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libtdevnc
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Add the OpenSSL libvncclient TLS version to the build system.

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pull/1/head
Christian Beier 13 years ago
parent 98f4037785
commit 5e9da5a2f8
4 changed files with 657 additions and 1 deletions
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16
libvncclient/Makefile.am
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@ -1,6 +1,20 @@
INCLUDES = -I$(top_srcdir) -I$(top_srcdir)/common
libvncclient_la_SOURCES=cursor.c listen.c rfbproto.c sockets.c vncviewer.c ../common/minilzo.c tls.c
if HAVE_GNUTLS
TLSSRCS = tls_gnutls.c
TLSLIBS = @GNUTLS_LIBS@
else
if HAVE_LIBSSL
TLSSRCS = tls_openssl.c
TLSLIBS = @SSL_LIBS@ @CRYPT_LIBS@
else
TLSSRCS = tls_none.c
endif
endif
libvncclient_la_SOURCES=cursor.c listen.c rfbproto.c sockets.c vncviewer.c ../common/minilzo.c $(TLSSRCS)
libvncclient_la_LIBADD=$(TLSLIBS)
noinst_HEADERS=../common/lzodefs.h ../common/lzoconf.h ../common/minilzo.h tls.h

0
libvncclient/tls.c → libvncclient/tls_gnutls.c
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56
libvncclient/tls_none.c
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@ -0,0 +1,56 @@
/*
* Copyright (C) 2012 Christian Beier.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#include "tls.h"
rfbBool HandleAnonTLSAuth(rfbClient* client)
{
rfbClientLog("TLS is not supported.\n");
return FALSE;
}
rfbBool HandleVeNCryptAuth(rfbClient* client)
{
rfbClientLog("TLS is not supported.\n");
return FALSE;
}
int ReadFromTLS(rfbClient* client, char *out, unsigned int n)
{
rfbClientLog("TLS is not supported.\n");
errno = EINTR;
return -1;
}
int WriteToTLS(rfbClient* client, char *buf, unsigned int n)
{
rfbClientLog("TLS is not supported.\n");
errno = EINTR;
return -1;
}
void FreeTLS(rfbClient* client)
{
}

586
libvncclient/tls_openssl.c
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@ -0,0 +1,586 @@
/*
* Copyright (C) 2012 Philip Van Hoof <philip@codeminded.be>
* Copyright (C) 2009 Vic Lee.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#include <rfb/rfbclient.h>
#include <errno.h>
#include <openssl/err.h>
#include <openssl/ssl.h>
#include <openssl/x509.h>
#include <openssl/rand.h>
#include <openssl/x509.h>
#include <pthread.h>
#include "tls.h"
static rfbBool rfbTLSInitialized = FALSE;
static pthread_mutex_t *mutex_buf = NULL;
struct CRYPTO_dynlock_value {
pthread_mutex_t mutex;
};
static void locking_function(int mode, int n, const char *file, int line)
{
if (mode & CRYPTO_LOCK)
pthread_mutex_lock(&mutex_buf[n]);
else
pthread_mutex_unlock(&mutex_buf[n]);
}
static unsigned long id_function(void)
{
return ((unsigned long) pthread_self());
}
static struct CRYPTO_dynlock_value *dyn_create_function(const char *file, int line)
{
struct CRYPTO_dynlock_value *value;
value = (struct CRYPTO_dynlock_value *)
malloc(sizeof(struct CRYPTO_dynlock_value));
if (!value)
goto err;
pthread_mutex_init(&value->mutex, NULL);
return value;
err:
return (NULL);
}
static void dyn_lock_function (int mode, struct CRYPTO_dynlock_value *l, const char *file, int line)
{
if (mode & CRYPTO_LOCK)
pthread_mutex_lock(&l->mutex);
else
pthread_mutex_unlock(&l->mutex);
}
static void
dyn_destroy_function(struct CRYPTO_dynlock_value *l, const char *file, int line)
{
pthread_mutex_destroy(&l->mutex);
free(l);
}
static int
