[libvirt] [PATCH 04/10] Generic module for handling TLS encryption and x509 certs

This provides two modules for handling TLS * virNetTLSContext provides the process-wide state, in particular all the x509 credentials, DH params and x509 whitelists * virNetTLSSession provides the per-connection state, ie the TLS session itself. The virNetTLSContext provides APIs for validating a TLS session's x509 credentials. The virNetTLSSession includes APIs for performing the initial TLS handshake and sending/recving encrypted data * src/Makefile.am: Add to libvirt-net-rpc.la * src/rpc/virnettlscontext.c, src/rpc/virnettlscontext.h: Generic TLS handling code --- cfg.mk | 1 + po/POTFILES.in | 1 + src/Makefile.am | 5 +- src/rpc/virnettlscontext.c | 894 ++++++++++++++++++++++++++++++++++++++++++++ src/rpc/virnettlscontext.h | 99 +++++ 5 files changed, 999 insertions(+), 1 deletions(-) create mode 100644 src/rpc/virnettlscontext.c create mode 100644 src/rpc/virnettlscontext.h diff --git a/cfg.mk b/cfg.mk index b6f3dd9..c0062af 100644 --- a/cfg.mk +++ b/cfg.mk @@ -127,6 +127,7 @@ useless_free_options = \ --name=virLastErrFreeData \ --name=virNetMessageFree \ --name=virNetSocketFree \ + --name=virNetTLSSessionFree \ --name=virNWFilterDefFree \ --name=virNWFilterEntryFree \ --name=virNWFilterHashTableFree \ diff --git a/po/POTFILES.in b/po/POTFILES.in index b5d77f3..0aa52b2 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -71,6 +71,7 @@ src/remote/remote_client_bodies.h src/remote/remote_driver.c src/rpc/virnetmessage.c src/rpc/virnetsocket.c +src/rpc/virnettlscontext.c src/secret/secret_driver.c src/security/security_apparmor.c src/security/security_dac.c diff --git a/src/Makefile.am b/src/Makefile.am index 2a2c177..a5f8ddc 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -1192,10 +1192,13 @@ noinst_LTLIBRARIES += libvirt-net-rpc.la libvirt_net_rpc_la_SOURCES = \ rpc/virnetmessage.h rpc/virnetmessage.c \ rpc/virnetprotocol.h rpc/virnetprotocol.c \ - rpc/virnetsocket.h rpc/virnetsocket.c + rpc/virnetsocket.h rpc/virnetsocket.c \ + rpc/virnettlscontext.h rpc/virnettlscontext.c libvirt_net_rpc_la_CFLAGS = \ + $(GNUTLS_CFLAGS) \ $(AM_CFLAGS) libvirt_net_rpc_la_LDFLAGS = \ + $(GNUTLS_LIBS) \ $(AM_LDFLAGS) \ $(CYGWIN_EXTRA_LDFLAGS) \ $(MINGW_EXTRA_LDFLAGS) diff --git a/src/rpc/virnettlscontext.c b/src/rpc/virnettlscontext.c new file mode 100644 index 0000000..a6acdb3 --- /dev/null +++ b/src/rpc/virnettlscontext.c @@ -0,0 +1,894 @@ +/* + * virnettlscontext.c: TLS encryption/x509 handling + * + * Copyright (C) 2010-2011 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <config.h> + +#include <unistd.h> +#include <fnmatch.h> +#include <stdlib.h> + +#include <gnutls/gnutls.h> +#include <gnutls/x509.h> +#include "gnutls_1_0_compat.h" + +#include "virnettlscontext.h" + +#include "memory.h" +#include "virterror_internal.h" +#include "util.h" +#include "logging.h" +#include "configmake.h" + +#define DH_BITS 1024 + +#define LIBVIRT_PKI_DIR SYSCONFDIR "/pki" +#define LIBVIRT_CACERT LIBVIRT_PKI_DIR "/CA/cacert.pem" +#define LIBVIRT_CACRL LIBVIRT_PKI_DIR "/CA/cacrl.pem" +#define LIBVIRT_CLIENTKEY LIBVIRT_PKI_DIR "/libvirt/private/clientkey.pem" +#define LIBVIRT_CLIENTCERT LIBVIRT_PKI_DIR "/libvirt/clientcert.pem" +#define