From 64be95a57f4e8596a3b0023579a5778865b30b9f Mon Sep 17 00:00:00 2001 From: TapTap Date: Thu, 16 Jul 2026 16:56:33 +0200 Subject: [PATCH] Fix TLS code review issues: SSL cleanup, TLS 1.2 min, CA verify, deprecation guards, server --help, port validation, __thread io_ssl, shared accept loop --- src/client/client_cli.c | 11 +++- src/client/client_send.c | 10 ++-- src/server/server.c | 35 ++++++++++- src/shared/config.c | 6 ++ src/shared/config.h | 1 + src/shared/protocol.c | 2 +- src/shared/transport_tcp.c | 61 ++++++++++++++----- src/shared/transport_tcp.h | 2 + src/shared/transport_tls.c | 118 ++++++++++++++++++------------------- src/shared/transport_tls.h | 8 ++- 10 files changed, 167 insertions(+), 87 deletions(-) diff --git a/src/client/client_cli.c b/src/client/client_cli.c index 359f86b..fca12b3 100644 --- a/src/client/client_cli.c +++ b/src/client/client_cli.c @@ -2,6 +2,7 @@ #include "config.h" #include "log.h" #include "protocol.h" +#include "transport_tls.h" #include "utils.h" #include #include @@ -49,7 +50,7 @@ static void print_usage(void) { printf(" --tls Enable TLS encryption\n"); printf(" --cert TLS certificate file (PEM)\n"); printf(" --key TLS private key file (PEM)\n"); - printf(" --ca CA certificate for verification (PEM)\n"); + printf(" --ca TLS CA certificate file (PEM)\n"); printf(" --help Show this help\n"); } @@ -217,6 +218,14 @@ int main(int argc, char *argv[]) { return 1; } + if (config->use_tls) { + if (!config->tls_cert || !config->tls_key) { + fprintf(stderr, "Error: --tls requires --cert and --key\n"); + return 1; + } + tls_global_init(); + } + if (config->use_multithreading) return send_files_multithreaded(config); return send_files(config); diff --git a/src/client/client_send.c b/src/client/client_send.c index e263c03..4ab591f 100644 --- a/src/client/client_send.c +++ b/src/client/client_send.c @@ -59,11 +59,11 @@ static int send_chunks_multithreaded(void *pipeline_context) { } client = client_connect_ssh(context->config->ssh_destination, context->config->ssh_port); } else if (context->config->use_tls) { - tls_global_init(); client = client_create(); if (!client || !client_connect_tls(client, server_host, server_port, - context->config->tls_cert, - context->config->tls_key)) { + context->config->tls_cert, + context->config->tls_key, + context->config->tls_ca)) { if (client) client_delete(client); fprintf(stderr, "Error: could not connect to server via TLS\n"); return thrd_error; @@ -213,10 +213,10 @@ int send_files(Config *config) { client = client_connect_ssh(config->ssh_destination, config->ssh_port); if (!client) return 1; } else if (config->use_tls) { - tls_global_init(); client = client_create(); if (!client || !client_connect_tls(client, server_host, server_port, - config->tls_cert, config->tls_key)) { + config->tls_cert, config->tls_key, + config->tls_ca)) { if (client) client_delete(client); fprintf(stderr, "Error: could not connect to server via TLS\n"); return 1; diff --git a/src/server/server.c b/src/server/server.c index 94123fb..4d56917 100644 --- a/src/server/server.c +++ b/src/server/server.c @@ -153,15 +153,34 @@ static void cleanup(int sig) { _exit(0); } +static void print_server_usage(void) { + printf("FastSync Server\n"); + printf("Usage: fastsync-server [options]\n"); + printf("\n"); + printf("Options:\n"); + printf(" --stdio