"""An object-oriented interface to .netrc files.""" # Module and documentation by Eric S. Raymond, 21 Dec 1998 import os, stat __all__ = ["netrc", "NetrcParseError"] def _can_security_check(): # On WASI, getuid() is indicated as a stub but it may also be missing. return os.name == 'posix' and hasattr(os, 'getuid') def _getpwuid(uid): try: import pwd return pwd.getpwuid(uid)[0] except (ImportError, LookupError): return f'uid {uid}' 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 _can_security_check() and default_netrc and login != "anonymous": prop = os.fstat(fp.fileno()) current_user_id = os.getuid() if prop.st_uid != current_user_id: fowner = _getpwuid(prop.st_uid) user = _getpwuid(current_user_id) 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())