diff --git a/CMakeLists.txt b/CMakeLists.txt index 6555105..a317839 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -19,6 +19,8 @@ if(NOT ZSTD_LIBRARY) message(FATAL_ERROR "zstd library not found. Ensure it is in your nix-shell!") endif() +find_package(OpenSSL REQUIRED) + file(GLOB SHARED_SRCS "src/shared/*.c") file(GLOB SERVER_SRCS "src/server/*.c") file(GLOB CLIENT_SRCS "src/client/*.c") @@ -26,13 +28,13 @@ file(GLOB TEST_SRCS "tests/*.c") add_executable(server ${SERVER_SRCS} ${SHARED_SRCS}) target_include_directories(server PRIVATE src/shared src/server src/client) -target_link_libraries(server PRIVATE Threads::Threads ${ZSTD_LIBRARY}) +target_link_libraries(server PRIVATE Threads::Threads ${ZSTD_LIBRARY} OpenSSL::SSL OpenSSL::Crypto) add_executable(client ${CLIENT_SRCS} ${SHARED_SRCS}) target_include_directories(client PRIVATE src/shared src/server src/client) -target_link_libraries(client PRIVATE Threads::Threads ${ZSTD_LIBRARY}) +target_link_libraries(client PRIVATE Threads::Threads ${ZSTD_LIBRARY} OpenSSL::SSL OpenSSL::Crypto) add_executable(tests ${TEST_SRCS} ${SHARED_SRCS} src/client/scanner.c) target_include_directories(tests PRIVATE tests src/shared src/server src/client) -target_link_libraries(tests PRIVATE Threads::Threads ${ZSTD_LIBRARY}) +target_link_libraries(tests PRIVATE Threads::Threads ${ZSTD_LIBRARY} OpenSSL::SSL OpenSSL::Crypto) diff --git a/shell.nix b/shell.nix index 1259d7b..2d4d25d 100644 --- a/shell.nix +++ b/shell.nix @@ -13,6 +13,7 @@ pkgs.mkShell { buildInputs = with pkgs; [ zstd + openssl ]; NIX_ENFORCE_PURITY = 0; diff --git a/src/client/client_cli.c b/src/client/client_cli.c index 44fca4b..359f86b 100644 --- a/src/client/client_cli.c +++ b/src/client/client_cli.c @@ -46,6 +46,10 @@ static void print_usage(void) { printf(" --server-host Server IP address (default: 127.0.0.1)\n"); printf(" --server-port Server port (default: 8080)\n"); printf(" --bwlimit Bandwidth limit in kilobytes per second\n"); + 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(" --help Show this help\n"); } @@ -151,6 +155,17 @@ int main(int argc, char *argv[]) { unsigned long long val = strtoull(argv[++i], NULL, 10); if (val > 0) config->chunk_size = val; + } else if (strcmp(argv[i], "--tls") == 0) { + config->use_tls = true; + } else if (strcmp(argv[i], "--cert") == 0 && i + 1 < argc) { + free(config->tls_cert); + config->tls_cert = str_dup(argv[++i]); + } else if (strcmp(argv[i], "--key") == 0 && i + 1 < argc) { + free(config->tls_key); + config->tls_key = str_dup(argv[++i]); + } else if (strcmp(argv[i], "--ca") == 0 && i + 1 < argc) { + free(config->tls_ca); + config->tls_ca = str_dup(argv[++i]); } else if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--verbose") == 0) { set_log_level(LOG_LEVEL_DEBUG); } else if (argv[i][0] == '-') { diff --git a/src/client/client_send.c b/src/client/client_send.c index 4c70204..e263c03 100644 --- a/src/client/client_send.c +++ b/src/client/client_send.c @@ -11,6 +11,7 @@ #include "scanner.h" #include "transport_tcp.h" #include "transport_ssh.h" +#include "transport_tls.h" #include "utils.h" #include #include @@ -57,6 +58,16 @@ static int send_chunks_multithreaded(void *pipeline_context) { return 1; } 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)) { + if (client) client_delete(client); + fprintf(stderr, "Error: could not connect to server via TLS\n"); + return thrd_error; + } } else { client = client_create(); if (!client || !client_connect(client, server_host, server_port)) { @@ -201,6 +212,15 @@ 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)) { + if (client) client_delete(client); + fprintf(stderr, "Error: could not connect to server via TLS\n"); + return 1; + } } else { client = client_create(); if (!client || !client_connect(client, server_host, server_port)) { diff --git a/src/server/server.c b/src/server/server.c index a7edce5..94123fb 100644 --- a/src/server/server.c +++ b/src/server/server.c @@ -10,6 +10,7 @@ #include "protocol.h" #include "queue.h" #include "transport_tcp.h" +#include "transport_tls.h" #include "unistd.h" #include "utils.h" #include @@ -153,6 +154,11 @@ static void cleanup(int sig) { } int main(int argc, char *argv[]) { + bool use_tls = false; + char *tls_cert = NULL; + char *tls_key = NULL; + int port = 8080; + signal(SIGPIPE, SIG_IGN); for (int i = 1; i < argc; i++) { if (strcmp(argv[i], "--stdio") == 0) { @@ -161,15 +167,38 @@ int main(int argc, char *argv[]) { return 0; } else if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--verbose") == 0) { set_log_level(LOG_LEVEL_DEBUG); + } else if (strcmp(argv[i], "--tls") == 0) { + use_tls = true; + } else if (strcmp(argv[i], "--cert") == 0 && i + 1 < argc) { + tls_cert = argv[++i]; + } else if (strcmp(argv[i], "--key") == 0 && i + 1 < argc) { + tls_key = argv[++i]; + } else if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) { + port = atoi(argv[++i]); } } signal(SIGINT, cleanup); signal(SIGTERM, cleanup); - g_server = server_create(8080); + g_server = server_create(port); if (g_server == NULL) { log_message(LOG_LEVEL_ERROR, "Failed to create server"); return 1; } - server_listen(g_server, handler); + if (use_tls) { + if (!tls_cert || !tls_key) { + fprintf(stderr, "Error: --tls requires --cert and --key\n"); + server_delete(&g_server); + return 1; + } + tls_global_init(); + if (!server_create_tls(g_server, tls_cert, tls_key)) { + log_message(LOG_LEVEL_ERROR, "Failed to set up TLS"); + server_delete(&g_server); + return 1; + } + server_listen_tls(g_server, handler); + } else { + server_listen(g_server, handler); + } return 0; } diff --git a/src/shared/config.c b/src/shared/config.c index a22e489..df2235d 100644 --- a/src/shared/config.c +++ b/src/shared/config.c @@ -38,6 +38,9 @@ Config *config_create(char *version, char *send_directory, config->include_count = 0; config->max_size = 0; config->min_size = 0; + config->use_tls = false; + config->tls_cert = NULL; + config->tls_key = NULL; return config; } @@ -73,6 +76,8 @@ void config_delete(Config *config) { for (int i = 0; i < config->include_count; i++) free(config->include_patterns[i]); free(config->include_patterns); + free(config->tls_cert); + free(config->tls_key); free(config); } diff --git a/src/shared/config.h b/src/shared/config.h index b08f733..a3e93f2 100644 --- a/src/shared/config.h +++ b/src/shared/config.h @@ -32,6 +32,9 @@ typedef struct Config { int include_count; unsigned long long max_size; unsigned long long min_size; + bool use_tls; + char *tls_cert; + char *tls_key; } Config; #define PROTOCOL_VERSION "1.0.0" diff --git a/src/shared/protocol.c b/src/shared/protocol.c index 4f2b82a..0081a20 100644 --- a/src/shared/protocol.c +++ b/src/shared/protocol.c @@ -1,6 +1,7 @@ #include "protocol.h" #include "log.h" #include +#include #include #include #include @@ -9,6 +10,7 @@ static __thread int io_read_fd = -1; static __thread int io_write_fd = -1; +static SSL *io_ssl = NULL; static unsigned long long io_bwlimit = 0; static long long bw_tokens = 0; @@ -54,6 +56,10 @@ static void bw_throttle(size_t bytes_written) { } } +void io_set_ssl(SSL *ssl) { + io_ssl = ssl; +} + static int io_fd(int dir_fd, int file_descriptor) { return (dir_fd != -1) ? dir_fd : file_descriptor; } @@ -66,8 +72,11 @@ bool send_n_data(int file_descriptor, void *data, size_t data_size) { size_t chunk = data_size - total_bytes_send; if (io_bwlimit > 0 && chunk > 65536) chunk = 65536; - ssize_t bytes_send = - write(fd, (char *)data + total_bytes_send, chunk); + ssize_t bytes_send; + if (io_ssl) + bytes_send = SSL_write(io_ssl, (char *)data + total_bytes_send, chunk); + else + bytes_send = write(fd, (char *)data + total_bytes_send, chunk); if (bytes_send <= 0) { log_message(LOG_LEVEL_ERROR, "Could not send data"); return false; @@ -84,8 +93,13 @@ bool receive_n_data(int file_descriptor, void *data, size_t data_size) { int fd = io_fd(io_read_fd, file_descriptor); size_t total_bytes_received = 0; while (total_bytes_received < data_size) { - ssize_t bytes_received = - read(fd, (char *)data + total_bytes_received, data_size - total_bytes_received); + ssize_t bytes_received; + if (io_ssl) + bytes_received = SSL_read(io_ssl, (char *)data + total_bytes_received, + data_size - total_bytes_received); + else + bytes_received = read(fd, (char *)data + total_bytes_received, + data_size - total_bytes_received); if (bytes_received <= 0) { if (bytes_received == 0) log_message(LOG_LEVEL_ERROR, "Connection closed while receiving data"); diff --git a/src/shared/protocol.h b/src/shared/protocol.h index 1880d24..23b6903 100644 --- a/src/shared/protocol.h +++ b/src/shared/protocol.h @@ -10,6 +10,8 @@ enum NET_STATUS { STATUS_OK, STATUS_ERROR, STATUS_FINISHED, STATUS_NEXT, STATUS_ void io_set_fds(int read_fd, int write_fd); void io_set_bwlimit(unsigned long long bytes_per_sec); +typedef struct ssl_st SSL; +void io_set_ssl(SSL *ssl); bool send_n_data(int file_descriptor, void *data, size_t data_size); bool receive_n_data(int file_descriptor, void *data, size_t data_size); diff --git a/src/shared/transport_tcp.c b/src/shared/transport_tcp.c index 18bcaf4..8e1be80 100644 --- a/src/shared/transport_tcp.c +++ b/src/shared/transport_tcp.c @@ -36,6 +36,7 @@ Server *server_create(int port) { server->address.sin_addr.s_addr = INADDR_ANY; server->address.sin_port = htons(port); server->address_length = sizeof(server->address); + server->ssl_ctx = NULL; if (bind(server->file_descriptor, (struct sockaddr *)&server->address, server->address_length) < 0) { @@ -104,6 +105,8 @@ Client *client_create() { client->address.sin_family = AF_INET; client->address_length = sizeof(client->address); client->ssh_child_pid = -1; + client->ssl = NULL; + client->ssl_ctx = NULL; return client; } diff --git a/src/shared/transport_tcp.h b/src/shared/transport_tcp.h index 6479d2f..c9babfb 100644 --- a/src/shared/transport_tcp.h +++ b/src/shared/transport_tcp.h @@ -9,6 +9,7 @@ typedef struct Server { struct sockaddr_in address; unsigned int address_length; int file_descriptor; + void *ssl_ctx; } Server; typedef struct Client { @@ -16,6 +17,8 @@ typedef struct Client { unsigned int address_length; int file_descriptor; pid_t ssh_child_pid; + void *ssl; + void *ssl_ctx; } Client; Server *server_create(int port); diff --git a/src/shared/transport_tls.c b/src/shared/transport_tls.c new file mode 100644 index 0000000..8a1bfa8 --- /dev/null +++ b/src/shared/transport_tls.c @@ -0,0 +1,162 @@ +#include "transport_tls.h" +#include "log.h" +#include "protocol.h" +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static SSL_CTX *g_ssl_ctx = NULL; + +bool tls_global_init(void) { + SSL_library_init(); + OpenSSL_add_all_algorithms(); + SSL_load_error_strings(); + return true; +} + +void tls_global_cleanup(void) { + if (g_ssl_ctx) { + SSL_CTX_free(g_ssl_ctx); + g_ssl_ctx = NULL; + } + 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(); + SSL_CTX *ctx = SSL_CTX_new(method); + if (!ctx) { + log_message(LOG_LEVEL_ERROR, "Unable to create SSL context"); + ERR_print_errors_fp(stderr); + return NULL; + } + + 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); + 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); + SSL_CTX_free(ctx); + return NULL; + } + if (!SSL_CTX_check_private_key(ctx)) { + log_message(LOG_LEVEL_ERROR, "Private key does not match certificate"); + SSL_CTX_free(ctx); + return NULL; + } + } + + return ctx; +} + +static SSL *wrap_fd_with_ssl(int fd, SSL_CTX *ctx, bool is_server) { + SSL *ssl = SSL_new(ctx); + if (!ssl) { + log_message(LOG_LEVEL_ERROR, "Failed to create SSL object"); + return NULL; + } + SSL_set_fd(ssl, fd); + int ret; + if (is_server) + ret = SSL_accept(ssl); + else + ret = SSL_connect(ssl); + + if (ret <= 0) { + log_message(LOG_LEVEL_ERROR, "SSL %s failed", is_server ? "accept" : "connect"); + ERR_print_errors_fp(stderr); + 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); + if (!ctx) return false; + server->ssl_ctx = ctx; + return true; +} + +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); + } + return true; +} + +bool client_connect_tls(Client *client, char *host, int port, + const char *cert_path, const char *key_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) { + perror("Could not connect to Server!"); + return false; + } + + SSL_CTX *ctx = create_ssl_ctx(false, cert_path, key_path); + if (!ctx) return false; + client->ssl_ctx = ctx; + + SSL *ssl = wrap_fd_with_ssl(client->file_descriptor, ctx, false); + if (!ssl) { + SSL_CTX_free(ctx); + client->ssl_ctx = NULL; + return false; + } + client->ssl = ssl; + io_set_ssl(ssl); + return true; +} diff --git a/src/shared/transport_tls.h b/src/shared/transport_tls.h new file mode 100644 index 0000000..e7180d2 --- /dev/null +++ b/src/shared/transport_tls.h @@ -0,0 +1,14 @@ +#ifndef TRANSPORT_TLS_H +#define TRANSPORT_TLS_H + +#include "transport_tcp.h" +#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_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); + +#endif