diff --git a/lib/common/tls.c b/lib/common/tls.c index b1804c5983..0ec440b55f 100644 --- a/lib/common/tls.c +++ b/lib/common/tls.c @@ -1,536 +1,538 @@ /* * Copyright 2024 the Pacemaker project contributors * * The version control history for this file may have further details. * * This source code is licensed under the GNU Lesser General Public License * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY. */ #include #include #include #include #include #include static char * get_gnutls_priorities(gnutls_credentials_type_t cred_type) { const char *prio_base = pcmk__env_option(PCMK__ENV_TLS_PRIORITIES); if (prio_base == NULL) { prio_base = PCMK__GNUTLS_PRIORITIES; } return crm_strdup_printf("%s:%s", prio_base, (cred_type == GNUTLS_CRD_ANON)? "+ANON-DH" : "+DHE-PSK:+PSK"); } static const char * tls_cred_str(gnutls_credentials_type_t cred_type) { if (cred_type == GNUTLS_CRD_ANON) { return "unauthenticated"; } else if (cred_type == GNUTLS_CRD_PSK) { return "shared-key-authenticated"; } else if (cred_type == GNUTLS_CRD_CERTIFICATE) { return "certificate-authenticated"; } else { return "unknown"; } } static int tls_load_x509_data(pcmk__tls_t *tls) { int rc; CRM_CHECK(tls->cred_type == GNUTLS_CRD_CERTIFICATE, return EINVAL); /* Load a trusted CA to be used to verify client certificates. Use * of this function instead of gnutls_certificate_set_x509_system_trust * means we do not look at the system-wide authorities installed in * /etc/pki somewhere. This requires the cluster admin to set up their * own CA. */ rc = gnutls_certificate_set_x509_trust_file(tls->credentials.cert, tls->ca_file, GNUTLS_X509_FMT_PEM); if (rc <= 0) { crm_err("Failed to set X509 CA file: %s", gnutls_strerror(rc)); return ENODATA; } /* If a Certificate Revocation List (CRL) file was given in the environment, * load that now so we know which clients have been banned. */ if (tls->crl_file != NULL) { rc = gnutls_certificate_set_x509_crl_file(tls->credentials.cert, tls->crl_file, GNUTLS_X509_FMT_PEM); if (rc < 0) { crm_err("Failed to set X509 CRL file: %s", gnutls_strerror(rc)); return ENODATA; } } /* NULL = no password for the key, GNUTLS_PKCS_PLAIN = unencrypted key * file */ rc = gnutls_certificate_set_x509_key_file2(tls->credentials.cert, tls->cert_file, tls->key_file, GNUTLS_X509_FMT_PEM, NULL, GNUTLS_PKCS_PLAIN); if (rc < 0) { crm_err("Failed to set X509 cert/key pair: %s", gnutls_strerror(rc)); return ENODATA; } return pcmk_rc_ok; } /*! * \internal * \brief Verify a peer's certificate * * \return 0 if the certificate is trusted and the gnutls handshake should * continue, -1 otherwise */ static int verify_peer_cert(gnutls_session_t session) { int rc; int type; unsigned int status; gnutls_datum_t out; /* NULL = no hostname comparison will be performed */ rc = gnutls_certificate_verify_peers3(session, NULL, &status); /* Success means it was able to perform the verification. We still have * to check status to see whether the cert is valid or not. */ if (rc != GNUTLS_E_SUCCESS) { crm_err("Failed to verify peer certificate: %s", gnutls_strerror(rc)); return -1; } if (status == 0) { /* The certificate is trusted. */ return 0; } type = gnutls_certificate_type_get(session); gnutls_certificate_verification_status_print(status, type, &out, 0); crm_err("Peer