Add --show-key and --machine-readable options

src/config.c

@@ -88,7 +88,9 @@ static void default_config(fastd_config *conf) {
 	conf->on_disestablish = NULL;
 	conf->on_disestablish_dir = NULL;
 
+	conf->machine_readable = false;
 	conf->generate_key = false;
+	conf->show_key = false;
 }
 
 static bool config_match(const char *opt, ...) {
@@ -345,7 +347,9 @@ static void count_peers(fastd_context *ctx, fastd_config *conf) {
 	OPTION_ARG(option_on_down, "--on-down", "<command>", "Sets a shell command to execute before interface destruction") \
 	OPTION_ARG(option_on_establish, "--on-establish", "<command>", "Sets a shell command to execute when a new connection is established") \
 	OPTION_ARG(option_on_disestablish, "--on-disestablish", "<command>", "Sets a shell command to execute when a connection is lost") \
-	OPTION(option_generate_key, "--generate-key", "Generates a new keypair")
+	OPTION(option_generate_key, "--generate-key", "Generates a new keypair") \
+	OPTION(option_show_key, "--show-key", "Shows the public key corresponding to the configured secret") \
+	OPTION(option_machine_readable, "--machine-readable", "Supresses output of explaining text in the --show-key and --generate-key commands")
 
 
 static void print_usage(const char *options, const char *message) {
@@ -551,6 +555,16 @@ static void option_on_disestablish(fastd_context *ctx, fastd_config *conf, const
 
 static void option_generate_key(fastd_context *ctx, fastd_config *conf) {
 	conf->generate_key = true;
+	conf->show_key = false;
+}
+
+static void option_show_key(fastd_context *ctx, fastd_config *conf) {
+	conf->generate_key = false;
+	conf->show_key = true;
+}
+
+static void option_machine_readable(fastd_context *ctx, fastd_config *conf) {
+	conf->machine_readable = true;
 }
 
 
@@ -580,11 +594,8 @@ void fastd_configure(fastd_context *ctx, fastd_config *conf, int argc, char *con
 		exit_error(ctx, "config error: unknown option `%s'; see --help for usage", argv[i]);
 	}
 
-	if (conf->generate_key) {
+	if (conf->generate_key || conf->show_key)
-		ctx->conf = conf;
+		return;
-		conf->protocol->generate_key(ctx);
-		exit(0);
-	}
 
 	if (conf->mode == MODE_TUN) {
 		if (!conf->peers || conf->peers->next)

src/fastd.c

@@ -625,8 +625,18 @@ int main(int argc, char *argv[]) {
 	fastd_configure(&ctx, &conf, argc, argv);
 	ctx.conf = &conf;
 
+	if (conf.generate_key) {
+		conf.protocol->generate_key(&ctx);
+		exit(0);
+	}
+
 	conf.protocol_config = conf.protocol->init(&ctx);
 
+	if (conf.show_key) {
+		conf.protocol->show_key(&ctx);
+		exit(0);
+	}
+
 	update_time(&ctx);
 
 	init_tuntap(&ctx);

src/fastd.h

@@ -74,6 +74,7 @@ struct _fastd_protocol {
 	void (*free_peer_state)(fastd_context *ctx, fastd_peer *peer);
 
 	void (*generate_key)(fastd_context *ctx);
+	void (*show_key)(fastd_context *ctx);
 };
 
 struct _fastd_method {
@@ -157,7 +158,9 @@ struct _fastd_config {
 	char *on_disestablish;
 	char *on_disestablish_dir;
 
+	bool machine_readable;
 	bool generate_key;
+	bool show_key;
 };
 
 struct _fastd_context {

src/protocol_ec25519_fhmqvc.c

@@ -696,7 +696,8 @@ static void protocol_generate_key(fastd_context *ctx) {
 	ecc_secret_key_256 secret_key;
 	ecc_public_key_256 public_key;
 
-	pr_info(ctx, "Reading 32 bytes from /dev/random...");
+	if (!ctx->conf->machine_readable)
+		pr_info(ctx, "Reading 32 bytes from /dev/random...");
 
 	fastd_random_bytes(ctx, secret_key.s, 32, true);
 	ecc_25519_secret_sanitize(&secret_key, &secret_key);
@@ -705,8 +706,20 @@ static void protocol_generate_key(fastd_context *ctx) {
 	ecc_25519_scalarmult_base(&work, &secret_key);
 	ecc_25519_store(&public_key, &work);
 
-	hexdump("Secret: ", secret_key.s);
+	if (ctx->conf->machine_readable) {
-	hexdump("Public: ", public_key.p);
+		hexdump("", secret_key.s);
+	}
+	else {
+		hexdump("Secret: ", secret_key.s);
+		hexdump("Public: ", public_key.p);
+	}
+}
+
+static void protocol_show_key(fastd_context *ctx) {
+	if (ctx->conf->machine_readable)
+		hexdump("", ctx->conf->protocol_config->public_key.p);
+	else
+		hexdump("Public: ", ctx->conf->protocol_config->public_key.p);
 }
 
 
@@ -725,4 +738,5 @@ const fastd_protocol fastd_protocol_ec25519_fhmqvc = {
 	.free_peer_state = protocol_free_peer_state,
 
 	.generate_key = protocol_generate_key,
+	.show_key = protocol_show_key,
 };