[libvirt] [PATCH 04/10] Generic module for handling SASL authentication & encryption

This provides two modules for handling SASL * virNetSASLContext provides the process-wide state, currently just a whitelist of usernames on the server and a one time library init call * virNetTLSSession provides the per-connection state, ie the SASL session itself. This also include APIs for providing data encryption/decryption once the session is established * src/Makefile.am: Add to libvirt-net-rpc.la * src/rpc/virnetsaslcontext.c, src/rpc/virnetsaslcontext.h: Generic SASL handling code --- po/POTFILES.in | 1 + src/Makefile.am | 9 + src/rpc/virnetsaslcontext.c | 606 +++++++++++++++++++++++++++++++++++++++++++ src/rpc/virnetsaslcontext.h | 120 +++++++++ 4 files changed, 736 insertions(+), 0 deletions(-) create mode 100644 src/rpc/virnetsaslcontext.c create mode 100644 src/rpc/virnetsaslcontext.h diff --git a/po/POTFILES.in b/po/POTFILES.in index 30c69d1..53d63a8 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -65,6 +65,7 @@ src/qemu/qemu_monitor_text.c src/qemu/qemu_process.c src/remote/remote_driver.c src/rpc/virnetmessage.c +src/rpc/virnetsaslcontext.c src/rpc/virnetsocket.c src/rpc/virnettlscontext.c src/secret/secret_driver.c diff --git a/src/Makefile.am b/src/Makefile.am index 351bf2a..5d20d63 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -1206,11 +1206,20 @@ libvirt_net_rpc_la_SOURCES = \ rpc/virnetprotocol.h rpc/virnetprotocol.c \ rpc/virnetsocket.h rpc/virnetsocket.c \ rpc/virnettlscontext.h rpc/virnettlscontext.c +if HAVE_SASL +libvirt_net_rpc_la_SOURCES += \ + rpc/virnetsaslcontext.h rpc/virnetsaslcontext.c +else +EXTRA_DIST += \ + rpc/virnetsaslcontext.h rpc/virnetsaslcontext.c +endif libvirt_net_rpc_la_CFLAGS = \ $(GNUTLS_CFLAGS) \ + $(SASL_CFLAGS) \ $(AM_CFLAGS) libvirt_net_rpc_la_LDFLAGS = \ $(GNUTLS_LIBS) \ + $(SASL_LIBS) \ $(AM_LDFLAGS) \ $(CYGWIN_EXTRA_LDFLAGS) \ $(MINGW_EXTRA_LDFLAGS) diff --git a/src/rpc/virnetsaslcontext.c b/src/rpc/virnetsaslcontext.c new file mode 100644 index 0000000..c84cd6e --- /dev/null +++ b/src/rpc/virnetsaslcontext.c @@ -0,0 +1,606 @@ +/* + * virnetsaslcontext.c: SASL encryption/auth handling + * + * Copyright (C) 2010 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> + +#ifdef HAVE_FNMATCH_H +# include <fnmatch.h> +#endif + +#include "virnetsaslcontext.h" +#include "virnetmessage.h" + +#include "virterror_internal.h" +#include "memory.h" +#include "logging.h" + +#define VIR_FROM_THIS VIR_FROM_RPC + +#define virNetError(code, ...) \ + virReportErrorHelper(NULL, VIR_FROM_RPC, code, __FILE__, \ + __FUNCTION__, __LINE__, __VA_ARGS__) + + +struct _virNetSASLContext { + const char *const*usernameWhitelist; + int refs; +}; + +struct _virNetSASLSession { + sasl_conn_t *conn; + int refs; + size_t maxbufsize; +}; + + +virNetSASLContextPtr virNetSASLContextNewClient(void) +{ + virNetSASLContextPtr ctxt; + int err; + + err = sasl_client_init(NULL); + if (err != SASL_OK) { + virNetError(VIR_ERR_AUTH_FAILED, + _("failed to initialize SASL library: %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + return NULL; + } + + if (VIR_ALLOC(ctxt) < 0) { + virReportOOMError(); + return NULL; + } + + ctxt->refs = 1; + + return ctxt; +} + +virNetSASLContextPtr virNetSASLContextNewServer(const char *const*usernameWhitelist) +{ + virNetSASLContextPtr ctxt; + int err; + + err = sasl_server_init(NULL, "libvirt"); + if (err != SASL_OK) { + virNetError(VIR_ERR_AUTH_FAILED, + _("failed to initialize SASL library: %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + return NULL; + } + + if (VIR_ALLOC(ctxt) < 0) { + virReportOOMError(); + return NULL; + } + + ctxt->usernameWhitelist = usernameWhitelist; + ctxt->refs = 1; + + return ctxt; +} + +int virNetSASLContextCheckIdentity(virNetSASLContextPtr ctxt, + const char *identity) +{ + const char *const*wildcards; + + /* If the list is not set, allow any DN. */ + wildcards = ctxt->usernameWhitelist; + if (!wildcards) + return 1; /* No ACL, allow all */ + + while (*wildcards) { +#if HAVE_FNMATCH_H + int ret = fnmatch (*wildcards, identity, 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; + } +#else + if (STREQ(*wildcards, identity)) + return 1; +#endif + + wildcards++; + } + + /* Denied */ + VIR_ERROR(_("SASL client %s not allowed in whitelist"), identity); + + /* This is the most common error: make it informative. */ + virNetError(VIR_ERR_SYSTEM_ERROR, "%s", + _("Client's username is not on the list of allowed clients")); + return 0; +} + + +void virNetSASLContextRef(virNetSASLContextPtr ctxt) +{ + ctxt->refs++; +} + +void virNetSASLContextFree(virNetSASLContextPtr ctxt) +{ + if (!ctxt) + return; + + ctxt->refs--; + if (ctxt->refs > 0) + return; + + VIR_FREE(ctxt); +} + +virNetSASLSessionPtr virNetSASLSessionNewClient(virNetSASLContextPtr ctxt ATTRIBUTE_UNUSED, + const char *service, + const char *hostname, + const char *localAddr, + const char *remoteAddr, + const sasl_callback_t *cbs) +{ + virNetSASLSessionPtr sasl = NULL; + int err; + + if (VIR_ALLOC(sasl) < 0) { + virReportOOMError(); + goto cleanup; + } + + sasl->refs = 1; + /* Arbitrary size for amount of data we can encode in a single block */ + sasl->maxbufsize = 1 << 16; + + err = sasl_client_new(service, + hostname, + localAddr, + remoteAddr, + cbs, + SASL_SUCCESS_DATA, + &sasl->conn); + if (err != SASL_OK) { + virNetError(VIR_ERR_AUTH_FAILED, + _("Failed to create SASL client context: %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + goto cleanup; + } + + return sasl; + +cleanup: + virNetSASLSessionFree(sasl); + return NULL; +} + +virNetSASLSessionPtr virNetSASLSessionNewServer(virNetSASLContextPtr ctxt ATTRIBUTE_UNUSED, + const char *service, + const char *localAddr, + const char *remoteAddr) +{ + virNetSASLSessionPtr sasl = NULL; + int err; + + if (VIR_ALLOC(sasl) < 0) { + virReportOOMError(); + goto cleanup; + } + + sasl->refs = 1; + /* Arbitrary size for amount of data we can encode in a single block */ + sasl->maxbufsize = 1 << 16; + + err = sasl_server_new(service, + NULL, + NULL, + localAddr, + remoteAddr, + NULL, + SASL_SUCCESS_DATA, + &sasl->conn); + if (err != SASL_OK) { + virNetError(VIR_ERR_AUTH_FAILED, + _("Failed to create SASL client context: %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + goto cleanup; + } + + return sasl; + +cleanup: + virNetSASLSessionFree(sasl); + return NULL; +} + +void virNetSASLSessionRef(virNetSASLSessionPtr sasl) +{ + sasl->refs++; +} + +int virNetSASLSessionExtKeySize(virNetSASLSessionPtr sasl, + int ssf) +{ + int err; + + err = sasl_setprop(sasl->conn, SASL_SSF_EXTERNAL, &ssf); + if (err != SASL_OK) { + virNetError(VIR_ERR_INTERNAL_ERROR, + _("cannot set external SSF %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + return -1; + } + return 0; +} + +const char *virNetSASLSessionGetIdentity(virNetSASLSessionPtr sasl) +{ + const void *val; + int err; + + err = sasl_getprop(sasl->conn, SASL_USERNAME, &val); + if (err != SASL_OK) { + virNetError(VIR_ERR_AUTH_FAILED, + _("cannot query SASL username