diff --git a/keystore/Android.bp b/keystore/Android.bp
index 8af8717..9ce00c2 100644
--- a/keystore/Android.bp
+++ b/keystore/Android.bp
@@ -25,7 +25,6 @@
         "auth_token_table.cpp",
         "blob.cpp",
         "confirmation_manager.cpp",
-        "entropy.cpp",
         "grant_store.cpp",
         "key_config.proto",
         "key_proto_handler.cpp",
diff --git a/keystore/KeyStore.cpp b/keystore/KeyStore.cpp
index f197d91..428b51e 100644
--- a/keystore/KeyStore.cpp
+++ b/keystore/KeyStore.cpp
@@ -63,9 +63,9 @@
     return (*const_cast<KeymasterDevices*>(this))[secLevel];
 }
 
-KeyStore::KeyStore(Entropy* entropy, const KeymasterDevices& kmDevices,
+KeyStore::KeyStore(const KeymasterDevices& kmDevices,
                    SecurityLevel minimalAllowedSecurityLevelForNewKeys)
-    : mEntropy(entropy), mKmDevices(kmDevices),
+    : mKmDevices(kmDevices),
       mAllowNewFallback(minimalAllowedSecurityLevelForNewKeys == SecurityLevel::SOFTWARE) {
     memset(&mMetaData, '\0', sizeof(mMetaData));
 }
@@ -89,7 +89,7 @@
 
 ResponseCode KeyStore::initializeUser(const android::String8& pw, uid_t userId) {
     UserState* userState = getUserState(userId);
-    return userState->initialize(pw, mEntropy);
+    return userState->initialize(pw);
 }
 
 ResponseCode KeyStore::copyMasterKey(uid_t srcUser, uid_t dstUser) {
@@ -100,12 +100,12 @@
 
 ResponseCode KeyStore::writeMasterKey(const android::String8& pw, uid_t userId) {
     UserState* userState = getUserState(userId);
-    return userState->writeMasterKey(pw, mEntropy);
+    return userState->writeMasterKey(pw);
 }
 
 ResponseCode KeyStore::readMasterKey(const android::String8& pw, uid_t userId) {
     UserState* userState = getUserState(userId);
-    return userState->readMasterKey(pw, mEntropy);
+    return userState->readMasterKey(pw);
 }
 
 /* Here is the encoding of keys. This is necessary in order to allow arbitrary
@@ -360,8 +360,7 @@
 
 ResponseCode KeyStore::put(const char* filename, Blob* keyBlob, uid_t userId) {
     UserState* userState = getUserState(userId);
-    return keyBlob->writeBlob(filename, userState->getEncryptionKey(), userState->getState(),
-                              mEntropy);
+    return keyBlob->writeBlob(filename, userState->getEncryptionKey(), userState->getState());
 }
 
 static NullOr<std::tuple<uid_t, std::string>> filename2UidAlias(const std::string& filename);
diff --git a/keystore/KeyStore.h b/keystore/KeyStore.h
index 23476d2..f0fe9d3 100644
--- a/keystore/KeyStore.h
+++ b/keystore/KeyStore.h
@@ -40,7 +40,7 @@
 
 class KeyStore {
   public:
-    KeyStore(Entropy* entropy, const KeymasterDevices& kmDevices,
+    KeyStore(const KeymasterDevices& kmDevices,
              SecurityLevel minimalAllowedSecurityLevelForNewKeys);
     ~KeyStore();
 
@@ -140,7 +140,6 @@
     static const char* kMetaDataFile;
     static const android::String16 kRsaKeyType;
     static const android::String16 kEcKeyType;
-    Entropy* mEntropy;
 
     KeymasterDevices mKmDevices;
     bool mAllowNewFallback;
diff --git a/keystore/blob.cpp b/keystore/blob.cpp
index d21c691..ca5cb74 100644
--- a/keystore/blob.cpp
+++ b/keystore/blob.cpp
@@ -19,12 +19,12 @@
 #include <arpa/inet.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <openssl/rand.h>
 #include <string.h>
 
 #include <cutils/log.h>
 
 #include "blob.h"
-#include "entropy.h"
 
 #include "keystore_utils.h"
 