LIBVIRT_SERVERKEY LIBVIRT_PKI_DIR "/libvirt/private/serverkey.pem" +#define LIBVIRT_SERVERCERT LIBVIRT_PKI_DIR "/libvirt/servercert.pem" + +#define VIR_FROM_THIS VIR_FROM_RPC +#define virNetError(code, ...) \ + virReportErrorHelper(VIR_FROM_THIS, code, __FILE__, \ + __FUNCTION__, __LINE__, __VA_ARGS__) + +struct _virNetTLSContext { + int refs; + + gnutls_certificate_credentials_t x509cred; + gnutls_dh_params_t dhParams; + + bool isServer; + bool requireValidCert; + const char *const*x509dnWhitelist; +}; + +struct _virNetTLSSession { + int refs; + + bool handshakeComplete; + + char *hostname; + gnutls_session_t session; + virNetTLSSessionWriteFunc writeFunc; + virNetTLSSessionReadFunc readFunc; + void *opaque; +}; + + +static int +virNetTLSContextCheckCertFile(const char *type, const char *file, bool allowMissing) +{ + if (!virFileExists(file)) { + if (allowMissing) + return 1; + + virReportSystemError(errno, + _("Cannot read %s '%s'"), + type, file); + return -1; + } + return 0; +} + + +static void virNetTLSLog(int level, const char *str) { + VIR_DEBUG("%d %s", level, str); +} + +static int virNetTLSContextLoadCredentials(virNetTLSContextPtr ctxt, + bool isServer, + const char *cacert, + const char *cacrl, + const char *cert, + const char *key) +{ + int ret = -1; + int err; + + if (cacert && cacert[0] != '\0') { + if (virNetTLSContextCheckCertFile("CA certificate", cacert, false) < 0) + goto cleanup; + + VIR_DEBUG("loading CA cert from %s", cacert); + err = gnutls_certificate_set_x509_trust_file(ctxt->x509cred, + cacert, + GNUTLS_X509_FMT_PEM); + if (err < 0) { + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Unable to set x509 CA certificate: %s: %s"), + cacert, gnutls_strerror (err)); + goto cleanup; + } + } + + if (cacrl && cacrl[0] != '\0') { + int rv; + if ((rv = virNetTLSContextCheckCertFile("CA revocation list", cacrl, true)) < 0) + goto cleanup; + + if (rv == 0) { + VIR_DEBUG("loading CRL from %s", cacrl); + err = gnutls_certificate_set_x509_crl_file(ctxt->x509cred, + cacrl, + GNUTLS_X509_FMT_PEM); + if (err < 0) { + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Unable to set x509 certificate revocation list: %s: %s"), + cacrl, gnutls_strerror(err)); + goto cleanup; + } + } else { + VIR_DEBUG("Skipping non-existent CA CRL %s", cacrl); + } + } + + if (cert && cert[0] != '\0' && key && key[0] != '\0') { + int rv; + if ((rv = virNetTLSContextCheckCertFile("certificate", cert, !isServer)) < 0) + goto cleanup; + if (rv == 0 && + (rv = virNetTLSContextCheckCertFile("private key", key, !isServer)) < 0) + goto cleanup; + + if (rv == 0) { + VIR_DEBUG("loading cert and key from %s and %s", cert, key); + err = + gnutls_certificate_set_x509_key_file(ctxt->x509cred, + cert, key, + GNUTLS_X509_FMT_PEM); + if (err < 0) { + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Unable to set x509 key and certificate: %s, %s: %s"), + key, cert, gnutls_strerror(err)); + goto cleanup; + } + } else { + VIR_DEBUG("Skipping non-existant cert %s key %s on client", cert, key); + } + } + + ret = 0; + +cleanup: + return ret; +} + + +static virNetTLSContextPtr virNetTLSContextNew(const char *cacert, + const char *cacrl, + const char *cert, + const char *key, + const char *const*x509dnWhitelist, + bool requireValidCert, + bool isServer) +{ + virNetTLSContextPtr ctxt; + char *gnutlsdebug; + int err; + + VIR_DEBUG("cacert=%s cacrl=%s cert=%s key=%s requireValid=%d isServer=%d", + cacert, NULLSTR(cacrl), cert, key, requireValidCert, isServer); + + if (VIR_ALLOC(ctxt) < 0) { + virReportOOMError(); + return NULL; + } + + ctxt->refs = 1; + + /* Initialise GnuTLS. */ + gnutls_global_init(); + + if ((gnutlsdebug = getenv("LIBVIRT_GNUTLS_DEBUG")) != NULL) { + int val; + if (virStrToLong_i(gnutlsdebug, NULL, 10, &val) < 0) + val = 10; + gnutls_global_set_log_level(val); + gnutls_global_set_log_function(virNetTLSLog); + VIR_DEBUG("Enabled GNUTLS debug"); + } + + + err = gnutls_certificate_allocate_credentials(&ctxt->x509cred); + if (err) { + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Unable to allocate x509 credentials: %s"), + gnutls_strerror(err)); + goto error; + } + + if (virNetTLSContextLoadCredentials(ctxt, isServer, cacert, cacrl, cert, key) < 0) + goto error; + + /* Generate Diffie Hellman parameters - for use with DHE + * kx algorithms. These should be discarded and regenerated + * once a day, once a week or once a month. Depending on the + * security requirements. + */ + if (isServer) { + err = gnutls_dh_params_init(&ctxt->dhParams); + if (err < 0) { + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Unable to initialize diffie-hellman parameters: %s"), + gnutls_strerror(err)); + goto error; + } + err = gnutls_dh_params_generate2(ctxt->dhParams, DH_BITS); + if (err < 0) { + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Unable to generate diffie-hellman parameters: %s"), + gnutls_strerror(err)); + goto error; + } + + gnutls_certificate_set_dh_params(ctxt->x509cred, + ctxt->dhParams); + } + + ctxt->requireValidCert = requireValidCert; + ctxt->x509dnWhitelist = x509dnWhitelist; + ctxt->isServer = isServer; + + return ctxt; + +error: + if (isServer) + gnutls_dh_params_deinit(ctxt->dhParams); + gnutls_certificate_free_credentials(ctxt->x509cred); + VIR_FREE(ctxt); + return NULL; +} + + +static int virNetTLSContextLocateCredentials(const char *pkipath, + bool tryUserPkiPath, + bool isServer, + char **cacert, + char **cacrl, + char **cert, + char **key) +{ + char *userdir = NULL; + char *user_pki_path = NULL; + + *cacert = NULL; + *cacrl = NULL; + *key = NULL; + *cert = NULL; + + VIR_DEBUG("pkipath=%s isServer=%d tryUserPkiPath=%d", + pkipath, isServer, tryUserPkiPath); + + /* Explicit path, then use that no matter whether the + * files actually exist there + */ + if (pkipath) { + VIR_DEBUG("Told to use TLS credentials in %s", pkipath); + if ((virAsprintf(cacert, "%s/%s", pkipath, + "cacert.pem")) < 0) + goto out_of_memory; + if ((virAsprintf(cacrl, "%s/%s", pkipath, + "cacrl.pem")) < 0) + goto out_of_memory; + if ((virAsprintf(key, "%s/%s", pkipath, + isServer ? "serverkey.pem" : "clientkey.pem")) < 0) + goto out_of_memory; + + if ((virAsprintf(cert, "%s/%s", pkipath, + isServer ? "servercert.pem" : "clientcert.pem")) < 0) + goto out_of_memory; + } else if (tryUserPkiPath) { + /* Check to see if $HOME/.pki contains at least one of the + * files and if so, use that + */ + userdir = virGetUserDirectory(getuid()); + + if (!userdir) + goto