Implement actual lookup of luksrku entry

Now with a proper UUID the PSK is looked up from the key database.

Makefile

@@ -6,7 +6,7 @@ INSTALL_PREFIX := /usr/local/
 CFLAGS := -Wall -Wextra -Wshadow -Wswitch -Wpointer-arith -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Werror=implicit-function-declaration -Werror=format -Wno-unused-parameter
 CFLAGS += -O3 -std=c11 -pthread -D_POSIX_SOURCE -D_XOPEN_SOURCE=500 -DBUILD_REVISION='"$(BUILD_REVISION)"'
 CFLAGS += `pkg-config --cflags openssl`
-#CFLAGS += -ggdb3 -DDEBUG -fsanitize=address -fsanitize=undefined -fsanitize=leak
+CFLAGS += -ggdb3 -DDEBUG -fsanitize=address -fsanitize=undefined -fsanitize=leak
 PYPGMOPTS := ../Python/pypgmopts/pypgmopts
 
 LDFLAGS := `pkg-config --libs openssl`

keydb.c

@@ -108,6 +108,16 @@ struct host_entry_t *keydb_get_host_by_name(struct keydb_t *keydb, const char *h
 	return (index >= 0) ? &keydb->hosts[index] : NULL;
 }
 
+const struct host_entry_t* keydb_get_host_by_uuid(const struct keydb_t *keydb, const uint8_t uuid[static 16]) {
+	for (unsigned int i = 0; i < keydb->host_count; i++) {
+		const struct host_entry_t *host = &keydb->hosts[i];
+		if (!memcmp(host->host_uuid, uuid, 16)) {
+			return host;
+		}
+	}
+	return NULL;
+}
+
 bool keydb_add_host(struct keydb_t **keydb, const char *host_name) {
 	if (strlen(host_name) > MAX_HOST_NAME_LENGTH - 1) {
 		log_msg(LLVL_ERROR, "Host name \"%s\" exceeds maximum length of %d characters.", host_name, MAX_HOST_NAME_LENGTH - 1);

keydb.h

@@ -59,6 +59,7 @@ struct keydb_t* keydb_export_public(struct host_entry_t *host);
 void keydb_free(struct keydb_t *keydb);
 struct volume_entry_t* keydb_get_volume_by_name(struct host_entry_t *host, const char *devmapper_name);
 struct host_entry_t* keydb_get_host_by_name(struct keydb_t *keydb, const char *host_name);
+const struct host_entry_t* keydb_get_host_by_uuid(const struct keydb_t *keydb, const uint8_t uuid[static 16]);
 bool keydb_add_host(struct keydb_t **keydb, const char *host_name);
 bool keydb_del_host_by_name(struct keydb_t **keydb, const char *host_name);
 bool keydb_rekey_host(struct host_entry_t *host);

server.c

@@ -42,6 +42,7 @@
 #include "server.h"
 #include "luks.h"
 #include "pgmopts.h"
+#include "uuid.h"
 
 static int create_tcp_server_socket(int port) {
 	int s;
@@ -305,22 +306,71 @@ static unsigned int psk_server_callback(SSL *ssl, const char *identity, unsigned
 #endif
 