@@ -205,8 +205,7 @@
     }
 }
 
-ResponseCode Blob::writeBlob(const std::string& filename, const uint8_t* aes_key, State state,
-                             Entropy* entropy) {
+ResponseCode Blob::writeBlob(const std::string& filename, const uint8_t* aes_key, State state) {
     ALOGV("writing blob %s", filename.c_str());
 
     const size_t dataLength = mBlob.length;
@@ -219,7 +218,7 @@
         }
 
         memset(mBlob.initialization_vector, 0, AES_BLOCK_SIZE);
-        if (!entropy->generate_random_data(mBlob.initialization_vector, kGcmIvSizeBytes)) {
+        if (!RAND_bytes(mBlob.initialization_vector, kGcmIvSizeBytes)) {
             ALOGW("Could not read random data for: %s", filename.c_str());
             return ResponseCode::SYSTEM_ERROR;
         }
diff --git a/keystore/blob.h b/keystore/blob.h
index 665e07a..6a52ca4 100644
--- a/keystore/blob.h
+++ b/keystore/blob.h
@@ -82,7 +82,6 @@
     TYPE_KEY_CHARACTERISTICS = 5,
 } BlobType;
 
-class Entropy;
 
 class Blob {
   public:
@@ -121,8 +120,7 @@
     keystore::SecurityLevel getSecurityLevel() const;
     void setSecurityLevel(keystore::SecurityLevel);
 
-    ResponseCode writeBlob(const std::string& filename, const uint8_t* aes_key, State state,
-                           Entropy* entropy);
+    ResponseCode writeBlob(const std::string& filename, const uint8_t* aes_key, State state);
     ResponseCode readBlob(const std::string& filename, const uint8_t* aes_key, State state);
 
   private:
diff --git a/keystore/entropy.cpp b/keystore/entropy.cpp
deleted file mode 100644
index 1bfe9a1..0000000
--- a/keystore/entropy.cpp
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- * Copyright (C) 2016 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.
- */
-
-#define LOG_TAG "keystore"
-
-#include "entropy.h"
-
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-
-#include <cutils/log.h>
-
-#include "keystore_utils.h"
-
-Entropy::~Entropy() {
-    if (mRandom >= 0) {
-        close(mRandom);
-    }
-}
-
-bool Entropy::open() {
-    const char* randomDevice = "/dev/urandom";
-    mRandom = TEMP_FAILURE_RETRY(::open(randomDevice, O_RDONLY));
-    if (mRandom < 0) {
-        ALOGE("open: %s: %s", randomDevice, strerror(errno));
-        return false;
-    }
-    return true;
-}
-
-bool Entropy::generate_random_data(uint8_t* data, size_t size) const {
-    return (readFully(mRandom, data, size) == size);
-}
diff --git a/keystore/entropy.h b/keystore/entropy.h
deleted file mode 100644
index 0e4d1b2..0000000
--- a/keystore/entropy.h
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Copyright (C) 2016 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.
- */
-
-#ifndef KEYSTORE_ENTROPY_H_
-#define KEYSTORE_ENTROPY_H_
-
-#include <stdint.h>
-
-class Entropy {
-  public:
-    Entropy() : mRandom(-1) {}
-    ~Entropy();
-
-    bool open();
-    bool generate_random_data(uint8_t* data, size_t size) const;
-
-  private:
-    int mRandom;
-};
-
-#endif  // KEYSTORE_ENTROPY_H_
diff --git a/keystore/keystore_main.cpp b/keystore/keystore_main.cpp
index 82d4e69..52e83c8 100644
--- a/keystore/keystore_main.cpp
+++ b/keystore/keystore_main.cpp
@@ -32,7 +32,6 @@
 #include <keystore/keystore_return_types.h>
 
 #include "KeyStore.h"
-#include "entropy.h"
 #include "key_store_service.h"
 #include "legacy_keymaster_device_wrapper.h"
 #include "permissions.h"
@@ -136,9 +135,6 @@
     CHECK(argc >= 2) << "A directory must be specified!";
     CHECK(chdir(argv[1]) != -1) << "chdir: " << argv[1] << ": " << strerror(errno);
 
-    Entropy entropy;
-    CHECK(entropy.open()) << "Failed to open entropy source.";
-
     auto kmDevices = initializeKeymasters();
 
     CHECK(kmDevices[SecurityLevel::SOFTWARE]) << "Missing software Keymaster device";
@@ -155,7 +151,7 @@
     SecurityLevel minimalAllowedSecurityLevelForNewKeys =
         halVersion.majorVersion >= 2 ? SecurityLevel::TRUSTED_ENVIRONMENT : SecurityLevel::SOFTWARE;
 
-    keystore::KeyStore keyStore(&entropy, kmDevices, minimalAllowedSecurityLevelForNewKeys);
+    keystore::KeyStore keyStore(kmDevices, minimalAllowedSecurityLevelForNewKeys);
     keyStore.initialize();
     android::sp<android::IServiceManager> sm = android::defaultServiceManager();
     android::sp<keystore::KeyStoreService> service = new keystore::KeyStoreService(&keyStore);
diff --git a/keystore/user_state.cpp b/keystore/user_state.cpp
index 5f9cd5f..b62598d 100644
--- a/keystore/user_state.cpp
+++ b/keystore/user_state.cpp
@@ -25,6 +25,7 @@
 #include <sys/stat.h>
 
