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spice/server/reds-stream.c
Frediano Ziglio ba175f9be1 channel: add interface parameters to SpiceCoreInterfaceInternal 
This patch and previous ones want to solve the problem of not having a
context in SpiceCoreInterface. SpiceCoreInterface defines a set of
callbacks to handle events in spice-server. These callbacks allow to
handle timers, watch for file descriptors and send channel events.
All these callbacks do not accept a context (usually in C passed as a
void* parameter) so it is hard for them to differentiate the interface
specified.
Unfortunately this structure is used even internally from different
contexts for instance every RedWorker thread has a different context. To
solve this issue some workarounds are used. Currently for timers a variable
depending on the current thread is used while for watches the opaque
parameter to pass to the event callback is used as it currently points just
to RedChannelClient structure.  This however imposes some implicit
maintainance problem in the future. What happens for instance if for some
reason a timer is registered during worker initialization, run in another
thread? What if we decide to register a file descriptor callback for
something not a RedChannelClient?  Could be that the program will run
without any issue till some bytes change and weird things could happen.

The implementation of this solution is done implementing an internal "core"
interface that has context specific and use it to differentiate the
context instead of relying on some other, hard to maintain, detail. Then an
adapter structure (name inpired to the adapter pattern) will provide the
internal core interface using the external, public, definition (in the
future this technique can be used to extend the external interface without
breaking the ABI).

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
Acked-by: Christophe Fergeau <cfergeau@redhat.com>
2016-01-11 16:40:17 +00:00

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/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
Copyright (C) 2009, 2013 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, see <http://www.gnu.org/licenses/>.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "main-dispatcher.h"
#include "red-common.h"
#include "reds-stream.h"
#include "common/log.h"
#include <errno.h>
#include <netdb.h>
#include <unistd.h>
#include <sys/socket.h>
#include <glib.h>
#include <openssl/err.h>
struct AsyncRead {
RedsStream *stream;
void *opaque;
uint8_t *now;
uint8_t *end;
AsyncReadDone done;
AsyncReadError error;
};
typedef struct AsyncRead AsyncRead;
extern SpiceCoreInterfaceInternal *core;
#if HAVE_SASL
#include <sasl/sasl.h>
typedef struct RedsSASL {
sasl_conn_t *conn;
/* If we want to negotiate an SSF layer with client */
int wantSSF :1;
/* If we are now running the SSF layer */
int runSSF :1;
/*
* Buffering encoded data to allow more clear data
* to be stuffed onto the output buffer
*/
const uint8_t *encoded;
unsigned int encodedLength;
unsigned int encodedOffset;
SpiceBuffer inbuffer;
char *username;
char *mechlist;
char *mechname;
/* temporary data during authentication */
unsigned int len;
char *data;
} RedsSASL;
#endif
struct RedsStreamPrivate {
SSL *ssl;
#if HAVE_SASL
RedsSASL sasl;
#endif
AsyncRead async_read;
/* life time of info:
* allocated when creating RedsStream.