certificate invalid: %s", out.data); gnutls_free(out.data); return GNUTLS_E_CERTIFICATE_VERIFICATION_ERROR; } static void _gnutls_log_func(int level, const char *msg) { crm_trace("%s", msg); } void pcmk__free_tls(pcmk__tls_t *tls) { if (tls == NULL) { return; } /* This is only set on the server side. */ if (tls->server) { gnutls_dh_params_deinit(tls->dh_params); } if (tls->cred_type == GNUTLS_CRD_ANON) { if (tls->server) { gnutls_anon_free_server_credentials(tls->credentials.anon_s); } else { gnutls_anon_free_client_credentials(tls->credentials.anon_c); } } else if (tls->cred_type == GNUTLS_CRD_CERTIFICATE) { gnutls_certificate_free_credentials(tls->credentials.cert); } else if (tls->cred_type == GNUTLS_CRD_PSK) { if (tls->server) { gnutls_psk_free_server_credentials(tls->credentials.psk_s); } else { gnutls_psk_free_client_credentials(tls->credentials.psk_c); } } free(tls); tls = NULL; gnutls_global_deinit(); } int pcmk__init_tls(pcmk__tls_t **tls, bool server, gnutls_credentials_type_t cred_type) { int rc = pcmk_rc_ok; if (*tls != NULL) { return rc; } *tls = pcmk__assert_alloc(1, sizeof(pcmk__tls_t)); signal(SIGPIPE, SIG_IGN); /* gnutls_global_init is safe to call multiple times, but we have to call * gnutls_global_deinit the same number of times for that function to do * anything. * * FIXME: When we can use gnutls >= 3.3.0, we don't have to call * gnutls_global_init anymore. */ gnutls_global_init(); gnutls_global_set_log_level(8); gnutls_global_set_log_function(_gnutls_log_func); if (server) { rc = pcmk__init_tls_dh(&(*tls)->dh_params); if (rc != pcmk_rc_ok) { pcmk__free_tls(*tls); + *tls = NULL; return rc; } } (*tls)->cred_type = cred_type; (*tls)->server = server; if (cred_type == GNUTLS_CRD_ANON) { if (server) { gnutls_anon_allocate_server_credentials(&(*tls)->credentials.anon_s); gnutls_anon_set_server_dh_params((*tls)->credentials.anon_s, (*tls)->dh_params); } else { gnutls_anon_allocate_client_credentials(&(*tls)->credentials.anon_c); } } else if (cred_type == GNUTLS_CRD_CERTIFICATE) { /* Try the PCMK_ version of each environment variable first, and if * it's not set then try the CIB_ version. */ (*tls)->ca_file = pcmk__env_option(PCMK__ENV_CA_FILE); if (pcmk__str_empty((*tls)->ca_file)) { (*tls)->ca_file = getenv("CIB_ca_file"); } (*tls)->cert_file = pcmk__env_option(PCMK__ENV_CERT_FILE); if (pcmk__str_empty((*tls)->cert_file)) { (*tls)->cert_file = getenv("CIB_cert_file"); } (*tls)->crl_file = pcmk__env_option(PCMK__ENV_CRL_FILE); if (pcmk__str_empty((*tls)->crl_file)) { (*tls)->crl_file = getenv("CIB_crl_file"); } (*tls)->key_file = pcmk__env_option(PCMK__ENV_KEY_FILE); if (pcmk__str_empty((*tls)->key_file)) { (*tls)->key_file = getenv("CIB_key_file"); } gnutls_certificate_allocate_credentials(&(*tls)->credentials.cert); if (server) { gnutls_certificate_set_dh_params((*tls)->credentials.cert, (*tls)->dh_params); } rc = tls_load_x509_data(*tls); if (rc != pcmk_rc_ok) { pcmk__free_tls(*tls); + *tls = NULL; return rc; } } else if (cred_type == GNUTLS_CRD_PSK) { if (server) { gnutls_psk_allocate_server_credentials(&(*tls)->credentials.psk_s); gnutls_psk_set_server_dh_params((*tls)->credentials.psk_s, (*tls)->dh_params); } else { gnutls_psk_allocate_client_credentials(&(*tls)->credentials.psk_c); } } return