGEST_LENGTH;
+ // move info after space for padding
+ memmove(&mBlob.encrypted[encryptedLength], &mBlob.value[mBlob.length], mBlob.info);
+ // zero padding area
+ memset(mBlob.value + mBlob.length, 0, digestedLength - dataLength);
+
+ mBlob.length = htonl(mBlob.length);
+ MD5(mBlob.digested, digestedLength, mBlob.digest);
+
+ uint8_t vector[AES_BLOCK_SIZE];
+ memcpy(vector, mBlob.vector, AES_BLOCK_SIZE);
+ AES_cbc_encrypt(mBlob.encrypted, mBlob.encrypted, encryptedLength,
+ aes_key, vector, AES_ENCRYPT);
+
+ memset(mBlob.reserved, 0, sizeof(mBlob.reserved));
+ size_t headerLength = (mBlob.encrypted - (uint8_t*) &mBlob);
+ size_t fileLength = encryptedLength + headerLength + mBlob.info;
+
+ const char* tmpFileName = ".tmp";
+ int out = open(tmpFileName, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR);
+ if (out == -1) {
+ return SYSTEM_ERROR;
+ }
+ size_t writtenBytes = writeFully(out, (uint8_t*) &mBlob, fileLength);
+ if (close(out) != 0) {
+ return SYSTEM_ERROR;
+ }
+ if (writtenBytes != fileLength) {
+ unlink(tmpFileName);
+ return SYSTEM_ERROR;
+ }
+ return (rename(tmpFileName, filename) == 0) ? NO_ERROR : SYSTEM_ERROR;
+ }
+
+ ResponseCode decryptBlob(const char* filename, AES_KEY *aes_key) {
+ int in = open(filename, O_RDONLY);
+ if (in == -1) {
+ return (errno == ENOENT) ? KEY_NOT_FOUND : SYSTEM_ERROR;
+ }
+ // fileLength may be less than sizeof(mBlob) since the in
+ // memory version has extra padding to tolerate rounding up to
+ // the AES_BLOCK_SIZE
+ size_t fileLength = readFully(in, (uint8_t*) &mBlob, sizeof(mBlob));
+ if (close(in) != 0) {
+ return SYSTEM_ERROR;
+ }
+ size_t headerLength = (mBlob.encrypted - (uint8_t*) &mBlob);
+ if (fileLength < headerLength) {
+ return VALUE_CORRUPTED;
+ }
+
+ ssize_t encryptedLength = fileLength - (headerLength + mBlob.info);
+ if (encryptedLength < 0 || encryptedLength % AES_BLOCK_SIZE != 0) {
+ return VALUE_CORRUPTED;
+ }
+ AES_cbc_encrypt(mBlob.encrypted, mBlob.encrypted, encryptedLength, aes_key,
+ mBlob.vector, AES_DECRYPT);
+ size_t digestedLength = encryptedLength - MD5_DIGEST_LENGTH;
+ uint8_t computedDigest[MD5_DIGEST_LENGTH];
+ MD5(mBlob.digested, digestedLength, computedDigest);
+ if (memcmp(mBlob.digest, computedDigest, MD5_DIGEST_LENGTH) != 0) {
+ return VALUE_CORRUPTED;
+ }
+
+ ssize_t maxValueLength = digestedLength - sizeof(mBlob.length);
+ mBlob.length = ntohl(mBlob.length);
+ if (mBlob.length < 0 || mBlob.length > maxValueLength) {