* deallocated when main_dispatcher handles the SPICE_CHANNEL_EVENT_DISCONNECTED
* event, either from same thread or by call back from main thread. */
SpiceChannelEventInfo* info;
ssize_t (*read)(RedsStream *s, void *buf, size_t nbyte);
ssize_t (*write)(RedsStream *s, const void *buf, size_t nbyte);
ssize_t (*writev)(RedsStream *s, const struct iovec *iov, int iovcnt);
};
static ssize_t stream_write_cb(RedsStream *s, const void *buf, size_t size)
{
return write(s->socket, buf, size);
}
static ssize_t stream_writev_cb(RedsStream *s, const struct iovec *iov, int iovcnt)
{
ssize_t ret = 0;
do {
int tosend;
ssize_t n, expected = 0;
int i;
#ifdef IOV_MAX
tosend = MIN(iovcnt, IOV_MAX);
#else
tosend = iovcnt;
#endif
for (i = 0; i < tosend; i++) {
expected += iov[i].iov_len;
}
n = writev(s->socket, iov, tosend);
if (n <= expected) {
if (n > 0)
ret += n;
return ret == 0 ? n : ret;
}
ret += n;
iov += tosend;
iovcnt -= tosend;
} while(iovcnt > 0);
return ret;
}
static ssize_t stream_read_cb(RedsStream *s, void *buf, size_t size)
{
return read(s->socket, buf, size);
}
static ssize_t stream_ssl_write_cb(RedsStream *s, const void *buf, size_t size)
{
int return_code;
SPICE_GNUC_UNUSED int ssl_error;
return_code = SSL_write(s->priv->ssl, buf, size);
if (return_code < 0) {
ssl_error = SSL_get_error(s->priv->ssl, return_code);
}
return return_code;
}
static ssize_t stream_ssl_read_cb(RedsStream *s, void *buf, size_t size)
{
int return_code;
SPICE_GNUC_UNUSED int ssl_error;
return_code = SSL_read(s->priv->ssl, buf, size);
if (return_code < 0) {
ssl_error = SSL_get_error(s->priv->ssl, return_code);
}
return return_code;
}
void reds_stream_remove_watch(RedsStream* s)
{
if (s->watch) {
core->watch_remove(s->watch);
s->watch = NULL;
}
}
#if HAVE_SASL
static ssize_t reds_stream_sasl_read(RedsStream *s, uint8_t *buf, size_t nbyte);
#endif
ssize_t reds_stream_read(RedsStream *s, void *buf, size_t nbyte)
{
ssize_t ret;
#if HAVE_SASL
if (s->priv->sasl.conn && s->priv->sasl.runSSF) {
ret = reds_stream_sasl_read(s, buf, nbyte);
} else
#endif
ret = s->priv->read(s, buf, nbyte);
return ret;
}
bool reds_stream_write_all(RedsStream *stream, const void *in_buf, size_t n)
{
const uint8_t *buf = (uint8_t *)in_buf;
while (n) {
int now = reds_stream_write(stream, buf, n);
if (now <= 0) {
if (now == -1 && (errno == EINTR || errno == EAGAIN)) {
continue;
}
return FALSE;
}
n -= now;
buf += now;
}
return TRUE;
}
#if HAVE_SASL
static ssize_t reds_stream_sasl_write(RedsStream *s, const void *buf, size_t nbyte);
#endif
ssize_t reds_stream_write(RedsStream *s, const void *buf, size_t nbyte)
{
ssize_t ret;
#if HAVE_SASL
if (s->priv->sasl.conn && s->priv->sasl.runSSF) {
ret = reds_stream_sasl_write(s, buf, nbyte);
} else
#endif
ret = s->priv->write(s, buf, nbyte);
return ret;
}
int reds_stream_get_family(const RedsStream *s)
{
spice_return_val_if_fail(s != NULL, -1);
if (s->socket == -1)
return -1;
return s->priv->info->laddr_ext.ss_family;
}
int reds_stream_is_plain_unix(const RedsStream *s)
{
spice_return_val_if_fail(s != NULL, FALSE);
if (reds_stream_get_family(s) != AF_UNIX)
return FALSE;
#if HAVE_SASL
if (s->priv->sasl.conn)
return FALSE;
#endif
if (s->priv->ssl)
return FALSE;
return TRUE;
}
ssize_t reds_stream_writev(RedsStream *s, const struct iovec *iov, int iovcnt)
