Add support for DSA and ECDSA key types
Change-Id: Ibee8d172eeb36f1a2e2ce62f275aea55ada5bcbf
diff --git a/keystore-engine/eng_keystore.cpp b/keystore-engine/eng_keystore.cpp
index 30cad7c..9397e53 100644
--- a/keystore-engine/eng_keystore.cpp
+++ b/keystore-engine/eng_keystore.cpp
@@ -30,9 +30,12 @@
#include <string.h>
#include <unistd.h>
-#include <openssl/objects.h>
+#include <openssl/dsa.h>
#include <openssl/engine.h>
+#include <openssl/ec.h>
#include <openssl/evp.h>
+#include <openssl/objects.h>
+#include <openssl/rsa.h>
//#define LOG_NDEBUG 0
#define LOG_TAG "OpenSSL-keystore"
@@ -50,6 +53,24 @@
const char* kKeystoreEngineId = "keystore";
static const char* kKeystoreEngineDesc = "Android keystore engine";
+
+/*
+ * ex_data index for keystore's key alias.
+ */
+int rsa_key_handle;
+int dsa_key_handle;
+
+
+/*
+ * Only initialize the *_key_handle once.
+ */
+static pthread_once_t key_handle_control = PTHREAD_ONCE_INIT;
+
+/*
+ * Used for generic EVP_PKEY* handling (only for EC stuff currently)
+ */
+static EVP_PKEY_METHOD* keystore_pkey_ec_methods;
+
/**
* 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,
@@ -58,6 +79,7 @@
#define OWNERSHIP_TRANSFERRED(obj) \
typeof (obj.release()) _dummy __attribute__((unused)) = obj.release()
+
struct ENGINE_Delete {
void operator()(ENGINE* p) const {
ENGINE_free(p);
@@ -72,6 +94,41 @@
};
typedef UniquePtr<EVP_PKEY, EVP_PKEY_Delete> Unique_EVP_PKEY;
+/**
+ * Called to initialize RSA's ex_data for the key_id handle. This should
+ * only be called when protected by a lock.
+ */
+static void init_key_handle() {
+ rsa_key_handle = RSA_get_ex_new_index(0, NULL, keyhandle_new, keyhandle_dup, keyhandle_free);
+ dsa_key_handle = DSA_get_ex_new_index(0, NULL, keyhandle_new, keyhandle_dup, keyhandle_free);
+}
+
+static int pkey_setup(ENGINE *e, EVP_PKEY *pkey, const char *key_id) {
+ int ret = 1;
+ switch (EVP_PKEY_type(pkey->type)) {
+ case EVP_PKEY_EC: {
+ 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);
+ }
+ } break;
+ default:
+ ALOGW("Unsupported key type during setup %d", EVP_PKEY_type(pkey->type));
+ return 0;
+ }
+
+ if (ret != 1) {
+ return ret;
+ }
+
+ ENGINE_init(e);
+ pkey->engine = e;
+
+ return 1;
+}
static EVP_PKEY* keystore_loadkey(ENGINE* e, const char* key_id, UI_METHOD* ui_method,
void* callback_data) {
@@ -113,10 +170,18 @@
}
switch (EVP_PKEY_type(pkey->type)) {
+ case EVP_PKEY_DSA: {
+ dsa_pkey_setup(e, pkey.get(), key_id);
+ break;
+ }
case EVP_PKEY_RSA: {
rsa_pkey_setup(e, pkey.get(), key_id);
break;
}
+ case EVP_PKEY_EC: {
+ pkey_setup(e, pkey.get(), key_id);
+ break;
+ }
default:
ALOGE("Unsupported key type %d", EVP_PKEY_type(pkey->type));
return NULL;
@@ -129,11 +194,107 @@
{0, NULL, NULL, 0}
};
+static uint8_t* get_key_id(EVP_PKEY* pkey) {
+ switch (EVP_PKEY_type(pkey->type)) {