rc; } int pcmk__init_tls_dh(gnutls_dh_params_t *dh_params) { int rc = GNUTLS_E_SUCCESS; unsigned int dh_bits = 0; int dh_max_bits = 0; rc = gnutls_dh_params_init(dh_params); if (rc != GNUTLS_E_SUCCESS) { goto error; } dh_bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_NORMAL); if (dh_bits == 0) { rc = GNUTLS_E_DH_PRIME_UNACCEPTABLE; goto error; } pcmk__scan_min_int(pcmk__env_option(PCMK__ENV_DH_MAX_BITS), &dh_max_bits, 0); if ((dh_max_bits > 0) && (dh_bits > dh_max_bits)) { dh_bits = dh_max_bits; } crm_info("Generating Diffie-Hellman parameters with %u-bit prime for TLS", dh_bits); rc = gnutls_dh_params_generate2(*dh_params, dh_bits); if (rc != GNUTLS_E_SUCCESS) { goto error; } return pcmk_rc_ok; error: crm_err("Could not initialize Diffie-Hellman parameters for TLS: %s " QB_XS " rc=%d", gnutls_strerror(rc), rc); return EPROTO; } gnutls_session_t pcmk__new_tls_session(pcmk__tls_t *tls, int csock) { unsigned int conn_type = tls->server ? GNUTLS_SERVER : GNUTLS_CLIENT; int rc = GNUTLS_E_SUCCESS; char *prio = NULL; gnutls_session_t session = NULL; rc = gnutls_init(&session, conn_type); if (rc != GNUTLS_E_SUCCESS) { goto error; } /* Determine list of acceptable ciphers, etc. Pacemaker always adds the * values required for its functionality. * * For an example of anonymous authentication, see: * http://www.manpagez.com/info/gnutls/gnutls-2.10.4/gnutls_81.php#Echo-Server-with-anonymous-authentication */ prio = get_gnutls_priorities(tls->cred_type); /* @TODO On the server side, it would be more efficient to cache the * priority with gnutls_priority_init2() and set it with * gnutls_priority_set() for all sessions. */ rc = gnutls_priority_set_direct(session, prio, NULL); if (rc != GNUTLS_E_SUCCESS) { goto error; } gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) GINT_TO_POINTER(csock)); /* gnutls does not make this easy */ if (tls->cred_type == GNUTLS_CRD_ANON && tls->server) { rc = gnutls_credentials_set(session, tls->cred_type, tls->credentials.anon_s); } else if (tls->cred_type == GNUTLS_CRD_ANON) { rc = gnutls_credentials_set(session, tls->cred_type, tls->credentials.anon_c); } else if (tls->cred_type == GNUTLS_CRD_CERTIFICATE) { rc = gnutls_credentials_set(session, tls->cred_type, tls->credentials.cert); } else if (tls->cred_type == GNUTLS_CRD_PSK && tls->server) { rc = gnutls_credentials_set(session, tls->cred_type, tls->credentials.psk_s); } else if (tls->cred_type == GNUTLS_CRD_PSK) { rc = gnutls_credentials_set(session, tls->cred_type, tls->credentials.psk_c); } else { crm_err("Unknown credential type: %d", tls->cred_type); rc = EINVAL; goto error; } if (rc != GNUTLS_E_SUCCESS) { goto error; } free(prio); if (tls->cred_type == GNUTLS_CRD_CERTIFICATE) { if (conn_type == GNUTLS_SERVER) { /* Require the client to send a certificate for the server to verify. */ gnutls_certificate_server_set_request(session, GNUTLS_CERT_REQUIRE); } /* Register a function to verify the peer's certificate. * * FIXME: When we can require gnutls >= 3.4.6, remove verify_peer_cert * and use gnutls_session_set_verify_cert instead. */ gnutls_certificate_set_verify_function(tls->credentials.cert, verify_peer_cert); } return session; error: crm_err("Could not initialize %s TLS %s session: %s " QB_XS " rc=%d priority='%s'", tls_cred_str(tls->cred_type), (conn_type == GNUTLS_SERVER)? "server" : "client", gnutls_strerror(rc), rc, prio); free(prio); if (session != NULL) { gnutls_deinit(session); } return NULL; } int pcmk__read_handshake_data(const pcmk__client_t *client) { int rc = 0; pcmk__assert((client != NULL) && (client->remote != NULL) && (client->remote->tls_session != NULL)); do { rc = gnutls_handshake(client->remote->tls_session); } while (rc == GNUTLS_E_INTERRUPTED); if (rc == GNUTLS_E_AGAIN) { /* No more data is available at the moment. This function should be * invoked again once the client sends more. */ return EAGAIN; } else if (rc != GNUTLS_E_SUCCESS) { crm_err("TLS handshake with remote client failed: %s " QB_XS " rc=%d", gnutls_strerror(rc), rc); return EPROTO; } return pcmk_rc_ok; } void pcmk__tls_add_psk_key(pcmk__tls_t *tls, gnutls_datum_t *key) { gnutls_psk_set_client_credentials(tls->credentials.psk_c, DEFAULT_REMOTE_USERNAME, key, GNUTLS_PSK_KEY_RAW); } void pcmk__tls_add_psk_callback(pcmk__tls_t *tls, gnutls_psk_server_credentials_function *cb) { gnutls_psk_set_server_credentials_function(tls->credentials.psk_s, cb); } void pcmk__tls_check_cert_expiration(gnutls_session_t session) { gnutls_x509_crt_t cert; const gnutls_datum_t *datum = NULL; time_t expiry; if (session == NULL) { return; } if (gnutls_certificate_type_get(session) != GNUTLS_CRT_X509) { return; } datum = gnutls_certificate_get_ours(session); if (datum == NULL) { return; } gnutls_x509_crt_init(&cert); gnutls_x509_crt_import(cert, datum, GNUTLS_X509_FMT_DER); expiry = gnutls_x509_crt_get_expiration_time(cert); if (expiry != -1) { time_t now = time(NULL); /* If the cert is going to expire within ~ one month (30 days), log it */ if (expiry - now <= 60 * 60 * 24 * 30) { crm_time_t *expiry_t = pcmk__copy_timet(expiry); crm_time_log(LOG_WARNING, "TLS certificate will expire on", expiry_t, crm_time_log_date | crm_time_log_timeofday); crm_time_free(expiry_t); } } gnutls_x509_crt_deinit(cert); } int pcmk__tls_client_try_handshake(pcmk__remote_t *remote, int *gnutls_rc) { int rc = pcmk_rc_ok; if (gnutls_rc != NULL) { *gnutls_rc = GNUTLS_E_SUCCESS; } rc = gnutls_handshake(remote->tls_session); switch (rc) { case GNUTLS_E_SUCCESS: rc = pcmk_rc_ok; break; case GNUTLS_E_INTERRUPTED: case GNUTLS_E_AGAIN: rc = EAGAIN; break; default: if (gnutls_rc != NULL) { *gnutls_rc = rc; } rc = EPROTO; break; } return rc; } int pcmk__tls_client_handshake(pcmk__remote_t *remote, int timeout_sec, int *gnutls_rc) { const time_t time_limit = time(NULL) + timeout_sec; do { int rc = pcmk__tls_client_try_handshake(remote, gnutls_rc); if (rc != EAGAIN) { return rc; } } while (time(NULL) < time_limit); return ETIME; } bool pcmk__x509_enabled(void) { /* Environment variables for servers come through the sysconfig file, and * have names like PCMK_. Environment variables for clients come * from the environment and have names like CIB_. This function * is used for both, so we need to check both. */ return (!pcmk__str_empty(pcmk__env_option(PCMK__ENV_CERT_FILE)) || !pcmk__str_empty(getenv("CIB_cert_file"))) && (!pcmk__str_empty(pcmk__env_option(PCMK__ENV_CA_FILE)) || !pcmk__str_empty(getenv("CIB_ca_file"))) && (!pcmk__str_empty(pcmk__env_option(PCMK__ENV_KEY_FILE)) || !pcmk__str_empty(getenv("CIB_key_file"))); }