{
int i;
int n;
ssize_t ret = 0;
if (s->priv->writev != NULL) {
return s->priv->writev(s, iov, iovcnt);
}
for (i = 0; i < iovcnt; ++i) {
n = reds_stream_write(s, iov[i].iov_base, iov[i].iov_len);
if (n <= 0)
return ret == 0 ? n : ret;
ret += n;
}
return ret;
}
void reds_stream_free(RedsStream *s)
{
if (!s) {
return;
}
reds_stream_push_channel_event(s, SPICE_CHANNEL_EVENT_DISCONNECTED);
#if HAVE_SASL
if (s->priv->sasl.conn) {
s->priv->sasl.runSSF = s->priv->sasl.wantSSF = 0;
s->priv->sasl.len = 0;
s->priv->sasl.encodedLength = s->priv->sasl.encodedOffset = 0;
s->priv->sasl.encoded = NULL;
free(s->priv->sasl.mechlist);
free(s->priv->sasl.mechname);
s->priv->sasl.mechlist = NULL;
sasl_dispose(&s->priv->sasl.conn);
s->priv->sasl.conn = NULL;
}
#endif
if (s->priv->ssl) {
SSL_free(s->priv->ssl);
}
reds_stream_remove_watch(s);
spice_info("close socket fd %d", s->socket);
close(s->socket);
free(s);
}
void reds_stream_push_channel_event(RedsStream *s, int event)
{
main_dispatcher_channel_event(event, s->priv->info);
}
static void reds_stream_set_socket(RedsStream *stream, int socket)
{
stream->socket = socket;
/* deprecated fields. Filling them for backward compatibility */
stream->priv->info->llen = sizeof(stream->priv->info->laddr);
stream->priv->info->plen = sizeof(stream->priv->info->paddr);
getsockname(stream->socket, (struct sockaddr*)(&stream->priv->info->laddr), &stream->priv->info->llen);
getpeername(stream->socket, (struct sockaddr*)(&stream->priv->info->paddr), &stream->priv->info->plen);
stream->priv->info->flags |= SPICE_CHANNEL_EVENT_FLAG_ADDR_EXT;
stream->priv->info->llen_ext = sizeof(stream->priv->info->laddr_ext);
stream->priv->info->plen_ext = sizeof(stream->priv->info->paddr_ext);
getsockname(stream->socket, (struct sockaddr*)(&stream->priv->info->laddr_ext),
&stream->priv->info->llen_ext);
getpeername(stream->socket, (struct sockaddr*)(&stream->priv->info->paddr_ext),
&stream->priv->info->plen_ext);
}
void reds_stream_set_channel(RedsStream *stream, int connection_id,
int channel_type, int channel_id)
{
stream->priv->info->connection_id = connection_id;
stream->priv->info->type = channel_type;
stream->priv->info->id = channel_id;
}
RedsStream *reds_stream_new(int socket)
{
RedsStream *stream;
stream = spice_malloc0(sizeof(RedsStream) + sizeof(RedsStreamPrivate));
stream->priv = (RedsStreamPrivate *)(stream+1);
stream->priv->info = spice_new0(SpiceChannelEventInfo, 1);
reds_stream_set_socket(stream, socket);
stream->priv->read = stream_read_cb;
stream->priv->write = stream_write_cb;
stream->priv->writev = stream_writev_cb;
return stream;
}
bool reds_stream_is_ssl(RedsStream *stream)
{
return (stream->priv->ssl != NULL);
}
void reds_stream_set_info_flag(RedsStream *stream, unsigned int flag)
{
g_return_if_fail((flag == SPICE_CHANNEL_EVENT_FLAG_TLS)
|| (flag == SPICE_CHANNEL_EVENT_FLAG_ADDR_EXT));
stream->priv->info->flags |= flag;
}
void reds_stream_disable_writev(RedsStream *stream)
{
stream->priv->writev = NULL;
}
RedsStreamSslStatus reds_stream_ssl_accept(RedsStream *stream)
{
int ssl_error;
int return_code;
return_code = SSL_accept(stream->priv->ssl);
if (return_code == 1) {
return REDS_STREAM_SSL_STATUS_OK;
}
ssl_error = SSL_get_error(stream->priv->ssl, return_code);
if (return_code == -1 && (ssl_error == SSL_ERROR_WANT_READ ||
