Added support for libssh SSH SCP back-end

libssh is an alternative library to libssh2.
https://www.libssh.org/

That patch set also introduces support for ECDSA
ed25519 keys, as well as gssapi authentication.

Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>

13 files changed, 1626 insertions, 198 deletions

diff --git a/configure.ac b/configure.ac
index a72a612fb..8ae12067e 100755
--- a/configure.ac
+++ b/configure.ac
@@ -2716,8 +2716,15 @@ dnl Default to compiler & linker defaults for LIBSSH2 files & libraries.
 OPT_LIBSSH2=off
 AC_ARG_WITH(libssh2,dnl
 AC_HELP_STRING([--with-libssh2=PATH],[Where to look for libssh2, PATH points to the LIBSSH2 installation; when possible, set the PKG_CONFIG_PATH environment variable instead of using this option])
-AC_HELP_STRING([--without-libssh2], [disable LIBSSH2]),
-  OPT_LIBSSH2=$withval)
+AC_HELP_STRING([--with-libssh2], [enable LIBSSH2]),
+  OPT_LIBSSH2=$withval, OPT_LIBSSH2=no)
+
+
+OPT_LIBSSH=off
+AC_ARG_WITH(libssh,dnl
+AC_HELP_STRING([--with-libssh=PATH],[Where to look for libssh, PATH points to the LIBSSH installation; when possible, set the PKG_CONFIG_PATH environment variable instead of using this option])
+AC_HELP_STRING([--with-libssh], [enable LIBSSH]),
+  OPT_LIBSSH=$withval, OPT_LIBSSH=no)
 
 if test X"$OPT_LIBSSH2" != Xno; then
   dnl backup the pre-libssh2 variables
@@ -2792,6 +2799,79 @@ if test X"$OPT_LIBSSH2" != Xno; then
     CPPFLAGS=$CLEANCPPFLAGS
     LIBS=$CLEANLIBS
   fi
+elif test X"$OPT_LIBSSH" != Xno; then
+  dnl backup the pre-libssh variables
+  CLEANLDFLAGS="$LDFLAGS"
+  CLEANCPPFLAGS="$CPPFLAGS"
+  CLEANLIBS="$LIBS"
+
+  case "$OPT_LIBSSH" in
+  yes)
+    dnl --with-libssh (without path) used
+    CURL_CHECK_PKGCONFIG(libssh)
+
+    if test "$PKGCONFIG" != "no" ; then
+      LIB_SSH=`$PKGCONFIG --libs-only-l libssh`
+      LD_SSH=`$PKGCONFIG --libs-only-L libssh`
+      CPP_SSH=`$PKGCONFIG --cflags-only-I libssh`
+      version=`$PKGCONFIG --modversion libssh`
+      DIR_SSH=`echo $LD_SSH | $SED -e 's/-L//'`
+    fi
+
+    ;;
+  off)
+    dnl no --with-libssh option given, just check default places
+    ;;
+  *)
+    dnl use the given --with-libssh spot
+    PREFIX_SSH=$OPT_LIBSSH
+    ;;
+  esac
+
+  dnl if given with a prefix, we set -L and -I based on that
+  if test -n "$PREFIX_SSH"; then
+    LIB_SSH="-lssh"
+    LD_SSH=-L${PREFIX_SSH}/lib$libsuff
+    CPP_SSH=-I${PREFIX_SSH}/include
+    DIR_SSH=${PREFIX_SSH;}/lib$libsuff
+  fi
+
+  LDFLAGS="$LDFLAGS $LD_SSH"
+  CPPFLAGS="$CPPFLAGS $CPP_SSH"
+  LIBS="$LIB_SSH $LIBS"
+
+  AC_CHECK_LIB(ssh, ssh_new)
+
+  AC_CHECK_HEADERS(libssh/libssh.h,
+    curl_ssh_msg="enabled (libSSH)"
+    LIBSSH_ENABLED=1
+    AC_DEFINE(USE_LIBSSH, 1, [if libSSH is in use])
+    AC_SUBST(USE_LIBSSH, [1])
+  )
+
+  if test X"$OPT_LIBSSH" != Xoff &&
+     test "$LIBSSH_ENABLED" != "1"; then
+    AC_MSG_ERROR([libSSH libs and/or directories were not found where specified!])
+  fi
+
+  if test "$LIBSSH_ENABLED" = "1"; then
+    if test -n "$DIR_SSH"; then
+       dnl when the libssh shared libs were found in a path that the run-time
+       dnl linker doesn't search through, we need to add it to LD_LIBRARY_PATH
+       dnl to prevent further configure tests to fail due to this
+
+       if test "x$cross_compiling" != "xyes"; then
+         LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$DIR_SSH"
+         export LD_LIBRARY_PATH
+         AC_MSG_NOTICE([Added $DIR_SSH to LD_LIBRARY_PATH])
+       fi
+    fi
+  else
+    dnl no libssh, revert back to clean variables
+    LDFLAGS=$CLEANLDFLAGS
+    CPPFLAGS=$CLEANCPPFLAGS
+    LIBS=$CLEANLIBS
+  fi
 fi
 
 dnl **********************************************************************
@@ -4009,6 +4089,9 @@ if test "x$USE_LIBSSH2" = "x1"; then
   SUPPORT_PROTOCOLS="$SUPPORT_PROTOCOLS SCP"
   SUPPORT_PROTOCOLS="$SUPPORT_PROTOCOLS SFTP"
 fi
+if test "x$USE_LIBSSH" = "x1"; then
+  SUPPORT_PROTOCOLS="$SUPPORT_PROTOCOLS SCP"
+fi
 if test "x$CURL_DISABLE_RTSP" != "x1"; then
   SUPPORT_PROTOCOLS="$SUPPORT_PROTOCOLS RTSP"
 fi
diff --git a/include/curl/curl.h b/include/curl/curl.h
index 9ad5c20df..f4bf357bf 100644
--- a/include/curl/curl.h
+++ b/include/curl/curl.h
@@ -715,6 +715,7 @@ typedef enum {
 #define CURLSSH_AUTH_HOST      (1<<2) /* host key files */
 #define CURLSSH_AUTH_KEYBOARD  (1<<3) /* keyboard interactive */
 #define CURLSSH_AUTH_AGENT     (1<<4) /* agent (ssh-agent, pageant...) */
+#define CURLSSH_AUTH_GSSAPI    (1<<5) /* gssapi (kerberos, ...) */
 #define CURLSSH_AUTH_DEFAULT CURLSSH_AUTH_ANY
 
 #define CURLGSSAPI_DELEGATION_NONE        0      /* no delegation (default) */
@@ -727,7 +728,9 @@ enum curl_khtype {
   CURLKHTYPE_UNKNOWN,
   CURLKHTYPE_RSA1,
   CURLKHTYPE_RSA,
-  CURLKHTYPE_DSS
+  CURLKHTYPE_DSS,
+  CURLKHTYPE_ECDSA,
+  CURLKHTYPE_ED25519
 };
 
 struct curl_khkey {
diff --git a/lib/Makefile.inc b/lib/Makefile.inc
index 0a88b8eb8..61e80cf52 100644
--- a/lib/Makefile.inc
+++ b/lib/Makefile.inc
@@ -46,7 +46,7 @@ LIB_CFILES = file.c timeval.c base64.c hostip.c progress.c formdata.c   \
   http_digest.c md4.c md5.c http_negotiate.c inet_pton.c strtoofft.c    \
   strerror.c amigaos.c hostasyn.c hostip4.c hostip6.c hostsyn.c         \
   inet_ntop.c parsedate.c select.c tftp.c splay.c strdup.c socks.c      \
-  ssh.c curl_addrinfo.c socks_gssapi.c socks_sspi.c            \
+  ssh.c ssh-libssh.c curl_addrinfo.c socks_gssapi.c socks_sspi.c            \
   curl_sspi.c slist.c nonblock.c curl_memrchr.c imap.c pop3.c smtp.c    \
   pingpong.c rtsp.c curl_threads.c warnless.c hmac.c curl_rtmp.c        \
   openldap.c curl_gethostname.c gopher.c idn_win32.c                    \
@@ -54,7 +54,7 @@ LIB_CFILES = file.c timeval.c base64.c hostip.c progress.c formdata.c   \
   http_ntlm.c curl_ntlm_wb.c curl_ntlm_core.c curl_sasl.c rand.c        \
   curl_multibyte.c hostcheck.c conncache.c pipeline.c dotdot.c          \
   x509asn1.c http2.c smb.c curl_endian.c curl_des.c system_win32.c      \
-  mime.c sha256.c setopt.c
+  mime.c sha256.c setopt.c curl_path.c
 
 LIB_HFILES = arpa_telnet.h netrc.h file.h timeval.h hostip.h progress.h \
   formdata.h cookie.h http.h sendf.h ftp.h url.h dict.h if2ip.h         \
@@ -73,7 +73,8 @@ LIB_HFILES = arpa_telnet.h netrc.h file.h timeval.h hostip.h progress.h \
   curl_sasl.h curl_multibyte.h hostcheck.h conncache.h                  \
   curl_setup_once.h multihandle.h setup-vms.h pipeline.h dotdot.h       \
   x509asn1.h http2.h sigpipe.h smb.h curl_endian.h curl_des.h           \
-  curl_printf.h system_win32.h rand.h mime.h curl_sha256.h setopt.h
+  curl_printf.h system_win32.h rand.h mime.h curl_sha256.h setopt.h     \
+  curl_path.h
 