Run in stdio mode (SSH transport)\n"); + printf(" -p TCP port (default: 8080, range: 1-65535)\n"); + printf(" --tls Enable TLS encryption\n"); + printf(" --cert TLS certificate file (PEM)\n"); + printf(" --key TLS private key file (PEM)\n"); + printf(" --ca TLS CA certificate file (PEM)\n"); + printf(" -v, --verbose Enable debug logging\n"); + printf(" --help Show this help\n"); +} + int main(int argc, char *argv[]) { bool use_tls = false; char *tls_cert = NULL; char *tls_key = NULL; + char *tls_ca = NULL; int port = 8080; signal(SIGPIPE, SIG_IGN); for (int i = 1; i < argc; i++) { - if (strcmp(argv[i], "--stdio") == 0) { + if (strcmp(argv[i], "--help") == 0) { + print_server_usage(); + return 0; + } else if (strcmp(argv[i], "--stdio") == 0) { io_set_fds(STDIN_FILENO, STDOUT_FILENO); handler(STDIN_FILENO); return 0; @@ -173,10 +192,22 @@ int main(int argc, char *argv[]) { tls_cert = argv[++i]; } else if (strcmp(argv[i], "--key") == 0 && i + 1 < argc) { tls_key = argv[++i]; + } else if (strcmp(argv[i], "--ca") == 0 && i + 1 < argc) { + tls_ca = argv[++i]; } else if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) { port = atoi(argv[++i]); + } else if (argv[i][0] == '-') { + fprintf(stderr, "Unknown option: %s\n", argv[i]); + print_server_usage(); + return 1; } } + + if (port < 1 || port > 65535) { + fprintf(stderr, "Error: port must be between 1 and 65535\n"); + return 1; + } + signal(SIGINT, cleanup); signal(SIGTERM, cleanup); g_server = server_create(port); @@ -191,7 +222,7 @@ int main(int argc, char *argv[]) { return 1; } tls_global_init(); - if (!server_create_tls(g_server, tls_cert, tls_key)) { + if (!server_create_tls(g_server, tls_cert, tls_key, tls_ca)) { log_message(LOG_LEVEL_ERROR, "Failed to set up TLS"); server_delete(&g_server); return 1; diff --git a/src/shared/config.c b/src/shared/config.c index df2235d..0679e3c 100644 --- a/src/shared/config.c +++ b/src/shared/config.c @@ -41,6 +41,7 @@ Config *config_create(char *version, char *send_directory, config->use_tls = false; config->tls_cert = NULL; config->tls_key = NULL; + config->tls_ca = NULL; return config; } @@ -78,6 +79,7 @@ void config_delete(Config *config) { free(config->include_patterns); free(config->tls_cert); free(config->tls_key); + free(config->tls_ca); free(config); } @@ -150,6 +152,10 @@ Config *config_receive(int file_descriptor) { config->include_count = 0; config->max_size = 0; config->min_size = 0; + config->use_tls = false; + config->tls_cert = NULL; + config->tls_key = NULL; + config->tls_ca = NULL; if (!send_status(file_descriptor, STATUS_OK)) goto error; return config; diff --git a/src/shared/config.h b/src/shared/config.h index a3e93f2..e01857e 100644 --- a/src/shared/config.h +++ b/src/shared/config.h @@ -35,6 +35,7 @@ typedef struct Config { bool use_tls; char *tls_cert; char *tls_key; + char *tls_ca; } Config; #define PROTOCOL_VERSION "1.0.0" diff --git a/src/shared/protocol.c b/src/shared/protocol.c index 0081a20..631c3a6 100644 --- a/src/shared/protocol.c +++ b/src/shared/protocol.c @@ -10,7 +10,7 @@ static __thread int io_read_fd = -1; static __thread int io_write_fd = -1; -static SSL *io_ssl = NULL; +static __thread SSL *io_ssl = NULL; static unsigned long long io_bwlimit = 0; static long long bw_tokens = 0; diff --git a/src/shared/transport_tcp.c