ssl_error == SSL_ERROR_WANT_WRITE)) {
if (ssl_error == SSL_ERROR_WANT_READ) {
return REDS_STREAM_SSL_STATUS_WAIT_FOR_READ;
} else {
return REDS_STREAM_SSL_STATUS_WAIT_FOR_WRITE;
}
}
ERR_print_errors_fp(stderr);
spice_warning("SSL_accept failed, error=%d", ssl_error);
SSL_free(stream->priv->ssl);
stream->priv->ssl = NULL;
return REDS_STREAM_SSL_STATUS_ERROR;
}
int reds_stream_enable_ssl(RedsStream *stream, SSL_CTX *ctx)
{
BIO *sbio;
// Handle SSL handshaking
if (!(sbio = BIO_new_socket(stream->socket, BIO_NOCLOSE))) {
spice_warning("could not allocate ssl bio socket");
return REDS_STREAM_SSL_STATUS_ERROR;
}
stream->priv->ssl = SSL_new(ctx);
if (!stream->priv->ssl) {
spice_warning("could not allocate ssl context");
BIO_free(sbio);
return REDS_STREAM_SSL_STATUS_ERROR;
}
SSL_set_bio(stream->priv->ssl, sbio, sbio);
stream->priv->write = stream_ssl_write_cb;
stream->priv->read = stream_ssl_read_cb;
stream->priv->writev = NULL;
return reds_stream_ssl_accept(stream);
}
void reds_stream_set_async_error_handler(RedsStream *stream,
AsyncReadError error_handler)
{
stream->priv->async_read.error = error_handler;
}
static inline void async_read_clear_handlers(AsyncRead *async)
{
if (async->stream->watch) {
reds_stream_remove_watch(async->stream);
}
async->stream = NULL;
}
static void async_read_handler(G_GNUC_UNUSED int fd,
G_GNUC_UNUSED int event,
void *data)
{
AsyncRead *async = (AsyncRead *)data;
for (;;) {
int n = async->end - async->now;
spice_assert(n > 0);
n = reds_stream_read(async->stream, async->now, n);
if (n <= 0) {
if (n < 0) {
switch (errno) {
case EAGAIN:
if (!async->stream->watch) {
async->stream->watch = core->watch_add(core, async->stream->socket,
SPICE_WATCH_EVENT_READ,
async_read_handler, async);
}
return;
case EINTR:
break;
default:
async_read_clear_handlers(async);
if (async->error) {
async->error(async->opaque, errno);
}
return;
}
} else {
async_read_clear_handlers(async);
if (async->error) {
async->error(async->opaque, 0);
}
return;
}
} else {
async->now += n;
if (async->now == async->end) {
async_read_clear_handlers(async);
async->done(async->opaque);
return;
}
}
}
}
void reds_stream_async_read(RedsStream *stream,
uint8_t *data, size_t size,
AsyncReadDone read_done_cb,
void *opaque)
{
AsyncRead *async = &stream->priv->async_read;
g_return_if_fail(!async->stream);
async->stream = stream;
async->now = data;
async->end = async->now + size;
async->done = read_done_cb;
async->opaque = opaque;
async_read_handler(0, 0, async);
}
#if HAVE_SASL
bool reds_stream_write_u8(RedsStream *s, uint8_t n)
{
return reds_stream_write_all(s, &n, sizeof(uint8_t));
}
bool reds_stream_write_u32(RedsStream *s, uint32_t n)
{
return reds_stream_write_all(s, &n, sizeof(uint32_t));
}
static ssize_t reds_stream_sasl_write(RedsStream *s, const void *buf, size_t nbyte)
{
ssize_t ret;
if (!s->priv->sasl.encoded) {
int err;
err = sasl_encode(s->priv->sasl.conn, (char *)buf, nbyte,
(const char **)&s->priv->sasl.encoded,
&s->priv->sasl.encodedLength);
if (err != SASL_OK) {
spice_warning("sasl_encode error: %d", err);
return -1;
}
if (s->priv->sasl.encodedLength == 0) {
return 0;
}
if (!s->priv->sasl.encoded) {
spice_warning("sasl_encode didn't return a buffer!");
return 0;
}
s->priv->sasl.encodedOffset = 0;
}