 LIB_RCFILES = libcurl.rc
 
diff --git a/lib/curl_path.c b/lib/curl_path.c
new file mode 100644
index 000000000..cd6592096
--- /dev/null
+++ b/lib/curl_path.c
@@ -0,0 +1,179 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#include <curl/curl.h>
+#include "curl_memory.h"
+#include "curl_path.h"
+#include "escape.h"
+#include "memdebug.h"
+
+/* figure out the path to work with in this particular request */
+CURLcode Curl_getworkingpath(struct connectdata *conn,
+                             char *homedir,  /* when SFTP is used */
+                             char **path) /* returns the  allocated
+                                             real path to work with */
+{
+  struct Curl_easy *data = conn->data;
+  char *real_path = NULL;
+  char *working_path;
+  size_t working_path_len;
+  CURLcode result =
+    Curl_urldecode(data, data->state.path, 0, &working_path,
+                   &working_path_len, FALSE);
+  if(result)
+    return result;
+
+  /* Check for /~/, indicating relative to the user's home directory */
+  if(conn->handler->protocol & CURLPROTO_SCP) {
+    real_path = malloc(working_path_len + 1);
+    if(real_path == NULL) {
+      free(working_path);
+      return CURLE_OUT_OF_MEMORY;
+    }
+    if((working_path_len > 3) && (!memcmp(working_path, "/~/", 3)))
+      /* It is referenced to the home directory, so strip the leading '/~/' */
+      memcpy(real_path, working_path + 3, 4 + working_path_len-3);
+    else
+      memcpy(real_path, working_path, 1 + working_path_len);
+  }
+  else if(conn->handler->protocol & CURLPROTO_SFTP) {
+    if((working_path_len > 1) && (working_path[1] == '~')) {
+      size_t homelen = strlen(homedir);
+      real_path = malloc(homelen + working_path_len + 1);
+      if(real_path == NULL) {
+        free(working_path);
+        return CURLE_OUT_OF_MEMORY;
+      }
+      /* It is referenced to the home directory, so strip the
+         leading '/' */
+      memcpy(real_path, homedir, homelen);
+      real_path[homelen] = '/';
+      real_path[homelen + 1] = '\0';
+      if(working_path_len > 3) {
+        memcpy(real_path + homelen + 1, working_path + 3,
+               1 + working_path_len -3);
+      }
+    }
+    else {
+      real_path = malloc(working_path_len + 1);
+      if(real_path == NULL) {
+        free(working_path);
+        return CURLE_OUT_OF_MEMORY;
+      }
+      memcpy(real_path, working_path, 1 + working_path_len);
+    }
+  }
+
+  free(working_path);
+
+  /* store the pointer for the caller to receive */
+  *path = real_path;
+
+  return CURLE_OK;
+}
+
+/* The get_pathname() function is being borrowed from OpenSSH sftp.c
+   version 4.6p1. */
+/*
+ * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+CURLcode Curl_get_pathname(const char **cpp, char **path)
+{
+  const char *cp = *cpp, *end;
+  char quot;
+  unsigned int i, j;
+  static const char WHITESPACE[] = " \t\r\n";
+
+  cp += strspn(cp, WHITESPACE);
+  if(!*cp) {
+    *cpp = cp;
+    *path = NULL;
+    return CURLE_QUOTE_ERROR;
+  }
+
+  *path = malloc(strlen(cp) + 1);
+  if(*path == NULL)
+    return CURLE_OUT_OF_MEMORY;
+
+  /* Check for quoted filenames */
+  if(*cp == '\"' || *cp == '\'') {
+    quot = *cp++;
+
+    /* Search for terminating quote, unescape some chars */
+    for(i = j = 0; i <= strlen(cp); i++) {
+      if(cp[i] == quot) {  /* Found quote */
+        i++;
+        (*path)[j] = '\0';
+        break;
+      }
+      if(cp[i] == '\0') {  /* End of string */
+        /*error("Unterminated quote");*/
+        goto fail;
+      }
+      if(cp[i] == '\\') {  /* Escaped characters */
+        i++;
+        if(cp[i] != '\'' && cp[i] != '\"' &&
+            cp[i] != '\\') {
+          /*error("Bad escaped character '\\%c'",
+              cp[i]);*/
+          goto fail;
+        }
+      }
+      (*path)[j++] = cp[i];
+    }
+
+    if(j == 0) {
+      /*error("Empty quotes");*/
+      goto fail;
+    }
+    *cpp = cp + i + strspn(cp + i, WHITESPACE);
+  }
+  else {
+    /* Read to end of filename */
+    end = strpbrk(cp, WHITESPACE);
+    if(end == NULL)
+      end = strchr(cp, '\0');
+    *cpp = end + strspn(end, WHITESPACE);
+
+    memcpy(*path, cp, end - cp);
+    (*path)[end - cp] = '\0';
+  }
+  return CURLE_OK;
+
+  fail:
+  Curl_safefree(*path);
+  return CURLE_QUOTE_ERROR;
+}
diff --git a/lib/curl_path.h b/lib/curl_path.h
new file mode 100644
index 000000000..3ce16eb88
--- /dev/null
+++ b/lib/curl_path.h
@@ -0,0 +1,45 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+#include <curl/curl.h>
+#include "urldata.h"
+
+#ifdef WIN32
+#  undef  PATH_MAX
+#  define PATH_MAX MAX_PATH
+#  ifndef R_OK
+#    define R_OK 4
+#  endif
+#endif
+
+#ifndef PATH_MAX
+#define PATH_MAX 1024 /* just an extra precaution since there are systems that
+                         have their definition hidden well */
+#endif
+
+CURLcode Curl_getworkingpath(struct connectdata *conn,
+                             char *homedir,
+                             char **path);
+
+CURLcode
+Curl_get_pathname(const char **cpp, char **path);
diff --git a/lib/easy.c b/lib/easy.c
index 5917db36a..72506488a 100644
--- a/lib/easy.c
+++ b/lib/easy.c
@@ -253,6 +253,13 @@ static CURLcode global_init(long flags, bool memoryfuncs)
   }
 #endif
 
+#if defined(USE_LIBSSH)
+  if(ssh_init()) {
+    DEBUGF(fprintf(stderr, "Error: libssh_init failed\n"));
+    return CURLE_FAILED_INIT;
+  }
+#endif
+
   if(flags & CURL_GLOBAL_ACK_EINTR)
     Curl_ack_eintr = 1;
 
@@ -330,6 +337,10 @@ void curl_global_cleanup(void)
   (void)libssh2_exit();
 #endif
 
+#if defined(USE_LIBSSH)
+  (void)ssh_finalize();
+#endif
+
   init_flags  = 0;
 }
 
diff --git a/lib/setopt.c b/lib/setopt.c
index 70466bffb..944d17347 100644
--- a/lib/setopt.c
+++ b/lib/setopt.c
@@ -2110,7 +2110,7 @@ static CURLcode setopt(struct Curl_easy *data, CURLoption option,
     data->set.proxy_ssl.primary.sessionid = data->set.ssl.primary.sessionid;
     break;
 
-#ifdef USE_LIBSSH2
+#if defined(USE_LIBSSH2) || defined(USE_LIBSSH)
     /* we only include SSH options if explicitly built to support SSH */
   case CURLOPT_SSH_AUTH_TYPES:
     data->set.ssh_auth_types = va_arg(param, long);
@@ -2161,7 +2161,6 @@ static CURLcode setopt(struct Curl_easy *data, CURLoption option,
     data->set.ssh_keyfunc_userp = va_arg(param, void *);
     break;
 #endif /* HAVE_LIBSSH2_KNOWNHOST_API */
-
 #endif /* USE_LIBSSH2 */
 
