from __future__ import with_statement
+import errno as _E
import os as _OS
+from cStringIO import StringIO as _StringIO
import catacomb as _C
-import gdbm as _G
+
+###--------------------------------------------------------------------------
+### Text encoding utilities.
+
+def _literalp(s):
+ """
+ Answer whether S can be represented literally.
+
+ If True, then S can be stored literally, as a metadata item name or
+ value; if False, then S requires some kind of encoding.
+ """
+ return all(ch.isalnum() or ch in '-_:' for ch in s)
+
+def _enc_metaname(name):
+ """Encode NAME as a metadata item name, returning the result."""
+ if _literalp(name):
+ return name
+ else:
+ sio = _StringIO()
+ sio.write('!')
+ for ch in name:
+ if _literalp(ch): sio.write(ch)
+ elif ch == ' ': sio.write('+')
+ else: sio.write('%%%02x' % ord(ch))
+ return sio.getvalue()
+
+def _dec_metaname(name):
+ """Decode NAME as a metadata item name, returning the result."""
+ if not name.startswith('!'):
+ return name
+ else:
+ sio = _StringIO()
+ i, n = 1, len(name)
+ while i < n:
+ ch = name[i]
+ i += 1
+ if ch == '+':
+ sio.write(' ')
+ elif ch == '%':
+ sio.write(chr(int(name[i:i + 2], 16)))
+ i += 2
+ else:
+ sio.write(ch)
+ return sio.getvalue()
+
+def _b64(s):
+ """Encode S as base64, without newlines, and trimming `=' padding."""
+ return s.encode('base64').translate(None, '\n=')
+def _unb64(s):
+ """Decode S as base64 with trimmed `=' padding."""
+ return (s + '='*((4 - len(s))%4)).decode('base64')
+
+def _enc_metaval(val):
+ """Encode VAL as a metadata item value, returning the result."""
+ if _literalp(val): return val
+ else: return '?' + _b64(val)
+
+def _dec_metaval(val):
+ """Decode VAL as a metadata item value, returning the result."""
+ if not val.startswith('?'): return val
+ else: return _unb64(val[1:])
###--------------------------------------------------------------------------
### Underlying cryptography.
database is open for writing.
"""
me._check_write()
- me._del_passwd(label, payload)
+ me._del_passwd(label)
def iter_passwds(me):
"""
me._check_live()
return me._iter_passwds()
-class GDBMStorageBackend (StorageBackend):
+try: import gdbm as _G
+except ImportError: pass
+else:
+ class GDBMStorageBackend (StorageBackend):
+ """
+ My instances store password data in a GDBM database.
+
+ Metadata and password entries are mixed into the same database. The key
+ for a metadata item is simply its name; the key for a password entry is
+ the entry's label prefixed by `$', since we're guaranteed that no
+ metadata item name begins with `$'.
+ """
+
+ NAME = 'gdbm'
+
+ def _open(me, file, writep):
+ try: me._db = _G.open(file, writep and 'w' or 'r')
+ except _G.error, e: raise StorageBackendRefusal, e
+
+ def _create(me, file):
+ me._db = _G.open(file, 'n', 0600)
+
+ def _close(me, abruptp):
+ me._db.close()
+ me._db = None
+
+ def _get_meta(me, name, default):
+ try: return me._db[name]
+ except KeyError: return default
+
+ def _put_meta(me, name, value):
+ me._db[name] = value
+
+ def _del_meta(me, name):
+ del me._db[name]
+
+ def _iter_meta(me):
+ k = me._db.firstkey()
+ while k is not None:
+ if not k.startswith('$'): yield k, me._db[k]
+ k = me._db.nextkey(k)
+
+ def _get_passwd(me, label):
+ return me._db['$' + label]
+
+ def _put_passwd(me, label, payload):
+ me._db['$' + label] = payload
+
+ def _del_passwd(me, label):
+ del me._db['$' + label]
+
+ def _iter_passwds(me):
+ k = me._db.firstkey()
+ while k is not None:
+ if k.startswith('$'): yield k[1:], me._db[k]
+ k = me._db.nextkey(k)
+
+try: import sqlite3 as _Q
+except ImportError: pass
+else:
+ class SQLiteStorageBackend (StorageBackend):
+ """
+ I represent a password database stored in SQLite.
