all: Finalise python3 support.

Basically, wrap stdout and stderr whenever they do not have an encoding
with an ascii-encoding writer, and write unicode to stdout & stderr.
wsgi.errors is defined in the reference implementation as being a StringIO,
so follow that.
Stop using argparse.FileType to get rid of python3 "file not closed"
errors.
Also, fix setup access to CHANGES.txt .
Also, fix 2to3 involvement.
Also, replace test.captureStdout with extra tool arguments.

caucase/cli.py

@@ -51,7 +51,7 @@ class RetryingCaucaseClient(CaucaseClient):
   Retries every 10 seconds.
   """
   _until = staticmethod(utils.until)
-  _log_file = sys.stdout
+  _log_file = utils.toUnicodeWritableStream(sys.stdout)
 
   def _request(self, connection, method, url, body=None, headers=None):
     while True:
@@ -79,10 +79,10 @@ class RetryingCaucaseClient(CaucaseClient):
         # letting non-printable characters through.
         next_try = datetime.datetime.utcnow() + datetime.timedelta(0, 10)
         print(
-          'Got a network error, retrying at %s, %s: %r' % (
-            next_try.strftime(b'%Y-%m-%d %H:%M:%S +0000'),
+          u'Got a network error, retrying at %s, %s: %r' % (
+            next_try.strftime(u'%Y-%m-%d %H:%M:%S +0000'),
             exception.__class__.__name__,
-            str(exception),
+            unicode(exception),
           ),
           file=self._log_file,
         )
@@ -104,8 +104,14 @@ class CLICaucaseClient(object):
   # Note: this class it more to reduce local variable scopes (avoiding
   # accidental mixups) in each methods than about API declaration.
 
-  def __init__(self, client):
+  def __init__(self, client, stdout, stderr):
     self._client = client
+    self._stdout = stdout
+    self._stderr = stderr
+
+  def _print(self, *args, **kw):
+    kw.setdefault('file', self._stdout)
+    print(*args, **kw)
 
   def putCSR(self, csr_path_list):
     """
@@ -115,9 +121,9 @@ class CLICaucaseClient(object):
       csr_pem = utils.getCertRequest(csr_path)
       # Quick sanity check
       utils.load_certificate_request(csr_pem)
-      print(
+      self._print(
         self._client.createCertificateSigningRequest(csr_pem),
-        utils.toBytes(csr_path),
+        csr_path,
       )
 
