Let user handle keyboard-interactive events

examples/keyboard_interactive_auth.py

@@ -0,0 +1,61 @@
+#!/usr/bin/python
+
+"""Example script for authentication with password"""
+
+from __future__ import print_function
+
+import argparse
+import socket
+import os
+import pwd
+import functools
+
+
+from ssh2.session import Session
+
+
+USERNAME = pwd.getpwuid(os.geteuid()).pw_name
+
+parser = argparse.ArgumentParser()
+
+parser.add_argument('password', help="User password")
+parser.add_argument('oauth', help="OAUTH key to use for authentication")
+parser.add_argument('cmd', help="Command to run")
+parser.add_argument('--host', dest='host',
+                    default='localhost',
+                    help='Host to connect to')
+parser.add_argument('--port', dest='port', default=22, help="Port to connect on", type=int)
+parser.add_argument('-u', dest='user', default=USERNAME, help="User name to authenticate as")
+
+
+def oauth_handler(name, instruction, prompts, password, oauth):
+    responses = []
+
+    for prompt in prompts:
+        if "Password:" in prompt:
+            responses.append(password)
+        if "One-time password (OATH) for" in prompt:
+            responses.append(oauth)
+
+    return responses
+
+def main():
+    args = parser.parse_args()
+
+    callback = functools.partial(oauth_handler,password=args.password,oauth=args.oauth)
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock.connect((args.host, args.port))
+    s = Session()
+    s.handshake(sock)
+    s.userauth_keyboardinteractive_callback(args.user, callback)
+    chan = s.open_session()
+    chan.execute(args.cmd)
+    size, data = chan.read()
+    while size > 0:
+        print(data)
+        size, data = chan.read()
+
+
+if __name__ == "__main__":
+    main()

ssh2/session.pyx

@@ -15,7 +15,8 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 
 from cpython cimport PyObject_AsFileDescriptor
-from libc.stdlib cimport malloc, free
+from libc.stdlib cimport calloc, malloc, free
+from libc.string cimport memcpy
 from libc.time cimport time_t
 from cython.operator cimport dereference as c_dereference
 
@@ -26,7 +27,7 @@ from exceptions import SessionHostKeyError, KnownHostError, \
 from listener cimport PyListener
 from sftp cimport PySFTP
 from publickey cimport PyPublicKeySystem
-from utils cimport to_bytes, to_str, handle_error_codes
+from utils cimport to_bytes, to_str, to_str_len, handle_error_codes
 from statinfo cimport StatInfo
 from knownhost cimport PyKnownHost
 from fileinfo cimport FileInfo
@@ -79,16 +80,25 @@ cdef void kbd_callback(const char *name, int name_len,
     py_sess = (<Session>c_dereference(abstract))
     if py_sess._kbd_callback is None:
         return
-    cdef bytes b_password = to_bytes(py_sess._kbd_callback())
-    cdef size_t _len = len(b_password)
-    cdef char *_password = b_password
-    cdef char *_password_copy
-    if num_prompts == 1:
-        _password_copy = <char *>malloc(sizeof(char) * _len)
-        for i in range(_len):
-            _password_copy[i] = _password[i]
-        responses[0].text = _password_copy
-        responses[0].length = _len
+
+    cdef list py_prompts = []
+    for i in range(num_prompts):
+        prompt_len = prompts[i].length
+        py_prompts.append(to_str_len(prompts[i].text,prompt_len))
+
+    cdef list py_responses = py_sess._kbd_callback(<bytes> name[:name_len], <bytes> instruction[:instruction_len], py_prompts)
+
+    cdef bytes response
+    for i in range(num_prompts):
+        response = to_bytes(py_responses[i])
+
+        _len = len(response)
+        _buff = <char *>calloc(sizeof(char), _len)
+        for j in range(_len):
+            _buff[j] = response[j]
+
+        responses[i].text = _buff
+        responses[i].length = _len
 
 
 cdef class Session:
@@ -313,6 +323,19 @@ cdef class Session:
                                      password not None):
         """Perform keyboard-interactive authentication
 
+        :param username: User name to authenticate.
+        :type username: str
+        :param password: Password
+        :type password: str
+        """
+        def passwd(*args,password=password):
+            return [password]
+        return self.userauth_keyboardinteractive_callback(username, passwd)
+
+    def userauth_keyboardinteractive_callback(self, username not None,
+                                     callback not None):
+        """Perform keyboard-interactive authentication
+
         :param username: User name to authenticate.
         :type username: str
         :param password: Password
@@ -322,10 +345,7 @@ cdef class Session:
         cdef bytes b_username = to_bytes(username)
         cdef const char *_username = b_username
 
-        def passwd():
-            return password
-
-        self._kbd_callback = passwd
+        self._kbd_callback = callback
         rc = c_ssh2.libssh2_userauth_keyboard_interactive(
             self._session, _username, &kbd_callback)
         self._kbd_callback = None