+
+ Metadata and password items are stored in separate tables, so there's no
+ conflict. Some additional metadata is stored in the `meta' table, with
+ names beginning with `$' so as not to conflict with clients:
+
+ $version The schema version of the table.
+ """
+
+ NAME = 'sqlite'
+ VERSION = 0
+
+ def _open(me, file, writep):
+ try:
+ me._db = _Q.connect(file)
+ ver = me._query_scalar(
+ "SELECT value FROM meta WHERE name = '$version'",
+ "version check")
+ except (_Q.DatabaseError, _Q.OperationalError), e:
+ raise StorageBackendRefusal, e
+ if ver is None: raise ValueError, 'database broken (missing $version)'
+ elif ver < me.VERSION: me._upgrade(ver)
+ elif ver > me.VERSION:
+ raise ValueError, 'unknown database schema version (%d > %d)' % \
+ (ver, me.VERSION)
+
+ def _create(me, file):
+ fd = _OS.open(file, _OS.O_WRONLY | _OS.O_CREAT | _OS.O_EXCL, 0600)
+ _OS.close(fd)
+ try:
+ me._db = _Q.connect(file)
+ c = me._db.cursor()
+ c.execute("""
+ CREATE TABLE meta (
+ name TEXT PRIMARY KEY NOT NULL,
+ value BLOB NOT NULL);
+ """)
+ c.execute("""
+ CREATE TABLE passwd (
+ label BLOB PRIMARY KEY NOT NULL,
+ payload BLOB NOT NULL);
+ """)
+ c.execute("""
+ INSERT INTO meta (name, value) VALUES ('$version', ?);
+ """, [me.VERSION])
+ except:
+ try: _OS.unlink(file)
+ except OSError: pass
+ raise
+
+ def _upgrade(me, ver):
+ """Upgrade the database from schema version VER."""
+ assert False, 'how embarrassing'
+
+ def _close(me, abruptp):
+ if not abruptp: me._db.commit()
+ me._db.close()
+ me._db = None
+
+ def _fetch_scalar(me, c, what, default = None):
+ try: row = next(c)
+ except StopIteration: val = default
+ else: val, = row
+ try: row = next(c)
+ except StopIteration: pass
+ else: raise ValueError, 'multiple matching records for %s' % what
+ return val
+
+ def _query_scalar(me, query, what, default = None, args = []):
+ c = me._db.cursor()
+ c.execute(query, args)
+ return me._fetch_scalar(c, what, default)
+
+ def _get_meta(me, name, default):
+ v = me._query_scalar("SELECT value FROM meta WHERE name = ?",
+ "metadata item `%s'" % name,
+ default = default, args = [name])
+ if v is default: return v
+ else: return str(v)
+
+ def _put_meta(me, name, value):
+ c = me._db.cursor()
+ c.execute("INSERT OR REPLACE INTO meta (name, value) VALUES (?, ?)",
+ [name, buffer(value)])
+
+ def _del_meta(me, name):
+ c = me._db.cursor()
+ c.execute("DELETE FROM meta WHERE name = ?", [name])
+ if not c.rowcount: raise KeyError, name
+
+ def _iter_meta(me):
+ c = me._db.cursor()
+ c.execute("SELECT name, value FROM meta WHERE name NOT LIKE '$%'")
+ for k, v in c: yield k, str(v)
+
+ def _get_passwd(me, label):
+ pld = me._query_scalar("SELECT payload FROM passwd WHERE label = ?",
+ "password", default = None,
+ args = [buffer(label)])
+ if pld is None: raise KeyError, label
+ return str(pld)
+
+ def _put_passwd(me, label, payload):
+ c = me._db.cursor()
+ c.execute("INSERT OR REPLACE INTO passwd (label, payload) "
+ "VALUES (?, ?)",
+ [buffer(label), buffer(payload)])
+
+ def _del_passwd(me, label):
+ c = me._db.cursor()
+ c.execute("DELETE FROM passwd WHERE label = ?", [label])
+ if not c.rowcount: raise KeyError, label
+
+ def _iter_passwds(me):
+ c = me._db.cursor()
+ c.execute("SELECT label, payload FROM passwd")
+ for k, v in c: yield str(k), str(v)
+
+class PlainTextBackend (StorageBackend):
"""
- My instances store password data in a GDBM database.