ssl_errno (SSL *ssl, int ret)
{
switch (SSL_get_error (ssl, ret)) {
case SSL_ERROR_NONE:
return 0;
case SSL_ERROR_ZERO_RETURN:
/* this one does not map well at all */
//d(printf ("ssl_errno: SSL_ERROR_ZERO_RETURN\n"));
return EINVAL;
case SSL_ERROR_WANT_READ: /* non-fatal; retry */
case SSL_ERROR_WANT_WRITE: /* non-fatal; retry */
//d(printf ("ssl_errno: SSL_ERROR_WANT_[READ,WRITE]\n"));
return EAGAIN;
case SSL_ERROR_SYSCALL:
//d(printf ("ssl_errno: SSL_ERROR_SYSCALL\n"));
return EINTR;
case SSL_ERROR_SSL:
//d(printf ("ssl_errno: SSL_ERROR_SSL <-- very useful error...riiiiight\n"));
return EINTR;
default:
//d(printf ("ssl_errno: default error\n"));
return EINTR;
}
}
static rfbBool
InitializeTLS(void)
{
int i;
if (rfbTLSInitialized) return TRUE;
mutex_buf = malloc(CRYPTO_num_locks() * sizeof(pthread_mutex_t));
if (mutex_buf == NULL) {
rfbClientLog("Failed to initialized OpenSSL: memory.\n");
return (-1);
}
for (i = 0; i < CRYPTO_num_locks(); i++)
pthread_mutex_init(&mutex_buf[i], NULL);
CRYPTO_set_locking_callback(locking_function);
CRYPTO_set_id_callback(id_function);
CRYPTO_set_dynlock_create_callback(dyn_create_function);
CRYPTO_set_dynlock_lock_callback(dyn_lock_function);
CRYPTO_set_dynlock_destroy_callback(dyn_destroy_function);
SSL_load_error_strings();
SSLeay_add_ssl_algorithms();
RAND_load_file("/dev/urandom", 1024);
rfbClientLog("OpenSSL initialized.\n");
rfbTLSInitialized = TRUE;
return TRUE;
}
static int
ssl_verify (int ok, X509_STORE_CTX *ctx)
{
unsigned char md5sum[16], fingerprint[40], *f;
rfbClient *client;
char *prompt, *cert_str;
int err, i;
unsigned int md5len;
//char buf[257];
X509 *cert;
SSL *ssl;
if (ok)
return TRUE;
ssl = X509_STORE_CTX_get_ex_data (ctx, SSL_get_ex_data_X509_STORE_CTX_idx ());
client = SSL_CTX_get_app_data (ssl->ctx);
cert = X509_STORE_CTX_get_current_cert (ctx);
err = X509_STORE_CTX_get_error (ctx);
/* calculate the MD5 hash of the raw certificate */
md5len = sizeof (md5sum);
X509_digest (cert, EVP_md5 (), md5sum, &md5len);
for (i = 0, f = fingerprint; i < 16; i++, f += 3)
sprintf ((char *) f, "%.2x%c", md5sum[i], i != 15 ? ':' : '\0');
#define GET_STRING(name) X509_NAME_oneline (name, buf, 256)
/* TODO: Don't just ignore certificate checks
fingerprint = key to check in db
GET_STRING (X509_get_issuer_name (cert));
GET_STRING (X509_get_subject_name (cert));
cert->valid (bool: GOOD or BAD) */
ok = TRUE;
return ok;
}
static int sock_read_ready(SSL *ssl, uint32_t ms)
{
int r = 0;
fd_set fds;
struct timeval tv;
FD_ZERO(&fds);
FD_SET(SSL_get_fd(ssl), &fds);
tv.tv_sec = ms / 1000;
tv.tv_usec = (ms % 1000) * ms;
r = select (SSL_get_fd(ssl) + 1, &fds, NULL, NULL, &tv);
return r;
}
static int wait_for_data(SSL *ssl, int ret, int timeout)
{
struct timeval tv;
fd_set fds;
int err;
int retval = 1;
err = SSL_get_error(ssl, ret);
switch(err)
{
case SSL_ERROR_WANT_READ:
case SSL_ERROR_WANT_WRITE:
ret = sock_read_ready(ssl, timeout*1000);
if (ret == -1) {
retval = 2;
}
break;
default:
retval = 3;
break;
}
ERR_clear_error();
return retval;
}
static SSL *
open_ssl_connection (rfbClient *client, int sockfd, rfbBool anonTLS)
{
SSL_CTX *ssl_ctx = NULL;
SSL *ssl = NULL;
int n, finished = 0;
BIO *sbio;
ssl_ctx = SSL_CTX_new (SSLv23_client_method ());
SSL_CTX_set_default_verify_paths (ssl_ctx);
SSL_CTX_set_verify (ssl_ctx, SSL_VERIFY_NONE, &ssl_verify);
ssl = SSL_new (ssl_ctx);
/* TODO: finetune this list, take into account anonTLS bool */