+ return VALUE_CORRUPTED;
+ }
+ if (mBlob.info != 0) {
+ // move info from after padding to after data
+ memmove(&mBlob.value[mBlob.length], &mBlob.value[maxValueLength], mBlob.info);
+ }
+ return NO_ERROR;
+ }
+
+private:
+ struct blob mBlob;
+};
+
+class KeyStore {
+public:
+ KeyStore(Entropy* entropy) : mEntropy(entropy), mRetry(MAX_RETRY) {
+ if (access(MASTER_KEY_FILE, R_OK) == 0) {
+ setState(STATE_LOCKED);
+ } else {
+ setState(STATE_UNINITIALIZED);
+ }
+ }
+
+ State getState() {
+ return mState;
+ }
+
+ int8_t getRetry() {
+ return mRetry;
+ }
+
+ ResponseCode initialize(Value* pw) {
+ if (!generateMasterKey()) {
+ return SYSTEM_ERROR;
+ }
+ ResponseCode response = writeMasterKey(pw);
+ if (response != NO_ERROR) {
+ return response;
+ }
+ setupMasterKeys();
+ return NO_ERROR;
+ }
+
+ ResponseCode writeMasterKey(Value* pw) {
+ uint8_t passwordKey[MASTER_KEY_SIZE_BYTES];
+ generateKeyFromPassword(passwordKey, MASTER_KEY_SIZE_BYTES, pw, mSalt);
+ AES_KEY passwordAesKey;
+ AES_set_encrypt_key(passwordKey, MASTER_KEY_SIZE_BITS, &passwordAesKey);
+ Blob masterKeyBlob(mMasterKey, sizeof(mMasterKey), mSalt, sizeof(mSalt));
+ return masterKeyBlob.encryptBlob(MASTER_KEY_FILE, &passwordAesKey, mEntropy);
+ }
+
+ ResponseCode readMasterKey(Value* pw) {
+ int in = open(MASTER_KEY_FILE, O_RDONLY);
+ if (in == -1) {
+ return SYSTEM_ERROR;
+ }
+
+ // we read the raw blob to just to get the salt to generate
+ // the AES key, then we create the Blob to use with decryptBlob
+ blob rawBlob;
+ size_t length = readFully(in, (uint8_t*) &rawBlob, sizeof(rawBlob));
+ if (close(in) != 0) {
+ return SYSTEM_ERROR;
+ }
+ // find salt at EOF if present, otherwise we have an old file
+ uint8_t* salt;
+ if (length > SALT_SIZE && rawBlob.info == SALT_SIZE) {
+ salt = (uint8_t*) &rawBlob + length - SALT_SIZE;
+ } else {
+ salt = NULL;
+ }
+ uint8_t passwordKey[MASTER_KEY_SIZE_BYTES];
+ generateKeyFromPassword(passwordKey, MASTER_KEY_SIZE_BYTES, pw, salt);
+ AES_KEY passwordAesKey;
+ AES_set_decrypt_key(passwordKey, MASTER_KEY_SIZE_BITS, &passwordAesKey);
+ Blob masterKeyBlob(rawBlob);
+ ResponseCode response = masterKeyBlob.decryptBlob(MASTER_KEY_FILE, &passwordAesKey);
+ if (response == SYSTEM_ERROR) {
+ return SYSTEM_ERROR;
+ }
+ if (response == NO_ERROR && masterKeyBlob.getLength() == MASTER_KEY_SIZE_BYTES) {
+ // if salt was missing, generate one and write a new master key file with the salt.