ret = s->priv->write(s, s->priv->sasl.encoded + s->priv->sasl.encodedOffset,
s->priv->sasl.encodedLength - s->priv->sasl.encodedOffset);
if (ret <= 0) {
return ret;
}
s->priv->sasl.encodedOffset += ret;
if (s->priv->sasl.encodedOffset == s->priv->sasl.encodedLength) {
s->priv->sasl.encoded = NULL;
s->priv->sasl.encodedOffset = s->priv->sasl.encodedLength = 0;
return nbyte;
}
/* we didn't flush the encoded buffer */
errno = EAGAIN;
return -1;
}
static ssize_t reds_stream_sasl_read(RedsStream *s, uint8_t *buf, size_t nbyte)
{
uint8_t encoded[4096];
const char *decoded;
unsigned int decodedlen;
int err;
int n;
n = spice_buffer_copy(&s->priv->sasl.inbuffer, buf, nbyte);
if (n > 0) {
spice_buffer_remove(&s->priv->sasl.inbuffer, n);
if (n == nbyte)
return n;
nbyte -= n;
buf += n;
}
n = s->priv->read(s, encoded, sizeof(encoded));
if (n <= 0) {
return n;
}
err = sasl_decode(s->priv->sasl.conn,
(char *)encoded, n,
&decoded, &decodedlen);
if (err != SASL_OK) {
spice_warning("sasl_decode error: %d", err);
return -1;
}
if (decodedlen == 0) {
errno = EAGAIN;
return -1;
}
n = MIN(nbyte, decodedlen);
memcpy(buf, decoded, n);
spice_buffer_append(&s->priv->sasl.inbuffer, decoded + n, decodedlen - n);
return n;
}
static char *addr_to_string(const char *format,
struct sockaddr_storage *sa,
socklen_t salen)
{
char *addr;
char host[NI_MAXHOST];
char serv[NI_MAXSERV];
int err;
size_t addrlen;
if ((err = getnameinfo((struct sockaddr *)sa, salen,
host, sizeof(host),
serv, sizeof(serv),
NI_NUMERICHOST | NI_NUMERICSERV)) != 0) {
spice_warning("Cannot resolve address %d: %s",
err, gai_strerror(err));
return NULL;
}
/* Enough for the existing format + the 2 vars we're
* substituting in. */
addrlen = strlen(format) + strlen(host) + strlen(serv);
addr = spice_malloc(addrlen + 1);
snprintf(addr, addrlen, format, host, serv);
addr[addrlen] = '\0';
return addr;
}
static char *reds_stream_get_local_address(RedsStream *stream)
{
return addr_to_string("%s;%s", &stream->priv->info->laddr_ext,
stream->priv->info->llen_ext);
}
static char *reds_stream_get_remote_address(RedsStream *stream)
{
return addr_to_string("%s;%s", &stream->priv->info->paddr_ext,
stream->priv->info->plen_ext);
}
static int auth_sasl_check_ssf(RedsSASL *sasl, int *runSSF)
{
const void *val;
int err, ssf;
*runSSF = 0;
if (!sasl->wantSSF) {
return 1;
}
err = sasl_getprop(sasl->conn, SASL_SSF, &val);
if (err != SASL_OK) {
return 0;
}
ssf = *(const int *)val;
spice_info("negotiated an SSF of %d", ssf);
if (ssf < 56) {
return 0; /* 56 is good for Kerberos */
}
*runSSF = 1;
/* We have a SSF that's good enough */
return 1;
}
/*
* Step Msg
*
* Input from client:
*
* u32 clientin-length
* u8-array clientin-string
*
* Output to client:
*
* u32 serverout-length
* u8-array serverout-strin
* u8 continue
*/
#define SASL_DATA_MAX_LEN (1024 * 1024)
RedsSaslError reds_sasl_handle_auth_step(RedsStream *stream, AsyncReadDone read_cb, void *opaque)
{
const char *serverout;
unsigned int serveroutlen;
int err;
char *clientdata = NULL;
RedsSASL *sasl = &stream->priv->sasl;
uint32_t datalen = sasl->len;
/* NB, distinction of NULL vs "" is *critical* in SASL */
if (datalen) {
clientdata = sasl->data;
clientdata[datalen - 1] = '\0'; /* Wire includes '\0', but make sure */
datalen--; /* Don't count NULL byte when passing to _start() */
}