out_of_memory; + + if (virAsprintf(&user_pki_path, "%s/.pki/libvirt", userdir) < 0) + goto out_of_memory; + + VIR_DEBUG("Trying to find TLS user credentials in %s", user_pki_path); + + if ((virAsprintf(cacert, "%s/%s", user_pki_path, + "cacert.pem")) < 0) + goto out_of_memory; + + if ((virAsprintf(cacrl, "%s/%s", user_pki_path, + "cacrl.pem")) < 0) + goto out_of_memory; + + if ((virAsprintf(key, "%s/%s", user_pki_path, + isServer ? "serverkey.pem" : "clientkey.pem")) < 0) + goto out_of_memory; + + if ((virAsprintf(cert, "%s/%s", user_pki_path, + isServer ? "servercert.pem" : "clientcert.pem")) < 0) + goto out_of_memory; + + /* + * If some of the files can't be found, fallback + * to the global location for them + */ + if (!virFileExists(*cacert)) + VIR_FREE(*cacert); + if (!virFileExists(*cacrl)) + VIR_FREE(*cacrl); + + /* Check these as a pair, since it they are + * mutually dependent + */ + if (!virFileExists(*key) || !virFileExists(*cert)) { + VIR_FREE(*key); + VIR_FREE(*cert); + } + } + + /* No explicit path, or user path didn't exist, so + * fallback to global defaults + */ + if (!*cacert) { + VIR_DEBUG("Using default TLS CA certificate path"); + if (!(*cacert = strdup(LIBVIRT_CACERT))) + goto out_of_memory; + } + + if (!*cacrl) { + VIR_DEBUG("Using default TLS CA revocation list path"); + if (!(*cacrl = strdup(LIBVIRT_CACRL))) + goto out_of_memory; + } + + if (!*key && !*cert) { + VIR_DEBUG("Using default TLS key/certificate path"); + if (!(*key = strdup(isServer ? LIBVIRT_SERVERKEY : LIBVIRT_CLIENTKEY))) + goto out_of_memory; + + if (!(*cert = strdup(isServer ? LIBVIRT_SERVERCERT : LIBVIRT_CLIENTCERT))) + goto out_of_memory; + } + + VIR_FREE(user_pki_path); + VIR_FREE(userdir); + + return 0; + +out_of_memory: + virReportOOMError(); + VIR_FREE(*cacert); + VIR_FREE(*cacrl); + VIR_FREE(*key); + VIR_FREE(*cert); + VIR_FREE(user_pki_path); + VIR_FREE(userdir); + return -1; +} + + +static virNetTLSContextPtr virNetTLSContextNewPath(const char *pkipath, + bool tryUserPkiPath, + const char *const*x509dnWhitelist, + bool requireValidCert, + bool isServer) +{ + char *cacert = NULL, *cacrl = NULL, *key = NULL, *cert = NULL; + virNetTLSContextPtr ctxt = NULL; + + if (virNetTLSContextLocateCredentials(pkipath, tryUserPkiPath, isServer, + &cacert, &cacrl, &key, &cert) < 0) + return NULL; + + ctxt = virNetTLSContextNew(cacert, cacrl, key, cert, + x509dnWhitelist, requireValidCert, isServer); + + VIR_FREE(cacert); + VIR_FREE(cacrl); + VIR_FREE(key); + VIR_FREE(cert); + + return ctxt; +} + +virNetTLSContextPtr virNetTLSContextNewServerPath(const char *pkipath, + bool tryUserPkiPath, + const char *const*x509dnWhitelist, + bool requireValidCert) +{ + return virNetTLSContextNewPath(pkipath, tryUserPkiPath, + x509dnWhitelist, requireValidCert, true); +} + +virNetTLSContextPtr virNetTLSContextNewClientPath(const char *pkipath, + bool tryUserPkiPath, + bool requireValidCert) +{ + return virNetTLSContextNewPath(pkipath, tryUserPkiPath, + NULL, requireValidCert, false); +} + + +virNetTLSContextPtr virNetTLSContextNewServer(const char *cacert, + const char *cacrl, + const char *cert, + const char *key, + const char *const*x509dnWhitelist, + bool requireValidCert) +{ + return