+ if (salt == NULL) {
+ if (!generateSalt()) {
+ return SYSTEM_ERROR;
+ }
+ response = writeMasterKey(pw);
+ }
+ if (response == NO_ERROR) {
+ memcpy(mMasterKey, masterKeyBlob.getValue(), MASTER_KEY_SIZE_BYTES);
+ setupMasterKeys();
+ }
+ return response;
+ }
+ if (mRetry <= 0) {
+ reset();
+ return UNINITIALIZED;
+ }
+ --mRetry;
+ switch (mRetry) {
+ case 0: return WRONG_PASSWORD_0;
+ case 1: return WRONG_PASSWORD_1;
+ case 2: return WRONG_PASSWORD_2;
+ case 3: return WRONG_PASSWORD_3;
+ default: return WRONG_PASSWORD_3;
+ }
+ }
+
+ bool reset() {
+ clearMasterKeys();
+ setState(STATE_UNINITIALIZED);
+
+ DIR* dir = opendir(".");
+ struct dirent* file;
+
+ if (!dir) {
+ return false;
+ }
+ while ((file = readdir(dir)) != NULL) {
+ unlink(file->d_name);
+ }
+ closedir(dir);
+ return true;
+ }
+
+ bool isEmpty() {
+ DIR* dir = opendir(".");
+ struct dirent* file;
+ if (!dir) {
+ return true;
+ }
+ bool result = true;
+ while ((file = readdir(dir)) != NULL) {
+ if (isKeyFile(file->d_name)) {
+ result = false;
+ break;
+ }
+ }
+ closedir(dir);
+ return result;
+ }
+
+ void lock() {
+ clearMasterKeys();
+ setState(STATE_LOCKED);
+ }
+
+ ResponseCode get(const char* filename, Blob* keyBlob) {
+ return keyBlob->decryptBlob(filename, &mMasterKeyDecryption);
+ }
+
+ ResponseCode put(const char* filename, Blob* keyBlob) {
+ return keyBlob->encryptBlob(filename, &mMasterKeyEncryption, mEntropy);
+ }
+
+private:
+ static const char* MASTER_KEY_FILE;
+ static const int MASTER_KEY_SIZE_BYTES = 16;
+ static const int MASTER_KEY_SIZE_BITS = MASTER_KEY_SIZE_BYTES * 8;
+
+ static const int MAX_RETRY = 4;
+ static const size_t SALT_SIZE = 16;
+
+ Entropy* mEntropy;
+
+ State mState;
+ int8_t mRetry;
+
+ uint8_t mMasterKey[MASTER_KEY_SIZE_BYTES];
+ uint8_t mSalt[SALT_SIZE];
+
+ AES_KEY mMasterKeyEncryption;
+ AES_KEY mMasterKeyDecryption;
+
+ void setState(State state) {
+ mState = state;
+ if (mState == STATE_NO_ERROR || mState == STATE_UNINITIALIZED) {
+ mRetry = MAX_RETRY;
+ }
+ }
+
+ bool generateSalt() {
+ return mEntropy->generate_random_data(mSalt, sizeof(mSalt));
+ }
+
+ bool generateMasterKey() {
+ if (!mEntropy->generate_random_data(mMasterKey, sizeof(mMasterKey))) {
+ return false;
+ }
+ if (!generateSalt()) {
+ return false;
+ }
+ return true;
+ }
+
+ void setupMasterKeys() {
+ AES_set_encrypt_key(mMasterKey, MASTER_KEY_SIZE_BITS, &mMasterKeyEncryption);
+ AES_set_decrypt_key(mMasterKey, MASTER_KEY_SIZE_BITS, &mMasterKeyDecryption);
+ setState(STATE_NO_ERROR);
+ }
+
+ void clearMasterKeys() {
+ memset(mMasterKey, 0, sizeof(mMasterKey));
+ memset(mSalt, 0, sizeof(mSalt));
+ memset(&mMasterKeyEncryption, 0, sizeof(mMasterKeyEncryption));
+ memset(&mMasterKeyDecryption, 0, sizeof(mMasterKeyDecryption));
+ }
+
+ static void generateKeyFromPassword(uint8_t* key, ssize_t keySize, Value* pw, uint8_t* salt) {
+ size_t saltSize;
+ if (salt != NULL) {
+ saltSize = SALT_SIZE;
+ } else {
+ // pre-gingerbread used this hardwired salt, readMasterKey will rewrite these when found
+ salt = (uint8_t*) "keystore";
+ // sizeof = 9, not strlen = 8
+ saltSize = sizeof("keystore");
+ }