   def getCSR(self, csr_id_path_list):
@@ -145,41 +151,41 @@ class CLICaucaseClient(object):
         except CaucaseError as e:
           if e.args[0] != httplib.NOT_FOUND:
             raise
-          print(crt_id, b'not found - maybe CSR was rejected ?')
+          self._print(crt_id, 'not found - maybe CSR was rejected ?')
           error = True
         else:
-          print(crt_id, b'CSR still pending')
+          self._print(crt_id, 'CSR still pending')
           warning = True
       else:
-        print(crt_id, end=' ')
+        self._print(crt_id, end=' ')
         if utils.isCertificateAutoSigned(utils.load_certificate(
           crt_pem,
           ca_list,
           None,
         )):
-          print(b'was (originally) automatically approved')
+          self._print('was (originally) automatically approved')
         else:
-          print(b'was (originally) manually approved')
+          self._print('was (originally) manually approved')
         if os.path.exists(crt_path):
           try:
             key_pem = utils.getKey(crt_path)
           except ValueError:
-            print(
-              b'Expected to find exactly one privatekey key in %s, skipping' % (
+            self._print(
+              'Expected to find exactly one privatekey key in %s, skipping' % (
                 crt_path,
               ),
-              file=sys.stderr,
+              file=self._stderr,
             )
             error = True
             continue
           try:
             utils.validateCertAndKey(crt_pem, key_pem)
           except ValueError:
-            print(
-              b'Key in %s does not match retrieved certificate, skipping' % (
+            self._print(
+              'Key in %s does not match retrieved certificate, skipping' % (
                 crt_path,
               ),
-              file=sys.stderr,
+              file=self._stderr,
             )
             error = True
             continue
@@ -195,11 +201,11 @@ class CLICaucaseClient(object):
       try:
         crt, key, _ = utils.getKeyPair(crt_path, key_path)
       except ValueError:
-        print(
-          b'Could not find (exactly) one matching key pair in %s, skipping' % (
+        self._print(
+          'Could not find (exactly) one matching key pair in %s, skipping' % (
             [x for x in set((crt_path, key_path)) if x],
           ),
-          file=sys.stderr,
+          file=self._stderr,
         )
         error = True
         continue
@@ -225,11 +231,11 @@ class CLICaucaseClient(object):
           key_path,
         )
       except ValueError:
-        print(
-          b'Could not find (exactly) one matching key pair in %s, skipping' % (
+        self._print(
+          'Could not find (exactly) one matching key pair in %s, skipping' % (
             [x for x in set((crt_path, key_path)) if x],
           ),
-          file=sys.stderr,
+          file=self._stderr,
         )
         error = True
         continue
@@ -240,13 +246,13 @@ class CLICaucaseClient(object):
           None,
         )
       except exceptions.CertificateVerificationError:
-        print(
+        self._print(
           crt_path,
-          b'was not signed by this CA, revoked or otherwise invalid, skipping',
+          'was not signed by this CA, revoked or otherwise invalid, skipping',
         )
         continue
       if renewal_deadline < old_crt.not_valid_after:
-        print(crt_path, b'did not reach renew threshold, not renewing')
+        self._print(crt_path, 'did not reach renew threshold, not renewing')
         continue
       new_key_pem, new_crt_pem = self._client.renewCertificate(
         old_crt=old_crt,
@@ -274,22 +280,22 @@ class CLICaucaseClient(object):
     """
     --list-csr
     """
-    print(b'-- pending', mode, b'CSRs --')
-    print(
-      b'%20s | %s' % (
-        b'csr_id',
-        b'subject preview (fetch csr and check full content !)',
+    self._print('-- pending', mode, 'CSRs --')
+    self._print(
+      '%20s | %s' % (
+        'csr_id',
+        'subject preview (fetch csr and check full content !)',
       ),
     )
     for entry in self._client.getPendingCertificateRequestList():
       csr = utils.load_certificate_request(utils.toBytes(entry['csr']))
-      print(
-        b'%20s | %r' % (
-          utils.toBytes(entry['id']),
-          utils.toBytes(repr(csr.subject)),
+      self._print(
+        '%20s | %r' % (
+          entry['id'],
+          repr(csr.subject),
         ),
       )
-    print(b'-- end of pending', mode, b'CSRs --')
+    self._print('-- end of pending', mode, 'CSRs --')
 
   def signCSR(self, csr_id_list):
     """
@@ -332,11 +338,11 @@ class CLICaucaseClient(object):
         # authenticated revocations).
         crt_pem = utils.getCert(crt_path)
       except ValueError:
-        print(
-          b'Could not load a single certificate in %s, skipping' % (
+        self._print(
+          'Could not load a single certificate in %s, skipping' % (
             crt_path,
           ),
-          file=sys.stderr,
+          file=self._stderr,
         )
       self._client.revokeCertificate(crt_pem)
     return error
@@ -348,7 +354,7 @@ class CLICaucaseClient(object):
     for serial in serial_list:
       self._client.revokeSerial(serial)
 
-def main(argv=None):
+def main(argv=None, stdout=sys.stdout, stderr=sys.stderr):
   """
   Command line caucase client entry point.
   """
@@ -547,6 +553,8 @@ def main(argv=None):
     'Use --revoke and --revoke-other-crt whenever possible.',
   )
   args = parser.parse_args(argv)
+  stdout = utils.toUnicodeWritableStream(stdout)
+  stderr = utils.toUnicodeWritableStream(stderr)
 
   sign_csr_id_set = set(args.sign_csr)
   sign_with_csr_id_set = {x for x, _ in args.sign_csr_with}
@@ -556,9 +564,9 @@ def main(argv=None):
     sign_csr_id_set.intersection(sign_with_csr_id_set)
   ):
     print(
-      b'A given CSR_ID cannot be in more than one of --sign-csr, '
-      b'--sign-csr-with and --reject-csr',
-      file=sys.stderr,
+      'A given CSR_ID cannot be in more than one of --sign-csr, '
+      '--sign-csr-with and --reject-csr',
+      file=stderr,
     )
     raise SystemExit(STATUS_ERROR)
 