spice_info("Step using SASL Data %p (%d bytes)",
clientdata, datalen);
err = sasl_server_step(sasl->conn,
clientdata,
datalen,
&serverout,
&serveroutlen);
if (err != SASL_OK &&
err != SASL_CONTINUE) {
spice_warning("sasl step failed %d (%s)",
err, sasl_errdetail(sasl->conn));
return REDS_SASL_ERROR_GENERIC;
}
if (serveroutlen > SASL_DATA_MAX_LEN) {
spice_warning("sasl step reply data too long %d",
serveroutlen);
return REDS_SASL_ERROR_INVALID_DATA;
}
spice_info("SASL return data %d bytes, %p", serveroutlen, serverout);
if (serveroutlen) {
serveroutlen += 1;
reds_stream_write_all(stream, &serveroutlen, sizeof(uint32_t));
reds_stream_write_all(stream, serverout, serveroutlen);
} else {
reds_stream_write_all(stream, &serveroutlen, sizeof(uint32_t));
}
/* Whether auth is complete */
reds_stream_write_u8(stream, err == SASL_CONTINUE ? 0 : 1);
if (err == SASL_CONTINUE) {
spice_info("%s", "Authentication must continue (step)");
/* Wait for step length */
reds_stream_async_read(stream, (uint8_t *)&sasl->len, sizeof(uint32_t),
read_cb, opaque);
return REDS_SASL_ERROR_CONTINUE;
} else {
int ssf;
if (auth_sasl_check_ssf(sasl, &ssf) == 0) {
spice_warning("Authentication rejected for weak SSF");
goto authreject;
}
spice_info("Authentication successful");
reds_stream_write_u32(stream, SPICE_LINK_ERR_OK); /* Accept auth */
/*
* Delay writing in SSF encoded until now
*/
sasl->runSSF = ssf;
reds_stream_disable_writev(stream); /* make sure writev isn't called directly anymore */
return REDS_SASL_ERROR_OK;
}
authreject:
reds_stream_write_u32(stream, 1); /* Reject auth */
reds_stream_write_u32(stream, sizeof("Authentication failed"));
reds_stream_write_all(stream, "Authentication failed", sizeof("Authentication failed"));
return REDS_SASL_ERROR_AUTH_FAILED;
}
RedsSaslError reds_sasl_handle_auth_steplen(RedsStream *stream, AsyncReadDone read_cb, void *opaque)
{
RedsSASL *sasl = &stream->priv->sasl;
spice_info("Got steplen %d", sasl->len);
if (sasl->len > SASL_DATA_MAX_LEN) {
spice_warning("Too much SASL data %d", sasl->len);
return REDS_SASL_ERROR_INVALID_DATA;
}
if (sasl->len == 0) {
read_cb(opaque);
/* FIXME: can't report potential errors correctly here,
* but read_cb() will have done the needed RedLinkInfo cleanups
* if an error occurs, so the caller should not need to do more
* treatment */
return REDS_SASL_ERROR_OK;
} else {
sasl->data = spice_realloc(sasl->data, sasl->len);
reds_stream_async_read(stream, (uint8_t *)sasl->data, sasl->len,
read_cb, opaque);
return REDS_SASL_ERROR_OK;
}
}
/*
* Start Msg
*
* Input from client:
*
* u32 clientin-length
* u8-array clientin-string
*
* Output to client:
*
* u32 serverout-length
* u8-array serverout-strin
* u8 continue
*/
RedsSaslError reds_sasl_handle_auth_start(RedsStream *stream, AsyncReadDone read_cb, void *opaque)
{
const char *serverout;
unsigned int serveroutlen;
int err;
char *clientdata = NULL;
RedsSASL *sasl = &stream->priv->sasl;
uint32_t datalen = sasl->len;
/* NB, distinction of NULL vs "" is *critical* in SASL */
if (datalen) {
clientdata = sasl->data;
clientdata[datalen - 1] = '\0'; /* Should be on wire, but make sure */
datalen--; /* Don't count NULL byte when passing to _start() */
}
spice_info("Start SASL auth with mechanism %s. Data %p (%d bytes)",
sasl->mechlist, clientdata, datalen);