   case CURLOPT_HTTP_TRANSFER_DECODING:
diff --git a/lib/ssh-libssh.c b/lib/ssh-libssh.c
new file mode 100644
index 000000000..6c05f6d2d
--- /dev/null
+++ b/lib/ssh-libssh.c
@@ -0,0 +1,1234 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2017 Red Hat, Inc.
+ *
+ * Authors: Nikos Mavrogiannopoulos, Tomas Mraz, Stanislav Zidek, Robert Kolcun
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#ifdef USE_LIBSSH
+
+#ifdef HAVE_LIMITS_H
+#include <limits.h>
+#endif
+
+#include <libssh/libssh.h>
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef HAVE_UTSNAME_H
+#include <sys/utsname.h>
+#endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+#ifdef __VMS
+#include <in.h>
+#include <inet.h>
+#endif
+
+#if (defined(NETWARE) && defined(__NOVELL_LIBC__))
+#undef in_addr_t
+#define in_addr_t unsigned long
+#endif
+
+#include <curl/curl.h>
+#include "urldata.h"
+#include "sendf.h"
+#include "hostip.h"
+#include "progress.h"
+#include "transfer.h"
+#include "escape.h"
+#include "http.h"               /* for HTTP proxy tunnel stuff */
+#include "ssh.h"
+#include "url.h"
+#include "speedcheck.h"
+#include "getinfo.h"
+#include "strdup.h"
+#include "strcase.h"
+#include "vtls/vtls.h"
+#include "connect.h"
+#include "strerror.h"
+#include "inet_ntop.h"
+#include "parsedate.h"          /* for the week day and month names */
+#include "sockaddr.h"           /* required for Curl_sockaddr_storage */
+#include "strtoofft.h"
+#include "multiif.h"
+#include "select.h"
+#include "warnless.h"
+
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+#include "curl_path.h"
+
+/* Local functions: */
+static CURLcode myssh_connect(struct connectdata *conn, bool *done);
+static CURLcode myssh_multi_statemach(struct connectdata *conn,
+                                      bool *done);
+static CURLcode myssh_do_it(struct connectdata *conn, bool *done);
+
+static CURLcode scp_done(struct connectdata *conn,
+                         CURLcode, bool premature);
+static CURLcode scp_doing(struct connectdata *conn, bool *dophase_done);
+static CURLcode scp_disconnect(struct connectdata *conn,
+                               bool dead_connection);
+
+static int myssh_getsock(struct connectdata *conn, curl_socket_t *sock,
+                         int numsocks);
+
+static int myssh_perform_getsock(const struct connectdata *conn,
+                                 curl_socket_t *sock,
+                                 int numsocks);
+
+static CURLcode myssh_setup_connection(struct connectdata *conn);
+
+/*
+ * SCP protocol handler.
+ */
+
+const struct Curl_handler Curl_handler_scp = {
+  "SCP",                        /* scheme */
+  myssh_setup_connection,       /* setup_connection */
+  myssh_do_it,                  /* do_it */
+  scp_done,                     /* done */
+  ZERO_NULL,                    /* do_more */
+  myssh_connect,                /* connect_it */
+  myssh_multi_statemach,        /* connecting */
+  scp_doing,                    /* doing */
+  myssh_getsock,                /* proto_getsock */
+  myssh_getsock,                /* doing_getsock */
+  ZERO_NULL,                    /* domore_getsock */
+  myssh_perform_getsock,        /* perform_getsock */
+  scp_disconnect,               /* disconnect */
+  ZERO_NULL,                    /* readwrite */
+  ZERO_NULL,                    /* connection_check */
+  PORT_SSH,                     /* defport */
+  CURLPROTO_SCP,                /* protocol */
+  PROTOPT_DIRLOCK | PROTOPT_CLOSEACTION | PROTOPT_NOURLQUERY    /* flags */
+};
+
+/*
+ * SSH State machine related code
+ */
+/* This is the ONLY way to change SSH state! */
+static void state(struct connectdata *conn, sshstate nowstate)
+{
+  struct ssh_conn *sshc = &conn->proto.sshc;
+#if defined(DEBUGBUILD) && !defined(CURL_DISABLE_VERBOSE_STRINGS)
+  /* for debug purposes */
+  static const char *const names[] = {
+    "SSH_STOP",
+    "SSH_INIT",
+    "SSH_S_STARTUP",
+    "SSH_HOSTKEY",
+    "SSH_AUTHLIST",
+    "SSH_AUTH_PKEY_INIT",
+    "SSH_AUTH_PKEY",
+    "SSH_AUTH_PASS_INIT",
+    "SSH_AUTH_PASS",
+    "SSH_AUTH_AGENT_INIT",
+    "SSH_AUTH_AGENT_LIST",
+    "SSH_AUTH_AGENT",
+    "SSH_AUTH_HOST_INIT",
+    "SSH_AUTH_HOST",
+    "SSH_AUTH_KEY_INIT",
+    "SSH_AUTH_KEY",
+    "SSH_AUTH_GSSAPI",
+    "SSH_AUTH_DONE",
+    "SSH_SFTP_INIT",
+    "SSH_SFTP_REALPATH",
+    "SSH_SFTP_QUOTE_INIT",
+    "SSH_SFTP_POSTQUOTE_INIT",
+    "SSH_SFTP_QUOTE",
+    "SSH_SFTP_NEXT_QUOTE",
+    "SSH_SFTP_QUOTE_STAT",
+    "SSH_SFTP_QUOTE_SETSTAT",
+    "SSH_SFTP_QUOTE_SYMLINK",
+    "SSH_SFTP_QUOTE_MKDIR",
+    "SSH_SFTP_QUOTE_RENAME",
+    "SSH_SFTP_QUOTE_RMDIR",
+    "SSH_SFTP_QUOTE_UNLINK",
+    "SSH_SFTP_QUOTE_STATVFS",
+    "SSH_SFTP_GETINFO",
+    "SSH_SFTP_FILETIME",
+    "SSH_SFTP_TRANS_INIT",
+    "SSH_SFTP_UPLOAD_INIT",
+    "SSH_SFTP_CREATE_DIRS_INIT",
+    "SSH_SFTP_CREATE_DIRS",
+    "SSH_SFTP_CREATE_DIRS_MKDIR",
+    "SSH_SFTP_READDIR_INIT",
+    "SSH_SFTP_READDIR",
+    "SSH_SFTP_READDIR_LINK",
+    "SSH_SFTP_READDIR_BOTTOM",
+    "SSH_SFTP_READDIR_DONE",
+    "SSH_SFTP_DOWNLOAD_INIT",
+    "SSH_SFTP_DOWNLOAD_STAT",
+    "SSH_SFTP_CLOSE",
+    "SSH_SFTP_SHUTDOWN",
+    "SSH_SCP_TRANS_INIT",
+    "SSH_SCP_UPLOAD_INIT",
+    "SSH_SCP_DOWNLOAD_INIT",
+    "SSH_SCP_DOWNLOAD",
+    "SSH_SCP_DONE",
+    "SSH_SCP_SEND_EOF",
+    "SSH_SCP_WAIT_EOF",
+    "SSH_SCP_WAIT_CLOSE",
+    "SSH_SCP_CHANNEL_FREE",
+    "SSH_SESSION_DISCONNECT",
+    "SSH_SESSION_FREE",
+    "QUIT"
+  };
+
+
+  if(sshc->state != nowstate) {
+    infof(conn->data, "SSH %p state change from %s to %s\n",
+          (void *) sshc, names[sshc->state], names[nowstate]);
+  }
+#endif
+
+  sshc->state = nowstate;
+}
+
+/* Multiple options:
+ * 1. data->set.str[STRING_SSH_HOST_PUBLIC_KEY_MD5] is set with an MD5
+ *    hash (90s style auth, not sure we should have it here)
+ * 2. data->set.ssh_keyfunc callback is set. Then we do trust on first
+ *    use. We even save on knownhosts if CURLKHSTAT_FINE_ADD_TO_FILE
+ *    is returned by it.
+ * 3. none of the above. We only accept if it is present on known hosts.
+ *
+ * Returns SSH_OK or SSH_ERROR.
+ */
+static int myssh_is_known(struct connectdata *conn)
+{
+  int rc;
+  struct Curl_easy *data = conn->data;
+  struct ssh_conn *sshc = &conn->proto.sshc;
+  ssh_key pubkey;
+  size_t hlen;
+  unsigned char *hash = NULL;
+  char *base64 = NULL;
+  int vstate;
+  enum curl_khmatch keymatch;
+  struct curl_khkey foundkey;
+  curl_sshkeycallback func =
+    data->set.ssh_keyfunc;
+
+  rc = ssh_get_publickey(sshc->ssh_session, &pubkey);
+  if(rc != SSH_OK)
+    return rc;
+
+  if(data->set.str[STRING_SSH_HOST_PUBLIC_KEY_MD5]) {
+    rc = ssh_get_publickey_hash(pubkey, SSH_PUBLICKEY_HASH_MD5,
+                                &hash, &hlen);
+    if(rc != SSH_OK)
+      goto cleanup;
+
+    if(hlen != strlen(data->set.str[STRING_SSH_HOST_PUBLIC_KEY_MD5]) ||
+       memcmp(&data->set.str[STRING_SSH_HOST_PUBLIC_KEY_MD5], hash, hlen)) {
+          rc = SSH_ERROR;
+          goto cleanup;
+    }
+
+    rc = SSH_OK;
+    goto cleanup;
+  }
+
+  if(data->set.ssl.primary.verifyhost != TRUE) {
+    rc = SSH_OK;
+    goto cleanup;
+  }
+
+  vstate = ssh_is_server_known(sshc->ssh_session);
+  switch(vstate) {
+    case SSH_SERVER_KNOWN_OK:
+      keymatch = CURLKHMATCH_OK;
+    case SSH_SERVER_FILE_NOT_FOUND:
+    case SSH_SERVER_NOT_KNOWN:
+      keymatch = CURLKHMATCH_MISSING;
+    default:
+      keymatch = CURLKHMATCH_MISMATCH;
+  }
+
+  if(func) { /* use callback to determine action */
+    rc = ssh_pki_export_pubkey_base64(pubkey, &base64);
+    if(rc != SSH_OK)
+      goto cleanup;
+
+    foundkey.key = base64;
+    foundkey.len = strlen(base64);
+
+    switch(ssh_key_type(pubkey)) {
+      case SSH_KEYTYPE_RSA:
+        foundkey.keytype = CURLKHTYPE_RSA;
+        break;
+      case SSH_KEYTYPE_RSA1:
+        foundkey.keytype = CURLKHTYPE_RSA1;
+        break;
+      case SSH_KEYTYPE_ECDSA:
+        foundkey.keytype = CURLKHTYPE_ECDSA;
+        break;
+#if LIBSSH_VERSION_INT >= SSH_VERSION_INT(0,7,0)
+      case SSH_KEYTYPE_ED25519:
+        foundkey.keytype = CURLKHTYPE_ED25519;
+        break;
+#endif
+      case SSH_KEYTYPE_DSS:
+        foundkey.keytype = CURLKHTYPE_DSS;
+        break;
+      default:
+        rc = SSH_ERROR;
+        goto cleanup;
+    }
+
+    /* we don't have anything equivalent to knownkey. Always NULL */
+    rc = func(data, NULL, &foundkey, /* from the remote host */
+              keymatch, data->set.ssh_keyfunc_userp);
+
+    switch(rc) {
+      case CURLKHSTAT_FINE_ADD_TO_FILE:
+        rc = ssh_write_knownhost(sshc->ssh_session);
+        if(rc != SSH_OK) {
+          goto cleanup;
+        }
+        break;
+      case CURLKHSTAT_FINE:
+        break;
+      default: /* REJECT/DEFER */
+        rc = SSH_ERROR;
+        goto cleanup;
+    }
+  }
+  else {
+    if(keymatch != CURLKHMATCH_OK) {
+      rc = SSH_ERROR;
+      goto cleanup;
+    }
+  }
+  rc = SSH_OK;
+
+cleanup:
+  if(hash)
+    ssh_clean_pubkey_hash(&hash);
+  ssh_key_free(pubkey);
+  return rc;
+}
+
+#define MOVE_TO_ERROR_STATE(_r) { \
+  state(conn, SSH_SESSION_FREE); \
+  sshc->actualcode = _r; \
+  rc = SSH_ERROR; \
+  break; \
+}
+
+#define MOVE_TO_LAST_AUTH \
+  if(sshc->auth_methods & SSH_AUTH_METHOD_PASSWORD) { \
+    rc = SSH_OK; \
+    state(conn, SSH_AUTH_PASS_INIT); \
+    break; \
+  } \
+  else { \
+    MOVE_TO_ERROR_STATE(CURLE_LOGIN_DENIED); \
+  }
+
+#define MOVE_TO_SECONDARY_AUTH \
+  if(sshc->auth_methods & SSH_AUTH_METHOD_GSSAPI_MIC) { \
+    rc = SSH_OK; \
+    state(conn, SSH_AUTH_GSSAPI); \
+    break; \
+  } \
+  else { \
+    MOVE_TO_LAST_AUTH; \
+  }
+
+
+/*
+ * ssh_statemach_act() runs the SSH state machine as far as it can without
+ * blocking and without reaching the end.  The data the pointer 'block' points
+ * to will be set to TRUE if the libssh function returns SSH_AGAIN
+ * meaning it wants to be called again when the socket is ready
+ */
+static CURLcode myssh_statemach_act(struct connectdata *conn, bool *block)
+{
+  CURLcode result = CURLE_OK;
+  struct Curl_easy *data = conn->data;
+  struct SSHPROTO *protop = data->req.protop;
+  struct ssh_conn *sshc = &conn->proto.sshc;
+  int rc = SSH_NO_ERROR;
+  const char *err_msg;
+  *block = 0;                   /* we're not blocking by default */
+
+  do {
+
+    switch(sshc->state) {
+    case SSH_INIT:
+      sshc->secondCreateDirs = 0;
+      sshc->nextstate = SSH_NO_STATE;
+      sshc->actualcode = CURLE_OK;
+
+#if 0
+      ssh_set_log_level(SSH_LOG_PACKET);
+#endif
+
+      /* Set libssh to non-blocking, since everything internally is
+         non-blocking */
+      ssh_set_blocking(sshc->ssh_session, 0);
+
+      state(conn, SSH_S_STARTUP);
+      /* fall-through */
+
+    case SSH_S_STARTUP:
+      rc = ssh_connect(sshc->ssh_session);
+      if(rc == SSH_AGAIN)
+        break;
+
+      if(rc != SSH_OK) {
+        failf(data, "Failure establishing ssh session");
+        MOVE_TO_ERROR_STATE(CURLE_FAILED_INIT);
+      }
+
+      state(conn, SSH_HOSTKEY);
+
+      /* fall-through */
+    case SSH_HOSTKEY:
+
+      rc = myssh_is_known(conn);
+      if(rc != SSH_OK) {
+        MOVE_TO_ERROR_STATE(CURLE_PEER_FAILED_VERIFICATION);
+      }
+
+      state(conn, SSH_AUTHLIST);
+      /* fall through */
+    case SSH_AUTHLIST:{
+        sshc->authed = FALSE;
+
+        rc = ssh_userauth_none(sshc->ssh_session, NULL);
+        if(rc == SSH_AUTH_AGAIN) {
+          rc = SSH_AGAIN;
+          break;
+        }
+
+        if(rc == SSH_AUTH_SUCCESS) {
+          sshc->authed = TRUE;
+          infof(data, "Authenticated with none\n");
+          state(conn, SSH_AUTH_DONE);
+          break;
