[ovs-dev,v4,2/2] python: replace pyOpenSSL with ssl

Currently, pyOpenSSL is half-deprecated upstream and so it's removed on
some distributions (for example on CentOS Stream 9,
https://issues.redhat.com/browse/CS-336), but since OVS only
supports Python 3 it's possible to replace pyOpenSSL with "import ssl"
included in base Python 3.

Stream recv and send had to be splitted as _recv and _send, since SSLError
is a subclass of socket.error and so it was not possible to except for
SSLWantReadError and SSLWantWriteError in recv and send of SSLStream.

TCPstream._open cannot be used in SSLStream, since Python ssl module
requires the SSL socket to be created before connecting it, so
SSLStream._open needs to create the socket, create SSL socket and then
connect the SSL socket.

Reported-by: Timothy Redaelli <tredaelli@redhat.com>
Reported-at: https://bugzilla.redhat.com/1988429
Signed-off-by: Timothy Redaelli <tredaelli@redhat.com>
---
v3 -> v4:
 - Remove useless ValueError in self.socket.shutdown, as reported by
   Terry Wilson. It was wrongly here due to some previous tests, but
   it's not needed.
---
 .ci/linux-prepare.sh |  2 +-
 .cirrus.yml          |  2 +-
 .travis.yml          |  1 -
 python/ovs/poller.py |  6 +--
 python/ovs/stream.py | 91 ++++++++++++++++++++++++++------------------
 tests/ovsdb-idl.at   |  2 +-
 6 files changed, 60 insertions(+), 44 deletions(-)

Acked-by: Terry Wilson <twilson@redhat.com>
Tested-by: Terry Wilson <twilson@redhat.com>

