Revert to old-style API for EC_KEY handling

Nothing using the EVP_PKEY correctly, so we should revert to the EC_KEY
and ECDSA interfaces. Unfortunately, the SSL client certificate library
uses EC_KEY directly, so just having the EVP_PKEY interface doesn't
work.

Remove the EVP_PKEY interface entirely because it just adds complexity
since the EC_KEY path will do the same thing.

Bug: 10655329
Change-Id: I97d17068297c33477b3b9f754f2713fdf258d646
diff --git a/keystore-engine/ecdsa_meth.cpp b/keystore-engine/ecdsa_meth.cpp
new file mode 100644
index 0000000..7b673a2
--- /dev/null
+++ b/keystore-engine/ecdsa_meth.cpp
@@ -0,0 +1,155 @@
+/*
+ * Copyright 2013 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 <utils/UniquePtr.h>
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "OpenSSL-keystore-ecdsa"
+#include <cutils/log.h>
+
+#include <binder/IServiceManager.h>
+#include <keystore/IKeystoreService.h>
+
+#include <openssl/ecdsa.h>
+#include <openssl/engine.h>
+
+// TODO replace this with real OpenSSL API when it exists
+#include "crypto/ec/ec_lcl.h"
+#include "crypto/ecdsa/ecs_locl.h"
+
+#include "methods.h"
+
+
+using namespace android;
+
+struct ECDSA_SIG_Delete {
+    void operator()(ECDSA_SIG* p) const {
+        ECDSA_SIG_free(p);
+    }
+};
+typedef UniquePtr<ECDSA_SIG, struct ECDSA_SIG_Delete> Unique_ECDSA_SIG;
+
+static ECDSA_SIG* keystore_ecdsa_do_sign(const unsigned char *dgst, int dlen,
+        const BIGNUM*, const BIGNUM*, EC_KEY *eckey) {
+    ALOGV("keystore_ecdsa_do_sign(%p, %d, %p)", dgst, dlen, eckey);
+
+    uint8_t* key_id = reinterpret_cast<uint8_t*>(EC_KEY_get_key_method_data(eckey,
+                ex_data_dup, ex_data_free, ex_data_clear_free));
+    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;
+    }
+
+    int num = ECDSA_size(eckey);
+
+    uint8_t* reply = NULL;
+    size_t replyLen;
+    int32_t ret = service->sign(String16(reinterpret_cast<const char*>(key_id)), dgst,
+            dlen, &reply, &replyLen);
+    if (ret < 0) {
+        ALOGW("There was an error during dsa_do_sign: could not connect");
+        return 0;
+    } else if (ret != 0) {
+        ALOGW("Error during sign from keystore: %d", ret);
+        return 0;
+    } else if (replyLen <= 0) {
+        ALOGW("No valid signature returned");
+        return 0;
+    } else if (replyLen > (size_t) num) {
+        ALOGW("Signature is too large");
+        return 0;
+    }
+
+    Unique_ECDSA_SIG ecdsa_sig(d2i_ECDSA_SIG(NULL,
+            const_cast<const unsigned char**>(reinterpret_cast<unsigned char**>(&reply)),
+            replyLen));
+    if (ecdsa_sig.get() == NULL) {
+        ALOGW("conversion from DER to ECDSA_SIG failed");
+        return 0;
+    }
+
+    ALOGV("keystore_ecdsa_do_sign(%p, %d, %p) => returning %p len %llu", dgst, dlen, eckey,
+            ecdsa_sig.get(), replyLen);
+    return ecdsa_sig.release();
+}
+
+static ECDSA_METHOD keystore_ecdsa_meth = {
+        kKeystoreEngineId, /* name */
+        keystore_ecdsa_do_sign, /* ecdsa_do_sign */
+        NULL, /* ecdsa_sign_setup */
+        NULL, /* ecdsa_do_verify */
+        0, /* flags */
+        NULL, /* app_data */
+};
+
+static int register_ecdsa_methods() {
+    const ECDSA_METHOD* ecdsa_meth = ECDSA_OpenSSL();
+
+    keystore_ecdsa_meth.ecdsa_do_verify = ecdsa_meth->ecdsa_do_verify;
+
+    return 1;
+}
+
+int ecdsa_pkey_setup(ENGINE *e, EVP_PKEY *pkey, const char *key_id) {
+    Unique_EC_KEY eckey(EVP_PKEY_get1_EC_KEY(pkey));
+    void* oldData = EC_KEY_insert_key_method_data(eckey.get(),
+            reinterpret_cast<void*>(strdup(key_id)), ex_data_dup, ex_data_free,
+            ex_data_clear_free);
+    if (oldData != NULL) {
+        free(oldData);
+    }
+
+    ECDSA_set_method(eckey.get(), &keystore_ecdsa_meth);
+
+    /*
+     * "ECDSA_set_ENGINE()" should probably be an OpenSSL API. Since it isn't,
+     * and EC_KEY_free() calls ENGINE_finish(), we need to call ENGINE_init()
+     * here.
+     */
+    ECDSA_DATA *ecdsa = ecdsa_check(eckey.get());
+    ENGINE_init(e);
+    ecdsa->engine = e;
+
+    return 1;
+}
+
+int ecdsa_register(ENGINE* e) {
+    if (!ENGINE_set_ECDSA(e, &keystore_ecdsa_meth)
+            || !register_ecdsa_methods()) {
+        ALOGE("Could not set up keystore ECDSA methods");
+        return 0;
+    }
+
+    return 1;
+}