flush input buffers before accepting stdin

6 files changed, 72 insertions, 32 deletions

diff --git a/src/lib/Bcfg2/Client/Frame.py b/src/lib/Bcfg2/Client/Frame.py
index 64460ea66..53180ab68 100644
--- a/src/lib/Bcfg2/Client/Frame.py
+++ b/src/lib/Bcfg2/Client/Frame.py
@@ -1,8 +1,10 @@
 """ Frame is the Client Framework that verifies and installs entries,
 and generates statistics. """
 
+import os
 import sys
 import time
+import select
 import fnmatch
 import logging
 import Bcfg2.Client.Tools
@@ -160,6 +162,9 @@ class Frame(object):
                 iprompt = entry.get('qtext')
             else:
                 iprompt = prompt % (entry.tag, entry.get('name'))
+            # flush input buffer
+            while len(select.select([sys.stdin.fileno()], [], [], 0.0)[0]) > 0:
+                os.read(sys.stdin.fileno(), 4096)
             try:
                 ans = input(iprompt.encode(sys.stdout.encoding, 'replace'))
                 if ans in ['y', 'Y']:
diff --git a/src/lib/Bcfg2/Client/Tools/Action.py b/src/lib/Bcfg2/Client/Tools/Action.py
index 7726da94c..b1a897c81 100644
--- a/src/lib/Bcfg2/Client/Tools/Action.py
+++ b/src/lib/Bcfg2/Client/Tools/Action.py
@@ -1,5 +1,8 @@
 """Action driver"""
 
+import os
+import sys
+import select
 import Bcfg2.Client.Tools
 from Bcfg2.Client.Frame import matches_white_list, passes_black_list
 from Bcfg2.Compat import input  # pylint: disable=W0622
@@ -33,6 +36,10 @@ class Action(Bcfg2.Client.Tools.Tool):
             if self.setup['interactive']:
                 prompt = ('Run Action %s, %s: (y/N): ' %
                           (entry.get('name'), entry.get('command')))
+                # flush input buffer
+                while len(select.select([sys.stdin.fileno()], [], [],
+                                        0.0)[0]) > 0:
+                    os.read(sys.stdin.fileno(), 4096)
                 ans = input(prompt)
                 if ans not in ['y', 'Y']:
                     return False
diff --git a/src/lib/Bcfg2/Client/Tools/__init__.py b/src/lib/Bcfg2/Client/Tools/__init__.py
index 4022692be..927b25ba8 100644
--- a/src/lib/Bcfg2/Client/Tools/__init__.py
+++ b/src/lib/Bcfg2/Client/Tools/__init__.py
@@ -1,7 +1,9 @@
 """This contains all Bcfg2 Tool modules"""
 
 import os
+import sys
 import stat
+import select
 from subprocess import Popen, PIPE
 import Bcfg2.Client.XML
 from Bcfg2.Compat import input, walk_packages  # pylint: disable=W0622
@@ -373,6 +375,10 @@ class SvcTool(Tool):
                     if self.setup['interactive']:
                         prompt = ('Restart service %s?: (y/N): ' %
                                   entry.get('name'))
+                        # flush input buffer
+                        while len(select.select([sys.stdin.fileno()], [], [],
+                                                0.0)[0]) > 0:
+                            os.read(sys.stdin.fileno(), 4096)
                         ans = input(prompt)
                         if ans not in ['y', 'Y']:
                             continue
diff --git a/src/lib/Bcfg2/Server/Admin/Init.py b/src/lib/Bcfg2/Server/Admin/Init.py
index 869dc1aca..14065980d 100644
--- a/src/lib/Bcfg2/Server/Admin/Init.py
+++ b/src/lib/Bcfg2/Server/Admin/Init.py
@@ -1,11 +1,13 @@
 """ Interactively initialize a new repository. """
-import getpass
+
 import os
+import sys
+import stat
+import select
 import random
 import socket
-import stat
 import string
-import sys
+import getpass
 import subprocess
 
 import Bcfg2.Server.Admin
@@ -85,6 +87,14 @@ OS_LIST = [('Red Hat/Fedora/RHEL/RHAS/Centos', 'redhat'),
            ('Arch', 'arch')]
 