SSL_set_cipher_list(ssl, "ALL");
SSL_set_fd (ssl, sockfd);
SSL_CTX_set_app_data (ssl_ctx, client);
do
{
n = SSL_connect(ssl);
if (n != 1)
{
if (wait_for_data(ssl, n, 1) != 1)
{
finished = 1;
if (ssl->ctx)
SSL_CTX_free (ssl->ctx);
SSL_free(ssl);
SSL_shutdown (ssl);
return NULL;
}
}
} while( n != 1 && finished != 1 );
return ssl;
}
static rfbBool
InitializeTLSSession(rfbClient* client, rfbBool anonTLS)
{
int ret;
if (client->tlsSession) return TRUE;
client->tlsSession = open_ssl_connection (client, client->sock, anonTLS);
if (!client->tlsSession)
return FALSE;
rfbClientLog("TLS session initialized.\n");
return TRUE;
}
static rfbBool
SetTLSAnonCredential(rfbClient* client)
{
rfbClientLog("TLS anonymous credential created.\n");
return TRUE;
}
static rfbBool
HandshakeTLS(rfbClient* client)
{
int timeout = 15;
int ret;
return TRUE;
while (timeout > 0 && (ret = SSL_do_handshake(client->tlsSession)) < 0)
{
if (ret != -1)
{
rfbClientLog("TLS handshake blocking.\n");
sleep(1);
timeout--;
continue;
}
rfbClientLog("TLS handshake failed: -.\n");
FreeTLS(client);
return FALSE;
}
if (timeout <= 0)
{
rfbClientLog("TLS handshake timeout.\n");
FreeTLS(client);
return FALSE;
}
rfbClientLog("TLS handshake done.\n");
return TRUE;
}
/* VeNCrypt sub auth. 1 byte auth count, followed by count * 4 byte integers */
static rfbBool
ReadVeNCryptSecurityType(rfbClient* client, uint32_t *result)
{
uint8_t count=0;
uint8_t loop=0;
uint8_t flag=0;
uint32_t tAuth[256], t;
char buf1[500],buf2[10];
uint32_t authScheme;
if (!ReadFromRFBServer(client, (char *)&count, 1)) return FALSE;
if (count==0)
{
rfbClientLog("List of security types is ZERO. Giving up.\n");
return FALSE;
}
if (count>sizeof(tAuth))
{
rfbClientLog("%d security types are too many; maximum is %d\n", count, sizeof(tAuth));
return FALSE;
}
rfbClientLog("We have %d security types to read\n", count);
authScheme=0;
/* now, we have a list of available security types to read ( uint8_t[] ) */
for (loop=0;loop<count;loop++)
{
if (!ReadFromRFBServer(client, (char *)&tAuth[loop], 4)) return FALSE;
t=rfbClientSwap32IfLE(tAuth[loop]);
rfbClientLog("%d) Received security type %d\n", loop, t);
if (flag) continue;
if (t==rfbVeNCryptTLSNone ||
t==rfbVeNCryptTLSVNC ||
t==rfbVeNCryptTLSPlain ||
t==rfbVeNCryptX509None ||
t==rfbVeNCryptX509VNC ||
t==rfbVeNCryptX509Plain)
{
flag++;
authScheme=t;
rfbClientLog("Selecting security type %d (%d/%d in the list)\n", authScheme, loop, count);
/* send back 4 bytes (in original byte order!) indicating which security type to use */
if (!WriteToRFBServer(client, (char *)&tAuth[loop], 4)) return FALSE;
}
tAuth[loop]=t;
}
if (authScheme==0)
{
memset(buf1, 0, sizeof(buf1));
for (loop=0;loop<count;loop++)
{
if (strlen(buf1)>=sizeof(buf1)-1) break;
snprintf(buf2, sizeof(buf2), (loop>0 ? ", %d" : "%d"), (int)tAuth[loop]);
strncat(buf1, buf2, sizeof(buf1)-strlen(buf1)-1);
}
rfbClientLog("Unknown VeNCrypt authentication scheme from VNC server: %s\n",
buf1);
return FALSE;
}
*result = authScheme;
return TRUE;
}
rfbBool
HandleAnonTLSAuth(rfbClient* client)
{
if (!InitializeTLS() || !InitializeTLSSession(client, TRUE)) return FALSE;
if (!SetTLSAnonCredential(client)) return FALSE;
if (!HandshakeTLS(client)) return FALSE;
return TRUE;
}
rfbBool
HandleVeNCryptAuth(rfbClient* client)
{
uint8_t major, minor, status;
uint32_t authScheme;
rfbBool anonTLS;
// gnutls_certificate_credentials_t x509_cred = NULL;