+ I'm a utility base class for storage backends which use plain text files.
- Metadata and password entries are mixed into the same database. The key
- for a metadata item is simply its name; the key for a password entry is
- the entry's label prefixed by `$', since we're guaranteed that no
- metadata item name begins with `$'.
+ I provide subclasses with the following capabilities.
+
+ * Creating files, with given modes, optionally ensuring that the file
+ doesn't exist already.
+
+ * Parsing flat text files, checking leading magic, skipping comments, and
+ providing standard encodings of troublesome characters and binary
+ strings in metadata and password records. See below.
+
+ * Maintenance of metadata and password records in in-memory dictionaries,
+ with ready implementations of the necessary StorageBackend subclass
+ responsibility methods. (Subclasses can override these if they want to
+ make different arrangements.)
+
+ Metadata records are written with an optional prefix string chosen by the
+ caller, followed by a `NAME=VALUE' pair. The NAME is form-urlencoded and
+ prefixed with `!' if it contains strange characters; the VALUE is base64-
+ encoded (without the pointless trailing `=' padding) and prefixed with `?'
+ if necessary.
+
+ Password records are written with an optional prefix string chosen by the
+ caller, followed by a LABEL=PAYLOAD pair, both of which are base64-encoded
+ (without padding).
+
+ The following attributes are available for subclasses:
+
+ _meta Dictionary mapping metadata item names to their values.
+ Populated by `_parse_meta' and managed by `_get_meta' and
+ friends.
+
+ _pw Dictionary mapping password labels to encrypted payloads.
+ Populated by `_parse_passwd' and managed by `_get_passwd' and
+ friends.
+
+ _dirtyp Boolean: set if either of the dictionaries has been modified.
"""
- NAME = 'gdbm'
+ def __init__(me, *args, **kw):
+ """
+ Hook for initialization.
+
+ Sets up the published instance attributes.
+ """
+ me._meta = {}
+ me._pw = {}
+ me._dirtyp = False
+ super(PlainTextBackend, me).__init__(*args, **kw)
+
+ def _create_file(me, file, mode = 0600, freshp = False):
+ """
+ Make sure FILE exists, creating it with the given MODE if necessary.
+
+ If FRESHP is true, then make sure the file did not exist previously.
+ Return a file object for the newly created file.
+ """
+ flags = _OS.O_CREAT | _OS.O_WRONLY
+ if freshp: flags |= _OS.O_EXCL
+ else: flags |= _OS.O_TRUNC
+ fd = _OS.open(file, flags, mode)
+ return _OS.fdopen(fd, 'w')
+
+ def _mark_dirty(me):
+ """
+ Set the `_dirtyp' flag.
+
+ Subclasses might find it useful to intercept this method.
+ """
+ me._dirtyp = True
+
+ def _eqsplit(me, line):
+ """
+ Extract the KEY, VALUE pair from a LINE of the form `KEY=VALUE'.
+
+ Raise `ValueError' if there is no `=' in the LINE.
+ """
+ eq = line.index('=')
+ return line[:eq], line[eq + 1:]
+
+ def _parse_file(me, file, magic = None):
+ """
+ Parse a FILE.
+
+ Specifically:
+
+ * Raise `StorageBackendRefusal' if that the first line doesn't match
+ MAGIC (if provided). MAGIC should not contain the terminating
+ newline.
+
+ * Ignore comments (beginning `#') and blank lines.
+
+ * Call `_parse_line' (provided by the subclass) for other lines.
+ """
+ with open(file, 'r') as f:
+ if magic is not None:
+ if f.readline().rstrip('\n') != magic: raise StorageBackendRefusal
+ for line in f:
+ line = line.rstrip('\n')
+ if not line or line.startswith('#'): continue
+ me._parse_line(line)
+
+ def _write_file(me, file, writebody, mode = 0600, magic = None):
+ """
+ Update FILE atomically.