@@ -585,6 +593,8 @@ def main(argv=None):
         ca_crt_pem_list=utils.getCertList(args.ca_crt),
         user_key=args.user_key,
       ),
+      stdout=stdout,
+      stderr=stderr,
     )
     ca_list = [
       utils.load_ca_certificate(x)
@@ -802,12 +812,12 @@ def updater(argv=None, until=utils.until):
       ca_crt_pem_list=utils.getCertList(args.cas_ca)
     )
     if args.crt and not utils.hasOneCert(args.crt):
-      print(b'Bootstraping...')
+      print('Bootstraping...')
       csr_pem = utils.getCertRequest(args.csr)
       # Quick sanity check before bothering server
       utils.load_certificate_request(csr_pem)
       csr_id = client.createCertificateSigningRequest(csr_pem)
-      print(b'Waiting for signature of', csr_id)
+      print('Waiting for signature of', csr_id)
       while True:
         try:
           crt_pem = client.getCertificate(csr_id)
@@ -825,12 +835,12 @@ def updater(argv=None, until=utils.until):
             crt_file.write(crt_pem)
           updated = True
           break
-      print(b'Bootstrap done')
+      print('Bootstrap done')
     next_deadline = datetime.datetime.utcnow()
     while True:
       print(
-        b'Next wake-up at',
-        next_deadline.strftime(b'%Y-%m-%d %H:%M:%S +0000'),
+        'Next wake-up at',
+        next_deadline.strftime('%Y-%m-%d %H:%M:%S +0000'),
       )
       now = until(next_deadline)
       next_deadline = now + max_sleep
@@ -843,7 +853,7 @@ def updater(argv=None, until=utils.until):
           ca_crt_pem_list=utils.getCertList(args.cas_ca)
         )
       if RetryingCaucaseClient.updateCAFile(ca_url, args.ca):
-        print(b'Got new CA')
+        print('Got new CA')
         updated = True
         # Note: CRL expiration should happen several time during CA renewal
         # period, so it should not be needed to keep track of CA expiration
@@ -853,7 +863,7 @@ def updater(argv=None, until=utils.until):
         for x in utils.getCertList(args.ca)
       ]
       if RetryingCaucaseClient.updateCRLFile(ca_url, args.crl, ca_crt_list):
-        print(b'Got new CRL')
+        print('Got new CRL')
         updated = True
       with open(args.crl, 'rb') as crl_file:
         next_deadline = min(
@@ -867,7 +877,7 @@ def updater(argv=None, until=utils.until):
         crt_pem, key_pem, key_path = utils.getKeyPair(args.crt, args.key)
         crt = utils.load_certificate(crt_pem, ca_crt_list, None)
         if crt.not_valid_after - threshold <= now:
-          print(b'Renewing', args.crt)
+          print('Renewing', args.crt)
           new_key_pem, new_crt_pem = client.renewCertificate(
             old_crt=crt,
             old_key=utils.load_privatekey(key_pem),
@@ -901,7 +911,7 @@ def updater(argv=None, until=utils.until):
         if args.on_renew is not None:
           status = os.system(args.on_renew)
           if status:
-            print(b'Renewal hook exited with status:', status, file=sys.stderr)
+            print('Renewal hook exited with status:', status, file=sys.stderr)
             raise SystemExit(STATUS_ERROR)
         updated = False
   except (utils.SleepInterrupt, SystemExit):
@@ -972,7 +982,7 @@ def rerequest(argv=None):
   with open(args.csr, 'wb') as csr_file:
     csr_file.write(csr_pem)
 
-def key_id(argv=None):
+def key_id(argv=None, stdout=sys.stdout):
   """
   Displays key identifier from private key, and the list of acceptable key
   identifiers for a given backup file.
@@ -1001,6 +1011,7 @@ def key_id(argv=None):
     'identifiers of.',
   )
   args = parser.parse_args(argv)
+  stdout = utils.toUnicodeWritableStream(stdout)
   for key_path in args.private_key:
     with open(key_path, 'rb') as key_file:
       print(
@@ -1010,9 +1021,10 @@ def key_id(argv=None):
             utils.load_privatekey(key_file.read()).public_key(),
           ).digest,
         ),
+        file=stdout,
       )
   for backup_path in args.backup:
-    print(backup_path)
+    print(backup_path, file=stdout)
     with open(backup_path, 'rb') as backup_file:
       magic = backup_file.read(8)
       if magic != b'caucase\0':
@@ -1022,4 +1034,4 @@ def key_id(argv=None):
         backup_file.read(struct.calcsize('<I')),
       )
       for key_entry in json.loads(backup_file.read(header_len))['key_list']:
-        print(b' ', key_entry['id'].encode('utf-8'))
+        print(' ', key_entry['id'].encode('utf-8'), file=stdout)

