#! /usr/bin/python """ #+ # NAME: # ssh_to # PURPOSE: # Simplify login between accounts on subnet # CATEGORY: # ucsd/gen/python # CALLING SEQUENCE: # ssh_to <-init> <...> # INPUTS: # user@host account for which ssh access is needed # (if the user name on the remote host is # the same as on the account from which # ssh_to is executed then 'user@ can be # omitted. # OPTIONAL INPUT PARAMETERS: # -init if specified it must be the first command # line argument. Initializes ssh access # to the remote account (see PROCEDURE). # OUTPUTS: # (private/public key pair; updates of local 'identification' # file and remote 'authorization' file(s)) # OPTIONAL OUTPUT PARAMETERS: # CALLS: # tiny.is_there, tiny.args, tiny.start, tiny.run_cmd, tiny.keys # RESTRICTIONS: # > Assumes that ssh2 creates 2048 bit dsa keys # with key name id_dsa_2048_a for the private key # and id_dsa_2048_a.pub for the public key. # > Assumes that ~/.ssh2 already exists on the remote # machines. # > For the soft links to work ~/bin must be in the path. # EXAMPLE: # ssh_to -init user@host (initializes user@host) # user@host (logs into user@host) # PROCEDURE: # If -init is set: # 1. Check for private key of type id_dsa_2048_a_*. # 2. If the private key does not exist, then run # ssh-keygen2 to generate private key id_dsa_2048_a # and public key id_dsa_2048_a.pub. Rename the key # pair to id_dsa_2048_a_$RANDOM(.pub). # 3. Put private key in .ssh2/identification # 4. Loop over all hosts, and for each # a. put the public key in remote ~/.ssh2 directory, # b. put the name of the public key in remote ~/.ssh2/authorization. # c. put a link to ssh2_to in ~/bin # MODIFICATION HISTORY: # JUL-2004, Paul Hick (UCSD/CASS) # JAN-2004, Paul Hick (UCSD/CASS) # Converted from bash to Python. # FEB-2009, Paul Hick (UCSD/CASS; pphick@ucsd.edu) # Improved lookup of files with private keys. #- """ # If -init is not set then call ssh import os, sys, random from tiny import is_there, args, start, run_cmd, keys if __name__ == '__main__': say = 'ssh_to, ' verbose = is_there('-verbose', sys.argv) init = is_there('-init' , sys.argv) arg = args(sys.argv) ssh = 'ssh' bin = os.path.join(os.environ['HOME'],'bin') txt = os.path.join( bin, 'ssh_to.txt' ) ssh_bin = '' if not init: host = ((os.path.split(sys.argv[0])))[1] if os.path.isfile(txt): tmp = (open(txt,'r')).read() if host in tmp: pbeg = tmp.find(host) pbeg = tmp.find('=' ,pbeg) pend = tmp.find('\n',pbeg) ssh_bin = tmp[pbeg+1:pend] if ssh_bin == '': ssh_bin = start('-bin=', sys.argv) if ssh_bin == '': ssh = run_cmd( 'which '+ssh+' 2> /dev/null', verbose ) if ssh == '': print say+'ssh not found' sys.exit() ssh = (ssh.split('\n'))[0] else: ssh = os.path.join( ssh_bin, ssh ) if not os.path.isfile(ssh) : print say+ssh+'not found' if not init: tmp = [ssh, host] key = keys(sys.argv) if len(key ) > 0: tmp.extend(key) if len(arg) > 1: tmp.extend(arg[1:]) print say+ssh+' '+host os.execvp(ssh, tmp) # Transfer control (process does not return) tmp = run_cmd( ssh+' -V 2>&1', verbose ) open_ssh = tmp.find('OpenSSH') == 0 # Check for ~/.ssh2 directory. if open_ssh: ssh_dir = os.path.join( os.environ['HOME'], '.ssh' ) prefix = 'id_dsa' else: ssh_dir = os.path.join( os.environ['HOME'], '.ssh2' ) prefix = 'id_dsa_2048_a' if not os.path.isdir( ssh_dir ): print say+ssh_dir+' does not exist' sys.exit() os.chdir( ssh_dir ) private = [] for key in os.listdir('.'): if key.find(prefix) == 0: if os.path.splitext(key)[1] != '.pub': if os.path.exists( key+'.pub'): private.append(key) # Generate private key if it doesn't exist. if len(private) == 0: keygen = os.path.join((os.path.split(ssh))[0], 'ssh-keygen') print say+'generating key with '+keygen tmp = run_cmd( keygen+' -t dsa', verbose ) if open_ssh: private = prefix public = private+'.pub' else: random.seed() private = prefix+'_'+'%05d'%random.randint(1,99999) public = private+'.pub' os.rename(prefix , private) os.rename(prefix+'.pub' , public ) else: private = private[0] public = private+'.pub' print say+'using '+ssh+' with key '+private if open_ssh: auth = '.ssh/authorized_keys' val = (open(public,'r')).read() val = (val.split('\n'))[0] else: # Check wheter private key is already in .ssh2/identification # If not then add it. key = 'IdKey '+private if os.path.isfile( 'identification' ): tmp = (open('identification','r')).read() if tmp.find(key) == -1: tmp += key+'\n' else: tmp = '\n' (open('identification','w')).write(tmp) auth = '.ssh2/authorization' val = (open(public,'r')).read() key = 'Key '+public hosts = arg[1:] for host in hosts: print '\n\nSet up: '+host+'\n\n' # Copy public key into remote .ssh2 directory # Add line to .ssh2/authentication (if necessary) # Note that we assume that the remote .ssh2 directory exists. if open_ssh: cmd = ssh+' '+host + \ ' "' + \ 'touch '+auth+'; ' + \ 'grep \\"'+val+'\\" '+auth+' > /dev/null; '+ \ 'if [ \\$? == 0 ]; then exit; fi; ' + \ 'echo \\"'+val+'\\" >> '+auth + \ '"' else: cmd = 'cat '+public+' | ' + \ ssh+' '+host + \ ' "' + \ 'cat - > .ssh2/'+public+'; ' + \ 'touch '+auth+'; ' + \ 'grep \\"'+key+'\\" '+auth+'; '+ \ 'if [ \\$? == 0 ]; then exit; fi; ' + \ 'echo \\"'+key+'\\" >> '+auth + \ '"' run_cmd( cmd, verbose ) # Add soft link to $HOME/bin (if necessary) if not os.path.isdir( bin ): os.mkdir( bin ) tmp = os.path.join( bin, host ) if os.path.islink( tmp ): if not os.path.exists( tmp ): # Should remove broken link os.remove (tmp) if not os.path.islink( tmp ): os.symlink( sys.argv[0], tmp ) if ssh_bin != '': if os.path.isfile( txt ): tmp = (open(txt,'r')).read() if host in tmp: pbeg = tmp.find(host) pend = tmp.find('\n',pbeg) tmp = tmp[0:pbeg]+tmp[pend+1:] else: tmp = '' tmp += host+'='+ssh_bin+'\n' (open(txt,'w')).write(tmp) sys.exit()