+
+ The newly created file will have the given MODE. If MAGIC is given, then
+ write that as the first line. Calls WRITEBODY(F) to write the main body
+ of the file where F is a file object for the new file.
+ """
+ new = file + '.new'
+ with me._create_file(new, mode) as f:
+ if magic is not None: f.write(magic + '\n')
+ writebody(f)
+ _OS.rename(new, file)
+
+ def _parse_meta(me, line):
+ """Parse LINE as a metadata NAME=VALUE pair, and updates `_meta'."""
+ k, v = me._eqsplit(line)
+ me._meta[_dec_metaname(k)] = _dec_metaval(v)
+
+ def _write_meta(me, f, prefix = ''):
+ """Write the metadata records to F, each with the given PREFIX."""
+ f.write('\n## Metadata.\n')
+ for k, v in me._meta.iteritems():
+ f.write('%s%s=%s\n' % (prefix, _enc_metaname(k), _enc_metaval(v)))
+
+ def _get_meta(me, name, default):
+ return me._meta.get(name, default)
+ def _put_meta(me, name, value):
+ me._mark_dirty()
+ me._meta[name] = value
+ def _del_meta(me, name):
+ me._mark_dirty()
+ del me._meta[name]
+ def _iter_meta(me):
+ return me._meta.iteritems()
+
+ def _parse_passwd(me, line):
+ """Parse LINE as a password LABEL=PAYLOAD pair, and updates `_pw'."""
+ k, v = me._eqsplit(line)
+ me._pw[_unb64(k)] = _unb64(v)
+
+ def _write_passwd(me, f, prefix = ''):
+ """Write the password records to F, each with the given PREFIX."""
+ f.write('\n## Password data.\n')
+ for k, v in me._pw.iteritems():
+ f.write('%s%s=%s\n' % (prefix, _b64(k), _b64(v)))
+
+ def _get_passwd(me, label):
+ return me._pw[str(label)]
+ def _put_passwd(me, label, payload):
+ me._mark_dirty()
+ me._pw[str(label)] = payload
+ def _del_passwd(me, label):
+ me._mark_dirty()
+ del me._pw[str(label)]
+ def _iter_passwds(me):
+ return me._pw.iteritems()
+
+class FlatFileStorageBackend (PlainTextBackend):
+ """
+ I maintain a password database in a plain text file.
+
+ The text file consists of lines, as follows.
+
+ * Empty lines, and lines beginning with `#' (in the leftmost column only)
+ are ignored.
+
+ * Lines of the form `$LABEL=PAYLOAD' store password data. Both LABEL and
+ PAYLOAD are base64-encoded, without `=' padding.
+
+ * Lines of the form `NAME=VALUE' store metadata. If the NAME contains
+ characters other than alphanumerics, hyphens, underscores, and colons,
+ then it is form-urlencoded, and prefixed wth `!'. If the VALUE
+ contains such characters, then it is base64-encoded, without `='
+ padding, and prefixed with `?'.
+
+ * Other lines are erroneous.
+
+ The file is rewritten from scratch when it's changed: any existing
+ commentary is lost, and items may be reordered. There is no file locking,
+ but the file is updated atomically, by renaming.
+
+ It is expected that the FlatFileStorageBackend is used mostly for
+ diagnostics and transfer, rather than for a live system.
+ """
+
+ NAME = 'flat'
+ PRIO = 0
+ MAGIC = '### pwsafe password database'
def _open(me, file, writep):
- try: me._db = _G.open(file, writep and 'w' or 'r')
- except _G.error, e: raise StorageBackendRefusal, e
+ if not _OS.path.isfile(file): raise StorageBackendRefusal
+ me._parse_file(file, magic = me.MAGIC)
+ def _parse_line(me, line):
+ if line.startswith('$'): me._parse_passwd(line[1:])
+ else: me._parse_meta(line)
def _create(me, file):
- me._db = _G.open(file, 'n', 0600)
+ with me._create_file(file, freshp = True) as f: pass
+ me._file = file
+ me._mark_dirty()
def _close(me, abruptp):
- me._db.close()
- me._db = None
+ if not abruptp and me._dirtyp:
+ me._write_file(me._file, me._write_body, magic = me.MAGIC)
- def _get_meta(me, name, default):
- try: return me._db[name]
- except KeyError: return default
+ def _write_body(me, f):
+ me._write_meta(f)
+ me._write_passwd(f, '$')
- def _put_meta(me, name, value):
- me._db[name] = value
+class DirectoryStorageBackend (PlainTextBackend):
+ """
+ I maintain a password database in a directory, with one file per password.