on connection %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + return NULL; + } + if (val == NULL) { + virNetError(VIR_ERR_AUTH_FAILED, + _("no client username was found")); + return NULL; + } + VIR_DEBUG("SASL client username %s", (const char *)val); + + return (const char*)val; +} + + +int virNetSASLSessionGetKeySize(virNetSASLSessionPtr sasl) +{ + int err; + int ssf; + const void *val; + err = sasl_getprop(sasl->conn, SASL_SSF, &val); + if (err != SASL_OK) { + virNetError(VIR_ERR_AUTH_FAILED, + _("cannot query SASL ssf on connection %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + return -1; + } + ssf = *(const int *)val; + return ssf; +} + +int virNetSASLSessionSecProps(virNetSASLSessionPtr sasl, + int minSSF, + int maxSSF, + bool allowAnonymous) +{ + sasl_security_properties_t secprops; + int err; + + VIR_DEBUG("minSSF=%d maxSSF=%d allowAnonymous=%d maxbufsize=%zu", + minSSF, maxSSF, allowAnonymous, sasl->maxbufsize); + + memset(&secprops, 0, sizeof secprops); + + secprops.min_ssf = minSSF; + secprops.max_ssf = maxSSF; + secprops.maxbufsize = sasl->maxbufsize; + secprops.security_flags = allowAnonymous ? 0 : + SASL_SEC_NOANONYMOUS | SASL_SEC_NOPLAINTEXT; + + err = sasl_setprop(sasl->conn, SASL_SEC_PROPS, &secprops); + if (err != SASL_OK) { + virNetError(VIR_ERR_INTERNAL_ERROR, + _("cannot set security props %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + return -1; + } + + return 0; +} + + +static int virNetSASLSessionUpdateBufSize(virNetSASLSessionPtr sasl) +{ + unsigned *maxbufsize; + int err; + + err = sasl_getprop(sasl->conn, SASL_MAXOUTBUF, (const void **)&maxbufsize); + if (err != SASL_OK) { + virNetError(VIR_ERR_INTERNAL_ERROR, + _("cannot get security props %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + return -1; + } + + VIR_DEBUG("Negotiated bufsize is %u vs requested size %zu", + *maxbufsize, sasl->maxbufsize); + sasl->maxbufsize = *maxbufsize; + return 0; +} + +char *virNetSASLSessionListMechanisms(virNetSASLSessionPtr sasl) +{ + const char *mechlist; + char *ret; + int err; + + err = sasl_listmech(sasl->conn, + NULL, /* Don't need to set user */ + "", /* Prefix */ + ",", /* Separator */ + "", /* Suffix */ + &mechlist, + NULL, + NULL); + if (err != SASL_OK) { + virNetError(VIR_ERR_INTERNAL_ERROR, + _("cannot list SASL mechanisms %d (%s)"), + err, sasl_errdetail(sasl->conn)); + return NULL; + } + if (!(ret = strdup(mechlist))) { + virReportOOMError(); + return NULL; + } + return ret; +} + + +int virNetSASLSessionClientStart(virNetSASLSessionPtr sasl, + const char *mechlist, + sasl_interact_t **prompt_need, + const char **clientout, + size_t *clientoutlen, + const char **mech) +{ + unsigned outlen = 0; + + VIR_DEBUG("sasl=%p mechlist=%s prompt_need=%p clientout=%p clientoutlen=%p mech=%p", + sasl, mechlist, prompt_need, clientout, clientoutlen, mech); + + int err = sasl_client_start(sasl->conn, + mechlist, + prompt_need, + clientout, + &outlen, + mech); + + *clientoutlen = outlen; + + switch (err) { + case SASL_OK: + if (virNetSASLSessionUpdateBufSize(sasl) < 0) + return -1; + return VIR_NET_SASL_COMPLETE; + case SASL_CONTINUE: + return VIR_NET_SASL_CONTINUE; + case SASL_INTERACT: + return VIR_NET_SASL_INTERACT; + + default: + virNetError(VIR_ERR_AUTH_FAILED, + _("Failed to start SASL negotiation: %d (%s)"), + err, sasl_errdetail(sasl->conn)); + return -1; + } +} + + +int virNetSASLSessionClientStep(virNetSASLSessionPtr sasl, + const char *serverin, + size_t serverinlen, + sasl_interact_t **prompt_need, + const