Add ARD (Apple Remote Desktop) security type support

Signed-off-by: Vic Lee <llyzs@163.com>
Signed-off-by: Christian Beier <dontmind@freeshell.org>

4 files changed, 342 insertions, 0 deletions

diff --git a/acinclude.m4 b/acinclude.m4
index c69a38d..fc947ac 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -6999,3 +6999,112 @@ done
 SED=$lt_cv_path_SED
 AC_MSG_RESULT([$SED])
 ])
+
+dnl Autoconf macros for libgcrypt
+dnl       Copyright (C) 2002, 2004 Free Software Foundation, Inc.
+dnl
+dnl This file is free software; as a special exception the author gives
+dnl unlimited permission to copy and/or distribute it, with or without
+dnl modifications, as long as this notice is preserved.
+dnl
+dnl This file is distributed in the hope that it will be useful, but
+dnl WITHOUT ANY WARRANTY, to the extent permitted by law; without even the
+dnl implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+
+dnl AM_PATH_LIBGCRYPT([MINIMUM-VERSION,
+dnl                   [ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND ]]])
+dnl Test for libgcrypt and define LIBGCRYPT_CFLAGS and LIBGCRYPT_LIBS.
+dnl MINIMUN-VERSION is a string with the version number optionalliy prefixed
+dnl with the API version to also check the API compatibility. Example:
+dnl a MINIMUN-VERSION of 1:1.2.5 won't pass the test unless the installed 
+dnl version of libgcrypt is at least 1.2.5 *and* the API number is 1.  Using
+dnl this features allows to prevent build against newer versions of libgcrypt
+dnl with a changed API.
+dnl
+AC_DEFUN([AM_PATH_LIBGCRYPT],
+[ AC_ARG_WITH(libgcrypt-prefix,
+            AC_HELP_STRING([--with-libgcrypt-prefix=PFX],
+                           [prefix where LIBGCRYPT is installed (optional)]),
+     libgcrypt_config_prefix="$withval", libgcrypt_config_prefix="")
+  if test x$libgcrypt_config_prefix != x ; then
+     if test x${LIBGCRYPT_CONFIG+set} != xset ; then
+        LIBGCRYPT_CONFIG=$libgcrypt_config_prefix/bin/libgcrypt-config
+     fi
+  fi
+
+  AC_PATH_PROG(LIBGCRYPT_CONFIG, libgcrypt-config, no)
+  tmp=ifelse([$1], ,1:1.2.0,$1)
+  if echo "$tmp" | grep ':' >/dev/null 2>/dev/null ; then
+     req_libgcrypt_api=`echo "$tmp"     | sed 's/\(.*\):\(.*\)/\1/'`
+     min_libgcrypt_version=`echo "$tmp" | sed 's/\(.*\):\(.*\)/\2/'`
+  else
+     req_libgcrypt_api=0
+     min_libgcrypt_version="$tmp"
+  fi
+
+  AC_MSG_CHECKING(for LIBGCRYPT - version >= $min_libgcrypt_version)
+  ok=no
+  if test "$LIBGCRYPT_CONFIG" != "no" ; then
+    req_major=`echo $min_libgcrypt_version | \
+               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\)/\1/'`
+    req_minor=`echo $min_libgcrypt_version | \
+               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\)/\2/'`
+    req_micro=`echo $min_libgcrypt_version | \
+               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\)/\3/'`
+    libgcrypt_config_version=`$LIBGCRYPT_CONFIG --version`
+    major=`echo $libgcrypt_config_version | \
+               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\).*/\1/'`
+    minor=`echo $libgcrypt_config_version | \
+               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\).*/\2/'`
+    micro=`echo $libgcrypt_config_version | \
+               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\).*/\3/'`
+    if test "$major" -gt "$req_major"; then
+        ok=yes
+    else 
+        if test "$major" -eq "$req_major"; then
+            if test "$minor" -gt "$req_minor"; then
+               ok=yes
+            else
+               if test "$minor" -eq "$req_minor"; then
+                   if test "$micro" -ge "$req_micro"; then
+                     ok=yes
+                   fi
+               fi
+            fi
+        fi
+    fi
+  fi
+  if test $ok = yes; then
+    AC_MSG_RESULT([yes ($libgcrypt_config_version)])
+  else
+    AC_MSG_RESULT(no)
+  fi
+  if test $ok = yes; then
+     # If we have a recent libgcrypt, we should also check that the
+     # API is compatible
+     if test "$req_libgcrypt_api" -gt 0 ; then
+        tmp=`$LIBGCRYPT_CONFIG --api-version 2>/dev/null || echo 0`
+        if test "$tmp" -gt 0 ; then
+           AC_MSG_CHECKING([LIBGCRYPT API version])
+           if test "$req_libgcrypt_api" -eq "$tmp" ; then
+             AC_MSG_RESULT([okay])
+           else
+             ok=no
+             AC_MSG_RESULT([does not match. want=$req_libgcrypt_api got=$tmp])
+           fi
+        fi
+     fi
+  fi
+  if test $ok = yes; then
+    LIBGCRYPT_CFLAGS=`$LIBGCRYPT_CONFIG --cflags`
+    LIBGCRYPT_LIBS=`$LIBGCRYPT_CONFIG --libs`
+    ifelse([$2], , :, [$2])
+  else
+    LIBGCRYPT_CFLAGS=""
+    LIBGCRYPT_LIBS=""
+    ifelse([$3], , :, [$3])
+  fi
+  AC_SUBST(LIBGCRYPT_CFLAGS)
+  AC_SUBST(LIBGCRYPT_LIBS)
+])
diff --git a/configure.ac b/configure.ac
index 4ad489b..bf760dd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -689,6 +689,22 @@ if test ! -z "$MINGW"; then
 fi
 AC_SUBST(WSOCKLIB)
 