+ PKCS5_PBKDF2_HMAC_SHA1((char*) pw->value, pw->length, salt, saltSize, 8192, keySize, key);
+ }
+
+ static bool isKeyFile(const char* filename) {
+ return ((strcmp(filename, MASTER_KEY_FILE) != 0)
+ && (strcmp(filename, ".") != 0)
+ && (strcmp(filename, "..") != 0));
+ }
+};
+
+const char* KeyStore::MASTER_KEY_FILE = ".masterkey";
+
+/* Here is the protocol used in both requests and responses:
+ * code [length_1 message_1 ... length_n message_n] end-of-file
+ * where code is one byte long and lengths are unsigned 16-bit integers in
+ * network order. Thus the maximum length of a message is 65535 bytes. */
+
+static int recv_code(int sock, int8_t* code) {
+ return recv(sock, code, 1, 0) == 1;
+}
+
+static int recv_message(int sock, uint8_t* message, int length) {
+ uint8_t bytes[2];
+ if (recv(sock, &bytes[0], 1, 0) != 1 ||
+ recv(sock, &bytes[1], 1, 0) != 1) {
+ return -1;
+ } else {
+ int offset = bytes[0] << 8 | bytes[1];
+ if (length < offset) {
+ return -1;
+ }
+ length = offset;
+ offset = 0;
+ while (offset < length) {
+ int n = recv(sock, &message[offset], length - offset, 0);
+ if (n <= 0) {
+ return -1;
+ }
+ offset += n;
+ }
+ }
+ return length;
+}
+
+static int recv_end_of_file(int sock) {
+ uint8_t byte;
+ return recv(sock, &byte, 1, 0) == 0;
+}
+
+static void send_code(int sock, int8_t code) {
+ send(sock, &code, 1, 0);
+}
+
+static void send_message(int sock, uint8_t* message, int length) {
+ uint16_t bytes = htons(length);
+ send(sock, &bytes, 2, 0);
+ send(sock, message, length, 0);
+}
+
+/* Here are the actions. Each of them is a function without arguments. All
+ * information is defined in global variables, which are set properly before
+ * performing an action. The number of parameters required by each action is
+ * fixed and defined in a table. If the return value of an action is positive,
+ * it will be treated as a response code and transmitted to the client. Note
+ * that the lengths of parameters are checked when they are received, so
+ * boundary checks on parameters are omitted. */
+
+static const ResponseCode NO_ERROR_RESPONSE_CODE_SENT = (ResponseCode) 0;
+
+static ResponseCode test(KeyStore* keyStore, int sock, uid_t uid, Value*, Value*) {
+ return (ResponseCode) keyStore->getState();
+}
+
+static ResponseCode get(KeyStore* keyStore, int sock, uid_t uid, Value* keyName, Value*) {
+ char filename[NAME_MAX];
+ encode_key(filename, uid, keyName);
+ Blob keyBlob;
+ ResponseCode responseCode = keyStore->get(filename, &keyBlob);
+ if (responseCode != NO_ERROR) {
+ return responseCode;
+ }
+ send_code(sock, NO_ERROR);
+ send_message(sock, keyBlob.getValue(), keyBlob.getLength());
+ return NO_ERROR_RESPONSE_CODE_SENT;
+}
+
+static ResponseCode insert(KeyStore* keyStore, int sock, uid_t uid, Value* keyName, Value* val) {
+ char filename[NAME_MAX];
+ encode_key(filename, uid, keyName);
+ Blob keyBlob(val->value, val->length, NULL, 0);
+ return keyStore->put(filename, &keyBlob);
+}
+
+static ResponseCode del(KeyStore* keyStore, int sock, uid_t uid, Value* keyName, Value*) {
+ char filename[NAME_MAX];
+ encode_key(filename, uid, keyName);
