diff --git a/keystore-engine/android_engine.cpp b/keystore-engine/android_engine.cpp
new file mode 100644
index 0000000..ee16312
--- /dev/null
+++ b/keystore-engine/android_engine.cpp
@@ -0,0 +1,452 @@
+/* Copyright 2014 The Android Open Source Project
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
+
+#include <UniquePtr.h>
+
+#include <sys/socket.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <openssl/bn.h>
+#include <openssl/ec.h>
+#include <openssl/ec_key.h>
+#include <openssl/ecdsa.h>
+#include <openssl/engine.h>
+#include <openssl/evp.h>
+#include <openssl/rsa.h>
+#include <openssl/x509.h>
+
+#include <binder/IServiceManager.h>
+#include <keystore/keystore.h>
+#include <keystore/IKeystoreService.h>
+
+using namespace android;
+
+namespace {
+
+extern const RSA_METHOD keystore_rsa_method;
+extern const ECDSA_METHOD keystore_ecdsa_method;
+
+/* key_id_dup is called when one of the RSA or EC_KEY objects is duplicated. */
+int key_id_dup(CRYPTO_EX_DATA* to,
+               const CRYPTO_EX_DATA* from,
+               void** from_d,
+               int index,
+               long argl,
+               void* argp) {
+    char *key_id = reinterpret_cast<char *>(*from_d);
+    if (key_id != NULL) {
+        *from_d = strdup(key_id);
+    }
+    return 1;
+}
+
+/* key_id_free is called when one of the RSA, DSA or EC_KEY object is freed. */
+void key_id_free(void* parent,
+                 void* ptr,
+                 CRYPTO_EX_DATA* ad,
+                 int index,
+                 long argl,
+                 void* argp) {
+    char *key_id = reinterpret_cast<char *>(ptr);
+    free(key_id);
+}
+
+/* KeystoreEngine is a BoringSSL ENGINE that implements RSA and ECDSA by
+ * forwarding the requested operations to Keystore. */
+class KeystoreEngine {
+ public:
+  KeystoreEngine()
+      : rsa_index_(RSA_get_ex_new_index(0 /* argl */,
+                                        NULL /* argp */,
+                                        NULL /* new_func */,
+                                        key_id_dup,
+                                        key_id_free)),
+        ec_key_index_(EC_KEY_get_ex_new_index(0 /* argl */,
+                                              NULL /* argp */,
+                                              NULL /* new_func */,
+                                              key_id_dup,
+                                              key_id_free)),
+        engine_(ENGINE_new()) {
+    ENGINE_set_RSA_method(
+        engine_, &keystore_rsa_method, sizeof(keystore_rsa_method));
+    ENGINE_set_ECDSA_method(
+        engine_, &keystore_ecdsa_method, sizeof(keystore_ecdsa_method));
+  }
+
+  int rsa_ex_index() const { return rsa_index_; }
+  int ec_key_ex_index() const { return ec_key_index_; }
+
+  const ENGINE* engine() const { return engine_; }
+
+ private:
+  const int rsa_index_;
+  const int ec_key_index_;
+  ENGINE* const engine_;
+};
+
+pthread_once_t g_keystore_engine_once = PTHREAD_ONCE_INIT;
+KeystoreEngine *g_keystore_engine;
+
+/* init_keystore_engine is called to initialize |g_keystore_engine|. This
+ * should only be called by |pthread_once|. */
+void init_keystore_engine() {
+    g_keystore_engine = new KeystoreEngine;
+}
+
+/* ensure_keystore_engine ensures that |g_keystore_engine| is pointing to a
+ * valid |KeystoreEngine| object and creates one if not. */
+void ensure_keystore_engine() {
+    pthread_once(&g_keystore_engine_once, init_keystore_engine);