int ret;
if (!InitializeTLS()) return FALSE;
/* Read VeNCrypt version */
if (!ReadFromRFBServer(client, (char *)&major, 1) ||
!ReadFromRFBServer(client, (char *)&minor, 1))
{
return FALSE;
}
rfbClientLog("Got VeNCrypt version %d.%d from server.\n", (int)major, (int)minor);
if (major != 0 && minor != 2)
{
rfbClientLog("Unsupported VeNCrypt version.\n");
return FALSE;
}
if (!WriteToRFBServer(client, (char *)&major, 1) ||
!WriteToRFBServer(client, (char *)&minor, 1) ||
!ReadFromRFBServer(client, (char *)&status, 1))
{
return FALSE;
}
if (status != 0)
{
rfbClientLog("Server refused VeNCrypt version %d.%d.\n", (int)major, (int)minor);
return FALSE;
}
if (!ReadVeNCryptSecurityType(client, &authScheme)) return FALSE;
if (!ReadFromRFBServer(client, (char *)&status, 1) || status != 1)
{
rfbClientLog("Server refused VeNCrypt authentication %d (%d).\n", authScheme, (int)status);
return FALSE;
}
client->subAuthScheme = authScheme;
/* Some VeNCrypt security types are anonymous TLS, others are X509 */
switch (authScheme)
{
case rfbVeNCryptTLSNone:
case rfbVeNCryptTLSVNC:
case rfbVeNCryptTLSPlain:
anonTLS = TRUE;
break;
default:
anonTLS = FALSE;
break;
}
/* Get X509 Credentials if it's not anonymous */
if (!anonTLS)
{
rfbCredential *cred;
if (!client->GetCredential)
{
rfbClientLog("GetCredential callback is not set.\n");
return FALSE;
}
cred = client->GetCredential(client, rfbCredentialTypeX509);
if (!cred)
{
rfbClientLog("Reading credential failed\n");
return FALSE;
}
/* TODO: don't just ignore this
x509_cred = CreateX509CertCredential(cred);
FreeX509Credential(cred);
if (!x509_cred) return FALSE; */
}
/* Start up the TLS session */
if (!InitializeTLSSession(client, anonTLS)) return FALSE;
if (anonTLS)
{
if (!SetTLSAnonCredential(client)) return FALSE;
}
else
{
/* TODO: don't just ignore this
if ((ret = gnutls_credentials_set(client->tlsSession, GNUTLS_CRD_CERTIFICATE, x509_cred)) < 0)
{
rfbClientLog("Cannot set x509 credential: %s.\n", gnutls_strerror(ret));
FreeTLS(client); */
return FALSE;
// }
}
if (!HandshakeTLS(client)) return FALSE;
/* TODO: validate certificate */
/* We are done here. The caller should continue with client->subAuthScheme
* to do actual sub authentication.
*/
return TRUE;
}
int
ReadFromTLS(rfbClient* client, char *out, unsigned int n)
{
ssize_t ret;
ret = SSL_read (client->tlsSession, out, n);
if (ret >= 0)
return ret;
else {
errno = ssl_errno (client->tlsSession, ret);
if (errno != EAGAIN) {
rfbClientLog("Error reading from TLS: -.\n");
}
}
return -1;
}
int
WriteToTLS(rfbClient* client, char *buf, unsigned int n)
{
unsigned int offset = 0;
ssize_t ret;
while (offset < n)
{
ret = SSL_write (client->tlsSession, buf + offset, (size_t)(n-offset));
if (ret < 0)
errno = ssl_errno (client->tlsSession, ret);
if (ret == 0) continue;
if (ret < 0)
{
if (errno == EAGAIN || errno == EWOULDBLOCK) continue;
rfbClientLog("Error writing to TLS: -\n");
return -1;
}
offset += (unsigned int)ret;
}
return offset;
}
void FreeTLS(rfbClient* client)
{
int i;
if (mutex_buf == NULL)
return (0);
CRYPTO_set_dynlock_create_callback(NULL);
CRYPTO_set_dynlock_lock_callback(NULL);
CRYPTO_set_dynlock_destroy_callback(NULL);
CRYPTO_set_locking_callback(NULL);
CRYPTO_set_id_callback(NULL);
for (i = 0; i < CRYPTO_num_locks(); i++)
pthread_mutex_destroy(&mutex_buf[i]);
free(mutex_buf);
mutex_buf = NULL;
}
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