caucase/http.py

@@ -173,8 +173,12 @@ class CaucaseWSGIRequestHandler(WSGIRequestHandler):
   remote_user_name = '-'
 
   def __init__(self, *args, **kw):
-    self._log_file = kw.pop('log_file', sys.stdout)
-    self._error_file = kw.pop('error_file', sys.stderr)
+    self._log_file = utils.toUnicodeWritableStream(
+      kw.pop('log_file', sys.stdout),
+    )
+    self._error_file = utils.toUnicodeWritableStream(
+      kw.pop('error_file', sys.stderr),
+    )
     WSGIRequestHandler.__init__(self, *args, **kw)
 
   def log_date_time_string(self):
@@ -580,8 +584,10 @@ def main(
     help='Number of days between backups. default: %(default)s',
   )
   args = parser.parse_args(argv)
+  log_file = utils.toUnicodeWritableStream(log_file)
+  error_file = utils.toUnicodeWritableStream(error_file)
 
-  base_url = u'http://' + utils.toUnicode(args.netloc)
+  base_url = 'http://' + utils.toUnicode(args.netloc)
   parsed_base_url = urlparse(base_url)
   hostname = parsed_base_url.hostname
   name_constraints_permited = []
@@ -881,7 +887,7 @@ def main(
       server.server_close()
       server.shutdown()
 