- def _del_meta(me, name):
- del me._db[name]
+ This makes password databases easy to maintain in a revision-control system
+ such as Git.
- def _iter_meta(me):
- k = me._db.firstkey()
- while k is not None:
- if not k.startswith('$'): yield k, me._db[k]
- k = me._db.nextkey(k)
+ The directory is structured as follows.
- def _get_passwd(me, label):
- return me._db['$' + label]
+ dir/meta Contains metadata, similar to the `FlatFileBackend'.
- def _put_passwd(me, label, payload):
- me._db['$' + label] = payload
+ dir/pw/LABEL Contains the (raw binary) payload for the given password
+ LABEL (base64-encoded, without the useless `=' padding, and
+ with `/' replaced by `.').
- def _del_passwd(me, label):
- del me._db['$' + label]
+ dir/tmp/ Contains temporary files used by the implementation.
+ """
+
+ NAME = 'dir'
+ METAMAGIC = '### pwsafe password directory metadata'
+
+ def _open(me, file, writep):
+ if not _OS.path.isdir(file) or \
+ not _OS.path.isdir(_OS.path.join(file, 'pw')) or \
+ not _OS.path.isdir(_OS.path.join(file, 'tmp')) or \
+ not _OS.path.isfile(_OS.path.join(file, 'meta')):
+ raise StorageBackendRefusal
+ me._dir = file
+ me._parse_file(_OS.path.join(file, 'meta'), magic = me.METAMAGIC)
+ def _parse_line(me, line):
+ me._parse_meta(line)
+ def _create(me, file):
+ _OS.mkdir(file, 0700)
+ _OS.mkdir(_OS.path.join(file, 'pw'), 0700)
+ _OS.mkdir(_OS.path.join(file, 'tmp'), 0700)
+ me._mark_dirty()
+ me._dir = file
+
+ def _close(me, abruptp):
+ if not abruptp and me._dirtyp:
+ me._write_file(_OS.path.join(me._dir, 'meta'),
+ me._write_meta, magic = me.METAMAGIC)
+
+ def _pwfile(me, label, dir = 'pw'):
+ return _OS.path.join(me._dir, dir, _b64(label).replace('/', '.'))
+ def _get_passwd(me, label):
+ try:
+ f = open(me._pwfile(label), 'rb')
+ except (OSError, IOError), e:
+ if e.errno == _E.ENOENT: raise KeyError, label
+ else: raise
+ with f: return f.read()
+ def _put_passwd(me, label, payload):
+ new = me._pwfile(label, 'tmp')
+ fd = _OS.open(new, _OS.O_WRONLY | _OS.O_CREAT | _OS.O_TRUNC, 0600)
+ _OS.close(fd)
+ with open(new, 'wb') as f: f.write(payload)
+ _OS.rename(new, me._pwfile(label))
+ def _del_passwd(me, label):
+ try:
+ _OS.remove(me._pwfile(label))
+ except (OSError, IOError), e:
+ if e == _E.ENOENT: raise KeyError, label
+ else: raise
def _iter_passwds(me):
- k = me._db.firstkey()
- while k is not None:
- if k.startswith('$'): yield k[1:], me._db[k]
- k = me._db.nextkey(k)
+ pw = _OS.path.join(me._dir, 'pw')
+ for i in _OS.listdir(pw):
+ with open(_OS.path.join(pw, i), 'rb') as f: pld = f.read()
+ yield _unb64(i.replace('.', '/')), pld
###--------------------------------------------------------------------------
### Password storage.
~mdw / catacomb-python / blobdiff