/* * 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 #include #include #include #include #include #include "gnutls_1_0_compat.h" #include "virnettlscontext.h" #include "memory.h" #include "virterror_internal.h" #include "util.h" #include "logging.h" #include "threads.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 { virMutex lock; int refs; gnutls_certificate_credentials_t x509cred; gnutls_dh_params_t dhParams; bool isServer; bool requireValidCert; const char *const*x509dnWhitelist; }; struct _virNetTLSSession { virMutex lock; int refs; bool handshakeComplete; bool isServer; 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 ATTRIBUTE_UNUSED, const char *str ATTRIBUTE_UNUSED) { VIR_DEBUG("%d %s", level, str); } static int virNetTLSContextCheckCertTimes(gnutls_x509_crt_t cert, const char *certFile, bool isServer, bool isCA) { time_t now; if ((now = time(NULL)) == ((time_t)-1)) { virReportSystemError(errno, "%s", _("cannot get current time")); return -1; } if (gnutls_x509_crt_get_expiration_time(cert) < now) { virNetError(VIR_ERR_SYSTEM_ERROR, (isCA ? _("The CA certificate %s has expired") : (isServer ? _("The server certificate %s has expired") : _("The client certificate %s has expired"))), certFile); return -1; } if (gnutls_x509_crt_get_activation_time(cert) > now) { virNetError(VIR_ERR_SYSTEM_ERROR, (isCA ? _("The CA certificate %s is not yet active") : (isServer ? _("The server certificate %s is not yet active") : _("The client certificate %s is not yet active"))), certFile); return -1; } return 0; } #ifndef GNUTLS_1_0_COMPAT /* * The gnutls_x509_crt_get_basic_constraints function isn't * available in GNUTLS 1.0.x branches. This isn't critical * though, since gnutls_certificate_verify_peers2 will do * pretty much the same check at runtime, so we can just * disable this code */ static int virNetTLSContextCheckCertBasicConstraints(gnutls_x509_crt_t cert, const char *certFile, bool isServer, bool isCA) { int status; status = gnutls_x509_crt_get_basic_constraints(cert, NULL, NULL, NULL); VIR_DEBUG("Cert %s basic constraints %d", certFile, status); if (status > 0) { /* It is a CA cert */ if (!isCA) { virNetError(VIR_ERR_SYSTEM_ERROR, isServer ? _("The certificate %s basic constraints show a CA, but we need one for a server") : _("The certificate %s basic constraints show a CA, but we need one for a client"), certFile); return -1; } } else if (status == 0) { /* It is not a CA cert */ if (isCA) { virNetError(VIR_ERR_SYSTEM_ERROR, _("The certificate %s basic constraints do not show a CA"), certFile); return -1; } } else if (status == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) { /* Missing basicConstraints */ if (isCA) { virNetError(VIR_ERR_SYSTEM_ERROR, _("The certificate %s is missing basic constraints for a CA"), certFile); return -1; } } else { /* General error */ virNetError(VIR_ERR_SYSTEM_ERROR, _("Unable to query certificate %s basic constraints %s"), certFile, gnutls_strerror(status)); return -1; } return 0; } #endif static int virNetTLSContextCheckCertKeyUsage(gnutls_x509_crt_t cert, const char *certFile, bool isCA) { int status; unsigned int usage; unsigned int critical; status = gnutls_x509_crt_get_key_usage(cert, &usage, &critical); VIR_DEBUG("Cert %s key usage status %d usage %d critical %u", certFile, status, usage, critical); if (status < 0) { if (status == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) { usage = isCA ? GNUTLS_KEY_KEY_CERT_SIGN : GNUTLS_KEY_DIGITAL_SIGNATURE|GNUTLS_KEY_KEY_ENCIPHERMENT; } else { virNetError(VIR_ERR_SYSTEM_ERROR, _("Unable to query certificate %s key usage %s"), certFile, gnutls_strerror(status)); return -1; } } if (isCA) { if (!