+}
+
+/* Many OpenSSL APIs take ownership of an argument on success but don't free
+ * the argument on failure. This means we need to tell our scoped pointers when
+ * we've transferred ownership, without triggering a warning by not using the
+ * result of release(). */
+#define OWNERSHIP_TRANSFERRED(obj) \
+    typeof (obj.release()) _dummy __attribute__((unused)) = obj.release()
+
+const char* rsa_get_key_id(const RSA* rsa) {
+  return reinterpret_cast<char*>(
+      RSA_get_ex_data(rsa, g_keystore_engine->rsa_ex_index()));
+}
+
+/* rsa_private_transform takes a big-endian integer from |in|, calculates the
+ * d'th power of it, modulo the RSA modulus, and writes the result as a
+ * big-endian integer to |out|. Both |in| and |out| are |len| bytes long. It
+ * returns one on success and zero otherwise. */
+int rsa_private_transform(RSA *rsa, uint8_t *out, const uint8_t *in, size_t len) {
+    ALOGV("rsa_private_transform(%p, %p, %p, %u)", rsa, out, in, (unsigned) len);
+
+    const char *key_id = rsa_get_key_id(rsa);
+    if (key_id == NULL) {
+        ALOGE("key had no key_id!");
+        return 0;
+    }
+
+    sp<IServiceManager> sm = defaultServiceManager();
+    sp<IBinder> binder = sm->getService(String16("android.security.keystore"));
+    sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);
+
+    if (service == NULL) {
+        ALOGE("could not contact keystore");
+        return 0;
+    }
+
+    uint8_t* reply = NULL;
+    size_t reply_len;
+    int32_t ret = service->sign(String16(key_id), in, len, &reply, &reply_len);
+    if (ret < 0) {
+        ALOGW("There was an error during rsa_decrypt: could not connect");
+        return 0;
+    } else if (ret != 0) {
+        ALOGW("Error during sign from keystore: %d", ret);
+        return 0;
+    } else if (reply_len == 0) {
+        ALOGW("No valid signature returned");
+        free(reply);
+        return 0;
+    }
+
+    if (reply_len > len) {
+        /* The result of the RSA operation can never be larger than the size of
+         * the modulus so we assume that the result has extra zeros on the
+         * left. This provides attackers with an oracle, but there's nothing
+         * that we can do about it here. */
+        memcpy(out, reply + reply_len - len, len);
+    } else if (reply_len < len) {
+        /* If the Keystore implementation returns a short value we assume that
+         * it's because it removed leading zeros from the left side. This is
+         * bad because it provides attackers with an oracle but we cannot do
+         * anything about a broken Keystore implementation here. */
+        memset(out, 0, len);
+        memcpy(out + len - reply_len, reply, reply_len);
+    } else {
+        memcpy(out, reply, len);
+    }
+
+    free(reply);
+
+    ALOGV("rsa=%p keystore_rsa_priv_dec successful", rsa);
+    return 1;
+}
+
+const struct rsa_meth_st keystore_rsa_method = {
+  {
+    0 /* references */,
+    1 /* is_static */,
+  },
+  NULL /* app_data */,
+
+  NULL /* init */,
+  NULL /* finish */,
+
+  NULL /* size */,
+
+  NULL /* sign */,
+  NULL /* verify */,
+
+  NULL /* encrypt */,
+  NULL /* sign_raw */,
+  NULL /* decrypt */,
+  NULL /* verify_raw */,
+
+  rsa_private_transform,
+
+  NULL /* mod_exp */,
+  NULL /* bn_mod_exp */,
+
+  RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_OPAQUE | RSA_FLAG_EXT_PKEY,
+
+  NULL /* keygen */,
+};
+