+ return (unlink(filename) && errno != ENOENT) ? SYSTEM_ERROR : NO_ERROR;
+}
+
+static ResponseCode exist(KeyStore* keyStore, int sock, uid_t uid, Value* keyName, Value*) {
+ char filename[NAME_MAX];
+ encode_key(filename, uid, keyName);
+ if (access(filename, R_OK) == -1) {
+ return (errno != ENOENT) ? SYSTEM_ERROR : KEY_NOT_FOUND;
+ }
+ return NO_ERROR;
+}
+
+static ResponseCode saw(KeyStore* keyStore, int sock, uid_t uid, Value* keyPrefix, Value*) {
+ DIR* dir = opendir(".");
+ if (!dir) {
+ return SYSTEM_ERROR;
+ }
+ char filename[NAME_MAX];
+ int n = encode_key(filename, uid, keyPrefix);
+ send_code(sock, NO_ERROR);
+
+ struct dirent* file;
+ while ((file = readdir(dir)) != NULL) {
+ if (!strncmp(filename, file->d_name, n)) {
+ char* p = &file->d_name[n];
+ keyPrefix->length = decode_key(keyPrefix->value, p, strlen(p));
+ send_message(sock, keyPrefix->value, keyPrefix->length);
+ }
+ }
+ closedir(dir);
+ return NO_ERROR_RESPONSE_CODE_SENT;
+}
+
+static ResponseCode reset(KeyStore* keyStore, int sock, uid_t uid, Value*, Value*) {
+ return keyStore->reset() ? NO_ERROR : SYSTEM_ERROR;
+}
+
+/* Here is the history. To improve the security, the parameters to generate the
+ * master key has been changed. To make a seamless transition, we update the
+ * file using the same password when the user unlock it for the first time. If
+ * any thing goes wrong during the transition, the new file will not overwrite
+ * the old one. This avoids permanent damages of the existing data. */
+
+static ResponseCode password(KeyStore* keyStore, int sock, uid_t uid, Value* pw, Value*) {
+ switch (keyStore->getState()) {
+ case STATE_UNINITIALIZED: {
+ // generate master key, encrypt with password, write to file, initialize mMasterKey*.
+ return keyStore->initialize(pw);
+ }
+ case STATE_NO_ERROR: {
+ // rewrite master key with new password.
+ return keyStore->writeMasterKey(pw);
+ }
+ case STATE_LOCKED: {
+ // read master key, decrypt with password, initialize mMasterKey*.
+ return keyStore->readMasterKey(pw);
+ }
+ }
+ return SYSTEM_ERROR;
+}
+
+static ResponseCode lock(KeyStore* keyStore, int sock, uid_t uid, Value*, Value*) {
+ keyStore->lock();
+ return NO_ERROR;
+}
+
+static ResponseCode unlock(KeyStore* keyStore, int sock, uid_t uid, Value* pw, Value* unused) {
+ return password(keyStore, sock, uid, pw, unused);
+}
+
+static ResponseCode zero(KeyStore* keyStore, int sock, uid_t uid, Value*, Value*) {
+ return keyStore->isEmpty() ? KEY_NOT_FOUND : NO_ERROR;
+}
+
+/* Here are the permissions, actions, users, and the main function. */
+
+enum perm {
+ TEST = 1,
+ GET = 2,
+ INSERT = 4,
+ DELETE = 8,
+ EXIST = 16,
+ SAW = 32,
+ RESET = 64,
+ PASSWORD = 128,
+ LOCK = 256,
+ UNLOCK = 512,
+ ZERO = 1024,
+};
+
+static const int MAX_PARAM = 2;
+
+static const State STATE_ANY = (State) 0;
+
+static struct action {
+ ResponseCode (*run)(KeyStore* keyStore, int sock, uid_t uid, Value* param1, Value* param2);
+ int8_t code;
+ State state;
+ uint32_t perm;
+ int lengths[MAX_PARAM];
+} actions[] = {
+ {test, 't', STATE_ANY, TEST, {0, 0}},
+ {get, 'g', STATE_NO_ERROR, GET, {KEY_SIZE, 0}},