+ case EVP_PKEY_EC: {
+ Unique_EC_KEY eckey(EVP_PKEY_get1_EC_KEY(pkey));
+ return reinterpret_cast<uint8_t*>(EC_KEY_get_key_method_data(eckey.get(),
+ ex_data_dup, ex_data_free, ex_data_clear_free));
+ } break;
+ }
+
+ return NULL;
+}
+
+static int keystore_pkey_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
+ const unsigned char *tbs, size_t tbs_len) {
+ EVP_PKEY* pkey = EVP_PKEY_CTX_get0_pkey(ctx);
+
+ const uint8_t* key_id = get_key_id(pkey);
+ if (key_id == NULL) {
+ ALOGW("key_id is empty");
+ 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 replyLen;
+ int32_t ret = service->sign(String16(reinterpret_cast<const char*>(key_id)), tbs, tbs_len,
+ &reply, &replyLen);
+ if (ret < 0) {
+ ALOGW("There was an error during signing: could not connect");
+ free(reply);
+ return 0;
+ } else if (ret != 0) {
+ ALOGW("Error during signing from keystore: %d", ret);
+ free(reply);
+ return 0;
+ } else if (replyLen <= 0) {
+ ALOGW("No valid signature returned");
+ return 0;
+ }
+
+ memcpy(sig, reply, replyLen);
+ free(reply);
+ *siglen = replyLen;
+
+ return 1;
+}
+
+static int register_pkey_methods(EVP_PKEY_METHOD** meth, int nid) {
+ *meth = EVP_PKEY_meth_new(nid, 0);
+ if (*meth == NULL) {
+ ALOGE("Failure allocating PKEY methods for NID %d", nid);
+ return 0;
+ }
+
+ const EVP_PKEY_METHOD* orig = EVP_PKEY_meth_find(nid);
+ EVP_PKEY_meth_copy(*meth, orig);
+
+ EVP_PKEY_meth_set_sign(*meth, NULL, keystore_pkey_sign);
+
+ return 1;
+}
+
+static int keystore_nids[] = {
+ EVP_PKEY_EC,
+};
+
+static int keystore_pkey_meths(ENGINE*, EVP_PKEY_METHOD** meth, const int **nids, int nid) {
+ if (meth == NULL) {
+ *nids = keystore_nids;
+ return sizeof(keystore_nids) / sizeof(keystore_nids[0]);
+ }
+
+ switch (nid) {
+ case EVP_PKEY_EC:
+ *meth = keystore_pkey_ec_methods;
+ return 1;
+ }
+
+ *meth = NULL;
+ return 0;
+}
+
static int keystore_engine_setup(ENGINE* e) {
ALOGV("keystore_engine_setup");
+ if (!register_pkey_methods(&keystore_pkey_ec_methods, EVP_PKEY_EC)) {
+ ALOGE("Could not set up keystore engine");
+ return 0;
+ }
+
if (!ENGINE_set_id(e, kKeystoreEngineId)
|| !ENGINE_set_name(e, kKeystoreEngineDesc)
+ || !ENGINE_set_pkey_meths(e, keystore_pkey_meths)
|| !ENGINE_set_load_privkey_function(e, keystore_loadkey)
|| !ENGINE_set_load_pubkey_function(e, keystore_loadkey)
|| !ENGINE_set_flags(e, 0)
@@ -142,7 +303,17 @@
return 0;
}
- if (!rsa_register(e)) {
+ /* We need a handle in the keys types as well for keygen if it's not already initialized. */
+ pthread_once(&key_handle_control, init_key_handle);
+ if ((rsa_key_handle < 0) || (dsa_key_handle < 0)) {
+ ALOGE("Could not set up ex_data index");
+ return 0;
+ }
+
+ if (!dsa_register(e)) {
+ ALOGE("DSA registration failed");
+ return 0;
+ } else if (!rsa_register(e)) {
ALOGE("RSA registration failed");
return 0;
}