err = sasl_server_start(sasl->conn,
sasl->mechlist,
clientdata,
datalen,
&serverout,
&serveroutlen);
if (err != SASL_OK &&
err != SASL_CONTINUE) {
spice_warning("sasl start failed %d (%s)",
err, sasl_errdetail(sasl->conn));
return REDS_SASL_ERROR_INVALID_DATA;
}
if (serveroutlen > SASL_DATA_MAX_LEN) {
spice_warning("sasl start reply data too long %d",
serveroutlen);
return REDS_SASL_ERROR_INVALID_DATA;
}
spice_info("SASL return data %d bytes, %p", serveroutlen, serverout);
if (serveroutlen) {
serveroutlen += 1;
reds_stream_write_all(stream, &serveroutlen, sizeof(uint32_t));
reds_stream_write_all(stream, serverout, serveroutlen);
} else {
reds_stream_write_all(stream, &serveroutlen, sizeof(uint32_t));
}
/* Whether auth is complete */
reds_stream_write_u8(stream, err == SASL_CONTINUE ? 0 : 1);
if (err == SASL_CONTINUE) {
spice_info("%s", "Authentication must continue (start)");
/* Wait for step length */
reds_stream_async_read(stream, (uint8_t *)&sasl->len, sizeof(uint32_t),
read_cb, opaque);
return REDS_SASL_ERROR_CONTINUE;
} else {
int ssf;
if (auth_sasl_check_ssf(sasl, &ssf) == 0) {
spice_warning("Authentication rejected for weak SSF");
goto authreject;
}
spice_info("Authentication successful");
reds_stream_write_u32(stream, SPICE_LINK_ERR_OK); /* Accept auth */
/*
* Delay writing in SSF encoded until now
*/
sasl->runSSF = ssf;
reds_stream_disable_writev(stream); /* make sure writev isn't called directly anymore */
return REDS_SASL_ERROR_OK;
}
authreject:
reds_stream_write_u32(stream, 1); /* Reject auth */
reds_stream_write_u32(stream, sizeof("Authentication failed"));
reds_stream_write_all(stream, "Authentication failed", sizeof("Authentication failed"));
return REDS_SASL_ERROR_AUTH_FAILED;
}
RedsSaslError reds_sasl_handle_auth_startlen(RedsStream *stream, AsyncReadDone read_cb, void *opaque)
{
RedsSASL *sasl = &stream->priv->sasl;
spice_info("Got client start len %d", sasl->len);
if (sasl->len > SASL_DATA_MAX_LEN) {
spice_warning("Too much SASL data %d", sasl->len);
return REDS_SASL_ERROR_INVALID_DATA;
}
if (sasl->len == 0) {
return REDS_SASL_ERROR_RETRY;
}
sasl->data = spice_realloc(sasl->data, sasl->len);
reds_stream_async_read(stream, (uint8_t *)sasl->data, sasl->len,
read_cb, opaque);
return REDS_SASL_ERROR_OK;
}
bool reds_sasl_handle_auth_mechname(RedsStream *stream, AsyncReadDone read_cb, void *opaque)
{
RedsSASL *sasl = &stream->priv->sasl;
sasl->mechname[sasl->len] = '\0';
spice_info("Got client mechname '%s' check against '%s'",
sasl->mechname, sasl->mechlist);
if (strncmp(sasl->mechlist, sasl->mechname, sasl->len) == 0) {
if (sasl->mechlist[sasl->len] != '\0' &&
sasl->mechlist[sasl->len] != ',') {
spice_info("One %d", sasl->mechlist[sasl->len]);
return FALSE;
}
} else {
char *offset = strstr(sasl->mechlist, sasl->mechname);
spice_info("Two %p", offset);
if (!offset) {
return FALSE;
}
spice_info("Two '%s'", offset);
if (offset[-1] != ',' ||
(offset[sasl->len] != '\0'&&
offset[sasl->len] != ',')) {
return FALSE;
}
}
free(sasl->mechlist);
sasl->mechlist = spice_strdup(sasl->mechname);
spice_info("Validated mechname '%s'", sasl->mechname);
reds_stream_async_read(stream, (uint8_t *)&sasl->len, sizeof(uint32_t),
read_cb, opaque);
return TRUE;
}
bool reds_sasl_handle_auth_mechlen(RedsStream *stream, AsyncReadDone read_cb, void *opaque)