virNetTLSContextNew(cacert, cacrl, key, cert, + x509dnWhitelist, requireValidCert, true); +} + + +virNetTLSContextPtr virNetTLSContextNewClient(const char *cacert, + const char *cacrl, + const char *cert, + const char *key, + bool requireValidCert) +{ + return virNetTLSContextNew(cacert, cacrl, key, cert, + NULL, requireValidCert, false); +} + + +void virNetTLSContextRef(virNetTLSContextPtr ctxt) +{ + ctxt->refs++; +} + + +/* Check DN is on tls_allowed_dn_list. */ +static int +virNetTLSContextCheckDN(virNetTLSContextPtr ctxt, + const char *dname) +{ + const char *const*wildcards; + + /* If the list is not set, allow any DN. */ + wildcards = ctxt->x509dnWhitelist; + if (!wildcards) + return 1; + + while (*wildcards) { + int ret = fnmatch (*wildcards, dname, 0); + if (ret == 0) /* Succesful match */ + return 1; + if (ret != FNM_NOMATCH) { + virNetError(VIR_ERR_INTERNAL_ERROR, + _("Malformed TLS whitelist regular expression '%s'"), + *wildcards); + return -1; + } + + wildcards++; + } + + /* Log the client's DN for debugging */ + VIR_DEBUG("Failed whitelist check for client DN '%s'", dname); + + /* This is the most common error: make it informative. */ + virNetError(VIR_ERR_SYSTEM_ERROR, "%s", + _("Client's Distinguished Name is not on the list " + "of allowed clients (tls_allowed_dn_list). Use " + "'certtool -i --infile clientcert.pem' to view the" + "Distinguished Name field in the client certificate," + "or run this daemon with --verbose option.")); + return 0; +} + +static int virNetTLSContextValidCertificate(virNetTLSContextPtr ctxt, + virNetTLSSessionPtr sess) +{ + int ret; + unsigned int status; + const gnutls_datum_t *certs; + unsigned int nCerts, i; + time_t now; + char name[256]; + size_t namesize = sizeof name; + + memset(name, 0, namesize); + + if ((ret = gnutls_certificate_verify_peers2(sess->session, &status)) < 0){ + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Unable to verify TLS peer: %s"), + gnutls_strerror(ret)); + goto authdeny; + } + + if ((now = time(NULL)) == ((time_t)-1)) { + virReportSystemError(errno, "%s", + _("cannot get current time")); + goto authfail; + } + + if (status != 0) { + const char *reason = _("Invalid certificate"); + + if (status & GNUTLS_CERT_INVALID) + reason = _("The certificate is not trusted."); + + if (status & GNUTLS_CERT_SIGNER_NOT_FOUND) + reason = _("The certificate hasn't got a known issuer."); + + if (status & GNUTLS_CERT_REVOKED) + reason = _("The certificate has been revoked."); + +#ifndef GNUTLS_1_0_COMPAT + if (status & GNUTLS_CERT_INSECURE_ALGORITHM) + reason = _("The certificate uses an insecure algorithm"); +#endif + + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Certificate failed validation: %s"), + reason); + goto authdeny; + } + + if (gnutls_certificate_type_get(sess->session) != GNUTLS_CRT_X509) { + virNetError(VIR_ERR_SYSTEM_ERROR, "%s", + _("Only x509 certificates are supported")); + goto authdeny; + } + + if (!