-def manage(argv=None):
+def manage(argv=None, stdout=sys.stdout):
   """
   caucased database management tool.
   """
@@ -922,7 +928,6 @@ def manage(argv=None):
     default=[],
     metavar='PEM_FILE',
     action='append',
-    type=argparse.FileType('rb'),
     help='Import key pairs as initial service CA certificate. '
     'May be provided multiple times to import multiple key pairs. '
     'Keys and certificates may be in separate files. '
@@ -948,7 +953,6 @@ def manage(argv=None):
     default=[],
     metavar='PEM_FILE',
     action='append',
-    type=argparse.FileType('rb'),
     help='Import service revocation list. Corresponding CA certificate must '
     'be already present in the database (including added in the same run '
     'using --import-ca).',
@@ -956,11 +960,11 @@ def manage(argv=None):
   parser.add_argument(
     '--export-ca',
     metavar='PEM_FILE',
-    type=argparse.FileType('wb'),
     help='Export all CA certificates in a PEM file. Passphrase will be '
     'prompted to protect all keys.',
   )
   args = parser.parse_args(argv)
+  stdout = utils.toUnicodeWritableStream(stdout)
   db_path = args.db
   if args.restore_backup:
     (
@@ -1008,9 +1012,11 @@ def manage(argv=None):
     import_ca_dict = defaultdict(
       (lambda: {'crt': None, 'key': None, 'from': []}),
     )
-    for ca_file in args.import_ca:
-      for index, component in enumerate(pem.parse(ca_file.read())):
-        name = '%r, block %i' % (ca_file.name, index)
+    for import_ca in args.import_ca:
+      with open(import_ca, 'rb') as ca_file:
+        ca_data = ca_file.read()
+      for index, component in enumerate(pem.parse(ca_data)):
+        name = '%r, block %i' % (import_ca, index)
         if isinstance(component, pem.Certificate):
           component_name = 'crt'
           component_value = x509.load_pem_x509_certificate(
@@ -1053,11 +1059,16 @@ def manage(argv=None):
       found_from = ', '.join(ca_pair['from'])
       crt = ca_pair['crt']
       if crt is None:
-        print(b'No certificate correspond to', found_from, b'- skipping')
+        print(
+          'No certificate correspond to',
+          found_from,
+          '- skipping',
+          file=stdout,
+        )
         continue
       expiration = utils.datetime2timestamp(crt.not_valid_after)
       if expiration < now:
-        print(b'Skipping expired certificate from', found_from)
+        print('Skipping expired certificate from', found_from, file=stdout)
         del import_ca_dict[identifier]
         continue
       if not args.import_bad_ca:
@@ -1076,11 +1087,16 @@ def manage(argv=None):
             or not key_usage.key_cert_sign or not key_usage.crl_sign
           )
         if failed:
-          print(b'Skipping non-CA certificate from', found_from)
+          print('Skipping non-CA certificate from', found_from, file=stdout)
           continue
       key = ca_pair['key']
       if key is None:
-        print(b'No private key correspond to', found_from, b'- skipping')
+        print(
+          'No private key correspond to',
+          found_from,
+          '- skipping',
+          file=stdout,
+        )
         continue
       imported += 1
       cas_db.appendCAKeyPair(
@@ -1092,7 +1108,7 @@ def manage(argv=None):
       )
     if not imported:
       raise ValueError('No CA certificate imported')
-    print(b'Imported %i CA certificates' % imported)
+    print('Imported %i CA certificates' % imported, file=stdout)
   if args.import_crl:
     db = SQLite3Storage(db_path, table_prefix='cas')
     trusted_ca_crt_set = [
@@ -1104,8 +1120,10 @@ def manage(argv=None):
       for x in trusted_ca_crt_set
     )
     already_revoked_count = revoked_count = 0
-    for crl_file in args.import_crl:
-      for revoked in utils.load_crl(crl_file.read(), trusted_ca_crt_set):
+    for import_crl in args.import_crl:
+      with open(import_crl, 'rb') as crl_file:
+        crl_data = crl_file.read()
+      for revoked in utils.load_crl(crl_data, trusted_ca_crt_set):
         try:
           db.revoke(
             revoked.serial_number,
@@ -1115,15 +1133,19 @@ def manage(argv=None):
           already_revoked_count += 1
         else:
           revoked_count += 1
-    print(b'Revoked %i certificates (%i were already revoked)' % (
+    print(
+      'Revoked %i certificates (%i were already revoked)' % (
         revoked_count,
         already_revoked_count,
-    ))
+      ),
+      file=stdout,
+    )
   if args.export_ca is not None:
     encryption_algorithm = serialization.BestAvailableEncryption(
       getBytePass('CA export passphrase: ')
     )
-    write = args.export_ca.write
+    with open(args.export_ca, 'wb') as export_ca_file:
+      write = export_ca_file.write
       for key_pair in SQLite3Storage(
         db_path,
         table_prefix='cas',
@@ -1139,4 +1161,3 @@ def manage(argv=None):
             encryption_algorithm=encryption_algorithm,
           ),
         )
-    args.export_ca.close()

caucase/test.py

@@ -25,7 +25,6 @@ Test suite
 """
 # pylint: disable=too-many-lines, too-many-public-methods
 from __future__ import absolute_import
-import contextlib
 from Cookie import SimpleCookie
 import datetime
 import errno
@@ -305,25 +304,14 @@ def print_buffer_on_error(func):
     try:
       return func(self, *args, **kw)
     except Exception: # pragma: no cover
-      sys.stdout.write(utils.toBytes(os.linesep))
-      sys.stdout.write(self.caucase_test_output.getvalue())
+      stdout = utils.toUnicodeWritableStream(sys.stdout)
+      stdout.write(os.linesep)
+      stdout.write(
+        self.caucase_test_output.getvalue().decode('ascii', 'replace'),
+      )
       raise
   return wrapper
 
-@contextlib.contextmanager
-def captureStdout():
-  """
-  Replace stdout with a BytesIO object for the duration of the context manager,
-  and provide it to caller.
-  """
-  orig_stdout = sys.stdout
-  sys.stdout = stdout = BytesIO()
-  try:
-    yield stdout
-  finally:
-    sys.stdout = orig_stdout
-
-@unittest.skipIf(sys.version_info >= (3, ), 'Caucase currently supports python 2 only')
 class CaucaseTest(unittest.TestCase):
   """
   Test a complete caucase setup: spawn a caucase-http server on CAUCASE_NETLOC
@@ -356,6 +344,9 @@ class CaucaseTest(unittest.TestCase):
     self._server_backup_path = os.path.join(server_dir, 'backup')
     self._server_cors_store  = os.path.join(server_dir, 'cors.key')
     # pylint: enable=bad-whitespace
+    # Using a BytesIO for caucased output here, because stdout/stderr do not
+    # necessarily have a known encoding, for example when output is a pipe
+    # (to a file, ...). caucased must deal with this.
     self.caucase_test_output = BytesIO()
     os.mkdir(self._server_backup_path)
 