On Fri, Oct 29, 2021 at 6:12 PM Timothy Redaelli <tredaelli@redhat.com> wrote:
>
> Currently, pyOpenSSL is half-deprecated upstream and so it's removed on
> some distributions (for example on CentOS Stream 9,
> https://issues.redhat.com/browse/CS-336), but since OVS only
> supports Python 3 it's possible to replace pyOpenSSL with "import ssl"
> included in base Python 3.
>
> Stream recv and send had to be splitted as _recv and _send, since SSLError
> is a subclass of socket.error and so it was not possible to except for
> SSLWantReadError and SSLWantWriteError in recv and send of SSLStream.
>
> TCPstream._open cannot be used in SSLStream, since Python ssl module
> requires the SSL socket to be created before connecting it, so
> SSLStream._open needs to create the socket, create SSL socket and then
> connect the SSL socket.
>
> Reported-by: Timothy Redaelli <tredaelli@redhat.com>
> Reported-at: https://bugzilla.redhat.com/1988429
> Signed-off-by: Timothy Redaelli <tredaelli@redhat.com>
> ---
> v3 -> v4:
>  - Remove useless ValueError in self.socket.shutdown, as reported by
>    Terry Wilson. It was wrongly here due to some previous tests, but
>    it's not needed.
> ---
>  .ci/linux-prepare.sh |  2 +-
>  .cirrus.yml          |  2 +-
>  .travis.yml          |  1 -
>  python/ovs/poller.py |  6 +--
>  python/ovs/stream.py | 91 ++++++++++++++++++++++++++------------------
>  tests/ovsdb-idl.at   |  2 +-
>  6 files changed, 60 insertions(+), 44 deletions(-)
>
> diff --git a/.ci/linux-prepare.sh b/.ci/linux-prepare.sh
> index c55125cf7..b9b499bad 100755
> --- a/.ci/linux-prepare.sh
> +++ b/.ci/linux-prepare.sh
> @@ -21,7 +21,7 @@ make -j4 HAVE_LLVM= HAVE_SQLITE= install
>  cd ..
>
>  pip3 install --disable-pip-version-check --user \
> -    flake8 hacking sphinx pyOpenSSL wheel setuptools
> +    flake8 hacking sphinx wheel setuptools
>  pip3 install --user --upgrade docutils
>  pip3 install --user  'meson==0.47.1'
>
> diff --git a/.cirrus.yml b/.cirrus.yml
> index 480fea242..a7ae793bc 100644
> --- a/.cirrus.yml
> +++ b/.cirrus.yml
> @@ -9,7 +9,7 @@ freebsd_build_task:
>
>    env:
>      DEPENDENCIES: automake libtool gmake gcc wget openssl python3
> -    PY_DEPS:      sphinx|openssl
> +    PY_DEPS:      sphinx
>      matrix:
>        COMPILER: gcc
>        COMPILER: clang
> diff --git a/.travis.yml b/.travis.yml
> index 51d051108..c7aeede06 100644
> --- a/.travis.yml
> +++ b/.travis.yml
> @@ -17,7 +17,6 @@ addons:
>        - libjemalloc-dev
>        - libnuma-dev
>        - libpcap-dev
> -      - python3-openssl
>        - python3-pip
>        - python3-sphinx
>        - libelf-dev
> diff --git a/python/ovs/poller.py b/python/ovs/poller.py
> index 3624ec865..157719c3a 100644
> --- a/python/ovs/poller.py
> +++ b/python/ovs/poller.py
> @@ -26,9 +26,9 @@ if sys.platform == "win32":
>      import ovs.winutils as winutils
>
>  try:
> -    from OpenSSL import SSL
> +    import ssl
>  except ImportError:
> -    SSL = None
> +    ssl = None
>
>  try:
>      from eventlet import patcher as eventlet_patcher
> @@ -73,7 +73,7 @@ class _SelectSelect(object):
>      def register(self, fd, events):
>          if isinstance(fd, socket.socket):
>              fd = fd.fileno()
> -        if SSL and isinstance(fd, SSL.Connection):
> +        if ssl and isinstance(fd, ssl.SSLSocket):
>              fd = fd.fileno()
>
>          if sys.platform != 'win32':
> diff --git a/python/ovs/stream.py b/python/ovs/stream.py
> index f5a520862..ac5b0fd0c 100644
> --- a/python/ovs/stream.py
> +++ b/python/ovs/stream.py
> @@ -22,9 +22,9 @@ import ovs.socket_util
>  import ovs.vlog
>
>  try:
> -    from OpenSSL import SSL
> +    import ssl
>  except ImportError:
> -    SSL = None
> +    ssl = None
>
>  if sys.platform == 'win32':
>      import ovs.winutils as winutils
> @@ -322,6 +322,12 @@ class Stream(object):
>          The recv function will not block waiting for data to arrive.  If no
>          data have been received, it returns (errno.EAGAIN, "") immediately."""
>
> +        try:
> +            return self._recv(n)
> +        except socket.error as e:
> +            return (ovs.socket_util.get_exception_errno(e), "")
> +
> +    def _recv(self, n):
>          retval = self.connect()
>          if retval != 0:
>              return (retval, "")
> @@ -331,10 +337,7 @@ class Stream(object):
>          if sys.platform == 'win32' and self.socket is None:
>              return self.__recv_windows(n)
>
> -        try:
> -            return (0, self.socket.recv(n))
> -        except socket.error as e:
> -            return (ovs.socket_util.get_exception_errno(e), "")
> +        return (0, self.socket.recv(n))
>
>      def __recv_windows(self, n):
>          if self._read_pending:
> @@ -396,6 +399,12 @@ class Stream(object):
>          Will not block.  If no bytes can be immediately accepted for
>          transmission, returns -errno.EAGAIN immediately."""
>
> +        try:
> +            return self._send(buf)
> +        except socket.error as e:
> +            return -ovs.socket_util.get_exception_errno(e)
> +
> +    def _send(self, buf):
>          retval = self.connect()
>          if retval != 0:
>              return -retval
> @@ -409,10 +418,7 @@ class Stream(object):
>          if sys.platform == 'win32' and self.socket is None:
>              return self.__send_windows(buf)