+# Check for libgcrypt
+AH_TEMPLATE(WITH_CLIENT_GCRYPT, [Enable support for libgcrypt in libvncclient])
+AC_ARG_WITH(gcrypt,
+[  --without-gcrypt        disable support for gcrypt],,)
+AC_ARG_WITH(client-gcrypt,
+[  --without-client-gcrypt disable support for gcrypt in libvncclient],,)
+
+if test "x$with_gcrypt" != "xno"; then
+	AM_PATH_LIBGCRYPT(1.4.0, , with_client_gcrypt=no)
+	CFLAGS="$CFLAGS $LIBGCRYPT_CFLAGS"
+	LIBS="$LIBS $LIBGCRYPT_LIBS"
+	if test "x$with_client_gcrypt" != "xno"; then
+		AC_DEFINE(WITH_CLIENT_GCRYPT)
+	fi
+fi
+
 # Checks for GnuTLS
 AH_TEMPLATE(WITH_CLIENT_TLS, [Enable support for gnutls in libvncclient])
 AC_ARG_WITH(gnutls,
diff --git a/libvncclient/rfbproto.c b/libvncclient/rfbproto.c
index 010d08d..2de9891 100644
--- a/libvncclient/rfbproto.c
+++ b/libvncclient/rfbproto.c
@@ -51,6 +51,10 @@
 #include <stdarg.h>
 #include <time.h>
 
+#ifdef LIBVNCSERVER_WITH_CLIENT_GCRYPT
+#include <gcrypt.h>
+#endif
+
 #include "minilzo.h"
 #include "tls.h"
 
@@ -566,6 +570,7 @@ ReadSupportedSecurityType(rfbClient* client, uint32_t *result, rfbBool subAuth)
         rfbClientLog("%d) Received security type %d\n", loop, tAuth[loop]);
         if (flag) continue;
         if (tAuth[loop]==rfbVncAuth || tAuth[loop]==rfbNoAuth || tAuth[loop]==rfbMSLogon ||
+            tAuth[loop]==rfbARD ||
             (!subAuth && (tAuth[loop]==rfbTLS || tAuth[loop]==rfbVeNCrypt)))
         {
             if (!subAuth && client->clientAuthSchemes)
@@ -795,6 +800,208 @@ HandleMSLogonAuth(rfbClient *client)
   return TRUE;
 }
 