b/src/shared/transport_tcp.c index 8e1be80..82e33ba 100644 --- a/src/shared/transport_tcp.c +++ b/src/shared/transport_tcp.c @@ -1,6 +1,7 @@ #include "transport_tcp.h" #include "log.h" #include +#include #include #include #include @@ -52,43 +53,63 @@ Server *server_create(int port) { void server_delete(Server **server) { if (server == NULL || *server == NULL) return; close((*server)->file_descriptor); + if ((*server)->ssl_ctx) { + SSL_CTX_free((*server)->ssl_ctx); + (*server)->ssl_ctx = NULL; + } free(*server); *server = NULL; } -bool server_listen(Server *server, void (*handler)(int file_descriptor)) { - log_message(LOG_LEVEL_INFO, "Start Listening on Port: %d", - server->address.sin_port); +static void accept_loop(Server *server, void (*child_fn)(int, void *), + void *child_ctx, const char *log_fmt) { if (listen(server->file_descriptor, SOMAXCONN) < 0) { perror("Could not listen on port!"); - return false; + return; } - signal(SIGCHLD, SIG_IGN); - while (1) { struct sockaddr_in client_addr; socklen_t client_len = sizeof(client_addr); - int file_descriptor = - accept(server->file_descriptor, (struct sockaddr *)&client_addr, - &client_len); - if (file_descriptor < 0) { + int fd = accept(server->file_descriptor, (struct sockaddr *)&client_addr, + &client_len); + if (fd < 0) { perror("Could not accept the connection"); continue; } - log_message(LOG_LEVEL_INFO, "Received Connection"); + log_message(LOG_LEVEL_INFO, "%s", log_fmt); pid_t pid = fork(); if (pid == 0) { close(server->file_descriptor); - handler(file_descriptor); - close(file_descriptor); + child_fn(fd, child_ctx); + close(fd); _exit(0); } - close(file_descriptor); + close(fd); } +} + +struct plain_ctx { void (*handler)(int); }; + +static void plain_child_fn(int fd, void *ctx) { + ((struct plain_ctx *)ctx)->handler(fd); +} + +bool server_listen(Server *server, void (*handler)(int file_descriptor)) { + log_message(LOG_LEVEL_INFO, "Start Listening on Port: %d", + ntohs(server->address.sin_port)); + struct plain_ctx ctx = {handler}; + accept_loop(server, plain_child_fn, &ctx, "Received Connection"); return true; } +void server_accept_loop(Server *server, void (*child_fn)(int, void *), + void *child_ctx, const char *log_fmt) { + log_message(LOG_LEVEL_INFO, "Start TLS Listening on Port: %d", + ntohs(server->address.sin_port)); + accept_loop(server, child_fn, child_ctx, log_fmt); +} + Client *client_create() { int file_descriptor = socket(AF_INET, SOCK_STREAM, 0); if (file_descriptor < 0) { @@ -127,6 +148,11 @@ bool client_connect(Client *client, char *host, int port) { } void client_disconnect(Client *client) { + if (client->ssl) { + SSL_shutdown(client->ssl); + SSL_free(client->ssl); + client->ssl = NULL; + } close(client->file_descriptor); if (client->ssh_child_pid > 0) { int status; @@ -136,7 +162,10 @@ void client_disconnect(Client *client) { } void client_delete(Client *client) { - if (client == NULL) - return; + if (client == NULL) return; + if (client->ssl_ctx) { + SSL_CTX_free(client->ssl_ctx); + client->ssl_ctx = NULL; + } free(client); } diff --git a/src/shared/transport_tcp.h b/src/shared/transport_tcp.h index c9babfb..b176c18 100644 --- a/src/shared/transport_tcp.h +++ b/src/shared/transport_tcp.h @@ -23,6 +23,8 @@ typedef struct Client { Server *server_create(int port); bool server_listen(Server *server, void (*handler)(int file_descriptor)); +void server_accept_loop(Server *server, void (*child_fn)(int, void *), + void *child_ctx, const char *log_fmt); void server_delete(Server **server); Client *client_create(); bool client_connect(Client *client, char *host, int port); diff --git a/src/shared/transport_tls.c b/src/shared/transport_tls.c index 8a1bfa8..2c9423f 100644 --- a/src/shared/transport_tls.c +++ b/src/shared/transport_tls.c @@ -1,6 +1,7 @@ #include "transport_tls.h" #include "log.h" #include "protocol.h" +#include "transport_tcp.h" #include #include #include @@ -12,52 +13,69 @@ #include #include -static SSL_CTX *g_ssl_ctx = NULL; - bool tls_global_init(void) { +#if OPENSSL_VERSION_NUMBER < 0x10100000L SSL_library_init(); OpenSSL_add_all_algorithms(); SSL_load_error_strings(); +#endif return true; } -void tls_global_cleanup(void) { - if (g_ssl_ctx) { - SSL_CTX_free(g_ssl_ctx); - g_ssl_ctx = NULL; +static void log_ssl_errors(void) { + unsigned long err; + char buf[256]; + while ((err = ERR_get_error()) != 0) { + ERR_error_string_n(err, buf, sizeof(buf)); + log_message(LOG_LEVEL_ERROR, "SSL error: %s", buf); } - EVP_cleanup(); } -static SSL_CTX *create_ssl_ctx(bool is_server, const char *cert, const char *key) { - const SSL_METHOD *method = is_server ? TLS_server_method() : TLS_client_method(); +static SSL_CTX *create_ssl_ctx(bool is_server, const char *cert, + const char *key, const char *ca_path) { + const SSL_METHOD *method = + is_server ? TLS_server_method() : TLS_client_method(); SSL_CTX *ctx = SSL_CTX_new(method); if (!ctx) { log_message(LOG_LEVEL_ERROR, "Unable to create SSL context"); - ERR_print_errors_fp(stderr); + log_ssl_errors(); return NULL; } + SSL_CTX_set_min_proto_version(ctx, TLS1_2_VERSION); + if (cert && key) { if (SSL_CTX_use_certificate_file(ctx, cert, SSL_FILETYPE_PEM) <= 0) { log_message(LOG_LEVEL_ERROR, "Failed to load certificate: %s", cert); - ERR_print_errors_fp(stderr); + log_ssl_errors(); SSL_CTX_free(ctx); return NULL; } if (SSL_CTX_use_PrivateKey_file(ctx, key, SSL_FILETYPE_PEM) <= 0) { log_message(LOG_LEVEL_ERROR, "Failed to load private key: %s", key); - ERR_print_errors_fp(stderr); + log_ssl_errors(); SSL_CTX_free(ctx); return NULL; } if (!SSL_CTX_check_private_key(ctx)) { - log_message(LOG_LEVEL_ERROR, "Private key does not match certificate"); + log_message(LOG_LEVEL_ERROR, + "Private key does not match certificate"); SSL_CTX_free(ctx); return NULL; } } + if (ca_path) { + if (!SSL_CTX_load_verify_locations(ctx, ca_path, NULL)) { + log_message(LOG_LEVEL_ERROR, "Failed to load CA: %s", ca_path); + log_ssl_errors(); + SSL_CTX_free(ctx); + return NULL; + } + SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, NULL); + SSL_CTX_set_verify_depth(ctx, 4); + } + return ctx; } @@ -75,78 +93,60 @@ static SSL *wrap_fd_with_ssl(int fd, SSL_CTX *ctx, bool is_server) { ret = SSL_connect(ssl); if (ret <= 0) { - log_message(LOG_LEVEL_ERROR, "SSL %s failed", is_server ? "accept" : "connect"); - ERR_print_errors_fp(stderr); + log_message(LOG_LEVEL_ERROR, "SSL %s failed", + is_server ? "accept" : "connect"); + log_ssl_errors(); SSL_free(ssl); return NULL; } return ssl; } -bool server_create_tls(Server *server, const char *cert_path, const char *key_path) { - SSL_CTX *ctx = create_ssl_ctx(true, cert_path, key_path); +bool