+        }
+        else if(rc == SSH_AUTH_ERROR) {
+          MOVE_TO_ERROR_STATE(CURLE_LOGIN_DENIED);
+        }
+
+        sshc->auth_methods = ssh_userauth_list(sshc->ssh_session, NULL);
+        if(sshc->auth_methods & SSH_AUTH_METHOD_PUBLICKEY) {
+          state(conn, SSH_AUTH_PKEY_INIT);
+        }
+        else if(sshc->auth_methods & SSH_AUTH_METHOD_GSSAPI_MIC) {
+          state(conn, SSH_AUTH_GSSAPI);
+        }
+        else if(sshc->auth_methods & SSH_AUTH_METHOD_PASSWORD) {
+          state(conn, SSH_AUTH_PASS_INIT);
+        }
+        else {                  /* unsupported authentication method */
+          MOVE_TO_ERROR_STATE(CURLE_LOGIN_DENIED);
+        }
+
+        break;
+      }
+    case SSH_AUTH_PKEY_INIT:
+      if(!(data->set.ssh_auth_types & CURLSSH_AUTH_PUBLICKEY)) {
+        MOVE_TO_SECONDARY_AUTH;
+      }
+
+      /* Two choices, (1) private key was given on CMD,
+       * (2) use the "default" keys. */
+      if(data->set.str[STRING_SSH_PRIVATE_KEY]) {
+        if(sshc->pubkey && !data->set.ssl.key_passwd) {
+          rc = ssh_userauth_try_publickey(sshc->ssh_session, NULL,
+                                          sshc->pubkey);
+          if(rc == SSH_AUTH_AGAIN) {
+            rc = SSH_AGAIN;
+            break;
+          }
+
+          if(rc != SSH_OK) {
+            MOVE_TO_SECONDARY_AUTH;
+          }
+        }
+
+        rc = ssh_pki_import_privkey_file(data->
+                                         set.str[STRING_SSH_PRIVATE_KEY],
+                                         data->set.ssl.key_passwd, NULL,
+                                         NULL, &sshc->privkey);
+        if(rc != SSH_OK) {
+          failf(data, "Could not load private key file %s",
+                data->set.str[STRING_SSH_PRIVATE_KEY]);
+          break;
+        }
+
+        state(conn, SSH_AUTH_PKEY);
+        break;
+
+      }
+      else {
+        infof(data, "Authentication using SSH public key file\n");
+
+        rc = ssh_userauth_publickey_auto(sshc->ssh_session, NULL,
+                                         data->set.ssl.key_passwd);
+        if(rc == SSH_AUTH_AGAIN) {
+          rc = SSH_AGAIN;
+          break;
+        }
+        if(rc == SSH_AUTH_SUCCESS) {
+          rc = SSH_OK;
+          sshc->authed = TRUE;
+          infof(data, "Completed public key authentication\n");
+          state(conn, SSH_AUTH_DONE);
+          break;
+        }
+
+        MOVE_TO_SECONDARY_AUTH;
+      }
+      break;
+    case SSH_AUTH_PKEY:
+      rc = ssh_userauth_publickey(sshc->ssh_session, NULL, sshc->privkey);
+      if(rc == SSH_AUTH_AGAIN) {
+        rc = SSH_AGAIN;
+        break;
+      }
+
+      if(rc == SSH_AUTH_SUCCESS) {
+        sshc->authed = TRUE;
+        infof(data, "Completed public key authentication\n");
+        state(conn, SSH_AUTH_DONE);
+        break;
+      }
+      else {
+        infof(data, "Failed public key authentication (rc: %d)\n", rc);
+        MOVE_TO_SECONDARY_AUTH;
+      }
+      break;
+
+    case SSH_AUTH_GSSAPI:
+      if(!(data->set.ssh_auth_types & CURLSSH_AUTH_GSSAPI)) {
+        MOVE_TO_LAST_AUTH;
+      }
+
+      rc = ssh_userauth_gssapi(sshc->ssh_session);
+      if(rc == SSH_AUTH_AGAIN) {
+        rc = SSH_AGAIN;
+        break;
+      }
+
+      if(rc == SSH_AUTH_SUCCESS) {
+        rc = SSH_OK;
+        sshc->authed = TRUE;
+        infof(data, "Completed gssapi authentication\n");
+        state(conn, SSH_AUTH_DONE);
+        break;
+      }
+
+      MOVE_TO_LAST_AUTH;
+      break;
+
+    case SSH_AUTH_PASS_INIT:
+      if(!(data->set.ssh_auth_types & CURLSSH_AUTH_PASSWORD)) {
+        /* Host key authentication is intentionally not implemented */
+        MOVE_TO_ERROR_STATE(CURLE_LOGIN_DENIED);
+      }
+      state(conn, SSH_AUTH_PASS);
+      /* fall through */
+
+    case SSH_AUTH_PASS:
+      rc = ssh_userauth_password(sshc->ssh_session, NULL, conn->passwd);
+      if(rc == SSH_AUTH_AGAIN) {
+        rc = SSH_AGAIN;
+        break;
+      }
+
+      if(rc == SSH_AUTH_SUCCESS) {
+        sshc->authed = TRUE;
+        infof(data, "Completed password authentication\n");
+        state(conn, SSH_AUTH_DONE);
+      }
+      else {
+        MOVE_TO_ERROR_STATE(CURLE_LOGIN_DENIED);
+      }
+      break;
+
+    case SSH_AUTH_DONE:
+      if(!sshc->authed) {
+        failf(data, "Authentication failure");
+        MOVE_TO_ERROR_STATE(CURLE_LOGIN_DENIED);
+        break;
+      }
+
+      /*
+       * At this point we have an authenticated ssh session.
+       */
+      infof(data, "Authentication complete\n");
+
+      Curl_pgrsTime(conn->data, TIMER_APPCONNECT);      /* SSH is connected */
+
+      conn->sockfd = ssh_get_fd(sshc->ssh_session);
+      conn->writesockfd = CURL_SOCKET_BAD;
+
+      infof(data, "SSH CONNECT phase done\n");
+      state(conn, SSH_STOP);
+      break;
+
+    case SSH_SCP_TRANS_INIT:
+      result = Curl_getworkingpath(conn, sshc->homedir, &protop->path);
+      if(result) {
+        sshc->actualcode = result;
+        state(conn, SSH_STOP);
+        break;
+      }
+
+      /* Functions from the SCP subsystem cannot handle/return SSH_AGAIN */
+      ssh_set_blocking(sshc->ssh_session, 1);
+
+      if(data->set.upload) {
+        if(data->state.infilesize < 0) {
+          failf(data, "SCP requires a known file size for upload");
+          sshc->actualcode = CURLE_UPLOAD_FAILED;
+          MOVE_TO_ERROR_STATE(CURLE_UPLOAD_FAILED);
+        }
+
+        sshc->scp_session =
+          ssh_scp_new(sshc->ssh_session, SSH_SCP_WRITE, protop->path);
+        state(conn, SSH_SCP_UPLOAD_INIT);
+      }
+      else {
+        sshc->scp_session =
+          ssh_scp_new(sshc->ssh_session, SSH_SCP_READ, protop->path);
+        state(conn, SSH_SCP_DOWNLOAD_INIT);
+      }
+
+      if(!sshc->scp_session) {
+        err_msg = ssh_get_error(sshc->ssh_session);
+        failf(conn->data, "%s", err_msg);
+        MOVE_TO_ERROR_STATE(CURLE_UPLOAD_FAILED);
+      }
+
+      break;
+
+    case SSH_SCP_UPLOAD_INIT:
+
+      rc = ssh_scp_init(sshc->scp_session);
+      if(rc != SSH_OK) {
+        err_msg = ssh_get_error(sshc->ssh_session);
+        failf(conn->data, "%s", err_msg);
+        MOVE_TO_ERROR_STATE(CURLE_UPLOAD_FAILED);
+      }
+
+      rc = ssh_scp_push_file(sshc->scp_session, protop->path,
+                             data->state.infilesize,
+                             (int)data->set.new_file_perms);
+      if(rc != SSH_OK) {
+        err_msg = ssh_get_error(sshc->ssh_session);
+        failf(conn->data, "%s", err_msg);
+        MOVE_TO_ERROR_STATE(CURLE_UPLOAD_FAILED);
+      }
+
+      /* upload data */
+      Curl_setup_transfer(conn, -1, data->req.size, FALSE, NULL,
+                          FIRSTSOCKET, NULL);
+
+      /* not set by Curl_setup_transfer to preserve keepon bits */
+      conn->sockfd = conn->writesockfd;
+
+      /* store this original bitmask setup to use later on if we can't
+         figure out a "real" bitmask */
+      sshc->orig_waitfor = data->req.keepon;
+
+      /* we want to use the _sending_ function even when the socket turns
+         out readable as the underlying libssh scp send function will deal
+         with both accordingly */
+      conn->cselect_bits = CURL_CSELECT_OUT;
+
+      state(conn, SSH_STOP);
+
+      break;
+
+    case SSH_SCP_DOWNLOAD_INIT:
+
+      rc = ssh_scp_init(sshc->scp_session);
+      if(rc != SSH_OK) {
+        err_msg = ssh_get_error(sshc->ssh_session);
+        failf(conn->data, "%s", err_msg);
+        MOVE_TO_ERROR_STATE(CURLE_COULDNT_CONNECT);
+      }
+      state(conn, SSH_SCP_DOWNLOAD);
+      /* fall through */
+
+    case SSH_SCP_DOWNLOAD:{
+        curl_off_t bytecount;
+
+        rc = ssh_scp_pull_request(sshc->scp_session);
+        if(rc != SSH_SCP_REQUEST_NEWFILE) {
+          err_msg = ssh_get_error(sshc->ssh_session);
+          failf(conn->data, "%s", err_msg);
+          MOVE_TO_ERROR_STATE(CURLE_REMOTE_FILE_NOT_FOUND);
+          break;
+        }
+
+        /* download data */
+        bytecount = ssh_scp_request_get_size(sshc->scp_session);
+        data->req.maxdownload = (curl_off_t) bytecount;
+        Curl_setup_transfer(conn, FIRSTSOCKET, bytecount, FALSE, NULL, -1,
+                            NULL);
+
+        /* not set by Curl_setup_transfer to preserve keepon bits */
+        conn->writesockfd = conn->sockfd;
+
+        /* we want to use the _receiving_ function even when the socket turns
+           out writableable as the underlying libssh recv function will deal
+           with both accordingly */
+        conn->cselect_bits = CURL_CSELECT_IN;
+
+        state(conn, SSH_STOP);
+        break;
+      }
+    case SSH_SCP_DONE:
+      if(data->set.upload)
+        state(conn, SSH_SCP_SEND_EOF);
+      else
+        state(conn, SSH_SCP_CHANNEL_FREE);
+      break;
+
+    case SSH_SCP_SEND_EOF:
+      if(sshc->scp_session) {
+        rc = ssh_scp_close(sshc->scp_session);
+        if(rc == SSH_AGAIN) {
+          /* Currently the ssh_scp_close handles waiting for EOF in
+           * blocking way.
+           */
+          break;
+        }
+        if(rc != SSH_OK) {
+          infof(data, "Failed to close libssh scp channel: %s\n",
+                ssh_get_error(sshc->ssh_session));
+        }
+      }
+
+      state(conn, SSH_SCP_CHANNEL_FREE);
+      break;
+
+    case SSH_SCP_CHANNEL_FREE:
+      if(sshc->scp_session) {
+        ssh_scp_free(sshc->scp_session);
+        sshc->scp_session = NULL;
+      }
+      DEBUGF(infof(data, "SCP DONE phase complete\n"));
+
+      ssh_set_blocking(sshc->ssh_session, 0);
+
+      state(conn, SSH_SESSION_DISCONNECT);
+      /* fall through */
+
+    case SSH_SESSION_DISCONNECT:
+      /* during weird times when we've been prematurely aborted, the channel
+         is still alive when we reach this state and we MUST kill the channel
+         properly first */
+      if(sshc->scp_session) {
+        ssh_scp_free(sshc->scp_session);
+        sshc->scp_session = NULL;
+      }
+
+      ssh_disconnect(sshc->ssh_session);
+
+      Curl_safefree(sshc->homedir);
+      conn->data->state.most_recent_ftp_entrypath = NULL;
+
+      state(conn, SSH_SESSION_FREE);
+      /* fall through */
+    case SSH_SESSION_FREE:
+      if(sshc->ssh_session) {
+        ssh_free(sshc->ssh_session);
+        sshc->ssh_session = NULL;
+      }
+
+      /* worst-case scenario cleanup */
+
+      DEBUGASSERT(sshc->ssh_session == NULL);
+      DEBUGASSERT(sshc->scp_session == NULL);
+
+      if(sshc->privkey)
+        ssh_key_free(sshc->privkey);
+      if(sshc->pubkey)
+        ssh_key_free(sshc->pubkey);
+
+      Curl_safefree(sshc->rsa_pub);
+      Curl_safefree(sshc->rsa);
+
+      Curl_safefree(sshc->quote_path1);
+      Curl_safefree(sshc->quote_path2);
+
+      Curl_safefree(sshc->homedir);
+
+      Curl_safefree(sshc->readdir_filename);
+      Curl_safefree(sshc->readdir_longentry);
+      Curl_safefree(sshc->readdir_line);
+      Curl_safefree(sshc->readdir_linkPath);
+
+      /* the code we are about to return */
+      result = sshc->actualcode;
+
+      memset(sshc, 0, sizeof(struct ssh_conn));
+
+      connclose(conn, "SSH session free");
+      sshc->state = SSH_SESSION_FREE;   /* current */
+      sshc->nextstate = SSH_NO_STATE;
+      state(conn, SSH_STOP);
+      break;
+
+    case SSH_QUIT:
+      /* fallthrough, just stop! */
+    default:
+      /* internal error */
+      sshc->nextstate = SSH_NO_STATE;
+      state(conn, SSH_STOP);
+      break;
+
+    }
+  } while(!rc && (sshc->state != SSH_STOP));
+
+
+  if(rc == SSH_AGAIN) {
+    /* we would block, we need to wait for the socket to be ready (in the
+       right direction too)! */