+ {insert, 'i', STATE_NO_ERROR, INSERT, {KEY_SIZE, VALUE_SIZE}},
+ {del, 'd', STATE_ANY, DELETE, {KEY_SIZE, 0}},
+ {exist, 'e', STATE_ANY, EXIST, {KEY_SIZE, 0}},
+ {saw, 's', STATE_ANY, SAW, {KEY_SIZE, 0}},
+ {reset, 'r', STATE_ANY, RESET, {0, 0}},
+ {password, 'p', STATE_ANY, PASSWORD, {PASSWORD_SIZE, 0}},
+ {lock, 'l', STATE_NO_ERROR, LOCK, {0, 0}},
+ {unlock, 'u', STATE_LOCKED, UNLOCK, {PASSWORD_SIZE, 0}},
+ {zero, 'z', STATE_ANY, ZERO, {0, 0}},
+ {NULL, 0 , STATE_ANY, 0, {0, 0}},
+};
+
+static struct user {
+ uid_t uid;
+ uid_t euid;
+ uint32_t perms;
+} users[] = {
+ {AID_SYSTEM, ~0, ~0},
+ {AID_VPN, AID_SYSTEM, GET},
+ {AID_WIFI, AID_SYSTEM, GET},
+ {AID_ROOT, AID_SYSTEM, GET},
+ {~0, ~0, TEST | GET | INSERT | DELETE | EXIST | SAW},
+};
+
+static ResponseCode process(KeyStore* keyStore, int sock, uid_t uid, int8_t code) {
+ struct user* user = users;
+ struct action* action = actions;
+ int i;
+
+ while (~user->uid && user->uid != uid) {
+ ++user;
+ }
+ while (action->code && action->code != code) {
+ ++action;
+ }
+ if (!action->code) {
+ return UNDEFINED_ACTION;
+ }
+ if (!(action->perm & user->perms)) {
+ return PERMISSION_DENIED;
+ }
+ if (action->state != STATE_ANY && action->state != keyStore->getState()) {
+ return (ResponseCode) keyStore->getState();
+ }
+ if (~user->euid) {
+ uid = user->euid;
+ }
+ Value params[MAX_PARAM];
+ for (i = 0; i < MAX_PARAM && action->lengths[i] != 0; ++i) {
+ params[i].length = recv_message(sock, params[i].value, action->lengths[i]);
+ if (params[i].length < 0) {
+ return PROTOCOL_ERROR;
+ }
+ }
+ if (!recv_end_of_file(sock)) {
+ return PROTOCOL_ERROR;
+ }
+ return action->run(keyStore, sock, uid, ¶ms[0], ¶ms[1]);
+}
+
+int main(int argc, char* argv[]) {
+ int controlSocket = android_get_control_socket("keystore");
+ if (argc < 2) {
+ ALOGE("A directory must be specified!");
+ return 1;
+ }
+ if (chdir(argv[1]) == -1) {
+ ALOGE("chdir: %s: %s", argv[1], strerror(errno));
+ return 1;
+ }
+
+ Entropy entropy;
+ if (!entropy.open()) {
+ return 1;
+ }
+ if (listen(controlSocket, 3) == -1) {
+ ALOGE("listen: %s", strerror(errno));
+ return 1;
+ }
+
+ signal(SIGPIPE, SIG_IGN);
+
+ KeyStore keyStore(&entropy);
+ int sock;
+ while ((sock = accept(controlSocket, NULL, 0)) != -1) {
+ struct timeval tv;
+ tv.tv_sec = 3;
+ setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
+ setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
+
+ struct ucred cred;
+ socklen_t size = sizeof(cred);
+ int credResult = getsockopt(sock, SOL_SOCKET, SO_PEERCRED, &cred, &size);
+ if (credResult != 0) {
+ ALOGW("getsockopt: %s", strerror(errno));
+ } else {
+ int8_t request;
+ if (recv_code(sock, &request)) {
+ State old_state = keyStore.getState();
+ ResponseCode response = process(&keyStore, sock, cred.uid, request);
+ if (response == NO_ERROR_RESPONSE_CODE_SENT) {
+ response = NO_ERROR;
+ } else {
+ send_code(sock, response);
+ }
+ ALOGI("uid: %d action: %c -> %d state: %d -> %d retry: %d",
+ cred.uid,
+ request, response,
+ old_state, keyStore.getState(),
+ keyStore.getRetry());
+ }
+ }
+ close(sock);
+ }
+ ALOGE("accept: %s", strerror(errno));
+ return 1;
+}