1#!/usr/bin/expect --
2
3# ssh using the parms provided by the caller.  The benefit provided by this
4# program is that it will enter the password for you (i.e. non-interactively).
5
6# Description of arguments:
7# Arg0: The password.
8# Arg1: The ssh parm string.  This is the totality of ssh parms you wish to
9#       specify (e.g. userid, host, etc.).
10
11
12###############################################################################
13# Main
14
15  # Get arguments.
16  set password [lindex $argv 0]
17  set ssh_parms [lreplace $argv 0 0]
18
19  eval spawn ssh ${ssh_parms}
20
21  set timeout 30
22
23  set max_attempts 3
24
25  set attempts 0
26  while { 1 } {
27    incr attempts 1
28    expect {
29      -re "Offending RSA key in (.*?)\[\r\n\]" {
30        # We have been informed by ssh that we have a bad key.
31        # Retreive the file path and line number from the ssh output.
32        set fields [split $expect_out(1,string) ":"]
33        set file_path [lindex $fields 0]
34        set line_num [lindex $fields 1]
35        # Use sed to delete the bad key.
36        set cmd_buf "sed -i ${line_num}d ${file_path}"
37        puts "Issuing: ${cmd_buf}"
38        eval exec bash -c {$cmd_buf}
39        # Kill the failed spawned ssh process.
40        exec kill -9 [exp_pid]
41        # Start a new process now that our stale key problem is fixed.
42        eval spawn ssh ${ssh_parms}
43        continue
44      }
45      -re "assword:" {
46        send "$password\r"
47        break
48      }
49      -re "Are you sure you want to continue connecting" {
50        if { $attempts > $max_attempts } {
51          puts stderr "**ERROR** Exceeded $max_attempts attempts to ssh."
52          exit 1
53        }
54        send "yes\r"
55      }
56      timeout {
57        puts stderr "**ERROR** Timed out waiting for password prompt."
58        exit 1
59      }
60      eof {
61        puts stderr "**ERROR** End of data waiting for password prompt."
62        exit 1
63      }
64    }
65  }
66
67  set timeout 3
68  expect {
69    "Permission denied, please try again." {
70      puts ""
71      puts "**ERROR** Incorrect userid or password provided to this program."
72      exit 1
73    }
74  }
75
76  set timeout -1
77
78  # We don't ever expect to see this string.  This will keep this program
79  # running indefinitely.
80  set never_string "When in the course of human events, it becomes :"
81  if { [ catch {expect { "${never_string}" {send "whatever\r"} }} result ] } {
82    set child_died {expect:[ ]spawn[ ]id[ ]exp4[ ]not[ ]open}
83    if { [regexp -expanded ${child_died} $result] } {
84      # The child died.  This is not necessarily an error (for example, the
85      # user may have included a command string to run on the target).
86      exit 0
87    } else {
88      puts $result
89      exit 1
90    }
91  }
92
93  exit 0
94
95###############################################################################
96
97