+    *block = TRUE;
+  }
+
+  return result;
+}
+
+
+/* called by the multi interface to figure out what socket(s) to wait for and
+   for what actions in the DO_DONE, PERFORM and WAITPERFORM states */
+static int myssh_perform_getsock(const struct connectdata *conn,
+                                 curl_socket_t *sock,  /* points to numsocks
+                                                          number of sockets */
+                                 int numsocks)
+{
+  int bitmap = GETSOCK_BLANK;
+  (void) numsocks;
+
+  sock[0] = conn->sock[FIRSTSOCKET];
+
+  if(conn->waitfor & KEEP_RECV)
+    bitmap |= GETSOCK_READSOCK(FIRSTSOCKET);
+
+  if(conn->waitfor & KEEP_SEND)
+    bitmap |= GETSOCK_WRITESOCK(FIRSTSOCKET);
+
+  return bitmap;
+}
+
+/* Generic function called by the multi interface to figure out what socket(s)
+   to wait for and for what actions during the DOING and PROTOCONNECT states*/
+static int myssh_getsock(struct connectdata *conn,
+                         curl_socket_t *sock,  /* points to numsocks
+                                                   number of sockets */
+                         int numsocks)
+{
+  /* if we know the direction we can use the generic *_getsock() function even
+     for the protocol_connect and doing states */
+  return myssh_perform_getsock(conn, sock, numsocks);
+}
+
+static void myssh_block2waitfor(struct connectdata *conn, bool block)
+{
+  struct ssh_conn *sshc = &conn->proto.sshc;
+  int dir;
+
+  /* If it didn't block, or nothing was returned by ssh_get_poll_flags
+   * have the original set */
+  conn->waitfor = sshc->orig_waitfor;
+
+  if(block) {
+    dir = ssh_get_poll_flags(sshc->ssh_session);
+    if(dir & SSH_READ_PENDING) {
+      /* translate the libssh2 define bits into our own bit defines */
+      conn->waitfor = KEEP_RECV;
+    }
+    else if(dir & SSH_WRITE_PENDING) {
+      conn->waitfor = KEEP_SEND;
+    }
+  }
+}
+
+/* called repeatedly until done from multi.c */
+static CURLcode myssh_multi_statemach(struct connectdata *conn,
+                                      bool *done)
+{
+  struct ssh_conn *sshc = &conn->proto.sshc;
+  CURLcode result = CURLE_OK;
+  bool block;    /* we store the status and use that to provide a ssh_getsock()
+                    implementation */
+
+  result = myssh_statemach_act(conn, &block);
+  *done = (sshc->state == SSH_STOP) ? TRUE : FALSE;
+  myssh_block2waitfor(conn, block);
+
+  return result;
+}
+
+static CURLcode myssh_block_statemach(struct connectdata *conn,
+                                      bool disconnect)
+{
+  struct ssh_conn *sshc = &conn->proto.sshc;
+  CURLcode result = CURLE_OK;
+  struct Curl_easy *data = conn->data;
+
+  while((sshc->state != SSH_STOP) && !result) {
+    bool block;
+    timediff_t left = 1000;
+    struct curltime now = Curl_now();
+
+    result = myssh_statemach_act(conn, &block);
+    if(result)
+      break;
+
+    if(!disconnect) {
+      if(Curl_pgrsUpdate(conn))
+        return CURLE_ABORTED_BY_CALLBACK;
+
+      result = Curl_speedcheck(data, now);
+      if(result)
+        break;
+
+      left = Curl_timeleft(data, NULL, FALSE);
+      if(left < 0) {
+        failf(data, "Operation timed out");
+        return CURLE_OPERATION_TIMEDOUT;
+      }
+    }
+
+    if(!result && block) {
+      curl_socket_t sock = conn->sock[FIRSTSOCKET];
+      curl_socket_t fd_read = CURL_SOCKET_BAD;
+      fd_read = sock;
+      /* wait for the socket to become ready */
+      (void) Curl_socket_check(fd_read, CURL_SOCKET_BAD,
+                               CURL_SOCKET_BAD, left > 1000 ? 1000 : left);
+    }
+
+  }
+
+  return result;
+}
+
+/*
+ * SSH setup connection
+ */
+static CURLcode myssh_setup_connection(struct connectdata *conn)
+{
+  struct SSHPROTO *ssh;
+
+  conn->data->req.protop = ssh = calloc(1, sizeof(struct SSHPROTO));
+  if(!ssh)
+    return CURLE_OUT_OF_MEMORY;
+
+  return CURLE_OK;
+}
+
+static Curl_recv scp_recv;
+static Curl_send scp_send;
+
+/*
+ * Curl_ssh_connect() gets called from Curl_protocol_connect() to allow us to
+ * do protocol-specific actions at connect-time.
+ */
+static CURLcode myssh_connect(struct connectdata *conn, bool *done)
+{
+  struct ssh_conn *ssh;
+  CURLcode result;
+  struct Curl_easy *data = conn->data;
+  int rc;
+
+  /* initialize per-handle data if not already */
+  if(!data->req.protop)
+    myssh_setup_connection(conn);
+
+  /* We default to persistent connections. We set this already in this connect
+     function to make the re-use checks properly be able to check this bit. */
+  connkeep(conn, "SSH default");
+
+  if(conn->handler->protocol & CURLPROTO_SCP) {
+    conn->recv[FIRSTSOCKET] = scp_recv;
+    conn->send[FIRSTSOCKET] = scp_send;
+  }
+  else
+    return CURLE_SSH;
+
+  ssh = &conn->proto.sshc;
+
+  ssh->ssh_session = ssh_new();
+  if(ssh->ssh_session == NULL) {
+    failf(data, "Failure initialising ssh session");
+    return CURLE_FAILED_INIT;
+  }
+
+  if(conn->user) {
+    infof(data, "User: %s\n", conn->user);
+    ssh_options_set(ssh->ssh_session, SSH_OPTIONS_USER, conn->user);
+  }
+
+  if(data->set.str[STRING_SSH_KNOWNHOSTS]) {
+    infof(data, "Known hosts: %s\n", data->set.str[STRING_SSH_KNOWNHOSTS]);
+    ssh_options_set(ssh->ssh_session, SSH_OPTIONS_KNOWNHOSTS,
+                    data->set.str[STRING_SSH_KNOWNHOSTS]);
+  }
+
+  ssh_options_set(ssh->ssh_session, SSH_OPTIONS_HOST, conn->host.name);
+  if(conn->remote_port)
+    ssh_options_set(ssh->ssh_session, SSH_OPTIONS_PORT,
+                    &conn->remote_port);
+
+  if(data->set.ssh_compression) {
+    ssh_options_set(ssh->ssh_session, SSH_OPTIONS_COMPRESSION,
+                    "zlib,zlib@openssh.com,none");
+  }
+
+  ssh->privkey = NULL;
+  ssh->pubkey = NULL;
+
+  if(data->set.str[STRING_SSH_PUBLIC_KEY]) {
+    rc = ssh_pki_import_pubkey_file(data->set.str[STRING_SSH_PUBLIC_KEY],
+                                    &ssh->pubkey);
+    if(rc != SSH_OK) {
+      failf(data, "Could not load public key file");
+      /* ignore */
+    }
+  }
+
+  /* we do not verify here, we do it at the state machine,
+   * after connection */
+
+  state(conn, SSH_INIT);
+
+  result = myssh_multi_statemach(conn, done);
+
+  return result;
+}
+
+/* called from multi.c while DOing */
+static CURLcode scp_doing(struct connectdata *conn, bool *dophase_done)
+{
+  CURLcode result;
+
+  result = myssh_multi_statemach(conn, dophase_done);
+
+  if(*dophase_done) {
+    DEBUGF(infof(conn->data, "DO phase is complete\n"));
+  }
+  return result;
+}
+
+/*
+ ***********************************************************************
+ *
+ * scp_perform()
+ *
+ * This is the actual DO function for SCP. Get a file according to
+ * the options previously setup.
+ */
+
+static
+CURLcode scp_perform(struct connectdata *conn,
+                     bool *connected, bool *dophase_done)
+{
+  CURLcode result = CURLE_OK;
+
+  DEBUGF(infof(conn->data, "DO phase starts\n"));
+
+  *dophase_done = FALSE;        /* not done yet */
+
+  /* start the first command in the DO phase */
+  state(conn, SSH_SCP_TRANS_INIT);
+
+  result = myssh_multi_statemach(conn, dophase_done);
+
+  *connected = conn->bits.tcpconnect[FIRSTSOCKET];
+
+  if(*dophase_done) {
+    DEBUGF(infof(conn->data, "DO phase is complete\n"));
+  }
+
+  return result;
+}
+
+static CURLcode myssh_do_it(struct connectdata *conn, bool *done)
+{
+  CURLcode result;
+  bool connected = 0;
+  struct Curl_easy *data = conn->data;
+  struct ssh_conn *sshc = &conn->proto.sshc;
+
+  *done = FALSE;                /* default to false */
+
+  data->req.size = -1;          /* make sure this is unknown at this point */
+
+  sshc->actualcode = CURLE_OK;  /* reset error code */
+  sshc->secondCreateDirs = 0;   /* reset the create dir attempt state
+                                   variable */
+
+  Curl_pgrsSetUploadCounter(data, 0);
+  Curl_pgrsSetDownloadCounter(data, 0);
+  Curl_pgrsSetUploadSize(data, -1);
+  Curl_pgrsSetDownloadSize(data, -1);
+
+  if(conn->handler->protocol & CURLPROTO_SCP)
+    result = scp_perform(conn, &connected, done);
+  else
+    result = CURLE_SSH;
+
+  return result;
+}
+
+/* BLOCKING, but the function is using the state machine so the only reason
+   this is still blocking is that the multi interface code has no support for
+   disconnecting operations that takes a while */
+static CURLcode scp_disconnect(struct connectdata *conn,
+                               bool dead_connection)
+{
+  CURLcode result = CURLE_OK;
+  struct ssh_conn *ssh = &conn->proto.sshc;
+  (void) dead_connection;
+
+  if(ssh->ssh_session) {
+    /* only if there's a session still around to use! */
+
+    state(conn, SSH_SESSION_DISCONNECT);
+
+    result = myssh_block_statemach(conn, TRUE);
+  }
+
+  return result;
+}
+
+/* generic done function for both SCP and SFTP called from their specific
+   done functions */
+static CURLcode myssh_done(struct connectdata *conn, CURLcode status)
+{
+  CURLcode result = CURLE_OK;
+  struct SSHPROTO *protop = conn->data->req.protop;
+
+  if(!status) {
+    /* run the state-machine
+
+       TODO: when the multi interface is used, this _really_ should be using
+       the ssh_multi_statemach function but we have no general support for
+       non-blocking DONE operations!
+     */
+    result = myssh_block_statemach(conn, FALSE);
+  }
+  else
+    result = status;
+
+  if(protop)
+    Curl_safefree(protop->path);
+  if(Curl_pgrsDone(conn))
+    return CURLE_ABORTED_BY_CALLBACK;
+
+  conn->data->req.keepon = 0;   /* clear all bits */
+  return result;
+}
+
+
+static CURLcode scp_done(struct connectdata *conn, CURLcode status,
+                         bool premature)
+{
+  (void) premature;             /* not used */
+
+  if(!status)
+    state(conn, SSH_SCP_DONE);
+
+  return myssh_done(conn, status);
+
+}
+
+static ssize_t scp_send(struct connectdata *conn, int sockindex,
+                        const void *mem, size_t len, CURLcode *err)
+{
+  int rc;
+  (void) sockindex; /* we only support SCP on the fixed known primary socket */
+  (void) err;
+
+  rc = ssh_scp_write(conn->proto.sshc.scp_session, mem, len);
+
+#if 0
+  /* The following code is misleading, mostly added as wishful thinking
+   * that libssh at some point will implement non-blocking ssh_scp_write/read.
+   * Currently rc can only be number of bytes read or SSH_ERROR. */
+  myssh_block2waitfor(conn, (rc == SSH_AGAIN) ? TRUE : FALSE);
+
+  if(rc == SSH_AGAIN) {
+    *err = CURLE_AGAIN;
+    return 0;
+  }
+  else
+#endif
+  if(rc != SSH_OK) {
+    *err = CURLE_SSH;
+    return -1;
+  }
+
+  return len;
+}
+
+static ssize_t scp_recv(struct connectdata *conn, int sockindex,
+                        char *mem, size_t len, CURLcode *err)
+{
+  ssize_t nread;
+  (void) err;
+  (void) sockindex; /* we only support SCP on the fixed known primary socket */
+
+  /* libssh returns int */
+  nread = ssh_scp_read(conn->proto.sshc.scp_session, mem, len);
+
+#if 0
+  /* The following code is misleading, mostly added as wishful thinking
+   * that libssh at some point will implement non-blocking ssh_scp_write/read.
+   * Currently rc can only be SSH_OK or SSH_ERROR. */
+
+  myssh_block2waitfor(conn, (nread == SSH_AGAIN) ? TRUE : FALSE);
+  if(nread == SSH_AGAIN) {
+    *err = CURLE_AGAIN;
+    nread = -1;
+  }
+#endif
+
+  return nread;
+}
+
+#endif                          /* USE_LIBSSH */
diff --git a/lib/ssh.c b/lib/ssh.c
index 2496e7cff..54f08edf7 100644
--- a/lib/ssh.c
+++ b/lib/ssh.c
@@ -87,21 +87,9 @@
 /* The last 3 #include files should be in this order */
 #include "curl_printf.h"
 #include "curl_memory.h"
+#include "curl_path.h"
 #include "memdebug.h"
 