@@ -497,7 +488,7 @@ class CaucaseTest(unittest.TestCase):
     )
 
   def _getClientCRL(self):
-    with open(self._client_crl) as crl_pem_file:
+    with open(self._client_crl, 'rb') as crl_pem_file:
       return x509.load_pem_x509_crl(
         crl_pem_file.read(),
         _cryptography_backend
@@ -612,7 +603,10 @@ class CaucaseTest(unittest.TestCase):
 
     Returns stdout.
     """
-    with captureStdout() as stdout:
+    # Using a BytesIO for caucased output here, because stdout/stderr do not
+    # necessarily have a known encoding, for example when output is a pipe
+    # (to a file, ...). caucase must deal with this.
+    stdout = BytesIO()
     try:
       cli.main(
         argv=(
@@ -622,10 +616,11 @@ class CaucaseTest(unittest.TestCase):
           '--crl', self._client_crl,
           '--user-crl', self._client_user_crl,
         ) + argv,
+        stdout=stdout,
       )
     except SystemExit:
       pass
-    return stdout.getvalue()
+    return stdout.getvalue().decode('ascii')
 
   @staticmethod
   def _setCertificateRemainingLifeTime(key, crt, delta):
@@ -1676,7 +1671,10 @@ class CaucaseTest(unittest.TestCase):
       """
       Non-standard shorthand for invoking the WSGI application.
       """
-      environ.setdefault('wsgi.errors', self.caucase_test_output)
+      environ.setdefault(
+        'wsgi.errors',
+        utils.toUnicodeWritableStream(self.caucase_test_output),
+      )
       environ.setdefault('wsgi.url_scheme', 'http')
       environ.setdefault('SERVER_NAME', server_name)
       environ.setdefault('SERVER_PORT', str(server_http_port))
@@ -2294,29 +2292,31 @@ class CaucaseTest(unittest.TestCase):
     os.unlink(self._server_db)
     os.unlink(self._server_key)
 
-    with captureStdout() as stdout:
-      cli.key_id([
-        '--private-key', user_key_path, user2_key_path, user2_new_key_path,
-      ])
+    stdout = BytesIO()
+    cli.key_id(
+      ['--private-key', user_key_path, user2_key_path, user2_new_key_path],
+      stdout=stdout,
+    )
     key_id_dict = dict(
-      line.rsplit(' ', 1)
+      line.decode('ascii').rsplit(' ', 1)
       for line in stdout.getvalue().splitlines()
     )
     key_id = key_id_dict.pop(user_key_path)
     key2_id = key_id_dict.pop(user2_key_path)
     new_key2_id = key_id_dict.pop(user2_new_key_path)
     self.assertFalse(key_id_dict)
-    with captureStdout() as stdout:
-      cli.key_id([
-        '--backup', backup_path,
-      ])
+    stdout = BytesIO()
+    cli.key_id(
+      ['--backup', backup_path],
+      stdout=stdout,
+    )
     self.assertItemsEqual(
       [
         backup_path,
         '  ' + key_id,
         '  ' + key2_id,
       ],
-      stdout.getvalue().splitlines(),
+      stdout.getvalue().decode('ascii').splitlines(),
     )
 
     try:
@@ -2410,17 +2410,18 @@ class CaucaseTest(unittest.TestCase):
     if not backup_path_list: # pragma: no cover
       raise AssertionError('Backup file not created after 1 second')
     backup_path, = glob.glob(backup_glob)
-    with captureStdout() as stdout:
-      cli.key_id([
-        '--backup', backup_path,
-      ])
+    stdout = BytesIO()
+    cli.key_id(
+      ['--backup', backup_path],
+      stdout=stdout,
+    )
     self.assertItemsEqual(
       [
         backup_path,
         '  ' + key_id,
         '  ' + new_key2_id,
       ],
-      stdout.getvalue().splitlines(),
+      stdout.getvalue().decode('ascii').splitlines(),
     )
 
