vici: Add command to load a private key from a token

PINs are stored in a "hidden" credential set, so that its shared
secrets are not exposed via VICI.  Since they are not explicitly loaded as
shared secrets via VICI a client might consider them as removed secrets and
remove them.

src/libcharon/plugins/vici/README.md

@@ -491,6 +491,24 @@ including keys found in other backends.
 		]
 	}
 
+### load-token() ###
+
+Load a private key located on a token into the daemon.  Such keys may be listed
+and unloaded using the _get-keys_ and _unload-key_ commands, respectively (based
+on the key identifier derived from the public key).
+
+	{
+		handle = <hex-encoded CKA_ID of the private key on token>
+		slot = <optional slot number>
+		module = <optional PKCS#11 module>
+		pin = <optional PIN to access the key, has to be provided via other
+			   means if not given>
+	} => {
+		success = <yes or no>
+		errmsg = <error string on failure>
+		id = <hex-encoded SHA-1 key identifier of the public key on success>
+	}
+
 ### load-shared() ###
 
 Load a shared IKE PSK, EAP or XAuth secret into the daemon.

src/libcharon/plugins/vici/vici_cred.c

@@ -56,6 +56,11 @@ struct private_vici_cred_t {
 	 */
 	mem_cred_t *creds;
 
+	/**
+	 * separate credential set for token PINs
+	 */
+	mem_cred_t *pins;
+
 	/**
 	 * cache CRLs to disk?
 	 */
@@ -255,7 +260,7 @@ CALLBACK(unload_key, vici_message_t*,
 	private_vici_cred_t *this, char *name, u_int id, vici_message_t *message)
 {
 	chunk_t keyid;
-	char *hex, *msg = NULL;
+	char buf[BUF_LEN], *hex, *msg = NULL;
 
 	hex = message->get_str(message, NULL, "id");
 	if (!hex)
@@ -263,8 +268,13 @@ CALLBACK(unload_key, vici_message_t*,
 		return create_reply("key id missing");
 	}
 	keyid = chunk_from_hex(chunk_from_str(hex), NULL);
-	DBG1(DBG_CFG, "unloaded private key with id %+B", &keyid);
+	snprintf(buf, sizeof(buf), "%+B", &keyid);
-	if (!this->creds->remove_key(this->creds, keyid))
+	DBG1(DBG_CFG, "unloaded private key with id %s", buf);
+	if (this->creds->remove_key(this->creds, keyid))
+	{	/* also remove any potential PIN associated with this id */
+		this->pins->remove_shared_unique(this->pins, buf);
+	}
+	else
 	{
 		msg = "key not found";
 	}
@@ -298,6 +308,87 @@ CALLBACK(get_keys, vici_message_t*,
 	return builder->finalize(builder);
 }
 
+CALLBACK(load_token, vici_message_t*,
+	private_vici_cred_t *this, char *name, u_int id, vici_message_t *message)
+{
+	vici_builder_t *builder;
+	private_key_t *key;
+	shared_key_t *shared = NULL;
+	identification_t *owner;
+	mem_cred_t *set = NULL;
+	chunk_t handle, fp;
+	char buf[BUF_LEN], *hex, *module, *pin, *unique = NULL;
+	int slot;
+
+	hex = message->get_str(message, NULL, "handle");
+	if (!hex)
+	{
+		return create_reply("keyid missing");
+	}
+	handle = chunk_from_hex(chunk_from_str(hex), NULL);
+	slot = message->get_int(message, -1, "slot");
+	module = message->get_str(message, NULL, "module");
+	pin = message->get_str(message, NULL, "pin");
+
+	if (pin)
+	{	/* provide the pin in a temporary credential set to access the key */
+		shared = shared_key_create(SHARED_PIN, chunk_clone(chunk_from_str(pin)));
+		owner = identification_create_from_encoding(ID_KEY_ID, handle);
+		set = mem_cred_create();
+		set->add_shared(set, shared->get_ref(shared), owner, NULL);
+		lib->credmgr->add_local_set(lib->credmgr, &set->set, FALSE);
+	}
+	if (slot >= 0)
+	{
+		key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY, KEY_ANY,
+						BUILD_PKCS11_KEYID, handle,
+						BUILD_PKCS11_SLOT, slot,
+						module ? BUILD_PKCS11_MODULE : BUILD_END, module,
+						BUILD_END);
+	}
+	else
+	{
+		key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY, KEY_ANY,
+						BUILD_PKCS11_KEYID, handle,
+						module ? BUILD_PKCS11_MODULE : BUILD_END, module,
+						BUILD_END);
+	}
+	if (set)
+	{
+		lib->credmgr->remove_local_set(lib->credmgr, &set->set);
+		set->destroy(set);
+	}
+	if (!key)
+	{
+		chunk_free(&handle);
+		DESTROY_IF(shared);
+		return create_reply("loading private key from token failed");
+	}
+	builder = vici_builder_create();
+	builder->add_kv(builder, "success", "yes");
+	if (key->get_fingerprint(key, KEYID_PUBKEY_SHA1, &fp))
+	{
+		snprintf(buf, sizeof(buf), "%+B", &fp);
+		builder->add_kv(builder, "id", "%s", buf);
+		unique = buf;
+	}
+	if (shared && unique)
+	{	/* use the handle as owner, but the key identifier as unique ID */
+		owner = identification_create_from_encoding(ID_KEY_ID, handle);
+		this->pins->add_shared_unique(this->pins, unique, shared,
+									linked_list_create_with_items(owner, NULL));
+	}
+	else
+	{
+		DESTROY_IF(shared);
+	}
+	DBG1(DBG_CFG, "loaded %N private key from token", key_type_names,
+		 key->get_type(key));
+	this->creds->add_key(this->creds, key);
+	chunk_free(&handle);
+	return builder->finalize(builder);
+}
+
 CALLBACK(shared_owners, bool,
 	linked_list_t *owners, vici_message_t *message, char *name, chunk_t value)
 {
@@ -474,6 +565,7 @@ static void manage_commands(private_vici_cred_t *this, bool reg)
 	manage_command(this, "load-key", load_key, reg);
 	manage_command(this, "unload-key", unload_key, reg);
 	manage_command(this, "get-keys", get_keys, reg);
+	manage_command(this, "load-token", load_token, reg);
 	manage_command(this, "load-shared", load_shared, reg);
 	manage_command(this, "unload-shared", unload_shared, reg);
 	manage_command(this, "get-shared", get_shared, reg);
@@ -492,6 +584,8 @@ METHOD(vici_cred_t, destroy, void,
 
 	lib->credmgr->remove_set(lib->credmgr, &this->creds->set);
 	this->creds->destroy(this->creds);
+	lib->credmgr->remove_set(lib->credmgr, &this->pins->set);
+	this->pins->destroy(this->pins);
 	free(this);
 }
 
@@ -516,6 +610,7 @@ vici_cred_t *vici_cred_create(vici_dispatcher_t *dispatcher)
 		},
 		.dispatcher = dispatcher,
 		.creds = mem_cred_create(),
+		.pins = mem_cred_create(),
 	);
 
 	if (lib->settings->get_bool(lib->settings, "%s.cache_crls", FALSE, lib->ns))
@@ -524,6 +619,7 @@ vici_cred_t *vici_cred_create(vici_dispatcher_t *dispatcher)
 		DBG1(DBG_CFG, "crl caching to %s enabled", CRL_DIR);
 	}
 	lib->credmgr->add_set(lib->credmgr, &this->creds->set);
+	lib->credmgr->add_set(lib->credmgr, &this->pins->set);
 
 	manage_commands(this, TRUE);