-#ifdef WIN32
-#  undef  PATH_MAX
-#  define PATH_MAX MAX_PATH
-#  ifndef R_OK
-#    define R_OK 4
-#  endif
-#endif
-
-#ifndef PATH_MAX
-#define PATH_MAX 1024 /* just an extra precaution since there are systems that
-                         have their definition hidden well */
-#endif
-
 #if LIBSSH2_VERSION_NUM >= 0x010206
 /* libssh2_sftp_statvfs and friends were added in 1.2.6 */
 #define HAS_STATVFS_SUPPORT 1
@@ -120,16 +108,10 @@ static LIBSSH2_ALLOC_FUNC(my_libssh2_malloc);
 static LIBSSH2_REALLOC_FUNC(my_libssh2_realloc);
 static LIBSSH2_FREE_FUNC(my_libssh2_free);
 
-static CURLcode get_pathname(const char **cpp, char **path);
-
 static CURLcode ssh_connect(struct connectdata *conn, bool *done);
 static CURLcode ssh_multi_statemach(struct connectdata *conn, bool *done);
 static CURLcode ssh_do(struct connectdata *conn, bool *done);
 
-static CURLcode ssh_getworkingpath(struct connectdata *conn,
-                                   char *homedir, /* when SFTP is used */
-                                   char **path);
-
 static CURLcode scp_done(struct connectdata *conn,
                          CURLcode, bool premature);
 static CURLcode scp_doing(struct connectdata *conn,
@@ -410,70 +392,6 @@ static void state(struct connectdata *conn, sshstate nowstate)
   sshc->state = nowstate;
 }
 