(certs = gnutls_certificate_get_peers(sess->session, &nCerts))) { + virNetError(VIR_ERR_SYSTEM_ERROR, "%s", + _("The certificate has no peers")); + goto authdeny; + } + + for (i = 0; i < nCerts; i++) { + gnutls_x509_crt_t cert; + + if (gnutls_x509_crt_init(&cert) < 0) { + virNetError(VIR_ERR_SYSTEM_ERROR, "%s", + _("Unable to initialize certificate")); + goto authfail; + } + + if (gnutls_x509_crt_import(cert, &certs[i], GNUTLS_X509_FMT_DER) < 0) { + virNetError(VIR_ERR_SYSTEM_ERROR, "%s", + _("Unable to load certificate")); + gnutls_x509_crt_deinit(cert); + goto authfail; + } + + if (gnutls_x509_crt_get_expiration_time(cert) < now) { + virNetError(VIR_ERR_SYSTEM_ERROR, "%s", + _("The client certificate has expired")); + gnutls_x509_crt_deinit(cert); + goto authdeny; + } + + if (gnutls_x509_crt_get_activation_time(cert) > now) { + virNetError(VIR_ERR_SYSTEM_ERROR, "%s", + _("The client certificate is not yet active")); + gnutls_x509_crt_deinit(cert); + goto authdeny; + } + + if (i == 0) { + ret = gnutls_x509_crt_get_dn(cert, name, &namesize); + if (ret != 0) { + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Failed to get certificate distinguished name: %s"), + gnutls_strerror(ret)); + gnutls_x509_crt_deinit(cert); + goto authfail; + } + + if (virNetTLSContextCheckDN(ctxt, name) <= 0) { + gnutls_x509_crt_deinit(cert); + goto authdeny; + } + + if (sess->hostname && + !gnutls_x509_crt_check_hostname(cert, sess->hostname)) { + virNetError(VIR_ERR_RPC, + _("Certificate's owner does not match the hostname (%s)"), + sess->hostname); + gnutls_x509_crt_deinit(cert); + goto authdeny; + } + } + } + +#if 0 + PROBE(CLIENT_TLS_ALLOW, "fd=%d, name=%s", + virNetServerClientGetFD(client), name); +#endif + return 0; + +authdeny: +#if 0 + PROBE(CLIENT_TLS_DENY, "fd=%d, name=%s", + virNetServerClientGetFD(client), name); +#endif + return -1; + +authfail: +#if 0 + PROBE(CLIENT_TLS_FAIL, "fd=%d", + virNetServerClientGetFD(client)); +#endif + return -1; +} + +int virNetTLSContextCheckCertificate(virNetTLSContextPtr ctxt, + virNetTLSSessionPtr sess) { + if (virNetTLSContextValidCertificate(ctxt, sess) < 0) { + if (ctxt->requireValidCert) { + virNetError(VIR_ERR_AUTH_FAILED, "%s", + _("Failed to verify peer's certificate")); + return -1; + } + VIR_INFO("Ignoring bad certificate at user request"); + } + return 0; +} + +void virNetTLSContextFree(virNetTLSContextPtr ctxt) +{ + if (!ctxt) + return; + + ctxt->refs--; + if (ctxt->refs > 0) + return; + + gnutls_dh_params_deinit(ctxt->dhParams); + gnutls_certificate_free_credentials(ctxt->x509cred); + VIR_FREE(ctxt); +} + + + +static ssize_t +virNetTLSSessionPush(void *opaque, const void *buf, size_t len) +{ + virNetTLSSessionPtr sess = opaque; + if (!sess->writeFunc) { + VIR_WARN("TLS session push with missing read function"); + errno = EIO; + return -1; + }; + + return sess->writeFunc(buf, len, sess->opaque); +} + + +static ssize_t +virNetTLSSessionPull(void *opaque, void *buf, size_t len) +{ + virNetTLSSessionPtr sess = opaque; + if (!sess->readFunc) { + VIR_WARN("TLS session pull with missing read function"); + errno = EIO; + return -1; + }; + + return sess->readFunc(buf, len, sess->opaque); +} + + +virNetTLSSessionPtr virNetTLSSessionNew(virNetTLSContextPtr ctxt, + const char *hostname) +{ + virNetTLSSessionPtr sess; + int err; + static const int cert_type_priority[] = { GNUTLS_CRT_X509, 0 }; + + VIR_DEBUG("ctxt=%p hostname=%s isServer=%d", ctxt, NULLSTR(hostname), ctxt->isServer); + + if (VIR_ALLOC(sess) < 0) { + virReportOOMError(); + return NULL; + } + + sess->refs = 1; + if (hostname && + !