>
> -        try:
> -            return self.socket.send(buf)
> -        except socket.error as e:
> -            return -ovs.socket_util.get_exception_errno(e)
> +        return self.socket.send(buf)
>
>      def __send_windows(self, buf):
>          if self._write_pending:
> @@ -769,35 +775,42 @@ class SSLStream(Stream):
>      def check_connection_completion(sock):
>          try:
>              return Stream.check_connection_completion(sock)
> -        except SSL.SysCallError as e:
> +        except ssl.SSLSyscallError as e:
>              return ovs.socket_util.get_exception_errno(e)
>
>      @staticmethod
>      def needs_probes():
>          return True
>
> -    @staticmethod
> -    def verify_cb(conn, cert, errnum, depth, ok):
> -        return ok
> -
>      @staticmethod
>      def _open(suffix, dscp):
> -        error, sock = TCPStream._open(suffix, dscp)
> -        if error:
> -            return error, None
> +        address = ovs.socket_util.inet_parse_active(suffix, 0)
> +        family, sock = ovs.socket_util.inet_create_socket_active(
> +                socket.SOCK_STREAM, address)
> +        if sock is None:
> +            return family, sock
>
>          # Create an SSL context
> -        ctx = SSL.Context(SSL.SSLv23_METHOD)
> -        ctx.set_verify(SSL.VERIFY_PEER, SSLStream.verify_cb)
> -        ctx.set_options(SSL.OP_NO_SSLv2 | SSL.OP_NO_SSLv3)
> +        ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
> +        ctx.verify_mode = ssl.CERT_REQUIRED
> +        ctx.options |= ssl.OP_NO_SSLv2
> +        ctx.options |= ssl.OP_NO_SSLv3
>          # If the client has not set the SSL configuration files
>          # exception would be raised.
> -        ctx.use_privatekey_file(Stream._SSL_private_key_file)
> -        ctx.use_certificate_file(Stream._SSL_certificate_file)
>          ctx.load_verify_locations(Stream._SSL_ca_cert_file)
> +        ctx.load_cert_chain(Stream._SSL_certificate_file,
> +                            Stream._SSL_private_key_file)
> +        ssl_sock = ctx.wrap_socket(sock, do_handshake_on_connect=False)
>
> -        ssl_sock = SSL.Connection(ctx, sock)
> -        ssl_sock.set_connect_state()
> +        # Connect
> +        error = ovs.socket_util.inet_connect_active(ssl_sock, address, family,
> +                                                    dscp)
> +        if not error:
> +            try:
> +                ssl_sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
> +            except socket.error as e:
> +                ssl_sock.close()
> +                return ovs.socket_util.get_exception_errno(e), None
>          return error, ssl_sock
>
>      def connect(self):
> @@ -809,40 +822,44 @@ class SSLStream(Stream):
>          # TCP Connection is successful. Now do the SSL handshake
>          try:
>              self.socket.do_handshake()
> -        except SSL.WantReadError:
> +        except ssl.SSLWantReadError:
>              return errno.EAGAIN
> -        except SSL.SysCallError as e:
> +        except ssl.SSLSyscallError as e:
>              return ovs.socket_util.get_exception_errno(e)
>
>          return 0
>
>      def recv(self, n):
>          try:
> -            return super(SSLStream, self).recv(n)
> -        except SSL.WantReadError:
> +            return super(SSLStream, self)._recv(n)
> +        except ssl.SSLWantReadError:
>              return (errno.EAGAIN, "")
> -        except SSL.SysCallError as e:
> +        except ssl.SSLSyscallError as e:
>              return (ovs.socket_util.get_exception_errno(e), "")
> -        except SSL.ZeroReturnError:
> +        except ssl.SSLZeroReturnError:
>              return (0, "")
> +        except socket.error as e:
> +            return (ovs.socket_util.get_exception_errno(e), "")
>
>      def send(self, buf):
>          try:
> -            return super(SSLStream, self).send(buf)
> -        except SSL.WantWriteError:
> +            return super(SSLStream, self)._send(buf)
> +        except ssl.SSLWantWriteError:
>              return -errno.EAGAIN
> -        except SSL.SysCallError as e:
> +        except ssl.SSLSyscallError as e:
> +            return -ovs.socket_util.get_exception_errno(e)
> +        except socket.error as e:
>              return -ovs.socket_util.get_exception_errno(e)
>
>      def close(self):
>          if self.socket:
>              try:
> -                self.socket.shutdown()
> -            except SSL.Error:
> +                self.socket.shutdown(socket.SHUT_RDWR)
> +            except socket.error:
>                  pass
>          return super(SSLStream, self).close()
>
>
> -if SSL:
> +if ssl:
>      # Register SSL only if the OpenSSL module is available
>      Stream.register_method("ssl", SSLStream)
> diff --git a/tests/ovsdb-idl.at b/tests/ovsdb-idl.at
> index 501c13b81..0f229b2f9 100644
> --- a/tests/ovsdb-idl.at
> +++ b/tests/ovsdb-idl.at
> @@ -225,7 +225,7 @@ m4_define([OVSDB_CHECK_IDL_TCP6_MULTIPLE_REMOTES_PY],
>  m4_define([OVSDB_CHECK_IDL_SSL_PY],
>    [AT_SETUP([$1 - Python3 - SSL])
>     AT_SKIP_IF([test "$HAVE_OPENSSL" = no])
> -   $PYTHON3 -c "import OpenSSL.SSL"
> +   $PYTHON3 -c "import ssl"
>     SSL_PRESENT=$?
>     AT_SKIP_IF([test $SSL_PRESENT != 0])
>     AT_KEYWORDS([ovsdb server idl positive Python with ssl socket $5])
> --
> 2.31.1
>