-/* figure out the path to work with in this particular request */
-static CURLcode ssh_getworkingpath(struct connectdata *conn,
-                                   char *homedir,  /* when SFTP is used */
-                                   char **path) /* returns the  allocated
-                                                   real path to work with */
-{
-  struct Curl_easy *data = conn->data;
-  char *real_path = NULL;
-  char *working_path;
-  size_t working_path_len;
-  CURLcode result =
-    Curl_urldecode(data, data->state.path, 0, &working_path,
-                   &working_path_len, FALSE);
-  if(result)
-    return result;
-
-  /* Check for /~/, indicating relative to the user's home directory */
-  if(conn->handler->protocol & CURLPROTO_SCP) {
-    real_path = malloc(working_path_len + 1);
-    if(real_path == NULL) {
-      free(working_path);
-      return CURLE_OUT_OF_MEMORY;
-    }
-    if((working_path_len > 3) && (!memcmp(working_path, "/~/", 3)))
-      /* It is referenced to the home directory, so strip the leading '/~/' */
-      memcpy(real_path, working_path + 3, 4 + working_path_len-3);
-    else
-      memcpy(real_path, working_path, 1 + working_path_len);
-  }
-  else if(conn->handler->protocol & CURLPROTO_SFTP) {
-    if((working_path_len > 1) && (working_path[1] == '~')) {
-      size_t homelen = strlen(homedir);
-      real_path = malloc(homelen + working_path_len + 1);
-      if(real_path == NULL) {
-        free(working_path);
-        return CURLE_OUT_OF_MEMORY;
-      }
-      /* It is referenced to the home directory, so strip the
-         leading '/' */
-      memcpy(real_path, homedir, homelen);
-      real_path[homelen] = '/';
-      real_path[homelen + 1] = '\0';
-      if(working_path_len > 3) {
-        memcpy(real_path + homelen + 1, working_path + 3,
-               1 + working_path_len -3);
-      }
-    }
-    else {
-      real_path = malloc(working_path_len + 1);
-      if(real_path == NULL) {
-        free(working_path);
-        return CURLE_OUT_OF_MEMORY;
-      }
-      memcpy(real_path, working_path, 1 + working_path_len);
-    }
-  }
-
-  free(working_path);
-
-  /* store the pointer for the caller to receive */
-  *path = real_path;
-
-  return CURLE_OK;
-}
 
 #ifdef HAVE_LIBSSH2_KNOWNHOST_API
 static int sshkeycallback(struct Curl_easy *easy,
@@ -1184,7 +1102,7 @@ static CURLcode ssh_statemach_act(struct connectdata *conn, bool *block)
 
     case SSH_SFTP_QUOTE_INIT:
 
-      result = ssh_getworkingpath(conn, sshc->homedir, &sftp_scp->path);
+      result = Curl_getworkingpath(conn, sshc->homedir, &sftp_scp->path);
       if(result) {
         sshc->actualcode = result;
         state(conn, SSH_STOP);
@@ -1279,7 +1197,7 @@ static CURLcode ssh_statemach_act(struct connectdata *conn, bool *block)
          * also, every command takes at least one argument so we get that
          * first argument right now
          */
-        result = get_pathname(&cp, &sshc->quote_path1);
+        result = Curl_get_pathname(&cp, &sshc->quote_path1);
         if(result) {
           if(result == CURLE_OUT_OF_MEMORY)
             failf(data, "Out of memory");
@@ -1304,7 +1222,7 @@ static CURLcode ssh_statemach_act(struct connectdata *conn, bool *block)
 
           /* sshc->quote_path1 contains the mode to set */
           /* get the destination */
-          result = get_pathname(&cp, &sshc->quote_path2);
+          result = Curl_get_pathname(&cp, &sshc->quote_path2);
           if(result) {
             if(result == CURLE_OUT_OF_MEMORY)
               failf(data, "Out of memory");
@@ -1326,7 +1244,7 @@ static CURLcode ssh_statemach_act(struct connectdata *conn, bool *block)
           /* symbolic linking */
           /* sshc->quote_path1 is the source */
           /* get the destination */
-          result = get_pathname(&cp, &sshc->quote_path2);
+          result = Curl_get_pathname(&cp, &sshc->quote_path2);
           if(result) {
             if(result == CURLE_OUT_OF_MEMORY)
               failf(data, "Out of memory");
@@ -1351,7 +1269,7 @@ static CURLcode ssh_statemach_act(struct connectdata *conn, bool *block)
           /* rename file */
           /* first param is the source path */
           /* second param is the dest. path */
-          result = get_pathname(&cp, &sshc->quote_path2);
+          result = Curl_get_pathname(&cp, &sshc->quote_path2);
           if(result) {
             if(result == CURLE_OUT_OF_MEMORY)
               failf(data, "Out of memory");
@@ -2399,7 +2317,7 @@ static CURLcode ssh_statemach_act(struct connectdata *conn, bool *block)
       break;
 
     case SSH_SCP_TRANS_INIT:
-      result = ssh_getworkingpath(conn, sshc->homedir, &sftp_scp->path);
+      result = Curl_getworkingpath(conn, sshc->homedir, &sftp_scp->path);
       if(result) {
         sshc->actualcode = result;
         state(conn, SSH_STOP);
@@ -3307,93 +3225,6 @@ static ssize_t sftp_recv(struct connectdata *conn, int sockindex,
   return nread;
 }
 