(sess->hostname = strdup(hostname))) { + virReportOOMError(); + goto error; + } + + if ((err = gnutls_init(&sess->session, + ctxt->isServer ? GNUTLS_SERVER : GNUTLS_CLIENT)) != 0) { + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Failed to initialize TLS session: %s"), + gnutls_strerror(err)); + goto error; + } + + /* avoid calling all the priority functions, since the defaults + * are adequate. + */ + if ((err = gnutls_set_default_priority(sess->session)) != 0 || + (err = gnutls_certificate_type_set_priority(sess->session, + cert_type_priority))) { + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Failed to set TLS session priority %s"), + gnutls_strerror(err)); + goto error; + } + + if ((err = gnutls_credentials_set(sess->session, + GNUTLS_CRD_CERTIFICATE, + ctxt->x509cred)) != 0) { + virNetError(VIR_ERR_SYSTEM_ERROR, + _("Failed set TLS x509 credentials: %s"), + gnutls_strerror(err)); + goto error; + } + + /* request client certificate if any. + */ + if (ctxt->isServer) { + gnutls_certificate_server_set_request(sess->session, GNUTLS_CERT_REQUEST); + + gnutls_dh_set_prime_bits(sess->session, DH_BITS); + } + + gnutls_transport_set_ptr(sess->session, sess); + gnutls_transport_set_push_function(sess->session, + virNetTLSSessionPush); + gnutls_transport_set_pull_function(sess->session, + virNetTLSSessionPull); + + return sess; + +error: + virNetTLSSessionFree(sess); + return NULL; +} + + +void virNetTLSSessionRef(virNetTLSSessionPtr sess) +{ + sess->refs++; +} + +void virNetTLSSessionSetIOCallbacks(virNetTLSSessionPtr sess, + virNetTLSSessionWriteFunc writeFunc, + virNetTLSSessionReadFunc readFunc, + void *opaque) +{ + sess->writeFunc = writeFunc; + sess->readFunc = readFunc; + sess->opaque = opaque; +} + + +ssize_t virNetTLSSessionWrite(virNetTLSSessionPtr sess, + const char *buf, size_t len) +{ + ssize_t ret; + ret = gnutls_record_send(sess->session, buf, len); + + if (ret >= 0) + return ret; + + switch (ret) { + case GNUTLS_E_AGAIN: + errno = EAGAIN; + break; + case GNUTLS_E_INTERRUPTED: + errno = EINTR; + break; + default: + errno = EIO; + break; + } + + return -1; +} + +ssize_t virNetTLSSessionRead(virNetTLSSessionPtr sess, + char *buf, size_t len) +{ + ssize_t ret; + + ret = gnutls_record_recv(sess->session, buf, len); + + if (ret >= 0) + return ret; + + switch (ret) { + case GNUTLS_E_AGAIN: + errno = EAGAIN; + break; + case GNUTLS_E_INTERRUPTED: + errno = EINTR; + break; + default: + errno = EIO; + break; + } + + return -1; +} + +int virNetTLSSessionHandshake(virNetTLSSessionPtr sess) +{ + VIR_DEBUG("sess=%p", sess); + int ret = gnutls_handshake(sess->session); + VIR_DEBUG("Ret=%d", ret); + if (ret == 0) { + sess->handshakeComplete = true; + VIR_DEBUG("Handshake is complete"); + return 0; + } + if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) + return 1; + +#if 0 + PROBE(CLIENT_TLS_FAIL, "fd=%d", + virNetServerClientGetFD(client)); +#endif + + virNetError(VIR_ERR_AUTH_FAILED, + _("TLS handshake failed %s"), + gnutls_strerror(ret)); + return -1; +} + +virNetTLSSessionHandshakeStatus +virNetTLSSessionGetHandshakeStatus(virNetTLSSessionPtr sess) +{ + if (sess->handshakeComplete) + return VIR_NET_TLS_HANDSHAKE_COMPLETE; + else if (gnutls_record_get_direction(sess->session) == 0) + return VIR_NET_TLS_HANDSHAKE_RECVING; + else + return VIR_NET_TLS_HANDSHAKE_SENDING; +} + +int virNetTLSSessionGetKeySize(virNetTLSSessionPtr sess) +{ + gnutls_cipher_algorithm_t cipher; + int ssf; + + cipher = gnutls_cipher_get(sess->session); + if (!