     # Now, push a lot of data to exercise chunked checksum in backup &
@@ -2444,17 +2445,18 @@ class CaucaseTest(unittest.TestCase):
     if not backup_path_list: # pragma: no cover
       raise AssertionError('Backup file took too long to be created')
     backup_path, = glob.glob(backup_glob)
-    with captureStdout() as stdout:
-      cli.key_id([
-        '--backup', backup_path,
-      ])
+    stdout = BytesIO()
+    cli.key_id(
+      ['--backup', backup_path],
+      stdout=stdout,
+    )
     self.assertItemsEqual(
       [
         backup_path,
         '  ' + key_id,
         '  ' + new_key2_id,
       ],
-      stdout.getvalue().splitlines(),
+      stdout.getvalue().decode('ascii').splitlines(),
     )
     self._stopServer()
     os.unlink(self._server_db)
@@ -2510,7 +2512,7 @@ class CaucaseTest(unittest.TestCase):
       self.assertTrue(os.path.exists(exported_ca), exported_ca)
       server_db2 = self._server_db + '2'
       self.assertFalse(os.path.exists(server_db2), server_db2)
-      with captureStdout() as stdout:
+      stdout = BytesIO()
       caucase.http.manage(
         argv=(
           '--db', server_db2,
@@ -2519,6 +2521,7 @@ class CaucaseTest(unittest.TestCase):
           # Twice, for code coverage...
           '--import-crl', self._client_crl,
         ),
+        stdout=stdout,
       )
       self.assertTrue(os.path.exists(server_db2), server_db2)
       self.assertEqual(
@@ -2526,7 +2529,7 @@ class CaucaseTest(unittest.TestCase):
           'Imported 1 CA certificates',
           'Revoked 1 certificates (1 were already revoked)',
         ],
-        stdout.getvalue().splitlines(),
+        stdout.getvalue().decode('ascii').splitlines(),
       )
     finally:
       caucase.http.getBytePass = getBytePass_orig
@@ -2729,7 +2732,7 @@ class CaucaseTest(unittest.TestCase):
     until_network_issue = UntilEvent(network_issue_event)
     # pylint: disable=protected-access
     cli.RetryingCaucaseClient._until = until_network_issue
-    cli.RetryingCaucaseClient._log_file = self.caucase_test_output
+    cli.RetryingCaucaseClient._log_file = StringIO()
     # pylint: enable=protected-access
     until_network_issue.action = ON_EVENT_EXPIRE
     original_HTTPConnection = cli.RetryingCaucaseClient.HTTPConnection

caucase/utils.py

@@ -26,6 +26,7 @@ Small-ish functions needed in many places.
 from __future__ import absolute_import, print_function
 from binascii import a2b_base64, b2a_base64
 import calendar
+import codecs
 from collections import defaultdict
 import datetime
 import email
@@ -499,6 +500,17 @@ def toBytes(value, encoding='ascii'):
   """
   return value if isinstance(value, bytes) else value.encode(encoding)
 
+def toUnicodeWritableStream(writable_stream, encoding='ascii'):
+  """
+  Convert writable_stream into a writable stream accepting unicode.
+  If writable_stream already accepts unicode, returns it.
+  Otherwise, returns a writable stream accepting unicode, and sending it to
+  writable_stream encoded with given encoding.
+  """
+  if getattr(writable_stream, 'encoding', None) is not None:
+    return writable_stream
+  return codecs.getwriter(encoding)(writable_stream)
+
 def interruptibleSleep(duration): # pragma: no cover
   """
   Like sleep, but raises SleepInterrupt when interrupted by KeyboardInterrupt

setup.py

@@ -20,15 +20,10 @@
 # See https://www.nexedi.com/licensing for rationale and options.
 
 from setuptools import setup, find_packages
-import glob
-import os
-import sys
 import versioneer
 
-long_description = open("README.rst").read() + "\n"
-for f in sorted(glob.glob(os.path.join('caucase', 'README.*.rst'))):
-  long_description += '\n' + open(f).read() + '\n'
-  long_description += open("CHANGES.txt").read() + "\n"
+with open("README.rst") as readme, open("CHANGES.txt") as changes:
+  long_description = readme.read() + "\n" + changes.read() + "\n"
 
 setup(
   name='caucase',
@@ -71,5 +66,5 @@ setup(
     ]
   },
   test_suite='caucase.test',
-  use_2to3=sys.version_info >= (3, ),
+  use_2to3=True,
 )