On 11/1/21 15:27, Terry Wilson wrote:
> Acked-by: Terry Wilson <twilson@redhat.com>
> Tested-by: Terry Wilson <twilson@redhat.com>
> 
> On Fri, Oct 29, 2021 at 6:12 PM Timothy Redaelli <tredaelli@redhat.com> wrote:
>>
>> Currently, pyOpenSSL is half-deprecated upstream and so it's removed on
>> some distributions (for example on CentOS Stream 9,
>> https://issues.redhat.com/browse/CS-336), but since OVS only
>> supports Python 3 it's possible to replace pyOpenSSL with "import ssl"
>> included in base Python 3.
>>
>> Stream recv and send had to be splitted as _recv and _send, since SSLError
>> is a subclass of socket.error and so it was not possible to except for
>> SSLWantReadError and SSLWantWriteError in recv and send of SSLStream.
>>
>> TCPstream._open cannot be used in SSLStream, since Python ssl module
>> requires the SSL socket to be created before connecting it, so
>> SSLStream._open needs to create the socket, create SSL socket and then
>> connect the SSL socket.
>>
>> Reported-by: Timothy Redaelli <tredaelli@redhat.com>
>> Reported-at: https://bugzilla.redhat.com/1988429
>> Signed-off-by: Timothy Redaelli <tredaelli@redhat.com>
>> ---
>> v3 -> v4:
>>  - Remove useless ValueError in self.socket.shutdown, as reported by
>>    Terry Wilson. It was wrongly here due to some previous tests, but
>>    it's not needed.
>> ---
>>  .ci/linux-prepare.sh |  2 +-
>>  .cirrus.yml          |  2 +-
>>  .travis.yml          |  1 -
>>  python/ovs/poller.py |  6 +--
>>  python/ovs/stream.py | 91 ++++++++++++++++++++++++++------------------
>>  tests/ovsdb-idl.at   |  2 +-
>>  6 files changed, 60 insertions(+), 44 deletions(-)


Thanks, Terry and Timothy!

I added a NEWS entry about this change, since it's kind of user-visible
in terms of required dependencies, and applied.

Bets regards, Ilya Maximets.