 
+def safe_input(prompt):
+    """ input() that flushes the input buffer before accepting input """
+    # flush input buffer
+    while len(select.select([sys.stdin.fileno()], [], [], 0.0)[0]) > 0:
+        os.read(sys.stdin.fileno(), 4096)
+    return input(prompt)
+
+
 def gen_password(length):
     """Generates a random alphanumeric password with length characters."""
     chars = string.letters + string.digits
@@ -116,8 +126,8 @@ def create_conf(confpath, confdata):
     """ create the config file """
     # Don't overwrite existing bcfg2.conf file
     if os.path.exists(confpath):
-        result = input("\nWarning: %s already exists. "
-                       "Overwrite? [y/N]: " % confpath)
+        result = safe_input("\nWarning: %s already exists. "
+                            "Overwrite? [y/N]: " % confpath)
         if result not in ['Y', 'y']:
             print("Leaving %s unchanged" % confpath)
             return
@@ -186,8 +196,8 @@ class Init(Bcfg2.Server.Admin.Mode):
 
     def _prompt_hostname(self):
         """Ask for the server hostname."""
-        data = input("What is the server's hostname [%s]: " %
-                     socket.getfqdn())
+        data = safe_input("What is the server's hostname [%s]: " %
+                          socket.getfqdn())
         if data != '':
             self.data['shostname'] = data
         else:
@@ -195,21 +205,21 @@ class Init(Bcfg2.Server.Admin.Mode):
 
     def _prompt_config(self):
         """Ask for the configuration file path."""
-        newconfig = input("Store Bcfg2 configuration in [%s]: " %
-                          self.configfile)
+        newconfig = safe_input("Store Bcfg2 configuration in [%s]: " %
+                               self.configfile)
         if newconfig != '':
             self.data['configfile'] = os.path.abspath(newconfig)
 
     def _prompt_repopath(self):
         """Ask for the repository path."""
         while True:
-            newrepo = input("Location of Bcfg2 repository [%s]: " %
+            newrepo = safe_input("Location of Bcfg2 repository [%s]: " %
                             self.data['repopath'])
             if newrepo != '':
                 self.data['repopath'] = os.path.abspath(newrepo)
             if os.path.isdir(self.data['repopath']):
-                response = input("Directory %s exists. Overwrite? [y/N]:" %
-                                 self.data['repopath'])
+                response = safe_input("Directory %s exists. Overwrite? [y/N]:"
+                                      % self.data['repopath'])
                 if response.lower().strip() == 'y':
                     break
             else:
@@ -225,8 +235,8 @@ class Init(Bcfg2.Server.Admin.Mode):
 
     def _prompt_server(self):
         """Ask for the server name."""
-        newserver = input("Input the server location [%s]: " %
-                          self.data['server_uri'])
+        newserver = safe_input("Input the server location [%s]: " %
+                               self.data['server_uri'])
         if newserver != '':
             self.data['server_uri'] = newserver
 
@@ -238,7 +248,7 @@ class Init(Bcfg2.Server.Admin.Mode):
         prompt += ': '
         while True:
             try:
-                osidx = int(input(prompt))
+                osidx = int(safe_input(prompt))
                 self.data['os_sel'] = OS_LIST[osidx - 1][1]
                 break
             except ValueError:
@@ -248,27 +258,28 @@ class Init(Bcfg2.Server.Admin.Mode):
         """Ask for the key details (country, state, and location)."""
         print("The following questions affect SSL certificate generation.")
         print("If no data is provided, the default values are used.")
-        newcountry = input("Country name (2 letter code) for certificate: ")
+        newcountry = safe_input("Country name (2 letter code) for "
+                                "certificate: ")
         if newcountry != '':
             if len(newcountry) == 2:
                 self.data['country'] = newcountry
             else:
                 while len(newcountry) != 2:
-                    newcountry = input("2 letter country code (eg. US): ")
+                    newcountry = safe_input("2 letter country code (eg. US): ")
                     if len(newcountry) == 2:
                         self.data['country'] = newcountry
                         break
         else:
             self.data['country'] = 'US'
 
-        newstate = input("State or Province Name (full name) for "
-                         "certificate: ")
+        newstate = safe_input("State or Province Name (full name) for "
+                              "certificate: ")
         if newstate != '':
             self.data['state'] = newstate
         else:
             self.data['state'] = 'Illinois'
 
