diff options
Diffstat (limited to '')
| -rw-r--r-- | libnetdata/socket/security.c | 385 |
1 files changed, 385 insertions, 0 deletions
diff --git a/libnetdata/socket/security.c b/libnetdata/socket/security.c new file mode 100644 index 0000000..53366c4 --- /dev/null +++ b/libnetdata/socket/security.c @@ -0,0 +1,385 @@ +#include "../libnetdata.h" + +#ifdef ENABLE_HTTPS + +SSL_CTX *netdata_exporting_ctx=NULL; +SSL_CTX *netdata_client_ctx=NULL; +SSL_CTX *netdata_srv_ctx=NULL; +const char *security_key=NULL; +const char *security_cert=NULL; +const char *tls_version=NULL; +const char *tls_ciphers=NULL; +int netdata_validate_server = NETDATA_SSL_VALID_CERTIFICATE; + +/** + * Info Callback + * + * Function used as callback for the OpenSSL Library + * + * @param ssl a pointer to the SSL structure of the client + * @param where the variable with the flags set. + * @param ret the return of the caller + */ +static void security_info_callback(const SSL *ssl, int where, int ret __maybe_unused) { + (void)ssl; + if (where & SSL_CB_ALERT) { + debug(D_WEB_CLIENT,"SSL INFO CALLBACK %s %s", SSL_alert_type_string(ret), SSL_alert_desc_string_long(ret)); + } +} + +/** + * OpenSSL Library + * + * Starts the openssl library for the Netdata. + */ +void security_openssl_library() +{ +#if OPENSSL_VERSION_NUMBER < OPENSSL_VERSION_110 +# if (SSLEAY_VERSION_NUMBER >= OPENSSL_VERSION_097) + OPENSSL_config(NULL); +# endif + + SSL_load_error_strings(); + + SSL_library_init(); +#else + if (OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL) != 1) { + error("SSL library cannot be initialized."); + } +#endif +} + +#if OPENSSL_VERSION_NUMBER >= OPENSSL_VERSION_110 +/** + * TLS version + * + * Returns the TLS version depending of the user input. + * + * @param lversion is the user input. + * + * @return it returns the version number. + */ +int tls_select_version(const char *lversion) { + if (!strcmp(lversion, "1") || !strcmp(lversion, "1.0")) + return TLS1_VERSION; + else if (!strcmp(lversion, "1.1")) + return TLS1_1_VERSION; + else if (!strcmp(lversion, "1.2")) + return TLS1_2_VERSION; +#if defined(TLS1_3_VERSION) + else if (!strcmp(lversion, "1.3")) + return TLS1_3_VERSION; +#endif + +#if defined(TLS_MAX_VERSION) + return TLS_MAX_VERSION; +#else + return TLS1_2_VERSION; +#endif +} +#endif + +/** + * OpenSSL common options + * + * Clients and SERVER have common options, this function is responsible to set them in the context. + * + * @param ctx the initialized SSL context. + * @param side 0 means server, and 1 client. + */ +void security_openssl_common_options(SSL_CTX *ctx, int side) { +#if OPENSSL_VERSION_NUMBER >= OPENSSL_VERSION_110 + if (!side) { + int version = tls_select_version(tls_version) ; +#endif +#if OPENSSL_VERSION_NUMBER < OPENSSL_VERSION_110 + SSL_CTX_set_options (ctx,SSL_OP_NO_SSLv2|SSL_OP_NO_SSLv3|SSL_OP_NO_COMPRESSION); +#else + SSL_CTX_set_min_proto_version(ctx, TLS1_VERSION); + SSL_CTX_set_max_proto_version(ctx, version); + + if(tls_ciphers && strcmp(tls_ciphers, "none") != 0) { + if (!SSL_CTX_set_cipher_list(ctx, tls_ciphers)) { + error("SSL error. cannot set the cipher list"); + } + } + } +#endif + + SSL_CTX_set_mode(ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER); +} + +/** + * Initialize Openssl Client + * + * Starts the client context with TLS 1.2. + * + * @return It returns the context on success or NULL otherwise + */ +SSL_CTX * security_initialize_openssl_client() { + SSL_CTX *ctx; +#if OPENSSL_VERSION_NUMBER < OPENSSL_VERSION_110 + ctx = SSL_CTX_new(SSLv23_client_method()); +#else + ctx = SSL_CTX_new(TLS_client_method()); +#endif + if(ctx) { +#if OPENSSL_VERSION_NUMBER < OPENSSL_VERSION_110 + SSL_CTX_set_options (ctx,SSL_OP_NO_SSLv2|SSL_OP_NO_SSLv3|SSL_OP_NO_COMPRESSION); +#else + SSL_CTX_set_min_proto_version(ctx, TLS1_VERSION); +# if defined(TLS_MAX_VERSION) + SSL_CTX_set_max_proto_version(ctx, TLS_MAX_VERSION); +# elif defined(TLS1_3_VERSION) + SSL_CTX_set_max_proto_version(ctx, TLS1_3_VERSION); +# elif defined(TLS1_2_VERSION) + SSL_CTX_set_max_proto_version(ctx, TLS1_2_VERSION); +# endif +#endif + } + + return ctx; +} + +/** + * Initialize OpenSSL server + * + * Starts the server context with TLS 1.2 and load the certificate. + * + * @return It returns the context on success or NULL otherwise + */ +static SSL_CTX * security_initialize_openssl_server() { + SSL_CTX *ctx; + char lerror[512]; + static int netdata_id_context = 1; + + //TO DO: Confirm the necessity to check return for other OPENSSL function +#if OPENSSL_VERSION_NUMBER < OPENSSL_VERSION_110 + ctx = SSL_CTX_new(SSLv23_server_method()); + if (!ctx) { + error("Cannot create a new SSL context, netdata won't encrypt communication"); + return NULL; + } + + SSL_CTX_use_certificate_file(ctx, security_cert, SSL_FILETYPE_PEM); +#else + ctx = SSL_CTX_new(TLS_server_method()); + if (!ctx) { + error("Cannot create a new SSL context, netdata won't encrypt communication"); + return NULL; + } + + SSL_CTX_use_certificate_chain_file(ctx, security_cert); +#endif + security_openssl_common_options(ctx, 0); + + SSL_CTX_use_PrivateKey_file(ctx,security_key,SSL_FILETYPE_PEM); + + if (!SSL_CTX_check_private_key(ctx)) { + ERR_error_string_n(ERR_get_error(),lerror,sizeof(lerror)); + error("SSL cannot check the private key: %s",lerror); + SSL_CTX_free(ctx); + return NULL; + } + + SSL_CTX_set_session_id_context(ctx,(void*)&netdata_id_context,(unsigned int)sizeof(netdata_id_context)); + SSL_CTX_set_info_callback(ctx,security_info_callback); + +#if (OPENSSL_VERSION_NUMBER < OPENSSL_VERSION_095) + SSL_CTX_set_verify_depth(ctx,1); +#endif + debug(D_WEB_CLIENT,"SSL GLOBAL CONTEXT STARTED\n"); + + return ctx; +} + +/** + * Start SSL + * + * Call the correct function to start the SSL context. + * + * @param selector informs the context that must be initialized, the following list has the valid values: + * NETDATA_SSL_CONTEXT_SERVER - the server context + * NETDATA_SSL_CONTEXT_STREAMING - Starts the streaming context. + * NETDATA_SSL_CONTEXT_EXPORTING - Starts the OpenTSDB contextv + */ +void security_start_ssl(int selector) { + switch (selector) { + case NETDATA_SSL_CONTEXT_SERVER: { + struct stat statbuf; + if (stat(security_key, &statbuf) || stat(security_cert, &statbuf)) { + info("To use encryption it is necessary to set \"ssl certificate\" and \"ssl key\" in [web] !\n"); + return; + } + + netdata_srv_ctx = security_initialize_openssl_server(); + break; + } + case NETDATA_SSL_CONTEXT_STREAMING: { + netdata_client_ctx = security_initialize_openssl_client(); + //This is necessary for the stream, because it is working sometimes with nonblock socket. + //It returns the bitmask afte to change, there is not any description of errors in the documentation + SSL_CTX_set_mode(netdata_client_ctx, SSL_MODE_ENABLE_PARTIAL_WRITE |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER |SSL_MODE_AUTO_RETRY); + break; + } + case NETDATA_SSL_CONTEXT_EXPORTING: { + netdata_exporting_ctx = security_initialize_openssl_client(); + break; + } + } +} + +/** + * Clean Open SSL + * + * Clean all the allocated contexts from netdata. + */ +void security_clean_openssl() +{ + if (netdata_srv_ctx) { + SSL_CTX_free(netdata_srv_ctx); + } + + if (netdata_client_ctx) { + SSL_CTX_free(netdata_client_ctx); + } + + if (netdata_exporting_ctx) { + SSL_CTX_free(netdata_exporting_ctx); + } + +#if OPENSSL_VERSION_NUMBER < OPENSSL_VERSION_110 + ERR_free_strings(); +#endif +} + +/** + * Process accept + * + * Process the SSL handshake with the client case it is necessary. + * + * @param ssl is a pointer for the SSL structure + * @param msg is a copy of the first 8 bytes of the initial message received + * + * @return it returns 0 case it performs the handshake, 8 case it is clean connection + * and another integer power of 2 otherwise. + */ +int security_process_accept(SSL *ssl,int msg) { + int sock = SSL_get_fd(ssl); + int test; + if (msg > 0x17) + { + return NETDATA_SSL_NO_HANDSHAKE; + } + + ERR_clear_error(); + if ((test = SSL_accept(ssl)) <= 0) { + int sslerrno = SSL_get_error(ssl, test); + switch(sslerrno) { + case SSL_ERROR_WANT_READ: + { + error("SSL handshake did not finish and it wanna read on socket %d!", sock); + return NETDATA_SSL_WANT_READ; + } + case SSL_ERROR_WANT_WRITE: + { + error("SSL handshake did not finish and it wanna read on socket %d!", sock); + return NETDATA_SSL_WANT_WRITE; + } + case SSL_ERROR_NONE: + case SSL_ERROR_SSL: + case SSL_ERROR_SYSCALL: + default: + { + u_long err; + char buf[256]; + int counter = 0; + while ((err = ERR_get_error()) != 0) { + ERR_error_string_n(err, buf, sizeof(buf)); + info("%d SSL Handshake error (%s) on socket %d ", counter++, ERR_error_string((long)SSL_get_error(ssl, test), NULL), sock); + } + return NETDATA_SSL_NO_HANDSHAKE; + } + } + } + + if (SSL_is_init_finished(ssl)) + { + debug(D_WEB_CLIENT_ACCESS,"SSL Handshake finished %s errno %d on socket fd %d", ERR_error_string((long)SSL_get_error(ssl, test), NULL), errno, sock); + } + + return NETDATA_SSL_HANDSHAKE_COMPLETE; +} + +/** + * Test Certificate + * + * Check the certificate of Netdata parent + * + * @param ssl is the connection structure + * + * @return It returns 0 on success and -1 otherwise + */ +int security_test_certificate(SSL *ssl) { + X509* cert = SSL_get_peer_certificate(ssl); + int ret; + long status; + if (!cert) { + return -1; + } + + status = SSL_get_verify_result(ssl); + if((X509_V_OK != status)) + { + char error[512]; + ERR_error_string_n(ERR_get_error(), error, sizeof(error)); + error("SSL RFC4158 check: We have a invalid certificate, the tests result with %ld and message %s", status, error); + ret = -1; + } else { + ret = 0; + } + + return ret; +} + +/** + * Location for context + * + * Case the user give us a directory with the certificates available and + * the Netdata parent certificate, we use this function to validate the certificate. + * + * @param ctx the context where the path will be set. + * @param file the file with Netdata parent certificate. + * @param path the directory where the certificates are stored. + * + * @return It returns 0 on success and -1 otherwise. + */ +int security_location_for_context(SSL_CTX *ctx, char *file, char *path) { + struct stat statbuf; + if (stat(file, &statbuf)) { + info("Netdata does not have the parent's SSL certificate, so it will use the default OpenSSL configuration to validate certificates!"); + return 0; + } + + ERR_clear_error(); + u_long err; + char buf[256]; + if(!SSL_CTX_load_verify_locations(ctx, file, path)) { + goto slfc; + } + + if(!SSL_CTX_set_default_verify_paths(ctx)) { + goto slfc; + } + + return 0; + +slfc: + while ((err = ERR_get_error()) != 0) { + ERR_error_string_n(err, buf, sizeof(buf)); + error("Cannot set the directory for the certificates and the parent SSL certificate: %s",buf); + } + return -1; +} + +#endif |