char **clientout, + size_t *clientoutlen) +{ + unsigned inlen = serverinlen; + unsigned outlen = 0; + + VIR_DEBUG("sasl=%p serverin=%s serverinlen=%zu prompt_need=%p clientout=%p clientoutlen=%p", + sasl, serverin, serverinlen, prompt_need, clientout, clientoutlen); + + int err = sasl_client_step(sasl->conn, + serverin, + inlen, + prompt_need, + clientout, + &outlen); + *clientoutlen = outlen; + + switch (err) { + case SASL_OK: + if (virNetSASLSessionUpdateBufSize(sasl) < 0) + return -1; + return VIR_NET_SASL_COMPLETE; + case SASL_CONTINUE: + return VIR_NET_SASL_CONTINUE; + case SASL_INTERACT: + return VIR_NET_SASL_INTERACT; + + default: + virNetError(VIR_ERR_AUTH_FAILED, + _("Failed to step SASL negotiation: %d (%s)"), + err, sasl_errdetail(sasl->conn)); + return -1; + } +} + +int virNetSASLSessionServerStart(virNetSASLSessionPtr sasl, + const char *mechname, + const char *clientin, + size_t clientinlen, + const char **serverout, + size_t *serveroutlen) +{ + unsigned inlen = clientinlen; + unsigned outlen = 0; + int err = sasl_server_start(sasl->conn, + mechname, + clientin, + inlen, + serverout, + &outlen); + + *serveroutlen = outlen; + + switch (err) { + case SASL_OK: + if (virNetSASLSessionUpdateBufSize(sasl) < 0) + return -1; + return VIR_NET_SASL_COMPLETE; + case SASL_CONTINUE: + return VIR_NET_SASL_CONTINUE; + case SASL_INTERACT: + return VIR_NET_SASL_INTERACT; + + default: + virNetError(VIR_ERR_AUTH_FAILED, + _("Failed to start SASL negotiation: %d (%s)"), + err, sasl_errdetail(sasl->conn)); + return -1; + } +} + + +int virNetSASLSessionServerStep(virNetSASLSessionPtr sasl, + const char *clientin, + size_t clientinlen, + const char **serverout, + size_t *serveroutlen) +{ + unsigned inlen = clientinlen; + unsigned outlen = 0; + + int err = sasl_server_step(sasl->conn, + clientin, + inlen, + serverout, + &outlen); + + *serveroutlen = outlen; + + switch (err) { + case SASL_OK: + if (virNetSASLSessionUpdateBufSize(sasl) < 0) + return -1; + return VIR_NET_SASL_COMPLETE; + case SASL_CONTINUE: + return VIR_NET_SASL_CONTINUE; + case SASL_INTERACT: + return VIR_NET_SASL_INTERACT; + + default: + virNetError(VIR_ERR_AUTH_FAILED, + _("Failed to start SASL negotiation: %d (%s)"), + err, sasl_errdetail(sasl->conn)); + return -1; + } +} + +size_t virNetSASLSessionGetMaxBufSize(virNetSASLSessionPtr sasl) +{ + return sasl->maxbufsize; +} + +ssize_t virNetSASLSessionEncode(virNetSASLSessionPtr sasl, + const char *input, + size_t inputLen, + const char **output, + size_t *outputlen) +{ + unsigned inlen = inputLen; + unsigned outlen = 0; + int err; + + if (inputLen > sasl->maxbufsize) { + virReportSystemError(EINVAL, + _("SASL data length %zu too long, max %zu"), + inputLen, sasl->maxbufsize); + return -1; + } + + err = sasl_encode(sasl->conn, + input, + inlen, + output, + &outlen); + *outputlen = outlen; + + if (err != SASL_OK) { + virNetError(VIR_ERR_INTERNAL_ERROR, + _("failed to encode SASL data: %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + return -1; + } + return 0; +} + +ssize_t virNetSASLSessionDecode(virNetSASLSessionPtr sasl, + const char *input, + size_t inputLen, + const char **output, + size_t *outputlen) +{ + unsigned inlen = inputLen; + unsigned outlen = 0; + int err; + + if (inputLen > sasl->maxbufsize) { + virReportSystemError(EINVAL, + _("SASL data length %zu too long, max %zu"), + inputLen, sasl->maxbufsize); + return -1; + } + + err = sasl_decode(sasl->conn, + input, + inlen, + output, + &outlen); + *outputlen = outlen; + if (err != SASL_OK) { + virNetError(VIR_ERR_INTERNAL_ERROR, + _("failed to decode SASL data: %d (%s)"), + err, sasl_errstring(err, NULL, NULL)); + return -1; + } + return 0; +} + +void virNetSASLSessionFree(virNetSASLSessionPtr sasl) +{ + if (!sasl) + return; + + sasl->refs--; + if (sasl->refs > 0) + return; + + if (sasl->conn) + sasl_dispose(&sasl->conn); + + VIR_FREE(sasl); +} diff --git a/src/rpc/virnetsaslcontext.h b/src/rpc/virnetsaslcontext.h new file mode 100644 index 0000000..1ec6451 --- /dev/null +++ b/src/rpc/virnetsaslcontext.h @@ -0,0 +1,120 @@ +/* + * virnetsaslcontext.h: SASL encryption/auth handling + * + * Copyright (C) 2010 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_CLIENT_SASL_CONTEXT_H__ +# define __VIR_NET_CLIENT_SASL_CONTEXT_H__ + +# include <sasl/sasl.h> + +# include <stdbool.h> +# include <sys/types.h> + +typedef struct _virNetSASLContext virNetSASLContext; +typedef virNetSASLContext *virNetSASLContextPtr; + +typedef struct _virNetSASLSession virNetSASLSession; +typedef virNetSASLSession *virNetSASLSessionPtr; + +enum { + VIR_NET_SASL_COMPLETE, + VIR_NET_SASL_CONTINUE, + VIR_NET_SASL_INTERACT, +}; + +virNetSASLContextPtr virNetSASLContextNewClient(void); +virNetSASLContextPtr virNetSASLContextNewServer(const char *const*usernameWhitelist); + +int virNetSASLContextCheckIdentity(virNetSASLContextPtr ctxt, + const char *identity); + +void virNetSASLContextRef(virNetSASLContextPtr sasl); +void virNetSASLContextFree(virNetSASLContextPtr sasl); + +virNetSASLSessionPtr virNetSASLSessionNewClient(virNetSASLContextPtr ctxt, + const char *service, + const char *hostname, + const char *localAddr, + const char *remoteAddr, + const sasl_callback_t *cbs); +virNetSASLSessionPtr virNetSASLSessionNewServer(virNetSASLContextPtr ctxt, + const char *service, + const char *localAddr, + const char *remoteAddr); + +char *virNetSASLSessionListMechanisms(virNetSASLSessionPtr sasl); + +void virNetSASLSessionRef(virNetSASLSessionPtr sasl); + +int virNetSASLSessionExtKeySize(virNetSASLSessionPtr sasl, + int ssf); + +int virNetSASLSessionGetKeySize(virNetSASLSessionPtr sasl); + +const char *virNetSASLSessionGetIdentity(virNetSASLSessionPtr sasl); + +int virNetSASLSessionSecProps(virNetSASLSessionPtr sasl, + int minSSF, + int maxSSF, + bool allowAnonymous); + +int virNetSASLSessionClientStart(virNetSASLSessionPtr sasl, + const char *mechlist, + sasl_interact_t **prompt_need, + const char **clientout, + size_t *clientoutlen, + const char **mech); + +int virNetSASLSessionClientStep(virNetSASLSessionPtr sasl, + const char *serverin, + size_t serverinlen, + sasl_interact_t **prompt_need, + const char **clientout, + size_t *clientoutlen); + +int virNetSASLSessionServerStart(virNetSASLSessionPtr sasl, + const char *mechname, + const char *clientin, + size_t clientinlen, + const char **serverout, + size_t *serveroutlen); + +int virNetSASLSessionServerStep(virNetSASLSessionPtr sasl, + const char *clientin, + size_t clientinlen, + const char **serverout, + size_t *serveroutlen); + +size_t virNetSASLSessionGetMaxBufSize(virNetSASLSessionPtr sasl); + +ssize_t virNetSASLSessionEncode(virNetSASLSessionPtr sasl, + const char *input, + size_t inputLen, + const char **output, + size_t *outputlen); + +ssize_t virNetSASLSessionDecode(virNetSASLSessionPtr sasl, + const char *input, + size_t inputLen, + const char **output, + size_t *outputlen); + +void virNetSASLSessionFree(virNetSASLSessionPtr sasl); + +#endif /* __VIR_NET_CLIENT_SASL_CONTEXT_H__ */ -- 1.7.4