Add support for DSA and ECDSA key types

Change-Id: Ibee8d172eeb36f1a2e2ce62f275aea55ada5bcbf
diff --git a/keystore-engine/dsa_meth.cpp b/keystore-engine/dsa_meth.cpp
new file mode 100644
index 0000000..6adfa2d
--- /dev/null
+++ b/keystore-engine/dsa_meth.cpp
@@ -0,0 +1,152 @@
+/*
+ * 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-dsa"
+#include <cutils/log.h>
+
+#include <binder/IServiceManager.h>
+#include <keystore/IKeystoreService.h>
+
+#include <openssl/dsa.h>
+#include <openssl/engine.h>
+
+#include "methods.h"
+
+
+using namespace android;
+
+struct DSA_SIG_Delete {
+    void operator()(DSA_SIG* p) const {
+        DSA_SIG_free(p);
+    }
+};
+typedef UniquePtr<DSA_SIG, struct DSA_SIG_Delete> Unique_DSA_SIG;
+
+static DSA_SIG* keystore_dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa) {
+    ALOGV("keystore_dsa_do_sign(%p, %d, %p)", dgst, dlen, dsa);
+
+    uint8_t* key_id = reinterpret_cast<uint8_t*>(DSA_get_ex_data(dsa, dsa_key_handle));
+    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 = DSA_size(dsa);
+
+    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_DSA_SIG dsa_sig(d2i_DSA_SIG(NULL,
+            const_cast<const unsigned char**>(reinterpret_cast<unsigned char**>(&reply)),
+            replyLen));
+    if (dsa_sig.get() == NULL) {
+        ALOGW("conversion from DER to DSA_SIG failed");
+        return 0;
+    }
+
+    ALOGV("keystore_dsa_do_sign(%p, %d, %p) => returning %p len %llu", dgst, dlen, dsa,
+            dsa_sig.get(), replyLen);
+    return dsa_sig.release();
+}
+
+static DSA_METHOD keystore_dsa_meth = {
+        kKeystoreEngineId, /* name */
+        keystore_dsa_do_sign, /* dsa_do_sign */
+        NULL, /* dsa_sign_setup */
+        NULL, /* dsa_do_verify */
+        NULL, /* dsa_mod_exp */
+        NULL, /* bn_mod_exp */
+        NULL, /* init */
+        NULL, /* finish */
+        0, /* flags */
+        NULL, /* app_data */
+        NULL, /* dsa_paramgen */
+        NULL, /* dsa_keygen */
+};
+
+static int register_dsa_methods() {
+    const DSA_METHOD* dsa_meth = DSA_OpenSSL();
+
+    keystore_dsa_meth.dsa_do_verify = dsa_meth->dsa_do_verify;
+
+    return 1;
+}
+
+int dsa_pkey_setup(ENGINE *e, EVP_PKEY *pkey, const char *key_id) {
+    Unique_DSA dsa(EVP_PKEY_get1_DSA(pkey));
+    if (!DSA_set_ex_data(dsa.get(), dsa_key_handle, reinterpret_cast<void*>(strdup(key_id)))) {
+        ALOGW("Could not set ex_data for loaded DSA key");
+        return 0;
+    }
+
+    DSA_set_method(dsa.get(), &keystore_dsa_meth);
+
+    /*
+     * "DSA_set_ENGINE()" should probably be an OpenSSL API. Since it isn't,
+     * and EVP_PKEY_free() calls ENGINE_finish(), we need to call ENGINE_init()
+     * here.
+     */
+    ENGINE_init(e);
+    dsa->engine = e;
+
+    return 1;
+}
+
+int dsa_register(ENGINE* e) {
+    if (!ENGINE_set_DSA(e, &keystore_dsa_meth)
+            || !register_dsa_methods()) {
+        ALOGE("Could not set up keystore DSA methods");
+        return 0;
+    }
+
+    return 1;
+}