(usage & GNUTLS_KEY_KEY_CERT_SIGN)) { if (critical) { virNetError(VIR_ERR_SYSTEM_ERROR, _("Certificate %s usage does not permit certificate signing"), certFile); return -1; } else { VIR_WARN("Certificate %s usage does not permit certificate signing", certFile); } } } else { if (!(usage & GNUTLS_KEY_DIGITAL_SIGNATURE)) { if (critical) { virNetError(VIR_ERR_SYSTEM_ERROR, _("Certificate %s usage does not permit digital signature"), certFile); return -1; } else { VIR_WARN("Certificate %s usage does not permit digital signature", certFile); } } if (!(usage & GNUTLS_KEY_KEY_ENCIPHERMENT)) { if (critical) { virNetError(VIR_ERR_SYSTEM_ERROR, _("Certificate %s usage does not permit key encipherment"), certFile); return -1; } else { VIR_WARN("Certificate %s usage does not permit key encipherment", certFile); } } } return 0; } static int virNetTLSContextCheckCertKeyPurpose(gnutls_x509_crt_t cert, const char *certFile, bool isServer) { int status; int i; unsigned int purposeCritical; unsigned int critical; char *buffer = NULL; size_t size; bool allowClient = false, allowServer = false; critical = 0; for (i = 0 ; ; i++) { size = 0; status = gnutls_x509_crt_get_key_purpose_oid(cert, i, buffer, &size, NULL); if (status == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) { VIR_DEBUG("No key purpose data available at slot %d", i); /* If there is no data at all, then we must allow client/server to pass */ if (i == 0) allowServer = allowClient = true; break; } if (status != GNUTLS_E_SHORT_MEMORY_BUFFER) { virNetError(VIR_ERR_SYSTEM_ERROR, _("Unable to query certificate %s key purpose %s"), certFile, gnutls_strerror(status)); return -1; } if (VIR_ALLOC_N(buffer, size) < 0) { virReportOOMError(); return -1; } status = gnutls_x509_crt_get_key_purpose_oid(cert, i, buffer, &size, &purposeCritical); if (status < 0) { VIR_FREE(buffer); virNetError(VIR_ERR_SYSTEM_ERROR, _("Unable to query certificate %s key purpose %s"), certFile, gnutls_strerror(status)); return -1; } if (purposeCritical) critical = true; VIR_DEBUG("Key purpose %d %s critical %u", status, buffer, purposeCritical); if (STREQ(buffer, GNUTLS_KP_TLS_WWW_SERVER)) { allowServer = true; } else if (STREQ(buffer, GNUTLS_KP_TLS_WWW_CLIENT)) { allowClient = true; } else if (STRNEQ(buffer, GNUTLS_KP_ANY)) { allowServer = allowClient = true; } VIR_FREE(buffer); } if (isServer) { if (!allowServer) { if (critical) { virNetError(VIR_ERR_SYSTEM_ERROR, _("Certificate %s purpose does not allow use for with a TLS server"), certFile); return -1; } else { VIR_WARN("Certificate %s purpose does not allow use for with a TLS server", certFile); } } } else { if (!allowClient) { if (critical) { virNetError(VIR_ERR_SYSTEM_ERROR, _("Certificate %s purpose does not allow use for with a TLS client"), certFile); return -1; } else { VIR_WARN("Certificate %s purpose does not allow use for with a TLS client", certFile); } } } return 0; } /* Check DN is on tls_allowed_dn_list. */ static int virNetTLSContextCheckCertDNWhitelist(const char *dname, const char *const*wildcards) { 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 virNetTLSContextCheckCertDN(gnutls_x509_crt_t cert, const char *certFile, const char *hostname, const char *dname, const char *const* whitelist) { if (whitelist && dname && virNetTLSContextCheckCertDNWhitelist(dname, whitelist) <= 0) return -1; if (hostname && !gnutls_x509_crt_check_hostname(cert, hostname)) { virNetError(VIR_ERR_RPC, _("Certificate %s owner does not match the hostname %s"), certFile, hostname); return -1; } return 0; } static int virNetTLSContextCheckCert(gnutls_x509_crt_t cert, const char *certFile, bool isServer, bool isCA) { if (virNetTLSContextCheckCertTimes(cert, certFile, isServer, isCA) < 0) return -1; #ifndef GNUTLS_1_0_COMPAT if (virNetTLSContextCheckCertBasicConstraints(cert, certFile, isServer, isCA) < 0) return -1; #endif if (virNetTLSContextCheckCertKeyUsage(cert, certFile, isCA) < 0) return -1; if (!isCA && virNetTLSContextCheckCertKeyPurpose(cert, certFile, isServer) < 0) return -1; return 0; } static int virNetTLSContextCheckCertPair(gnutls_x509_crt_t cert, const char *certFile, gnutls_x509_crt_t cacert, const char *cacertFile, bool isServer) { unsigned int status; if (gnutls_x509_crt_list_verify(&cert, 1, &cacert, 1, NULL, 0, 0, &status) < 0) { virNetError(VIR_ERR_SYSTEM_ERROR, isServer ? _("Unable to verify server certificate %s against CA certificate %s") : _("Unable to verify client certificate %s against CA certificate %s"), certFile, cacertFile); return -1; } 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, _("Our own certificate %s failed validation against %s: %s"), certFile, cacertFile, reason); return -1; } return 0; } static gnutls_x509_crt_t virNetTLSContextLoadCertFromFile(const char *certFile, bool isServer, bool isCA ATTRIBUTE_UNUSED) { gnutls_datum_t data; gnutls_x509_crt_t cert = NULL; char *buf = NULL; int ret = -1; VIR_DEBUG("isServer %d isCA %d certFile %s", isServer, isCA, certFile); if (gnutls_x509_crt_init(&cert) < 0) { virNetError(VIR_ERR_SYSTEM_ERROR, "%s", _("Unable to initialize certificate")); goto cleanup; } if (virFileReadAll(certFile, (1<<16), &buf) < 0) goto cleanup; data.data = (unsigned char *)buf; data.size = strlen(buf); if (gnutls_x509_crt_import(cert, &data, GNUTLS_X509_FMT_PEM) < 0) { virNetError(VIR_ERR_SYSTEM_ERROR, isServer ? _("Unable to import server certificate %s") : _("Unable to import client certificate %s"), certFile); goto cleanup; } ret = 0; cleanup: if (ret != 0) { gnutls_x509_crt_deinit(cert); cert = NULL; } VIR_FREE(buf); return cert; } static int virNetTLSContextSanityCheckCredentials(bool isServer, const char *cacertFile, const char *certFile) { gnutls_x509_crt_t cert = NULL; gnutls_x509_crt_t cacert = NULL; int ret = -1; if ((access(certFile, R_OK) == 0) && !(cert = virNetTLSContextLoadCertFromFile(certFile, isServer, false))) goto cleanup; if ((access(cacertFile, R_OK) == 0) && !(cacert = virNetTLSContextLoadCertFromFile(cacertFile, isServer, false))) goto cleanup; if (cert && virNetTLSContextCheckCert(cert, certFile, isServer, false) < 0) goto cleanup; if (cacert && virNetTLSContextCheckCert(cacert, cacertFile, isServer, true) < 0) goto cleanup; if (cert && cacert && virNetTLSContextCheckCertPair(cert, certFile, cacert, cacertFile, isServer) < 0) goto cleanup; ret = 0; cleanup: if (cert) gnutls_x509_crt_deinit(cert); if (cacert) gnutls_x509_crt_deinit(cacert); return ret; } 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 sanityCheckCert, bool requireValidCert, bool isServer) { virNetTLSContextPtr ctxt; char *gnutlsdebug; int err; VIR_DEBUG("cacert=%s cacrl=%s cert=%s key=%s sanityCheckCert=%d requireValid=%d isServer=%d", cacert, NULLSTR(cacrl), cert, key, sanityCheckCert, requireValidCert, isServer); if (VIR_ALLOC(ctxt) < 0) { virReportOOMError(); return NULL; } if (virMutexInit(&ctxt->lock) < 0) { virNetError(VIR_ERR_INTERNAL_ERROR, "%s", _("Failed to initialized mutex")); VIR_FREE(ctxt); return NULL; } ctxt->refs = 1; 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 (sanityCheckCert && virNetTLSContextSanityCheckCredentials(isServer, cacert, cert) < 0) 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 sanityCheckCert, bool requireValidCert, bool isServer) { char *cacert = NULL, *cacrl = NULL, *key = NULL, *cert = NULL; virNetTLSContextPtr ctxt = NULL; if (virNetTLSContextLocateCredentials(pkipath, tryUserPkiPath, isServer, &cacert, &cacrl, &cert, &key) < 0) return NULL; ctxt = virNetTLSContextNew(cacert, cacrl, cert, key, x509dnWhitelist, sanityCheckCert, 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 sanityCheckCert, bool requireValidCert) { return virNetTLSContextNewPath(pkipath, tryUserPkiPath, x509dnWhitelist, sanityCheckCert, requireValidCert, true); } virNetTLSContextPtr virNetTLSContextNewClientPath(const char *pkipath, bool tryUserPkiPath, bool sanityCheckCert, bool requireValidCert) { return virNetTLSContextNewPath(pkipath, tryUserPkiPath, NULL, sanityCheckCert, requireValidCert, false); } virNetTLSContextPtr virNetTLSContextNewServer(const char *cacert, const char *cacrl, const char *cert, const char *key, const char *const*x509dnWhitelist, bool sanityCheckCert, bool requireValidCert) { return virNetTLSContextNew(cacert, cacrl, cert, key, x509dnWhitelist, sanityCheckCert, requireValidCert, true); } virNetTLSContextPtr virNetTLSContextNewClient(const char *cacert, const char *cacrl, const char *cert, const char *key, bool sanityCheckCert, bool requireValidCert) { return virNetTLSContextNew(cacert, cacrl, cert, key, NULL, sanityCheckCert, requireValidCert, false); } void virNetTLSContextRef(virNetTLSContextPtr ctxt) { ctxt->refs++; } static int virNetTLSContextValidCertificate(virNetTLSContextPtr ctxt, virNetTLSSessionPtr sess) { int ret; unsigned int status; const gnutls_datum_t *certs; unsigned int nCerts, i; char dname[256]; size_t dnamesize = sizeof(dname); memset(dname, 0, dnamesize); 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 (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 (virNetTLSContextCheckCertTimes(cert, "[session]", sess->isServer, i > 0) < 0) { gnutls_x509_crt_deinit(cert); goto authdeny; } if (i == 0) { ret = gnutls_x509_crt_get_dn(cert, dname, &dnamesize); if (ret != 0) { virNetError(VIR_ERR_SYSTEM_ERROR, _("Failed to get certificate %s distinguished name: %s"), "[session]", gnutls_strerror(ret)); goto authfail; } VIR_DEBUG("Peer DN is %s", dname); if (virNetTLSContextCheckCertDN(cert, "[session]", sess->hostname, dname, ctxt->x509dnWhitelist) < 0) { gnutls_x509_crt_deinit(cert); goto authdeny; } /* !sess->isServer, since on the client, we're validating the * server's cert, and on the server, the client's cert */ #ifndef GNUTLS_1_0_COMPAT if (virNetTLSContextCheckCertBasicConstraints(cert, "[session]", !sess->isServer, false) < 0) { gnutls_x509_crt_deinit(cert); goto authdeny; } #endif if (virNetTLSContextCheckCertKeyUsage(cert, "[session]", false) < 0) { gnutls_x509_crt_deinit(cert); goto authdeny; } /* !sess->isServer - as above */ if (virNetTLSContextCheckCertKeyPurpose(cert, "[session]", !sess->isServer) < 0) { gnutls_x509_crt_deinit(cert); goto authdeny; } } gnutls_x509_crt_deinit(cert); } #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) { int ret = -1; virMutexLock(&ctxt->lock); virMutexLock(&sess->lock); if (virNetTLSContextValidCertificate(ctxt, sess) < 0) { virErrorPtr err = virGetLastError(); VIR_WARN("Certificate check failed %s", err && err->message ? err->message : ""); if (ctxt->requireValidCert) { virNetError(VIR_ERR_AUTH_FAILED, "%s", _("Failed to verify peer's certificate")); goto cleanup; } virResetLastError(); VIR_INFO("Ignoring bad certificate at user request"); } ret = 0; cleanup: virMutexUnlock(&ctxt->lock); virMutexUnlock(&sess->lock); return ret; } void virNetTLSContextFree(virNetTLSContextPtr ctxt) { if (!ctxt) return; virMutexLock(&ctxt->lock); ctxt->refs--; if (ctxt->refs > 0) { virMutexUnlock(&ctxt->lock); return; } gnutls_dh_params_deinit(ctxt->dhParams); gnutls_certificate_free_credentials(ctxt->x509cred); virMutexUnlock(&ctxt->lock); virMutexDestroy(&ctxt->lock); 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 write 