expose the private-key feature in the `tahoe put` cli

src/allmydata/scripts/cli.py

@@ -181,8 +181,19 @@ class PutOptions(FileStoreOptions):
     optFlags = [
         ("mutable", "m", "Create a mutable file instead of an immutable one (like --format=SDMF)"),
     ]
+
     optParameters = [
         ("format", None, None, "Create a file with the given format: SDMF and MDMF for mutable, CHK (default) for immutable. (case-insensitive)"),
+
+        ("private-key-path", None, None,
+         "***Warning*** "
+         "It is possible to use this option to spoil the normal security properties of mutable objects. "
+         "It is also possible to corrupt or destroy data with this option. "
+         "For mutables only, "
+         "this gives a file containing a PEM-encoded 2048 bit RSA private key to use as the signature key for the mutable. "
+         "The private key must be handled at least as strictly as the resulting capability string. "
+         "A single private key must not be used for more than one mutable."
+         ),
     ]
 
     def parseArgs(self, arg1=None, arg2=None):

src/allmydata/scripts/tahoe_put.py

@@ -1,23 +1,31 @@
 """
-Ported to Python 3.
+Implement the ``tahoe put`` command.
 """
-from __future__ import unicode_literals
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-from future.utils import PY2
-if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+from __future__ import annotations
 
 from io import BytesIO
 from urllib.parse import quote as url_quote
+from base64 import urlsafe_b64encode
 
+from cryptography.hazmat.primitives.serialization import load_pem_private_key
+
+from twisted.python.filepath import FilePath
+
+from allmydata.crypto.rsa import der_string_from_signing_key
 from allmydata.scripts.common_http import do_http, format_http_success, format_http_error
 from allmydata.scripts.common import get_alias, DEFAULT_ALIAS, escape_path, \
                                      UnknownAliasError
 from allmydata.util.encodingutil import quote_output
 
+def load_private_key(path: str) -> str:
+    """
+    Load a private key from a file and return it in a format appropriate
+    to include in the HTTP request.
+    """
+    privkey = load_pem_private_key(FilePath(path).getContent(), password=None)
+    derbytes = der_string_from_signing_key(privkey)
+    return urlsafe_b64encode(derbytes).decode("ascii")
+
 def put(options):
     """
     @param verbosity: 0, 1, or 2, meaning quiet, verbose, or very verbose
@@ -29,6 +37,10 @@ def put(options):
     from_file = options.from_file
     to_file = options.to_file
     mutable = options['mutable']
+    if options["private-key-path"] is None:
+        private_key = None
+    else:
+        private_key = load_private_key(options["private-key-path"])
     format = options['format']
     if options['quiet']:
         verbosity = 0
@@ -79,6 +91,12 @@ def put(options):
     queryargs = []
     if mutable:
         queryargs.append("mutable=true")
+        if private_key is not None:
+            queryargs.append(f"private-key={private_key}")
+    else:
+        if private_key is not None:
+            raise Exception("Can only supply a private key for mutables.")
+
     if format:
         queryargs.append("format=%s" % format)
     if queryargs:
@@ -92,9 +110,6 @@ def put(options):
         if verbosity > 0:
             print("waiting for file data on stdin..", file=stderr)
         # We're uploading arbitrary files, so this had better be bytes:
-        if PY2:
-            stdinb = stdin
-        else:
         stdinb = stdin.buffer
         data = stdinb.read()
         infileobj = BytesIO(data)

src/allmydata/test/cli/test_put.py

@@ -1,19 +1,17 @@
 """
-Ported to Python 3.
+Tests for the ``tahoe put`` CLI tool.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-
-from future.utils import PY2
-if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+from __future__ import annotations
 
+from typing import Callable, Awaitable, TypeVar
 import os.path
 from twisted.trial import unittest
 from twisted.python import usage
+from twisted.python.filepath import FilePath
 