server_create_tls(Server *server, const char *cert_path, + const char *key_path, const char *ca_path) { + SSL_CTX *ctx = create_ssl_ctx(true, cert_path, key_path, ca_path); if (!ctx) return false; server->ssl_ctx = ctx; return true; } +struct tls_child_ctx { + void (*handler)(int); + SSL_CTX *ssl_ctx; +}; + +static void tls_child_fn(int fd, void *arg) { + struct tls_child_ctx *ctx = (struct tls_child_ctx *)arg; + SSL *ssl = wrap_fd_with_ssl(fd, ctx->ssl_ctx, true); + if (!ssl) return; + io_set_ssl(ssl); + ctx->handler(fd); + SSL_shutdown(ssl); + SSL_free(ssl); + io_set_ssl(NULL); +} + bool server_listen_tls(Server *server, void (*handler)(int file_descriptor)) { - log_message(LOG_LEVEL_INFO, "Start TLS Listening on Port: %d", - ntohs(server->address.sin_port)); - if (listen(server->file_descriptor, SOMAXCONN) < 0) { - perror("Could not listen on port!"); - return false; - } - - signal(SIGCHLD, SIG_IGN); - - while (1) { - struct sockaddr_in client_addr; - socklen_t client_len = sizeof(client_addr); - int file_descriptor = - accept(server->file_descriptor, (struct sockaddr *)&client_addr, - &client_len); - if (file_descriptor < 0) { - perror("Could not accept the connection"); - continue; - } - log_message(LOG_LEVEL_INFO, "Received TLS Connection"); - pid_t pid = fork(); - if (pid == 0) { - close(server->file_descriptor); - - SSL *ssl = wrap_fd_with_ssl(file_descriptor, (SSL_CTX *)server->ssl_ctx, true); - if (!ssl) { - close(file_descriptor); - _exit(1); - } - io_set_ssl(ssl); - handler(file_descriptor); - SSL_shutdown(ssl); - SSL_free(ssl); - io_set_ssl(NULL); - close(file_descriptor); - _exit(0); - } - close(file_descriptor); - } + struct tls_child_ctx ctx = {handler, (SSL_CTX *)server->ssl_ctx}; + server_accept_loop(server, tls_child_fn, &ctx, "Received TLS Connection"); return true; } bool client_connect_tls(Client *client, char *host, int port, - const char *cert_path, const char *key_path) { + const char *cert_path, const char *key_path, + const char *ca_path) { client->address.sin_port = htons(port); if (inet_pton(AF_INET, host, &client->address.sin_addr) <= 0) { perror("Could not convert host address!"); return false; } if (connect(client->file_descriptor, (struct sockaddr *)&client->address, - client->address_length) < 0) { + client->address_length) < 0) { perror("Could not connect to Server!"); return false; } - SSL_CTX *ctx = create_ssl_ctx(false, cert_path, key_path); + SSL_CTX *ctx = create_ssl_ctx(false, cert_path, key_path, ca_path); if (!ctx) return false; client->ssl_ctx = ctx; diff --git a/src/shared/transport_tls.h b/src/shared/transport_tls.h index e7180d2..c04333f 100644 --- a/src/shared/transport_tls.h +++ b/src/shared/transport_tls.h @@ -5,10 +5,12 @@ #include bool tls_global_init(void); -void tls_global_cleanup(void); -bool server_create_tls(Server *server, const char *cert_path, const char *key_path); +bool server_create_tls(Server *server, const char *cert_path, + const char *key_path, const char *ca_path); bool server_listen_tls(Server *server, void (*handler)(int file_descriptor)); -bool client_connect_tls(Client *client, char *host, int port, const char *cert_path, const char *key_path); +bool client_connect_tls(Client *client, char *host, int port, + const char *cert_path, const char *key_path, + const char *ca_path); #endif