+const char* ecdsa_get_key_id(const EC_KEY* ec_key) {
+    return reinterpret_cast<char*>(
+        EC_KEY_get_ex_data(ec_key, g_keystore_engine->ec_key_ex_index()));
+}
+
+/* ecdsa_sign signs |digest_len| bytes from |digest| with |ec_key| and writes
+ * the resulting signature (an ASN.1 encoded blob) to |sig|. It returns one on
+ * success and zero otherwise. */
+static int ecdsa_sign(const uint8_t* digest, size_t digest_len, uint8_t* sig,
+                      unsigned int* sig_len, EC_KEY* ec_key) {
+    ALOGV("ecdsa_sign(%p, %u, %p)", digest, (unsigned) digest_len, ec_key);
+
+    const char *key_id = ecdsa_get_key_id(ec_key);
+    if (key_id == NULL) {
+        ALOGE("key had no key_id!");
+        return 0;
+    }
+
+    sp<IServiceManager> sm = defaultServiceManager();
+    sp<IBinder> binder = sm->getService(String16("android.security.keystore"));
+    sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);
+
+    if (service == NULL) {
+        ALOGE("could not contact keystore");
+        return 0;
+    }
+
+    size_t ecdsa_size = ECDSA_size(ec_key);
+
+    uint8_t* reply = NULL;
+    size_t reply_len;
+    int32_t ret = service->sign(String16(reinterpret_cast<const char*>(key_id)),
+                                digest, digest_len, &reply, &reply_len);
+    if (ret < 0) {
+        ALOGW("There was an error during ecdsa_sign: could not connect");
+        return 0;
+    } else if (ret != 0) {
+        ALOGW("Error during sign from keystore: %d", ret);
+        return 0;
+    } else if (reply_len == 0) {
+        ALOGW("No valid signature returned");
+        free(reply);
+        return 0;
+    } else if (reply_len > ecdsa_size) {
+        ALOGW("Signature is too large");
+        free(reply);
+        return 0;
+    }
+
+    memcpy(sig, reply, reply_len);
+    *sig_len = reply_len;
+
+    ALOGV("ecdsa_sign(%p, %u, %p) => success", digest, (unsigned)digest_len,
+          ec_key);
+    return 1;
+}
+
+const ECDSA_METHOD keystore_ecdsa_method = {
+    {
+     0 /* references */,
+     1 /* is_static */
+    } /* common */,
+    NULL /* app_data */,
+
+    NULL /* init */,
+    NULL /* finish */,
+    NULL /* group_order_size */,
+    ecdsa_sign,
+    NULL /* verify */,
+    ECDSA_FLAG_OPAQUE,
+};
+
+struct EVP_PKEY_Delete {
+    void operator()(EVP_PKEY* p) const {
+        EVP_PKEY_free(p);
+    }
+};
+typedef UniquePtr<EVP_PKEY, EVP_PKEY_Delete> Unique_EVP_PKEY;
+
+struct RSA_Delete {
+    void operator()(RSA* p) const {
+        RSA_free(p);
+    }
+};
+typedef UniquePtr<RSA, RSA_Delete> Unique_RSA;
+
+struct EC_KEY_Delete {
+    void operator()(EC_KEY* ec) const {
+        EC_KEY_free(ec);
+    }
+};
+typedef UniquePtr<EC_KEY, EC_KEY_Delete> Unique_EC_KEY;
+
+/* wrap_rsa returns an |EVP_PKEY| that contains an RSA key where the public
+ * part is taken from |public_rsa| and the private operations are forwarded to
+ * KeyStore and operate on the key named |key_id|. */
+static EVP_PKEY *wrap_rsa(const char *key_id, const RSA *public_rsa) {
+    Unique_RSA rsa(RSA_new_method(g_keystore_engine->engine()));
+    if (rsa.get() == NULL) {
+        return NULL;
+    }
+
+    char *key_id_copy = strdup(key_id);
+    if (key_id_copy == NULL) {
+        return NULL;
+    }
+
+    if (!RSA_set_ex_data(rsa.get(), g_keystore_engine->rsa_ex_index(),
+                         key_id_copy)) {
+        free(key_id_copy);
+        return NULL;
+    }
+
+    rsa->n = BN_dup(public_rsa->n);
