1 files changed, 99 insertions, 0 deletions
diff --git a/Monitoring/src/main/python/Credential/SshKeygen.py b/Monitoring/src/main/python/Credential/SshKeygen.py
new file mode 100644
index 0000000..7998575
--- /dev/null
+++ b/Monitoring/src/main/python/Credential/SshKeygen.py
@@ -0,0 +1,99 @@
+from __future__ import with_statement
+'''
+Created on Jul 20, 2011
+
+@author: steger
+'''
+from M2Crypto import RSA
+from base64 import b64encode
+from os import chmod, path
+import stat
+
+# paramiko provides this functionality, so maybe we don't need this class. see paramiko.PKey
+
+class CannotSet(Exception):
+    pass
+
+class SshKeygen(object):
+    '''
+    Generates a pair of RSA keys.
+    Enables saving the keys to the file system.
+    '''
+    def __init__(self, bits = 1024, e = 65337):
+        '''
+        Initiates the pair of RSA keys
+        @param bits: the length of the keys in bits
+        @type bits: integer  
+        @param e: the exponent
+        @type e: integer  
+        '''
+        self.rsa = RSA.gen_key(bits, e, lambda: None)
+        
+    def _check_filename(self, filename):
+        if path.exists(filename):
+            raise Exception("File exists: %s" % filename)
+
+    def _get_private(self):
+        '''
+        @summary: return the private key in PEM format
+        @return: the private key in PEM format
+        @rtype: string
+        '''
+        return self.rsa.as_pem(cipher = None)
+
+    def _set_private(self, value):
+        raise CannotSet
+
+    def _del_private(self):
+        raise CannotSet
+    
+    @staticmethod
+    def _convert(rsa):
+        return b64encode('\x00\x00\x00\x07ssh-rsa%s%s' % (rsa.pub()[0], rsa.pub()[1]))
+
+    def _get_public(self):
+        '''
+        @summary: return the public key in base64 format conforming to the content of authorized_keys
+        @return: the public key in base64 format
+        @rtype: string
+        '''
+        return self._convert(self.rsa)
+
+    def _set_public(self, value):
+        raise CannotSet
+
+    def _del_public(self):
+        raise CannotSet
+
+    def save_private_key(self, filename):
+        '''
+        @summary: save the private key in the file system in a named file.
+        @param filename: the filename to store the private key.
+        @type filename: string  
+        '''
+        self._check_filename(filename)
+        self.rsa.save_key(filename, cipher = None)
+        chmod(filename, stat.S_IRUSR)
+                
+    def save_public_key(self, filename):
+        '''
+        @summary: save the public key in the file system in a named file.
+        @param filename: the filename to store the public key.
+        @type filename: string  
+        '''
+        self._check_filename(filename)
+        with open(filename, "w") as f:
+            f.write("ssh-rsa %s" % self.public)
+
+    @staticmethod            
+    def convert_key_from_file(filename):
+        '''
+        @summary: convert a private key stored in a file in PEM format and return the public key in base64 format conforming to the content of authorized_keys
+        @return: the public key in base64 format
+        @rtype: string
+        '''
+        return SshKeygen._convert( RSA.load_key(file = filename) )
+
+    public = property(_get_public,_set_public,_del_public)
+
+    private = property(_get_private,_set_private,_del_private)