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; VIR_DEBUG("ctxt=%p hostname=%s isServer=%d", ctxt, NULLSTR(hostname), ctxt->isServer); if (VIR_ALLOC(sess) < 0) { virReportOOMError(); return NULL; } if (virMutexInit(&sess->lock) < 0) { virNetError(VIR_ERR_INTERNAL_ERROR, "%s", _("Failed to initialized mutex")); VIR_FREE(sess); 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) { 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); sess->isServer = ctxt->isServer; return sess; error: virNetTLSSessionFree(sess); return NULL; } void virNetTLSSessionRef(virNetTLSSessionPtr sess) { virMutexLock(&sess->lock); sess->refs++; virMutexUnlock(&sess->lock); } void virNetTLSSessionSetIOCallbacks(virNetTLSSessionPtr sess, virNetTLSSessionWriteFunc writeFunc, virNetTLSSessionReadFunc readFunc, void *opaque) { virMutexLock(&sess->lock); sess->writeFunc = writeFunc; sess->readFunc = readFunc; sess->opaque = opaque; virMutexUnlock(&sess->lock); } ssize_t virNetTLSSessionWrite(virNetTLSSessionPtr sess, const char *buf, size_t len) { ssize_t ret; virMutexLock(&sess->lock); ret = gnutls_record_send(sess->session, buf, len); if (ret >= 0) goto cleanup; switch (ret) { case GNUTLS_E_AGAIN: errno = EAGAIN; break; case GNUTLS_E_INTERRUPTED: errno = EINTR; break; case GNUTLS_E_UNEXPECTED_PACKET_LENGTH: errno = ENOMSG; break; default: errno = EIO; break; } ret = -1; cleanup: virMutexUnlock(&sess->lock); return ret; } ssize_t virNetTLSSessionRead(virNetTLSSessionPtr sess, char *buf, size_t len) { ssize_t ret; virMutexLock(&sess->lock); ret = gnutls_record_recv(sess->session, buf, len); if (ret >= 0) goto cleanup; switch (ret) { case GNUTLS_E_AGAIN: errno = EAGAIN; break; case GNUTLS_E_INTERRUPTED: errno = EINTR; break; default: errno = EIO; break; } ret = -1; cleanup: virMutexUnlock(&sess->lock); return ret; } int virNetTLSSessionHandshake(virNetTLSSessionPtr sess) { int ret; VIR_DEBUG("sess=%p", sess); virMutexLock(&sess->lock); ret = gnutls_handshake(sess->session); VIR_DEBUG("Ret=%d", ret); if (ret == 0) { sess->handshakeComplete = true; VIR_DEBUG("Handshake is complete"); goto cleanup; } if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) { ret = 1; goto cleanup; } #if 0 PROBE(CLIENT_TLS_FAIL, "fd=%d", virNetServerClientGetFD(client)); #endif virNetError(VIR_ERR_AUTH_FAILED, _("TLS handshake failed %s"), gnutls_strerror(ret)); ret = -1; cleanup: virMutexUnlock(&sess->lock); return ret; } virNetTLSSessionHandshakeStatus virNetTLSSessionGetHandshakeStatus(virNetTLSSessionPtr sess) { virNetTLSSessionHandshakeStatus ret; virMutexLock(&sess->lock); if (sess->handshakeComplete) ret = VIR_NET_TLS_HANDSHAKE_COMPLETE; else if (gnutls_record_get_direction(sess->session) == 0) ret = VIR_NET_TLS_HANDSHAKE_RECVING; else ret = VIR_NET_TLS_HANDSHAKE_SENDING; virMutexUnlock(&sess->lock); return ret; } int virNetTLSSessionGetKeySize(virNetTLSSessionPtr sess) { gnutls_cipher_algorithm_t cipher; int ssf; virMutexLock(&sess->lock); 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")); ssf = -1; goto cleanup; } cleanup: virMutexUnlock(&sess->lock); return ssf; } void virNetTLSSessionFree(virNetTLSSessionPtr sess) { if (!sess) return; virMutexLock(&sess->lock); sess->refs--; if (sess->refs > 0) { virMutexUnlock(&sess->lock); return; } VIR_FREE(sess->hostname); gnutls_deinit(sess->session); virMutexUnlock(&sess->lock); virMutexDestroy(&sess->lock); VIR_FREE(sess); } /* * This function MUST be called before any * virNetTLS* because it initializes * underlying GnuTLS library. According to * it's documentation, it's safe to be called * many times, but is not thread safe. Each * call SHOULD be later followed by * virNetTLSContextDeinit. */ void virNetTLSInit(void) { gnutls_global_init(); }