+    rsa->e = BN_dup(public_rsa->e);
+    if (rsa->n == NULL || rsa->e == NULL) {
+        return NULL;
+    }
+
+    Unique_EVP_PKEY result(EVP_PKEY_new());
+    if (result.get() == NULL ||
+        !EVP_PKEY_assign_RSA(result.get(), rsa.get())) {
+        return NULL;
+    }
+    OWNERSHIP_TRANSFERRED(rsa);
+
+    return result.release();
+}
+
+/* wrap_ecdsa returns an |EVP_PKEY| that contains an ECDSA key where the public
+ * part is taken from |public_rsa| and the private operations are forwarded to
+ * KeyStore and operate on the key named |key_id|. */
+static EVP_PKEY *wrap_ecdsa(const char *key_id, const EC_KEY *public_ecdsa) {
+    Unique_EC_KEY ec(EC_KEY_new_method(g_keystore_engine->engine()));
+    if (ec.get() == NULL) {
+        return NULL;
+    }
+
+    if (!EC_KEY_set_group(ec.get(), EC_KEY_get0_group(public_ecdsa)) ||
+        !EC_KEY_set_public_key(ec.get(), EC_KEY_get0_public_key(public_ecdsa))) {
+        return NULL;
+    }
+
+    char *key_id_copy = strdup(key_id);
+    if (key_id_copy == NULL) {
+        return NULL;
+    }
+
+    if (!EC_KEY_set_ex_data(ec.get(), g_keystore_engine->ec_key_ex_index(),
+                            key_id_copy)) {
+        free(key_id_copy);
+        return NULL;
+    }
+
+    Unique_EVP_PKEY result(EVP_PKEY_new());
+    if (result.get() == NULL ||
+        !EVP_PKEY_assign_EC_KEY(result.get(), ec.get())) {
+        return NULL;
+    }
+    OWNERSHIP_TRANSFERRED(ec);
+
+    return result.release();
+}
+
+}  /* anonymous namespace */
+
+extern "C" {
+
+EVP_PKEY* EVP_PKEY_from_keystore(const char* key_id) __attribute__((visibility("default")));
+
+/* EVP_PKEY_from_keystore returns an |EVP_PKEY| that contains either an RSA or
+ * ECDSA key where the public part of the key reflects the value of the key
+ * named |key_id| in Keystore and the private operations are forwarded onto
+ * KeyStore. */
+EVP_PKEY* EVP_PKEY_from_keystore(const char* key_id) {
+    ALOGV("EVP_PKEY_from_keystore(\"%s\")", key_id);
+
+    sp<IServiceManager> sm = defaultServiceManager();
+    sp<IBinder> binder = sm->getService(String16("android.security.keystore"));
+    sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);
+
+    if (service == NULL) {
+        ALOGE("could not contact keystore");
+        return 0;
+    }
+
+    uint8_t *pubkey = NULL;
+    size_t pubkey_len;
+    int32_t ret = service->get_pubkey(String16(key_id), &pubkey, &pubkey_len);
+    if (ret < 0) {
+        ALOGW("could not contact keystore");
+        return NULL;
+    } else if (ret != 0) {
+        ALOGW("keystore reports error: %d", ret);
+        return NULL;
+    }
+
+    const uint8_t *inp = pubkey;
+    Unique_EVP_PKEY pkey(d2i_PUBKEY(NULL, &inp, pubkey_len));
+    free(pubkey);
+    if (pkey.get() == NULL) {
+        ALOGW("Cannot convert pubkey");
+        return NULL;
+    }
+
+    ensure_keystore_engine();
+
+    EVP_PKEY *result;
+    switch (EVP_PKEY_type(pkey->type)) {
+    case EVP_PKEY_RSA: {
+        Unique_RSA public_rsa(EVP_PKEY_get1_RSA(pkey.get()));
+        result = wrap_rsa(key_id, public_rsa.get());
+        break;
+    }
+    case EVP_PKEY_EC: {
+        Unique_EC_KEY public_ecdsa(EVP_PKEY_get1_EC_KEY(pkey.get()));
+        result = wrap_ecdsa(key_id, public_ecdsa.get());
+        break;
+    }
+    default:
+        ALOGE("Unsupported key type %d", EVP_PKEY_type(pkey->type));
+        result = NULL;
+    }
+
+    return result;
+}
+
+}  // extern "C"