+#ifdef LIBVNCSERVER_WITH_CLIENT_GCRYPT
+static rfbBool
+rfbMpiToBytes(const gcry_mpi_t value, uint8_t *result, size_t size)
+{
+  gcry_error_t error;
+  size_t len;
+  int i;
+
+  error = gcry_mpi_print(GCRYMPI_FMT_USG, result, size, &len, value);
+  if (gcry_err_code(error) != GPG_ERR_NO_ERROR)
+  {
+    rfbClientLog("gcry_mpi_print error: %s\n", gcry_strerror(error));
+    return FALSE;
+  }
+  for (i=size-1;i>(int)size-1-(int)len;--i)
+    result[i] = result[i-size+len];
+  for (;i>=0;--i)
+    result[i] = 0;
+  return TRUE;
+}
+
+static rfbBool
+HandleARDAuth(rfbClient *client)
+{
+  uint8_t gen[2], len[2];
+  size_t keylen;
+  uint8_t *mod = NULL, *resp, *pub, *key, *shared;
+  gcry_mpi_t genmpi = NULL, modmpi = NULL, respmpi = NULL;
+  gcry_mpi_t privmpi = NULL, pubmpi = NULL, keympi = NULL;
+  gcry_md_hd_t md5 = NULL;
+  gcry_cipher_hd_t aes = NULL;
+  gcry_error_t error;
+  uint8_t userpass[128], ciphertext[128];
+  int passwordLen, usernameLen;
+  rfbCredential *cred = NULL;
+  rfbBool result = FALSE;
+
+  while (1)
+  {
+    if (!ReadFromRFBServer(client, (char *)gen, 2))
+      break;
+    if (!ReadFromRFBServer(client, (char *)len, 2))
+      break;
+
+    if (!client->GetCredential)
+    {
+      rfbClientLog("GetCredential callback is not set.\n");
+      break;
+    }
+    cred = client->GetCredential(client, rfbCredentialTypeUser);
+    if (!cred)
+    {
+      rfbClientLog("Reading credential failed\n");
+      break;
+    }
+
+    keylen = 256*len[0]+len[1];
+    mod = (uint8_t*)malloc(keylen*4);
+    if (!mod)
+    {
+      rfbClientLog("malloc out of memory\n");
+      break;
+    }
+    resp = mod+keylen;
+    pub = resp+keylen;
+    key = pub+keylen;
+
+    if (!ReadFromRFBServer(client, (char *)mod, keylen))
+      break;
+    if (!ReadFromRFBServer(client, (char *)resp, keylen))
+      break;
+
+    error = gcry_mpi_scan(&genmpi, GCRYMPI_FMT_USG, gen, 2, NULL);
+    if (gcry_err_code(error) != GPG_ERR_NO_ERROR)
+    {
+      rfbClientLog("gcry_mpi_scan error: %s\n", gcry_strerror(error));
+      break;
+    }
+    error = gcry_mpi_scan(&modmpi, GCRYMPI_FMT_USG, mod, keylen, NULL);
+    if (gcry_err_code(error) != GPG_ERR_NO_ERROR)
+    {
+      rfbClientLog("gcry_mpi_scan error: %s\n", gcry_strerror(error));
+      break;
+    }
+    error = gcry_mpi_scan(&respmpi, GCRYMPI_FMT_USG, resp, keylen, NULL);
+    if (gcry_err_code(error) != GPG_ERR_NO_ERROR)
+    {
+      rfbClientLog("gcry_mpi_scan error: %s\n", gcry_strerror(error));
+      break;
+    }
+
+    privmpi = gcry_mpi_new(keylen);
+    if (!privmpi)
+    {
+      rfbClientLog("gcry_mpi_new out of memory\n");
+      break;
+    }
+    gcry_mpi_randomize(privmpi, (keylen/8)*8, GCRY_STRONG_RANDOM);
+
+    pubmpi = gcry_mpi_new(keylen);
+    if (!pubmpi)
+    {
+      rfbClientLog("gcry_mpi_new out of memory\n");
+      break;
+    }
+    gcry_mpi_powm(pubmpi, genmpi, privmpi, modmpi);
+
+    keympi = gcry_mpi_new(keylen);
+    if (!keympi)
+    {
+      rfbClientLog("gcry_mpi_new out of memory\n");
+      break;
+    }
+    gcry_mpi_powm(keympi, respmpi, privmpi, modmpi);
+
+    if (!rfbMpiToBytes(pubmpi, pub, keylen))
+      break;
+    if (!rfbMpiToBytes(keympi, key, keylen))
+      break;
+
+    error = gcry_md_open(&md5, GCRY_MD_MD5, 0);