 #include <openssl/evp.h>
+#include <openssl/rand.h>
 
 #include <cutils/log.h>
 
@@ -76,11 +77,11 @@
     return unlink(mMasterKeyFile) == 0 || errno == ENOENT;
 }
 
-ResponseCode UserState::initialize(const android::String8& pw, Entropy* entropy) {
-    if (!generateMasterKey(entropy)) {
+ResponseCode UserState::initialize(const android::String8& pw) {
+    if (!generateMasterKey()) {
         return ResponseCode::SYSTEM_ERROR;
     }
-    ResponseCode response = writeMasterKey(pw, entropy);
+    ResponseCode response = writeMasterKey(pw);
     if (response != ResponseCode::NO_ERROR) {
         return response;
     }
@@ -130,14 +131,14 @@
     return ResponseCode::NO_ERROR;
 }
 
-ResponseCode UserState::writeMasterKey(const android::String8& pw, Entropy* entropy) {
+ResponseCode UserState::writeMasterKey(const android::String8& pw) {
     uint8_t passwordKey[MASTER_KEY_SIZE_BYTES];
     generateKeyFromPassword(passwordKey, MASTER_KEY_SIZE_BYTES, pw, mSalt);
     Blob masterKeyBlob(mMasterKey, sizeof(mMasterKey), mSalt, sizeof(mSalt), TYPE_MASTER_KEY);
-    return masterKeyBlob.writeBlob(mMasterKeyFile, passwordKey, STATE_NO_ERROR, entropy);
+    return masterKeyBlob.writeBlob(mMasterKeyFile, passwordKey, STATE_NO_ERROR);
 }
 
-ResponseCode UserState::readMasterKey(const android::String8& pw, Entropy* entropy) {
+ResponseCode UserState::readMasterKey(const android::String8& pw) {
     int in = TEMP_FAILURE_RETRY(open(mMasterKeyFile, O_RDONLY));
     if (in < 0) {
         return ResponseCode::SYSTEM_ERROR;
@@ -167,10 +168,10 @@
     if (response == ResponseCode::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(entropy)) {
+            if (!generateSalt()) {
                 return ResponseCode::SYSTEM_ERROR;
             }
-            response = writeMasterKey(pw, entropy);
+            response = writeMasterKey(pw);
         }
         if (response == ResponseCode::NO_ERROR) {
             memcpy(mMasterKey, masterKeyBlob.getValue(), MASTER_KEY_SIZE_BYTES);
@@ -237,15 +238,15 @@
                            8192, keySize, key);
 }
 
-bool UserState::generateSalt(Entropy* entropy) {
-    return entropy->generate_random_data(mSalt, sizeof(mSalt));
+bool UserState::generateSalt() {
+    return RAND_bytes(mSalt, sizeof(mSalt));
 }
 
-bool UserState::generateMasterKey(Entropy* entropy) {
-    if (!entropy->generate_random_data(mMasterKey, sizeof(mMasterKey))) {
+bool UserState::generateMasterKey() {
+    if (!RAND_bytes(mMasterKey, sizeof(mMasterKey))) {
         return false;
     }
-    if (!generateSalt(entropy)) {
+    if (!generateSalt()) {
         return false;
     }
     return true;
diff --git a/keystore/user_state.h b/keystore/user_state.h
index c28f7b8..e1d48bd 100644
--- a/keystore/user_state.h
+++ b/keystore/user_state.h
@@ -25,7 +25,6 @@
 
 #include <keystore/keystore.h>
 
-#include "entropy.h"
 
 class UserState {
   public:
@@ -47,12 +46,12 @@
     void zeroizeMasterKeysInMemory();
     bool deleteMasterKey();
 
-    ResponseCode initialize(const android::String8& pw, Entropy* entropy);
+    ResponseCode initialize(const android::String8& pw);
 
     ResponseCode copyMasterKey(UserState* src);
     ResponseCode copyMasterKeyFile(UserState* src);
-    ResponseCode writeMasterKey(const android::String8& pw, Entropy* entropy);
-    ResponseCode readMasterKey(const android::String8& pw, Entropy* entropy);
+    ResponseCode writeMasterKey(const android::String8& pw);
+    ResponseCode readMasterKey(const android::String8& pw);
 
     auto& getEncryptionKey() const { return mMasterKey; }
 
@@ -67,8 +66,8 @@
 
     void generateKeyFromPassword(uint8_t* key, ssize_t keySize, const android::String8& pw,
                                  uint8_t* salt);
-    bool generateSalt(Entropy* entropy);
-    bool generateMasterKey(Entropy* entropy);
+    bool generateSalt();
+    bool generateMasterKey();
     void setupMasterKeys();
 
     uid_t mUserId;