-        newlocation = input("Locality Name (eg, city) for certificate: ")
+        newlocation = safe_input("Locality Name (eg, city) for certificate: ")
         if newlocation != '':
             self.data['location'] = newlocation
         else:
@@ -277,12 +288,12 @@ class Init(Bcfg2.Server.Admin.Mode):
     def _prompt_keypath(self):
         """ Ask for the key pair location.  Try to use sensible
         defaults depending on the OS """
-        keypath = input("Path where Bcfg2 server private key will be created "
-                        "[%s]: " % self.data['keypath'])
+        keypath = safe_input("Path where Bcfg2 server private key will be "
+                             "created [%s]: " % self.data['keypath'])
         if keypath:
             self.data['keypath'] = keypath
-        certpath = input("Path where Bcfg2 server cert will be created"
-                         "[%s]: " % self.data['certpath'])
+        certpath = safe_input("Path where Bcfg2 server cert will be created"
+                              "[%s]: " % self.data['certpath'])
         if certpath:
             self.data['certpath'] = certpath
 
diff --git a/src/lib/Bcfg2/Server/Admin/Pull.py b/src/lib/Bcfg2/Server/Admin/Pull.py
index e41652205..130e85b67 100644
--- a/src/lib/Bcfg2/Server/Admin/Pull.py
+++ b/src/lib/Bcfg2/Server/Admin/Pull.py
@@ -1,8 +1,10 @@
 """ Retrieves entries from clients and integrates the information into
 the repository """
 
-import getopt
+import os
 import sys
+import getopt
+import select
 import Bcfg2.Server.Admin
 from Bcfg2.Compat import input  # pylint: disable=W0622
 
@@ -99,6 +101,10 @@ class Pull(Bcfg2.Server.Admin.MetadataCore):
                 else:
                     print(" => host entry: %s" % (choice.hostname))
 
+                # flush input buffer
+                while len(select.select([sys.stdin.fileno()], [], [],
+                                        0.0)[0]) > 0:
+                    os.read(sys.stdin.fileno(), 4096)
                 ans = input("Use this entry? [yN]: ") in ['y', 'Y']
                 if ans:
                     return choice
diff --git a/src/sbin/bcfg2-crypt b/src/sbin/bcfg2-crypt
index 0693b430c..961a8dc58 100755
--- a/src/sbin/bcfg2-crypt
+++ b/src/sbin/bcfg2-crypt
@@ -4,6 +4,7 @@
 import os
 import sys
 import copy
+import select
 import logging
 import lxml.etree
 import Bcfg2.Logger
@@ -31,7 +32,7 @@ class Encryptor(object):
         self.passphrase = None
         self.pname = None
         self.logger = logging.getLogger(self.__class__.__name__)
-        
+
     def get_encrypted_filename(self, plaintext_filename):
         """ get the name of the file encrypted data should be written to """
         return plaintext_filename
@@ -67,7 +68,7 @@ class Encryptor(object):
 
         if self.setup['passphrase']:
             self.pname = self.setup['passphrase']
-                
+
         if self.pname:
             if self.setup.cfp.has_option("encryption", self.pname):
                 self.passphrase = self.setup.cfp.get("encryption",
@@ -182,7 +183,7 @@ class Encryptor(object):
             self.logger.error("Error getting encrypted data from %s: %s" %
                               (fname, err))
             return False
-        
+
         try:
             return self.unchunk(plaintext, crypted)
         except EncryptionChunkingError:
@@ -317,10 +318,14 @@ class PropertiesEncryptor(Encryptor):
                 print(lxml.etree.tostring(
                     elt,
                     xml_declaration=False).decode("UTF-8").strip())
+                # flush input buffer
+                while len(select.select([sys.stdin.fileno()], [], [],
+                                        0.0)[0]) > 0:
+                    os.read(sys.stdin.fileno(), 4096)
                 ans = input("Encrypt this element? [y/N] ")
                 if not ans.lower().startswith("y"):
                     elements.remove(element)
-                
+
         # this is not a good use of a generator, but we need to
         # generate the full list of elements in order to ensure that
         # some exist before we know what to return
@@ -386,11 +391,11 @@ def main():  # pylint: disable=R0912,R0915
         elif setup['interactive']:
             logger.error("Cannot decrypt interactively")
             setup['interactive'] = False
-    
+
     if setup['cfg']:
         if setup['properties']:
             logger.error("You cannot specify both --cfg and --properties")
-            raise SystemExit(1)        
+            raise SystemExit(1)
         if setup['xpath']:
             logger.error("Specifying --xpath with --cfg is nonsensical, "
                          "ignoring --xpath")
@@ -411,7 +416,7 @@ def main():  # pylint: disable=R0912,R0915
         if not os.path.exists(fname):
             logger.error("%s does not exist, skipping" % fname)
             continue
-        
+
         # figure out if we need to encrypt this as a Properties file
         # or as a Cfg file
         props = False