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