+    if (gcry_err_code(error) != GPG_ERR_NO_ERROR)
+    {
+      rfbClientLog("gcry_md_open error: %s\n", gcry_strerror(error));
+      break;
+    }
+    gcry_md_write(md5, key, keylen);
+    error = gcry_md_final(md5);
+    if (gcry_err_code(error) != GPG_ERR_NO_ERROR)
+    {
+      rfbClientLog("gcry_md_final error: %s\n", gcry_strerror(error));
+      break;
+    }
+    shared = gcry_md_read(md5, GCRY_MD_MD5);
+
+    passwordLen = strlen(cred->userCredential.password)+1;
+    usernameLen = strlen(cred->userCredential.username)+1;
+    if (passwordLen > sizeof(userpass)/2)
+      passwordLen = sizeof(userpass)/2;
+    if (usernameLen > sizeof(userpass)/2)
+      usernameLen = sizeof(userpass)/2;
+
+    gcry_randomize(userpass, sizeof(userpass), GCRY_STRONG_RANDOM);
+    memcpy(userpass, cred->userCredential.username, usernameLen);
+    memcpy(userpass+sizeof(userpass)/2, cred->userCredential.password, passwordLen);
+
+    error = gcry_cipher_open(&aes, GCRY_CIPHER_AES128, GCRY_CIPHER_MODE_ECB, 0);
+    if (gcry_err_code(error) != GPG_ERR_NO_ERROR)
+    {
+      rfbClientLog("gcry_cipher_open error: %s\n", gcry_strerror(error));
+      break;
+    }
+    error = gcry_cipher_setkey(aes, shared, 16);
+    if (gcry_err_code(error) != GPG_ERR_NO_ERROR)
+    {
+      rfbClientLog("gcry_cipher_setkey error: %s\n", gcry_strerror(error));
+      break;
+    }
+    error = gcry_cipher_encrypt(aes, ciphertext, sizeof(ciphertext), userpass, sizeof(userpass));
+    if (gcry_err_code(error) != GPG_ERR_NO_ERROR)
+    {
+      rfbClientLog("gcry_cipher_encrypt error: %s\n", gcry_strerror(error));
+      break;
+    }
+
+    if (!WriteToRFBServer(client, (char *)ciphertext, sizeof(ciphertext)))
+      break;
+    if (!WriteToRFBServer(client, (char *)pub, keylen))
+      break;
+
+    /* Handle the SecurityResult message */
+    if (!rfbHandleAuthResult(client))
+      break;
+
+    result = TRUE;
+    break;
+  }
+
+  if (cred)
+    FreeUserCredential(cred);
+  if (mod)
+    free(mod);
+  if (genmpi)
+    gcry_mpi_release(genmpi);
+  if (modmpi)
+    gcry_mpi_release(modmpi);
+  if (respmpi)
+    gcry_mpi_release(respmpi);
+  if (privmpi)
+    gcry_mpi_release(privmpi);
+  if (pubmpi)
+    gcry_mpi_release(pubmpi);
+  if (keympi)
+    gcry_mpi_release(keympi);
+  if (md5)
+    gcry_md_close(md5);
+  if (aes)
+    gcry_cipher_close(aes);
+  return result;
+}
+#endif
+
 /*
  * SetClientAuthSchemes.
  */
@@ -928,6 +1135,15 @@ InitialiseRFBConnection(rfbClient* client)
     if (!HandleMSLogonAuth(client)) return FALSE;
     break;
 
+  case rfbARD:
+#ifndef LIBVNCSERVER_WITH_CLIENT_GCRYPT
+    rfbClientLog("GCrypt support was not compiled in\n");
+    return FALSE;
+#else
+    if (!HandleARDAuth(client)) return FALSE;
+#endif
+    break;
+
   case rfbTLS:
 #ifndef LIBVNCSERVER_WITH_CLIENT_TLS
     rfbClientLog("TLS support was not compiled in\n");
diff --git a/rfb/rfbproto.h b/rfb/rfbproto.h
index 023528b..73d200a 100644
--- a/rfb/rfbproto.h
+++ b/rfb/rfbproto.h
@@ -286,6 +286,7 @@ typedef char rfbProtocolVersionMsg[13];	/* allow extra byte for null */
 #define rfbUltra 17
 #define rfbTLS 18
 #define rfbVeNCrypt 19
+#define rfbARD 30
 #define rfbMSLogon 0xfffffffa
 
 #define rfbVeNCryptPlain 256