-/* The get_pathname() function is being borrowed from OpenSSH sftp.c
-   version 4.6p1. */
-/*
- * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-static CURLcode
-get_pathname(const char **cpp, char **path)
-{
-  const char *cp = *cpp, *end;
-  char quot;
-  unsigned int i, j;
-  static const char WHITESPACE[] = " \t\r\n";
-
-  cp += strspn(cp, WHITESPACE);
-  if(!*cp) {
-    *cpp = cp;
-    *path = NULL;
-    return CURLE_QUOTE_ERROR;
-  }
-
-  *path = malloc(strlen(cp) + 1);
-  if(*path == NULL)
-    return CURLE_OUT_OF_MEMORY;
-
-  /* Check for quoted filenames */
-  if(*cp == '\"' || *cp == '\'') {
-    quot = *cp++;
-
-    /* Search for terminating quote, unescape some chars */
-    for(i = j = 0; i <= strlen(cp); i++) {
-      if(cp[i] == quot) {  /* Found quote */
-        i++;
-        (*path)[j] = '\0';
-        break;
-      }
-      if(cp[i] == '\0') {  /* End of string */
-        /*error("Unterminated quote");*/
-        goto fail;
-      }
-      if(cp[i] == '\\') {  /* Escaped characters */
-        i++;
-        if(cp[i] != '\'' && cp[i] != '\"' &&
-            cp[i] != '\\') {
-          /*error("Bad escaped character '\\%c'",
-              cp[i]);*/
-          goto fail;
-        }
-      }
-      (*path)[j++] = cp[i];
-    }
-
-    if(j == 0) {
-      /*error("Empty quotes");*/
-      goto fail;
-    }
-    *cpp = cp + i + strspn(cp + i, WHITESPACE);
-  }
-  else {
-    /* Read to end of filename */
-    end = strpbrk(cp, WHITESPACE);
-    if(end == NULL)
-      end = strchr(cp, '\0');
-    *cpp = end + strspn(end, WHITESPACE);
-
-    memcpy(*path, cp, end - cp);
-    (*path)[end - cp] = '\0';
-  }
-  return CURLE_OK;
-
-  fail:
-  Curl_safefree(*path);
-  return CURLE_QUOTE_ERROR;
-}
-
-
 static const char *sftp_libssh2_strerror(int err)
 {
   switch(err) {
diff --git a/lib/ssh.h b/lib/ssh.h
index b350dcf3a..4c204423d 100644
--- a/lib/ssh.h
+++ b/lib/ssh.h
@@ -24,9 +24,11 @@
 
 #include "curl_setup.h"
 
-#ifdef HAVE_LIBSSH2_H
+#if defined(HAVE_LIBSSH2_H)
 #include <libssh2.h>
 #include <libssh2_sftp.h>
+#elif defined(HAVE_LIBSSH_LIBSSH_H)
+#include <libssh/libssh.h>
 #endif /* HAVE_LIBSSH2_H */
 
 /****************************************************************************
@@ -51,6 +53,7 @@ typedef enum {
   SSH_AUTH_HOST,
   SSH_AUTH_KEY_INIT,
   SSH_AUTH_KEY,
+  SSH_AUTH_GSSAPI,
   SSH_AUTH_DONE,
   SSH_SFTP_INIT,
   SSH_SFTP_REALPATH,   /* Last state in SSH-CONNECT */
@@ -86,6 +89,7 @@ typedef enum {
   SSH_SCP_TRANS_INIT, /* First state in SCP-DO */
   SSH_SCP_UPLOAD_INIT,
   SSH_SCP_DOWNLOAD_INIT,
+  SSH_SCP_DOWNLOAD,
   SSH_SCP_DONE,
   SSH_SCP_SEND_EOF,
   SSH_SCP_WAIT_EOF,
@@ -109,7 +113,8 @@ struct SSHPROTO {
    struct */
 struct ssh_conn {
   const char *authlist;       /* List of auth. methods, managed by libssh2 */
-#ifdef USE_LIBSSH2
+
+  /* common */
   const char *passphrase;     /* pass-phrase to use */
   char *rsa_pub;              /* path name */
   char *rsa;                  /* path name */
@@ -120,14 +125,11 @@ struct ssh_conn {
   struct curl_slist *quote_item; /* for the quote option */
   char *quote_path1;          /* two generic pointers for the QUOTE stuff */
   char *quote_path2;
-  LIBSSH2_SFTP_ATTRIBUTES quote_attrs; /* used by the SFTP_QUOTE state */
+
   bool acceptfail;            /* used by the SFTP_QUOTE (continue if
                                  quote command fails) */
   char *homedir;              /* when doing SFTP we figure out home dir in the
                                  connect phase */
-
-  /* Here's a set of struct members used by the SFTP_READDIR state */
-  LIBSSH2_SFTP_ATTRIBUTES readdir_attrs;
   char *readdir_filename;
   char *readdir_longentry;
   int readdir_len, readdir_totalLen, readdir_currLen;
@@ -139,11 +141,25 @@ struct ssh_conn {
                                    second attempt has been made to change
                                    to/create a directory */
   char *slash_pos;              /* used by the SFTP_CREATE_DIRS state */
+
+  int orig_waitfor;             /* default READ/WRITE bits wait for */
+
+#if defined(USE_LIBSSH)
+/* our variables */
+  ssh_key privkey;
+  ssh_key pubkey;
+  int auth_methods;
+  ssh_session ssh_session;
+  ssh_scp scp_session;
+#elif defined(USE_LIBSSH2)
+  LIBSSH2_SFTP_ATTRIBUTES quote_attrs; /* used by the SFTP_QUOTE state */
+
+  /* Here's a set of struct members used by the SFTP_READDIR state */
+  LIBSSH2_SFTP_ATTRIBUTES readdir_attrs;
   LIBSSH2_SESSION *ssh_session; /* Secure Shell session */
   LIBSSH2_CHANNEL *ssh_channel; /* Secure Shell channel handle */
   LIBSSH2_SFTP *sftp_session;   /* SFTP handle */
   LIBSSH2_SFTP_HANDLE *sftp_handle;
-  int orig_waitfor;             /* default READ/WRITE bits wait for */
 
 #ifdef HAVE_LIBSSH2_AGENT_API
   LIBSSH2_AGENT *ssh_agent;     /* proxy to ssh-agent/pageant */
@@ -156,10 +172,16 @@ struct ssh_conn {
 #ifdef HAVE_LIBSSH2_KNOWNHOST_API
   LIBSSH2_KNOWNHOSTS *kh;
 #endif
-#endif /* USE_LIBSSH2 */
+#endif /* USE_LIBSSH */
 };
 
-#ifdef USE_LIBSSH2
+#if defined(USE_LIBSSH)
+
+#define CURL_LIBSSH_VERSION ssh_version(0)
+
+extern const struct Curl_handler Curl_handler_scp;
+
+#elif defined(USE_LIBSSH2)
 
 /* Feature detection based on version numbers to better work with
    non-configure platforms */
@@ -190,6 +212,14 @@ struct ssh_conn {
 #define HAVE_LIBSSH2_SESSION_HANDSHAKE 1
 #endif
 
+#ifdef HAVE_LIBSSH2_VERSION
+/* get it run-time if possible */
+#define CURL_LIBSSH2_VERSION libssh2_version(0)
+#else
+/* use build-time if run-time not possible */
+#define CURL_LIBSSH2_VERSION LIBSSH2_VERSION
+#endif
+
 extern const struct Curl_handler Curl_handler_scp;
 extern const struct Curl_handler Curl_handler_sftp;
 
diff --git a/lib/url.c b/lib/url.c
index 0cc77f9fa..731e46fea 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -196,8 +196,11 @@ static const struct Curl_handler * const protocols[] = {
   &Curl_handler_tftp,
 #endif
 
-#ifdef USE_LIBSSH2
+#if defined(USE_LIBSSH2) || defined(USE_LIBSSH)
   &Curl_handler_scp,
+#endif
+
+#if defined(USE_LIBSSH2)
   &Curl_handler_sftp,
 #endif
 
diff --git a/lib/urldata.h b/lib/urldata.h
index 2052a0299..ed6bbb4f0 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -1410,7 +1410,7 @@ enum dupstring {
   STRING_RTSP_SESSION_ID, /* Session ID to use */
   STRING_RTSP_STREAM_URI, /* Stream URI for this request */
   STRING_RTSP_TRANSPORT,  /* Transport for this session */
-#ifdef USE_LIBSSH2
+#if defined(USE_LIBSSH2) || defined(USE_LIBSSH)
   STRING_SSH_PRIVATE_KEY, /* path to the private key file for auth */
   STRING_SSH_PUBLIC_KEY,  /* path to the public key file for auth */
   STRING_SSH_HOST_PUBLIC_KEY_MD5, /* md5 of host public key in ascii hex */
diff --git a/lib/version.c b/lib/version.c
index 79cc0bba4..f0861ea7a 100644
--- a/lib/version.c
+++ b/lib/version.c
@@ -26,6 +26,7 @@
 #include "urldata.h"
 #include "vtls/vtls.h"
 #include "http2.h"
+#include "ssh.h"
 #include "curl_printf.h"
 
 #ifdef USE_ARES
@@ -176,6 +177,11 @@ char *curl_version(void)
   left -= len;
   ptr += len;
 #endif
+#ifdef USE_LIBSSH
+  len = snprintf(ptr, left, " libssh/%s", CURL_LIBSSH_VERSION);
+  left -= len;
+  ptr += len;
+#endif
 #ifdef USE_NGHTTP2
   len = Curl_http2_ver(ptr, left);
   left -= len;
@@ -264,7 +270,7 @@ static const char * const protocols[] = {
 #ifndef CURL_DISABLE_RTSP
   "rtsp",
 #endif
-#ifdef USE_LIBSSH2
+#if defined(USE_LIBSSH) || defined(USE_LIBSSH2)
   "scp",
 #endif
 #ifdef USE_LIBSSH2
@@ -379,7 +385,7 @@ static curl_version_info_data version_info = {
 curl_version_info_data *curl_version_info(CURLversion stamp)
 {
   static bool initialized;
-#ifdef USE_LIBSSH2
+#if defined(USE_LIBSSH) || defined(USE_LIBSSH2)
   static char ssh_buffer[80];
 #endif
 #ifdef USE_SSL
@@ -431,9 +437,12 @@ curl_version_info_data *curl_version_info(CURLversion stamp)
 #endif /* _LIBICONV_VERSION */
 #endif
 
-#ifdef USE_LIBSSH2
+#if defined(USE_LIBSSH2)
   snprintf(ssh_buffer, sizeof(ssh_buffer), "libssh2/%s", LIBSSH2_VERSION);
   version_info.libssh_version = ssh_buffer;
+#elif defined(USE_LIBSSH)
+  snprintf(ssh_buffer, sizeof(ssh_buffer), "libssh/%s", CURL_LIBSSH_VERSION);
+  version_info.libssh_version = ssh_buffer;
 #endif
 
 #ifdef HAVE_BROTLI