{
RedsSASL *sasl = &stream->priv->sasl;
if (sasl->len < 1 || sasl->len > 100) {
spice_warning("Got bad client mechname len %d", sasl->len);
return FALSE;
}
sasl->mechname = spice_malloc(sasl->len + 1);
spice_info("Wait for client mechname");
reds_stream_async_read(stream, (uint8_t *)sasl->mechname, sasl->len,
read_cb, opaque);
return TRUE;
}
bool reds_sasl_start_auth(RedsStream *stream, AsyncReadDone read_cb, void *opaque)
{
const char *mechlist = NULL;
sasl_security_properties_t secprops;
int err;
char *localAddr, *remoteAddr;
int mechlistlen;
RedsSASL *sasl = &stream->priv->sasl;
if (!(localAddr = reds_stream_get_local_address(stream))) {
goto error;
}
if (!(remoteAddr = reds_stream_get_remote_address(stream))) {
free(localAddr);
goto error;
}
err = sasl_server_new("spice",
NULL, /* FQDN - just delegates to gethostname */
NULL, /* User realm */
localAddr,
remoteAddr,
NULL, /* Callbacks, not needed */
SASL_SUCCESS_DATA,
&sasl->conn);
free(localAddr);
free(remoteAddr);
localAddr = remoteAddr = NULL;
if (err != SASL_OK) {
spice_warning("sasl context setup failed %d (%s)",
err, sasl_errstring(err, NULL, NULL));
sasl->conn = NULL;
goto error;
}
/* Inform SASL that we've got an external SSF layer from TLS */
if (stream->priv->ssl) {
sasl_ssf_t ssf;
ssf = SSL_get_cipher_bits(stream->priv->ssl, NULL);
err = sasl_setprop(sasl->conn, SASL_SSF_EXTERNAL, &ssf);
if (err != SASL_OK) {
spice_warning("cannot set SASL external SSF %d (%s)",
err, sasl_errstring(err, NULL, NULL));
goto error_dispose;
}
} else {
sasl->wantSSF = 1;
}
memset(&secprops, 0, sizeof secprops);
/* Inform SASL that we've got an external SSF layer from TLS */
if (stream->priv->ssl) {
/* If we've got TLS (or UNIX domain sock), we don't care about SSF */
secprops.min_ssf = 0;
secprops.max_ssf = 0;
secprops.maxbufsize = 8192;
secprops.security_flags = 0;
} else {
/* Plain TCP, better get an SSF layer */
secprops.min_ssf = 56; /* Good enough to require kerberos */
secprops.max_ssf = 100000; /* Arbitrary big number */
secprops.maxbufsize = 8192;
/* Forbid any anonymous or trivially crackable auth */
secprops.security_flags =
SASL_SEC_NOANONYMOUS | SASL_SEC_NOPLAINTEXT;
}
err = sasl_setprop(sasl->conn, SASL_SEC_PROPS, &secprops);
if (err != SASL_OK) {
spice_warning("cannot set SASL security props %d (%s)",
err, sasl_errstring(err, NULL, NULL));
goto error_dispose;
}
err = sasl_listmech(sasl->conn,
NULL, /* Don't need to set user */
"", /* Prefix */
",", /* Separator */
"", /* Suffix */
&mechlist,
NULL,
NULL);
if (err != SASL_OK || mechlist == NULL) {
spice_warning("cannot list SASL mechanisms %d (%s)",
err, sasl_errdetail(sasl->conn));
goto error_dispose;
}
spice_info("Available mechanisms for client: '%s'", mechlist);
sasl->mechlist = spice_strdup(mechlist);
mechlistlen = strlen(mechlist);
if (!reds_stream_write_all(stream, &mechlistlen, sizeof(uint32_t))
|| !reds_stream_write_all(stream, sasl->mechlist, mechlistlen)) {
spice_warning("SASL mechanisms write error");
goto error;
}
spice_info("Wait for client mechname length");
reds_stream_async_read(stream, (uint8_t *)&sasl->len, sizeof(uint32_t),
read_cb, opaque);
return TRUE;
error_dispose:
sasl_dispose(&sasl->conn);
sasl->conn = NULL;
error:
return FALSE;
}
#endif
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