 static int psk_server_callback(SSL *ssl, const unsigned char *identity, size_t identity_len, SSL_SESSION **sessptr) {
-	fprintf(stderr, "PSK server SSL %p identity %s len %ld sess %p\n", ssl, identity, identity_len, *sessptr);
-	SSL_SESSION *sess = SSL_SESSION_new();
-	SSL_SESSION_set1_master_key(sess, (const unsigned char*)"\x00\x11\x22", 3);
-	const unsigned char tls13_aes128gcmsha256_id[] = { 0x13, 0x01 };
-	const SSL_CIPHER *cipher = SSL_CIPHER_find(ssl, tls13_aes128gcmsha256_id);
-	if (!cipher) {
+	const struct keydb_t *keydb = (const struct keydb_t*)SSL_get_default_passwd_cb_userdata(ssl);
+
+	if (identity_len != ASCII_UUID_CHARACTER_COUNT) {
+		log_msg(LLVL_WARNING, "Received client identity of length %d, cannot be a UUID.", identity_len);
 		return 0;
 	}
-	SSL_SESSION_set_cipher(sess, cipher);
-	SSL_SESSION_set_protocol_version(sess, TLS1_3_VERSION);
+
+	char uuid_str[ASCII_UUID_BUFSIZE];
+	memcpy(uuid_str, identity, ASCII_UUID_CHARACTER_COUNT);
+	uuid_str[ASCII_UUID_CHARACTER_COUNT] = 0;
+	if (!is_valid_uuid(uuid_str)) {
+		log_msg(LLVL_WARNING, "Received client identity of length %d, but not a valid UUID.", identity_len);
+		return 0;
+	}
+
+	uint8_t uuid[16];
+	if (!parse_uuid(uuid, uuid_str)) {
+		log_msg(LLVL_ERROR, "Failed to parse valid UUID.");
+		return 0;
+	}
+
+	const struct host_entry_t *host = keydb_get_host_by_uuid(keydb, uuid);
+	if (!host) {
+		log_msg(LLVL_WARNING, "Client connected with client UUID %s, but not present in key database.", uuid_str);
+		return 0;
+	}
+
+	const uint8_t tls13_aes128gcmsha256_id[] = { 0x13, 0x01 };
+	const SSL_CIPHER *cipher = SSL_CIPHER_find(ssl, tls13_aes128gcmsha256_id);
+	if (!cipher) {
+		log_openssl(LLVL_ERROR, "Unable to look up SSL_CIPHER for TLSv1.3-PSK");
+		return 0;
+	}
+
+	SSL_SESSION *sess = SSL_SESSION_new();
+	if (!sess) {
+		log_openssl(LLVL_ERROR, "Failed to create SSL_SESSION context for client.");
+		return 0;
+	}
+
+	if (!SSL_SESSION_set1_master_key(sess, (const unsigned char*)"\x00\x11\x22", 3)) {
+		log_openssl(LLVL_ERROR, "Failed to set TLSv1.3-PSK master key.");
+		SSL_SESSION_free(sess);
+		return 0;
+	}
+
+	if (!SSL_SESSION_set_cipher(sess, cipher)) {
+		log_openssl(LLVL_ERROR, "Failed to set TLSv1.3-PSK cipher.");
+		SSL_SESSION_free(sess);
+		return 0;
+	}
+
+	if (!SSL_SESSION_set_protocol_version(sess, TLS1_3_VERSION)) {
+		log_openssl(LLVL_ERROR, "Failed to set TLSv1.3-PSK protocol version.");
+		SSL_SESSION_free(sess);
+		return 0;
+	}
+
 	*sessptr = sess;
 	return 1;
 }
 
 struct client_ctx_t {
 	struct generic_tls_ctx_t *gctx;
+	const struct keydb_t *keydb;
 	int fd;
 };
 
@@ -329,11 +379,13 @@ static void *client_handler_thread(void *vctx) {
 
 	SSL *ssl = SSL_new(client->gctx->ctx);
 	SSL_set_fd(ssl, client->fd);
+	SSL_set_default_passwd_cb_userdata(ssl, (void*)client->keydb);
 
 	if (SSL_accept(ssl) <= 0) {
 		ERR_print_errors_fp(stderr);
 	} else {
-		log_msg(LLVL_DEBUG, "Client connected, waiting for data...");
+		log_msg(LLVL_DEBUG, "Client connected, sending their data...");
+		/*
 		while (true) {
 			struct msg_t msg;
 			int rxlen = SSL_read(ssl, &msg, sizeof(msg));
@@ -342,6 +394,7 @@ static void *client_handler_thread(void *vctx) {
 				break;
 			}
 		}
+		*/
 		fprintf(stderr, "done\n");
 	}
 
@@ -353,6 +406,19 @@ static void *client_handler_thread(void *vctx) {
 }
 
 bool keyserver_start(const struct pgmopts_server_t *opts) {
+	/* Load key database first */
+	struct keydb_t* keydb = keydb_read(opts->filename);
+	if (!keydb) {
+		log_msg(LLVL_FATAL, "Failed to load key database: %s", opts->filename);
+		return false;
+	}
+
+	if (!keydb->server_database) {
+		log_msg(LLVL_FATAL, "Not a server key database: %s", opts->filename);
+		keydb_free(keydb);
+		return false;
+	}
+
 	struct generic_tls_ctx_t gctx;
 	if (!create_generic_tls_context(&gctx, true)) {
 		log_msg(LLVL_FATAL, "Failed to create OpenSSL server context.");
@@ -361,9 +427,6 @@ bool keyserver_start(const struct pgmopts_server_t *opts) {
 
 	SSL_CTX_set_psk_find_session_callback(gctx.ctx, psk_server_callback);
 
-    if (!SSL_CTX_use_psk_identity_hint(gctx.ctx, "watwatwat")) {
-	}
-
 	int tcp_sock = create_tcp_server_socket(opts->port);
 	if (tcp_sock == -1) {
 		log_msg(LLVL_ERROR, "Cannot start server without server socket.");
@@ -391,6 +454,7 @@ bool keyserver_start(const struct pgmopts_server_t *opts) {
 			return false;
 		}
 		client_ctx->gctx = &gctx;
+		client_ctx->keydb = keydb;
 		client_ctx->fd = client;
 
 		pthread_t thread;

uuid.h

@@ -27,8 +27,10 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+#define ASCII_UUID_CHARACTER_COUNT	36
+
 /* Already includes zero termination */
-#define ASCII_UUID_BUFSIZE			37
+#define ASCII_UUID_BUFSIZE			(ASCII_UUID_CHARACTER_COUNT + 1)
 
 /*************** AUTO GENERATED SECTION FOLLOWS ***************/
 bool is_valid_uuid(const char *ascii_uuid);