"""An object-oriented interface to .netrc files."""
# Module and documentation by Eric S. Raymond, 21 Dec 1998
import os, stat
__all__ = ["netrc", "NetrcParseError"]
class NetrcParseError(Exception):
"""Exception raised on syntax errors in the .netrc file."""
def __init__(self, msg, filename=None, lineno=None):
self.filename = filename
self.lineno = lineno
self.msg = msg
Exception.__init__(self, msg)
def __str__(self):
return "%s (%s, line %s)" % (self.msg, self.filename, self.lineno)
class _netrclex:
def __init__(self, fp):
self.lineno = 1
self.instream = fp
self.whitespace = "\n\t\r "
self.pushback = []
def _read_char(self):
ch = self.instream.read(1)
if ch == "\n":
self.lineno += 1
return ch
def get_token(self):
if self.pushback:
return self.pushback.pop(0)
token = ""
fiter = iter(self._read_char, "")
for ch in fiter:
if ch in self.whitespace:
continue
if ch == '"':
for ch in fiter:
if ch == '"':
return token
elif ch == "\\":
ch = self._read_char()
token += ch
else:
if ch == "\\":
ch = self._read_char()
token += ch
for ch in fiter:
if ch in self.whitespace:
return token
elif ch == "\\":
ch = self._read_char()
token += ch
return token
def push_token(self, token):
self.pushback.append(token)
class netrc:
def __init__(self, file=None):
default_netrc = file is None
if file is None:
file = os.path.join(os.path.expanduser("~"), ".netrc")
self.hosts = {}
self.macros = {}
try:
with open(file, encoding="utf-8") as fp:
self._parse(file, fp, default_netrc)
except UnicodeDecodeError:
with open(file, encoding="locale") as fp:
self._parse(file, fp, default_netrc)
def _parse(self, file, fp, default_netrc):
lexer = _netrclex(fp)
while 1:
# Look for a machine, default, or macdef top-level keyword
saved_lineno = lexer.lineno
toplevel = tt = lexer.get_token()
if not tt:
break
elif tt[0] == '#':
if lexer.lineno == saved_lineno and len(tt) == 1:
lexer.instream.readline()
continue
elif tt == 'machine':
entryname = lexer.get_token()
elif tt == 'default':
entryname = 'default'
elif tt == 'macdef':
entryname = lexer.get_token()
self.macros[entryname] = []
while 1:
line = lexer.instream.readline()
if not line:
raise NetrcParseError(
"Macro definition missing null line terminator.",
file, lexer.lineno)
if line == '\n':
# a macro definition finished with consecutive new-line
# characters. The first \n is encountered by the
# readline() method and this is the second \n.
break
self.macros[entryname].append(line)
continue
else:
raise NetrcParseError(
"bad toplevel token %r" % tt, file, lexer.lineno)
if not entryname:
raise NetrcParseError("missing %r name" % tt, file, lexer.lineno)
# We're looking at start of an entry for a named machine or default.
login = account = password = ''
self.hosts[entryname] = {}
while 1:
prev_lineno = lexer.lineno
tt = lexer.get_token()
if tt.startswith('#'):
if lexer.lineno == prev_lineno:
lexer.instream.readline()
continue
if tt in {'', 'machine', 'default', 'macdef'}:
self.hosts[entryname] = (login, account, password)
lexer.push_token(tt)
break
elif tt == 'login' or tt == 'user':
login = lexer.get_token()
elif tt == 'account':
account = lexer.get_token()
elif tt == 'password':
password = lexer.get_token()
else:
raise NetrcParseError("bad follower token %r" % tt,
file, lexer.lineno)
self._security_check(fp, default_netrc, self.hosts[entryname][0])
def _security_check(self, fp, default_netrc, login):
if os.name == 'posix' and default_netrc and login != "anonymous":
prop = os.fstat(fp.fileno())
if prop.st_uid != os.getuid():
import pwd
try:
fowner = pwd.getpwuid(prop.st_uid)[0]
except KeyError:
fowner = 'uid %s' % prop.st_uid
try:
user = pwd.getpwuid(os.getuid())[0]
except KeyError:
user = 'uid %s' % os.getuid()
raise NetrcParseError(
(f"~/.netrc file owner ({fowner}, {user}) does not match"
" current user"))
if (prop.st_mode & (stat.S_IRWXG | stat.S_IRWXO)):
raise NetrcParseError(
"~/.netrc access too permissive: access"
" permissions must restrict access to only"
" the owner")
def authenticators(self, host):
"""Return a (user, account, password) tuple for given host."""
if host in self.hosts:
return self.hosts[host]
elif 'default' in self.hosts:
return self.hosts['default']
else:
return None
def __repr__(self):
"""Dump the class data in the format of a .netrc file."""
rep = ""
for host in self.hosts.keys():
attrs = self.hosts[host]
rep += f"machine {host}\n\tlogin {attrs[0]}\n"
if attrs[1]:
rep += f"\taccount {attrs[1]}\n"
rep += f"\tpassword {attrs[2]}\n"
for macro in self.macros.keys():
rep += f"macdef {macro}\n"
for line in self.macros[macro]:
rep += line
rep += "\n"
return rep
if __name__ == '__main__':
print(netrc())