+from cryptography.hazmat.primitives.serialization import load_pem_private_key
+
+from allmydata.uri import from_string
 from allmydata.util import fileutil
 from allmydata.scripts.common import get_aliases
 from allmydata.scripts import cli
@@ -22,6 +20,9 @@ from ..common_util import skip_if_cannot_represent_filename
 from allmydata.util.encodingutil import get_io_encoding
 from allmydata.util.fileutil import abspath_expanduser_unicode
 from .common import CLITestMixin
+from allmydata.mutable.common import derive_mutable_keys
+
+T = TypeVar("T")
 
 class Put(GridTestMixin, CLITestMixin, unittest.TestCase):
 
@@ -215,6 +216,59 @@ class Put(GridTestMixin, CLITestMixin, unittest.TestCase):
 
         return d
 
+    async def test_unlinked_mutable_specified_private_key(self) -> None:
+        """
+        A new unlinked mutable can be created using a specified private
+        key.
+        """
+        self.basedir = "cli/Put/unlinked-mutable-with-key"
+        await self._test_mutable_specified_key(
+            lambda do_cli, pempath, datapath: do_cli(
+                "put", "--mutable", "--private-key-path", pempath.path,
+                stdin=datapath.getContent(),
+            ),
+        )
+
+    async def test_linked_mutable_specified_private_key(self) -> None:
+        """
+        A new linked mutable can be created using a specified private key.
+        """
+        self.basedir = "cli/Put/linked-mutable-with-key"
+        await self._test_mutable_specified_key(
+            lambda do_cli, pempath, datapath: do_cli(
+                "put", "--mutable", "--private-key-path", pempath.path, datapath.path,
+            ),
+        )
+
+    async def _test_mutable_specified_key(
+            self,
+            run: Callable[[Callable[..., T], FilePath, FilePath], Awaitable[T]],
+    ) -> None:
+        """
+        A helper for testing mutable creation.
+
+        :param run: A function to do the creation.  It is called with
+            ``self.do_cli`` and the path to a private key PEM file and a data
+            file.  It returns whatever ``do_cli`` returns.
+        """
+        self.set_up_grid(oneshare=True)
+
+        pempath = FilePath(__file__).parent().sibling("data").child("openssl-rsa-2048.txt")
+        datapath = FilePath(self.basedir).child("data")
+        datapath.setContent(b"Hello world" * 1024)
+
+        (rc, out, err) = await run(self.do_cli, pempath, datapath)
+        self.assertEqual(rc, 0, (out, err))
+        cap = from_string(out.strip())
+        # The capability is derived from the key we specified.
+        privkey = load_pem_private_key(pempath.getContent(), password=None)
+        pubkey = privkey.public_key()
+        writekey, _, fingerprint = derive_mutable_keys((pubkey, privkey))
+        self.assertEqual(
+            (writekey, fingerprint),
+            (cap.writekey, cap.fingerprint),
+        )
+
     def test_mutable(self):
         # echo DATA1 | tahoe put --mutable - uploaded.txt
         # echo DATA2 | tahoe put - uploaded.txt # should modify-in-place

src/allmydata/web/filenode.py

@@ -4,7 +4,6 @@ Ported to Python 3.
 from __future__ import annotations
 
 from twisted.web import http, static
-from twisted.web.iweb import IRequest
 from twisted.internet import defer
 from twisted.web.resource import (
     Resource,

src/allmydata/web/unlinked.py

@@ -1,14 +1,7 @@
 """
 Ported to Python 3.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-
-from future.utils import PY2
-if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+from __future__ import annotations
 
 from urllib.parse import quote as urlquote
 
@@ -25,6 +18,7 @@ from twisted.web.template import (
 from allmydata.immutable.upload import FileHandle
 from allmydata.mutable.publish import MutableFileHandle
 from allmydata.web.common import (
+    get_keypair,
     get_arg,
     boolean_of_arg,
     convert_children_json,
@@ -48,7 +42,8 @@ def PUTUnlinkedSSK(req, client, version):
     # SDMF: files are small, and we can only upload data
     req.content.seek(0)
     data = MutableFileHandle(req.content)
-    d = client.create_mutable_file(data, version=version)
+    keypair = get_keypair(req)
+    d = client.create_mutable_file(data, version=version, unique_keypair=keypair)
     d.addCallback(lambda n: n.get_uri())
     return d