# 
# add_file "fs_sftp.py"
# 
# patch "fs.py"
#  from [f571e9b863841b0cb2a55ff7e528cfc5991781e1]
#    to [05141f5122b18b6601bf0a33a3834ae48f6c3309]
# 
# patch "fs_sftp.py"
#  from []
#    to [67ebc9831df0ee859488fd2118383358061e7ce3]
# 
========================================================================
--- fs.py	f571e9b863841b0cb2a55ff7e528cfc5991781e1
+++ fs.py	05141f5122b18b6601bf0a33a3834ae48f6c3309
@@ -14,6 +14,9 @@
     elif scheme in ("http", "https", "ftp"):
         import fs_http
         return fs_http.HTTPReadableFS(url)
+    elif scheme == "sftp":
+        import fs_sftp
+        return fs_sftp.SFTPReadableFS(host, path)
     else:
         raise BadURL, url
 
@@ -21,6 +24,9 @@
     (scheme, host, path, param, query, frag) = urlparse(url, "file")
     if scheme == "file":
         return LocalWriteableFs(path)
+    elif scheme == "sftp":
+        import fs_sftp
+        return fs_sftp.SFTPWriteableFS(host, path)
     else:
         raise BadURL, url
 
@@ -116,16 +122,16 @@
             f.seek(offset)
             yield ((offset, length), f.read(length))
 
+class LocalWriteableFs(LocalReadableFS, WriteableFS):
+    def open_append(self, filename):
+        return open(self._fname(filename), "ab")
+
     def size(self, filename):
         try:
             return os.stat(self._fname(filename)).st_size
         except OSError:
             return 0
 
-class LocalWriteableFs(LocalReadableFS, WriteableFS):
-    def open_append(self, filename):
-        return open(self._fname(filename), "ab")
-
     def put(self, filenames):
         for fn, data in filenames.iteritems():
             tmpname = self._fname("__tmp")
========================================================================
--- fs_sftp.py	
+++ fs_sftp.py	67ebc9831df0ee859488fd2118383358061e7ce3
@@ -0,0 +1,142 @@
+# we need paramiko for sftp protocol support
+import paramiko
+import getpass
+import fs
+import os.path
+
+# All of this heavily cribbed from demo{,_simple}.py in the paramiko
+# distribution, which is LGPL.
+def load_host_keys():
+    # this file won't exist on windows, but windows doesn't have a standard
+    # location for this file anyway.
+    filename = os.path.expanduser('~/.ssh/known_hosts')
+    keys = {}
+    try:
+        f = open(filename, 'r')
+    except Exception, e:
+        print '*** Unable to open host keys file (%s)' % filename
+        return
+    for line in f:
+        keylist = line.split(' ')
+        if len(keylist) != 3:
+            continue
+        hostlist, keytype, key = keylist
+        hosts = hostlist.split(',')
+        for host in hosts:
+            if not keys.has_key(host):
+                keys[host] = {}
+            if keytype == 'ssh-rsa':
+                keys[host][keytype] = paramiko.RSAKey(data=base64.decodestring(key))
+            elif keytype == 'ssh-dss':
+                keys[host][keytype] = paramiko.DSSKey(data=base64.decodestring(key))
+    f.close()
+    return keys
+
+def get_user_password_host_port(hostspec):
+    username, password, hostname, port = None, None, None
+    if hostspec.find("@") >= 0:
+        userspec, hostspec = hostspec.split("@")
+        if userspec.find(":") >= 0:
+            username, password = userspec.split(":")
+        else:
+            username = userspec
+    if hostspec.find(":") >= 0:
+        hostname, port = hostspec.split(":")
+    else:
+        hostname = hostspec
+        port = 22
+    assert None not in (hostname, port)
+    if username is None:
+        username = getpass.getuser()
+    # FIXME: support agents etc. (see demo.py in paramiko dist)
+    if password is None:
+        password = getpass.getpass("Password for address@hidden: " % (username, hostname))
+    return username, password, hostname
+
+def get_host_key(hostname):
+    hkeys = load_host_keys()
+    if hkeys.has_key(hostname):
+        return hkeys[hostname].values()[0]
+    else:
+        return None
+
+class SFTPReadableFS(fs.ReadableFS):
+    def __init__(self, hostspec, path):
+        self.dir = path
+        username, password, hostname, port = get_user_password_host_port(hostspec)
+        hostkey = get_host_key(hostname)
+        self.transport = paramiko.Transport((hostname, port))
+        self.transport.connect(username=username, password=password,
+                               hostkey=hostkey)
+        self.client = t.open_sftp_client()
+        
+    def _fname(self, filename):
+        return os.path.join(self.dir, filename)
+
+    def open_read(self, filename):
+        return self.client.open(self._fname(filename), "rb")
+
+    def fetch(self, filenames):
+        files = {}
+        for fn in filenames:
+            try:
+                f = self.open_read(fn)
+                files[fn] = f.read()
+                f.close()
+            except IOError:
+                files[fn] = None
+        return files
+
+    def fetch_bytes(self, filename, bytes):
+        f = self.open_read(filename)
+        for offset, length in bytes:
+            f.seek(offset)
+            yield ((offset, length), f.read(length))
+
+class SFTPWriteableFS(SFTPReadableFS, fs.WriteableFS):
+    def open_append(self, filename):
+        return self.client.open(self._fname(filename), "ab")
+
+    def size(self, filename):
+        return self.client.stat(self._fname(filename)).st_size
+
+    def put(self, filenames):
+        for fn, data in filenames.iteritems():
+            tmpname = self._fname("__tmp")
+            tmph = self.client.open(tmpname, "wb")
+            tmph.write(data)
+            tmph.close()
+            self.client.rename(tmpname, self._fname(fn))
+
+    def rollback_interrupted_puts(self, filenames):
+        # for now, we assume we have atomic put
+        pass
+
+    def mkdir(self, filename):
+        try:
+            self.client.mkdir(self._fname(filename))
+        except OSError:
+            return 0
+        return 1
+
+    def rmdir(self, filename):
+        self.client.rmdir(self._fname(filename))
+
+    def ensure_dir(self):
+        try:
+            self.client.stat(self._fname(""))
+            return
+        except OSError:
+            pass  # fall through to actually create dir
+        pieces = []
+        rest = self.dir
+        while rest:
+            (rest, next_piece) = os.path.split(rest)
+            pieces.insert(0, next_piece)
+        sofar = ""
+        for piece in pieces:
+            sofar = os.path.join(sofar, piece)
+            try:
+                self.client.mkdir(sofar)
+            except OSError:
+                pass