(ssf = gnutls_cipher_get_key_size(cipher))) { + virNetError(VIR_ERR_INTERNAL_ERROR, "%s", + _("invalid cipher size for TLS session")); + return -1; + } + + return ssf; +} + + +void virNetTLSSessionFree(virNetTLSSessionPtr sess) +{ + if (!sess) + return; + + sess->refs--; + if (sess->refs > 0) + return; + + VIR_FREE(sess->hostname); + gnutls_deinit(sess->session); + VIR_FREE(sess); +} diff --git a/src/rpc/virnettlscontext.h b/src/rpc/virnettlscontext.h new file mode 100644 index 0000000..f23667f --- /dev/null +++ b/src/rpc/virnettlscontext.h @@ -0,0 +1,99 @@ +/* + * virnettlscontext.h: TLS encryption/x509 handling + * + * Copyright (C) 2010-2011 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef __VIR_NET_TLS_CONTEXT_H__ +# define __VIR_NET_TLS_CONTEXT_H__ + +# include "internal.h" + +typedef struct _virNetTLSContext virNetTLSContext; +typedef virNetTLSContext *virNetTLSContextPtr; + +typedef struct _virNetTLSSession virNetTLSSession; +typedef virNetTLSSession *virNetTLSSessionPtr; + + +virNetTLSContextPtr virNetTLSContextNewServerPath(const char *pkipath, + bool tryUserPkiPath, + const char *const*x509dnWhitelist, + bool requireValidCert); + +virNetTLSContextPtr virNetTLSContextNewClientPath(const char *pkipath, + bool tryUserPkiPath, + bool requireValidCert); + +virNetTLSContextPtr virNetTLSContextNewServer(const char *cacert, + const char *cacrl, + const char *cert, + const char *key, + const char *const*x509dnWhitelist, + bool requireValidCert); + +virNetTLSContextPtr virNetTLSContextNewClient(const char *cacert, + const char *cacrl, + const char *cert, + const char *key, + bool requireValidCert); + +void virNetTLSContextRef(virNetTLSContextPtr ctxt); + +int virNetTLSContextCheckCertificate(virNetTLSContextPtr ctxt, + virNetTLSSessionPtr sess); + +void virNetTLSContextFree(virNetTLSContextPtr ctxt); + + +typedef ssize_t (*virNetTLSSessionWriteFunc)(const char *buf, size_t len, + void *opaque); +typedef ssize_t (*virNetTLSSessionReadFunc)(char *buf, size_t len, + void *opaque); + +virNetTLSSessionPtr virNetTLSSessionNew(virNetTLSContextPtr ctxt, + const char *hostname); + +void virNetTLSSessionSetIOCallbacks(virNetTLSSessionPtr sess, + virNetTLSSessionWriteFunc writeFunc, + virNetTLSSessionReadFunc readFunc, + void *opaque); + +void virNetTLSSessionRef(virNetTLSSessionPtr sess); + +ssize_t virNetTLSSessionWrite(virNetTLSSessionPtr sess, + const char *buf, size_t len); +ssize_t virNetTLSSessionRead(virNetTLSSessionPtr sess, + char *buf, size_t len); + +int virNetTLSSessionHandshake(virNetTLSSessionPtr sess); + +typedef enum { + VIR_NET_TLS_HANDSHAKE_COMPLETE, + VIR_NET_TLS_HANDSHAKE_SENDING, + VIR_NET_TLS_HANDSHAKE_RECVING, +} virNetTLSSessionHandshakeStatus; + +virNetTLSSessionHandshakeStatus +virNetTLSSessionGetHandshakeStatus(virNetTLSSessionPtr sess); + +int virNetTLSSessionGetKeySize(virNetTLSSessionPtr sess); + +void virNetTLSSessionFree(virNetTLSSessionPtr sess); + + +#endif -- 1.7.4.4